JP2000007710A - Preparation of polymer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prepare a polymer having a specified amt. of long-chain branches introduced into the main chain of the same by forming a polymer in a tubular reactor having a separated stream formed therein and simultaneously bringing the resultant polymer into contact with ethylene and/or an α-olefin for forming the long-chain branches. SOLUTION: 0.1-10 long-chain branches per 1,000 carbon atoms forming a polymer are introduced into the main chain of the polymer. A mixture comprising a feed monomer 2, a polymn. catalyst 3, a monomer 7 for forming long-chain branches, and optionally an inert medium 4 is supplied under pressure through the inlet port 1a of a tubular reactor 1. The mixture forms a gas/liquid separated stream or a gas/liquid/solid separated stream having a continuous gas phase in the flow direction in the tubular reactor 1, and thus, the feed monomer 2 is reacted while the liquid phase in the reactor is transported by the gas phase in the reactor. When the monomer 7 for forming the long-chain branches is the same as the feed monomer 2, the installation of another feed pipe is not necessary.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for efficiently forming a long-chain branch in a polymer by using a tubular reactor and controlling the amount of the long-chain branch introduced.

[0002]

BACKGROUND OF THE INVENTION Conventionally, tank reactors, tube reactors, tower reactors, fluidized bed reactors, special reactors, and the like have been used as reactors. Is selected according to the physical properties of the object to be manufactured. For polymerization of olefins and the like, a tank reactor or a fluidized bed reactor is generally used.

[0003] When a tank type polymerization vessel is used as a polymerization apparatus, liquid phase polymerization such as solution (homogeneous) polymerization using a solvent and slurry polymerization is usually performed. According to such a liquid phase polymerization, a polymer of relatively high quality can be obtained, and there are advantages in that there are few restrictions on the physical properties of the polymer to be produced and operating conditions.

However, in the liquid phase polymerization using the above-described tank reactor, the produced polymer is dissolved or suspended in a polymerization solvent with stirring to form a polymerization solution (polymer solution or slurry) containing the produced polymer. Therefore, it is necessary to increase the stirring power as the viscosity of the polymerization liquid increases. In particular, when industrially producing a high-viscosity (polymer) polymerization liquid, a huge stirring equipment is required, and the stirring energy tends to be enormous.

In the above-mentioned liquid phase polymerization, it is necessary to separate the polymer and the solvent after the polymerization, equipment and energy for this separation are required, and a solvent purification equipment may be required in some cases.

On the other hand, when a fluidized bed reactor is used as a polymerization apparatus, the above-described polymerization is performed while fluidizing a solid such as a catalyst and a produced polymer using a gas medium to form a fluidized bed. Such removal of the reaction medium is generally unnecessary, and the polymer can be produced at low cost. On the other hand, it is necessary to control the gas linear velocity within a range where the fluidized bed can be maintained, and in a reaction system with a large heat of reaction, the polymerization is limited by the amount of heat exchange. And the range of operating conditions is often limited.

Further, in the above-described tank-type reactor or fluidized-bed type reactor, it is difficult to control the physical properties of the polymer by additionally introducing raw materials into an arbitrary position of the reactor in accordance with the degree of polymerization. In order to obtain a polymer having desired physical properties, a plurality of reactors are often used.

A polymerization using a tube reactor (tube reactor) is also known as another polymerization apparatus other than such a reaction apparatus. For example, monomer gas is compressed at a high pressure into a reaction tube and supplied as a supercritical fluid. A high-pressure polymerization reaction (a method for producing high-pressure polyethylene) in which high-pressure polymerization is performed in a substantially liquid phase homogeneous system, or uniform polymerization or slurry polymerization using a liquid medium is known. It is also known that this tube-type reactor is used as a reactor in the post-process of the production process using the above-mentioned tank-type reactor or fluidized-bed reactor and used as a device for adjusting the physical properties of a polymer.

Various polymers are produced using the various reactors described above, and the polymers produced in such a reactor may vary in polymer melt flow rate (MFR) and the like depending on the state of formation of the branched chains. Characteristics change significantly. For example, for polymers having the same composition and the same MFR, the intrinsic viscosity [η] decreases as the number of long-chain branches increases. Conversely, if the intrinsic viscosity [η] is the same, the more long-chain branches, the lower the MFR.

The MFR of such a polymer is a very important property, for example, when molding using a polymer.
For polymers having the same molecular weight, a polymer having a higher MFR has a better resin flow during molding, and is often suitable for producing a good molded body.

[0011] Since the concentration of the polymer in the reactor cannot be so high in the conventionally used reactor, it is difficult to intentionally introduce such long-chain branching, and the long-chain branching is simply and easily performed. A polymerization method and apparatus that can be introduced have been desired.

The present inventor can efficiently form a long-chain branch in the produced polymer by allowing the reaction to proceed under specific conditions using a tubular reactor in which a separated flow is formed, In addition, the inventors have found that the amount of introduced long-chain branches can be controlled, and have completed the present invention.

[0013]

SUMMARY OF THE INVENTION The object of the present invention is to efficiently form long chain branches in a polymer by using a tubular reactor in which polymerization proceeds while forming a separated stream in order to efficiently produce a polymer having desired physical properties. It is intended to provide a way to:

Another object of the present invention is to provide a method for controlling the amount of long-chain branching to be introduced.

[0015]

SUMMARY OF THE INVENTION The present invention provides a tubular reactor in which a separate stream is formed in producing a polymer having from 0.1 to 10 long chain branches per 1000 carbon atoms forming the polymer. And a method for producing a polymer.

In the present invention, the raw material monomer, the polymerization catalyst and, if necessary, the inert medium are supplied to the tubular reactor in a pressurized state, and the raw material monomer and / or the inert medium gas are fed into the reactor. Gas phase and the starting monomers and / or
Or a gas-liquid separation stream having a continuous gas phase in the flow direction in the reactor while coexisting with a liquid phase composed of an inert solvent (the liquid phase may contain the produced polymer as a solid). By forming a gas-liquid-solid separation stream, a long-chain branch can be advantageously formed by reacting a raw material monomer while conveying a liquid phase in a reactor by a gas phase flow in the reactor. .

That is, in the present invention, while producing a polymer in a tubular reactor in which a separated flow is formed, the produced polymer is contacted with ethylene and / or α-olefin which forms a long-chain branch. 0.1 to 1 per 1000 carbon atoms constituting the main chain of the produced polymer.
Introduce 0 long chain branches.

A gas-liquid two-phase fluid or a gas-solid three-phase fluid introduced into a pipe may form a separated flow (for example, "1 Flow Mode", Handbook of Gas-Liquid Two-Phase Flow Technology; Nippon Kikai) (Ed. 1989). In the present invention, in a tubular reactor in which such a separated stream is formed, the polymer being formed is brought into contact with ethylene and / or α-olefin which is a component for forming a long-chain branch under specific conditions. Thus, a long-chain branch is introduced into the polymer. And the introduction amount of such a long-chain branch is
It can be controlled by the conditions at the time of supplying the component that forms the long-chain branch.

[0019]

DETAILED DESCRIPTION OF THE INVENTION Hereinafter, a method for introducing a long-chain branch into the polymer of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing an outline of the steps of the method of the present invention. FIG. 2 is a diagram schematically showing a tube type reactor which can be suitably used in the present invention. FIG. 2 is a view showing an example of a mode of a separated flow formed in a tubular reactor.

In FIG. 1, the tubular reactor used in the present invention is indicated by 1. The tubular reactor 1 has a sectional shape as long as it can form a separated flow in the reactor. Although there is no particular limitation on the size and the like, the inner diameter of the pipe is usually about 1 to 50 cm and the length of the pipe is about 10 to 500 m. Further, two or more reactors having different pipe diameters may be connected. Further, the tubular reactor 1 may be linear or have a curved portion. The tubular reactor 1 may be installed inclined, but is usually installed horizontally.

In FIG. 1, a mixture of a raw material monomer 2, a polymerization catalyst 3, a monomer 7 for forming a long-chain branch and, if necessary, an inert medium 4 is pressurized from a reactor inlet 1a of a tubular reactor 1. Supply by These mixtures form a gas-liquid two-phase, gas-solid two-phase or gas-solid-liquid three-phase separated flow in the tubular reactor 1. When the monomer 7 forming the long-chain branch and the raw material monomer 2 are the same, there is no need to separately provide an introduction pipe for introducing the monomer 7 forming the long-chain branch.

In the present invention, the separated flow means that a gas-liquid, gas-solid or gas-liquid-solid phase flow in a tubular reactor (reactor) forms a gas phase flow almost continuous in the flow direction. A liquid phase, a solid phase or a solid-liquid phase may be continuous or discontinuous. In the present invention, a gas-liquid separation flow and a gas-liquid separation flow are preferable among such separation flows. Specific examples of such a separated flow include a laminar flow, a wavy flow, an annular flow, and an annular spray flow.

FIG. 3 shows an example of such a separated flow. FIG. 3 shows an example in which the separation flow is a gas-liquid separation flow. FIG.
(a) is a laminar flow, the laminar flow in a horizontal pipe,
This is a flow formed by the liquid phase flowing at the bottom of the tube by the action of gravity and the gas phase flowing at the top of the tube, and is a flow in which the gas-liquid interface becomes a substantially flat surface. As shown in FIG. 3B, the wavy flow refers to a flow in which a liquid-phase wave is formed at the gas-liquid interface when the gas-phase flow velocity in the laminar flow increases. As shown in FIG. 3 (c), the annular flow is a flow in which a liquid film is present on the pipe wall and a gas phase is formed at the center of the cross section of the pipe, and substantially contains droplets in the gas phase. Not. The annular spray flow is
Formed when the flow rate of the gas phase is higher than the annular flow,
As shown in FIG. 3 (d), the liquid phase is formed in a liquid film along the tube wall, and the droplets are contained in the gas phase near the center of the cross section.

In the present invention, among these separated streams, an annular stream or an annular spray stream is preferred. The definition of such a flow mode is described in detail in a gas-liquid two-phase flow technology handbook "1 flow mode" (published by the Japan Society of Mechanical Engineers, 1989).

In the present invention, the raw material monomer, components for forming long chain branches and, if necessary, an inert medium are heated by, for example, a heater 5 so that the reactor 1 is pressurized.
Supply within. The pressure at the reactor inlet 1a at this time is usually from atmospheric pressure to 100 kg / cm ² · F, preferably 5 kg / cm ² · F.
５０50 kg / cm ² · F. That is, in the present invention, the pressure at the reactor inlet 1a may be in a pressurized state at the pressure difference between the reactor inlet 1a and the inside of the reactor, particularly the reactor outlet 1b. For example, even if the pressure at the reactor inlet 1a is atmospheric pressure, if the reactor outlet 1b is in a reduced pressure state, the raw material monomers and the like are supplied in a relatively pressurized state.

In the reactor 1, as shown in FIG. 2 and FIG. 3, a part of the supplied raw material monomer and the inert medium is made into a gas phase, and the remainder is made into a liquid phase. Phase.

Among the raw material monomers and the inert medium supplied to the reactor, the boiling point under normal pressure is 200 ° C. or less,
When the temperature is preferably 150 ° C. or lower, particularly preferably 100 ° C. or lower, a gas phase is easily formed in the reactor.

As the inert medium which can be present as a gaseous phase in the reactor, any known non-reactive compound can be used as long as it does not adversely affect the polymerization. For example, as the inert medium, a saturated hydrocarbon having 1 to 20 carbon atoms can be used, and specific examples thereof include methane, ethane, propane, butane, pentane, hexane, heptane, octane, nonane, decane, dodecane, and tetradecane. Aliphatic hydrocarbons such as cyclopentane, methylcyclopentane, cyclohexane, methylcyclohexane, cyclooctane and cyclohexene; and aromatic hydrocarbons such as toluene and ethylbenzene.

As the inert medium, for example, an inert gas such as nitrogen, argon and helium can be used. In particular, in the present invention, the gaseous phase is one having 1 to 2 carbon atoms among the above-mentioned inert gas such as nitrogen and the above-mentioned saturated hydrocarbon.
It is desirably formed of a gas component containing a saturated hydrocarbon of 0, preferably a saturated hydrocarbon having 3 to 10 carbon atoms.

Further, the gaseous phase may contain a raw material monomer gas or an inert gas, and the gaseous phase may be formed only from the raw material monomer gas. Alternatively, it may be formed only from an inert gas, or may be formed from a mixed gas thereof.

The gas phase may contain two or more kinds of raw material monomer gases or two or more kinds of inert gases. The gas phase may contain a gaseous component having another function, for example, hydrogen gas used as a molecular weight regulator.

In the present invention, various polymerizable monomers can be reacted, and a raw material monomer and a catalyst corresponding to a target polymer can be used without any particular limitation. In the present invention, for example, an olefin can be used as a raw material monomer.

In the olefin polymerization, specifically, ethylene, propylene, 1-butene, 1-pentene, 1-hexene,
Linear, branched, cyclic olefins having 2 to 20 carbon atoms such as 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, norbornene, tetracyclododecene, methyltetracyclododecene, etc. Can be homopolymerized or copolymerized. Further, olefins and a non-conjugated diene may be copolymerized, for example, 5-ethylidene-2-norbornene, 5-propylidene-2-norbornene, dicyclopentadiene, cyclic diene such as 5-vinyl-2-norbornene, Chains such as 1,4-hexadiene, 5-methyl-1,5-heptadiene, 6-methyl-1,5-heptadiene, 6-methyl-1,7-octadiene, 7-methyl-1,6-octadiene Non-conjugated dienes can be copolymerized.

Further, an olefin may be copolymerized with a vinylidene aromatic monomer represented by CR ₂ = CR-Ph such as styrene. Here, R is each independently hydrogen or methyl, Ph is a phenyl group or a p-alkyl-substituted phenyl group, and these may have a halogen substituent.

In the present invention, the above vinylidene aromatic monomers such as styrene may be polymerized. The liquid phase formed in the tubular reactor 1 is formed from the remaining raw material monomers that do not form a gas phase and / or the inert medium among the raw material monomers and the inert medium.

Among the raw material monomers and the inert medium, the boiling point under normal pressure is -150 ° C or more, preferably-
Those that are 40 ° C. or more and 350 ° C. or less,
It can be in the liquid phase in the reactor.

As the inert medium forming such a liquid phase, among the above-mentioned saturated hydrocarbons, hydrocarbons having 1 to 20, preferably 3 to 10 carbon atoms are used. The liquid phase may contain two or more kinds of raw material monomers or two or more kinds of inert solvents.

Further, this liquid phase may contain the produced polymer as a solid (slurry). The raw material monomer or inert medium capable of forming a liquid phase in the reactor is usually in a volume ratio of 0.000001 to 10000 with respect to the raw material monomer or inert medium capable of forming a gas phase.
It is fed into the reactor in an amount of 0, preferably 0.001 to 10000.

The catalyst may be supplied in any state of gas, liquid and solid. The catalyst used in the present invention may be any one provided for various polymerizations,
When polymerizing the above-mentioned olefins as an example of the catalyst, for example, an olefin polymerization catalyst comprising a transition metal catalyst component and a co-catalyst component is preferably used.

As the transition metal catalyst component used here, a transition metal compound [A] selected from Groups IVb, Vb and VIb of the periodic table is used, and this transition metal compound is, for example, represented by the following formula (i): Is shown.

ML _x (i) In the formula (i), M is a transition metal selected from Zr, Ti, Hf, V, Nb, Ta and Cr. L is a ligand which coordinates to the transition metal, and is a hydrogen atom, a halogen atom, an oxygen atom, a hydrocarbon group having 1 to 30 carbon atoms which may have a substituent, an alkoxy group, an aryloxy group, a trialkyl A silyl group or an SO ₃ R group (here, R is a hydrocarbon group having 1 to 8 carbon atoms which may have a substituent (atom) such as halogen). x is the valence of the transition metal.

Examples of the halogen include fluorine, chlorine, bromine, iodine and the like. As the hydrocarbon group having 1 to 30 carbon atoms, specifically, methyl group, ethyl group, propyl group, isopropyl group, alkyl group such as butyl group, cyclopentyl group, cycloalkyl group such as cyclohexyl group, phenyl group, Examples include an aryl group such as a tolyl group and a cyclopentagenyl group, and an aralkyl group such as a benzyl group and a neophyl group.

Further, these cycloalkyl group, aryl group and aralkyl group may be partially substituted with a halogen atom, an alkyl group, a trialkylsilyl group or the like.

Further, when the hydrocarbon group is a cycloalkyl group,
When it is an aryl group or an aralkyl group and has a plurality of coordinations, an alkylene group such as an ethylene group or a propylene group, a substituted alkylene group such as an isopropylidene group or a diphenylmethylene group, a silylene group or a dimethylsilylene group, They may be bonded via a substituted silylene group such as a silylene group or a methylphenylsilylene group.

Examples of the alkoxy group include a methoxy group, an ethoxy group and a butoxy group, and examples of the aryloxy group include a phenoxy group. Further, as the transition metal compound [A], a compound represented by the following formula (ii) can also be used.

L ² M ¹ X ₂ ... (Ii) In the above formula (ii), M ¹ is a metal belonging to Group IVb of the periodic table or a lanthanoid series metal, and L ² represents a delocalized π-bonded group. A derivative, imparting a constrained geometry to the metal active site, wherein X is the same or different and is a hydrogen or halogen atom;
A hydrocarbon group, a silyl group or a germyl group containing 0 or more carbon atoms, silicon atoms or germanium atoms.

Among such compounds represented by the formula (ii), a transition metal compound represented by the following formula (ii ') is preferable.

[0049]

Embedded image

In the formula (ii ′), M ¹ is titanium, zirconium or hafnium, and X is the same as described above. C
p is a substituted cyclopentadienyl group having a π bond to M ¹ and having a substituent Z.

Z is oxygen, sulfur, boron or an element of Group IVa of the Periodic Table (eg, silicon, germanium and tin); Y is a ligand containing nitrogen, phosphorus, oxygen or sulfur; And Y may form a condensed ring.

Examples of such a compound represented by the formula (ii) include dimethylsilylene (t-butylamide) (tetramethyl-η ⁵ -cyclopentadienyl) titanium dichloride, [(t-butylamide) ( Tetramethyl-η ⁵ -cyclopentadienyl) -1,2-ethanediyl] titanium dichloride.

These compounds may be used alone or in combination of two or more, or may be used after being diluted with a hydrocarbon or a halogenated hydrocarbon. The transition metal compound as described above can be supplied to the polymerization system in solid or liquid form or additionally supplied. For example, the transition metal compound can be used together with the particulate carrier compound by bringing the transition metal compound into contact with the particulate carrier compound. As a carrier compound,
Specifically, SiO ₂ , Al ₂ O ₃ , B ₂ O ₃ , MgO, Zr
O ₂ , CaO, TiO ₂ , ZnO, Zn ₂ O, SnO ₂ , B
Inorganic compounds such as aO, MgCl ₂ , and NaCl, and resins such as polyethylene, polypropylene, poly-1-butene, poly-4-methyl-1-pentene, and styrene-divinylbenzene copolymer can be used. Carriers can be used in combination of two or more kinds. In addition, this particulate carrier compound may be formed in a particulate form during the contact process with the transition metal compound. Of these, especially MgC
l ₂ and SiO ₂ are preferred. When the transition metal compound is in a liquid state, it may be supplied as it is, or may be supplied after being diluted with an inert solvent or a monomer. When the transition metal compound is a solid, it may be supplied by dissolving or suspending it in an inert medium or monomer.

The cocatalyst component for forming the olefin polymerization catalyst includes [B] an organoaluminum compound, an organoaluminum halogen compound, an aluminum halide compound, an organic boron compound, an organic boron oxy compound, an organic boron halogen compound, a boron halogen compound. And a compound selected from organic aluminum oxy compounds.

The compound group [B] is specifically represented by the following formula (iii) except for the above-mentioned organic aluminum oxy compound. BR _x (iii) In the formula (iii), B is an aluminum atom or a boron atom, and x is a valence of aluminum or boron.

When the compound represented by the formula (iii) is an organoaluminum compound or an organoboron compound, R is an alkyl group having 1 to 30 carbon atoms, and R is an aluminum halide compound or a boron halide compound. In the formula, R is a halogen atom, and when it is an organic aluminum halide or an organic boron halide, R is both an alkyl group having 1 to 30 carbon atoms and a halogen atom.

Examples of the halogen include fluorine, chlorine, bromine and iodine. Specific examples of the alkyl group having 1 to 30 carbon atoms include methyl, ethyl, propyl, isopropyl, butyl, and the like. Examples include an isobutyl group.

The organic aluminum oxy compound is specifically represented by the following formula (iv) or (v).

[0059]

[Formula 2]

In these formulas, R is a hydrocarbon group such as a methyl group, an ethyl group, a propyl group, a butyl group, etc.
Is an integer of 2 or more, preferably 5 to 40. The aluminoxane is an alkyloxyaluminum unit represented by the formula (OAl (R ¹ )) (R ¹ is the same group as R above)
And an alkyloxyaluminum unit represented by the formula (OAl (R ² )) (R ² is different from R ¹ and is the same group as R above)
And a mixed alkyloxyaluminum unit.

Further, R in the alkyloxyaluminum unit may be a halogen or hydrogen alkoxy group, an aryloxy group or a hydroxyl group if it is a part. further,
As aluminoxane, the following formulas (vi) and (vii)
An aluminoxane having two kinds of repeating units represented by the following formulas can also be used.

[0062]

Embedded image

However, in the above formula, n and m are
Each is independently an integer of 1 or more. This aluminoxane has two types of repeating units represented by the above formulas (vi) and (vii), and has a molecular weight of 200 to 2,000, preferably 500 to 2,000 as measured by a freezing point depression method of benzene.
It is in the range of 1000. The aluminoxane represented by the above formulas (vi) and (vii) can usually be obtained by reacting triethylaluminum with water. At this time, 2 represented by the above formulas (vi) and (vii)
Aluminoxane having two kinds of repeating units can be obtained by controlling the amount of alkane actually generated, instead of controlling the ratio of water to triethylaluminum. That is, the reaction is stopped when the actually generated alkane (RH) becomes 2.05 to 2.50 mol, preferably 2.1 to 2.4 mol, per 1 mol of the raw material trimethylaluminum. Thus, an aluminoxane having two types of repeating units represented by the above formulas (vi) and (vii) can be produced.

These compounds may be used in combination of two or more kinds, or may be used after being diluted with a hydrocarbon or a halogenated hydrocarbon. Specific examples of the olefin polymerization catalyst in which the transition metal compound catalyst component and the cocatalyst are appropriately combined include a Ziegler catalyst, a metallocene catalyst, and a vanadium catalyst.

The olefin polymerization catalyst may contain an electron donor, if necessary, in addition to the above-mentioned transition metal catalyst component [A] and co-catalyst component [B]. As the electron donor, for example, an ether compound, a carbonyl compound, an alkoxy compound, or the like can be used.

In the present invention, an olefin may be pre-polymerized on the above-mentioned catalyst component to form a pre-polymerized catalyst. Specifically, the catalyst comprising the above-mentioned transition metal catalyst component and the promoter component is added to the catalyst in an amount of 50 to 20,000 g, preferably 10 to 20,000 g, per 1 g of the transition metal catalyst component.
0 to 15000 g, particularly preferably 300 to 10000 g
It is preferable to use a prepolymerized catalyst obtained by prepolymerizing an olefin in an amount of g.

The transition metal catalyst component to be prepolymerized is preferably supported on the particulate carrier compound as described above. At the time of prepolymerization, an electron donor can be used if necessary.

The olefin to be prepolymerized may be the same as the olefin for the polymerization raw material (main polymerization), and the prepolymerized olefin may be the same as or different from the main polymerization olefin. Also, two or more olefins can be prepolymerized.

The method of the prepolymerization is not particularly limited, except that the olefin is prepolymerized in the above-mentioned amount, and the prepolymerization can be carried out by widely utilizing known prepolymerization methods. For example, the prepolymerization can be performed in a state where the olefin is in a liquid state, can be performed in the presence of an inert solvent, or can be performed under a gas phase condition. Of these, it is preferable to add a prepolymerized olefin and each catalyst component to the inert solvent in the presence of an inert solvent, and to carry out the prepolymerization under relatively mild conditions. At this time, the reaction may be carried out under a condition in which the produced prepolymer is dissolved in the polymerization medium, or may be carried out under a condition in which the prepolymer is not dissolved, but it is preferably carried out under a condition in which the prepolymer is not dissolved. The prepolymerization is usually carried out at about-
It is carried out at 20 to + 100 ° C, preferably at about -20 to + 80 ° C, more preferably at -10 to + 60 ° C. The prepolymerization can be performed in any of a batch system, a semi-continuous system, and a continuous system.

Although the concentration of the catalyst component in the prepolymerization varies depending on the type of the catalyst component, the concentration of the transition metal catalyst component is expressed in terms of transition metal atoms per liter of polymerization volume.
Usually about 0.001 to 5000 mmol, preferably about 0.005 mmol.
01-1000 mmol, particularly preferably 0.1-50
0 mmol.

The cocatalyst component is usually used in an amount of about 0.1 to 1000 mol per mol of transition metal atom in the transition metal catalyst component.
Preferably from about 0.5 to 500 mol, particularly preferably from 1 to 500 mol.
It can be used in an amount of 100 moles.

At the time of the prepolymerization, a molecular weight regulator such as hydrogen may be used. When the prepolymerized catalyst is obtained in a suspended state, the prepolymerized catalyst can be supplied to the reactor in a suspended state, or the prepolymerized catalyst can be supplied separately from the suspension. it can.

The particle size of the prepolymerized catalyst as described above is 10
It is desirable that the thickness be not less than μm, preferably 50 to 500 μm. In the present invention, when the pre-polymerization catalyst is supplied into the reactor, a co-catalyst component can be supplied in addition to the pre-polymerization catalyst. In some cases, this co-catalyst component need not be supplied.

As described above, in the present invention, the polymerization of the raw material monomers is carried out while the liquid phase in the reactor is conveyed by the gas phase flow in the reactor. When a pre-polymerized catalyst is used, the catalyst supplied into the reactor can be effectively used.

In the present invention, when the olefin polymerization catalyst comprising the above-mentioned transition metal catalyst component or prepolymerization catalyst and the cocatalyst component is supplied into the reactor, the cocatalyst component is previously added to an inert solvent. Is preferably supplied to the reactor together with the inert solvent or additionally supplied thereto.

As the inert solvent to be mixed with the cocatalyst component, the same as the inert solvent supplied into the reaction tube can be mentioned, and it is preferable that these are the same.
The pre-mixing of the co-catalyst component and the inert solvent is performed so that the co-catalyst component and the inert solvent are uniformly mixed. Specifically, the co-catalyst component is added to the inert solvent, and The stirring is performed at a temperature of 0.5C for 0.5 to 24 hours. At the time of this pre-mixing, the inert solvent is used in an amount of 25 g per 1 g of the promoter component.
Preferably, it is used in an amount of 0 to 2.5 × 10 ⁷ ml.

This premixing may be performed either in a batch system or a continuous system. When the co-catalyst component is premixed with the inert solvent and supplied into the reactor, the co-catalyst component is sufficiently dispersed in the reaction system, and the co-catalyst component supplied to the reactor is effectively used. can do. For this reason, an amount that substantially corresponds to the minimum amount (calculated value) necessary for the reaction may be supplied into the reactor. When the cocatalyst component is supplied into the reactor in an excessive amount, the activity of the transition metal catalyst component may be reduced, and the polymerization activity per transition metal may be reduced. The polymerization catalyst as described above is supplied from the reactor inlet 1a of the tubular reactor 1.

In the present invention, the components supplied from the reactor inlet 1a form a gas-liquid separation flow or a gas-liquid solid separation flow as described above in the tubular reactor 1, and form the liquid phase or the liquid phase in the reactor. While the solid-liquid phase is being conveyed by a gas phase composed of the raw material monomer and / or an inert medium gas (hereinafter also referred to as a “carrier gas”) in the reactor, the polymerization of the raw material monomer is performed.

In the present invention, a component forming a long-chain branch is brought into contact with the produced polymer while the polymer is produced in the tubular reactor 1. Here, an olefin, a conjugated diene, or the like can be used as a component that forms a long-chain branch. Specifically, for example, ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-
Linear, branched or cyclic olefins having 2 to 20 carbon atoms such as dodecene, norbornene, tetracyclododecene, methyltetracyclododecene; and, for example, 5-ethylidene-2-norbornene, 5-propylidene-2-norbornene , Dicyclopentadiene, cyclic dienes such as 5-vinyl-2-norbornene, 1,4-hexadiene, 5-methyl-1,5
-Heptadiene, 6-methyl-1,5-heptadiene, 6-methyl
Chain conjugated dienes such as -1,7-octadiene and 7-methyl-1,6-octadiene can be used.

Further, CR ₂ = CR-Ph such as styrene
And vinylidene aromatic monomers represented by Here, R is each independently a hydrogen atom or a methyl group, and Ph is a phenyl group or a p-alkyl-substituted phenyl group, which may have a halogen substituent. The components that form such long-chain branches can be used alone or in combination. Further, the component forming the long-chain branch and the monomer (monomer for forming the main chain) introduced into the tubular reactor may be the same or different.

It is considered that the reaction for forming a polymer from a monomer and the reaction for forming a long-chain branch are competitive reactions, and the component for forming a long-chain branch is required to come into contact with the formed polymer at a high concentration. preferable. For example, by performing polymerization while supplying a raw material monomer from the inlet 1a side using a tubular reactor 1 as shown in FIG. 1 or FIG. 2, control is performed so that a polymer having a predetermined long-chain branch can be formed. Easier to do. When introducing long-chain branches, the higher the concentration of the polymer formed in the reactor, the larger the amount of long-chain branches formed. Therefore, by using a tubular reactor,
A long-chain branch can be formed efficiently. In the present invention, the long-chain branching component can be formed in the main chain by supplying the raw material monomer and the long-chain branching component from the inlet 1a. When the component forming the long-chain branch and the starting monomer are the same, a part of the introduced monomer acts as the component forming the long-chain branch.

By setting the reaction conditions so that the content of the polymer in all the components discharged from the discharge port 1b is usually in the range of 35 to 100% by weight, preferably 40 to 90% by weight, Long chains can be efficiently introduced into the chain.

The component forming the long chain branch is as follows:
As shown in FIG. 2, not only the introduction from the inlet 1 a of the tubular reactor 1, but also
, And components that form long-chain branches can be supplied from the side wall supply ports 12, 12,. Similarly, the above-mentioned catalyst component can be additionally added,
A catalyst and a monomer component may be added simultaneously. Further, independent temperature control means 11, 11... Are arranged on the outer periphery of the tube of the tube reactor 1 to partially heat or cool the tube reactor 1 to form long-chain branches. You can also.

The long-chain branches thus formed are contained in an amount of 0.1 to 1 per 1000 carbon atoms constituting the produced polymer.
0, preferably 0.2 to 5, more preferably 0.3
It is formed at a rate of ~ 3. In addition, this long chain branch
Usually, it is composed of 6 or more carbon atoms except for a branch caused by a copolymer monomer. The long-chain branch is usually a hydrocarbon group, and in many cases, the hydrocarbon group is a saturated aliphatic hydrocarbon group, but the hydrocarbon group may have an unsaturated bond. Further, depending on the type of the component that forms the long-chain branch, the long-chain branch may further have a branch, and may further have an aromatic group, or an ester group, a carboxyl group, a hydroxyl group, or the like. It may have a polar group. In addition, an ethylenically unsaturated group can be introduced at the terminal of the long chain branch.

In the method of the present invention, when the starting monomers, the catalyst and the inert medium are supplied from the reactor inlet 1a of the tubular reactor 1 into the tubular reactor to form the above-mentioned separated flow, Generally, the gas linear velocity at the lowest gas linear velocity in the pipe is usually 0.5 to 500 m / sec, preferably 1 to 300 m / sec, particularly preferably 3 to 150 m / sec.
/ Sec.

Here, the gas linear velocity is converted into the gas flow rate (volume) in the reactor by performing temperature / pressure correction and gas-liquid equilibrium calculation on the gas flow rate (volume) at the reactor outlet 1b. It is a value obtained by dividing the gas flow rate when converted only in the reactor through this gas by the flow cross-sectional area of the reactor. The gas flow rate (volume) at the reactor outlet 1b is determined by connecting a gas-liquid separator to the reactor outlet 1b and measuring the gas flow rate discharged from the gas discharge pipe of the gas-liquid separator with a volume flow meter. be able to.

In the polymerization carried out while forming the above-mentioned separated flow in the tubular reactor 1, the polymerization pressure is usually 0.1.
~ 1000 kg / cm ² F, preferably 1.1-100 kg / cm
² F, more preferably 1.5 to 80 kg / cm ² F, and particularly preferably 1.7 to 50 kg / cm ² F.
The polymerization pressure depends on the pressure at the reactor inlet 1a and the pressure at the reactor outlet 1a.
It is an average value with the pressure of b.

In the polymerization reaction using the tubular reactor 1, the average temperature in the reactor is usually -50 to +300.
° C, preferably -20 to + 250 ° C, particularly preferably 2 ° C
0-200 ° C. For example, when a tubular reactor 1 as shown in FIG. 4 is used, a plurality of temperature control means 12a, 12b, 12c,
12d, 12e and a plurality of wall supply ports 11a, 11b, 11c,
11d, and supply pipes 15 such as a monomer supply pipe, a polymerization catalyst supply pipe, and an inert solvent supply pipe at each wall supply port.
a, 15b, 15c, 15d are connected. In FIG.
The side described as 1a is the reactor inlet side, the side described as 1b is the reactor outlet side, and the separated flow is 1b from the 1a side.
Has moved to the side. In addition, the produced | generated polymer is conveyed by the said carrier gas in the state melt | dissolved in the liquid phase or suspended in the liquid phase.

As described above, since the raw material monomer is consumed by polymerization inside the tubular reactor 1, the volume of the gas phase containing a large amount of the raw material monomer generally decreases. The produced polymer is usually contained as a solid in the liquid phase. However, when the inert medium is heated by the heat of polymerization and transitions to the gas phase and the melting point of the produced polymer is low, at the reactor outlet 1b, A liquid phase consisting of only the polymer may be formed.

The liquid phase (reaction liquid containing the polymer) discharged from the reactor outlet 1b is usually sent to a polymer separator 6 such as a hopper to separate the polymer and the reaction liquid (inert medium). . The polymer thus obtained is supplied to, for example, an extruder (not shown). When the liquid phase (polymer liquid) discharged from the reactor outlet 1b substantially contains no solvent or contains only a very small amount, it can be directly introduced into the extruder. It is.

The concentration of the produced polymer in the liquid phase is usually 100 to 35% by weight, preferably 90 to 40% by weight.
Although the concentration may be as high as the weight% or lower, the higher the concentration of the produced polymer, the more efficiently long-chain branches can be formed.

At the outlet 1b of the reactor, a liquid phase consisting of the polymer having a long chain branch as described above or a solution in which the polymer having a long chain branch is dissolved or suspended in a raw material monomer or an inert medium is obtained. .

In the present invention, the flow rate ratio (liquid phase / gas phase) (S / G ratio) of the liquid phase to the gaseous phase at the reactor outlet 1b is a volume flow rate ratio, usually from 0.000001 to 100000, The reaction conditions are set so as to be preferably from 0.000001 to 10000, particularly preferably from 0.000001 to 1000.

The above S / G ratio (volume flow ratio) was determined at the reactor inlet 1a with respect to the total amount of the raw material monomer and the inert medium measured by the flow meter, the temperature in the reactor,
Considering the pressure, the temperature and pressure corrections and the vapor-liquid equilibrium using the Redlich-Kister equation, etc., are calculated by the state equations such as the van der Waals equation and the virial equation. The liquid phase volume flow rate and the gas phase volume flow rate are calculated, and the value obtained by weighting the obtained liquid phase volume flow rate with the polymer volume flow rate is S, and the gas phase volume flow rate obtained above is G. .

The S / G ratio at the outlet 1b of the reactor can be expressed as a mass flow ratio, and the S / G ratio expressed as a mass flow ratio is usually from 0.000001 to 5%.
000, preferably 0.0001 to 500, particularly preferably 0.0001 to 50.

The above S / G ratio (mass flow ratio) is calculated based on the temperature and pressure in the reactor with respect to the total supply amount of the raw material monomer and the inert medium measured by the flow meter at the reactor inlet 1a. And pressure correction using the equation of state, virial equation, and Roult's law, Redli
The liquid-phase mass flow rate and gas-phase mass flow rate in the reactor are calculated by calculating the gas-liquid equilibrium using the ch-Kister equation, etc., and the value obtained by adding the polymer mass flow rate to the obtained liquid phase mass flow rate Is S, and the gas mass flow rate obtained above is G.

The pressure loss per unit length in the tube length direction in the tube reactor 1 as described above is generally 5 kg / cm ² ···
m, preferably 2 kg / cm ² · m or less, particularly preferably 1 kg / cm ² · m or less.

In the present invention, the viscosity of the liquid phase obtained from the reactor outlet 1b as described above is not particularly limited, and a polymerization liquid having a wide viscosity range can be obtained. Usually, a high-viscosity polymer liquid having a liquid phase viscosity at the reactor outlet 1b (at the reactor outlet temperature) of 1,000,000 poise or less, preferably 100,000 poise or less, particularly preferably 50,000 poise or less at its upper limit ( Polymerization liquid). The lower limit of the liquid phase viscosity is not particularly limited, and is usually 1 c
p or more, preferably 10 cp or more.

More specifically, the liquid phase viscosity at the outlet 1b of the reactor, that is, the viscosity of the polymer prepared substantially by the method of the present invention (measured at 230 ° C. and a shear rate of 10 sec ⁻¹ ) is as follows: 1 × is preferably a 10 ² ~1 × 10 ⁶ poise, also preferably a high viscosity of ^{3 × 10 2 ~1 × 10 6} poise, no do not hinder even 1 × 10 ³ poise or more.

The viscosity is determined by measuring the shear stress of the molten polymer using a capillary flow property tester (manufactured by Toyo Seiki Seisaku-sho, Ltd.) and converting the measured shear stress into a viscosity. That is, the stress is obtained by measuring the stress when the molten polymer is extruded from the capillary while changing the shearing speed, and dividing the measured stress by the shearing speed.

The polymer obtained by the method of the present invention as described above is used in an amount of 0.1 to 10, preferably 0.2 to 5, and more preferably 0.3, per 1000 carbon atoms constituting the polymer. Long chain branches are introduced at a rate of ~ 3. Here, the long-chain branch refers to a branch having 6 or more carbon atoms excluding a branch caused by a copolymer monomer.

Further, the MFR of the polymer into which the long-chain branch is introduced as described above,
The MFR of a polymer having the same intrinsic viscosity [η] and having no long-chain branching tends to be lower, and the difference becomes larger as the number of long-chain branching increases.

The density of the polymer into which the long-chain branch is introduced is usually from 0.800 to 1.100 g / cm ³ , preferably from 0.820 to 1.080 g / cm ³ , and more preferably 0.83. It is in the range of 0 to 1.050 g / cm ³ .

According to the present invention, the resulting polymer has an elastic modulus of 1 to 1 × 10 ⁴ MPa, preferably 2 to 5 × 1 MPa.
It can be controlled within the range of 0 ³ MPa, more preferably within the range of 2 to 3 × 10 ³ MPa. The modulus of elasticity of this polymer is usually expressed as a flexural modulus, and the measured value is 2 m in thickness according to ASTM C790.
Using a test piece of m, span distance 32 mm, bending speed 5 m
It is a value measured under the condition of m / min.

[0105]

According to the method of the present invention, the polymer concentration can be increased by using a tubular reactor,
Therefore, the polymer being formed and the component for forming the long-chain branch can be brought into contact with each other at a high concentration. By bringing the two into contact with each other in this manner, a long-chain branch can be efficiently introduced into the main chain. In addition, by adjusting the state of contact between the two, it is possible to control the form of introduction of the long-chain branch.

Further, since a separated flow having a continuous gas phase in the flow direction in the reactor is formed, and the liquid phase is transported by this gas phase flow, the produced polymer is dissolved and the liquid phase becomes a high-viscosity solution. Even so, the tube is hardly clogged in the reactor, and can be transported in the reaction tube only by the carrier gas. Therefore, there is no need to separately provide a transfer power such as a circulation pump, and it is not necessary to stir the high-viscosity solution, so that the polymerization can be performed with little power energy.

Further, the liquid phase (polymer liquid) at the outlet 1b of the reactor does not substantially contain a solvent or contains only a very small amount, so that the equipment for drying the polymer can be greatly simplified. In some cases, it can be directly introduced into the extruder, and the solvent recycling step can be simplified.

As described above, in the present invention, a simple reaction apparatus is used, and the above polymerization is carried out at a low apparatus cost without requiring a particularly large-scale auxiliary equipment such as a large-scale stirrer, a drying equipment, and a high-pressure compression equipment. And there are few restrictions on the viscosity and melting point of the polymer to be produced.

[0109]

EXAMPLES Next, the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples.

In the examples, the S / G ratio (volume flow ratio) was determined as follows. Based on the amount and composition of the raw materials (including monomers and solvents) fed to the reactor, the vapor-liquid equilibrium at the temperature and pressure inside the reactor is known to Redlic.
The liquid / gas volumetric flow ratio (S / G ratio) of the raw material was calculated by the calculation using the h-Kister equation.

The S / G ratio based on the volume flow ratio was obtained by weighting the flow rate of the polyethylene from the reactor outlet 1b and dividing this value by the above gas flow rate.

The MI of the polyethylene obtained in the following examples was 190 in accordance with ASTM D1238.
It is a value measured under a load of 2.16 kg. Further, the polyethylene and ethylene / α obtained in the following Examples
-The intrinsic viscosity [η] of the olefin copolymer is determined by completely dissolving 25 mg of the polymer in 25 ml of decalin at a temperature of 135 ° C.
It is the value measured in.

The long-chain branching number of polyethylene obtained in the following Examples was determined by using a LA500 nuclear magnetic resonance apparatus (manufactured by JEOL Ltd.) to prepare a 200 mg sample of o-dichlorobenzene / deuterated chloroform. The solution was dissolved in 2.5 ml of a 4/1 solvent, and ¹³ C (125.7 MHz) was measured at a temperature of 120 ° C. and 30,000 times at a cumulative number of 30,000 to measure branches having 6 or more carbon atoms.

[0114]

Example 1 A raw material monomer, a titanium-based metallocene-based polymerization catalyst, a boron compound, an alkylaluminum and n-decane were supplied into a tubular reactor (a steel tube of 3 / 4B × 22 m), and the raw materials were supplied under the following conditions. The monomer ethylene was polymerized.

Ethylene / hydrogen / n-decane = 92/1/7 (molar ratio) Gas linear velocity (reactor inlet) = 25 m / sec, reaction temperature = 150 ° C. reaction pressure = 8 kg / cm ² · FS / G Ratio (volume flow ratio) = 1.0 × 10 ⁻⁵ S / G ratio (mass flow ratio) = 1.0 × 10 ⁻³ Liquid phase (polymer liquid) concentration (reactor outlet) = 80% by weight Liquid phase ( Polymer liquid) viscosity (reactor outlet) = 10,000 po
ise In the above polymerization, a gas-liquid separation flow was formed in the reaction tube.

By the above polymerization, at the reactor outlet,
300 kg polymerization amount per 1 g of transition metal compound catalyst component
And a polyethylene of good quality was obtained at a flow rate of 0.1 kg / hr.

The MI of the polyethylene obtained at the outlet of the reactor
Was 7.1 g / 10 min, and the density of this polyethylene was 0.95 g / cm ³ . The number of long-chain branches having 6 or more carbon atoms in the produced polyethylene was 0.45 per 1000 carbon atoms constituting the main chain.

In the above polymerization, the reaction heat could be removed only by cooling with the reactor jacket.

[0119]

Example 2 A raw material monomer, a titanium-based metallocene-based polymerization catalyst, a boron compound, an alkylaluminum, and n-decane were supplied into a tubular reactor (a steel tube of 3 / 4B × 22 m), and the raw materials were obtained under the following conditions. Ethylene as a monomer and 1-octene as an α-olefin having 8 carbon atoms were copolymerized.

Ethylene / hydrogen / α-olefin / n-decane = 95 / 0.5 / 2 / 2.5 (molar ratio) Gas linear velocity (reactor inlet) = 7 m / sec, reaction temperature = 130 ° C., reaction Pressure = 14 kg / cm ² · FS / G ratio (volume flow ratio) = 4.0 × 10 ⁻⁵ S / G ratio (mass flow ratio) = 4.0 × 10 ⁻³ Liquid phase (polymer liquid) concentration ( Reactor outlet) = 80% by weight Liquid phase (polymer liquid) viscosity (Reactor outlet) = 10000 po
ise In the above polymerization, a gas-liquid separation flow was formed in the reaction tube.

According to the above polymerization, at the reactor outlet,
The amount of polymerization per 1 g of the transition metal compound catalyst component is 1000
An ethylene / α-olefin copolymer of Kg and good quality was obtained at a flow rate of 0.1 kg / hr.

The MI of the ethylene / α-olefin copolymer obtained at the outlet of the reactor was 5.0 g / 10 min.
The intrinsic viscosity [η] of this ethylene / α-olefin copolymer is 1.13 dl / g, and the number of long chain branches determined by the correlation between the intrinsic viscosity [η] and MI is 0 per 1000 carbon atoms. .6.

In the above polymerization, the reaction heat could be removed only by cooling with the reactor jacket.

[Brief description of the drawings]

FIG. 1 is a diagram showing an outline of the steps of the method of the present invention.

FIG. 2 is a diagram schematically showing a tube reactor used in the present invention.

FIG. 3 is a diagram showing an example of a mode of a separated flow formed in a tubular reactor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Tubular reactor 2 ... Raw material monomer 3 ... Polymerization catalyst 4 ... Inert medium 5 ... Heating apparatus 1a ... Reactor inlet 1b ... Reactor outlet 6 ...・ Polymer separator 7 ・ ・ ・ Monomer for forming long chain branch 11 ・ ・ ・ Wall supply port 12 ・ ・ ・ Temperature control means

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Atsushi Kobata 1-2-1 Waki, Waki-machi, Kuga-gun, Yamaguchi Prefecture F-term in Mitsui Chemicals, Inc. 4J011 AA05 BB03 BB07 BB17 DA03 DA04 DB17 HB02 HB06 HB14 HB24 4J100 AA02P AA03P AA04P AA07P AA15P AA16P AA17P AA19P AA21P AR11Q AR22Q AR25Q AS00Q BC27Q BC37Q CA01 CA04 FA02 FA08 FA09 FA10 FA27 FA47

Claims (9)

[Claims] 1. A method for producing a polymer having 0.1 to 10 long-chain branches per 1000 carbon atoms forming the polymer, using a tubular reactor in which a separated flow is formed. A method for producing a polymer, comprising: 2. A raw material monomer, a polymerization catalyst and an inert medium, if necessary, are supplied to the tubular reactor according to claim 1 in a pressurized state, and the raw material monomer and / or A gas phase composed of an inert medium gas and a liquid phase composed of a raw material monomer and / or an inert solvent (the liquid phase may contain the produced polymer as a solid) are allowed to coexist, and the flow in the reactor is controlled. By forming a gas-liquid separation flow or a gas-liquid-solid separation flow having a continuous gas phase in the direction, the raw monomer is reacted while the liquid phase in the reactor is transported by the gas phase flow in the reactor. The method of claim 1, wherein: 3. The method according to claim 1, wherein the long-chain branch is a branch having 6 or more carbon atoms except for a branch caused by a copolymer monomer. 4. The method according to claim 1, wherein an annular stream or an annular spray stream is formed in the tubular reactor. 5. The flow rate ratio between a liquid phase and a gaseous phase (liquid phase / gas phase) at the outlet of the tubular reactor is set to a volume flow rate ratio of 0.000001 to 0.0001.
2. The method according to claim 1, wherein the number is 100,000. 6. The method according to claim 6, wherein the raw material monomer is ethylene and / or
2. The method according to claim 1, wherein the method comprises an α-olefin. 7. The method according to claim 1, wherein said long-chain branching ethylene and / or α-olefin is additionally supplied from a wall supply port provided in a tubular reactor.
The method described in the section. 8. The method according to claim 1, wherein at least one
The method of claim 1 wherein the two polymerization conditions control the amount of long chain branching introduced into the polymer that forms a substantially discontinuous reaction field. 9. The method according to claim 1, wherein the tubular reactor has wall supply ports and / or independent temperature control means at different positions in the flow direction.