KR102550083B1 - Supported hybrid catalyst and method for preparing polypropylene using the same - Google Patents

Abstract

In the present invention, a novel hybrid supported catalyst, including a heterogeneous transition metal compound having a specific structure, that is easy to prepare polypropylene having two melting points having a temperature difference of a certain level or more, and a method for producing polypropylene using the same is provided.

Description

Hybrid supported catalyst and method for producing polypropylene using the same {SUPPORTED HYBRID CATALYST AND METHOD FOR PREPARING POLYPROPYLENE USING THE SAME}

The present invention relates to a novel supported hybrid catalyst and a method for producing polypropylene using the same.

Polypropylene has been conventionally used as a general-purpose resin in various fields due to its low specific gravity, high heat resistance, and excellent processability and chemical resistance.

Recently, a method of randomly copolymerizing propylene with ethylene or butene has been studied for the manufacture of injection-molded products requiring transparency. However, compared to conventional homopolypropylene, random copolymerized polypropylene has a problem in that crystallinity decreases as the content of butene, a comonomer in the polymer, increases, and as a result, flexural modulus, a physical property related to stiffness, decreases. .

On the other hand, catalysts for polypropylene polymerization can be largely classified into Ziegler-Natta catalysts and metallocene catalysts. In the case of the Ziegler-Natta catalyst, since it is a multi-site catalyst in which several active sites are mixed, It is characterized by a wide molecular weight distribution, and there is a problem that there is a limit to securing desired physical properties because the composition distribution of comonomers is not uniform. In particular, during copolymerization of propylene and ethylene by a bulk polymerization process, it is difficult to prepare a copolymer having a low melting point of 130° C. or less due to catalytic and process limitations.

On the other hand, the metallocene catalyst is composed of a combination of a main catalyst mainly composed of a transition metal compound and a cocatalyst composed of an organometallic compound mainly composed of aluminum. Such a catalyst is a single site catalyst as a homogeneous complex catalyst. A polymer with a narrow molecular weight distribution and a uniform comonomer composition distribution is obtained according to the characteristics of a single active point, and the tacticity of the polymer, copolymerization characteristics, molecular weight, It has properties that can change crystallinity, etc. However, even in the case of a conventional metallocene catalyst, when producing a propylene-ethylene copolymer having a low melting point of 125 ° C or less by bulk polymerization, the produced copolymer powder is sticky, fouling occurs in the reactor, etc. Production is not easy. there is a problem that is not

Accordingly, attempts have been made to improve product performance by blending two or more types of polypropylenes having different melting points depending on the use of the polypropylene. However, there are problems such as deterioration in product performance due to a decrease in blending efficiency and an additional process for reducing the size of pellets in the manufacturing process.

Therefore, it is required to develop a polymerization catalyst capable of improving the morphology of polymer powder by controlling the molecular structure of the polymer and improving the physical properties of the product by increasing polymerization stability.

The present invention is to provide a supported hybrid catalyst useful for producing polypropylene having two melting points having a temperature difference of at least a certain level with excellent physical properties, and a method for producing polypropylene using the same.

Accordingly, according to one embodiment of the present invention,

A first transition metal compound represented by Formula 1 below;

A second transition metal compound represented by Formula 2 below; and

A hybrid supported catalyst comprising a carrier is provided:

[Formula 1]

[Formula 2]

In Formulas 1 and 2,

A ₁ and A ₂ are each independently carbon, silicon or germanium;

M ₁ and M ₂ are each independently a group 14 element;

R ₁₁ to R ₁₄ are each independently C _1-20 alkyl;

R ₁₅ and R ₁₆ are each independently C _1-20 alkyl, C _1-20 alkoxy, or C _2-20 alkoxyalkyl;

R ₂₁ is C _1-20 alkyl; or C _6-20 aryl unsubstituted or substituted with C _1-20 alkyl;

R ₂₂ is C _6-20 aryl substituted with C _1-20 alkyl;

R ₂₃ and R ₂₄ are each independently C _1-20 alkyl;

X ₁₁ , X ₁₂ , X ₂₁ and X ₂₂ are each independently halogen.

In addition, according to another embodiment of the present invention, there is provided a method for producing polypropylene comprising the step of polymerizing propylene monomers while introducing hydrogen in the presence of the above hybrid supported catalyst.

In addition, according to another embodiment of the present invention, polypropylene produced by the above manufacturing method, having two melting points (Tm1 and Tm2), and a temperature difference (ΔTm) between the two melting points is greater than 5 ° C. to provide.

The supported hybrid catalyst according to the present invention includes a transition metal compound that is easy to prepare a high melting point polymer and a transition metal compound that is easy to prepare a low melting point polymer. It is possible to produce polypropylenes containing two melting points.

Accordingly, there is no risk of deterioration in product performance due to a decrease in blending efficiency during blending of heterogeneous polypropylenes having different melting points, and sinterability between beads can be improved during bead form molding, and high flexibility is achieved by improving shrinkage due to differences in melting points. (high soft) non-woven fabrics can be manufactured.

Terms used in this specification are only used to describe exemplary embodiments, and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, terms such as "comprise", "comprise" or "having" are intended to indicate that there is an embodied feature, step, component, or combination thereof, but one or more other features or steps; It should be understood that the presence or addition of components, or combinations thereof, is not previously excluded.

Since the invention can have various changes and various forms, specific embodiments will be exemplified and described in detail below. However, it should be understood that this is not intended to limit the invention to a particular disclosed form, and includes all modifications, equivalents, and substitutes included in the spirit and scope of the invention.

Hereinafter, hybrid supported catalysts according to specific embodiments of the invention, methods for producing polypropylene using the same, and polypropylene prepared therefrom will be described.

A hybrid supported catalyst according to an embodiment of the present invention includes a first transition metal compound represented by Formula 1 below; A second transition metal compound represented by Formula 2 below; and a carrier.

[Formula 1]

[Formula 2]

In Formulas 1 and 2,

A ₁ and A ₂ are each independently carbon, silicon or germanium;

M ₁ and M ₂ are each independently a group 14 element;

R ₁₁ to R ₁₄ are each independently C _1-20 alkyl;

R ₁₅ and R ₁₆ are each independently C _1-20 alkyl, C _1-20 alkoxy, or C _2-20 alkoxyalkyl;

R ₂₁ is C _1-20 alkyl; or C _6-20 aryl unsubstituted or substituted with C _1-20 alkyl;

R ₂₂ is C _6-20 aryl substituted with C _1-20 alkyl;

R ₂₃ and R ₂₄ are each independently C _1-20 alkyl;

X ₁₁ , X ₁₂ , X ₂₁ and X ₂₂ are each independently halogen.

In the transition metal compound according to the present invention, the substituents of Chemical Formulas 1 and 2 are described in more detail as follows.

The halogen may be fluorine (F), chlorine (Cl), bromine (Br) or iodine (I).

C _1-20 alkyl can be straight chain, branched chain or cyclic alkyl. Specifically, C _1-20 alkyl is C _1-20 straight-chain alkyl, C _1-10 straight-chain alkyl, C _1-5 straight-chain alkyl, C _3-20 branched or cyclic alkyl, C _3-15 branched or cyclic alkyl, or C _3-10 branched or cyclic alkyl. More specifically, C _1-20 alkyl can be methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, tert-butyl, n-pentyl, iso-pentyl or cyclohexyl, and the like.

C _2-20 alkenyl can be straight chain, branched chain or cyclic alkenyl. Specifically, C _2-20 alkenyl is C _2-20 straight chain alkenyl, C _2-10 straight chain alkenyl, C _2-5 straight chain alkenyl, C _3-20 branched chain alkenyl, C _3-15 branched chain alkenyl kenyl, C _3-10 branched chain alkenyl, C _5-20 cyclic alkenyl or C _5-10 cyclic alkenyl. More specifically, C _2-20 alkenyl may be ethenyl, propenyl, butenyl, pentenyl or cyclohexenyl and the like.

C _6-20 aryl can mean a monocyclic, bicyclic or tricyclic aromatic hydrocarbon. Specifically, C _6-20 aryl may be a phenyl group, a naphthyl group, or an anthracenyl group.

C _7-20 alkylaryl may mean a substituent in which one or more hydrogens of aryl are substituted with alkyl. Specifically, C _7-20 alkylaryl may be methylphenyl, ethylphenyl, n-propylphenyl, iso-propylphenyl, n-butylphenyl, iso-butylphenyl, tert-butylphenyl or cyclohexylphenyl.

C _7-20 arylalkyl may mean a substituent in which one or more hydrogens of alkyl are substituted by aryl. Specifically, C _7-20 arylalkyl may be a benzyl group, phenylpropyl, or phenylhexyl.

C _1-20 alkoxy can be straight chain, branched chain or cyclic alkoxy. Specifically, examples of C _1-20 alkoxy include methoxy, ethoxy, n-butoxy, tert-butoxy, phenyloxy, cyclohexyloxy, and the like, but are not limited thereto.

C _2-20 alkoxyalkyl may mean a substituent in which one or more hydrogens of alkyl are substituted with alkoxy. Specifically, as C _2-20 alkoxyalkyl, methoxymethyl, ethoxymethyl, methoxyethyl, ethoxyethyl, butoxymethyl, butoxyethyl, butoxypropyl, butoxybutyl, butoxyheptyl, butoxy Hexyl, etc. may be mentioned, but is not limited thereto.

The hybrid supported catalyst according to the present invention is one in which at least one type of first transition metal compound represented by Formula 1 and at least one type of second transition metal compound represented by Formula 2 are mixed-supported on a carrier. The first transition metal compound represented by Formula 2 contributes to the production of a polymer with a high melting point due to a characteristic structure in which a phenyl group capable of supplying sufficient electrons to indacene is introduced, and the second transition metal compound represented by Formula 2 is a different kind of Due to the pseudo C2-Symmetric characteristic structure introduced with asymmetric indenes, it contributes to the production of low-melting polymers.

Specifically, the first transition metal compound represented by Chemical Formula 1 has a structure of two indacenes above and below and a silane bridge connecting them. While the general ligand structure of a metallocene compound is indene, the first transition metal compound in the present invention includes an indacene structure in which a pentagonal saturated ring compound is fused to indene. Olefin polymers exhibiting a wider molecular weight distribution than indene ligands can be polymerized by such indacene-containing ligands.

In addition, sufficient electrons can be supplied by including a phenyl group in which the 2-position of indacene is substituted with a methyl group and the 3- and 5-positions are disubstituted with alkyl groups (R ₁₁ and R ₁₂ , or R ₁₃ and R ₁₄ ), respectively. More excellent catalytic activity can be exhibited by the inductive effect that can occur.

In addition, since two indacenes are linked by a bridge group, they can have high structural stability and exhibit high polymerization activity even when supported on a carrier.

More specifically, R ₁₁ to R ₁₄ in Formula 1 may each independently be a C _1-10 alkyl group, and more specifically, may be a C _3-6 branched chain alkyl such as tert-butyl.

Also, in Chemical Formula 1, X ₁₁ and X ₁₂ may each independently represent chloro (Cl).

Also, in Chemical Formula 1, A ₁ may be silicon, and M ₁ may be zirconium or hafnium.

In addition, R ₁₅ and R ₁₆ substituents of A ₁ may each independently be C _1-10 alkyl or C _2-20 alkoxyalkyl, and more specifically, a C _1-4 straight-chain alkyl group or a C _3-6 branched chain. It may be a C _3-10 alkyl group substituted with a chain alkoxy group. More specifically, R ₁₅ and R ₁₆ may each independently be methyl, ethyl, n-propyl, iso-propyl, n-butyl, tert-butyl, or tert-butoxy hexyl.

Specific examples of the transition metal compound of Chemical Formula 1 include compounds represented by the following structural formula, and any one or a mixture of two or more of them may be used.

In addition, in the hybrid supported catalyst according to an embodiment of the present invention, the second transition metal compound represented by Chemical Formula 2 has a C2-Symmetric structure for maintaining isotacticity in the polymerization of polypropylene and contains both indenes. It has a structure of Pseudo C2-Symmetric that can implement each feature. Accordingly, since it can have various characteristics or selective advantages of the other two indenes, it can exhibit better catalytic activity.

Specifically, the second transition metal compound is a bridge group connecting two ligands including an indenyl group, and includes a divalent functional group A ₂ substituted with an alkyl group having 1 or more carbon atoms (R ₂₃ and R ₂₄ ), thereby reducing the atomic size. As the solubility angle increases, the access of the monomer becomes easier, and thus more excellent catalytic activity can be exhibited.

In addition, one of the two indenyl groups, which are ligands in the second transition metal compound, has only the 3-position (R ₂₁ ) substituted, and the other indenyl group is asymmetric by substituting the 2- and 4-positions with a methyl group and R ₂₂ , respectively. have a negative structure. Accordingly, it is possible to exhibit the effect of lowering the melting point by adjusting the tacticity in the molecular structure of polypropylene.

In addition, in the case of an indenyl ligand in which only the 3-position is substituted, the resulting polymer may exhibit a narrower molecular weight distribution compared to the case where the other positions are substituted. As the substituent at position 3, R ₂₁ is C _1-20 alkyl; or C _6-20 aryl unsubstituted or substituted with C _1-20 alkyl, more specifically C _3-10 straight-chain alkyl such as n-propyl, n-butyl; C _3-10 branched chain alkyl such as isopropyl; phenyl; or phenyl substituted with C _3-6 branched chain alkyl such as t-butylphenyl. When substituted with these substituents, higher catalytic activity can be exhibited.

In addition, in the case of an indenyl ligand in which positions 2 and 4 are respectively substituted, position 2 may include methyl, and R ₂₂ at position 4 may include C _6-20 aryl substituted with C _1-20 alkyl. . In this way, when each position is substituted, more excellent catalytic activity can be exhibited by an inductive effect capable of supplying sufficient electrons.

More specifically, R ₂₂ in Formula 2 may be a phenyl group substituted with a C _3-6 branched chain alkyl group such as tert-butyl phenyl. In addition, the substitution position of the alkyl group for the phenyl group may be position 4 corresponding to the position of R ₂₂ bonded to the indenyl group and the position para.

In addition, the second transition metal compound may include a Group 14 metal such as zirconium (Zr) and hafnium (Hf) as the central metal (M ₂ ), and among them, when including zirconium (Zr), such as Hf Compared to other Group 14 elements, it has more orbitals capable of accepting electrons, so it can easily bind with monomers with higher affinity, and as a result, it can exhibit better catalytic activity improvement effect.

Also, in Chemical Formula 2, X ₂₁ and X ₂₂ may each independently represent chloro.

In Formula 2, A ₂ may be silicon (Si), and substituents R ₂₃ and R ₂₄ of A ₂ are identical to each other in terms of improving loading efficiency by increasing solubility, and C _1-10 alkyl , more specifically C _1-4 straight chain alkyl, more specifically each may be a methyl group. In this way, by having the same alkyl group as a substituent for A ₂ of the bridge group, solubility is excellent when preparing a supported catalyst, and thus improved supported reactivity can be exhibited.

Representative examples of the second transition metal compound represented by Formula 2 include compounds having the following structures, and any one or a mixture of two or more of them may be used:

The first and second transition metal compounds may be prepared according to known organic compound synthesis methods, and detailed preparation methods are specifically described in Preparation Examples to be described later.

Meanwhile, the supported hybrid catalyst according to an embodiment of the present invention includes the first transition metal compound represented by Formula 1 and the second transition metal compound represented by Formula 2 in a molar ratio of 6:1 to 1:6. do. When the first and second transition metal compounds are included in the mixing molar ratio, appropriate catalytic activity may be exhibited and it may be more advantageous to achieve balanced physical properties of polypropylene. Out of the molar ratio range of the first and second transition metal compounds, the first transition metal compound is included in an excess of more than 6 molar ratio with respect to 1 mol of the second transition metal compound, or the second transition to 1 mol of the first transition metal compound When the metal compound is included in excess in a molar ratio of more than 6, there is a concern that the effect of improving physical properties due to the difference in the degree of characteristic expression of the polymer prepared from each transition metal compound may be reduced. More specifically, the first and second transition metal compounds may be included in a molar ratio of 3:1 to 1:3, and in this case, better catalytic activity can be implemented while maintaining excellent hydrogen reactivity.

In addition, the first and second transition metal compounds can be stably supported on a carrier due to the above-described structural characteristics, and as a result, the polypropylene produced has excellent morphology and physical properties, and conventional slurry polymerization or bulk polymerization, It can be used suitably for a gas phase polymerization process.

Specifically, as the carrier, a carrier having a highly reactive hydroxyl group, silanol group, or siloxane group on the surface may be used, and for this purpose, a carrier modified by calcination or having moisture removed from the surface by drying may be used. can be used For example, silica prepared by calcining silica gel, silica such as silica dried at high temperature, silica-alumina, and silica-magnesia may be used, and these are usually Na ₂ O, K ₂ CO ₃ , BaSO ₄ , and Mg ( oxides such as NO ₃ ) ₂ , carbonates, sulfates, and nitrate components.

When calcining or drying the carrier, the temperature may be 200 to 600 °C, or 250 to 600 °C. When the calcination or drying temperature of the carrier is lower than 200° C., there is too much moisture remaining in the carrier, and there is a concern that the surface moisture and the promoter may react, and due to the hydroxyl group present in excess, the promoter support The oil rate can be relatively high, but this requires a large amount of cocatalyst. In addition, when the drying or calcination temperature is too high, exceeding 600 ° C, the pores on the surface of the carrier are combined and the surface area is reduced, and many hydroxyl or silanol groups are lost on the surface, leaving only siloxane, which is the site of reaction with the cocatalyst. is likely to decrease.

For example, the amount of hydroxy groups on the surface of the carrier may be 0.1 to 10 mmol/g, or 0.5 to 5 mmol/g. The amount of hydroxyl groups on the surface of the carrier can be controlled by the manufacturing method and conditions of the carrier or drying conditions, such as temperature, time, vacuum or spray drying. If the amount of the hydroxy group is too low, there are few reaction sites with the cocatalyst, and if the amount is too large, it may be caused by moisture in addition to the hydroxy group present on the surface of the carrier particle.

Among the above carriers, in the case of silica, since the functional group of the silica carrier and the transition metal compound are chemically bonded and supported, there is almost no catalyst released from the surface of the carrier in the propylene polymerization process, and as a result, polypropylene can be obtained by slurry or gas phase polymerization. When manufacturing, it is possible to minimize fouling, in which the walls of the reactor or polymer particles are entangled with each other.

In addition, when the first and second transition metal compounds are supported on a carrier, the total amount of the first and second transition metal compounds is 0.05 mmol or more, or 0.1 mmol or more based on the weight of the carrier, for example, 1 g of silica. And, it may be supported in a content range of 10 mmol or less, or 0.5 mmol or less. When supported in the above content range, appropriate supported catalyst activity may be exhibited, which may be advantageous in terms of maintaining the activity of the catalyst and economic efficiency.

In addition, the supported hybrid catalyst according to an embodiment of the present invention may further include a cocatalyst in terms of improving high activity and process stability, in addition to the first and second transition metal compounds and the carrier. The cocatalyst may include one or more of the compounds represented by Formula 3, Formula 4, or Formula 5 below.

[Formula 3]

-[Al(R ₃₁ )-O] _m -

In Formula 3,

R ₃₁ may be the same as or different from each other, and each independently halogen; C _1-20 hydrocarbon; or C _1-20 hydrocarbon substituted with halogen;

m is an integer of 2 or greater;

[Formula 4]

J(R ₃₂ ) ₃

In Formula 4,

R ₃₂ may be the same as or different from each other, and each independently halogen; C _1-20 hydrocarbon; or C _1-20 hydrocarbon substituted with halogen;

J is aluminum or boron;

[Formula 5]

[EH] ⁺ [ZQ ₄ ] ^- or [E] ⁺ [ZQ ₄ ] ^-

In Formula 5,

E is a neutral or cationic Lewis base;

H is a hydrogen atom;

Z is a Group 13 element;

Q may be the same as or different from each other, and each independently represents _a C _{6-20 aryl group or C 1-20} unsubstituted or substituted with one or more hydrogen atoms halogen, C _1-20 hydrocarbon, alkoxy or phenoxy. is an alkyl group.

Examples of the compound represented by Formula 3 include aluminoxane-based compounds such as methylaluminoxane, ethylaluminoxane, isobutylaluminoxane, or butylaluminoxane, and any one or a mixture of two or more of these may be used. .

Examples of the compound represented by Formula 4 include trimethylaluminum, triethylaluminium, triisobutylaluminum, tripropylaluminum, tributylaluminum, dimethylchloroaluminum, triisopropylaluminium, tri-s-butylaluminum, and tricyclopentylaluminum. , tripentyl aluminum, triisopentyl aluminum, trihexyl aluminum, trioctyl aluminum, ethyl dimethyl aluminum, methyl diethyl aluminum, triphenyl aluminum, tri-p-tolyl aluminum, dimethyl aluminum methoxide, dimethyl aluminum ethoxide, trimethyl Boron, triethylboron, triisobutylboron, tripropylboron, tributylboron, etc. are included, and more specifically, it may be selected from trimethylaluminum, triethylaluminum, and triisobutylaluminum.

In addition, examples of the compound represented by Formula 5 include triethylammonium tetraphenylboron, tributylammonium tetraphenylboron, trimethylammonium tetraphenylboron, tripropylammonium tetraphenylboron, and trimethylammonium tetraphenylboron (p- Tolyl) boron, trimethylammonium tetra(o,p-dimethylphenyl)boron, tributylammoniumtetra(p-trifluoromethylphenyl)boron, trimethylammoniumtetra(p-trifluoromethylphenyl)boron, tributylammonium Um tetrapentafluorophenyl boron, N,N-diethylanilinium tetraphenyl boron, N,N-diethylanilinium tetrapentafluorophenyl boron, diethylammonium tetrapentafluorophenyl boron, triphenyl Phosphonium tetraphenylboron, trimethylphosphonium tetraphenylboron, triethylammonium tetraphenyl aluminum, tributylammonium tetraphenyl aluminum, trimethylammonium tetraphenyl aluminum, tripropylammonium tetraphenyl aluminum, 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 tetrapentafluorophenyl aluminum, N,N-diethylanilinium tetraphenyl aluminum, N,N-diethylanilinium tetrapentafluorophenyl aluminum , diethylammonium tetrapentatetraphenyl aluminum, triphenylphosphonium tetraphenyl aluminum, trimethylphosphonium tetraphenyl aluminum, tripropylammonium tetra(p-tolyl) boron, triethylammonium tetra(o,p-dimethylphenyl) ) boron, tributylammonium tetra(p-trifluoromethylphenyl)boron, triphenylcarboniumtetra(p-trifluoromethylphenyl)boron, or triphenylcarbonium tetrapentafluorophenylboron. Any one or a mixture of two or more of these may be used.

Considering that among the cocatalysts, when used in combination with the first and second transition metal compounds, more excellent catalytic activity can be exhibited, the cocatalyst is the compound of Formula 3, more specifically, methylaluminoxane It may be an alkyl aluminoxane-based compound such as. The alkylaluminoxane-based cocatalyst improves activity by acting as a scavenger for hydroxyl groups present on the surface of a carrier as well as activating transition metal compounds.

The cocatalyst may be supported in an amount of 1 mmol or more, or 5 mmol or more, and 30 mmol or less, or 20 mmol or less, based on the weight of the carrier, for example, 1 g of silica. When included in the above content range, it is possible to sufficiently obtain the effect of reducing the generation of fine powder together with the effect of improving the catalytic activity according to the use of the cocatalyst.

The hybrid supported catalyst may be prepared by supporting the first and second transition metal compounds on the support, and when the supported hybrid catalyst further includes the cocatalyst, the first and second transition metal compounds The cocatalyst may be supported before or after the support.

For example, when the hybrid supported catalyst further includes a cocatalyst, supporting the cocatalyst compound; supporting the first transition metal compound on the support on which the cocatalyst is supported; and supporting the second transition metal compound on the carrier on which the cocatalyst and the first transition metal compound are supported. The structure of the supported catalyst determined according to the supporting/treatment sequence may affect the catalyst activity and process stability during polymer production. As described above, after supporting the cocatalyst, the first and second transition metal compounds may be sequentially supported. In this case, the structure of the prepared supported catalyst is stable, so that excellent process stability can be implemented with high catalytic activity.

As described above, the supported hybrid catalyst according to one embodiment of the present invention includes heterogeneous transition metal compounds that are easy to prepare polymers having different melting points, so that the polypropylene produced has two melting points, and further polymerization By controlling the conditions, the difference between the two melting points has a certain level or more, so that more excellent sinterability and shrinkage improvement effects can be exhibited.

Accordingly, according to another embodiment of the present invention, a method for producing polypropylene using the above hybrid supported catalyst and a polypropylene prepared according to the method are provided.

Specifically, the method for producing polypropylene includes the step of polymerizing propylene monomers while introducing hydrogen in the presence of the above-described hybrid supported catalyst, or copolymerizing propylene monomers and ethylene monomers, Propylene or random copolymers of ethylene and propylene can be prepared.

Depending on the polymerization method, the hybrid supported catalyst may be used in a slurry state in a solvent, may be used in a diluted state, or may be used in the form of a mud catalyst mixed with a mixture of oil and grease.

When the hybrid supported catalyst is used in a slurry state or diluted in a solvent, the solvent is an aliphatic hydrocarbon solvent having 5 to 12 carbon atoms suitable for polymerization of propylene monomers, such as pentane, hexane, heptane, and nonane. , decane, and isomers thereof, aromatic hydrocarbon solvents such as toluene and benzene, or hydrocarbon solvents substituted with chlorine atoms such as dichloromethane and chlorobenzene, and any one or a mixture of two or more of these may be used. In this case, the catalyst composition may further include the above solvent, and a small amount of water or air that may act as a catalyst poison may be removed by treating the solvent with a small amount of alkylaluminum before use.

In addition, the hydrogen may be added in an amount of 30 to 800 ppm based on the total weight of the monomers for producing polypropylene, specifically, the total weight of the monomers including propylene and optionally ethylene. As described above, process stability can be improved because hydrogen is introduced in a much reduced amount compared to the prior art. In addition, the physical properties of the polypropylene, particularly the molecular weight distribution and fluidity, can be adjusted within a desired range by adjusting the amount of hydrogen gas added. In the present invention, by adding hydrogen in the above-described content range, distribution, and a melt index of 5 to 40 g/10 min.

In addition, the polymerization process may be carried out as a continuous polymerization process, for example, a continuous solution polymerization process, a bulk polymerization process, a suspension polymerization process, a slurry polymerization process or an emulsion polymerization process, etc. Various polymerization processes known as polymerization of olefin monomers this may be employed. In particular, a continuous bulk-slurry polymerization process may be preferred in terms of obtaining a uniform molecular weight distribution and commercial production of the product.

In addition, the polymerization reaction may be carried out at a temperature of 40 ° C or higher, or 60 ° C or higher, 110 ° C or lower or 100 ° C or lower, and when the pressure conditions are further controlled, 1 bar or higher, or 5 bar or higher, and 15 bar or less, or under a pressure of 10 bar or less.

In addition, trialkylaluminum such as triisobutylaluminum (TIBAL) may be selectively further added during the polymerization reaction.

If moisture or impurities are present in the polymerization reactor, a portion of the catalyst is decomposed. Since the trialkylaluminum serves as a scavenger to preliminarily capture moisture or impurities present in the reactor or moisture contained in the monomers, The activity of the catalyst used in the production can be maximized, and as a result, homo-polypropylene having excellent physical properties, in particular, a narrow molecular weight distribution can be more efficiently produced. Specifically, in the trialkyl aluminum, alkyl is as defined above, specifically C _1-20 alkyl, more specifically C _1-6 straight-chain or C _3-6 such as methyl, ethyl, isobutyl, etc. may be a branched chain alkyl of

According to the above production method, polypropylene exhibiting two melting points can be produced by using the above-described hybrid supported catalyst, and also produced with a reduced amount of hydrogen input during polymerization due to the excellent hydrogen reactivity of the hybrid supported catalyst Polypropylene has physical properties that are equivalent to or better than those of conventional catalysts.

Specifically, the polypropylene produced by the production method using the hybrid supported catalyst has two melting points (Tm1 and Tm2), and a temperature difference (ΔTm) between the two melting points is greater than 5 °C.

Since the polymer produced through a single polymerization process has two melting points, it is possible to solve the problem of deterioration in product performance due to a decrease in blending efficiency when polypropylenes having different melting points are conventionally blended. In addition, there is a problem such as reduced productivity due to issues such as reactor fouling during the production of conventional low-melting polypropylene, but in the present invention, these problems are solved through the above manufacturing process, and product performance is improved based on polymerization stability. can be further improved. In addition, when the temperature difference between the two melting points is 5 ° C or less, the improvement effect of the polymer properties (sinterability between beads, shrinkage) according to the inclusion of the two melting points is insignificant or there is a concern about reducing the effect. As described above, the two melting points are 5 ° C By having a difference of excess, it is possible to have balanced physical properties. More specifically, it may be above 7°C or above 8°C, and below 20°C or below 15°C or below 12°C.

More specifically, the polypropylene satisfies the aforementioned melting point conditions, has a first melting point (Tm1) of 130 to 160 °C, or 130 to 158 °C, and a second melting point (Tm2) of 120 to 150 °C, or 120 °C. to 147°C. By having the first and second melting points in the above range, it is possible to improve the sinterability between the beads during bead form molding. In addition, it is possible to manufacture a highly soft nonwoven fabric having twist properties of fiber by improving shrinkage due to the difference in melting point.

Meanwhile, in the present invention, the melting point of the polypropylene can be measured using a differential scanning calorimeter (DSC). Specifically, after increasing the temperature of polypropylene to 200 ° C, maintaining it at that temperature for 5 minutes, then lowering it to 30 ° C, and then increasing the temperature again to reach the peak of the DSC (Differential Scanning Calorimeter, manufactured by TA) curve. It can be measured by taking as the melting point. At this time, the rate of temperature rise and fall is 10 °C/min, respectively, and the melting point is the result measured in the section where the second temperature rises.

In addition, the polypropylene has a melt index (MI) of 5 measured at 230 ° C. under a load of 2.16 kg according to ASTM D1238 through the use of the above-described hybrid supported catalyst and control of polymerization conditions, in particular, hydrogen input during the polymerization reaction. g/10 min or more, or 10 g/10 min or more, and may be 40 g/10 min or less, or 30 g/10 min or less. Accordingly, excellent processability can be exhibited despite having a narrow molecular weight distribution described later.

In addition, the polypropylene has a molecular weight distribution (MWD = Mw/Mn) of 2.5 or more, or 3 or more, and 5 or less or 4 or less under the condition of satisfying the above melt index range. As such, it has a narrow molecular weight distribution compared to polypropylene prepared using a conventional hybrid supported catalyst, and thus, mechanical properties such as tensile strength can be improved.

On the other hand, in the present invention, the molecular weight distribution (MWD) of polypropylene can be measured using gel permeation chromatography (GPC), and MWD is the weight average molecular weight (Mw) and number average molecular weight (Mn) measured Then, it can be determined by the ratio of the weight average molecular weight to the number average molecular weight (Mw/Mn). Specifically, it can be measured using a Waters PL-GPC220 instrument using a Polymer Laboratories PLgel MIX-B 300 mm long column. At this time, the evaluation temperature is 160°C, 1,2,4-trichlorobenzene is used as a solvent, and the flow rate is 1 mL/min. In addition, the sample is prepared at a concentration of 10mg/10mL and then supplied in an amount of 200μL. A calibration curve formed using polystyrene standards is used to derive the values of Mw and Mn. At this time, nine kinds of molecular weight (g / mol) of the polystyrene standard were used: 2,000 / 10,000 / 30,000 / 70,000 / 200,000 / 700,000 / 2,000,000 / 4,000,000 / 10,000,000.

In addition, the polypropylene satisfies the above-described characteristics, and at the same time, xylene solubles (Xs) is 1.0% by weight or less, and exhibits high tacticity.

In the present invention, the xylene soluble content is obtained by dissolving polypropylene in xylene and then cooling it, crystallizing the insoluble portion from the resulting cooling solution, and measuring the content (wt%) of the soluble polymer in the determined cooled xylene. Accordingly, the xylene soluble content includes polymer chains of low stereoregularity. Accordingly, it can be seen that the lower the xylene soluble content, the higher the stereoregularity of the polymer. Polypropylene according to one embodiment of the present invention exhibits a low xylene soluble content of 1.0% by weight or less, has high stereoregularity, and as a result, can exhibit excellent stiffness and flexural modulus.

More specifically, the xylene soluble content of the polypropylene is 1.0 wt% or less, or 0.9 wt% or less, or 0.8 wt% or less, or 0.7 wt% or less, and 0.1 wt% or more, or 0.2 wt% or more, or 0.3 wt% or less % or more, or 0.4 wt% or more, or 0.5 wt% or more.

In the present invention, the xylene soluble content of polypropylene is specifically prepared by adding xylene to a polypropylene sample, heating it at 135 ° C. for 1 hour, cooling it for 30 minutes, and then pre-treating it. The base line of RI, DP, and IP is stabilized by flowing xylene for 4 hours at a flow rate of mL/min, and then measuring by entering the concentration and injection amount of the pretreated sample and calculating the peak area can do.

More specifically, the polypropylene may be homopropylene, the homopropylene has two melting points (Tm1 and Tm2), and the temperature difference (ΔTm) between the two melting points is greater than 5 ° C, or greater than 7 ° C, or 7 °C above 20 °C, Tm1 is 152 to 158 °C, Tm2 is 143 to 147 °C, MI is 10 g/10 min or more, or 15 g/10 min or more, and 30 g/10 min or less, or 27 g/10 min Hereinafter, the MWD may be 2.5 or more, or 3 or more, 5 or less, or 4 or less, and the xylene soluble content may be 1% by weight or less, or 0.7% by weight or less.

In addition, the polypropylene may be a propylene-ethylene random copolymer, and the propylene-ethylene random copolymer has two melting points (Tm1 and Tm2), and the temperature difference (ΔTm) between the two melting points is greater than 5 ° C., or 7 greater than °C, or greater than 7 °C and up to 20 °C, Tm1 is 130 to 135 °C, Tm2 is 120 to 125 °C, MI is 5 g/10 min or more, or 10 g/10 min or more, and 25 g/10 min or less; or 15 g/10 min or less, MWD of 2.5 or more, or 3.5 or more, 5 or less or 4 or less, and a xylene soluble content of 1% by weight or less, or 0.8% by weight or less.

Accordingly, polypropylene according to one embodiment of the present invention can be used for various purposes requiring the above physical properties, and is particularly useful for bead form molding requiring excellent sintering properties or manufacturing highly flexible nonwoven fabrics requiring excellent shrinkage properties. .

Hereinafter, a preferred embodiment is presented to aid understanding of the present invention. However, the following examples are only provided to more easily understand the present invention, and the content of the present invention is not limited thereby.

<Synthesis Example of First Transition Metal Compound>

Synthesis Example 1

dimethylsilanediyl ( Bis(4-(3,5-di-tert-butylphenyl) -2- methyl -1,5,6,7- tetrahydro -s-indasen-1-yl)zirconium dichloride ( dimethylsilanediyl (bis(4-(3,5- di - tert Preparation of -butylphenyl) -2-methyl-1,5,6,7-tetrahydro-s-indacen-1-yl) zirconium dichloride (precursor A)

(A)

(A)

1-1> Synthesis of Ligand Compound

5 g of indacene was added to the reactor, dried under reduced pressure for 30 minutes, and 43 mL of toluene and 4.3 mL of THF were added and stirred to completely dissolve the mixture. After cooling the reactor to -25 °C, n-BuLi (2.5 M, 5.9 mL) was slowly added dropwise while stirring. After stirring at 25° C. for 12 hours, 18.0 mg of CuCN was added as a slurry of toluene in a small amount, followed by dimethylsilane (7.25 mmol) after 30 minutes. After stirring at room temperature for 12 hours, water was added and stirred. After the reactor was allowed to stand, the water layer was separated. The aqueous layer and toluene were reintroduced into the reactor, stirred and allowed to stand for 5 minutes, and then the aqueous layer was separated and removed. The organic layer was dehydrated with MgSO ₄ , filtered again, introduced into a reactor, dried, and dimethylsilanediyl (bis(4-(3,5-di-tert-butylphenyl)-2-methyl-1,5,6 ,7-tetrahydro-s-indacen-1-yl) was obtained in a yield of 20%.

1H NMR (500MHz, CDCl ₃ ): 0.21 (s, 6H), 1.32 (s, 36H), 1.79(s, 6H), 1.95(m, 4H), 2.80-2.85(m, 8H), 7.73(s, 2H), 7.42(s, 2H), 7.55(s, 2H), 7.73(s, 4H)

1-2> Synthesis of transition metal compounds

21 mL of toluene and 2.1 mL of Et ₂ O were injected into the dried ligand and stirred. After cooling to -25 °C, n-BuLi (2.5 M, 5.9 mL) was slowly added dropwise and stirred. After stirring at 25 °C for 12 hours and cooling to -20 °C, ZrCl ₄ (7 mmol) was dissolved in toluene and added thereto. After stirring at 25 °C for 12 hours, all solvents were dried. After filtering and drying using DCM, recrystallization was performed using DCM. The title compound in the form of a yellow powder (only racemic) was obtained in a yield of 20%.

Synthesis Example 2

dimethylsilanediyl ( bis (4-(3,5-di-tert-butylphenyl)-2-methyl-1,5,6,7-tetrahydro-s-indacen-1-yl) hafnium dichloride Manufacturing (precursor B)

(B)

(B)

2-1> Synthesis of Ligand Compound

In the same manner as 1-1 of Synthesis Example 1, dimethylsilanediyl (bis(4-(3,5-di-tert-butylphenyl)-2-methyl-1,5,6,7-tetrahydro-s -indacen-1-yl) to obtain a ligand compound.

2-2> Synthesis of transition metal compounds

21 mL of toluene and 2.1 mL of Et ₂ O were injected into the dried ligand and stirred. After cooling to -25 °C, n-BuLi (2.5 M, 5.9 mL) was slowly added dropwise and stirred. After stirring at 25 °C for 12 hours and cooling to -20 °C, HfCl ₄ (7 mmol) was dissolved in toluene and added thereto. After stirring at 25 °C for 12 hours, all solvents were dried. After filtering and drying using DCM, recrystallization was performed using DCM. The title compound in the form of a yellow powder (only racemic) was obtained in a yield of 15%.

Synthesis Example 3

6-( tert - butoxy ) hexyl ) methylsilanediyl ( bis (4-(3,5-di-tert-butylphenyl)-2-methyl-1,5,6,7-tetrahydro-s-indacen-1-yl) zirconium dichloride Manufacturing (precursor C)

(C)

(C)

3-1> Synthesis of Ligand Compound

After adding 5g of indacene to the reactor, the mixture was dried under reduced pressure for 30 minutes, and 43 mL of toluene and 4.3 mL of THF were added and stirred to completely dissolve the mixture. After cooling the reactor to -25 °C, n-BuLi (2.5 M, 5.9 mL) was slowly added dropwise while stirring. After stirring at 25° C. for 12 hours, 18.0 mg of CuCN was added in a small amount of toluene slurry, and 6-tert-butoxyhexylmethylsilane (7.25 mmol) was then added after 30 minutes. After stirring at room temperature for 12 hours, water was added and stirred. After the reactor was allowed to stand, the water layer was separated. The aqueous layer and toluene were reintroduced into the reactor, stirred and allowed to stand for 5 minutes, and then the aqueous layer was separated and removed. The organic layer was dehydrated with MgSO ₄ , filtered again, put into a reactor, dried, and 6-(tert-butoxy)hexyl)methylsilanediyl (bis(4-(3,5-di-tert-butylphenyl)) A ligand compound of -2-methyl-1,5,6,7-tetrahydro-s-indacen-1-yl) was obtained in a yield of 8%.

1H NMR (500MHz, CDCl ₃ ): 0.21(s, 3H), 0.60(t, 2H), 1.13(s, 9H), 1.23-1.30(m, 4H), 1.32 (s, 36H), 1.79(s, 6H), 1.95(m, 4H), 3.35(t, 2H), 6.36(s,2H), 7.42(s,2H), 7.55(s, 2H), 7.73(s, 4H)

3-2> Synthesis of transition metal compounds

21 mL of toluene and 2.1 mL of Et ₂ O were injected into the dried ligand and stirred. After cooling to -25 °C, n-BuLi (2.5 M, 5.9 mL) was slowly added dropwise and stirred. After stirring at 25 °C for 12 hours and cooling to -20 °C, ZrCl ₄ (7 mmol) was dissolved in toluene and added thereto. After stirring at 25 °C for 12 hours, all solvents were dried. After filtering and drying using DCM, recrystallization was performed using DCM. The title compound in the form of a yellow powder (only racemic) was obtained in a yield of 14%.

Synthesis Example 4

6-( tert - butoxy ) hexyl ) methylsilanediyl ( bis (4-(3,5-di-tert-butylphenyl)-2-methyl-1,5,6,7-tetrahydro-s-indacen-1-yl) hafnium dichloride Manufacturing (precursor D)

(D)

(D)

4-1> Synthesis of Ligand Compound

6-(tert-butoxy)hexyl)methylsilanediyl (bis(4-(3,5-di-tert-butylphenyl)-2-methyl-1, A ligand compound of 5,6,7-tetrahydro-s-indacen-1-yl) was obtained.

4-2> Synthesis of transition metal compounds

21 mL of toluene and 2.1 mL of Et ₂ O were injected into the dried ligand and stirred. After cooling to -25 °C, n-BuLi (2.5 M, 5.9 mL) was slowly added dropwise and stirred. After stirring at 25 °C for 12 hours and cooling to -20 °C, HfCl ₄ (7 mmol) was dissolved in toluene and added thereto. After stirring at 25 °C for 12 hours, all solvents were dried. After filtering and drying using DCM, recrystallization was performed using DCM. The title compound in the form of a yellow powder (only racemic) was obtained in a yield of 26%.

<Synthesis Example of Second Transition Metal Compound>

Synthesis Example 5

Dimethylsilanediyl (3-phenyl-1H-inden-1-yl) (2- methyl -4-(4- tert - Butylphenyl )-1H- inden -1-day) zirconium dichloride Manufacturing (precursor E)

(E)

(E)

5-1> Synthesis of Ligand Compound

After dissolving 1 equivalent (1eq) of 3-phenyl-1H-indene in a mixed solution of toluene/THF (10/1 volume ratio, 0.5M), n-BuLi (1.05 After slowly adding eq) dropwise, the mixture was stirred at room temperature for 3 hours. Dichloro dimethyl silane (1.05 eq) was added to the resulting reaction mixture at -10 ° C, followed by stirring at room temperature overnight to prepare a mono-Si solution.

In another reactor, 2-Me-4-(4-tBuPh)Indene (2-Me-4-(4-tBuPh)Indene) (1 eq) was added to a mixed solution of toluene/THF (5/1 volume ratio, 0.7 M), n-BuLi (1.05 eq) was slowly added dropwise at -25°C, followed by stirring at room temperature for 3 hours. After adding CuCN (2 mol%) to the resulting reaction mixture and stirring for 30 minutes, the mono-Si solution was added thereto. Thereafter, the mixture was stirred at room temperature overnight, worked up using water, and dried to obtain a ligand.

5-2> Synthesis of transition metal compounds

Dissolve the ligand prepared above in a mixed solution of toluene/diethyl ether (2/1 volume ratio, 0.53M), add n-BuLi (2.05eq) at -25℃, and stir at room temperature for 5 hours did For the resulting reactant, a slurry prepared by mixing ZrCl ₄ (1 eq) in toluene (0.17 M) was added to a separate flask at -25 °C and stirred overnight at room temperature.

After the reaction was completed, the solvent was vacuum-dried, dichloromethane (DCM) was reintroduced, LiCl was removed through a filter, and the filtrate was vacuum-dried and recrystallized at room temperature by adding DCM/hexane. Then, the resulting solid was filtered and vacuum dried to obtain the solid transition metal compound of the title.

Pseudo-rac: 7.72 (dd, 2H), 7.56 (d, 2H), 7.5–6.7 (m, 12H), 6.61 (s, 1H), 6.07 (s, 1H), 2.15 (s, 3H), 1.46 ( s, 3H), 1.3 (s, 9H), 1.07 (s, 3H) ppm

Synthesis Example 6

Dimethylsilanediyl (3-n-butyl-1H-inden-1-yl) (2- methyl -4-(4- tert - Butylphenyl )-1H- person den-1-yl) zirconium dichloride Manufacturing (precursor F)

(F)

(F)

Except for using 3-n-butyl-1H-indene instead of 3-phenyl-1H-indene in step 1 of Synthesis Example 5, the transfer of the title was carried out in the same manner as in Synthesis Example 5. A metal compound was prepared.

Pseudo-rac: 7.57 (d, 1H), 7.4–6.8 (m, 10H), 6.61 (s, 1H), 5.67 (s, 1H), 2.86 (t, 2H), 2.16 (s, 3H), 1.58 ( m, 2H), 1.42 (s, 3H), 1.33 (s, 9H), 1.4-1.2 (m, 2H), 1.03 (s, 3H), 0.92 (t, 3H) ppm

Synthesis Example 7

dimethylsilanediyl (3-isopropyl-1H- inden -1-day)(2- methyl -4-(4- tert - Butylphenyl )-1H-inden-1-yl)zirconium dichloride Manufacturing (precursor G)

(G)

(G)

The title transition metal compound was carried out in the same manner as in Steps 1 and 2, except that 3-isopropyl-1H-indene was used instead of 3-phenyl-1H-indene in Step 1 of Synthesis Example 5. was manufactured.

Pseudo-rac: 8.29 (d, 1H), 7.49-7.30 (m, 9H), 7.16 (d, 1H), 6.36 (s, 1H),6.17 (s, 1H), 2.38 (q, 2H), 2.08 ( s, 3H), 1.33 (s, 9H), 0.86 (d, 6H), 0.72 (s, 6H) ppm

<Production Example of Supported Catalyst>

Preparation Example 1

Silica gel (10 g, Sylopol2410) was placed in a 500 mL high-pressure glass reactor under Ar, and 10 wt% MAO toluene solution (90 mmol) was slowly injected at room temperature, followed by stirring at 95° C. for 15 hours. After completion of the reaction, the mixture was cooled to room temperature, left for 15 minutes, and the solvent was decanted using a cannula. 80 mL of toluene was added and stirred for 1 minute.

In a 50ml vial, the precursor A (1.2mmol) prepared in Synthesis Example 1 and the precursor E (0.8mmol) prepared in Synthesis Example 5 were dissolved in 30ml toluene, respectively, and then transferred to the reactor using a cannula and washed with 20ml toluene. did After stirring at 60° C. for 5 hours, the mixture was cooled to room temperature, allowed to stand for 15 minutes, and the solvent was decanted using a cannula. 80 ml of toluene was added, stirred for 10 minutes, allowed to stand for 10 minutes, and then decanted the solvent using a cannula twice. In the same way, 80 ml of hexane was added, stirred for 10 minutes, left for 20 minutes, and then the solvent was decanted using a cannula. After drying under vacuum at room temperature for 4 hours, and further drying under vacuum at 45° C. for 2 hours, a hybrid supported catalyst containing precursors A and E was prepared.

Preparation Example 2

Carried out in the same manner as in Preparation Example 1, except that precursor B (1.2 mmol) prepared in Synthesis Example 2 was used instead of precursor A in Preparation Example 1, and precursor E was used in an amount of 0.6 mmol. Thus, a hybrid supported catalyst including precursors B and E was prepared.

Preparation Example 3

Except for using precursor C (1.2 mmol) prepared in Synthesis Example 3 instead of precursor A in Preparation Example 1 and using precursor F (0.4 mmol) prepared in Synthesis Example 6 instead of precursor E, the above A hybrid supported catalyst including precursors C and F was prepared in the same manner as in Preparation Example 1.

Production Example 4

Except for using precursor D (0.8 mmol) prepared in Synthesis Example 4 instead of precursor A in Preparation Example 1 and using precursor G (0.8 mmol) prepared in Synthesis Example 7 instead of precursor E, A hybrid supported catalyst including precursors D and G was prepared in the same manner as in Preparation Example 1.

Comparative Preparation Example 1

Silica gel (10 g, Sylopol2410) was placed in a 500 mL high-pressure glass reactor under Ar, and 10 wt% MAO toluene solution (90 mmol) was slowly injected at room temperature, followed by stirring at 95° C. for 15 hours. After completion of the reaction, the mixture was cooled to room temperature, left for 15 minutes, and the solvent was decanted using a cannula. 80 mL of toluene was added and stirred for 1 minute.

The precursor A (1.0 mmol) prepared in Synthesis Example 1 was dissolved in 30 ml of toluene in a 50 ml vial, transferred to the reactor using a cannula, and washed with 20 ml of toluene. After stirring at 60° C. for 5 hours, the mixture was cooled to room temperature, allowed to stand for 15 minutes, and the solvent was decanted using a cannula. 80 ml of toluene was added, stirred for 10 minutes, allowed to stand for 10 minutes, and then decanted the solvent using a cannula twice. In the same way, 80 ml of hexane was added, stirred for 10 minutes, left for 20 minutes, and then the solvent was decanted using a cannula. After drying under vacuum at room temperature for 4 hours, and further drying under vacuum at 45° C. for 2 hours, a supported catalyst containing precursor A was prepared.

Comparative Preparation Example 2

Except for using the precursor E (1.6 mmol) prepared in Synthesis Example 5 instead of the precursor A in Comparative Preparation Example 1, carried out in the same manner as in Comparative Preparation Example 1, the support containing precursor E A catalyst was prepared.

Comparative Preparation Example 3

Precursor A was carried out in the same manner as in Preparation Example 1, except that in Preparation Example 1, precursor A was used in an amount of 0.8 mmol, and precursor H (0.4 mmol) having the following structure was used instead of precursor E, A supported hybrid catalyst containing H and H was prepared.

(H)

(H)

Comparative Preparation Example 4

In the same manner as in Preparation Example 1, except that precursor H (0.9 mmol) was used instead of precursor A in Preparation Example 1, and precursor E prepared in Synthesis Example 5 was used in an amount of 0.3 mmol. This was carried out to prepare a hybrid supported catalyst comprising precursors H and E.

<Olefin Polymerization Example>

Example 1: Homo polymerization

A 2L high-pressure autoclave reactor was vacuum-dried at about 70° C., then cooled to 30° C., and 1.0 mmol of triisobutylaluminum (TIBAL), 300 ppm of hydrogen, and 770 g of propylene were sequentially added thereto. After stirring at 500 rpm for about 10 minutes, 50 mg of the hybrid supported catalyst prepared in Preparation Example 1 was diluted in 20 ml of normal hexane and introduced into the reactor under nitrogen pressure. Thereafter, the temperature of the reactor was raised to 63° C. within 5 minutes, followed by polymerization for 60 minutes. After completion of the reaction, unreacted propylene was vented and dried to obtain homopolypropylene.

Examples 2 to 4: Homo polymerization

In Example 1, it was carried out in the same manner as in Example 1, except that the supported hybrid catalysts prepared in Preparation Examples 2 to 4 were used instead of the supported hybrid catalysts prepared in Preparation Example 1, respectively. Propylene was prepared.

Example 5: Ethylene Random Polymerization

A 2L high-pressure autoclave reactor was vacuum-dried at about 70° C., then cooled to 30° C., and 1.0 mmol of triisobutylaluminum (TIBAL), 100 ppm of hydrogen, and 770 g of propylene were sequentially added thereto. Then, while stirring at 500 rpm for about 10 minutes, the temperature of the reactor was raised to 63°C. 50 mg of the supported hybrid catalyst prepared in Preparation Example 2 was diluted in 20 ml of normal hexane and introduced into the reactor under nitrogen pressure, and then ethylene gas was introduced into the reactor through the MFC at a rate of 30 cc/min to polymerize for 60 minutes. After completion of the reaction, unreacted propylene was vented and dried to obtain a propylene-ethylene random copolymer (C2-random).

Example 6: Ethylene Random Polymerization

In Example 5, except for using the hybrid supported catalyst prepared in Preparation Example 4 instead of the supported hybrid catalyst prepared in Preparation Example 2, propylene-ethylene random air A composite (C2-random) was prepared.

Comparative Examples 1 to 4: Homo polymerization

In Example 1, it was carried out in the same manner as in Example 1 except for using the catalysts prepared in Comparative Preparation Examples 1 to 4 instead of the hybrid supported catalyst prepared in Preparation Example 1, respectively, homo polypropylene was manufactured.

Comparative Examples 5 to 7: Ethylene Random Polymerization

In Example 5, propylene- An ethylene random copolymer was prepared.

<Experimental example>

Evaluation of polyolefin properties

The activity of the catalyst used in Examples and Comparative Examples and the physical properties of the obtained polymer were evaluated in the following manner, and the results are shown in Table 1.

(1) Catalytic activity

It was calculated as the ratio of the weight of the produced polymer (kg PP) per the supported catalyst mass (g) used per unit time (h).

(2) Melt Index (MI, 2.16kg)

It was measured under a load of 2.16 kg at 230 ° C according to ASTM D1238 and expressed as the weight (g) of the polymer melted for 10 minutes.

(3) weight average molecular weight (Mw), number average molecular weight (Mn) and molecular weight distribution (MWD):

The weight average molecular weight (Mw) and number average molecular weight (Mn) of the polymer were measured using gel permeation chromatography (GPC: gel permeation chromatography, manufactured by Waters), and the molecular weight distribution (MWD) was divided by the weight average molecular weight by the number average molecular weight. =Mw/Mn) was calculated.

Specifically, polypropylene samples were evaluated using a Waters PL-GPC220 instrument using a Polymer Laboratories PLgel MIX-B 300 mm long column. The evaluation temperature was 160°C, 1,2,4-trichlorobenzene was used as a solvent, and the flow rate was measured at a rate of 1 mL/min. The sample was prepared at a concentration of 10mg/10mL and then supplied in an amount of 200 μL. The values of Mw and Mn were determined using a calibration curve formed using polystyrene standards. The molecular weight (g/mol) of polystyrene standard was 2,000 / 10,000 / 30,000 / 70,000 / 200,000 / 700,000 / 2,000,000 / 4,000,000 / 10,000,000.

(4) melting point (Tm1, Tm2) and melting point difference (ΔTm)

The melting point of polypropylene was measured using a differential scanning calorimeter (DSC, device name: DSC 2920, manufacturer: TA instrument) according to ASTM D3418. Specifically, after increasing the temperature of the polypropylene to be measured to 200 ° C, maintaining it at that temperature for 5 minutes, then lowering it to 30 ° C, and increasing the temperature again to obtain a DSC (Differential Scanning Calorimeter, manufactured by TA) curve The top was taken as the melting point. At this time, the rate of temperature rise and fall was 10 °C/min, and the result measured in the second temperature rising section was used for the melting point.

(5) Xylene soluble content (XS)

Xylene was added to polypropylene, heated at 135° C. for 1 hour, and pretreated by cooling for 30 minutes. In OminiSec (Viscotek's FIPA) equipment, xylene was flowed for 4 hours at a flow rate of 1 mL/min, and RI (Refractive Index), DP (Pressure across middle of bridge), IP (Inlet pressure through bridge top) When the base line of the bottom was stabilized, the concentration of the pretreated sample and the amount of injection were measured, and then the peak area was calculated.

(6) Bulk density (g/cm ³ )

It was obtained by measuring the weight (g) of polypropylene entering a 100 mL container using IPT model 1132.

(7) Shrinkage rate

According to ASTM D955, the shrinkage length (mm) of a specimen having a thickness of 3 mm and a length of 1000 mm was measured, and the shrinkage rate was obtained according to the following equation.

[Equation 1]

Shrinkage rate (%) = [length of specimen to shrink (mm) / length of specimen before shrinkage (1000mm)] ⅹ 100

Example One 2 3 4 5 6 hydrogen input
(ppm) 300 300 300 300 100 100 polymer type Homo Homo Homo Homo C2-random C2-random Catalytic activity (kg/g Cat hr) 5.1 3.9 5.5 4.9 4.4 5.2 MI (g/10min) 19 25 22 27 11 13 MWD 3.7 3.9 3.1 3.3 3.7 3.5 Tm1/Tm2 (℃) 155/146 157/146 153/145 156/144 132/123 133/124 △Tm (℃) 9 11 8 12 9 9 X.S (wt%) 0.7 0.5 0.6 0.8 0.8 0.8 BD (g/cm ³ ) 0.41 0.41 0.42 0.43 0.37 0.39 Shrinkage (%) 2.4 2.6 2.0 2.2 - -

comparative example One 2 3 4 5 6 7 hydrogen input
(ppm) 300 300 300 300 100 100 100 polymer type Homo Homo Homo Homo C2-random C2-random C2-random Catalytic activity (kg/g Cat hr) 6.1 4.5 4.0 4.2 6.6 - 4.3 MI
(g/10min) 25 8 13 6 15 - 21 MWD 3.3 2.7 3.6 2.9 3.5 - 3.5 Tm or Tm1/Tm2 (℃) 156 144 153 151/146 131 - 135 △Tm (℃) - - - 5 - - - X.S (wt%) 0.7 0.7 0.9 0.6 0.8 - 0.9 BD (g/cm ³ ) 0.40 0.40 0.40 0.40 0.38 - 0.38 Shrinkage (%) 1.3 1.6 1.5 1.7 - - -

In Tables 1 and 2, "-" means not measured.

As a result of the experiment, the polypropylenes of Examples 1 to 6 prepared using the supported hybrid catalyst according to the present invention had almost similar levels of MI, MWD, XS, and BD compared to the polypropylene prepared using the conventional supported catalyst. However, it specifically showed two melting points, and the temperature difference between the two melting points exceeded 5 ° C, specifically more than 8 ° C. As such, by having a melting point having a temperature difference of a certain level or more, it is possible to exhibit excellent sinterability between beads during bead form molding, and it can be seen that it is more useful in manufacturing a highly flexible nonwoven fabric due to improved shrinkage due to the difference in melting point.

Claims (15)

A first transition metal compound represented by Formula 1 below;
A second transition metal compound represented by Formula 2 below; and
Hybrid Supported Catalyst, Comprising a Carrier:
[Formula 1]

[Formula 2]

In Formulas 1 and 2,
A ₁ and A ₂ are each independently carbon, silicon or germanium;
M ₁ and M ₂ are each independently a group 14 element;
R ₁₁ to R ₁₄ are each independently C _1-20 alkyl;
R ₁₅ and R ₁₆ are each independently C _1-20 alkyl, C _1-20 alkoxy, or C _2-20 alkoxyalkyl;
R ₂₁ is C _1-20 alkyl; or C _6-20 aryl unsubstituted or substituted with C _1-20 alkyl;
R ₂₂ is C _6-20 aryl substituted with C _1-20 alkyl;
R ₂₃ and R ₂₄ are each independently C _1-20 alkyl;
X ₁₁ , X ₁₂ , X ₂₁ and X ₂₂ are each independently halogen.
According to claim 1,
In Formula 1, A ₁ is silicon, M ₁ is zirconium or hafnium, R ₁₁ to R ₁₄ are each independently C _3-6 branched chain alkyl, and R ₁₅ and R ₁₆ are each independently C _1-4 straight chain. A hybrid supported catalyst, which is a C _3-10 alkyl group substituted with an alkyl group or a C _3-6 branched-chain alkoxy group.
According to claim 1,
The first transition metal compound is any one of the compounds represented by the following structural formula, the hybrid supported catalyst.

According to claim 1,
In Formula 2, A ₂ is silicon, M ₂ is zirconium, R ₂₁ is C _3-10 straight-chain alkyl; C _3-10 branched chain alkyl; phenyl; or phenyl substituted with C _3-10 branched-chain alkyl, R ₂₂ is phenyl substituted with C _3-6 branched-chain alkyl, and R ₂₃ and R ₂₄ are each C _1-4 straight-chain alkyl.
According to claim 1,
The second transition metal compound is any one of the compounds represented by the following structural formula, the hybrid supported catalyst.

According to claim 1,
The first transition metal compound and the second transition metal compound are included in a molar ratio of 6: 1 to 1: 6, the hybrid supported catalyst.
According to claim 1,
Wherein the carrier is silica, the hybrid supported catalyst.
According to claim 1,
The hybrid supported catalyst further comprises an alkylaluminoxane-based cocatalyst.
A method for producing polypropylene comprising the step of polymerizing propylene monomers by introducing hydrogen in the presence of the supported hybrid catalyst according to any one of claims 1 to 8.
According to claim 9,
A method for producing polypropylene in which ethylene monomer is further added during polymerization of the propylene monomer.
According to claim 9,
The hydrogen is added in an amount of 30 to 800ppm based on the total weight of the monomers, a method for producing polypropylene.
According to claim 9,
The polypropylene has two melting points (Tm1 and Tm2), and the temperature difference (ΔTm) between the two melting points is greater than 5 ° C.
A homopolypropylene having two melting points (Tm1 and Tm2), a temperature difference (ΔTm) between the two melting points being greater than 5°C and less than or equal to 20°C, and further satisfying the following conditions:
First melting point (Tm1): 130 to 160 ℃, second melting point (Tm2): 120 to 150 ℃
Melt index (measured at 230 ° C under a load of 2.16 kg according to ASTM D1238): 5 to 40 g / 10 min
Molecular weight distribution: 3 to 5
Xylene soluble content: 1.0% by weight or less.
According to claim 13,
Homo polypropylene, wherein the temperature difference (ΔTm) between the two melting points is greater than 7° C. and less than or equal to 20° C.
According to claim 13,
Homo polypropylene, further meeting the following conditions:
First melting point (Tm1): 152 to 158 ℃, second melting point (Tm2): 143 to 147 ℃
Melt index (measured under the condition of 2.16 kg load at 230 ° C according to ASTM D1238): 10 g / 10 min or more and 30 g / 10 min or less
Molecular weight distribution: 3 or more and 4 or less
Xylene soluble content: 0.7% by weight or less.