KR102396402B1 - Homo polypropylene and method for preparing the same - Google Patents

Abstract

The present invention provides a homo polypropylene having excellent processability and mechanical properties such as high strength and a manufacturing method thereof. The homo polypropylene satisfies i) a molecular weight distribution of 2.4 or less, ii) a residual stress ratio of 0.2% to 0.5%, and iii) a complex viscosity of 450 to 600 Pa·s at 1 rad/s.

Description

Homo polypropylene and its manufacturing method

The present invention relates to a homo polypropylene having excellent processability and mechanical properties such as high strength, and a method for manufacturing the same.

Olefin polymerization catalyst systems can be classified into Ziegler-Natta and metallocene catalyst systems, and these two highly active catalyst systems have been developed according to their respective characteristics. Ziegler-Natta catalyst has been widely applied to existing commercial processes since its invention in the 1950s. There is a problem in that there is a limit to securing the desired physical properties because the composition distribution is not uniform.

On the other hand, the metallocene catalyst is composed of a combination of a main catalyst containing a transition metal compound as a main component and a cocatalyst containing an organometallic compound containing aluminum as a main component. Such a catalyst is a homogeneous complex catalyst and is a single site catalyst. The molecular weight distribution is narrow according to the single active point characteristic, and a polymer with a uniform composition distribution of the comonomer is obtained. It has properties that can change crystallinity, etc.

Homo polypropylene, which is usually prepared with a Ziegler-Natta catalyst, has problems in that when the strength is increased or the basis weight is lowered, physical properties are lowered as well as workability is lowered.

In order to compensate for these shortcomings, attempts have been made to improve the processability and mechanical properties of homopolypropylene by using a metallocene catalyst. However, even in the case of producing homopolypropylene using the previously developed metallocene catalyst, the viscosity in the processing region is too high, so that the processability is not sufficient, or, conversely, the viscosity in the processing region is to the extent that it is possible to secure the processability, There were disadvantages such as a decrease in strength.

Accordingly, until now, homo polypropylene with improved mechanical properties such as processability and strength has not been properly developed.

Accordingly, the present invention provides a homopolypropylene having excellent processability and mechanical properties such as high strength, and a method for manufacturing the same.

The present invention provides a homo polypropylene satisfying the following conditions:

i) molecular weight distribution 2.4 or less

ii) Residual stress ratio 0.2% to 0.5%

iii) a complex viscosity of 450 to 600 Pa·s at an angular rate of 1 rad/s, and a complex viscosity of 200 to 300 Pa·s at an angular rate of 100 rad/s.

The present invention also provides a silica carrier; and polymerizing a propylene monomer in the presence of a supported catalyst including a supported catalyst including the compound of Formula 1 supported on a silica carrier and a cocatalyst, it provides a method for producing the homopolypropylene of the present invention:

[Formula 1]

In Formula 1,

X ₁ and X ₂ are each independently halogen,

R ₁ and R ₅ are each independently C _6-20 aryl substituted with C _1-20 alkyl;

R ₂ to R ₄ and R ₆ to R ₈ are each independently hydrogen, halogen, C _1-20 alkyl, C _2-20 alkenyl, C _1-20 alkylsilyl, C _1-20 silylalkyl, C _1-20 alkoxysilyl, C _1-20 ether, C _1-20 silylether, C _1-20 alkoxy, C _6-20 aryl, C _7-20 alkylaryl, or C _7-20 arylalkyl;

A is carbon, silicon or germanium.

In addition, the present invention provides a molded article comprising the homo polypropylene of the present invention.

The homo polypropylene according to the present invention may exhibit a higher LCB (Long Chain Branch) content and an appropriate distribution thereof, as it is prepared with a specific catalyst or the like. As a result, improved mechanical properties such as high strength can be exhibited along with excellent processability.

The homo polypropylene of the present invention can be very preferably used for various molded articles and the like.

1 is a 13C NMR analysis result of the homo polypropylene of Example 1 and Comparative Example 2, and is an analysis result confirming that LCB is generated in Example 1, unlike Comparative Example 2.
2 is a graph showing the results of measuring the molecular weight distribution of the homo polypropylene of Example 1 and Comparative Examples 1 to 3 as GPC.
3 is a graph showing the results of measuring the composite viscosity for each rate for the homo polypropylene of Example 1 and Comparative Examples 1 to 3;
4 is a graph showing the results of measuring the residual stress and residual stress ratio for the homo polypropylene of Example 1 and Comparative Examples 1 to 3;

The terminology used herein is used to describe exemplary embodiments only, and is not intended to limit the invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In this specification, terms such as "comprises", "comprising" or "have" are intended to designate the presence of an embodied feature, step, element, or a combination thereof, but one or more other features or steps; It should be understood that the possibility of the presence or addition of components, or combinations thereof, is not precluded in advance.

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

According to one embodiment of the invention, there is provided a homo polypropylene satisfying the following conditions:

i) molecular weight distribution 2.4 or less

ii) Residual stress ratio 0.2% to 0.5%

iii) a complex viscosity of 450 to 600 Pa·s at an angular rate of 1 rad/s, and a complex viscosity of 200 to 300 Pa·s at an angular rate of 100 rad/s.

As a result of continuous experiments by the present inventors, it was confirmed that as propylene is polymerized under a specific supported catalyst described below, the generation of LCB (Long Chain Branch) is accompanied at a certain level or more, thereby forming an appropriately distributed homo polypropylene. .

It was confirmed that the homo polypropylene exhibits a relatively narrow molecular weight distribution according to the proper production and distribution of the LCB, and exhibits a high complex viscosity at a low angular velocity, thereby exhibiting improved mechanical properties.

In addition, it was confirmed that, under a high angular speed corresponding to the processing area, a low complex viscosity was exhibited, and an appropriate residual stress ratio was exhibited to indicate excellent processability.

As a result, the homo polypropylene of one embodiment can be very preferably used for various molded articles and the like due to excellent processability and improved mechanical properties.

Hereinafter, the physical properties and manufacturing method of the homo polypropylene of one embodiment will be described in more detail.

The homo polypropylene according to an embodiment of the present invention may exhibit a narrow molecular weight distribution (MWD=Mw/Mn) of 2.4 or less. By having such a narrow molecular weight distribution, mechanical properties such as excellent strength can be exhibited when manufacturing various molded articles. More specifically, the homo polypropylene may have an MWD of 1.5 to 2.4, and more specifically, 2.0 to 2.35. The molecular weight distribution of the homo polypropylene can be calculated by measuring the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the polymer using gel permeation chromatography (GPC), respectively, and converting from them. . When measuring the GPC, polystyrene or the like may be used as a standard material.

In addition, the homo polypropylene according to an embodiment of the present invention may have a relatively high residual stress ratio of 0.2% to 0.5%, or 0.25% to 0.45%, or 0.3% to 0.4%.

The residual stress ratio can be measured/confirmed through a rheological property test, and a stress relaxation test is performed by applying a large strain to the homo polypropylene, and it is a value measured according to the following formula 1 .

[Formula 1]

Residual stress ratio = (RS ₁ /RS ₀ )*100

In Equation 1, RS ₀ is the residual stress at any one time point (t ₀ ) less than 0.05 seconds after applying 200% strain to the homo polypropylene under 235 ° C., and RS ₁ is the homo polypropylene under 235 ° C. It is the residual stress at any one time point (t ₁ ) between 0.05 sec and 1.50 sec after applying a strain of 200%.

If the ratio of residual stress according to Equation 1 exceeds 0.5%, dimensional stability may decrease, resulting in defects and deformation of the product surface. If it is less than 0.2%, injection requiring high flowability During molding, a problem of deterioration of workability may occur.

In addition, in Equation 1, RS ₀ represents the residual stress immediately after applying a strain of 200% to the homopolypropylene at 235° C. (eg, at any one time point (t ₀ ) less than 0.05 seconds). And, in Equation 1, RS ₁ represents a residual stress within about 1.5 seconds after t ₀ under the same conditions as RS ₀ [for example, any one time point (t ₁ ) between 0.05 seconds and 2.00 seconds].

Specifically, in Equation 1, t ₀ may be selected from 0.01 second, or 0.015 second, or 0.02 second, or 0.025 second, or 0.03 second, or 0.035 second, or 0.04 second, or 0.045 second. And, in Equation 1, t ₁ is 0.05 second, or 0.10 second, or 0.20 second, or 0.30 second, or 0.40 second, or 0.50 second, or 0.60 second, or 0.70 second, or 0.80 second, or 0.90 second, or 1.00 seconds, or 1.10 seconds, or 1.20 seconds, or 1.30 seconds, or 1.40 seconds, or 1.50 seconds, or 1.60 seconds, or 1.70 seconds, or 1.80 seconds, or 1.90 seconds, or 2.00 seconds. Preferably, in order to easily secure valid data when measuring the residual stress, it may be advantageous for t ₀ to be 0.02 seconds and t ₁ to be 1.00 seconds in Equation 2 above.

In addition, the residual stress ratio of the homo polypropylene is measured under an environment (eg, 235° C.) similar to the process conditions during melt processing thereof. The temperature of 235 ° C. corresponds to a temperature suitable for completely dissolving the homo polypropylene composition to perform melt processing.

On the other hand, the homo polypropylene of the embodiment has a complex viscosity of 450 to 600 Pa·s, or 460 to 550 Pa·s, or 470 to 520 Pa·s at an angular rate of 1 rad/s, and an angular rate of 100 rad/s The complex viscosity at s may be 200 to 300 Pa·s, or 210 to 250 Pa·s.

The complex viscosity according to each speed can be obtained by dynamic frequency sweep at 190°C using an advanced rheometric expansion system (ARES). The dynamic frequency sweep can be measured using a disk-shaped 25 mm parallel plate.

The complex viscosity according to each speed is related to fluidity and/or processability, and the homopolypropylene of one embodiment has a high complex viscosity at a low angular speed, so it can exhibit excellent mechanical properties such as strength, and a high corresponding to the processing area. At each speed, a low complex viscosity can be exhibited, resulting in excellent fluidity and improved processability.

That is, the homo polypropylene of one embodiment shows a large degree of change in the complex viscosity according to each rate compared to the conventional homo polypropylene having a similar density and weight average molecular weight in the complex viscosity graph according to each rate, and accordingly, the shear Excellent thinning effect and excellent mechanical properties and processability can be exhibited together.

In addition, the homo polypropylene may exhibit a high tacticity of xylene solubles (Xs) of 1.0 wt% or less.

The xylene soluble content is the content (wt%) of a polymer soluble in cooled xylene determined by dissolving homopolypropylene in xylene and crystallizing an insoluble portion from the cooling solution, and the xylene soluble content is a polymer chain with low stereoregularity. contains Accordingly, the lower the content of the xylene-soluble component, the higher the stereoregularity. Homo polypropylene according to an exemplary embodiment may exhibit excellent rigidity in manufacturing various products as it has such a high stereoregularity. Considering the superiority of the improvement effect according to the control of the xylene-soluble content, the xylene-soluble content of the homo polypropylene may be more specifically 0.5 to 1.0 wt%, and even more specifically 0.6 to 0.7 wt%.

In addition, the homo polypropylene of the embodiment has a melt index (MI) measured under a load of 2.16 kg at 230°C according to ASTM D 1238 of 5 to 3000 g/min, or 7 to 2500 g/min, or 9 to 2000 g/min.

The homopolypropylene may exhibit various melt indexes depending on the type of product to be manufactured using the same and physical properties to be achieved, and such melt index may be adjusted according to the amount of hydrogen input during the polymerization process.

In addition, the homo polypropylene according to an embodiment of the present invention may have a weight average molecular weight (Mw) of 30000 to 300000, or 50000 to 250000. By having such a molecular weight, mechanical properties such as excellent strength and other appropriate physical properties can be exhibited in the manufacture of various molded articles.

The weight average molecular weight of the homo polypropylene may be measured using gel permeation chromatography (GPC), and polystyrene or the like may be used as a standard material in the measurement of GPC.

Homo polypropylene according to an embodiment of the present invention having the above physical properties is a silica carrier; And in the presence of a supported catalyst including a cocatalyst and the compound of Formula 1 supported on a silica carrier, it may be prepared by a manufacturing method comprising the step of polymerizing a propylene monomer:

[Formula 1]

In Formula 1,

X ₁ and X ₂ are each independently halogen,

R ₁ and R ₅ are each independently C _6-20 aryl substituted with C _1-20 alkyl;

R ₂ to R ₄ and R ₆ to R ₈ are each independently hydrogen, halogen, C _1-20 alkyl, C _2-20 alkenyl, C _1-20 alkylsilyl, C _1-20 silylalkyl, C _1-20 alkoxysilyl, C _1-20 ether, C _1-20 silylether, C _1-20 alkoxy, C _6-20 aryl, C _7-20 alkylaryl, or C _7-20 arylalkyl;

A is carbon, silicon or germanium.

As a result of continuous experiments by the present inventors, it was confirmed that by using the supported catalyst including Chemical Formula 1 and the cocatalyst, the homo polypropylene of one embodiment can be prepared by the following technical principles.

First, as the compound of Formula 1 is used as a single catalytically active species, the molecular weight distribution may be narrowed compared to the prepared homo polypropylene compared to the case where two or more catalysts are mixed and used.

Moreover, the compound of Formula 1, as a bridge group connecting two ligands including an indenyl group, includes the same alkyl group having 2 or more carbon atoms, that is, a divalent functional group A bisubstituted with an ethyl group, thereby increasing the atomic size compared to the existing carbon bridge As a result, as the solubility angle increases, the monomer can be easily accessed, thereby exhibiting superior catalytic activity.

In addition, the 2-position of the two indenyl groups that are ligands is substituted with a methyl group/isopropyl group, respectively, and the 4-position (R ₁ and R ₅ ) contains an alkyl-substituted phenyl group, respectively, so that sufficient electrons can be supplied to the inductive effect. can exhibit better catalytic activity and, by forming the LCB in an appropriate ratio/distribution in the structure of the homo polypropylene, homo polypropylene satisfying all physical properties of one embodiment can be prepared.

In addition, since the compound of Formula 1 contains zirconium (Zr) as a central metal, it has more orbitals capable of accepting electrons compared to when it contains other Group 14 elements such as Hf, so that it is a monomer with higher affinity. and can be easily combined, and as a result, it is possible to exhibit a more excellent catalytic activity improvement effect.

Unless otherwise limited herein, the following terms may be defined as follows.

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

The C _1-20 alkyl group may be a straight chain, branched chain or cyclic alkyl group. Specifically, the C _1-20 alkyl group is a C _1-15 straight-chain alkyl group; C _1-10 straight chain alkyl group; C _1-5 straight chain alkyl group; C _3-20 branched or cyclic alkyl group; C _3-15 branched or cyclic alkyl group; Or it may be a C _3-10 branched or cyclic alkyl group. More specifically, the C _1-20 alkyl group is a methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, tert-butyl group, n-pentyl group, iso-pentyl group, It may be a neo-pentyl group or a cyclohexyl group.

The C _2-20 alkenyl group may be a straight chain, branched chain or cyclic alkenyl group. Specifically, C _2-20 alkenyl group is C _2-20 straight chain alkenyl group, C _2-10 straight chain alkenyl group, C _2-5 straight chain alkenyl group, C _3-20 branched chain alkenyl group, C _3-15 branched chain alkenyl group It may be a nyl group, a C _3-10 branched chain alkenyl group, a C _5-20 cyclic alkenyl group, or a C _5-10 cyclic alkenyl group. More specifically, the C _2-20 alkenyl group may be an _ethenyl group, a propenyl group, a butenyl group, a pentenyl group, or a cyclohexenyl group.

C _6-20 aryl may 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 _7-30 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 the alkyl are substituted by aryl. Specifically, C _7-30 arylalkyl may be a benzyl group, phenylpropyl, or phenylhexyl.

More specifically, in Formula 1, R ₁ and R ₅ may each independently be a C _6-12 aryl group substituted with C _1-10 alkyl, and more specifically, a C _3-6 branched chain such as tert-butyl phenyl. It may be a phenyl group substituted with an alkyl group. Also, the substitution position of the alkyl group with respect to the phenyl group may be the 4th position corresponding to the R ₁ or R ₅ position and the para position bonded to the indenyl group.

In addition, in Formula 1, R ₂ to R ₄ and R ₆ to R ₈ may each independently be hydrogen, and X ₁ and X ₂ may each independently be chloro.

In addition, in Formula 1, A may be silicon. In addition, R ₉ and R ₁₀ , which are the substituents of A, are the same as each other in terms of improving the loading efficiency by increasing solubility, and may each be ethyl. In the case of using a previously known methyl group as a substituent of such a bridge, solubility may be poor when preparing a supported catalyst, and thus a problem of poor supported reactivity may appear.

Representative examples of the compound represented by Formula 1 are as follows:

[Formula 1a]

The compound of Formula 1 may be synthesized by applying known reactions, and more detailed synthesis methods may refer to Preparation Examples to be described later.

Meanwhile, the compound of Formula 1 may be typically used in the state of a supported catalyst supported on a silica carrier.

As the silica carrier, a carrier containing a hydroxyl group on the surface may be used, and preferably, one having a highly reactive hydroxyl group and a siloxane group, which is dried to remove moisture from the surface, may be used. For example, silica dried at high temperature, silica-alumina, and silica-magnesia may be used, and these are typically oxides, carbonates, such as Na ₂ O, K ₂ CO ₃ , BaSO ₄ , and Mg(NO ₃ ) ₂ ; It may contain sulfate, and nitrate components.

The drying temperature of the carrier is preferably 200 to 800°C, more preferably 300 to 600°C, and most preferably 300 to 400°C. When the drying temperature of the carrier is less than 200 ℃, there is too much moisture and the surface moisture and the cocatalyst react. It disappears and only the siloxane remains, which is not preferable because the reaction site with the promoter decreases.

The amount of hydroxyl groups on the surface of the carrier is preferably 0.1 to 10 mmol/g, more preferably 0.5 to 5 mmol/g. The amount of hydroxyl groups on the surface of the carrier can be controlled by the method and conditions or drying conditions of the carrier, such as temperature, time, vacuum or spray drying, and the like.

If the amount of the hydroxyl group is less than 0.1 mmol/g, there are few reaction sites with the co-catalyst, and if it exceeds 10 mmol/g, it is not preferable because it may be caused by moisture other than the hydroxyl group present on the surface of the carrier particle. not.

In addition, when supported on a carrier, the mass ratio of the compound of Formula 1 to the carrier is preferably 1:1 to 1:1000. When the carrier and the compound of Formula 1 are included in the above mass ratio, an appropriate supported catalyst activity may be exhibited, which may be advantageous in terms of maintaining the activity of the catalyst and economic feasibility.

In addition, the catalyst composition may further include a co-catalyst in addition to the compound represented by Formula 1 and the carrier, in terms of improving high activity and process stability. The cocatalyst may include at least one of aluminoxane-based compounds represented by the following Chemical Formula 2:

[Formula 2]

-[Al(R ₁₁ )-O] _m -

In Formula 2,

R ₁₁ may be the same as or different from each other, and each independently halogen; C _1-20 hydrocarbons; or a C _1-20 hydrocarbon substituted with halogen;

m is an integer greater than or equal to 2;

Examples of the compound represented by Formula 2 include methylaluminoxane, ethylaluminoxane, isobutylaluminoxane, butylaluminoxane, and the like, and a more preferable compound is methylaluminoxane.

When the catalyst composition includes both a carrier and a cocatalyst, it may be prepared by a manufacturing method comprising the steps of supporting the cocatalyst compound on a carrier, and supporting the compound represented by Formula 1 on the carrier. , In this case, the loading order of the cocatalyst and the compound of Formula 1 may be changed as needed.

In addition, the catalyst composition in the form of the supported catalyst may further include an antistatic agent. As such an antistatic agent, for example, an amine alcohol-based compound such as the following Chemical Formula A (product name: Atmer 163) may be used, and in addition to the antistatic agent, any component clearly known as an antistatic agent may be used without limitation. By using such an antistatic agent, generation of static electricity during polymerization/manufacturing of homo polypropylene is suppressed, and homo polypropylene having superior physical properties including the above-described general properties can be prepared.

[Formula A]

A hydrocarbon solvent such as pentane, hexane, or heptane or an aromatic solvent such as benzene or toluene may be used as a reaction solvent in the preparation of the catalyst composition, that is, the supported catalyst.

The homopolypropylene may be prepared through a polymerization process in which a catalyst composition including the above-described supported catalyst and propylene are brought into contact with each other in the presence or absence of hydrogen gas.

At this time, the hydrogen gas may be added to be 50 to 2500 ppm based on the total weight of propylene. By controlling the amount of hydrogen gas used, the molecular weight distribution and fluidity of the homo polypropylene composition produced while exhibiting sufficient catalytic activity can be adjusted within a desired range, and thus a homo propylene polymer having appropriate physical properties can be prepared according to the use. there is. More specifically, it may be included in an amount of 50 ppm or more, or 70 ppm or more, and 2500 ppm or less, 2000 ppm or less, or 1000 ppm or less.

The homopolypropylene may be prepared by a continuous polymerization process, for example, various polymerization processes known as polymerization of olefin monomers, such as a continuous solution polymerization process, a bulk polymerization process, a suspension polymerization process, a slurry polymerization process, or an emulsion polymerization process. can be hired In particular, a continuous bulk-slurry polymerization process is preferable in terms of obtaining a uniform molecular weight distribution and commercial production of products.

Specifically, the polymerization reaction may be carried out at a temperature of about 40 to 110 °C or about 60 to 100 °C and a pressure of about 1 to 100 kgf/cm ² .

In addition, in the polymerization reaction, the catalyst may be used in a dissolved or diluted state in a solvent such as pentane, hexane, heptane, nonane, decane, toluene, benzene, dichloromethane, chlorobenzene, and the like. In this case, by treating the solvent with a small amount of alkylaluminum or the like, a small amount of water or air that may adversely affect the catalyst may be removed in advance.

Homo polypropylene according to an embodiment of the invention produced by the above-described manufacturing method has an appropriate residual stress ratio, a narrow molecular weight distribution, and a predetermined complex viscosity, so that it has excellent melt processability when molded into various products such as various molded articles and mechanical properties such as high strength.

Accordingly, according to another embodiment of the present invention, there is provided a molded article comprising the above-described homo polypropylene.

The product may be manufactured according to a conventional method except for using the homo polypropylene of the above-described embodiment.

Hereinafter, preferred embodiments are presented to help the understanding of the present invention. However, the following examples are only for illustrating the present invention, and the content of the present invention is not limited by the following examples.

comparison production example One:

The catalyst of the above formula was prepared by the following method.

After dissolving 2-methyl-4-tert-butylphenyl indene (20.0 g, 76 mmol) in toluene/THF=10/1 solution (230 mL), n-butyllithium solution (2.5 M, hexane solvent, 22 g) ) was slowly added dropwise at 0 °C, and then stirred at room temperature for one day. Thereafter, (6-t-butoxyhexyl)dichloromethylsilane (1.27 g) was slowly added dropwise to the mixed solution at -78°C, stirred for about 10 minutes, and then stirred at room temperature for one day. Then, water was added to separate the organic layer, and the solvent was distilled under reduced pressure to obtain (6-t-butoxyhexyl)(methyl)-bis(2-methyl-4-tert-butylphenylindenyl)silane.

After dissolving the previously prepared (6-t-butoxyhexyl)(methyl)-bis(2-methyl-4-phenyl)indenylsilane in toluene/THF = 5/1 solution (95 mL), n-butyllithium The solution (2.5 M hexane solvent, 22 g) was slowly added dropwise at -78°C, followed by stirring at room temperature for one day. Bis(N,N'-diphenyl-1,3-propanediamido)dichlorozirconium bis(tetrahydrofuran) [Zr(C ₅ H ₆ NCH ₂ CH ₂ CH ₂ NC ₅ H ₆ )Cl ₂ ( C ₄ H ₈ O) ₂ ] was dissolved in toluene (229 mL), added dropwise at -78°C, and stirred at room temperature for one day. After cooling the reaction solution to -78°C, HCl ether solution (1 M, 183 mL) was slowly added dropwise, followed by stirring at 0°C for 1 hour. After filtration and vacuum drying, hexane (350 mL) was added and stirred to precipitate crystals. The precipitated crystals were filtered and dried under reduced pressure to obtain [(6-t-butoxyhexylmethylsilane-diyl)-bis(2-methyl-4-tert-butylphenylindenyl)]zirconium dichloride.

comparison production example 2:

The catalyst of the above formula was prepared by the following method.

7-tert-butylphenyl-2-methylindene (34.4 mmol) was added to a 250 mL Schlenk flask and dried under reduced pressure. Anhydrous Toluene/THF (172/34 mL) was added and diluted under an argon atmosphere, and then n-BuLi 2.5 M in hexane (36.2 mmol, 14.5 mL) was slowly added at -25°C. After stirring at 25° C. for more than 4 hours, Et ₂ SiCl ₂ (17.2 mmol) was added to the reaction mixture, followed by stirring at 25° C. overnight. After extraction with MTBE and H ₂ O using a separatory funnel, MgSO ₄ was added to the organic layer to dry the remaining water. The solid was filtered through a reduced pressure filter, and the liquid was distilled under reduced pressure and concentrated.

(diethylsilane-diyl)-bis(2-methyl-4-tert-butyl-phenylindenyl)silane (10.7 mmol) was added to a 100 mL Schlenk flask and dried under reduced pressure. Anhydrous toluene (16.0 mL) and THF (1.60 mL) were added and diluted under an argon atmosphere, and then n-BuLi 2.5 M in hexane (22.5 mmol, 9.00 mL) was slowly added at -25°C. After stirring at 25°C for more than 2 hours, ZrCl ₄ ·2THF (10.7 mmol) in toluene slurry was slowly added at -25°C. After stirring at 25°C overnight, the mixture was dried under reduced pressure, diluted with anhydrous dichloromethane, LiCl and impurities were filtered using a G4 size glass filter, and the liquid was concentrated by distillation under reduced pressure. Rac. A product with a : Meso ratio of about 1.5 : 1 was obtained by using dichloromethane to obtain a racemic rich product.

comparison production example 3:

The catalyst of the above formula was prepared by the following method.

Add 7-tert-butylphenyl-2-isopropylindene (10.0 g, 34.4 mmol) to a 250 mL Schlenk flask and dry under reduced pressure. After dilution with anhydrous diethyl ether (172 mL) under an argon atmosphere, n-BuLi 2.5 M in hexane (36.2 mmol, 14.5 mL) is slowly added at -25°C. After stirring at 25°C for more than 4 hours, Me2SiCl2 (68.9 mmol, 8.30 mL) was added to the reaction mixture, followed by stirring at 25°C overnight. LiCl is filtered using a G4 size glass filter and the filtrate is dried under reduced pressure. In another 250 mL Schlenk flask, 7-tert-butylphenyl-2-methylindene (9.04 g, 34.4 mmol) and CuCN (1.72 mmol, 0.15 g) were added and dried under reduced pressure. After dilution with anhydrous toluene (208 mL) and THF (20.4 mL) under an argon atmosphere, n-BuLi 2.5 M in hexane (36.2 mmol, 14.5 mL) was slowly added at -25°C, followed by stirring at 25°C overnight. Pour the above mono-Si solution into this flask. After that, it is stirred at 25°C overnight, extracted with water, and dried. Put tert-butylamine (7.09 mmol, 0.74 mL) in a 100 mL Schlenk flask, and add Anhydrous toluene (7.88 mL) and THF (0.57 mL) under an argon atmosphere. After dilution, n-BuLi 2.5 M in hexane (7.44 mmol, 2.98 mL) is slowly added at -25°C. After stirring at 25°C for 2 hours or more, it was added to another schlenk flask containing ZrCl ₄ ·2THF (2.67 g, 7.09 mmol) and toluene (6.2 mL) at -25°C and stirred at 25°C for 2 hours or more. Add UT1 Ligand (4.32 g, 7.09 mmol) to another 100 mL Schlenk flask and dry under reduced pressure. After dilution with anhydrous toluene (11.8 mL) and THF (1.18 mL) under an argon atmosphere, n-BuLi 2.5 M in hexane (14.9 mmol, 5.96 mL) is slowly added at -25°C. After stirring at 25℃ for 2 hours or more, the Zr-tert-butylamide solution synthesized above is added at -25℃.

After overnight stirring at 25°C, HCl 1.0 M in diethyl ether (15.6 mmol, 15.6 mL) was added at -25°C and stirred for about 1 hour until the temperature reached 25°C. Filter with G4 size glass filter to obtain racemic rich catalyst with salt. The obtained solid is dissolved in Dichloromethane, the filtrate is dried under reduced pressure, and washed once more with hexane to obtain a final catalyst precursor.

production example One:

The catalyst of the above formula was prepared by the following method.

Add 7-tert-butylphenyl-2-isopropylindene (10.0 g, 34.4 mmol) to a 250 mL Schlenk flask and dry under reduced pressure. After dilution with anhydrous diethyl ether (172 mL) under an argon atmosphere, n-BuLi 2.5 M in hexane (36.2 mmol, 14.5 mL) is slowly added at -25°C. After stirring at 25°C for more than 4 hours, Et2SiCl2 (34.4 mmol, 5.15 mL) was added to the reaction mixture, followed by stirring at 25°C overnight. After drying all of the solvent, hexane is added to dilute it, and then LiCl is filtered using a G4 size glass filter, and the filtrate is dried under reduced pressure. In another 250mL Schlenk flask, add 7-tert-butylphenyl-2-methylindene (9.04 g, 34.4 mmol) and CuCN (1.72 mmol, 0.15 g), and dry under reduced pressure. After dilution with anhydrous toluene (208 mL) and THF (20.4 mL) under an argon atmosphere, n-BuLi 2.5 M in hexane (36.2 mmol, 14.5 mL) was slowly added at -25°C, followed by stirring at 25°C overnight. Pour the above mono-Si solution into this flask. After that, it is stirred at 25°C overnight, extracted using water, and then dried.

Put tert-butylamine (10.7 mmol, 1.1 mL) in a 100 mL Schlenk flask, add Anhydrous toluene (11.8 mL), and THF (0.86 mL) under argon atmosphere, and dilute it. Then, at -25°C, n-BuLi 2.5 M in hexane (11.2) mmol, 4.48 mL) is added slowly. After stirring at 25°C for 2 hours or more, it was added to another schlenk flask containing ZrCl ₄ ·2THF (4.03 g, 10.7 mmol) and toluene (9.3 mL) at -25°C and stirred at 25°C for 2 hours or more. Add UT2 Ligand (6.81 g, 10.7 mmol) to another 100 mL Schlenk flask and dry under reduced pressure. After dilution with anhydrous toluene (16.0 mL) and THF (1.60 mL) under an argon atmosphere, n-BuLi 2.5 M in hexane (22.5 mmol, 9.00 mL) is slowly added at -25°C. After stirring at 25℃ for 2 hours or more, the Zr-tert-butylamide solution synthesized above is added at -25℃. After overnight stirring at 25°C, HCl 1.0 M in diethyl ether (23.5 mmol, 23.5 mL) was added at -25°C and stirred for about 1 hour until the temperature reached 25°C. After filtering with a G4 size glass filter, the filtrate is dried under reduced pressure. After dissolving the dried filtrate in hexane and stirring, the impurities are washed off, and the racemic catalyst precursor is separated using dichloromethane and hexane to obtain it.

production example 2: Preparation of supported catalyst

In a 3 L reactor, 150 g of silica and 10 wt% of methylaluminoxane (1214 g) were put and reacted at 95° C. for 24 hours. After precipitation, the upper layer was removed and washed twice with toluene. The transition metal compound (9.6 g) of Comparative Preparation Examples 1 to 3 or Preparation Example 1 was diluted in toluene and added to the reactor, followed by reaction at 50° C. for 5 hours. When the precipitation is completed after the reaction is completed, the upper layer solution is removed, the remaining reaction product is washed with toluene, washed again with hexane, and 4.5 g of Atmer 163 antistatic agent is added, filtered and vacuum dried to form silica-supported metallocene catalyst in the form of solid particles 250 g were obtained.

comparative example One:

In the presence of the silica-supported metallocene catalyst prepared in Preparation Example 2 using the catalyst of Comparative Preparation Example 1, bulk-slurry polymerization of propylene was performed using two continuous loop reactors.

At this time, triethylaluminum (TEAL) and hydrogen gas were added at a content of 50 ppm and 300 ppm using a pump, respectively, and 16.7 wt of a supported catalyst obtained using the transition metal compound of Comparative Preparation Example 1 for bulk-slurry polymerization % was used in the form of a mud catalyst mixed with oil and grease. The reactor was operated at a temperature of 70° C. and an hourly output of about 40 kg.

The propylene input amount was 85 kg/h to prepare homo polypropylene through the polymerization process.

comparative example 2:

In the presence of the silica-supported metallocene catalyst prepared in Preparation Example 2 using the catalyst of Comparative Preparation Example 2, bulk-slurry polymerization of propylene was performed using two continuous loop reactors.

At this time, triethylaluminum (TEAL) and hydrogen gas were added at a content of 50 ppm and 370 ppm using a pump, respectively, and 16.7 wt% of the supported catalyst obtained using the transition metal compound of Comparative Preparation Example 2 for bulk-slurry polymerization It was used in the form of a mud catalyst mixed with oil and grease so that the content of The reactor was operated at a temperature of 70° C. and an hourly output of about 37 kg.

The propylene input amount was 84 kg/h to prepare homopolypropylene through the polymerization process.

comparative example 3:

In the presence of the silica-supported metallocene catalyst prepared in Preparation Example 2 using the catalyst of Comparative Preparation Example 2, bulk-slurry polymerization of propylene was performed using two continuous loop reactors.

At this time, triethylaluminum (TEAL) and hydrogen gas were added in an amount of 50 ppm and 550 ppm using a pump, respectively, and 16.7 wt% of the supported catalyst obtained using the transition metal compound of Comparative Preparation Example 2 for bulk-slurry polymerization It was used in the form of a mud catalyst mixed with oil and grease so that the content of The temperature of the reactor was 70° C., and the hourly production was operated at about 38 kg.

The propylene input amount was 82 kg/h to prepare homo polypropylene through the polymerization process.

comparative example 4:

In the presence of the silica-supported metallocene catalyst prepared in Preparation Example 2 using the catalyst of Comparative Preparation Example 3, bulk-slurry polymerization of propylene was performed using two continuous loop reactors.

At this time, triethylaluminum (TEAL) and hydrogen gas were added in an amount of 50 ppm and 110 ppm using a pump, respectively, and 16.7 wt% of the supported catalyst obtained using the transition metal compound of Comparative Preparation Example 3 for bulk-slurry polymerization It was used in the form of a mud catalyst mixed with oil and grease so that the content of The reactor was operated at a temperature of 70° C. and an hourly output of about 39 kg.

The propylene input amount was 83 kg/h to prepare homopolypropylene through the polymerization process.

comparative example 5:

In the presence of the silica-supported metallocene catalyst prepared in Preparation Example 2 using the catalyst of Comparative Preparation Example 3, bulk-slurry polymerization of propylene was performed using two continuous loop reactors.

At this time, triethylaluminum (TEAL) and hydrogen gas were added in an amount of 50 ppm and 900 ppm using a pump, respectively, and 16.7 wt% of the supported catalyst obtained using the transition metal compound of Comparative Preparation Example 3 for bulk-slurry polymerization It was used in the form of a mud catalyst mixed with oil and grease so that the content of The reactor was operated at a temperature of 70° C. and an hourly output of about 39 kg.

The propylene input amount was 83 kg/h to prepare homopolypropylene through the polymerization process.

Example One:

In the presence of the silica-supported metallocene catalyst prepared in Preparation Example 2 using the catalyst of Preparation Example 1, bulk-slurry polymerization of propylene was performed using two continuous loop reactors.

At this time, triethylaluminum (TEAL) and hydrogen gas were added at a content of 50 ppm and 180 ppm using a pump, respectively, and 16.7 wt% of the supported catalyst obtained using the transition metal compound of Comparative Preparation Example 3 for bulk-slurry polymerization It was used in the form of a mud catalyst mixed with oil and grease so that the content of The reactor was operated at a temperature of 70° C. and an hourly output of about 40 kg.

The propylene input amount was 81 kg/h to prepare homopolypropylene through the polymerization process.

Example 2:

Prepared in Preparation Example 2 using the catalyst of Preparation Example 1 In the presence of a silica-supported metallocene catalyst, bulk-slurry polymerization of propylene was carried out using two continuous loop reactors.

At this time, triethylaluminum (TEAL) and hydrogen gas were added at a content of 50 ppm and 70 ppm using a pump, respectively, and 16.7 wt of a supported catalyst obtained using the transition metal compound of Comparative Preparation Example 3 for bulk-slurry polymerization % was used in the form of a mud catalyst mixed with oil and grease. The reactor was operated at a temperature of 70° C. and an hourly output of about 40 kg.

The propylene input amount was 81 kg/h to prepare homopolypropylene through the polymerization process.

test example

First, the 13C NMR analysis results of the homo polypropylene of Example 1 and Comparative Example 2 are shown in FIG. 1 . Referring to FIG. 1 , in Example 1, PEAK that appears when four or more -CH ₂ - is continuous in the PP polymer chain was confirmed, thereby confirming the formation of LCB, and in Comparative Example 2, this PEAK was not confirmed.

In addition, the catalyst activity in Examples 1 and 2 and Comparative Examples 1 to 5 in each polymerization step was evaluated and shown in Table 1 below.

And, according to Examples 1 and 2 and Comparative Examples 1 to 5, the homopolymerization process and the polypropylene obtained therefrom were evaluated for physical properties in the following manner. The results are shown in Table 1 below.

(1) Melt index (MI, 2.16 kg): Measured at 230 ° C. under a load of 2.16 kg according to ASTM D1238, and expressed as the weight (g) of the polymer melted for 10 minutes.

(2) Weight average molecular weight (Mw) and molecular weight distribution (MWD, polydispersity index) of the polymer: The weight average molecular weight (Mw) and number average of the polymer using gel permeation chromatography (GPC: gel permeation chromatography, manufactured by Waters) Molecular weight (Mn) was measured, and molecular weight distribution (PDI) was calculated by dividing the weight average molecular weight by the number average molecular weight. At this time, the analysis temperature was 160 ℃, the solvent was trichlorobenzene, and the molecular weight was measured by standardizing with polystyrene.

The results of measuring the molecular weight distribution of the homo polypropylene of Example 1 and Comparative Examples 1 to 3 as GPC are shown in FIG. 2 , and the Mw/MWD measurement results of each Example and Comparative Example are shown in Table 1.

(3) Measurement of residual stress ratio

For the homo polypropylene according to the Examples and Comparative Examples, each sample was taken and a strain of 200% was applied at 235° C., and then the change in residual stress was measured for 10 minutes.

A Discovery Hybrid Rheometer (DHR) manufactured by TA Instruments was used to measure the residual stress, and the sample was sufficiently loaded between the upper and lower plates with a diameter of 25 mm, melted at 235° C., and then the gap was fixed at 1 mm for measurement.

Based on the measured residual stress data, the ratio of residual stress (RS%) was calculated according to Equation 1 below:

[Formula 1]

Residual stress ratio (Y) = (RS ₁ /RS ₀ )*100

In Equation 1, RS ₀ is the residual stress at 0.02 seconds (t ₀ ) after applying 200% strain to the synthetic resin sample under 235 ° C., and RS ₁ is 200% strain applied to the synthetic resin sample under 235 ° C. It is the residual stress at 1.00 second (t ₁ ) after.

The results of measuring the residual stress and residual stress ratio for the homo polypropylene of Example 1 and Comparative Examples 1 to 3 are shown in FIG. 4, and the residual stress ratio measurement results of each Example/Comparative Example are shown in Table 1.

(4) Complex viscosity according to each rate: The complex viscosity according to each rate was obtained by dynamic frequency sweep at 190°C using an advanced rheometric expansion system (ARES). The dynamic frequency sweep was measured using a disk-shaped 25 mm parallel plate.

The results of measuring the composite viscosity for each speed for the homo polypropylene of Example 1 and Comparative Examples 1 to 3 are shown in FIG. 3, and the composite viscosity at each speed of 1 rad/s in each Example/Comparative Example, Table 1 shows the composite viscosity measurement results at each speed of 100 rad/s.

melt index
(g/10min) catalytic activity
(kg/g-cat) Mw Mwd Complex Viscosity
(1 rad/s; Pa s)
Complex Viscosity
(100 rad/s; Pa s) residual stress
ratio(%) Comparative Example 1 28.0 27.3 169,000 2.87 420 207 0.148 Comparative Example 2 32.0 27.0 160,000 2.40 336 223 0.021 Comparative Example 3 26.0 26.6 166,000 2.40 408 243 0.043 Comparative Example 4 79 8.0 201,000 2.59 472 248 0.168 Comparative Example 5 1463 6.7 53,000 2.50 N.D. N.D. N.D. Example 1 28.0 23.7 171,000 2.30 494 210 0.399 Example 2 9 11.0 250,000 2.30 540 253 0.286

N.D.: not measurable

In Examples 1 and 2, while the polymerization activity equal to or higher than that of Comparative Examples was expressed, the finally formed homo polypropylene had a higher residual stress ratio, a high complex viscosity at 1 rad/s, a narrow molecular weight distribution, and a similar melt index. It was confirmed to exhibit a low composite viscosity at 100 rad/s.

Therefore, it was confirmed that the homopolypropylene of Example exhibited excellent mechanical properties and excellent processability as a molded article in injection molding and the like compared to Comparative Example.

Claims (11)

Homo polypropylene that meets the following conditions:
i) molecular weight distribution 1.5 to 2.35 or less
ii) Residual stress ratio 0.25% to 0.5%
iii) a complex viscosity of 450 to 600 Pa·s at an angular rate of 1 rad/s, and a complex viscosity of 200 to 300 Pa·s at an angular rate of 100 rad/s.
The homopolypropylene according to claim 1, having a melt index (measured at 230°C with a load of 2.16 kg according to ASTM D1238) of 5 to 3000 g/min.
The homo polypropylene according to claim 1, wherein the weight average molecular weight is 30000 to 300000 g/mol.
silica carrier; And in the presence of a supported catalyst including a supported catalyst including a compound of Formula 1 and a cocatalyst supported on a silica carrier, the method for producing the homopolypropylene of claim 1, comprising the step of polymerizing a propylene monomer:
[Formula 1]

In Formula 1,
X ₁ and X ₂ are each independently halogen,
R ₁ and R ₅ are each independently C _6-20 aryl substituted with C _1-20 alkyl;
R ₂ to R ₄ and R ₆ to R ₈ are each independently hydrogen, halogen, C _1-20 alkyl, C _2-20 alkenyl, C _1-20 alkylsilyl, C _1-20 silylalkyl, C _1-20 alkoxysilyl, C _1-20 ether, C _1-20 silylether, C _1-20 alkoxy, C _6-20 aryl, C _7-20 alkylaryl, or C _7-20 arylalkyl;
A is carbon, silicon or germanium.
5. The method of claim 4,
The R ₁ and R ₅ are each independently a phenyl group substituted with a C _3-6 branched chain alkyl group, the method for producing a homopolypropylene.
5. The method of claim 4,
Wherein R ₁ and R ₅ are each tert-butyl phenyl, a method for producing a homopolypropylene.
5. The method of claim 4,
The A is silicone, a method for producing a homopolypropylene.
5. The method of claim 4,
The compound of Formula 1 is a compound represented by the following Formula 1a, a method for producing a homopolypropylene.
[Formula 1a]

5. The method of claim 4,
The co-catalyst is a method for producing a homo polypropylene comprising a compound represented by the following formula (2):
[Formula 2]
-[Al(R ₁₁ )-O] _m -
In Formula 2,
R ₁₁ may be the same as or different from each other, and each independently halogen; C _1-20 hydrocarbons; or a C1-20 hydrocarbon substituted with halogen;
m is an integer greater than or equal to 2;
[Claim 5] The method of claim 4, wherein the supported catalyst further comprises an antistatic agent.
A molded article comprising the homo polypropylene according to any one of claims 1 to 3 .

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