KR20150052803A - Polypropylene - Google Patents

Abstract

The present invention relates to polypropylene which has a narrow distribution of molecular weight and a small eruption amount of a low molecular weight, thereby being environmentally friendly. According to the present invention, propylene is polymerized by using a new metallocene compound having an excellent polymerization activation and a hydrogen reactivity, thereby easily controlling physical properties of polypropylene and obtaining polypropylene with excellent physical properties.

Description

Polypropylene {Polypropylene}

The present invention relates to polypropylene. More particularly, the present invention relates to a process for producing polypropylene using a catalyst containing a novel metallocene compound for producing an environmentally friendly polypropylene having a narrow molecular weight distribution and a small amount of elution of low molecular weight.

Dow has announced the early 1990s [Me ₂ Si (Me ₄ C ₅ ) NtBu] TiCl ₂ (hereinafter abbreviated as CGC) (U.S. Patent No. 5,064,802) - In the copolymerization of olefins, the CGC is superior to conventional metallocene catalysts in two major ways: (1) high molecular weight polymers with high activity even at high polymerization temperatures; , And (2) the copolymerization of alpha-olefins with large steric hindrance such as 1-hexene and 1-octene is also excellent. In addition, various characteristics of CGC were gradually known during the polymerization reaction, and efforts to synthesize the derivative and use it as a polymerization catalyst have actively been made in academia and industry.

A Group 4 transition metal compound having one or two cyclopentadienyl groups as ligands can be activated with methylaluminoxane or a boron compound to be used as a catalyst for olefin polymerization. These catalysts exhibit unique properties that conventional Ziegler-Natta catalysts can not achieve.

That is, the polymer obtained using such a catalyst has a narrow molecular weight distribution and better reactivity with the second monomer such as alpha olefin or cyclic olefin, and the second monomer distribution of the polymer is uniform. Further, by changing the substituent of the cyclopentadienyl ligand in the metallocene catalyst, the stereoselectivity of the polymer can be controlled when the alpha olefin is polymerized, and the degree of copolymerization, the molecular weight, and the molecular weight of the second monomer Distribution and the like can be easily controlled.

On the other hand, since metallocene catalysts are more expensive than conventional Ziegler-Natta catalysts, they are economically worthy of good activity.

A number of researchers have studied various catalysts, and it has generally been found that the bridged catalyst is more reactive to the second monomer. The bridged catalyst studied so far can be roughly classified into three types according to the bridge type. One is a catalyst in which two cyclopentadienyl ligands are linked by an alkylene di-bridge through the reaction of an electrophile such as an alkyl halide with indene or fluorene, the second is a silicon bridged catalyst connected by -SiR ₂ - Is a methylene bridged catalyst obtained from the reaction of fulvene with indene or fluorene.

However, among the above attempts, the catalysts actually applied to commercial plants are few, and the production of catalysts showing improved polymerization performance is still required.

In addition, when the metallocene compound is applied to a commercial commercialized gas phase and slurry plant, the carrier is supported. Studies have been made to carry out co-catalysis at the same time to carry out the catalytic reaction and to exhibit activity without addition of additional co-catalyst during the polymerization process. However, if a non-homogeneous catalyst is prepared by carrying out basically, The activity becomes lower than that of the homogeneous catalyst.

US Patent No. 5,064,802

The present invention provides a process for producing polypropylene using a catalyst comprising a polypropylene which is environment-friendly and has a narrow molecular weight distribution and a low molecular weight elution amount and a novel metallocene compound for producing the polypropylene.

The present invention provides a polypropylene having a molecular weight distribution (MWD) of 3.0 or less and a TVOC of 40 ppm or less.

The polypropylene obtained by the process for producing polypropylene according to the present invention has a narrow molecular weight distribution and a small amount of elution of low molecular weight and is eco-friendly, so that it can be used for various purposes.

Hereinafter, polypropylene according to a specific embodiment of the present invention will be described in more detail. It is to be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

In addition, throughout this specification, "comprising" or "containing ", unless specifically stated, refers to including any and all components (or components) Can not be interpreted as excluding.

According to one aspect of the present invention, polypropylene having a molecular weight distribution (MWD) of 3.0 or less and a TVOC of 40 ppm or less is provided.

The inventors of the present invention have confirmed that polypropylene having a narrow molecular weight distribution and low TVOC can be produced by using a catalyst containing a novel metallocene compound to be described later and completed the invention.

Particularly, since the polypropylene has a narrow molecular weight distribution of about 3.0 or less, preferably about 2.5 or less, it is possible to produce a product having high transparency and little flavor and odor problem specific to polypropylene.

In addition, the polypropylene may have a TVOC value of about 40 ppm or less, preferably about 10 to about 30 ppm, and more preferably about 20 to 30 ppm. The TVOC can be measured with a P & T-GC / MS apparatus as a physical property of volatile organic compounds emitted from the polymer. When the TVOC value is low, the amount of low molecular leaching is small and environmentally friendly. When TVOC value is high, And the like.

Such The polypropylene can be used as a packaging container, a film, a sheet, an injection molded product, a fiber product and the like which have a narrow molecular weight distribution and an excellent flowability.

The polypropylene of the above embodiment may have a weight average molecular weight (Mw) of about 10,000 to about 400,000 g / mol, and preferably about 50,000 to about 300,000 g / mol.

The xylene solubles (Xs) of the polypropylene exhibit a high tacticity of about 3.0 wt% or less, preferably about 2.5 wt% or less, and more preferably about 2.0 wt% or less. The xylene solubles are the content (% by weight) of the copolymer soluble in the cooled xylene determined by dissolving the polypropylene in xylene and crystallizing the insoluble portion from the cooling solution. The xylene solubles contain polymer chains of low stereoregularity, and the lower the content of the xylene solubles, the higher the stereoregularity.

The polypropylene may have a SPAN value measured by an optical diffraction particle size analyzer of about 3.0 or less, preferably 2.0 or less, more preferably 1.0 or less. The SPAN value means the width of the particle size distribution diagram. The polypropylene has a SPAN value of 3.0 or less and a uniform particle size.

On the other hand, the polypropylene can be prepared by polymerizing propylene in the presence of a catalyst comprising a metallocene compound represented by the following formula (1): < EMI ID =

[Chemical Formula 1]

In Formula 1,

M ¹ is a Group 3 transition metal, a Group 4 transition metal, a Group 5 transition metal, a lanthanide series transition metal or an ethanide series transition metal;

X is the same or different halogen;

A is a bridge group connecting an indenyl group as an element of Group 14;

R ¹ is alkyl, alkenyl, alkylaryl, arylalkyl or aryl of 1 to 20 carbon atoms;

R ² is hydrogen, alkyl of 1 to 20 carbon atoms, alkenyl, alkylaryl, arylalkyl or aryl;

R ³ , R ^{3 '} , R ⁴ , and R ^4' are the same or different from each other and are each an alkyl, alkenyl, alkylaryl, arylalkyl, or aryl having 1 to 20 carbon atoms;

n is an integer of 1 to 20;

Preferably, R ¹ and R ² in the general formula (1) are each alkyl having 1 to 4 carbon atoms; R ³ and R ^{3 '} are each alkyl, alkenyl, or arylalkyl having 1 to 20 carbon atoms; R ⁴ and R ^{4 '} are each aryl or alkylaryl of 1 to 20 carbon atoms; n is an integer from 1 to 6; A may be silicon (Si).

The metallocene compound of Formula 1 has two indenyl groups in which a substituent other than hydrogen is introduced at the 2-position and the 4-position as a ligand, and in particular, a bridge group group is substituted with a functional group capable of acting as a Lewis base as an oxygen-donor, thereby maximizing the activity as a catalyst. And exhibits high polymerization activity even when carried on a carrier. Accordingly, when the compound of Formula 1 is supported on its own or on a carrier and used as a catalyst in the production of polyolefins, a polyolefin having desired properties can be more easily produced.

According to one embodiment of the present invention, the metallocene compound represented by Formula 1 may be used alone or as a supported catalyst supported on a support together with a cocatalyst in a method for producing polypropylene. The cocatalyst may include an alkylaluminoxane-based cocatalyst, and a boron-based cocatalyst.

The carrier may be any of those generally used in the technical field to which the present invention belongs, so that it is not particularly limited, but preferably at least one carrier selected from the group consisting of silica, silica-alumina and silica-magnesia may be used. On the other hand, when supported on a carrier such as silica, since the silica carrier and the functional group of the metallocene compound are chemically bonded and supported, there is almost no catalyst liberated from the carrier surface in the olefin polymerization process, There is an advantage that no fouling occurs in which the wall surface of the reactor or the polymer particles are entangled with each other during the production.

The polypropylene produced in the presence of a supported catalyst containing such a carrier is excellent in particle shape and apparent density of the polymer and can be suitably used in conventional slurry polymerization or bulk polymerization or gas phase polymerization processes.

Therefore, it is preferable to use a carrier which is dried at a high temperature and has a siloxane group having high reactivity on the surface. Specifically, silica, silica was dried at high temperature - can be used are alumina and the like, which are typically _{Na 2 O, K 2 CO 3} , BaSO 4, Mg (NO 3) an oxide of _2, such as carbonate, sulfate, nitrate component .

According to one embodiment of the present invention, the metallocene compound represented by Formula 1 may be used as a catalyst for polymerization of propylene together with an alkylaluminoxane-based co-catalyst and a boron-based co-catalyst.

The alkylaluminoxane-based co-catalyst may be represented by the following formula (2).

(2)

In Formula 2,

M ² is a Group 13 metal element;

R ⁵ are the same or different and are each an alkyl, alkenyl, alkylaryl, arylalkyl or aryl having 1 to 20 carbon atoms;

m may be an integer of 2 or more.

The alkylaluminoxane-based promoter is preferably a compound wherein R ⁵ in the above formula 2 is methyl, ethyl, propyl, isopropyl, isopropenyl, n- butyl (n-butyl), sec- butyl (sec -butyl), tert- butyl (tert -butyl), pentyl (pentyl), hexyl (hexyl), octyl (octyl), decyl (decyl), dodecyl (dodecyl) Tridecyl, tetradecyl, pentadecyl, hexadecyl, octadecyl, eikosyl, dokosyl, tetrakosyl, cyclododecyl, cyclohexyl, Cyclohexyl, cyclooctyl, phenyl, tolyl, or ethylphenyl; M ² may be aluminum.

In Formula 2, m may be an integer of 2 or more, or an integer of 2 to 500, preferably 6 or more, or an integer of 6 to 300, more preferably 10 or more, or an integer of 10 to 100 .

The alkylaluminoxane-based co-catalyst may be a compound capable of acting as a Lewis acid capable of forming a bond through a Lewis acid-base interaction with a functional group introduced into a bridge group of the metallocene compound of Formula 1 And a metal element. The promoter compound of Formula 2 may exist in a linear, circular or network form. Examples of the promoter compound include at least one of methyl aluminoxane, ethyl aluminoxane, propyl aluminoxane and butyl aluminoxane. have.

In the catalyst for polypropylene polymerization of the present invention, a co-catalyst containing a non-conjugated anion as a non-alkylaluminoxane-based catalyst may be used in addition to the alkylaluminoxane-based co-catalyst. In particular, according to an embodiment of the present invention, a boron-based promoter may be used as the non-alkylaluminoxane-based co-catalyst.

The boron-based promoter may be selected from the group consisting of dimethylanilinium tetrakis (pentafluorophenyl) borate, [HN (CH ₃ ) ₂ C ₆ H ₅ ] [B (C ₆ F ₅ ) ₄ ] ), Trityl tetakis (pentafluorophenyl) borate, [(C ₆ H ₅ ) ₃ C] [B (C ₆ F ₅ ) ₄ ]), and methyl anilinium tetrakis (Pentafluorodiphenyl) borate, [HN (CH ₃ ) (C ₆ H ₅ ) ₂ ] [B (C ₆ F ₅ ) ₄ ] Can be used.

The boron-based promoter enables stabilization of the metallocene compound to maintain activity in the polymerization. In particular, the metallocene compound used in the present invention has a tether, and leaching phenomenon does not occur due to the functional group, so that fouling does not occur and excellent activity can be exhibited. However, if there is no tether such as a known metallocene compound, there is a problem that fouling occurs mostly due to reaction with a leached catalyst precursor and a boron-based co-catalyst.

In the method for producing polypropylene according to the present invention, two promoters of an alkyl aluminoxane co-catalyst and a non-alkyl aluminoxane-based boron co-catalyst may be simultaneously carried to form a supported catalyst having improved activity. Also, the co-catalysts which did not cause adverse effects between the two co-catalysts were selected, and the optimum supporting ratio was confirmed through experiments.

The metallocene compound may be supported in an amount ranging from about 40 to about 240 μmol, preferably from about 80 to about 160 μmol, based on 1 g of silica, per weight of carrier.

In addition, the alkylaluminoxane-based cocatalyst may be supported in an amount of about 8 to about 25 mmol, preferably about 10 to about 20 mmol, based on 1 g of silica per weight of carrier, for example, 1 g of silica.

The boron based promoter may be supported in an amount ranging from about 50 to about 300 μmol, preferably about 64 to about 240 μmol, based on 1 g of silica per weight of carrier, based on 1 g of silica.

The catalyst has an improved catalytic activity over the supported catalyst having one kind of promoter, and even if the supporting condition of the metallocene compound is changed, that is, the reaction temperature, the reaction time, the type of silica and the loading amount of the metallocene compound The polypropylene can be produced with improved activity.

Here, the polymerization of propylene can be carried out by reacting at a temperature of about 25 to about 500 DEG C and a pressure of about 1 to about 100 kgf / cm < ² > for about 1 to about 24 hours. At this time, the polymerization reaction temperature is preferably about 25 ° C to about 200 ° C, and more preferably about 50 ° C to about 100 ° C. Further, the polymerization reaction pressure is preferably about 1 to about 70 kgf / cm ² , more preferably about 5 to about 50 kgf / cm ² . The polymerization reaction time is preferably about 1 to about 5 hours.

The polypropylene may be carried out by contacting propylene with a catalyst containing the metallocene compound represented by the general formula (1).

Further, according to one embodiment of the present invention, the polymerization of propylene can be carried out under hydrogen gas.

At this time, the hydrogen gas activates the inactive sites of the metallocene catalyst and causes a chain transfer reaction to control the molecular weight. The metallocene compound of the present invention is excellent in hydrogen reactivity, and therefore, polypropylene having a desired molecular weight distribution can be effectively obtained by controlling the amount of hydrogen gas used in the polymerization process.

The hydrogen gas may be added in an amount of about 10 to about 3000 ppm, preferably about 10 to about 2000 ppm, based on the total content of propylene. The molecular weight distribution and the melt flow rate (MFR) of the polypropylene to be produced can be controlled within a desired range by controlling the amount of the hydrogen gas to be used while exhibiting sufficient catalytic activity. Accordingly, Polypropylene can be produced.

The polypropylene can be carried out by a solution polymerization process, a slurry process or a gas phase process using one continuous slurry polymerization reactor, a loop slurry reactor, a gas phase reactor or a solution reactor, and the like.

The catalyst may be an aliphatic hydrocarbon solvent having 5 to 12 carbon atoms suitable for the polymerization of olefin monomers such as pentane, hexane, heptane, nonane, decane, isomers thereof and aromatic hydrocarbon solvents such as toluene and benzene, Methane, chlorobenzene, or the like, or injected by dilution. It is preferable to use a small amount of water or air, which acts as a catalyst poison, by using a small amount of alkylaluminum.

In the present invention, matters other than those described above can be added or subtracted as needed, and therefore, the present invention is not particularly limited thereto.

Hereinafter, preferred embodiments of the present invention will be described in order to facilitate understanding of the present invention. However, the following examples are provided only for the purpose of easier understanding of the present invention, and the present invention is not limited thereto.

< Example  >

< Synthetic example : Metallocene  Synthesis of Compound &gt;

Synthetic example : &Lt; EMI ID = Metallocene  Synthesis of compounds

(3)

Step 1: (6-t- Butoxyhexyl ) Of dichloromethylsilane  Produce

100 mL of a solution of t-butoxyhexyl magnesium chloride (about 0.14 mol, ether) was added dropwise to 100 mL of a trichloromethylsilane solution (about 0.21 mol, hexane) at -100 ° C over 3 hours, And stirred for 3 hours.

After separating the transparent organic layer from the mixed solution, the separated transparent organic layer was vacuum dried to remove excess trichloromethylsilane. Thus, a transparent liquid (6-t-butoxyhexyl) dichloromethylsilane was obtained (yield: 84%).

^{1 H NMR (500 MHz, CDCl} 3, 7.24 ppm): 0.76 (3H, s), 1.11 (2H, t), 1.18 (9H, s), 1.32 ~ 1.55 (8H, m), 3.33 (2H, t)

Step 2: (6-t- Butoxyhexyl ) ( methyl ) - Bis (2-methyl-4-phenylindenyl) silane  Produce

15.4 mL of n-butyllithium solution (2.5 M, hexane solvent) was slowly added dropwise to 77 mL of 2-methyl-4-phenylindene toluene / THF = 10/1 solution (34.9 mmol) The mixture was stirred for 1 hour and then at room temperature for one day. Subsequently, 5 g of the (6-t-butoxyhexyl) dichloromethylsilane prepared previously was slowly added dropwise to the mixed solution at -78 ° C, and the mixture was stirred for about 10 minutes and then at 80 ° C for 1 hour. The organic layer was separated by adding water, purified silica column, and vacuum dried to obtain a sticky yellow oil (racemic: meso = 1: 1) in a yield of 78%.

¹ H NMR (500 MHz, CDCl ₃ , 7.24 ppm): 0.10 (3H, s), 0.98 (2H, t), 1.25 (9H, s), 1.36-1.50 , 2.26 (6H, s), 3.34 (2H, t), 3.81 (2H, s), 6.87 7.53 (4 H, t), 7.61 (4 H, d)

Step 3: Preparation of [(6-t- Butoxyhexylmethylsilane - Dill ) -Bis (2- methyl -4- Phenyl indenyl )] Zirconium Dichloride  Produce

To a solution of the above-prepared (6-t-butoxyhexyl) (methyl) bis (2-methyl-4-phenyl) indenylsilane ether / hexane = 1/1 solution (3.37 mmol) in n-butyl lithium M in hexane) was slowly added dropwise at -78 ° C, stirred at room temperature for about 2 hours, and then vacuum-dried. Then, the salt was washed with hexane, followed by filtration and vacuum drying to obtain a yellow solid. The ligand salt synthesized in a glove box and 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 weighed in a Schlenk flask, ether was slowly added dropwise at -78 ° C., And stirred for one day. Thereafter, the red reaction solution was separated by filtration, 4 equivalents of an HCl ether solution (1M) was slowly added dropwise at -78 ° C, and the mixture was stirred at room temperature for 3 hours. After filtration and vacuum drying, the metallocene compound of orange solid component was obtained in a yield of 85% (racemic: meso = 10: 1).

^{1 H NMR (500 MHz, C} 6 D 6, 7.24 ppm): 1.19 (9H, s), 1.32 (3H, s), 1.48 ~ 1.86 (10H, m), 2.25 (6H, s), 3.37 (2H, d), 7.67 (2H, d), 7.63 (2H, d), 6.95

compare Synthetic example : Metallocene  Synthesis of compounds

[Chemical Formula 4]

Stage 1: Dimethylbis (2-methyl-4-phenylindenyl) silane  Produce

21.8 mL of n-butyllithium solution (2.5 M, hexane solvent) was slowly added dropwise to 77 mL of 2-methyl-4-phenylindene toluene / THF = 10/1 solution (49.5 mmol) at 0 ° C, The mixture was stirred for 1 hour and then at room temperature for one day. Thereafter, 2.98 mL of dichloromethylsilane was slowly added dropwise at 0 DEG C or lower, stirred for about 10 minutes, then heated to 80 DEG C and stirred for 1 hour. The organic layer was separated by adding water, and the silica column was purified and vacuum dried to obtain a sticky yellow oil (yield: racemic: meso = 1: 1).

^{1 H NMR (500 MHz, CDCl} 3, 7.24 ppm): 0.02 (6H, s), 2.37 (6H, s), 4.00 (2H, s), 6.87 (2H, t), 7.38 (2H, t), 7.45 (2H, t), 7.57 (4H, d), 7.65 (4H, t), 7.75

Step 2: Preparation of [dimethylsilanediylbis (2- methyl -4- Phenyl indenyl )] Zirconium Dichloride  Produce

10.9 mL of a n-butyllithium solution (2.5 M in hexane) was slowly added dropwise to 240 mL of a dimethyl bis (2-methyl-4-phenylindenyl) silane ether / hexane = 1/1 solution (12.4 mmol) Respectively. Thereafter, the mixture was stirred at room temperature for one day, filtered and vacuum dried to obtain a pale yellow solid. The ligand salt synthesized in a glove box and bis (N, N'-diphenyl-1,3-propanediamido) dichloro zirconium bis (tetrahydrofuran) were dissolved in a Schlenk flask ), Ether was slowly added dropwise at -78 ° C, and the mixture was stirred at room temperature for one day. The red solution was separated by filtration, dried in vacuo, and a toluene / ether = 1/2 solution was added to obtain a clear red solution. 1.5-2 equivalent of HCl ether solution (1M) was slowly added dropwise at -78 deg. C, followed by stirring at room temperature for 3 hours. After filtration and vacuum drying, the catalyst of orange solid component was obtained in a yield of 70% (racemic only).

^{1 H NMR (500 MHz, C} 6 D 6, 7.24 ppm): 1.32 (6H, s), 2.24 (6H, s), 6.93 (2H, s), 7.10 (2H, t), 7.32 (2H, t) , 7.36 (2H, d), 7.43 (4H, t), 7.60 (4H, d), 7.64

< Manufacturing example  And Comparative Example : Preparation of Supported Catalyst>

Manufacturing example

After supporting methylaluminoxane on silica, the metallocene compound obtained in the above Synthesis Example was carried, and further boron-based promoter catalyst was supported to prepare a supported catalyst.

More specifically, 3 g of silica L203F was preliminarily weighed in a shrinking flask, and 40 mmol of methylaluminoxane (MAO) was added thereto, followed by reaction at 95 DEG C for 24 hours. After precipitation, the upper layer was removed and washed twice with toluene. 360 占 퐉 ol of the metallocene compound obtained in Synthesis Example 1 was dissolved in toluene, and the mixture was reacted at 75 占 폚 for 5 hours. After the completion of the reaction, the upper layer solution was removed and the remaining reaction product was washed with toluene. And 252 μmol of dimethylanilinium tetrakis (pentafluorophenyl) borate were reacted at 75 ° C for 5 hours. After completion of the reaction, the reaction mixture was washed with toluene, washed again with hexane, and vacuum-dried to obtain 5 g of silica-supported metallocene catalyst in the form of solid particles.

compare Manufacturing example

A supported catalyst was prepared in the same manner as the preparation example except that the metallocene compound obtained in Comparative Synthesis Example was used instead of the metallocene compound obtained in the above Synthesis Example.

< Example  And Comparative Example : Propylene polymerization>

Example  One

Propylene bulk-slurry polymerization was carried out using two continuous loop reactors. For the bulk - slurry polymerization, a mud catalyst was used in which 20 wt% of the catalyst prepared in the supported catalyst production example was mixed with oil and grease. The reactor was operated at a temperature of 70 ° C and a production rate of about 40 kg per hour. The detailed operating conditions are described in Table 1 below.

Example  2 to 8

In Example 1, the polymerization was carried out in the same manner as in Example 1, except that the amount of the catalyst and the amount of hydrogen charged were changed.

Comparative Example  1 to 3

In Example 1, propylene polymerization was carried out in the same manner as in Example 1, except that the supported catalyst obtained in Comparative Production Example was used and the detailed process conditions were changed.

The detailed operating conditions of Examples 1 to 8 and Comparative Examples 1 to 3 are summarized in Table 1 below.

Temperature
(° C) pressure
(kg / cm2) Catalyst input
(g / hr) Propylene feed
(kg / hr) TEAL input
(ppm) Hydrogen input amount
(ppm) Example 1 70 35     1.6 40 50 300 Example 2 70 35 1.7 40 50 450 Example 3 70 35 1.3 40 50 1100 Example 4 70 35 1.6 40 50 500 Example 5 70 35 1.5 40 50 400 Example 6 70 35 1.6 40 50 300 Example 7 70 35 1.8 40 50 200 Example 8 70 35 2.0 40 50 100 Comparative Example 1 70 35 1.6 40 50 300 Comparative Example 2 70 35 1.3 40 50 500 Comparative Example 3 70 35 1.3 40 50 1100

&Lt; Measurement method of physical properties of polymer &

(1) Melt index

Measured at 230 占 폚 under a load of 2.16 kg according to ASTM D1238, and expressed as the weight (g) of the polymer that has been melted for 10 minutes.

(2) Weight average molecular weight

The sample dissolved in TCB was heated up to 220 ° C and passed through a column tube at a rate of about 1.0 cc / min per sample to measure a relative molecular weight relative to a reference.

(3) Particle size

After injecting the sample into the hopper with the optical diffraction particle size analyzer (Symatec HELOS), the APS (Average Particle Size) and SPAN value were confirmed by setting the method in the range of 50 ~ 3500um.

(4) Xylene solubles (Xylene Soluble)

Xylene was added to the sample, and the sample was preheated by heating at 135 ° C for 1 hour and cooling for 30 minutes. 1ml / min from OminiSec (Viscotek FIPA) equipment. When the base line of RI, DP and IP was stabilized by flowing Xylene for 4 hours at the flow rate, the concentration and injection amount of the pretreated sample were written and the peak area was calculated.

(5) Total volatile organic compounds (TVOC)

The content of total volatile organic compounds was measured by P & T-GC / MS instrument at 220 ° C / 20min after placing 1 g of sample in a Pat tube and blocking with glass wool.

Melt Index
(g / 10 min) Weight average molecular weight Molecular weight distribution APS (占 퐉) SPAN Example 1 35 147,100 2.4 944 0.63 Example 2 71 142,700 2.5 912 0.77 Example 3 1500 70,820 2.2 884 0.84 Example 4 89 134,900 2.3 928 0.70 Example 5 50 160,600 2.0 921 0.64 Example 6 39 176,900 2.4 946 0.78 Example 7 16 203,600 2.4 922 0.67 Example 8 6.3 257,500 2.3 943 0.69 Comparative Example 1 34 151,200 3.2 923 0.96 Comparative Example 2 60 144,700 3.4 911 1.03 Comparative Example 3 1500 73,400 3.4 871 1.12

Xylene soluble fraction (wt%) TVOC (ppm) Example 1 0.82 26.5 Example 2 0.79 27.0 Example 3 0.81 27.0 Example 4 0.55 28.2 Example 5 0.80 26.5 Example 6 0.79 27.2 Example 7 0.77 26.8 Example 8 0.62 27.3 Comparative Example 1 0.92 41.5 Comparative Example 2 0.89 41.8 Comparative Example 3 0.95 42.1

As shown in Tables 2 to 3, the examples of the present invention have a narrow molecular weight distribution (MWD) of 3.0 or less and a low TVOC as compared with the comparative example, so that they are eco-friendly and have little flavor and odor problem specific to polypropylene It can be seen that there is a characteristic.

In addition, the polypropylene of the above-mentioned example exhibited odorless, low elution characteristics and high stereoregularity characteristics as compared with the comparative example, and showed low SPAN value, indicating that the particles had uniform characteristics have.

Claims (12)

Polypropylene having a molecular weight distribution (MWD) of 3.0 or less and a TVOC of 40 ppm or less.
The polypropylene of claim 1, wherein the weight average molecular weight (Mw) is from 10,000 to about 400,000 g / mol.
The polypropylene according to claim 1, wherein the xylene solubles (Xs) is 3.0 wt% or less.
The polypropylene according to claim 1, wherein the SPAN value measured by the light diffraction particle size analyzer is 3.0 or less.
The polypropylene according to claim 1, wherein the polypropylene is a polypropylene produced by polymerizing propylene in the presence of a catalyst comprising a metallocene compound represented by the following formula
[Chemical Formula 1]

In Formula 1,
M ¹ is a Group 3 transition metal, a Group 4 transition metal, a Group 5 transition metal, a lanthanide series transition metal or an ethanide series transition metal;
X is the same or different halogen;
A is a bridge group connecting an indenyl group as an element of Group 14;
R ¹ is alkyl, alkenyl, alkylaryl, arylalkyl or aryl of 1 to 20 carbon atoms;
R ² is hydrogen, alkyl of 1 to 20 carbon atoms, alkenyl, alkylaryl, arylalkyl or aryl;
R ³ , R ^{3 '} , R ⁴ , and R ^4' are the same or different from each other and are each an alkyl, alkenyl, alkylaryl, arylalkyl, or aryl having 1 to 20 carbon atoms;
n is an integer of 1 to 20;
6. The compound according to claim 5, wherein R &lt; ¹ &gt; and R &lt; ² &gt; are each alkyl having 1 to 4 carbon atoms; R ³ and R ^{3 '} are each alkyl, alkenyl, or arylalkyl having 1 to 20 carbon atoms; R ⁴ and R ^{4 '} are each aryl or alkylaryl of 1 to 20 carbon atoms; n is an integer from 1 to 6; And A is silicon (Si).
The polypropylene according to claim 5, wherein the catalyst is a supported catalyst in which the metallocene compound represented by Formula 1, the alkylaluminoxane-based co-catalyst, and the boron-based co-catalyst are carried on a carrier.
The polypropylene according to claim 7, wherein the alkylaluminoxane-based co-catalyst is at least one selected from the group consisting of methyl aluminoxane, ethyl aluminoxane, propyl aluminoxane, and butyl aluminoxane.
The method of claim 7, wherein the boron-based promoter is selected from the group consisting of dimethylanilinium tetrakis (pentafluorophenyl) borate, trityl tetrakis (pentafluorophenyl) borate, and methyl anilinium tetrakis (pentafluorodiphenyl ) &Lt; / RTI &gt; borate.
8. The polypropylene according to claim 7, wherein the support is at least one selected from the group consisting of silica, silica-alumina and silica-magnesia.
6. The polypropylene according to claim 5, wherein the polymerization of propylene is carried out by reacting at a temperature of 25 to 500 DEG C and a pressure of 1 to 100 kgf / cm &lt; ² &gt; for 1 to 24 hours.
The method of claim 5, wherein the polymerization of the propylene is a polypropylene which is carried out under hydrogen of from 10 to 3000ppm (H ₂₎ gas, based on the total content of propylene.