KR102559050B1 - Propylene-1-butene copolymer and method for preparing the same - Google Patents

Abstract

In the present invention, a propylene-1-butene copolymer that has excellent transparency and stiffness and a high flexural modulus, and is useful for the production of injection-molded products requiring excellent transparency and flexural modulus, and furthermore, injection-molded products with a thin thickness, and a method for producing the same are provided.

Description

Propylene-1-butene copolymer and its manufacturing method {PROPYLENE-1-BUTENE COPOLYMER AND METHOD FOR PREPARING THE SAME}

The present invention relates to a propylene-1-butene copolymer that has high stiffness and flexural modulus along with excellent transparency and is useful for injection molding, and a method for preparing 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, decreases, 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-based catalysts. In the case of the Ziegler-Natta catalyst, since it is a multi-site catalyst in which several active sites are mixed, the molecular weight distribution of the polymer is wide, and the comonomer composition distribution is not uniform, so there is a problem in that there is a limit to securing desired physical properties. In particular, when random copolymerization with butene is performed in the presence of a Ziegler-Natta catalyst to secure transparency, the flexural modulus is greatly reduced due to a decrease in crystal properties.

On the other hand, the metallocene catalyst is composed of a combination of a main catalyst composed of a transition metal compound and a cocatalyst composed of an organometallic compound composed mainly of aluminum. Such a catalyst is a single site catalyst as a homogeneous complex catalyst. It is possible to manufacture a polymer having a narrow molecular weight distribution and a uniform composition distribution of comonomers according to the characteristics of a single active site. In addition, the tacticity, copolymerization characteristics, molecular weight, and crystallinity of the polymer may be changed according to the modification of the ligand structure of the catalyst and the change of the polymerization conditions.

Therefore, it is required to develop a method for preparing polypropylene, which is particularly useful for injection molding, by using a metallocene-based catalyst and having high stiffness and flexural modulus along with excellent transparency.

An object of the present invention is to provide a propylene-1-butene copolymer having high stiffness and flexural modulus along with excellent transparency, and a method for producing the same.

Another object of the present invention is to provide a resin composition comprising the above propylene-1-butene copolymer and a method for preparing the same.

According to one embodiment of the present invention, there is provided a propylene-1-butene copolymer that satisfies the following conditions:

i) Melt index (MI; measured at 230°C with 2.16 kg load according to ASTM D1238): 50 g/10min or more

ii) Xylene soluble content: 1.0% by weight or less

iii) melting point (Tm): 130 to 155 ° C.

iv) Molecular weight distribution (MWD): 2.4 or less

v) 1-butene content: 0.5 to 5% by weight relative to the total weight of the copolymer.

In addition, according to another embodiment of the present invention, in the presence of a catalyst composition containing a transition metal compound represented by the following formula (1), hydrogen gas is introduced at 300 to 2500 ppm, and propylene monomer and 1-butene monomer are randomly copolymerized. Provided is a method for producing the above-described propylene-1-butene copolymer, comprising the step of:

[Formula 1]

In Formula 1,

X ₁ and X ₂ are the same as or different from each other, and are each independently halogen;

R ₁ and R ₅ are the same as or different from each other, and 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 the same as or _different from each other and 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;

R ₉ and R ₁₀ are the same as each other and are C _2-20 alkyl.

Also, according to another embodiment of the present invention, a polypropylene resin composition including the above-described propylene-1-butene copolymer and a nucleating agent is provided.

In addition, according to another embodiment of the invention, in the presence of a catalyst composition containing the transition metal compound of Formula 1, hydrogen gas is introduced at 300 to 2500 ppm, and propylene monomer and 1-butene monomer are randomly copolymerized to prepare a propylene-1-butene copolymer according to claim 1; And it provides a method for producing a resin composition comprising the step of extruding by adding a nucleating agent to the propylene-1-butene copolymer.

The propylene-1-butene copolymer according to the present invention has a high melt index and melting point, a low xylene soluble content and a narrow molecular weight distribution, so that it can exhibit excellent transparency and high stiffness and flexural modulus when applied to a resin composition for molding. As a result, it can be useful for manufacturing injection-molded products requiring excellent transparency and flexural modulus, and furthermore, thin-film type injection-molded products.

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 an embodied feature, step, component, or combination thereof exists, but one or more other features or steps, components, or combinations thereof.

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, a propylene-1-butene copolymer according to specific embodiments of the present invention, a method for preparing the same, and a resin composition including the copolymer will be described.

In the present invention, when preparing a copolymer by polymerization of a propylene monomer and a 1-butene monomer, a metallocene-based catalyst having a specific structure is used and polymerization conditions are controlled, thereby increasing the melt index and melting point of the prepared copolymer, and at the same time reducing the xylene soluble content and molecular weight distribution, thereby exhibiting excellent processability and high transparency and high rigidity. In addition, by improving the crystal structure in the copolymer, the isotacticity, which is the ratio of the isotactic structure, is increased, thereby significantly improving the flexural modulus.

Specifically, the propylene-1-butene copolymer according to one embodiment of the present invention satisfies the following conditions:

i) Melt index (MI; measured at 230°C with 2.16 kg load according to ASTM D1238): 50 g/10min or more

ii) Xylene soluble content: 1.0% by weight or less

iii) melting point (Tm): 130 to 155 ° C.

iv) Molecular weight distribution (MWD): 2.4 or less

v) 1-butene content: 0.5 to 5% by weight relative to the total weight of the copolymer.

More specifically, the propylene-1-butene copolymer according to one embodiment of the present invention is a random copolymer and has a melt index (MI) measured under a load of 2.16 kg at 230 ° C. according to ASTM D 1238 (American society for testing and materials) standard. Melt index (MI) is 50 g/10 min or more.

In general, the melt index can be adjusted by controlling the amount of hydrogen introduced during the polymerization process, and in the case of using a conventional Ziegler-Natta catalyst, a high content of hydrogen must be introduced in the polymerization step. However, in the present invention, it is easy to prepare a low molecular weight polymer by controlling the three-dimensional structure, shows excellent catalytic activity even without hydrogen input or reduced hydrogen input, uses a metallocene-based catalyst with excellent process stability, and controls the amount of hydrogen gas introduced into the polymerization reaction, so that the polymer produced can have a high MI value as described above. When the MI is less than 50 g/10 min during injection molding, there is a concern that processability may deteriorate due to an increase in processing pressure. However, since the propylene-1-butene copolymer according to the present invention has a melt index of 50 g/10 min or more, it may be more useful for injection molding. Considering the excellent effect of improving physical properties of the propylene-1-butene copolymer according to melt index control, the MI of the propylene-1-butene copolymer is more specifically 52 g/10 min or more, or 55 g/10 min or more, and 100 g/10 min or less, or 65 g/10 min or less.

In addition, as described above, the propylene-1-butene copolymer according to one embodiment of the present invention has a high MI, xylene solubles (Xs) of 1.0% by weight or less, and high tacticity.

In the present invention, the xylene soluble content is obtained by dissolving a propylene-1-butene copolymer in xylene and then cooling it, crystallizing the insoluble portion from the resulting cooling solution, and measuring the content (% by weight) of the soluble polymer in the cooled xylene determined. 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. The propylene-1-butene copolymer 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. The xylene soluble content can be controlled by controlling the type of catalyst used during production or the amount of comonomer. Considering the excellent effect of improving stiffness and flexural modulus by controlling the xylene soluble content, the propylene-1-butene copolymer may have a xylene soluble content of 0.1% by weight or more, or 0.5% by weight or more, and may be 0.7% by weight or less, or 0.6% by weight or less.

On the other hand, in the present invention, the xylene soluble content of the propylene-1-butene copolymer is pretreated by adding xylene to a sample of the propylene-1-butene copolymer, heating at 135 ° C. for 1 hour, cooling for 30 minutes, and then flowing xylene for 4 hours at a flow rate of 1 mL / min in OminiSec (Viscotek Co., Ltd. FIPA) equipment to stabilize the base line of RI, DP, and IP It can be measured by measuring the concentration of the pretreated sample and the amount of injection, and then calculating the peak area.

In addition, the propylene-1-butene copolymer has an optimized melting point (Tm) of 130 to 155° C. while satisfying the above MI and xylene soluble conditions. In order to exhibit sufficient processability required for injection molding, the melting point of the propylene-1-butene copolymer must be 130 ° C. or higher, and considering the minimum content of 1-butene for injection molding, the melting point of the propylene-1-butene copolymer must be 155 ° C. or lower.

More specifically, the melting point of the propylene-1-butene copolymer may be 135°C or higher, or 140°C or higher, or 142°C or higher, and 155°C or lower, or 153°C or lower, or 151°C or lower.

Meanwhile, in the present invention, the melting point of the propylene-1-butene copolymer can be measured using a Differential Scanning Calorimeter (DSC). Specifically, after increasing the temperature of the polymer to 200 ° C., maintaining it at that temperature for 5 minutes, then lowering it to 30 ° C., then increasing the temperature again, and measuring the peak of the DSC (Differential Scanning Calorimeter, manufactured by TA) curve 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 propylene-1-butene copolymer has a narrow molecular weight distribution (MWD) of 2.4 or less. By having such a narrow molecular weight distribution, rigidity is increased, so that excellent mechanical properties can be exhibited during the manufacture of various molded articles. More specifically, the propylene-1-butene copolymer may have a MWD of 2.3 or less, or less than 2.2, or 2.1 or less, or 1.5 or more, or 2.0 or more.

In the present invention, the weight average molecular weight (Mw) and number average molecular weight (Mn) of the propylene-1-butene copolymer were measured for the molecular weight distribution using gel permeation chromatography (GPC), and the ratio of the weight average molecular weight to the number average molecular weight as the molecular weight distribution (Mw / Mn) was calculated. Specifically, the measurement can be performed using a Waters PL-GPC220 instrument as a gel permeation chromatography (GPC) device and a Polymer Laboratories PLgel MIX-B 300 mm long column. At this time, the measurement temperature is 160 ℃, 1,2,4-trichlorobenzene was used as a solvent, and the flow rate was 1 mL / min. In addition, each polymer sample was prepared at a concentration of 10 mg/10 mL, and then supplied in an amount of 200 µL. The values of Mw and Mn can be derived using a calibration curve formed using polystyrene standard specimens. At this time, the polystyrene standard specimen has a weight average molecular weight of 2,000 g/mol / 10,000 g/mol / 30,000 g/mol / 70,000 g/mol / 200,000 g/mol / 700,000 g/mol / 2,000,000 g/mol / 4,000,000 g/mol / 10,000,000 g/mol 9 types were used.

In addition, the propylene-1-butene copolymer includes 1-butene in an amount of 0.5 to 5% by weight based on the total weight of the copolymer.

Conventionally, when producing a propylene-ethylene random copolymer using ethylene as a comonomer, a heterogeneous comonomer enters between the main chains and deforms the lamellar structure of the resin, resulting in a decrease in strength. On the other hand, in the present invention, by using 1-butene, which is an alpha-olefin, as a comonomer, it is possible to suppress a decrease in strength and improve transparency at the same time. In addition, the present invention can exhibit a narrow molecular weight distribution even in random polymerization with a high conversion rate by including 1-butene in the above content range using a metallocene-based catalyst having a specific structure described later, and also exhibits improved strength characteristics with excellent transparency. Considering the excellent effect of improving strength and transparency by controlling the 1-butene content, the content of 1-butene in the propylene-1-butene copolymer is 0.7% by weight or more, or 1% by weight or more, and 4.5% by weight or less, or 4% by weight or less.

On the other hand, the content of 1-butene in the propylene-1-butene copolymer in the present invention, according to the American Society for Testing and Materials standard ASTM D 5576, after fixing the film or film-type specimen of the propylene-1-butene copolymer to the magnetic holder of the FT-IR equipment, 4800 ~ 3500 cm -1 reflecting the thickness of the specimen in the IR absorption spectrum Measure the height of the peak and the area of the 790 ~ 660 cm ^-1 peak where the 1-butene component appears, respectively , The 1-butene content can be calculated by substituting the measured value into the calibration equation obtained by plotting the area of the 790-660 ^{cm -1 peak} of the standard sample divided by the peak height of 4800-3500 cm ^-1 .

As such, the propylene-1-butene copolymer according to one embodiment of the present invention has a high melt index and melting point, a low xylene soluble content and a narrow molecular weight distribution, so that when applied to a resin composition, it exhibits high stiffness and flexural modulus along with high transparency.

The propylene-1-butene copolymer according to one embodiment of the present invention having the above physical properties and structural characteristics can be prepared by a manufacturing method comprising the steps of introducing hydrogen gas at 300 to 2500 ppm based on the total weight of the monomers for forming the propylene-1-butene copolymer and randomly copolymerizing the propylene monomer and the 1-butene monomer in the presence of a catalyst composition containing a transition metal compound represented by Formula 1 as a catalytically active component. Accordingly, according to another embodiment of the present invention, a method for preparing a propylene-1-butene copolymer as described above is provided:

[Formula 1]

In Formula 1,

X ₁ and X ₂ are the same as or different from each other, and each independently represents a halogen;

R ₁ and R ₅ are the same as or different from each other, and 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 the same as or different _from each other, and 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;

R ₉ and R ₁₀ are the same as each other and are C _2-20 alkyl.

On the other hand, in the present specification, the following terms may be defined as follows unless there is a particular limitation.

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 C1-20 alkyl group may be 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, neo-pentyl group, or cyclohexyl group.

The C _2-20 alkenyl group may be a straight-chain, branched-chain or cyclic alkenyl group. Specifically, the C _2-20 alkenyl group is a C _2-20 straight-chain alkenyl group, a C _2-10 straight-chain alkenyl group, a C _2-5 straight-chain alkenyl group, a C 3-20 branched-chain alkenyl group, a C _3-15 branched-chain alkenyl group, a C _3-10 branched-chain alkenyl _{group, a C 5-20 cyclic alkenyl group, or a C 5-10 cyclic alkenyl} group. can be 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 _6-30 aryl can mean a monocyclic, bicyclic or tricyclic aromatic hydrocarbon. Specifically, C _6-30 aryl may be a phenyl group, a naphthyl group, or an anthracenyl group.

C _7-30 alkylaryl may mean a substituent in which one or more hydrogens of aryl are substituted with alkyl. Specifically, the C _7-30 alkylaryl may be methylphenyl, ethylphenyl, n-propylphenyl, iso-propylphenyl, n-butylphenyl, iso-butylphenyl, tert-butylphenyl or cyclohexylphenyl.

C _7-30 arylalkyl may mean a substituent in which one or more hydrogens of alkyl are substituted by aryl. Specifically, C _7-30 arylalkyl may be a benzyl group, phenylpropyl, or phenylhexyl.

In the method for preparing the propylene-1-butene copolymer according to an embodiment of the present invention, the catalyst composition includes the compound of Formula 1 as a single catalyst. Accordingly, the molecular weight distribution of the prepared propylene-1-butene copolymer may be remarkably narrowed compared to the case where two or more types of catalysts are mixed and used in the related art.

Furthermore, the compound of Formula 1, as a bridge group connecting two ligands including an indenyl group, includes a divalent functional group A 2 substituted with the same alkyl group having 2 or more carbon atoms, thereby increasing the atomic size compared to the existing carbon bridge. As the solubility angle increases, the approach of the monomers becomes easier and thus more excellent catalytic activity can be exhibited.

In addition, the 2-position of both indenyl groups, which are ligands, is substituted with a methyl group, and the 4-position (R ₁ and R ₅ ) contain an alkyl-substituted phenyl group, respectively, so that sufficient electrons can be supplied. By an inductive effect, more excellent catalytic activity can be exhibited.

In addition, by including zirconium (Zr) as a central metal, the compound of Formula 1 has more orbitals capable of accepting electrons compared to the case of containing other Group 14 elements such as Hf, etc., and thus has higher affinity.

More specifically, R ₁ and R ₅ in Formula 1 may each independently be a C _6-12 aryl group substituted with C _1-10 alkyl, and more specifically, 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 R ₁ or R ₅ bonded to the indenyl group and the para position.

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 represent chloro.

In Formula 1, A may be silicon, and substituents R ₉ and R ₁₀ of A may be identical to each other in terms of increasing solubility and improving loading efficiency, and may be a C _2-10 alkyl group, more specifically, a C _2-4 straight-chain alkyl group, and more specifically, each may be ethyl. When a methyl group is included as a substituent of such a bridge, poor solubility may occur when preparing a supported catalyst, resulting in poor supported reactivity.

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

(1a)

The compound of Formula 1 may be synthesized by applying known reactions, and reference may be made to Preparation Examples to be described later for a more detailed synthesis method.

Meanwhile, the compound of Chemical Formula 1 may be used as a single component or may be used as a supported catalyst supported on a carrier.

When used in a supported catalyst state, the particle shape and bulk density of the prepared polymer are excellent, and can be suitably used in conventional slurry polymerization, bulk polymerization, or gas phase polymerization processes.

As the carrier, a carrier having a hydroxyl group or a siloxane group on its surface may be used. Preferably, a carrier containing a highly reactive hydroxyl group and a siloxane group may be used, in which water is removed from the surface by drying at a high temperature. Specific examples of the support include silica, alumina, magnesia, silica-alumina, silica-magnesia, and the like, which typically include oxides, carbonates, sulfates, and nitrates such as Na ₂ O, K ₂ CO ₃ , BaSO ₄ , and Mg(NO ₃ ) ₂ . Among them, in the case of silica, since the silica carrier and the functional group of the metallocene 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, when polypropylene is produced by slurry or gas phase polymerization, fouling in which the polymer particles stick to each other or the wall surface of the reactor can be minimized.

When the compound of Formula 1 is supported on a carrier, the weight ratio of the compound of Formula 1 to the carrier may be 1:1 to 1:1000. When the carrier and the compound of Formula 1 are included in the above weight ratio, appropriate supported catalytic activity may be exhibited, which may be advantageous in terms of maintaining the activity of the catalyst and economic efficiency. More specifically, the weight ratio of the compound of Formula 1 to the carrier may be 1:10 to 1:30, more specifically 1:15 to 1:20.

In addition, the catalyst composition may further include a cocatalyst in terms of improving high activity and process stability.

The cocatalyst may include at least one selected from a compound represented by Formula 2, a compound represented by Formula 3, and a compound represented by Formula 4:

[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 hydrocarbon; or C _1-20 hydrocarbon substituted with halogen;

m is an integer of 2 or greater;

[Formula 3]

J(R ₁₂ ) ₃

In Formula 3,

R ₁₂ 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 4]

[EH] ⁺ [ZD ₄ ] ^- or [E] ⁺ [ZD ₄ ] ^-

In Formula 4,

E is a neutral or cationic Lewis base;

H is a hydrogen atom;

Z is a Group 13 element;

D may be the same as or different from each other, and each independently represents a C _6-20 aryl group or C _1-20 alkyl group in which one or more hydrogen atoms are unsubstituted or substituted with halogen, C _1-20 hydrocarbon, alkoxy or phenoxy.

Examples of the compound represented by Formula 2 include alkylaluminoxane-based compounds such as methylaluminoxane, ethylaluminoxane, isobutylaluminoxane, or butylaluminoxane, and any one or a mixture of two or more thereof may be used.

Examples of the compound represented by Formula 3 include trimethyl aluminum, triethyl aluminum, triisobutyl aluminum, tripropyl aluminum, tributyl aluminum, dimethylchloro aluminum, triisopropyl aluminum, tri-s-butyl aluminum, tricyclopentyl aluminum, tripentyl aluminum, triisopentyl aluminum, trihexyl aluminum, trioctyl aluminum, ethyl di methyl aluminum, methyl diethyl aluminum, triphenyl aluminum, tri-p-tolyl aluminum, dimethyl aluminum methoxide, dimethyl aluminum ethoxide, trimethyl boron, triethyl boron, triisobutyl boron, tripropyl boron, tributyl boron, and the like, and any one or a mixture of two or more of these may be used. More specifically, one or more compounds selected from trimethylaluminum, triethylaluminum, and triisobutylaluminum may be used.

Examples of the compound represented by Formula 4 include triethylammonium tetraphenylboron, tributylammonium tetraphenylboron, trimethylammonium tetraphenylboron, tripropylammonium tetraphenylboron, trimethylammonium tetra(p-tolyl) boron, trimethylammonium tetra(o,p-dimethylphenyl)boron, tributylammonium tetra(p-trifluoromethylphenyl)boron, and trimethylammonium. Nium tetra(p-trifluoromethylphenyl)boron, tributylammonium tetrapentafluorophenylboron, N,N-diethylaniliniumtetraphenylboron, N,N-diethylanilinium tetrapentafluorophenylboron, diethylammonium tetrapentafluorophenylboron, triphenylphosphonium tetraphenylboron, trimethylphosphonium tetraphenylboron, triethylammonium tetraphenylaluminum, tributylam Monium 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, trimethyl Ammonium tetra(p-trifluoromethylphenyl) aluminum, tributylammonium tetrapentafluorophenyl aluminum, N,N-diethylanilinium tetraphenyl aluminum, N,N-diethylanilinium tetrapentafluorophenyl aluminum, diethylammonium tetrapentate tetraphenyl aluminum, triphenylphosphonium tetraphenyl aluminum, trimethylphosphonium tetraphenyl aluminum, trimethylphosphonium tetraphenyl aluminum propylammonium tetra(p-tolyl) boron, triethylammonium tetra(o,p-dimethylphenyl)boron, tributylammonium tetra(p-trifluoromethylphenyl)boron, triphenylcarboniumtetra(p-trifluoromethylphenyl)boron, and triphenylcarbonium tetrapentafluorophenylboron, and any one or a mixture of two or more of these may be used.

More specifically, the cocatalyst may be an alkylaluminoxane-based cocatalyst.

The alkylaluminoxane-based cocatalyst stabilizes the transition metal compound of Formula 1 and acts as a Lewis acid to further enhance catalytic activity by including a metal element capable of forming a bond with a functional group introduced into a bridge group of the transition metal compound of Formula 1 through Lewis acid-base interaction.

When the cocatalyst is further included, the weight ratio of the compound of Formula 1 to the cocatalyst may be 1:1 to 1:20. When the cocatalyst and the compound of Formula 1 are included in the above weight ratio, appropriate supported catalyst activity may be exhibited, which may be advantageous in terms of maintaining the activity of the catalyst and economic efficiency. More specifically, the weight ratio of the compound of Formula 1 to the cocatalyst may be 1:5 to 1:20, more specifically 1:5 to 1:15.

The catalyst composition having the above structure may be prepared by a manufacturing method including the step of supporting a cocatalyst compound on a carrier, and the step of supporting the compound represented by Formula 1 on the carrier. However, considering the effect of the supported catalyst having a structure determined according to the supporting order on the catalytic activity and process stability in the polypropylene manufacturing process, supporting the compound of Formula 1 after supporting the cocatalyst has higher catalytic activity and excellent process stability. Can be implemented.

Meanwhile, in the method for preparing the propylene-butene copolymer according to an embodiment of the present invention, the polymerization reaction may be performed by contacting a catalyst composition including the transition metal compound of Formula 1 with a propylene monomer and a 1-butene monomer.

In this case, the propylene and 1-butene may be used in a weight ratio of 99.9:0.1 to 90:10, or 99.5:0.5 to 93:7, or 99.1:0.9 to 96:4, or 99.1:0.9 to 94:6. In the polymerization process, the weight ratio of 1-butene should be 99.9:0.1 or more in terms of realizing sufficient physical properties, and should be 90:10 or less in terms of the limit of production in the bulk polymerization process.

In addition, the polymerization of the propylene-1-butene copolymer may be carried out in 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. Various polymerization processes known as polymerization reactions of olefin monomers may be employed. In particular, in terms of obtaining a uniform molecular weight distribution and commercial production of products, a continuous bulk-slurry polymerization process may be employed.

In addition, the polymerization reaction may be carried out at a temperature of 40 ° C or higher, 60 ° C or higher, or 70 ° C or higher, 110 ° C or lower or 100 ° C or lower, and when the pressure condition is further controlled, 1 kgf / cm ² or higher, or 30 kgf / cm ² or higher, and 100 kgf / cm ² Or less, or 50 kgf / cm ² It may be carried out under a pressure of less than.

In addition, the polymerization reaction is carried out under the condition of introducing hydrogen gas.

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

The hydrogen gas may be introduced in an amount of 300 ppm or more, 330 ppm or more, 2500 ppm or less, 1000 ppm or less, or 500 ppm or less, based on the total weight of the monomers for forming the propylene-1-butene copolymer. By adjusting the amount of hydrogen gas used within the above range, the molecular weight distribution and fluidity of the prepared propylene-1butene copolymer can be adjusted within a desired range while exhibiting sufficient catalytic activity, and thus a copolymer having appropriate physical properties depending on the use can be prepared. More specifically, the compound of Chemical Formula 1 has very good hydrogen reactivity, so that the chain transfer reaction is activated as the amount of hydrogen gas used is increased, and thus polypropylene having a reduced molecular weight and a high melt index can be obtained. When the amount of hydrogen gas used is less than 300 ppm, the melt index is significantly lowered and processability may be deteriorated. When the amount exceeds 2500 ppm, the MI is excessively increased and the physical properties of the injection molded product may be deteriorated.

In addition, during the polymerization reaction, trialkylaluminum such as triethylaluminum may be selectively added in an amount of 10 ppm or more, or 30 ppm or more, and 70 ppm or less, or 50 ppm or less, based on the total weight of the monomers for preparing the propylene-1-butene copolymer. Realization of the physical properties of the propylene-1-butene copolymer may be easier during polymerization in the presence of such an amount of trialkylaluminum.

In addition, in the polymerization reaction, the catalyst composition may be used in a dissolved or diluted state in an aliphatic hydrocarbon solvent having 5 to 12 carbon atoms suitable for the polymerization process of propylene monomer, for example, pentane, hexane, heptane, nonane, decane, and isomers thereof, aromatic hydrocarbon solvents such as toluene and benzene, and hydrocarbon solvents substituted with chlorine atoms such as dichloromethane and chlorobenzene. At this time, by treating the solvent with a small amount of alkylaluminum, a small amount of water or air that may act as a catalyst poison can be removed.

As described above, the method for producing a propylene-1-butene copolymer according to an embodiment of the present invention optimizes the weight ratio of 1-butene, a comonomer, and at the same time uses the transition metal compound of Formula 1 as a catalytically active component, so that the prepared copolymer has a high MI, low xylene soluble content and a narrow molecular weight distribution. It can be particularly useful for the manufacture of injection molded articles of this type.

Accordingly, according to another embodiment of the present invention, a resin composition containing the propylene-1-butene copolymer, a method for preparing the same, and an injection-molded product manufactured using the same are provided.

Specifically, the resin composition includes the above-described propylene-1-butene copolymer, a nucleating agent, and optionally other additives, and adds a nucleating agent to the propylene-1-butene copolymer prepared according to the above-described manufacturing method. It can be prepared by a manufacturing method comprising the step of extruding.

More specifically, in the presence of a catalyst composition containing the transition metal compound of Formula 1, hydrogen gas is introduced at 300 to 2500 ppm, and propylene monomer and 1-butene monomer are randomly copolymerized to prepare a propylene-1-butene copolymer; and adding a nucleating agent to the propylene-1-butene copolymer and extruding it. At this time, the preparation step of the propylene-1butene copolymer is the same as described above.

In the step of being extruded together with the propylene-1-butene copolymer, the nucleating agent makes the crystal size of the resin small to inhibit light dispersion, thereby further improving the transparency and fluidity of the resin composition. As the nucleating agent, a carbon-based compound may be used, and specifically, a sorbitol-based nucleating agent such as benzylidenesorbitol, methylbenzylidenesorbitol, ethylbenzylidenesorbitol, and 3,4-dimethylbenzylidenesorbitol, and a nonitol-based nucleating agent such as 1,2,3-trideoxy-4,6:5,7-bis-O-[(4-propylphenyl)methylene]-nonitol, and the like may be used. In addition, commercially available nucleating agents such as Millad 3988™ (manufactured by Milliken), NX8000™ (manufactured by Milliken), or NU700™ (manufactured by Dongbu Chemical) may be used.

In order to sufficiently improve transparency and flowability according to the use of the nucleating agent, the nucleating agent may be used in an amount of 1500 ppm or more, or 1800 ppm or more, 3000 ppm or less, or 2200 ppm or less based on the total weight of the propylene-1-butene copolymer.

In addition to the above-described nucleating agent, one or more additives such as a neutralizer, an antioxidant, a slip agent, an anti-blocking agent, a UV stabilizer, and an antistatic agent may be further added to improve physical properties of the resin composition.

Calcium stearate and the like may be used as the neutralizing agent.

Further, examples of the antioxidant include phenolic antioxidants such as tetrakis(methylene(3,5-di-t-butyl-4-hydroxy)hydrosilylnate) or 1,3,5-trimethyl-tris(3,5-di-t-butyl-4-hydroxybenzene); or a phosphorus-based antioxidant, and the like, any one or a mixture of two or more of these may be used. Commercially available antioxidants include Irganox 1010™ (manufactured by BASF), Irganox 168™ (manufactured by BASF), and the like. Phenol-based antioxidants have superior properties in preventing decomposition by heat compared to conventional antioxidants such as phosphorus antioxidants, and phosphorus-based antioxidants have better compatibility with polymers in resin compositions. More specifically, phenolic antioxidants and phosphorus-based antioxidants can be mixed and used in a weight ratio of 2: 1 to 1:2, or 1: 1.5 to 1: 2.

As the slip agent, Erucamide (manufactured by ALDRICH) may be used as a commercially available material.

In addition, as the anti-blocking agent, SiO ₂ and the like may be used.

The content of the additives may be determined within a range that does not impair the physical properties of the resin composition, and specifically, 500 ppm or more, or 700 ppm or more, 2500 ppm or less, or 1500 ppm or less, respectively, based on the total weight of the propylene-1-butene copolymer.

The extrusion process may be performed according to a conventional method, and specifically, may be performed at 150 to 250 ° C. and 100 to 1000 rpm using an extruder such as Haake Rheocord or Leistritz. In addition, when the resin composition is to be obtained in the form of pellets, using a pelletizer, a strand is pulled at 5 to 15 kg / h at 180 to 220 ° C., and the strand is pelletized with a pelletizer at about 500 to 900 rpm.

The resin composition exhibits excellent transparency and high stiffness and flexural modulus by including the propylene-1-butene copolymer, and in particular, as the copolymer has a high melt index, it can be useful as a resin composition for injection molding for the manufacture of injection molded articles requiring high transparency and rigidity, and furthermore, thin film type injection molded articles such as films and sheets.

Specifically, the resin composition has a haze value measured at 1 mm intervals according to ASTM D1003 of 20% or less or 19% or less, and a flexural modulus value measured according to ASTM D790 of 13,000 kgf/cm 2 or more and 17000 kgf/cm 2 or less.

Hereinafter, preferred embodiments are presented to aid 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.

<Preparation of catalyst>

Preparation Example 1: Preparation of transition metal compound and supported catalyst

Step 1) ( diethylsilane - the day )- bis ((2- methyl -4-(4- tut -butyl-phenyl) indenyl ) silane manufacturing

After dissolving 2-methyl-4-tert-butyl-phenylindene (20.0 g) in a toluene/THF mixed solution (volume ratio of toluene/THF = 10/1, 220 mL), an n-butyllithium solution (2.5 M, hexane solvent, 22.2 g) was slowly added dropwise at 0°C, followed by stirring at room temperature for one day. Thereafter, diethyldichlorosilane (6.2 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. Thereafter, water was added to separate the organic layer, and the solvent was distilled under reduced pressure to obtain (diethylsilane-diyl)-bis((2-methyl-4-(4-tert-butyl-phenyl)indenyl)silane.

Step 2) [( diethylsilane - the day )- Bis((2-methyl-4-(4-tert-butyl-phenyl)indenyl )] Preparation of zirconium dichloride

After dissolving (diethylsilane-diyl)-bis((2-methyl-4-(4-tert-butyl-phenyl)indenyl)silane prepared in step 1 in a toluene/THF mixed solution (volume ratio of toluene/THF = 5/1, 120 mL), n-butyllithium solution (2.5M, hexane solvent, 22.2g) was slowly added dropwise at -78°C, followed by stirring at room temperature for one day. After diluting zirconium chloride (8.9 g) in toluene (20 mL), it was slowly added dropwise at -78 ° C and stirred for one day at room temperature. The solvent in the reaction solution was removed under reduced pressure, dichloromethane was added and filtered, and the filtrate was distilled off under reduced pressure. butyl-phenyl)indenyl)]zirconium dichloride (10.1 g, 34%, rac:meso=20:1) was obtained.

(1a)

Step 3) Preparation of Supported Catalyst

100 g of silica and 670 g of a 10 wt % methylaluminoxane solution (solvent: toluene) were placed in a 3 L reactor and reacted at 90° C. for 24 hours. After precipitation, the upper layer was removed and washed twice with toluene. The antha-metallocene compound rac-[(diethylsilane-diyl)-bis((2-methyl-4-(4-tert-butyl-phenyl)indenyl)]zirconium dichloride (5.8 g) prepared in step 2 was diluted in toluene and added to the reactor, followed by reaction at 70 ° C. for 5 hours. Washed again and vacuum dried to obtain 150 g of a silica-supported metallocene catalyst in the form of solid particles.

Comparative Preparation Example 1

Instead of the transition metal compound prepared in step 2 of Preparation Example 1, a [(dimethylsilanediyl)-bis(2-methyl-4-phenylindenyl)]zirconium dichloride transition metal compound (I) having the following structure was used, and a silica-supported metallocene catalyst was prepared in the same manner as in Step 3 of Preparation Example 1.

(I)

Comparative Preparation Example 2

Instead of the transition metal compound prepared in step 2 of Preparation Example 1, [(6-t-butoxyhexylmethylsilanediyl) -bis (2-methyl-4-phenylindenyl)] zirconium dichloride of the following structure Except for using a transition metal compound (II), a silica-supported metallocene catalyst was prepared in the same manner as in Step 3 of Preparation Example 1.

(II)

<Polymer preparation>

Example 1-1

As shown in Table 1 below, a propylene-butene copolymer (C4-random copolymer) was obtained by adjusting the content of propylene, the content of 1-butene, and polymerization process conditions.

Specifically, a 2L stainless reactor was vacuum-dried at about 65° C., then cooled, and triethyl aluminum (TEAL), hydrogen, 1-butene, and propylene were sequentially introduced at room temperature. After stirring for about 10 minutes, 0.048 g of the silica-supported metallocene catalyst prepared in Preparation Example 1 was dissolved in about 20 mL of trimethylaluminum (TMA)-prescribed hexane and introduced into the reactor at the input amount shown in Table 1 under nitrogen pressure. Thereafter, the temperature of the reactor was slowly raised to about 70 °C, followed by polymerization for about 1 hour. After completion of the reaction, unreacted propylene and 1-butene were removed by venting and drying.

Examples 1-2 to 1-4

A propylene-butene copolymer (C4-random copolymer) was obtained in the same manner as in Example 1-1, except for the conditions described in Table 1 below.

Comparative Examples 1-1 to 1-3

A propylene-butene copolymer (C4-random copolymer) was prepared in the same manner as in Example 1-1, except that the silica-supported metallocene catalyst prepared in Comparative Preparation Example 1 was used instead of the supported metallocene catalyst in Example 1-1, and carried out under the conditions described in Table 1 below.

Comparative Examples 1-4 and 1-5

A propylene-ethylene copolymer (C2-random copolymer) was prepared in the same manner as in Example 1-1, except that the supported catalyst prepared in Comparative Preparation Example 2 was used, ethylene was used instead of 1-butene, and carried out under the conditions described in Table 1 below.

A 2L stainless reactor was vacuum-dried at 65 °C, cooled, and triethylaluminum, hydrogen, and propylene were sequentially introduced at room temperature. After stirring for 10 minutes, 0.048 g of the silica-supported metallocene catalyst prepared in Comparative Preparation Example 2 was dissolved in 20 mL of TMA-prescribed hexane under nitrogen pressure and added to the reactor at the input amount shown in Table 1. Thereafter, the temperature of the reactor was slowly raised to 70° C. while adding ethylene, followed by polymerization for 1 hour. After completion of the reaction, unreacted propylene and ethylene were vented.

Comparative Example 1-6

A propylene-1-butene copolymer (C4-random copolymer) was prepared in the same manner as in Example 1-1, except that the supported catalyst prepared in Comparative Preparation Example 2 was used and carried out under the conditions shown in Table 1 below.

In the process of preparing the resin compositions according to Examples 1-1 to 1-4 and Comparative Examples 1-1 to 1-6, specific propylene content, 1-butene content, polymerization conditions, etc. are shown in Table 1 below.

Example comparative example 1-1 1-2 1-3 1-4 1-1 1-2 1-3 1-4 1-5 1-6 polymer type C4-random copolymer C4-random copolymer C4-random copolymer C4-random copolymer C4-random copolymer C4-random copolymer C4-random copolymer C2-random copolymer C2-random copolymer C4-random copolymer catalyst Preparation Example 1 Preparation Example 1 Preparation Example 1 Preparation Example 1 Comparative Preparation Example 1 Comparative Preparation Example 1 Comparative Preparation Example 1 Comparative Preparation Example 2 Comparative Preparation Example 2 Comparative Preparation Example 2 catalytic amount
(g/hr) 1.0 1.1 1.2 1.2 1.1 1.1 1.1 1.0 1.1 1.2 Pressure (kg/cm ² ) 35 35 35 35 35 35 35 35 35 35 Propylene input (kg/hr) 40 40 40 40 40 40 40 40 40 80 Butene [C4] input (% by weight) 0.4 1.0 1.4 1.8 One 1.5 2 - - 2.3 Ethylene [C2] input (wt%) - - - - - - - 6.3 6.6 - TEAL dosage (ppm) 50 50 50 50 50 50 50 50 50 50 Polymerization temperature (℃) 70 70 70 70 70 70 70 70 70 70 Hydrogen input (ppm) 330 330 330 330 500 500 500 300 300 100 Catalytic activity (kg/g cat) 32 31 32 30 2 2 One 28 28 30

In Table 1, the weight percent of butene [C4] or ethylene [C2] input is based on the total weight of the monomers used for preparing the polymer. In addition, in Table 1, the catalyst activity was calculated as the ratio of the weight (kg PP) of the polymer produced per mass (g) of the supported catalyst used on the basis of unit time (h) and the weight (kg PP) of the polymer produced per metallocene compound content (μmol) contained in the supported catalyst.

Test Example 1: Evaluation of physical properties of copolymer

The physical properties of the copolymers prepared according to Examples 1-1 to 1-4 and Comparative Examples 1-1 to 1-6 were evaluated in the following manner. The results are shown in Table 2 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) Xylene Soluble (wt%): Xylene was added to each copolymer sample, heated at 135 ° C. for 1 hour, and cooled for 30 minutes to pre-treat. When the base lines of RI, DP, and IP were stabilized by flowing xylene for 4 hours at a flow rate of 1 mL/min in OminiSec (Viscotek FIPA) equipment, the concentration of the pretreated sample and the amount of injection were recorded and measured, and the peak area was calculated.

(3) Melting point (Tm): After the temperature of the copolymer was increased to 200 ° C., maintained at that temperature for 5 minutes, then lowered to 30 ° C., and then increased again, the top of the DSC (Differential Scanning Calorimeter, manufactured by TA) curve 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.

(4) Molecular weight distribution (MWD, polydispersity index): The weight average molecular weight (Mw) and number average molecular weight (Mn) of the polymer were measured using gel permeation chromatography (GPC), and the measured weight average molecular weight was divided by the number average molecular weight. The molecular weight distribution (MDW, that is, Mw / Mn) was calculated.

Specifically, a Waters PL-GPC220 instrument was used as a gel permeation chromatography (GPC) apparatus, and a Polymer Laboratories PLgel MIX-B 300 mm long column was used. At this time, the measurement temperature was 160 °C, 1,2,4-trichlorobenzene was used as a solvent, and the flow rate was 1 mL/min. Samples of the copolymer were each prepared at a concentration of 10 mg/10 mL, and then supplied in an amount of 200 μL. The values of Mw and Mn were derived using a calibration curve formed using polystyrene standard specimens. The weight average molecular weight of polystyrene standard specimens is 9 species was used.

(5) 1-butene (C4) and ethylene (C2) content (% by weight)

According to ASTM D 5576 of the American Society for Testing and Materials, after fixing the film or film-type specimen of the copolymer according to the above examples or comparative examples to the magnetic holder of the FT-IR equipment, the height of the 4800 ~ 3500 cm ^-1 peak reflecting the thickness of the specimen in the IR absorption spectrum and the area of the 790 ~ 660 cm ^-1 peak in which the 1-butene component appears are measured, and the measured value is the area of the 790 ~ 660 cm ^-1 peak of the standard sample 4800 ~ 3500 cm ^-1 The value divided by the peak height was substituted into the calibration formula obtained by plotting to calculate the 1-butene content.

In addition, in the case of ethylene, the area of the 710 to 760 cm ^-1 peak where the ethylene component appears was measured and calculated.

Example comparative example 1-1 1-2 1-3 1-4 1-1 1-2 1-3 1-4 1-5 1-6 MI (g/10min) 56.3 56.8 55.4 60 21.5 20.8 21.0 45 70 12.5 Xylene soluble content (% by weight) 0.5 0.5 0.6 0.6 0.6 0.7 0.6 0.6 0.8 0.7 Tm (℃) 150.6 147.5 144.2 142.0 145.8 143.3 141.8 136.5 136.9 141.5 MWD 2.1 2.1 2.1 2.1 2.2 2.2 2.2 3.4 3.8 3.5 C2 content
(weight%) 0 0 0 0 0 0 0 2.9 3.1 0 C4 content (% by weight) 1.0 2.0 3.0 4.0 2.0 3.0 4.0 0 0 2.3

As a result of the experiment, the propylene-1-butene copolymers of Examples 1-1 to 1-4 prepared by the production method according to the present invention exhibited a high MI, a narrow MWD, and a low xylene soluble content and residual stress ratio. In addition, the propylene-1-butene copolymers of Examples 1-1 to 1-4 had an equivalent level of melting point compared to the copolymers of Comparative Examples 1-1 to 1-3 prepared using a metallocene compound having a different structure as a catalytically active material, and exhibited a remarkably high melt index. From this, it can be seen that the propylene-1-butene copolymers of Examples 1-1 to 1-4 are more useful for injection molding.

In addition, in the case of the propylene-ethylene copolymers of Comparative Examples 1-4 and 1-5, relatively high MI and low xylene soluble content were exhibited, but compared to the copolymer of Example 1-3 containing 1-butene at the same level as the ethylene content in the propylene-ethylene copolymer, it can be seen that the rigidity is greatly reduced by showing a remarkably widened MWD.

In addition, in the preparation of the propylene-1-butene copolymer, the copolymer of Comparative Example 1-6 in which the same catalyst as in the preparation of the copolymers of Comparative Examples 1-4 and 1-5 was used and the amount of hydrogen input was significantly reduced showed a significantly reduced melt index and a wide MWD compared to the propylene-1-butene copolymers of Examples 1-1 to 1-4. From this, it can be seen that the injection moldability and rigidity are lowered.

<Preparation of resin composition>

Example 2-1

In 100 kg of the copolymer prepared in Example 1-1, Millad 3988?? (manufactured by Milliken) 2000 ppm, neutralizing agent (Calcium stearate) 500 ppm, primary antioxidant (Irganox™ 1010, manufactured by BASF) 500 ppm, secondary antioxidant (Irganox 168™, manufactured by BASF) 1000 ppm, slip agent (Erucamide, manufactured by ALDRICH) 1000 ppm, and anti-blocking agent (SiO ₂ , manufactured by SIPERNAT) after prescribing 1000 ppm of additives, extruding using a Haake Rheocord extruder under conditions of 200 rpm at 220 ° C., and then pulling out strands at 10 kg / h at 200 ° C., and preparing this strand with a pelletizer at approximately 700 rpm to prepare a pelletized resin composition.

Examples 2-2 to 2-4, Comparative Examples 2-1 to 2-6

A resin composition was prepared in the same manner as in Example 2-1, except that the copolymers in Examples 1-2 to 1-4 and Comparative Examples 1-1 to 1-6 were used instead of the copolymer prepared in Example 1-1, and a nucleating agent was used under the conditions shown in Table 3 below.

Test Example 2: Evaluation of resin composition

Transparency (haze) and flexural modulus of the resin compositions prepared in Examples 2-1 to 2-4 and Comparative Examples 2-1 to 2-6 were measured in the following manner, and the results are shown in Table 3.

(1) Haze: The degree (%) of light refraction was measured when light was projected on 1T (1mm) and 2T (2mm) of the specimen according to ASTM D1003. Haze can measure the transparency of a specimen as Td (refracted light)/Tt (passed light) x 100 (%).

(2) Flexural modulus: After fixing the specimen on a support according to ASTM D790, the strength (Kgf/cm2) taken when a load was applied at approximately 30 to 50 mm/min with a loading nose was measured. Flexural modulus, which represents stiffness, was measured as the initial slope value according to the flexural strength and flexural force, which is the maximum value at which the loading nose no longer increases.

Example comparative example 2-1 2-2 2-3 2-4 2-1 2-2 2-3 2-4 2-5 2-6 polymer type C4-random copolymer C4-random copolymer C4-random copolymer C4-random copolymer C4-random copolymer C4-random copolymer C4-random copolymer C2-random copolymer C2-random copolymer C4-random copolymer nucleating agent
(ppm) 2000 2000 2000 2000 2000 2000 2000 2000 2000 2000 haze
(%) (1 mm) 18.5 15.5 12.7 10.6 15.8 13.6 11.2 7.3 9.5 14.8 flexural modulus
(kg/cm ² ) 15832 15092 14226 13881 12556 12105 11915 12850 12762 12200

Experimental Results The resin compositions of Examples 2-1 to 2-4 prepared by adding a nucleating agent to the propylene-1-butene copolymer according to the present invention and extruding the resin compositions of Examples 2-1 to 2-4 exhibited excellent transparency at the same level as those of Comparative Examples 2-1 to 2-6, while exhibiting a remarkably high flexural modulus of 13000 kg/cm ² or more.

Claims (13)

A propylene-1-butene copolymer, which satisfies the following conditions and is a random copolymer:
i) Melt index (measured with 2.16 kg load at 230°C according to ASTM D1238): 50 to 65 g/10min
ii) Xylene soluble content: 0.1 to 1.0% by weight
iii) melting point: 130 to 155 ° C.
iv) molecular weight distribution: 1.5 to 2.4
v) 1-butene content: 0.5 to 5% by weight relative to the total weight of the copolymer.
delete delete According to claim 1,
The propylene-1-butene copolymer, wherein the xylene soluble content of the propylene-1-butene copolymer is 0.1 to 0.7% by weight.
According to claim 1,
The propylene-1-butene copolymer having a molecular weight distribution of 1.5 to 2.3.
A process for producing a propylene-1-butene copolymer according to claim 1, comprising the step of randomly copolymerizing a propylene monomer and a 1-butene monomer in the presence of a catalyst composition containing a transition metal compound of Formula 1 below, injecting hydrogen gas at 300 to 2500 ppm:
[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;
R ₉ and R ₁₀ are the same as each other and are C _2-20 alkyl.
According to claim 6,
Wherein R ₁ and R ₅ are each independently a phenyl group substituted with a C _3-6 branched chain alkyl group, a method for producing a propylene-1-butene copolymer.
According to claim 6,
A is silicon,
Wherein R ₉ and R ₁₀ are the same and are C _2-4 straight chain alkyl groups, a method for producing a propylene-1-butene copolymer.
According to claim 6,
The compound of Formula 1 is a compound represented by the following Formula 1a, a method for producing a propylene-1-butene copolymer.
[Formula 1a]

According to claim 6,
The catalyst composition further comprises a silica carrier, a method for producing a propylene-1-butene copolymer.
According to claim 6,
The method for producing a propylene-1-butene copolymer, wherein the catalyst composition further comprises at least one of a compound represented by Formula 2, a compound represented by Formula 3, and a compound represented by Formula 4:
[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 hydrocarbon; or C _1-20 hydrocarbon substituted with halogen;
m is an integer of 2 or greater;
[Formula 3]
J(R ₁₂ ) ₃
In Formula 3,
R ₁₂ 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 4]
[EH] ⁺ [ZD ₄ ] ^- or [E] ⁺ [ZD ₄ ] ^-
In Formula 4,
E is a neutral or cationic Lewis base;
H is a hydrogen atom;
Z is a Group 13 element;
D may be the same as or different from each other, and each independently represents a C _6-20 aryl group or C _1-20 alkyl group in which one or more hydrogen atoms are unsubstituted or substituted with halogen, C _1-20 hydrocarbon, alkoxy or phenoxy.
The propylene-1-butene copolymer according to any one of claims 1, 4 and 5; and a nucleating agent.
In the presence of a catalyst composition comprising a transition metal compound of Formula 1, hydrogen gas is introduced at 300 to 2500 ppm, and propylene monomer and 1-butene monomer are randomly copolymerized to prepare a propylene-1-butene copolymer according to claim 1; and
Method for producing a resin composition comprising the step of extruding by adding a nucleating agent to the propylene-1-butene copolymer:
[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;
R ₉ and R ₁₀ are the same as each other and are C _2-20 alkyl.