KR20210064707A - Transparent polypropylene resin composition with improved mechanical properties - Google Patents

Abstract

The present invention relates to a polypropylene resin composition which can satisfy both rigidity and transparency required for manufacturing film packaging materials or food storage containers through the sheet molding or vacuum/pressure molding using polypropylene. The present invention provides a polypropylene resin composition including: polypropylene prepared by using a catalyst composition containing a transition metal compound represented by chemical formula 1; and a nucleating agent, wherein the polypropylene is a propylene homopolymer or propylene-ethylene random copolymer, and the nucleating agent is a sorbitol-based nucleating agent or a nonitol-based nucleating agent.

Description

High transparent polypropylene resin composition with improved rigidity {Transparent polypropylene resin composition with improved mechanical properties}

The present invention relates to a polypropylene resin composition, and more particularly, to a highly transparent polypropylene resin composition.

Propylene-ethylene random copolymer has excellent transparency and is widely used in products requiring transparency, such as food containers, films, and sheets. However, in the case of multi-use or disposable food packaging containers, lunch boxes, transparent cups, etc., the thickness of the molded article is thin during sheet molding or vacuum/pressure molding, so that it is somewhat limited in application as a propylene-ethylene random copolymer. In particular, the lack of rigidity, which is a mechanical property, lacks the rigidity of the product that consumers feel, the so-called grip feeling.

In general, amorphous polyethylene terephthalate or stretched polystyrene products are applied as transparent food containers or packaging materials, but issues such as heat resistance and deformation at high temperatures, and issues such as harmfulness, are continuously occurring. In addition, as environmental issues have increased recently, the demand for transparent polypropylene that can be recycled and reused is increasing.

However, as described above, the propylene-ethylene random copolymer is somewhat lacking in transparency compared to amorphous polyethylene terephthalate, and in particular, has a disadvantage in that rigidity is significantly lowered. As such, the development of a material that can satisfy both rigidity and transparency required when used as a film packaging material, a food storage container, etc. is required.

On the other hand, attempts have been made to improve transparency and molecular weight characteristics by using polypropylene prepared using a metallocene catalyst in a container, etc., but a technique that satisfies transparency and rigidity at the same time has not been proposed.

Japanese Patent No. 3672500 discloses a resin composition molded into containers and medical instruments by containing a nucleating agent in a polypropylene resin composition prepared with a metallocene catalyst, but the effect on rigidity improvement and high transparency is still insufficient. .

Korean Patent Publication No. 2019-0064338 discloses a polypropylene resin composition having excellent transparency including a polypropylene resin prepared using a metallocene-based catalyst and a transparent nucleating agent in a specific combination. not recognizing

Accordingly, the present invention is to provide a polypropylene resin composition that can satisfy both rigidity and transparency required for manufacturing a film packaging material, a food storage container, etc. through sheet molding or vacuum/pressure molding using polypropylene.

In order to solve the above problems, the present invention provides a polypropylene prepared by using a catalyst composition including a transition metal compound represented by the following formula (1); and a nucleating agent; wherein the polypropylene is a propylene homopolymer or a propylene-ethylene random copolymer, and the nucleating agent is a sorbitol-based nucleating agent or a nonitol-based nucleating agent.

[Formula 1]

In Formula 1, M is a Group 4 transition metal; Q ₁ and Q ₂ are each independently halogen, (C ₁ -C ₂₀ )alkyl, (C ₂ -C ₂₀ )alkenyl, (C ₂ -C ₂₀ )alkynyl, (C ₆ -C ₂₀ )aryl, ( C ₁ -C ₂₀ )alkyl, (C ₆ -C ₂₀ )aryl, (C ₆ -C ₂₀ )aryl(C ₁ -C ₂₀ )alkyl, (C ₁ -C ₂₀ )alkylamido, (C ₆ -C ₂₀ )arylamido or (C ₁ -C ₂₀ )alkylidene; R ₁ , R ₂ , R ₃ and R ₄ are each independently hydrogen; _{(C 1} -C ₂₀ )alkyl with or without acetal, ketal or ether groups; _{(C 2} -C ₂₀ )alkenyl with or without acetal, ketal or ether groups; _{(C 1} -C ₂₀ )alkyl(C ₆ -C ₂₀ )aryl with or without acetal, ketal or ether groups; _{(C 6} -C ₂₀ )aryl(C ₁ -C ₂₀ )alkyl with or without acetal, ketal or ether groups; _{or (C 1} -C ₂₀ )silyl with or without acetal, ketal or ether groups; at least two of R ₁ , R ₂ , R ₃ and R ₄ may be linked to each other to form an aliphatic ring or an aromatic ring; R ₅ , R ₆ , R ₇ and R ₈ are each independently hydrogen; _{(C 1} -C ₂₀ )alkyl with or without acetal, ketal or ether groups; _{(C 2} -C ₂₀ )alkenyl with or without acetal, ketal or ether groups; _{(C 1} -C ₂₀ )alkyl(C ₆ -C ₂₀ )aryl with or without acetal, ketal or ether groups; R ₉ , R ₁₀ , R ₁₁ , R ₁₂ , R ₁₃ , R ₁₄ , R ₁₅ and R ₁₆ are each independently hydrogen; _{(C 1} -C ₂₀ )alkyl with or without acetal, ketal or ether groups; _{(C 2} -C ₂₀ )alkenyl with or without acetal, ketal or ether groups; _{(C 1} -C ₂₀ )alkyl(C ₆ -C ₂₀ )aryl with or without acetal, ketal or ether groups; _{(C 6} -C ₂₀ )aryl(C ₁ -C ₂₀ )alkyl with or without acetal, ketal or ether groups; _{or (C 1} -C ₂₀ )silyl with or without acetal, ketal or ether groups; At least two of R ₉ , R ₁₀ , R ₁₁ , R ₁₂ , R ₁₃ , R ₁₄ , R ₁₅ and R ₁₆ may be linked to each other to form an aliphatic ring or an aromatic ring.

In addition, the propylene-ethylene random copolymer has an ethylene content of 0.1 to 1.5% by weight, and the polypropylene has a melt index (230° C., 2.16 kg load) of 1 to 10 g/10min. provides

In addition, the sorbitol-based nucleating agent includes 1,3:2,4-bis (3,4-dimethylobenzylideno) sorbitol (1,3:2,4-bis (3,4-dimethylobenzylideno) sorbitol), The nonitol-based nucleating agent is 1,2,3-trideoxy-4,6:5,7-bis-O-[(4-propylphenyl)methylene]-nonitol (1,2,3-Trideoxy-4, 6:5,7-bis-O-[(4-propylphenyl)methylene]-nonitol) provides a polypropylene resin composition, characterized in that.

In addition, the nucleating agent provides a polypropylene resin composition, characterized in that contained in 0.1 to 0.5% by weight of the total resin composition.

In addition, the resin composition has a tensile strength (ASTM D638 Type IV standard, 50 mm/min condition) of 350 kgf/cm2 or more, and a flexural modulus (ASTM D790, 10 mm/min condition) of 15,000 kgf/cm2 or more, and cloudy It provides a polypropylene resin composition, characterized in that the degree (Haze) (ASTM D1003, 1 mm thickness basis) is 8% or less.

In addition, the resin composition provides a polypropylene resin composition, characterized in that for use in sheets or vacuum pressure.

According to the present invention, sheet molding or vacuum/pressure molding is performed by applying a sorbitol-based nucleating agent or a nonitol-based nucleating agent as a specific nucleating agent to a propylene homopolymer or propylene-ethylene random copolymer prepared using a metallocene catalyst having a specific structure. It is possible to provide a polypropylene resin composition that can satisfy both rigidity and transparency required in the manufacture of film packaging materials, food storage containers, and the like.

Hereinafter, preferred embodiments of the present invention will be described in detail. In describing the present invention, if it is determined that a detailed description of a related known technology may obscure the gist of the present invention, the detailed description thereof will be omitted. Throughout the specification, when a part "includes" a certain component, it means that other components may be further included, rather than excluding other components, unless otherwise stated.

The present inventors faced the problem of lack of transparency and a significant decrease in rigidity compared to conventional amorphous polyethylene terephthalate when using propylene-ethylene random copolymer in the production of conventional film packaging materials and food storage containers. It was discovered that this problem can be solved when a sorbitol-based nucleating agent is applied as a specific nucleating agent to a propylene-ethylene random copolymer prepared using a metallocene catalyst having a structure, leading to the present invention.

Accordingly, the present invention relates to a polypropylene prepared using a catalyst composition comprising a transition metal compound represented by the following formula (1); and a nucleating agent; wherein the polypropylene is a propylene homopolymer or a propylene-ethylene random copolymer, and the nucleating agent is a sorbitol-based nucleating agent or a nonitol-based nucleating agent.

[Formula 1]

In Formula 1, M is a Group 4 transition metal; Q ₁ and Q ₂ are each independently halogen, (C ₁ -C ₂₀ )alkyl, (C ₂ -C ₂₀ )alkenyl, (C ₂ -C ₂₀ )alkynyl, (C ₆ -C ₂₀ )aryl, ( C ₁ -C ₂₀ )alkyl, (C ₆ -C ₂₀ )aryl, (C ₆ -C ₂₀ )aryl(C ₁ -C ₂₀ )alkyl, (C ₁ -C ₂₀ )alkylamido, (C ₆ -C ₂₀ )arylamido or (C ₁ -C ₂₀ )alkylidene; R ₁ , R ₂ , R ₃ and R ₄ are each independently hydrogen; _{(C 1} -C ₂₀ )alkyl with or without acetal, ketal or ether groups; _{(C 2} -C ₂₀ )alkenyl with or without acetal, ketal or ether groups; _{(C 1} -C ₂₀ )alkyl(C ₆ -C ₂₀ )aryl with or without acetal, ketal or ether groups; _{(C 6} -C ₂₀ )aryl(C ₁ -C ₂₀ )alkyl with or without acetal, ketal or ether groups; _{or (C 1} -C ₂₀ )silyl with or without acetal, ketal or ether groups; at least two of R ₁ , R ₂ , R ₃ and R ₄ may be linked to each other to form an aliphatic ring or an aromatic ring; R ₅ , R ₆ , R ₇ and R ₈ are each independently hydrogen; _{(C 1} -C ₂₀ )alkyl with or without acetal, ketal or ether groups; _{(C 2} -C ₂₀ )alkenyl with or without acetal, ketal or ether groups; _{(C 1} -C ₂₀ )alkyl(C ₆ -C ₂₀ )aryl with or without acetal, ketal or ether groups; R ₉ , R ₁₀ , R ₁₁ , R ₁₂ , R ₁₃ , R ₁₄ , R ₁₅ and R ₁₆ are each independently hydrogen; _{(C 1} -C ₂₀ )alkyl with or without acetal, ketal or ether groups; _{(C 2} -C ₂₀ )alkenyl with or without acetal, ketal or ether groups; _{(C 1} -C ₂₀ )alkyl(C ₆ -C ₂₀ )aryl with or without acetal, ketal or ether groups; _{(C 6} -C ₂₀ )aryl(C ₁ -C ₂₀ )alkyl with or without acetal, ketal or ether groups; _{or (C 1} -C ₂₀ )silyl with or without acetal, ketal or ether groups; At least two of R ₉ , R ₁₀ , R ₁₁ , R ₁₂ , R ₁₃ , R ₁₄ , R ₁₅ and R ₁₆ may be linked to each other to form an aliphatic ring or an aromatic ring.

As used herein, the term “alkyl” refers to a monovalent straight-chain or branched saturated hydrocarbon radical composed only of carbon and hydrogen atoms, and examples of such alkyl radicals include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t- butyl, pentyl, hexyl, octyl, dodecyl, and the like.

In addition, as used herein, the term "cycloalkyl" refers to a monovalent alicyclic alkyl radical composed of one ring, and examples of cycloalkyl include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl. , cyclononyl, cyclodecyl, and the like.

In addition, as used herein, the term "alkenyl" refers to a straight-chain or branched hydrocarbon radical containing one or more carbon-carbon double bonds, and includes ethenyl, propenyl, butenyl, pentenyl, and the like, However, the present invention is not limited thereto.

In addition, the term "aryl" described in the present invention is an organic radical derived from an aromatic hydrocarbon by removal of one hydrogen, and includes a single or fused ring system. Specific examples include, but are not limited to, phenyl, naphthyl, biphenyl, anthryl, fluorenyl, phenanthryl, triphenylenyl, pyrenyl, peryleneyl, chrysenyl, naphthacenyl, fluoranthenyl, and the like.

In addition, as used herein, the term “alkoxy” refers to an —O-alkyl radical, where “alkyl” is as defined above. Examples of such alkoxy radicals include, but are not limited to, methoxy, ethoxy, isopropoxy, butoxy, isobutoxy, t-butoxy, and the like.

In addition, the term "halogen" as used herein means a fluorine, chlorine, bromine or iodine atom.

The transition metal compound is an ansa-metal containing a cyclopentadiene derivative ligand connected to each other by a bridge group of silicon or alkenylene and an indenyl derivative ligand in which an aryl is necessarily substituted at the 4th position, as shown in Formula 1 It has an ansa-metallocene structure.

As such, the transition metal compound has an indene derivative ligand substituted with an aryl at the 4th position, and thus has superior catalytic activity and copolymerizability compared to the transition metal compound having a ligand unsubstituted with an aryl group at the 4th position of the indene. .

Here, in the transition metal compound, in the structure of Formula 1 _{, at least one of R 1} , R ₂ , R ₃ and R ₄ is hydrogen, and the rest are each independently (C ₁ -C ₂₀ )alkyl, (C ₂ -C ₂₀ ) may be substituted with _{(C 1} -C ₂₀ )silyl with or without alkenyl, (C ₆ -C ₂₀ )aryl or acetal, ketal or ether groups _{, wherein R 1} , R ₂ , R ₃ and R _{It is preferable that two or more of 4} are connected to each other to form an aliphatic ring or an aromatic ring, and more preferably, at least two or more of _{R 1} , R ₂ , R ₃ and R _{4 are hydrogen, and the rest are} Independently of each other _{, when substituted with (C 1} -C ₂₀ )alkyl, it is possible to produce a propylene homopolymer or a propylene-ethylene random copolymer with improved transparency and rigidity, particularly during polymerization of olefins using propylene or ethylene as a monomer.

In addition, the metallocene catalyst extracts the ligand from the transition metal compound to cationize the central metal, and a counterion having weak binding force, that is, a compound containing a unit represented by the following formula (2), which can act as an anion, It may further include a cocatalyst compound containing at least one selected from the group consisting of a compound represented by 3 and a compound represented by the following formula (4).

[Formula 2]

-[Al(R ₁₇ )-O]n-

In Formula 2, R ₁₇ is the same as or different from each other and each independently represents a halogen radical or a hydrocarbyl radical having 1 to 20 carbon atoms substituted or unsubstituted with halogen; n is an integer greater than or equal to 2;

[Formula 3]

A(R ₁₈ )3

In formula (3), A is aluminum or boron; R ₁₈ is the same as or different from each other, and each independently represents a halogen radical or a hydrocarbyl radical having 1 to 20 carbon atoms substituted or unsubstituted with halogen.

[Formula 4]

[LH] ⁺ [Z(B) ₄ ] ^- or [L] ⁺ [Z(B) ₄ ] ^-

In formula (4), L is a neutral or cationic Lewis acid; H is a hydrogen atom; Z is a group 13 element; each B is independently an aryl or alkyl radical having 6 to 20 carbon atoms in which one or more hydrogen atoms are replaced by a halogen, hydrocarbyl, alkoxy, or phenoxy radical having 1 to 20 carbon atoms.

In order for the promoter compound to exhibit a better activation effect, the compound represented by Formula 2 is not particularly limited as long as it is an alkylaluminoxane, but preferred examples include methylaluminoxane, ethylaluminoxane, isobutylaluminoxane, butyl aluminoxane and the like, and a particularly preferred compound is methylaluminoxane.

In addition, the alkyl metal compound represented by Formula 3 is not particularly limited, but preferred examples thereof include trimethylaluminum, triethylaluminum, triisobutylaluminum, tripropylaluminum, tributylaluminum, dimethylchloroaluminum, triisopropylaluminum, and trimethylaluminum. -s-butyl aluminum, tricyclopentyl aluminum, tripentyl aluminum, triisopentyl aluminum, trihexyl aluminum, trioctyl aluminum, ethyl dimethyl aluminum, methyldiethyl aluminum, triphenyl aluminum, tri-p-tolyl aluminum, dimethyl aluminum methoxide, dimethylaluminum ethoxide, trimethylboron, triethylboron, triisobutylboron, tripropylboron, tributylboron, and the like, and particularly preferred compounds may be selected from trimethylaluminum, triethylaluminum and triisobutylaluminum. can

In addition, in the promoter compound represented by Formula 4, the [LH] ⁺ is a dimethylanilinium cation, the [Z(A) ₄ ] ^- is [B(C ₆ F ₅ ) ₄ ] ^- It is preferable that , wherein [L] ⁺ is [(C ₆ H ₅ ) ₃ C] ⁺ , and [Z(A) ₄ ] ^- is [B(C ₆ F ₅ ) ₄ ] ^- . Here, the promoter compound represented by Formula 4 is not particularly limited, but non-limiting examples include triethylammonium tetraphenylborate, tributylammonium tetraphenylborate, trimethylammonium tetraphenylborate, and tripropylammonium tetraphenyl. borate, trimethylammonium tetra(p-tolyl) borate, tripropylammonium tetra(p-tolyl) borate, trimethylammonium tetra(o,p-dimethylphenyl) borate, triethylammonium tetra(o,p-dimethyl Phenyl) borate, tributylammonium tetra(p-trifluoromethylphenyl) borate, trimethylammonium tetra(p-trifluoromethylphenyl) borate, tributylammonium tetrapentafluorophenyl borate, N,N-diethyl Amilidium tetrapetyl borate, N,N-diethylanilideium tetraphenylborate, N,N-diethylaniliniumtetrapentafluorophenylborate, diethylammoniumtetrapentafluorophenylborate, triphenylphosph Phoniumtetraphenylborate, trimethylphosphoniumtetraphenylborate, triphenylcarboniumtetra(p-trifluoromethylphenyl)borate, triphenylcarboniumtetrapentafluorophenylborate, dimethylaniliniumtetrakis(pentafluoro phenyl) borate.

In the present invention, among the propylene homopolymers or propylene-ethylene random copolymers prepared using the catalyst composition, both rigidity and transparency required for manufacturing film packaging materials and food storage containers through sheet molding or vacuum/pressure molding are satisfied. A propylene-ethylene random copolymer may be selected more preferably from the viewpoint of making the propylene-ethylene random copolymer more preferably selected, and the ethylene content of the propylene-ethylene random copolymer is 0.1 to 1.5% by weight, preferably 0.3 to 1.2% by weight, more preferably Preferably 0.5 to 1.0% by weight, even more preferably 0.6 to 0.8% by weight.

In addition, from the viewpoint of satisfying both rigidity and transparency required in the final resin composition, the propylene homopolymer or propylene-ethylene random copolymer has a melt index (230° C., 2.16 kg load) of 1 to 10 g/10 min, preferably 2 to 9 g/10 min, more preferably 3 to 8 g/10 min, even more preferably 5 to 7 g/10 min may be selected.

On the other hand, in the polypropylene resin composition of the present invention, as a specific nucleating agent, a sorbitol-based nucleating agent or a nonitol-based nucleating agent is added to the propylene homopolymer or propylene-ethylene random copolymer prepared using the specific metallocene catalyst. It allows the sheet formability or vacuum/pressure formability to be maintained as it is while dramatically improving transparency and rigidity.

As such a nucleating agent, as the sorbitol-based nucleating agent, for example, 1,3:2,4-bis(3,4-dimethylbenzylidene)sorbitol may be preferably used, and as the nonitol-based nucleating agent, for example, 1,2,3 -Trideoxy-4,6:5,7-bis-O-[(4-propylphenyl)methylene]-nonitol may be preferably used, and in order to maximize transparency and rigidity improvement of the final resin composition, 1, It is most preferred to select 3:2,4-bis(3,4-dimethylbenzylidene)sorbitol.

In the present invention, the nucleating agent is preferably contained in an amount of 0.1 to 0.5% by weight of the total resin composition, and as the nucleating agent content increases, the transparency and rigidity of the final resin composition may be improved, but in a range exceeding 0.5% by weight, the content The effect of improving transparency and rigidity according to the increase is insignificant, which is undesirable from an economic point of view.

In the present invention, the final polypropylene resin composition may be prepared according to a conventional method in the art, for example, the polypropylene prepared with the metallocene catalyst and the nucleating agent are mixed using an extruder, and then melt-kneaded. can

The polypropylene resin composition of the present invention contains one or more conventional additives known in the art as other additives other than the above components, for example, a slip agent, an anti-blocking agent, an antioxidant, a neutralizer, a UV stabilizer, an antistatic agent, etc. can do. At this time, each additive may be included in the range of 0.01 to 1 part by weight based on 100 parts by weight of the resin composition of the present invention.

The polypropylene resin composition according to the present invention can satisfy both rigidity and transparency required for manufacturing film packaging materials, food storage containers, etc. through sheet molding or vacuum molding, and furthermore, it can be provided with excellent heat resistance properties. . Specifically, the polypropylene resin composition according to the present invention has a tensile strength (ASTM D638 Type IV standard, 50 mm/min condition) of 350 kgf/cm 2 or more, preferably 380 kgf/cm 2 or more, and a flexural modulus (ASTM D790, 10 mm / min condition) is 15,000 kgf / cm or more, preferably 18,000 kgf / cm or more, and the haze (ASTM D1003, 1 mm thickness) is 8% or less, preferably 7% or less, The heat deflection temperature (HDT) (ASTM D648, 4.6 kg load) may be 100°C or higher, preferably 110°C or higher.

Hereinafter, the present invention will be described in more detail through specific Preparation Examples, Examples and Comparative Examples.

Preparation Example 1: Preparation of metallocene supported catalyst

Silica (manufacturer: Grace, product name: XPO-2412, 2.0 g) was placed in a Schlenk flask (100 ml) in a glove box, and then 10 ml of anhydrous toluene solution was added thereto. Herein, about 10.2 ml of methylaluminoxane (10% by weight solution of methylaluminoxane in toluene, 15 mmol based on Al, manufacturer: Albemarle) was slowly added dropwise at 10° C., and stirred at 0° C. for about 1 hour, and then 70 The temperature was raised to ℃, stirred for 3 hours, and cooled to 25℃. Separately, in a glove box, the transition metal compound (4-butyl-2-methylcyclopentadienyl dimethylsilyl 2-methyl-4-(4-t -butylphenyl)indenyl zirconium dichloride (4-butyl-2-methylcyclopentadienyl dimethylsilyl 2-methyl-4-(4- t- butylphenyl)indenyl Zr dichloride)) (0.060 g, 100 μmol) was placed in another 100 ml Schlenk flask, taken out of the glove box, and then 10 ml of anhydrous toluene solution was added. Here, the solution containing the transition metal compound at 10° C. was slowly added to the solution containing silica and methylaluminoxane, and then the temperature was raised to 70° C. and stirred for 1 hour, then cooled to 25° C. for about 24 hours. stirred for a while. After that, the obtained reaction product was dried in vacuum to obtain 2.70 g of a free-flowing supported catalyst.

Preparation Example 2: Preparation of polypropylene using metallocene catalyst

The inside of a stainless steel autoclave having an internal capacity of 2 L at room temperature was completely replaced with nitrogen. While maintaining nitrogen purging, triisobutylaluminum (2 ml of a 1M solution in hexane), 500 g of propylene, and ethylene were injected into the reactor to the final content shown in Table 1 below, and then in Preparation Example 1 50 mg of the prepared supported catalyst compound was dispersed in 5 ml of hexane and added to the reactor using high pressure nitrogen. Thereafter, polymerization was carried out at 70° C. for 60 minutes. After the polymerization was completed, the reactor was cooled to room temperature, and excess propylene was removed through a discharge line to obtain a white powdery solid. The obtained white solid powder was dried for at least 15 hours while heating to 80°C using a vacuum oven, and the final propylene homopolymer or propylene-ethylene random copolymer having the melt index (ASTM D1238, 230°C, 2.16 kg load) of Table 1 below. was prepared.

Examples 1 to 8

Polypropylene having a melt index and ethylene content shown in Table 1 below and a nucleating agent having the composition shown in Table 1 (sorbitol-based nucleating agent: 1,3:2,4-bis(3,4-dimethylobenzylideno)sorbitol, nonitol-based nucleating agent: After mixing with a Hensel mixer using 1,2,3-Trideoxy-4,6:5,7-bis-O-[(4-propylphenyl)methylene]-nonitol), the mixture was 40 mmΦ single Polypropylene resin composition in the form of pellets was prepared by melt extrusion molding with an extruder (screw rotation speed of 100 to 120 rpm, C1/C2/C3/C4/D=180/200/210/220/210°C conditions) did.

Comparative Examples 1 to 6

Polymerized using a commercial Ziegler-Natta catalyst (solid catalyst component consisting of magnesium, titanium and bromine, triethyl aluminum as a co-catalyst and diethyl phthalate as an internal electron donor), melt index (MI ) (ASTM D1238, 230°C, load 2.16 kg) and propylene-ethylene random copolymer having an ethylene content and a nucleating agent of the composition shown in Table 1 below (sorbitol-based nucleating agent: 1,3:2,4-bis(3,4) -dimethylobenzylideno)sorbitol, nonitol-based nucleating agent: 1,2,3-Trideoxy-4,6:5,7-bis-O-[(4-propylphenyl)methylene]-nonitol) was mixed with a Hensel mixer, This mixture was melt-extruded with a 40 mmΦ single extruder (screw rotation speed of 100-120 rpm, temperature of 180-220° C.) to prepare a polypropylene resin composition in the form of pellets.

Test Example 1

For the polypropylene resin composition prepared above, an injection specimen for measuring ASTM properties was prepared, and tensile strength, flexural modulus, heat deflection temperature and cloudiness were measured according to the following method, and the results are shown in Table 1 below.

[How to measure]

(1) Tensile strength

It was measured under 50 mm/min condition according to ASTM D638 Type IV standard.

(2) Flexural modulus

It was measured under 10 mm/min condition according to ASTM D790.

(3) Heat Deflection Temperature (HDT)

Measured under 4.6 kg load according to ASTM D648.

(4) Haze

Measurements were made on 1 mm and 2 mm thick specimens according to ASTM D1003.

Test Example 2

The polypropylene resin compositions prepared according to Examples 1 to 5 and Comparative Examples 1 and 2 were put into a single-layer sheet forming machine, and the screw temperature was 180 to 215° C., the roll speed was 2.4 m/min, the winding speed was 5.0 Nm, and the die Form a sheet with a thickness of 0.4 mm under the conditions of roll temperature (T1/T2) 80°C and chiller temperature 8°C, and melt pressure during sheet molding (measuring the pressure of the melted resin discharged from the front of the die of the sheet molding machine with a sensor) , screw speed and haze were measured for the molded sheet, and the results are shown in Table 2 below.

Item Comparative Example 2 Comparative Example 3 Example 1 Example 2 Example 3 Example 4 Example 5 melt pressure
(bar) 81 80 71 71 79 80 81 screw speed
(rpm) 170 170 160 160 170 170 170 Sheet Haze
(0.4mmT%) 3.3 2.7 1.7 2.1 2.1 2.4 2.4

Referring to Tables 1 and 2, when a sorbitol-based nucleating agent is applied as a specific nucleating agent to the polypropylene prepared using the metallocene catalyst composition including the transition metal compound of Formula 1 according to the present invention (Example 1) to 8) The effect of improving the rigidity while maintaining a certain level of transparency is excellent, and when a propylene-ethylene random copolymer is applied, when the ethylene content is preferred (Examples 2 to 5), the resin composition most suitable for the purpose of the present invention It is possible to manufacture, and when weight is given to rigidity in the balance of physical properties of rigidity and transparency, it is preferable to use a sorbitol-based nucleating agent (Example 5) rather than a nonitol-based nucleating agent (see Examples 2 to 4) in using the nucleating agent. can be checked

In contrast, when the specific nucleating agent presented in the present invention is added to a propylene-ethylene random copolymer prepared using a conventional Ziegler-Natta catalyst and containing a typical ethylene content (2 to 3 wt%) (Comparative Examples 1 to 5) ) In most cases, both rigidity and transparency are not good, and when using a propylene-ethylene random copolymer containing an ethylene content in the preferred content presented in the present invention (Comparative Example 6), the rigidity is improved, but it is at the level desired in the present invention in terms of transparency. It can be seen that there is not much

Preferred embodiments of the present invention described above are disclosed to solve the technical problem, and various modifications, changes, additions, etc. will be possible within the spirit and scope of the present invention by those skilled in the art to which the present invention pertains. , such modifications and changes should be regarded as belonging to the following claims.

Claims (6)

Polypropylene prepared by using a catalyst composition comprising a transition metal compound represented by the following formula (1); and a nucleating agent;
The polypropylene resin composition is a propylene homopolymer or a propylene-ethylene random copolymer, and the nucleating agent is a sorbitol-based nucleating agent or a nonitol-based nucleating agent:
[Formula 1]

In Formula 1, M is a Group 4 transition metal;
Q ₁ and Q ₂ are each independently halogen, (C ₁ -C ₂₀ )alkyl, (C ₂ -C ₂₀ )alkenyl, (C ₂ -C ₂₀ )alkynyl, (C ₆ -C ₂₀ )aryl, ( C ₁ -C ₂₀ )alkyl, (C ₆ -C ₂₀ )aryl, (C ₆ -C ₂₀ )aryl(C ₁ -C ₂₀ )alkyl, (C ₁ -C ₂₀ )alkylamido, (C ₆ -C ₂₀ )arylamido or (C ₁ -C ₂₀ )alkylidene;
R ₁ , R ₂ , R ₃ and R ₄ are each independently hydrogen; _{(C 1} -C ₂₀ )alkyl with or without acetal, ketal or ether groups; _{(C 2} -C ₂₀ )alkenyl with or without acetal, ketal or ether groups; _{(C 1} -C ₂₀ )alkyl(C ₆ -C ₂₀ )aryl with or without acetal, ketal or ether groups; _{(C 6} -C ₂₀ )aryl(C ₁ -C ₂₀ )alkyl with or without acetal, ketal or ether groups; _{or (C 1} -C ₂₀ )silyl with or without acetal, ketal or ether groups; at least two of R ₁ , R ₂ , R ₃ and R ₄ may be linked to each other to form an aliphatic ring or an aromatic ring;
R ₅ , R ₆ , R ₇ and R ₈ are each independently hydrogen; _{(C 1} -C ₂₀ )alkyl with or without acetal, ketal or ether groups; _{(C 2} -C ₂₀ )alkenyl with or without acetal, ketal or ether groups; _{(C 1} -C ₂₀ )alkyl(C ₆ -C ₂₀ )aryl with or without acetal, ketal or ether groups;
R ₉ , R ₁₀ , R ₁₁ , R ₁₂ , R ₁₃ , R ₁₄ , R ₁₅ and R ₁₆ are each independently hydrogen; _{(C 1} -C ₂₀ )alkyl with or without acetal, ketal or ether groups; _{(C 2} -C ₂₀ )alkenyl with or without acetal, ketal or ether groups; _{(C 1} -C ₂₀ )alkyl(C ₆ -C ₂₀ )aryl with or without acetal, ketal or ether groups; _{(C 6} -C ₂₀ )aryl(C ₁ -C ₂₀ )alkyl with or without acetal, ketal or ether groups; _{or (C 1} -C ₂₀ )silyl with or without acetal, ketal or ether groups; At least two of R ₉ , R ₁₀ , R ₁₁ , R ₁₂ , R ₁₃ , R ₁₄ , R ₁₅ and R ₁₆ may be linked to each other to form an aliphatic ring or an aromatic ring. According to claim 1,
The propylene-ethylene random copolymer has an ethylene content of 0.1 to 1.5% by weight, and the polypropylene has a melt index (230° C., 2.16 kg load) of 1 to 10 g/10min. According to claim 1,
The sorbitol-based nucleating agent includes 1,3:2,4-bis (3,4-dimethylobenzylideno) sorbitol (1,3:2,4-bis (3,4-dimethylobenzylideno) sorbitol), and the noni Toll-based nucleating agent 1,2,3-trideoxy-4,6:5,7-bis-O-[(4-propylphenyl)methylene]-nonitol (1,2,3-Trideoxy-4,6: 5,7-bis-O-((4-propylphenyl)methylene)-nonitol) polypropylene resin composition. According to claim 1,
The nucleating agent is a polypropylene resin composition, characterized in that 0.1 to 0.5% by weight of the total resin composition. According to claim 1,
The resin composition has a tensile strength (ASTM D638 Type IV standard, 50 mm/min condition) of 350 kgf/cm2 or more, a flexural modulus (ASTM D790, 10 mm/min condition) of 15,000 kgf/cm2 or more, and a cloudiness ( Haze) (ASTM D1003, based on 1 mm thickness) of 8% or less polypropylene resin composition. 6. The method according to any one of claims 1 to 5,
The resin composition is a polypropylene resin composition, characterized in that the sheet or for vacuum and pressure.