KR20180027673A - Polypropylene resin composition for blow molded article integrated with handle and preparing method same - Google Patents

Abstract

Disclosed are a polypropylene resin composition for molding a hollow integrated with a handle and a manufacturing method thereof which have excellent transparency and excellent impact features while molding an integrated hollow having a handle. The polypropylene resin composition for molding a hollow integrated with a handle comprises: 80-98 weight% of a block copolymer made by blocks of 80-95 weight% of a first copolymer and 5-20 weight% of a second copolymer wherein the first copolymer is made by copolymerizing 90-98 weight% of propylene, 1-5 weight% of ethylene, and 1-5 weight% of 1-butene and the second copolymer is made by copolymerizing 60-85 weight% of propylene, 10-35 weight% of ethylene, and 1-5 weight% of 1-butene; and 2-10 weight% of linear low density polyethylene wherein a melting index of the linear low density polyethylene is 0.5-3.0 g/10 min at 190°C and density of the linear low density polyethylene is 0.91-0.93 g/cm^3.

Description

TECHNICAL FIELD [0001] The present invention relates to a polypropylene resin composition for blow molding, and a method for producing the same. BACKGROUND ART < RTI ID = 0.0 >

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polypropylene resin composition for blow molding and a method of manufacturing the same. More particularly, the present invention relates to a polypropylene resin composition for blow molding with a handle and a method of manufacturing the same.

Currently, most of the hollow molding containers for storing detergents are made of high density polyethylene (HDPE). HDPE for blow molding has a high melt viscosity and is easy to process and has a low impact strength at low temperature. However, since the content is not visible due to opaque material, aesthetic property is deteriorated. Polyethylene terephthalate (PET) is mainly used for transparent containers, but it is impossible to perform integral blow molding with a handle, so a method of manufacturing and assembling the handle is used.

On the other hand, polypropylene (PP) resin is transparent compared to HDPE and has advantages of easy manufacture of integral container compared to PET resin, but it is not suitable for application of medium or more containers due to insufficient impact strength at room temperature and low temperature. In order to improve the impact strength at room temperature, it is possible to prepare an additional metallocene-based polyolefin elastomer in the production of a middle- or large-sized container using a transparent PP, but a cost increase is inevitable.

Korean Patent Laid-Open Publication No. 2016-0039405 discloses a polypropylene random block copolymer characterized in that the ethylene-propylene block copolymer is finely dispersed in an ethylene-propylene random copolymer or an ethylene-propylene-? -Olefin ternary random copolymer However, the melt viscosity, transparency and impact resistance characteristics suitable for a hollow molded container with a knob are insufficient.

Korean Patent No. 1185710 discloses a polypropylene composition having excellent impact resistance and transparency, but has a problem in that it is not suitable for use in a product in which the transparency is insufficient and the clarity of the liquid inside the molded article is important.

Disclosed is a polypropylene resin composition for blow molding, which is capable of monolithic blow molding with a handle and is excellent in transparency and impact properties, and a process for producing the same.

(A) 80 to 95% by weight of a first copolymer comprising 90 to 98% by weight of propylene, 1 to 5% by weight of ethylene and 1 to 5% by weight of 1-butene, And 5 to 20% by weight of a second copolymer obtained by copolymerizing 60 to 85% by weight of propylene, 10 to 35% by weight of ethylene and 1 to 5% by weight of 1-butene, 80 to 98% by weight of a block copolymer %; And (b) 2 to 10% by weight of a linear low density polyethylene resin having a melt index (190 占 폚, 2.16 kg) of 0.5 to 3.0 g / 10 min and a density of 0.91 to 0.93 g / cm3. Propylene resin composition.

The polypropylene resin composition preferably has a melt index of 0.1 to 4 g / 10 min (230 DEG C, 2.16 kg ). ≪ / RTI >

The propylene-based composition had a haze (ASTM D1003) of less than 20%, a DuPont impact strength (23 캜, kg · cm) of N / B (Not Breakable), a DuPont impact strength , kg · cm) is 60 to 150 g / 10 cm2. The polypropylene resin composition for integral blow molding is characterized in that

According to another aspect of the present invention, there is provided a process for producing a copolymer comprising: (A) forming a first copolymer of 90 to 98% by weight of propylene, 1 to 5% by weight of ethylene and 1 to 5% by weight of 1-butene; (B) a second copolymer of 60 to 85 wt.% Propylene, 10 to 35 wt.% Ethylene and 1 to 5 wt.% 1-butene in the presence of said first copolymer is blocked with said first copolymer Forming a block copolymer; And (C) 80 to 98% by weight of the block copolymer, 2 to 10 parts by weight of a linear low density polyethylene resin having a melt index (190 占 폚, 2.16 kg) of 0.5 to 3.0 g / 10 min and a density of 0.91 to 0.93 g / (Ethylene / propylene / 1-butene) of 0.2 to 0.3 and a ratio of (hydrogen / ethylene) of 0.1 to 0.5, Of the polypropylene resin composition for blow molding according to the present invention.

The present invention relates to a composition comprising a block copolymer block copolymer having an optimum composition and a linear low density polyethylene resin having an optimum composition, wherein the propylene / alpha olefin terpolymer and the block copolymer are produced in a continuous process, There can be provided a polypropylene resin composition for kneading monolithic blow molding capable of monolithic hollow molding while improving melt viscosity, improving impact strength and transparency, and reducing surface elution, and a method for producing the same.

Hereinafter, preferred embodiments of the present invention will be described in detail. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. Throughout the specification, when an element is referred to as "including " an element, it means that it can include other elements, not excluding other elements, unless specifically stated otherwise.

The present inventors have found that a first copolymer of propylene / ethylene / 1-butene of a specific composition and a second copolymer of propylene / ethylene / 1-butene of the first copolymer and another specific composition of the first copolymer are mixed with the first copolymer It has been found that a polypropylene resin mixed with a block copolymer and a linear low density polyethylene resin having a specific composition can be suitably used for a large-capacity kneading-type blow molding, while improving melt viscosity, improving impact strength and transparency and reducing surface elution Leading to the present invention.

Accordingly, the present invention provides a thermoplastic resin composition comprising (a) 80 to 95% by weight of a first copolymer of 90 to 98% by weight of propylene, 1 to 5% by weight of ethylene and 1 to 5% From 5 to 20% by weight of a second copolymer of propylene, from 10 to 35% by weight of ethylene and from 1 to 5% by weight of 1-butene, from 80 to 98% by weight of a block copolymer block; And (b) 2 to 10% by weight of a linear low density polyethylene resin having a melt index (190 占 폚, 2.16 kg) of 0.5 to 3.0 g / 10 min and a density of 0.91 to 0.93 g / cm3. A propylene resin composition is disclosed.

The polypropylene resin composition according to the present invention can be prepared through a process in which a second copolymer forms a block with a first copolymer in the presence of a first copolymer and then a linear low density polyethylene resin is mixed therewith. The present invention will be described in detail.

(A) a first copolymer of propylene, 1 to 5% by weight of ethylene and 1 to 5% by weight of 1-butene in an amount of 90 to 98% by weight, ; (B) a second copolymer of 60 to 85 wt.% Propylene, 10 to 35 wt.% Ethylene and 1 to 5 wt.% 1-butene in the presence of said first copolymer is blocked with said first copolymer Forming a block copolymer; And (C) 80 to 98% by weight of the block copolymer, 2 to 10 parts by weight of a linear low density polyethylene resin having a melt index (190 占 폚, 2.16 kg) of 0.5 to 3.0 g / 10 min and a density of 0.91 to 0.93 g / (Ethylene / propylene / 1-butene) of 0.2 to 0.3 and a ratio of (hydrogen / ethylene) of 0.1 to 0.5, . ≪ / RTI >

When the content of monomers and hydrogen used in the block copolymer preparation is adjusted to the above specific range, the intrinsic viscosity ratio of the first copolymer and the second copolymer is lowered to less than 1, and thus the copolymer exhibits improved compatibility and dispersibility And can exhibit excellent transparency and impact resistance at the same time. In addition, by forming the block copolymer without simple mixing or kneading of the first copolymer and the second copolymer, the impact resistance can be maximized while maintaining transparency.

According to an embodiment of the present invention, the step of forming the first copolymer may be carried out by bulk polymerization or gas phase polymerization, preferably by bulk polymerization, and the first copolymer and the second copolymer may block The step of forming the finished block copolymer can be carried out by gas phase polymerization. Such a series of bulk polymerization and gas phase polymerization can precisely control the composition of the block copolymer to be produced, thereby making it possible to produce a block copolymer satisfying all of the following physical properties.

The first copolymerization step can be carried out by bulk polymerization, wherein the bulk polymerization can be carried out sequentially in two or more successive bulk reactors. When the bulk polymerization is carried out in two consecutive bulk reactors, the operating conditions of each reactor may be the same or different. In the bulk reactor, propylene, ethylene, 1-butene, a catalyst system and hydrogen are continuously supplied as polymerization reaction raw materials. Hydrogen may be added to control the molecular weight and physical properties of the copolymer.

At the beginning of the reaction in the bulk polymerization, a propylene / ethylene copolymer, a propylene / 1-butene copolymer, a propylene / ethylene / 1-butene terpolymer or the like may be produced and finally the first copolymer is formed.

In the first copolymerization step, the feed amount of each monomer is adjusted to the desired composition (90 to 98% by weight of propylene, 1 to 5% by weight of ethylene and 1 to 5% by weight of 1-butene) . ≪ / RTI >

The catalyst system to be added to the first copolymerization step may be any one generally used in the art to which the present invention pertains. Therefore, it is preferable to use a catalyst system including a Ziegler-Natta catalyst, .

The catalyst system may include a Ziegler-Natta solid catalyst, an organoaluminum compound and an electron donor compound, and it is preferable to use a highly active solid catalyst having a polymerization amount of 20 kg or more per 1 g of the catalyst in consideration of the reaction efficiency. Further, it is more preferable to use a catalyst system having a high stereoregularity with a pentad isotactic index of 92% by weight or more measured by nuclear magnetic resonance (MRI) in the production of homopolypropylene using the above catalyst system .

As the organoaluminum compound in the catalyst system, it is preferable to use a trialkylaluminum compound, more preferably trimethylaluminum, triethylaluminum, tripropylaluminum, , Tributyl aluminum, or the like can be used.

As the electron donor compound in the catalyst system, it is preferable to use an alkoxysilane compound, more preferably cyclohexylmethyldimethoxysilane, dicyclopentyldimethoxysilane, diisopropenyldimethoxysilane, Diisopropyldimethoxysilane and the like can be used.

Meanwhile, it is preferable that the step of forming the first copolymer is performed at a temperature of 50 to 80 ° C. That is, the bulk polymerization temperature is preferably 50 ° C or higher so as to obtain a minimum polymerization reaction rate. However, if the temperature is too high, the solubility of ethylene and hydrogen in the reactant may be low, which may make it difficult to control the composition of the copolymer, and the cohesion of the copolymer becomes large, which can cause process troubles. Therefore, the bulk polymerization temperature is preferably 80 DEG C or lower.

Also, the step of forming the first copolymer may be performed at a pressure of 20 kgf / cm 2 or more, preferably 20 to 50 kgf / cm 2. That is, the bulk polymerization pressure is preferably 20 kgf / cm 2 or more in order to increase the solubility of the reactants and improve the reaction efficiency.

Also, it is preferable that the average residence time in the reactor is adjusted to 0.5 to 2 hours in consideration of the physical properties of the first copolymer and the polymerization reaction efficiency.

The first copolymer formed through the above process is a copolymer of 90 to 98% by weight of propylene, 1 to 5% by weight of ethylene and 1 to 5% by weight of 1-butene, Can be given.

Here, when the content of ethylene and 1-butene is low, the crystallinity of the first copolymer is increased and the transparency of the produced block copolymer may be lowered. Therefore, the content of ethylene and 1-butene copolymerized in the first copolymer should be 1 wt% or more, respectively. However, when ethylene and 1-butene are used excessively in the formation of the first copolymer, the crystallinity of the first copolymer is lowered and the rigidity of the block copolymer may be lowered. Therefore, the content of ethylene and 1-butene copolymerized in the first copolymer should be 5 wt% or less, respectively.

Thus, the feed amount of each monomer in the step of forming the first copolymer is such that the desired composition of the first copolymer (90 to 98% by weight of propylene, 1 to 5% by weight of ethylene and 1 to 5% 1-butene).

In the step of forming the block copolymer of the first copolymer and the second copolymer, a second copolymer is formed by polymerization of propylene, ethylene and 1-butene continuously supplied in the presence of the first copolymer, The second copolymer forms a block copolymer with the first copolymer. At this time, hydrogen is added to control the molecular weight and physical properties of the copolymer.

In the step of forming the block copolymer, the amount of each monomer to be fed is selected in accordance with the desired composition of the second copolymer (60 to 85 wt% of propylene, 10 to 35 wt% of ethylene and 1 to 5 wt% of 1-butene) The content ratio of the first copolymer and the second copolymer, and the physical properties of the product of the block copolymer.

In particular, in the present invention, the molar ratio of [ethylene / (ethylene / propylene + 1-butene)] to the total amount of monomers charged to form the second copolymer in the above step is adjusted to 0.2 to 0.3. In addition, the molar ratio of hydrogen (hydrogen / ethylene) introduced in the above step may be adjusted to 0.1 to 0.5, preferably 0.2 to 0.4. In the case where any one of the molar ratio of [ethylene / (ethylene + propylene + 1-butene)] and the molar ratio of (hydrogen / ethylene) can not be satisfied, the block copolymer . Particularly, when the molar ratio of [ethylene / (ethylene + propylene + 1-butene)] is less than 0.2, it is difficult to form an amorphous part in the block copolymer and transparency is good. However, drop impact strength remarkably decreases. The density difference between the second copolymer and the first copolymer is generated, and the impact strength is high, but the transparency is drastically reduced.

In addition, the step of forming the block copolymer is performed such that 80 to 95 wt% of the first copolymer and 5 to 20 wt% of the second copolymer form a block. That is, the second copolymer should be contained in an amount of 5 to 20% by weight in order to impart an improved impact resistance to the block copolymer but prevent a decrease in transparency.

Also, the step of forming the block copolymer is preferably performed at a temperature of 60 to 90 ° C. and a pressure of 10 to 30 kgf / cm 2 in consideration of the reaction efficiency and the flowability of the reactant.

Also, in the step of forming the block copolymer, the average residence time in the reactor is preferably adjusted to 0.5 to 2 hours in consideration of the physical properties of the final product and the polymerization reaction efficiency.

In the present invention, the block copolymer may be formed by separately forming the first copolymer and the second copolymer separately from each other, and then block copolymerizing the first and second copolymers. However, It is advantageous in terms of production efficiency and securing the physical properties of the block copolymer to simultaneously form the second copolymer and block copolymerization.

The second copolymer formed in the step of forming the block copolymer is a copolymer of 60 to 85% by weight of propylene, 10 to 35% by weight of ethylene and 1 to 5% by weight of 1-butene, Thereby imparting improved impact resistance to the resin composition and enabling the expression of excellent transparency.

The second copolymer is obtained by polymerizing monomers of the same kind as the first copolymer. The second copolymer is excellent in compatibility between the copolymers and can maintain excellent transparency in the process of molding the block copolymer.

Also, the second copolymer has a relatively high crystallinity and high elasticity due to its high content of ethylene compared with the first copolymer, thus enabling the expression of hot shock resistance at low temperatures. However, when ethylene is excessively used in the formation of the second copolymer, the compatibility with the first copolymer is lowered and the transparency of the block copolymer may be lowered. Therefore, the content of ethylene copolymerized in the second copolymer should be not more than 35% by weight.

Particularly, according to the embodiment of the present invention, the intrinsic viscosity (eta 2 / eta 1) of the first copolymer (eta 1) and the second copolymer (eta 2) measured at 135 deg. 0.9, preferably from 0.6 to 0.8. The block copolymer may have a melt index of 0.5 to 3.0 g / 10 min (230 ° C, 2.16 kg). The intrinsic viscosity and the melt index are physical properties related to the compatibility and dispersibility of the first and second copolymers. When applied to a molded article using the final polypropylene resin composition, particularly, a kneaded hollow molded article having excellent transparency and impact resistance . Specifically, when the intrinsic viscosity ratio is less than 0.5, drop impact strength may be significantly deteriorated. When the intrinsic viscosity ratio is more than 0.9, the size of the rubber in the block copolymer may increase, resulting in a decrease in dispersibility and a decrease in transparency.

On the other hand, the block copolymer formed by the above method is a block copolymer of a first copolymer and a second copolymer satisfying the above-mentioned properties, and exhibits excellent transparency and excellent transparency through synergism by the block copolymerization of the terpolymers. It shows impact.

The linear low density polyethylene resin is an ethylene-alpha olefin copolymer and is mixed with the block copolymer to reduce the surface elution as well as improving impact strength and transparency in the final polypropylene resin composition. When the content is less than 2% by weight The effect of improving the melt viscosity and drop impact strength of the composition is insignificant. If it exceeds 10% by weight, the compatibility with the block copolymer is lowered, and transparency is remarkably reduced, which is not preferable. Such a linear low density polyethylene resin may be a commonly used Ziegler Natta catalyst or a product prepared using a metallocene catalyst.

The linear low density polyethylene resin may be kneaded with the block copolymer by a method commonly known in the art, for example, a single screw extruder or a twin screw extruder to produce a final polypropylene resin composition.

The polypropylene resin composition finally formed by combining the above components preferably has a melt index in the range of 0.1 to 4 g / 10 min (230 DEG C, 2.16 kg). If the melt index of the resin composition is less than 0.1 g / 10 min, the production may be difficult due to difficulty in production in a commercial manufacturing process. If the melt index exceeds 4 g / 10 min, the melt viscosity is decreased, can do.

In addition, the polypropylene resin composition according to the present invention has excellent transparency and impact properties, and may have a haze (ASTM D1003) of less than 20%, preferably less than 15%, and a Dupont impact strength (23 캜, kg · cm) is N / B (Not Breakable) and the DuPont impact strength (0 ° C, kg · cm) is 60 to 150 g / 10 cm 2, preferably 80 to 130 g / 10 cm 2.

The polypropylene resin composition according to the present invention may contain 0.1 to 0.4 parts by weight of a nucleating agent per 100 parts by weight of the resin composition in order to further improve transparency. The nucleating agent may be, for example, a sorbitol compound, a nonitol compound or a sodium phosphate compound, but is not particularly limited thereto.

The propylene-based composition according to the present invention may contain an antioxidant, a catalyst neutralizing agent, an antistatic agent, and the like which are generally used in the case of applying the kneader-integrated blow molding, in addition to the above components. If necessary, Additives such as heat stabilizers, weather stabilizers, lubricants, slip agents, flame retardants, pigments, dyes and the like can be used in combination.

Hereinafter, the present invention will be described in more detail with reference to Examples. In the following Examples and Experimental Examples, evaluation items and measurement methods of physical properties are as follows.

1) Melt index: measured at 230 DEG C under a load of 2.16 kg according to ASTM D1238.

2) Ethylene and 1-butene content: Determined by spectroscopic method using infrared absorption spectrum (FT-IR).

3) Melting point (Tm): Measured using a differential scanning calorimeter (DSC).

4) Intrinsic viscosity: Measured in a decalin solvent at 135 ° C.

5) Haze: A 1 mm thick specimen was prepared and measured according to the method of ASTM D1003.

6) IZOD impact strength: measured using Notched specimens according to the method of ASTM D256.

7) DUPONT Impact Strength: When the resin composition was injection molded with a specimen of 2 mm thickness and dropped at a limited height, the minimum height at which the specimen was broken and the maximum height (at 5 cm intervals) .

Impact Energy (kg · cm) = weight (kg) × falling height (cm)

8) Vessel Drop Impact Strength: The container was filled with 2.7L of water, then dropped at a height of 120 cm, and whether the container was broken or not was judged as 'O' or 'X' according to the breakage.

9) Moldability: Molding is performed by extrusion of parison with EBM molding machine, molding by injection molding of 2.7L handle, and 'O' when there is no molding defects such as thickness irregularity, When it occurred, it was evaluated as 'X'.

Example 1

(Bulk polymerization step)

Two bulk reactors were used. First, a Ziegler-Natta solid catalyst, triethylaluminum and cyclohexylmethyldimethoxysilane were fed to the first bulk reactor via a prepolymerization process with propylene and hydrogen. At this time, the first bulk reactor was further fed with propylene, ethylene, 1-butene and hydrogen to proceed the polymerization reaction. The composition in the first bulk reactor was continuously transferred to the second bulk reactor and the polymerization reaction was further conducted by feeding propylene, ethylene, 1-butene and hydrogen to the second bulk reactor. Specific operating conditions are as follows.

In the first bulk reactor, liquid propylene, gaseous ethylene and liquid 1-butene were fed at a constant rate, and solid catalyst (loading ratio of titanium as active ingredient: 3.0 wt%), triethylaluminum, cyclohexylmethyldimethoxysilane Respectively. In the second bulk reactor, propylene, ethylene and 1-butene were also fed at a constant rate. The two bulk reactors were maintained at a temperature of 60 ° C and a pressure of 35 kgf / cm 2, respectively. Hydrogen was supplied to the two reactors to maintain a hydrogen concentration of 1,000 ppm for molecular weight control. The sum of the average residence times of the two reactors It was about 1.6 hours.

The first copolymer prepared through the above process was supplied to the first flash drum, separated from the unreacted gas component, and transferred to the gas phase reactor continuously.

(Gas phase polymerization step)

In the presence of the first copolymer in the gas phase reactor, the second copolymer is further polymerized by feeding propylene, ethylene, 1-butene and hydrogen, and the polymerized slurry copolymer is passed through a second flash drum and a dryer Unreacted gas was separated to prepare a block copolymer having the composition shown in Table 1 below, in which the first and second copolymers were blocked.

At this time, the gas phase reactor was operated at a temperature of 75 ° C and a pressure of 14 kgf / cm 2, and propylene, ethylene, 1-butene and hydrogen introduced into the gas phase reactor were introduced into the gas phase. Then, ethylene was supplied so that the molar ratio of [ethylene / (ethylene + propylene + 1-butene)] was 0.25 and the molar ratio of hydrogen (hydrogen / ethylene) was 0.3. The residence time of the gas phase reactor was about 0.7 hours, and the average reaction amount at the end of polymerization was (60,000 g of copolymer) / (g catalyst).

(Kneading step and production of injection specimen and container)

The linear low density polyethylene resin (1-butene content: 5% by weight) was mixed with the antioxidant, the transparent nucleating agent and the catalyst neutralizing agent in the composition shown in the following Table 1 and mixed with a Henschel mixer for 10 minutes Extruded in a twin extruder at 190 to 250 ° C., cooled and solidified to prepare a polypropylene resin in the form of a pellet. The pellets were used to prepare specimens, and extrusion blow molding was performed using the pellets A 1.8 liter handle integrated container was prepared.

Example  2, Comparative Example  1 to 4

In the same manner as in Example 1 except that the amounts of reactants to be fed into the respective reactors were controlled so as to produce the resin compositions having the compositions shown in Table 1 in the bulk polymerization, gas phase polymerization and kneading steps of Example 1, poly Propylene resin was prepared and a specimen and a container were prepared in the same manner as in Example 1. [

Experimental Example

The properties of each injection specimen and container prepared according to the above Examples and Comparative Examples were measured according to the above-mentioned method, and the results are shown in Table 1 below.

As shown in Table 1, according to the present invention, the compositions and weight ratios of the first copolymer, the second copolymer and the linear low density polyethylene and the second copolymer relative to the first copolymer fall within the optimum range, Strength and excellent transparency, and it was confirmed that the hollow molded product had excellent moldability and drop impact strength.

On the other hand, when the ethylene content of the second copolymer is high (Comparative Example 1) and the intrinsic viscosity ratio is high (Comparative Example 2), excellent drop impact strength is exhibited but the degree of fogging is high, (Comparative Example 3) and the low intrinsic viscosity ratio (Comparative Example 4), the fogging is excellent but the impact strength is low, which causes a problem of breakage in the drop test after molding, which is unsuitable for commercial application. Also, in Comparative Example 4, the melt index is high and the melt viscosity is low, so that a thickness variation occurs during molding, and the container is broken at the time of blowing, which is unsuitable for the blow molding.

The preferred embodiments of the present invention have been described in detail above. It will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Accordingly, the scope of the present invention is defined by the appended claims rather than the foregoing detailed description, and all changes or modifications derived from the meaning, range, and equivalence of the claims are included in the scope of the present invention Should be interpreted.

Claims (4)

(a) 80 to 95% by weight of a first copolymer with 90 to 98% by weight of propylene, 1 to 5% by weight of ethylene and 1 to 5% by weight of 1-butene, 60 to 85% by weight of propylene, From 5 to 20% by weight of a second copolymer wherein 10 to 35% by weight of ethylene and 1 to 5% by weight of 1-butene are copolymerized, 80 to 98% by weight of a block copolymer block; And
(b) 2 to 10% by weight of a linear low density polyethylene resin having a melt index (190 占 폚, 2.16 kg) of 0.5 to 3.0 g / 10 min and a density of 0.91 to 0.93 g / cm3;
Wherein the polypropylene resin composition is a polypropylene resin composition. The method according to claim 1,
The polypropylene resin composition has a melt index of 0.1 to 4 g / 10 min (230 DEG C, 2.16 kg), and the polypropylene resin composition has an intrinsic viscosity ratio of 0.5 to 0.9, Wherein the polypropylene resin composition is a polypropylene resin composition. 3. The method of claim 2,
The propylene-based composition had a haze (ASTM D1003) of less than 20%, a DuPont impact strength (23 캜, kg · cm) of N / B (Not Breakable), a DuPont impact strength kg · cm) is 60 to 150 g / 10 cm 2. (A) forming a first copolymer of 90 to 98% by weight of propylene, 1 to 5% by weight of ethylene and 1 to 5% by weight of 1-butene;
(B) a second copolymer of 60 to 85 wt.% Propylene, 10 to 35 wt.% Ethylene and 1 to 5 wt.% 1-butene in the presence of said first copolymer is blocked with said first copolymer Forming a block copolymer; And
(C) 80 to 98% by weight of the block copolymer, 2 to 10% by weight of a linear low density polyethylene resin having a melt index (190 占 폚, 2.16 kg) of 0.5 to 3.0 g / 10 min and a density of 0.91 to 0.93 g / ;
, ≪ / RTI &
The step of forming the block copolymer (B) is carried out at a molar ratio of [ethylene / (ethylene / propylene + 1-butene)] of 0.2 to 0.3 and a molar ratio of hydrogen / ethylene of 0.1 to 0.5. Propylene resin composition.