KR101984820B1 - Film for medical application with higher flexibility and transparency - Google Patents

Abstract

A medical multilayer film using a polypropylene resin having excellent transparency and high softness properties is disclosed. The present invention relates to an outer layer comprising homopolypropylene (A); 40 to 60% by weight of amorphous polypropylene (B) polymerized with a metallocene catalyst and 40 to 60% by weight of a mixture of propylene-ethylene-1-butene random copolymer and propylene-ethylene-1-butene elastomer (C) An intermediate layer comprising; And an inner layer comprising 5 to 25% by weight of the component (B) and 75 to 95% by weight of the component (C).

Description

TECHNICAL FIELD [0001] The present invention relates to a medical film having excellent softness and transparency,

TECHNICAL FIELD The present invention relates to a medical film, and more particularly, to a medical film excellent in softness and transparency.

Conventional medical films require high softness properties and transparency. Accordingly, many companies have developed and applied the product by mixing the styrene elastomer and the ethylene-based elastomer to improve the softness and transparency of the film. However, such elastomer products are somewhat less compatible with the polypropylene resin used, resulting in somewhat lower transparency and film uniformity during use of the product.

Korean Patent No. 1273049 relates to a medical multilayer film comprising three layers, a polypropylene and a propylene-alpha olefin copolymer, and an intermediate layer using a propylene / alpha olefin rubber copolymer. Although the structure of the technology has excellent transparency, there is a problem in that the film has insufficient impact resistance and transparency after sterilization at high temperature.

Korean Patent No. 1104197 relates to the production of a tube having a structure similar to that of a film used for medical use, and the elastomer used in the technique is ENGAGE, which is compatible with a polypropylene product used as an ethylene- The lowering of the transparency and the lowering of the uniformity of the physical property occur.

Korean Patent Laid-Open Publication No. 2015-0076208 discloses a medical tube and bag, which is made of a mixture of polypropylene, a styrene elastomer and an olefin elastomer, and has a high softness characteristic, but has a very low transparency and impact resistance, Improvement of physical properties is necessary.

The present invention aims to provide a medical multilayer film using a polypropylene resin having excellent transparency and high softness characteristics.

In order to solve the above-mentioned problems, the present invention provides a laminate comprising: an outer layer comprising homopolypropylene (A); 40 to 60% by weight of amorphous polypropylene (B) polymerized with a metallocene catalyst and 40 to 60% by weight of a mixture of propylene-ethylene-1-butene random copolymer and propylene-ethylene-1-butene elastomer (C) An intermediate layer comprising; And an inner layer comprising 5 to 25% by weight of the component (B) and 75 to 95% by weight of the component (C).

Characterized in that the homopolypropylene is polymerized using a Ziegler Natta catalyst and has a melting temperature of 167 DEG C or higher, a crystallinity of 55% or higher, and a melt index (230 DEG C, 2.16 kg load) of 2 to 10 g / 10 min A medical film is provided.

And the amorphous polypropylene is polymerized under a catalyst containing a transition metal compound represented by the following formula (1).

[Chemical Formula 1]

(C ₁ -C ₂₀ ) alkyl, (C ₂ -C ₂₀ ) alkenyl, (C ₂ -C ₂₀ ) alkenyl, and (C ₂ -C ₂₀ ) alkynyl, wherein M is a transition metal of Group 4, Q ¹ and Q ² are each independently selected from the group consisting of halogen, 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₎ alkyl amido; (C ₆ -C ₂₀₎ aryl amido; or (C ₁ -C ₂₀₎ alkylidene and;

R ¹ to R ¹⁰ are each independently hydrogen; (C ₁ -C ₂₀ ) alkyl, with or without an acetal, ketal, ether group; Acetals, ketals, which does not contain a group containing an ether or (C ₂ -C ₂₀₎ alkenyl; (C ₁ -C ₂₀ ) alkyl (C ₆ -C ₂₀ ) aryl, with or without an acetal, ketal, ether group; (C ₆ -C ₂₀ ) aryl (C ₁ -C ₂₀ ) alkyl, with or without an acetal, ketal, ether group; Or (C ₁ -C ₂₀ ) silyl with or without an acetal, ketal, ether group; R ¹ may be linked to R ² to form a ring, and R ⁶ to R ¹⁰ More than 2 out of They may be connected to each other to form a ring;

R ³ and R ⁴ are each independently hydrogen or methyl, provided that at least one of R ³ and R ⁴ is methyl;

R ⁵ is (C ₁ -C ₂₀ ) alkyl, with or without an acetal, ketal, ether group;

R ¹¹ , R ¹² and R ¹³ are each independently hydrogen; (C ₁ -C ₂₀ ) alkyl, with or without an acetal, ketal, ether group; Acetals, ketals, which does not contain a group containing an ether or (C ₂ -C ₂₀₎ alkenyl; (C ₁ -C ₂₀ ) alkyl (C ₆ -C ₂₀ ) aryl, with or without an acetal, ketal, ether group; (C ₆ -C ₂₀ ) aryl (C ₁ -C ₂₀ ) alkyl, with or without an acetal, ketal, ether group; (C ₁ -C ₂₀ ) silyl with or without an acetal, ketal, ether group; (C ₁ -C ₂₀₎ alkoxy; Or (C ₆ -C ₂₀₎ aryloxy, and; R ¹¹ and R ¹² Or R ¹² and R ¹³ may be connected to each other to form a ring.

The amorphous polypropylene has a weight average molecular weight of 200,000 to 300,000 g / mol, a density of 0.8 to 0.9 g / ml, and a degree of stereochemistry (isotacticity, Pentad II, mmmm) of 5 to 20% A medical film is provided.

And the mixture further comprises a medical film characterized in that the random copolymer and the elastomer are produced in the same polymerization reactor.

And the outer layer comprises 0.1 to 10% by weight of the component (B).

In order to improve the transparency of the conventional medical film, there is a problem that the compatibility with the product of polypropylene is lowered by using an elastomer product of other ethylene and styrene type components, and transparency and softness after sterilization are reduced. However, A soft film made of the same material as the polypropylene and a three-way random copolymer elastomer to maximize compatibility, thereby providing a medical film having excellent impact strength and heat bonding performance while maintaining transparency and softness.

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 invention relates to an outer layer comprising homopolypropylene (A); 40 to 60% by weight of amorphous polypropylene (B) polymerized with a metallocene catalyst and 40 to 60% by weight of a mixture of propylene-ethylene-1-butene random copolymer and propylene-ethylene-1-butene elastomer (C) An intermediate layer comprising; And an inner layer comprising 5 to 25% by weight of the component (B) and 75 to 95% by weight of the component (C).

In the present invention, the homopolypropylene constituting the outer layer is polymerized by utilizing a Ziegler-Natta catalyst. It is preferable that a low active site is removed during the production of the catalyst and phthalate-based materials are not used as an electron donor. It is preferable that the film has a high stereoregularity and a high heat resistance so that the melting temperature is preferably 167 DEG C or higher and the film surface is uniform when thermally bonded due to its high strength and heat resistance. The homopolypropylene preferably has a crystallinity of 55% or more and a melt index (230 DEG C, 2.16 kg load) of 2 to 10 g / 10 min.

The outer layer may contain, in addition to homopolypropylene, 0.1 to 10% by weight of an amorphous polypropylene polymerized with a metallocene catalyst, and a detailed description thereof will be given later.

In the present invention, the intermediate layer comprises 40 to 60% by weight of amorphous polypropylene (B) polymerized with a metallocene catalyst and 40 to 60% by weight of a mixture 40 of propylene-ethylene-1-butene random copolymer and propylene- To 60% by weight.

In the present invention, the amorphous polypropylene can be polymerized under a catalyst containing a specific transition metal compound described below at a glass transition temperature of -20 캜 or lower, which is much lower than that of the crystalline polypropylene.

Namely, the amorphous polypropylene (B) polymerized with the metallocene catalyst can be produced by referring to the patent application No. 2011-0033626 filed by the present applicant. That is, in the present invention, the amorphous polypropylene may be a polymer obtained by polymerization under a catalyst containing a transition metal compound represented by the following general formula (1).

[Chemical 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 to R ¹⁰ are each independently hydrogen; (C ₁ -C ₂₀ ) alkyl, with or without an acetal, ketal, ether group; Acetals, ketals, which does not contain a group containing an ether or (C ₂ -C ₂₀₎ alkenyl; (C ₁ -C ₂₀ ) alkyl (C ₆ -C ₂₀ ) aryl, with or without an acetal, ketal, ether group; (C ₆ -C ₂₀ ) aryl (C ₁ -C ₂₀ ) alkyl, with or without an acetal, ketal, ether group; Or (C ₁ -C ₂₀ ) silyl with or without an acetal, ketal, ether group; R ¹ may be linked to R ² to form a ring, and R ⁶ to R ¹⁰ More than 2 out of They may be connected to each other to form a ring;

R ³ and R ⁴ are each independently hydrogen or methyl, provided that at least one of R ³ and R ⁴ is methyl;

R ⁵ is (C ₁ -C ₂₀ ) alkyl, with or without an acetal, ketal, ether group;

R ¹¹ , R ¹² and R ¹³ are each independently hydrogen; (C ₁ -C ₂₀ ) alkyl, with or without an acetal, ketal, ether group; Acetals, ketals, which does not contain a group containing an ether or (C ₂ -C ₂₀₎ alkenyl; (C ₁ -C ₂₀ ) alkyl (C ₆ -C ₂₀ ) aryl, with or without an acetal, ketal, ether group; (C ₆ -C ₂₀ ) aryl (C ₁ -C ₂₀ ) alkyl, with or without an acetal, ketal, ether group; (C ₁ -C ₂₀ ) silyl with or without an acetal, ketal, ether group; (C ₁ -C ₂₀₎ alkoxy; Or (C ₆ -C ₂₀₎ aryloxy, and; R ¹¹ and R ¹² Or R ¹² and R ¹³ may be connected to each other to form a ring.

At this time, the transition metal compound of the formula (1) is activated by the cocatalyst compound to give an activity to the polymerization reaction of propylene. As the cocatalyst compound, the transition metal compound of the formula (1) Any compound capable of activating a metal compound can be used without limitation. As such a promoter compound, for example, compounds represented by the following formulas (2) to (4) can be used.

(2)

In formula (2), R ³¹ is independently a (C 1 -C 20) hydrocarbyl radical substituted with a halogen radical, a (C 1 -C 20) hydrocarbyl radical or a halogen; a is an integer of 2 or more.

(3)

In Formula 3, D is aluminum or boron; R ³¹ is independently a (C 1 -C 20) hydrocarbyl radical substituted with a halogen radical, a (C 1 -C 20) hydrocarbyl radical or a halogen.

[Chemical Formula 4]

In Formula 4, L is a neutral or cationic Lewis acid; Z is a Group 13 element; A is independently (C6-C20) aryl or (C1-C20) alkyl wherein at least one hydrogen atom is replaced by halogen, (C1-C20) hydrocarbyl, (C1-C20) alkoxy or Alkyl radical.

In the present invention, the preparation of the amorphous polypropylene can be carried out by polymerizing propylene in the presence of the catalyst compound, which may be carried out in slurry, liquid, vapor or bulk according to known methods, Semi-continuous or continuous reaction, and a specific manufacturing method can be referred to Patent Application No. 2011-0033626 filed by the present applicant.

The amorphous polypropylene preferably has a weight average molecular weight of 200,000 to 300,000 and a degree of stereochemistry (isotacticity, pentad II, mmmm) of 5 to 20%. The density of the amorphous polypropylene is preferably 0.8 to 0.9 g / ml, more preferably 0.82 to 0.9 g / ml, and most preferably 0.82 to 0.89 g / ml. If the weight average molecular weight is less than 200,000, the use may be limited because the resin is sticky at room temperature. If the weight average molecular weight is more than 300,000, the flowability of the resin may be deteriorated and the moldability may be poor.

As the amorphous polypropylene, a propylene homopolymer may be used, but not limited thereto, a copolymer of ethylene and at least one monomer selected from alpha-olefins having 4 to 10 carbon atoms may be used. At this time, the content of the monomer is preferably 5 to 30% by weight, more preferably 15 to 25% by weight.

Unlike the conventional ternary copolymer, the mixture of the propylene-ethylene-1-butene random copolymer and the propylene-ethylene-1-butene elastomer (C) -Ethylene-1-butene terpolymer and an elastomer of the same component as the ethylene-1-butene terpolymer. That is, the elastomer produced in a single process is propylene-ethylene-1-butene, which is an amorphous resin having almost the same components but little crystallinity.

The propylene-ethylene-1-butene random copolymer is produced in a polymerization reactor using propylene, ethylene and 1-butene as raw materials and is introduced into a mixer. The propylene-ethylene-1-butene random copolymer may contain 1 to 10 mol% of ethylene and 1-butene, respectively, and the remaining 80 to 98 mol% of propylene. The melting temperature by DSC is preferably 135 占 폚 or lower, and the melt index is preferably 3 to 10 g / 10 min (230 占 폚, 2.16 kg).

Such a propylene-ethylene-1-butene random copolymer imparts excellent optical and thermodynamic compatibility with the elastomer component described later while maintaining the transparency of the polypropylene resin composition.

The elastomer is a propylene-ethylene-1-butene elastomer having the same composition as that of the propylene-ethylene-1-butene random copolymer, and the propylene-ethylene-1-butene random copolymer Are prepared in the same polymerization reactor using the same raw materials as those used in the first polymerization reactor and then introduced into a mixer.

That is, in the conventional extrusion process using a crystalline propylene-ethylene-1-butene random copolymer, an elastomer product which is separately prepared with a composition different from that of the crystalline propylene-ethylene-1-butene random copolymer component is mixed with the extruder However, in the present invention, an elastomer is prepared and mixed with the propylene, ethylene, and 1-butene raw materials fed in the same line by using the same reactor and by adjusting the content thereof, reaction conditions, -Butene random copolymer is maximized and high transparency and softness characteristics can be imparted.

The propylene-ethylene-1-butene elastomer is an amorphous polypropylene resin composition having no crystallinity. The amorphous polypropylene resin composition has a melting temperature of 100 占 폚 or less and a softening point temperature of 80 占 폚 or less. The propylene component has 5 to 30% 30 mol%, and a melt index (230 DEG C, 2.16 kg load) of 2 to 10 g / 10 min.

If the content of ethylene or 1-butene is less than 5 mol%, the softness of the elastomer may be deteriorated. If the content of ethylene or 1-butene is more than 30 mol%, transparency may be decreased and sticking blocking due to low molecular weight may be caused. If the melt index is less than 2 g / 10 min, the extrusion amount may be lowered, and if it exceeds 10 g / 10 min, the bubble may be shaken. If the melting temperature is higher than 100 ° C, the degree of crystallization of the copolymer may become unnecessarily high, resulting in a problem of increasing the softness of the resulting composition. Further, even when the softening point temperature exceeds 80 캜, a problem of increasing the softness may occur.

On the other hand, the propylene-ethylene-1-butene elastomer is preferably produced using a metallocene catalyst, and has a molecular weight distribution narrower than that copolymerized with a Ziegler-Natta catalyst, so that blocking due to adhesion of a low molecular weight polymer is small , A low melting temperature and a low surface hardness can be obtained.

In the present invention, the propylene-ethylene-1-butene elastomer is preferably contained in an amount of 10 to 25% by weight in the mixture (C). If the content of propylene-ethylene-1-butene elastomer is less than 10% by weight, transparency is good but softness may be deteriorated. If it is more than 25% by weight, softness and crystallinity may be deteriorated.

The content ratio of the amorphous polypropylene (B) and the mixture (C) constituting the intermediate layer is preferably 40 to 60% by weight in view of transparency and softness of the film.

Meanwhile, in the present invention, the inner layer contains the amorphous polypropylene (B) and the mixture (C), but the content ratio thereof is somewhat different from that of the intermediate layer. That is, the inner layer preferably contains 5 to 25% by weight of the amorphous polypropylene (B) and 75 to 95% by weight of the mixture (C).

In addition, the resin composition constituting each layer of the multilayer film according to the present invention may contain slip agent and other additives in an amount of 1% by weight or less for processing the film in addition to the component. In order to prevent adhesion between the films, Mineral ingredients may be included.

Hereinafter, a specific embodiment of the present invention will be described.

Example 1

(Melting point: 169 DEG C, crystallinity: 58% and melt index (230 DEG C, load of 2.16 kg) 10 g / 10 min) as the component (A), and amorphous polypropylene (Mw / Mn) 5 and II (%, mmmm) of 20%, a density (Mw / Mn) of 3 g / 10 min (230 deg. C under a load of 2.16 kg), a weight average molecular weight (measured by GPC method, PL-GPC220, Agilent) (A) component alone, the intermediate layer (B) was used as the component (C), and the mixture (melt index (230 ° C, 2.16 kg load) Layered film was formed using a multilayer film forming machine (line speed 5 m / min) composed of 50% by weight of each of the components (A) and (C) and 90% by weight of the component (C) and 10% .

[Production method of amorphous polypropylene]

Patent Application No. 2011-0033626. The interior of the high-pressure reactor (internal volume: 2 L, stainless steel) was replaced with nitrogen at room temperature. About 4.0 ml of a toluene solution of methylaluminoxane (10 wt% solution of methylaluminoxane in toluene, 6 mmol of Al, manufactured by Albemarle) was added to the reactor, and then 500 g of propylene was added and the temperature was raised to 70 캜. Subsequently, a solution (1.5 ml, 3.0 μmol of Ti) in which toluene was dissolved in the transition metal compound represented by the following formula (2) was injected into the reactor and polymerization was carried out. After the polymerization reaction was carried out, the temperature was lowered to room temperature, excess propylene was removed, and the polymer was recovered. The resulting polymer was dried in a vacuum oven at 80 DEG C for 4 hours or more to obtain polypropylene.

(2)

[Process for Preparing Propylene-Ethylene-1-Butene Ternary Copolymer and Elastomer Mixture]

(Ethylene content: 5 mol%, 1-butene content: 3.5 mol%, melt index (230 DEG C, 5 DEG C), and the like) prepared by using a propylene, ethylene and 1-butene raw material through a polymerization reactor. (Ethylene content: 10 mol%, 1-butene content: 10 mol%, melt index: 230 (mol%), and the like), 80 parts by weight of a propylene- , 0.5 g of an amide type slipping agent and 0.5 weight part of a porous silica blocking agent were charged into a Henschel mixer, and the Henschel mixer was operated under conditions of 500 rpm for 1 minute and 1,500 rpm for 0.5 minutes. Min, and the mixture was further mixed at 500 rpm to discharge the sample out. The mixture was thoroughly mixed for 3 to 5 minutes, and then the mixture was extruded through a 40 mm single screw extruder having a L / D of 35 to 180 ° C. Resin mixture was prepared.

Example  2

(C) a homopolypropylene having a melt index of 2 g / 10 min as the component (A) in Example 1 and a non-crystalline polypropylene having a weight average molecular weight of 200,000 and an II of 5% as the component (B) (A) and 10% by weight of the component (B), the intermediate layer contained 50% by weight each of the components (B) and (C), and the inner layer had a melt index of 10 g / 10 min. Layered film was formed in the same manner as in Example 1 except that the component (B) was composed of 80 wt% of component (C) and 20 wt% of component (B).

Example  3

(C) a homopolypropylene having a melt index of 4 g / 10 min as the component (A) in Example 1 was used, and amorphous polypropylene having a weight average molecular weight of 300,000 and 15% of II was used as the component (B) (A) and 5% by weight of the component (B), and 50% by weight of the components (B) and (C) Layered film was formed in the same manner as in Example 1 except that the component (C) was composed of 85% by weight of the component (C) and 15% by weight of the component (B)

Example  4

(C) a homopolypropylene having a melt index of 1 g / 10 min as the component (A) in Example 1 and a non-crystalline polypropylene having a weight average molecular weight of 270,000 and an II of 15% as the component (B) (A) and 15% by weight of the component (B), and the intermediate layer contained 50% by weight each of the components (B) and (C) Layered film was formed in the same manner as in Example 1 except that the component (C) was composed of 85% by weight of the component (C) and 15% by weight of the component (B)

Comparative Example  One

(C) a homopolypropylene having a melt index of 3 g / 10 min as the component (A) in Example 1, a non-crystalline polypropylene having a weight average molecular weight of 300,000 and an II of 35% as the component (B) (A) and 5% by weight of the component (B), and the intermediate layer (B) and the propylene-ethylene-1-butene random random copolymer (melt index: 5.5 g / 10 min) Layered film was formed in the same manner as in Example 1, except that the inner layer was composed of the component (C) in an amount of 50% by weight and the inner layer in the inner layer was composed of 85% by weight of the component (C) and 15% by weight of the component (B).

Comparative Example  2

(B), a styrene elastomer (melt index: 1 g / 10 min) was used as the component (A) in Example 1, a homopolypropylene having a melt index of 11 g / (B) and (C) were used in an amount of 95 wt% and 5 wt%, respectively. The intermediate layer contained 50 wt% of each of the components (B) and (C) , 75 wt% of the component (B) and 25 wt% of the component (B) were molded in the same manner as in Example 1.

Experimental Example

The properties of the multilayered film formed according to the above Examples and Comparative Examples were measured and evaluated by the following methods, and the results are shown in Table 1 below. Evaluation criteria of the respective properties are shown in Table 2 below.

[Measurement and evaluation of physical properties]

1) Surface Appearance: Wrinkle and Thickness Uniformity of Film Outer Appearance The state of the wrinkle and the thickness uniformity of the outer appearance of the film was visually checked and evaluated as very good (?), Good (?) And poor (X).

2) Film Blocking: After sterilization with a load of 500 g to 1000 g, the adhesion strength between the films (the strength when the film fell) was measured.

3) Haze (ASTM D1003): The degree of fogging of the sterilized film was measured.

4) Film Impact Strength (ASTM D1709): A ball was dropped at a height of 60 cm to measure its weight.

5) Thermal Adhesion: The occurrence of defects due to peeling of the thermal bonding region after thermal bonding (TEST condition: 2KG / 1 second) between the films was examined.

Referring to Table 1, each layer was made of a flexible material of the same material as that of the polypropylene and a three-way random copolymer elastomer to be a matrix according to the present invention, and particularly, homopolypropylene, amorphous polypropylene and propylene - When a mixture of ethylene-1-butene terpolymer and elastomer is used (Examples 1 to 3), transparency and softness are maximized due to maximization of compatibility, and a medical film having excellent impact strength and heat bonding performance can be realized Can be confirmed.

On the other hand, when a mixture of an amorphous polypropylene or a propylene-ethylene-1-butene terpolymer and an elastomer was replaced with a conventional component (Comparative Examples 1 and 2), two or more of appearance, transparency, impact strength, It can be seen that the physical properties are remarkably lowered.

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 (6)

An outer layer comprising homopolypropylene (A);
40 to 60% by weight of amorphous polypropylene (B) polymerized with a metallocene catalyst and 40 to 60% by weight of a mixture of propylene-ethylene-1-butene random copolymer and propylene-ethylene-1-butene elastomer (C) An intermediate layer comprising; And
An inner layer comprising 5 to 25% by weight of the component (B) and 75 to 95% by weight of the component (C);
A medical film,
Wherein the homopolypropylene is polymerized using a Ziegler Natta catalyst and has a melting temperature of 167 DEG C or higher, a crystallinity of 55% or higher and a melt index (230 DEG C, 2.16 kg load) of 2 to 10 g /
Wherein the amorphous polypropylene is polymerized under a catalyst containing a transition metal compound represented by the following formula (1)
[Chemical Formula 1]

(C ₁ -C ₂₀ ) alkyl, (C ₂ -C ₂₀ ) alkenyl, (C ₂ -C ₂₀ ) alkenyl, and (C ₂ -C ₂₀ ) alkynyl, wherein M is a transition metal of Group 4, Q ¹ and Q ² are each independently selected from the group consisting of halogen, 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₎ alkyl amido; (C ₆ -C ₂₀₎ aryl amido; or (C ₁ -C ₂₀₎ alkylidene and;
R ¹ to R ¹⁰ are each independently hydrogen; (C ₁ -C ₂₀ ) alkyl, with or without an acetal, ketal, ether group; Acetals, ketals, which does not contain a group containing an ether or (C ₂ -C ₂₀₎ alkenyl; (C ₁ -C ₂₀ ) alkyl (C ₆ -C ₂₀ ) aryl, with or without an acetal, ketal, ether group; (C ₆ -C ₂₀ ) aryl (C ₁ -C ₂₀ ) alkyl, with or without an acetal, ketal, ether group; Or (C ₁ -C ₂₀ ) silyl with or without an acetal, ketal, ether group; R ¹ may be linked to R ² to form a ring, and at least two of R ⁶ to R ¹⁰ They may be connected to each other to form a ring;
R ³ and R ⁴ are each independently hydrogen or methyl, provided that at least one of R ³ and R ⁴ is methyl;
R ⁵ is (C ₁ -C ₂₀ ) alkyl, with or without an acetal, ketal, ether group;
R ¹¹ , R ¹² and R ¹³ are each independently hydrogen; (C ₁ -C ₂₀ ) alkyl, with or without an acetal, ketal, ether group; Acetals, ketals, which does not contain a group containing an ether or (C ₂ -C ₂₀₎ alkenyl; (C ₁ -C ₂₀ ) alkyl (C ₆ -C ₂₀ ) aryl, with or without an acetal, ketal, ether group; (C ₆ -C ₂₀ ) aryl (C ₁ -C ₂₀ ) alkyl, with or without an acetal, ketal, ether group; (C ₁ -C ₂₀ ) silyl with or without an acetal, ketal, ether group; (C ₁ -C ₂₀₎ alkoxy; Or (C ₆ -C ₂₀₎ aryloxy, and; R ¹¹ and R ¹² or R ¹² and R ¹³ may be connected to each other to form a ring.)
The amorphous polypropylene has a weight average molecular weight of 200,000 to 300,000 g / mol, a density of 0.8 to 0.9 g / ml, a degree of stereochemistry (isotacticity, pentad II, mmmm) of 5 to 20%
Wherein the medical film has a blocking property evaluated by an adhesive strength between the outer layer, the intermediate layer and the inner layer measured after sterilization with a load of 500 g to 1000 g is less than 50 gf, a haze according to ASTM D1003 is less than 5%, a film according to ASTM D1709 A peel strength of not less than 700 gf / cm < 2 >, wherein an impact strength is not less than 500 g and peeling of the heat-bondable portion occurs after thermal bonding between the films under the condition of 2 KG / 1 second. delete delete delete The method according to claim 1,
Characterized in that the mixture is prepared in the same polymerization reactor in which the random copolymer and the elastomer are in the same polymerization reactor. The method according to claim 1,
Wherein the outer layer comprises 0.1 to 10% by weight of the component (B).