JPH08231787A - Polymer composition for medical bag and bag for medical use - Google Patents

Abstract

PURPOSE: To provide a polymer composition for a medical bag having excellent flexibility, transparency, impact resistance and heat resistance, and to provide a bag for medical use made of the same polymer. CONSTITUTION: A polymer composition for a medical bag characteristically composed of 70-90wt.% a component (A) and 30-10wt.% a component (B), and a bag for medical use obtained by blow molding the polymer composition. The component (A) is a propylene-α-olefin random copolymer containing 2.5-8wt.% α-olefin other than propylene and has 0.1-20g/10min melt flow rate. The component (B) is an ethylenic polymer comprising component (B1) and component (B2) shown below and a weight ratio ((B1):(B2)) is (90:10)-(10:90). Component (B1): an ethylene-propylene copolymer containing 60-90wt.% ethylene and having 1-20g/10min melt flow rate at 230 deg.C, and component (B2): an ethylene-butene-1 copolymer containing 65-95wt.% ethylene and having 1-50g/10min melt flow rate at 230 deg.C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polymer composition which gives a molded article excellent in flexibility, transparency, impact resistance and heat resistance, and a chemical solution obtained by blow molding the polymer composition. It relates to a medical bag that holds blood, blood, etc.

[0002]

2. Description of the Related Art Containers for medical use such as electrolyte preparations, medicinal solutions such as nutritional infusions, blood, etc., are hard type plastics centered on polypropylene from the viewpoint of handling (lightening) and impact resistance instead of conventional glass bottles. It is changing to a bottle made from plastic, and from the viewpoint of preventing infection in hospitals, it changes to a soft type plastic bag that is excellent in preventing bacteria from being squeezed by atmospheric pressure as the bag itself is squeezed by atmospheric pressure without the need for an air needle. It's starting.

Currently, low-density polyethylene, linear low-density polyethylene, ethylene-vinyl acetate copolymer, soft polyvinyl chloride and the like are used as materials for medical bags, but they have low heat resistance during high-pressure steam sterilization. Is a problem. As a method for improving heat resistance, a method has been proposed in which a bag is made into a laminate (Japanese Patent Laid-Open No. 62-44256), or the inner surface of the bag is made to project (Japanese Patent Laid-Open No. 60-246757). Is also troublesome in processing. Further, soft polyvinyl chloride has problems of hygiene and generation of toxic gas due to the plasticizer and polymer structure.

As the material for the bag, a propylene-based material is preferable from the viewpoint of heat resistance, and conventionally, the following flexible containers have been proposed as the propylene-based container. There is a problem in flexibility that the bag itself does not need a needle and the content of the bag itself is squeezed out by the atmospheric pressure when the contents are dropped. That is, JP-A-63-281945 discloses that propylene having an α-olefin content other than propylene of 2.5 to 8% by weight, a melt flow rate (230 ° C.) of 0.01 to 30 g / 10 minutes and a melt tension of 0.1 to 100 g. -An infusion bottle consisting of an α-olefin random copolymer, and in JP-A-2-208339, polypropylene and ethylene-
A single-layer or multi-layer highly transparent hollow molded article composed of three components of α-olefin copolymer rubber and propylene-α-olefin copolymer rubber, and in JP-A-4-202409, a block copolymer composed of propylene and ethylene. Flexible containers have been proposed, but these have a problem of flexibility enough to satisfy the self-draining property.

[0005]

DISCLOSURE OF THE INVENTION The present invention is directed to a polymer composition mainly composed of a propylene-based material from the viewpoint of heat resistance and having flexibility satisfying self-drainage property, and a polymer composition formed by molding the polymer composition. The purpose is to obtain a medical bag.

[0006]

[Means for Solving the Problems]

[Summary of the Invention] The present inventors have conducted intensive studies in view of the above problems, and as a result, a polymer composition in which a specific amount of an ethylene polymer of a specific type is mixed with a specific propylene random copolymer is obtained. In addition, a composition having a melt flow rate (230 ° C.) and a memory effect (190 ° C.) within a specific range is excellent in blow moldability, flexibility, transparency and impact resistance,
It has also been found that it has good heat resistance and is suitable as a material for medical solutions such as infusions and medical bags for blood. Furthermore, the one obtained by adding a specific nucleating agent to the polymer composition of the present invention has been a problem in the conventional addition and blending of the nucleating agent at a high temperature (1) in a plastic container test for infusion (Japanese Pharmacopoeia).
(21 ° C.) The present invention was completed by finding that there is no problem with the elution property and the heat resistance is further improved.

That is, in the first aspect of the present invention, as the component (A), propylene is a main component, and the content of at least one α-olefin selected from ethylene and carbon numbers 4 to 12 is 2.5 to 8% by weight. %, And 70 to 90% by weight of a propylene-α olefin random copolymer having a melt flow rate of 0.1 to 20 g / 10 minutes, the following (B1) component and (B2) component as the (B) component, and The weight ratio ((B1) :( B2)) is 90:10 to 10:90.
Is a polymer composition for medical bags comprising 30 to 10% by weight of the ethylene-based copolymer. Component (B1): ethylene content 60 to 90% by weight, melt flow rate (230 ° C.) 1 to 20 g / 10 min ethylene-propylene copolymer (B2) component; ethylene content 65 to 95% by weight, melt flow Rate (230 ° C.) 1 to 50 g / 10 min Ethylene-butene 1 copolymer Also, a second invention of the invention is a medical bag characterized by being obtained by blow molding of such a polymer composition. is there.

[Detailed Description of the Invention] (1) Constituent Component (A) Component: Propylene-α-olefin Copolymer The propylene-α-olefin random copolymer used in the present invention has a crystallinity of 20 by a density gradient method. ~ 70% crystalline resin. Propylene-α olefin block copolymers are not preferable in terms of transparency and flexibility. or,
The α-olefin as a comonomer is ethylene, butene, pentene, hexene or the like having 2 to 12 carbon atoms (excluding propylene).
Α olefin of the above, and one or more of these may be used. Among them, ethylene is preferable as the comonomer. The content of α-olefin is 2.5 to 8% by weight. If it is less than 2.5% by weight, the flexibility of the product obtained by the present invention will be impaired, while if it exceeds 8% by weight, the amount of low crystalline polymer will increase and the heat resistance will remarkably decrease.

The melt flow rate (JI
(Based on SK-7210; 230 ° C, 2.16 kg load)
Is 0.1 to 20 g / 10 minutes, preferably 0.5 to 10
g / 10 minutes, more preferably 1 to 5 g / 10 minutes.
If it is less than 0.1 g / 10 minutes, the appearance and transparency of the molded article obtained by the present invention will be poor, and if it exceeds 20 g / 10 minutes, drawdown will occur, resulting in poor blow moldability. Such a propylene-α-olefin random copolymer is generally produced in the presence or absence of an inert solvent using a Ziegler-type stereospecific polymerization catalyst by directly applying the production technique of a propylene-ethylene random copolymer. To be done. Further, those produced by a polymer production process that does not require a decatalysis step can also be applied.

Component (B): Ethylene Copolymer The component (B1) is composed of the following components (B1) and (B2) which are both amorphous and have the properties of an elastomer, and their weight ratio ((B1) : (B2)) is 90:10 to 10: 9
It is 0, preferably 80:20 to 20:80.
When the component (B1) exceeds 90 by weight, the flexibility and impact resistance are improved according to the amount added, but the transparency is remarkably deteriorated, and when the component (B2) exceeds 90 by weight, the transparency depending on the amount added is increased. Although the decrease is small, the effect of improving flexibility and impact resistance is small. It is important to use the following components (B1) and (B2) together.

Component (B1): ethylene-propylene copolymer The component (B1) has an ethylene content of 60 to 90% by weight, a melt flow rate (according to JIS K7210, 230 ° C.,
2.16 kg load) 1 to 20 g / 10 min ethylene-propylene copolymer. Component (B2): ethylene-butene 1 copolymer (B2) component has an ethylene content of 65 to 95% by weight, a melt flow rate (according to JIS K7210, 230 ° C.,
2.16 kg load) 1 to 50 g / 10 min of ethylene-butene 1 copolymer.

Nucleating Agent In the present invention, it is preferable to add a metal salt of aromatic phosphoric acid represented by the following general formula [I] as a nucleating agent.

[0013]

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(Wherein R ¹ and R ² are hydrogen atoms or alkyl groups having 1 to 18 carbon atoms, M is a Group Ia or Group IIa metal, n is an integer of 1 or 2 and X is Represents an alkylidene group.)

Among the metal salts of aromatic phosphoric acid represented by the above general formula [1], preferred is a = 1, that is, a Group Ia metal, and a specific example thereof is 2,2'-methylene- Bis (4,6-di-t-butylphenyl) phosphoric acid sodium salt and lithium salt, 2,2'-ethylidene-bis (4,6-di-t-butylphenyl) phosphoric acid sodium salt and lithium salt 2,2'-methylidene-bis (4,6-di-t-butylphenyl) phosphoric acid potassium salt and the like. Among these, 2,2'-
Methylene-bis (4,6-di-t-butylphenyl) sodium phosphate, 2,2'-methylene-bis (4,6-
Lithium di-t-butylphenyl) phosphate is preferred,
In particular, sodium 2,2′-methylene-bis (4,6-di-t-butylphenyl) phosphate is most preferable from the viewpoints of elution property, rigidity and transparency of the composition. The addition amount is 0.001 to 0.5 part by weight, preferably 0.0015 to 0.3 part by weight, based on 100 parts by weight of the polymer composition. If it is less than this range, the nucleating effect (improvement in heat resistance) is small, and if it exceeds this range, it is uneconomical and the impact strength of the molded product may be lowered. High temperature (121 ℃) in infusion plastic container test
Heat resistance is improved without any problems in elution. Therefore, a medical bag particularly suitable for infusion can be manufactured.

Other Components The polymer composition used in the present invention may contain other additional components as long as the effects of the present invention are not significantly impaired. For example, antioxidants, light stabilizers, neutralizing agents, and other metal deactivators, antistatic agents, lubricants, organic / inorganic pigments, fillers, peroxides, other nucleating agents, if necessary.
Further, low-density polyethylene, linear low-density polyethylene, ethylene / vinyl acetate copolymer, etc. can be added within a range that does not impair the effects of the invention.

(2) Polymer Composition Physical Properties of Polymer Composition The melt flow rate (according to JIS K7210, 230 ° C., 2.16 kg load) of the composition is preferably 0.1.
~ 13g / 10 minutes, more preferably 0.5-7g
/ 10 minutes, particularly preferably 1 to 5 g / 10 minutes. If it is less than 0.1 g / 10 min, the transparency and surface appearance of the obtained molded product will be poor, while if it exceeds 13 g / 10 min, blow moldability (drawdown of parison, etc.) will be poor.

The memory effect (190 ° C.) is 1.5 to 2.5, preferably 1.7 to 2.3. If it is less than 1.5, the drawdown in the blow bag molding becomes poor, and if it exceeds 2.5, the burr biting in the blow bag molding becomes poor. Memory effect (balus effect) is a melt indexer or melt tension tester at a temperature of 190 ℃,
It is measured as the ratio of the diameter of the extrudate to the nozzle diameter when an extrusion rate of 0.1 g / min is obtained with an orifice having a diameter of 1.0 mmφ and a length of 8.0 mm.

Blending Ratio of Polymer Composition The blending ratio of the component (A) and the component (B) in the present invention is
The component (A) is 70 to 90% by weight, and the component (B) is 3
0 to 10% by weight, preferably (A) component 72
-88% by weight, and the component (B) is 28-12% by weight.
When the content of component (A) is less than 70% by weight, transparency and heat resistance become problems, and when it exceeds 90% by weight, flexibility and impact resistance become problems.

Production Method of Polymer Composition The polymer composition of the present invention can be produced by a usual production method. For example, the powder of the propylene-α-olefin random copolymer as the component (A) is added to the ethylene-propylene copolymer as the component (B1) and the ethylene-butene 1 copolymer as the component (B2), and the above-mentioned general Aromatic phosphoric acid metal salt represented by the formula (I), an antioxidant, and other components are added, and the mixture is stirred and mixed by a Henschel mixer, and then melt-kneaded and extruded by an extruder to form pellets. And The melt-kneading can be performed by a commonly used mixer such as a single-screw extruder, a twin-screw extruder, a Banbury mixer, a roll or a kneader.

(3) Method for producing medical bag A medical bag is produced by molding the above polymer composition, and a blow molding method is particularly preferable. Blow molding is performed by a usual method, and the molding conditions at that time are appropriately set. The medical bag of the present invention will be described below with reference to the drawings. 1 is a front view of the medical bag, FIG. 2 is a side view thereof, and the medical bag 1 is hollow. The medical bag 1 is basically composed of a body portion 2, a mouth portion 3, and a bottom portion 4, and a hanging piece 5 is connected to the bottom portion 4. These can be integrally manufactured by blow molding.

[0022]

EXAMPLES The present invention will be described more specifically by showing Examples and Comparative Examples (Examples 1 to 10 and Comparative Examples 1 to 9) below. The raw materials and the evaluation method used here are as described below. (1) Raw materials used (A) Component A-1: Ethylene content 2.0% by weight, crystallinity 63
%, Density 0.902, melt flow rate 1.5 g /
10 minutes propylene-ethylene random copolymer A-2: ethylene content 2.9% by weight, crystallinity 61
%, Density 0.900, melt flow rate 1.3 g /
10 minutes propylene-ethylene random copolymer A-3: ethylene content 5.1% by weight, crystallinity 57
%, Density 0.897, melt flow rate 2.3 g /
10 minutes propylene-ethylene random copolymer A-4: ethylene content 7.0% by weight, crystallinity 54
%, Density 0.894, melt flow rate 2.2 g /
10 minutes propylene-ethylene random copolymer A-5: ethylene content 8.6% by weight, crystallinity 51
%, Density 0.891, melt flow rate 2.1 g /
10 minutes propylene-ethylene random copolymer A-6: ethylene content 5.3% by weight, crystallinity 56
%, Density 0.896, melt flow rate 0.02 g
/ 10 minutes propylene-ethylene random copolymer A-7: ethylene content 5.1 wt%, crystallinity 57
%, Density 0.897, melt flow rate 25 g / 1
Propylene-ethylene random copolymer with 0 minutes The crystallinity is based on the density gradient method.

Component (B1) B1-1: Amorphous ethylene-propylene copolymer having an ethylene content of 78% by weight and a melt flow rate of 3.6 g / 10 min B1-2: Ethylene content of 73% by weight, melt Amorphous ethylene-propylene copolymer with a flow rate of 0.7 g / 10 min

Component (B2) B2-1: ethylene-butene 1 copolymer having ethylene content of 85% by weight and melt flow rate of 6.7 g / 10 minutes (nucleating agent) nucleating agent-1: phosphoric acid 2,2'-methylenebis (4,6-
Di-t-butylphenyl) sodium Nucleating agent-2: 1,3,2,4-di- (p-methylbenzylidene) sorbitol

(2) Preparation of polymer composition Tetrakis [methylene-3] relative to 100 parts by weight of the components A, B1 and B2 in the proportions shown in Table 1.
-(3 ', 5'-di-t-butyl-4-hydroxyphenyl) propionate] methane (antioxidant) 0.05
1 part by weight and 0.03 part by weight of calcium stearate (neutralizing agent) are charged into a Henschel mixer and mixed by stirring, and then a single screw extruder (Thermo Plastics Industry Co., Ltd.)
2 with a 50 mmφ extruder (vent type, L / D = 28)
The mixture was melt-kneaded at 20 ° C., extruded in a strand form from a die, and cut into pellets.

In Examples 8 and 9, 2,2'-methylenebis (4,6-di-t-butylphenyl) sodium phosphate (nucleating agent-1) was further added as the component (A), (B1) component and (B2) component total 1
0.002 parts by weight and 0.2 parts by weight were added to 00 parts by weight. Further, in Example 10, 1,3,2,4-di-
(P-Methylbenzylidene) sorbitol (Nucleating agent-
0.2 parts by weight was added to 100 parts by weight of the total of the components (A), (B1) and (B2).

(3) Manufacture of medical bag The pellets obtained in this way are screwed with a screw diameter of 50 m.
m blow molding machine (die opening is oval, Japan Steel Works JB105 type hollow molding machine), molding temperature 180
A blow molded bag (capacity 250 cc) having a wall thickness of the body portion 2 shown in the accompanying drawings of about 0.3 mm was molded at 0 ° C.

(4) Evaluation Melt flow rate (MFR): Measured in accordance with JIS K7210 under the conditions of 230 ° C. and 2.16 kg (unit: g / 1
0 minutes). Memory effect (ME): Diameter of 1.0 mmφ, length of 8. at a temperature of 190 ° C. using a melt indexer.
It was measured as the ratio of the diameter of the extrudate to the diameter of the nozzle when an extrusion rate of 0.1 g / min was obtained with an orifice of 0 mm. Blow moldability: The moldability under the blow molding conditions was observed. ◯: There was no problem in moldability. ×: A bag product having a uniform wall thickness could not be obtained due to a problem in moldability (drawdown). Self-draining property: An injection needle was inserted into a blow-molded bag in which the amount of water (water) and the amount of air were adjusted, and the drainage property was determined as follows. The height of the liquid head was about 75 cm, and a commercially available rubber stopper was cut into thin pieces at the mouth. The infusion set such as a tube that connects to the medical bag is "Infusion set 200 type" made by Nippon Medical Supply (without stopper rubber, V clamp fully open)
use. ○: Can be drained without resistance. X: The resistance is large during drainage, and there is residual liquid. Transparency: The haze of the blow-molded bag body was measured according to JIS K-6714. ◯: Haze ≦ 30% ×: Haze> 30% Heat resistance −1: In a steam pressure vessel set at 115 ° C.,
A blow-molded bag in which the amount of liquid (water) and the amount of air were adjusted was sandwiched between punching plates, and the bag was placed for 1 hour to observe the shape-retaining condition and evaluated as follows. ◯: The bag shape is retained without being deformed. X: Deformed. (Wrinkles, bending, traces of support plate, etc.) Heat resistance-2: In a steam pressure vessel set at 121 ° C,
A blow-molded bag in which the amount of liquid (water) and the amount of air were adjusted was sandwiched between punching plates, and the bag was placed for 1 hour to observe the shape-retaining condition and evaluated as follows. ◯: The bag shape is retained without being deformed. X: Deformed. (Wrinkles, bends, traces of support plate, etc.) Impact resistance: Blow-molded bag with adjusted liquid amount (water) and air amount is left standing in a low temperature tank at 4 ° C for 20 hours and then taken out immediately for 1.5 m. Drop from height. The same sample is horizontally dropped 5 times in succession and then 2 times vertically. ○: Do not break the bag. X: The bag was broken. Dissolution: Dissolution test of test strips (potassium permanganate reducing substance after dissolution for 1 hour at 121 ° C.) was carried out by the method for testing plastic containers for infusion (Japanese Pharmacopoeia). ○: Within the reference value (within 0.1 ml) ×: Over the reference value

[0029]

The polymer composition of the present invention provides a medical bag having a very good balance of flexibility, transparency, impact resistance and heat resistance. In particular, an infusion bag molded from a composition containing a metal salt of aromatic phosphoric acid as a nucleating agent has no problem in dissolution at 121 ° C. by a test method for a plastic container for infusion, and further has good heat resistance. .

[0030]

[Table 1]

[0031]

[Table 2]

[Brief description of drawings]

FIG. 1 is a front view of a medical bag according to the present invention.

FIG. 2 is a side view of the medical bag according to the present invention.

[Explanation of symbols]

 1 Medical Bag 2 Body 3 Mouth 4 Bottom 5 Hanging Piece

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display area C08K 5/52 KFM A61J 1/00 331A // (C08L 23/14 23:16 23:20) B29K 23:00

Claims (4)

[Claims] 1. A polymer composition for medical bags, comprising the following components (A) and (B). Component (A): Propylene as a main component, ethylene and at least one α-olefin selected from 4 to 12 carbon atoms has a content of 2.5 to 8% by weight and a melt flow rate of 0.1 to 20 g / 10. 70% to 90% by weight of propylene-α olefin random copolymer (B) component: Consists of the following (B1) component and (B2) component, and the weight ratio is ((B1) :( B2)) is 90:
10 to 10:90 ethylene polymer 30 to 10% by weight (B1) component; ethylene content 60 to 90% by weight, melt flow rate 1 to 20 g / 10 min ethylene-propylene copolymer (B2) component An ethylene-butene 1 copolymer having an ethylene content of 65 to 95% by weight and a melt flow rate of 1 to 50 g / 10 min. 2. A melt flow rate of 0.1 to 13 g /
The polymer composition according to claim 1, which has a memory effect of 1.5 to 2.5 for 10 minutes. 3. A metal salt of an aromatic phosphoric acid represented by the following general formula (I) is 0.001 to 0.5 part by weight per 100 parts by weight of the total amount of the components (A) and (B). The polymer composition according to claim 1, which comprises. General formula (I) (In the formula, R ¹ and R ² are each independently a hydrogen atom or an alkyl group having 1 to 18 carbon atoms, M is a metal of Group Ia or Group IIa, X is an alkylidene group, and n is Indicates an integer of 1 or 2.) 4. A medical bag, which is obtained by blow molding using the polymer composition according to claim 1.