JP2002265705A - Resin composition and container built of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resin composition excellent in heat resistance, flexibility, transparency, low-temperature impact resistance, bending fatigue, moldability, or the like, and to provide a container for use in medicines or for foods. SOLUTION: The resin composition comprises ethylene-α-olefin copolymers [A], [B], and [C], each having an ignition residue of 0.1 wt.% or less. Copolymer [A] has 0.920-0.965 g/cm<3> in density, 0.1-20 g/10 min in MFR, 1.5-3 in Mw/Mn, and 0.2 wt.% or less in n-heptane extraction ratio; [B] has 0.890-0.920 g/cm<3> in density, 0.1-20 g/10 min in MFR, 1.5-3 in Mw/Mn, and 10 wt.% or less in n-heptane extraction ratio; and [C] has 0.900-0.955 g/cm<3> in density, 0.1-30 g/10 min in MFR, and 3-8 in Mw/Mn. The blending ratio of [A] to [B] is 10:90-60:40, and the blending ratio of the mixture of [A] with [B] to [C] is 90:10-50:50.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition and a container, and more particularly, to a resin conforming to the Japanese Pharmacopoeia and having excellent heat resistance, flexibility, transparency, low-temperature impact resistance, flex fatigue and the like. The present invention relates to a medical container, a food container, and the like for accommodating a composition, a drug such as an infusion solution, blood, and the like.

[0002]

2. Description of the Related Art At present, polyvinyl chloride, polypropylene, polyethylene and the like are known as flexible containers commercially available for medical use. These containers do not require the introduction of air from the outside during use, and the containers themselves are squeezed by the atmospheric pressure together with the dripping of the contents medicine, so that there is safety and convenience in transportation. However, polyvinyl chloride contains highly toxic substances such as plasticizers and residual monomers, and has a problem that they elute into the drug. For example, with the exception of some parts, polypropylene and polyethylene have become mainstream.

[0003] In recent years, there has been a tendency for sterilization to be performed at a higher temperature due to an increase in awareness of safety and hygiene. As a material for the container, a material having higher heat resistance is desired. Polypropylene has excellent heat resistance and transparency, but has problems in flexibility and low-temperature impact resistance. Polyethylene is excellent in flexibility and transparency, but has problems with heat resistance, and various attempts have been made.However, a container with both heat resistance and flexibility that meets the physical properties required for medical containers in a well-balanced manner has been developed. Appearance was desired. The same has been desired for food containers.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to provide a resin composition having excellent heat resistance, flexibility, transparency, low-temperature impact resistance, flex fatigue, etc., and excellent moldability. And a container for medical use, food use, and the like.

[0005]

Means for Solving the Problems The present inventors have conducted intensive studies on the above-mentioned problems, and as a result, have found that three types of specific ethylene / α
-Found that heat resistance and flexibility / transparency can be imparted by blending an olefin copolymer, and also have good hygiene, low-temperature impact resistance and flex fatigue, and excellent moldability during molding. The present inventors have found that a resin composition capable of producing a container can be obtained, and have reached the present invention.

That is, the present invention comprises the following ethylene / α-olefin copolymers [A], [B] and [C], and (1) a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms. (2) density of 0.920 to 0.96
5 g / cm ³ , (3) melt flow rate is 0.1 to 2
0 g / 10 min, (4) weight average molecular weight (Mw) determined by gel permeation chromatography
And the number average molecular weight (Mn) ratio (Mw / Mn) is 1.5 to
3. (5) The extraction amount of n-heptane at 50 ° C. is 0.2
wt.% or less, (6) an ethylene / α-olefin copolymer [A] having a residue of 0.1% by weight or less according to the residue test for ignition on ignition specified in the Japanese Pharmacopoeia, (1) ethylene and carbon number 3 ~
An α-olefin copolymer having a density of 0.890 to 0.920 g / cm ³ ,
(3) melt flow rate of 0.1 to 20 g / 10 min, (4) weight average molecular weight (Mw) and number average molecular weight (Mn) determined by gel permeation chromatography Ratio (Mw / Mn)
1.5-3, (5) n-heptane extraction at 50 ° C. is 10 wt% or less, (6) residue by ignition residue test method specified in Japanese Pharmacopoeia is 0.1 wt% or less. Ethylene / α-olefin copolymer [B], (1) a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms,
(2) a density of 0.900 to 0.955 g / cm ³ ,
(3) a melt flow rate of 0.1 to 30 g / 10 minutes,
(4) The ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) determined by gel permeation chromatography is 3 to 8, [A],
(C) ethylene / α-olefin copolymer [C], which has a residue of 0.1% by weight or less according to the ignition residue test method specified in the Japanese Pharmacopoeia, which is larger than Mw / Mn of [B]. The compounding ratio (X) of the α-olefin copolymer [A] and the ethylene / α-olefin copolymer [B] is 10:90 to 6
0:40 and ethylene / α-olefin copolymer [A]
And a mixture ratio of the mixture of ethylene / α-olefin copolymer [B] and ethylene / α-olefin copolymer [C] (Y) is 90:10 to 50:50. And a container consisting of a twister.

Hereinafter, the present invention will be described in more detail.

[0008] The ethylene / α-olefin copolymer [A], the ethylene / α-olefin copolymer [B] and the ethylene / α-olefin copolymer [C] of the present invention contain ethylene and C3-C20. And α-olefins, for example, propylene, butene-1, 4-methyl-pentene-1, 3-methyl-butene-1, pentene-1, hexene-1, heptene −
1, octene-1, nonene-1, decene-1, undecene-1, dodecene-1, tridecene-1, tetradecene-1, pentadecene-1, hexadecene-1, heptadecene-1, octadecene-1, nonadecene-1, Eicosene-1 and the like, and two or more of these may be used in combination.

Here, the respective roles of the ethylene / α-olefin copolymer [A], the ethylene / α-olefin copolymer [B] and the ethylene / α-olefin copolymer [C] in the present invention will be described. I do. ethylene·
The purpose of using the α-olefin copolymer [A] is to secure heat resistance and transparency. The purpose of using the ethylene / α-olefin copolymer [B] is to secure flexibility, transparency, and low-temperature impact resistance. In addition, ethylene
The purpose of using the α-olefin copolymer [C] is to ensure insufficient heat resistance, flex fatigue, and moldability of the ethylene / α-olefin copolymer [A].

The ethylene / α-olefin copolymer [A] has a density range of 0.920 to 0.965 g / cm measured according to JIS K6760-1981.
In the range of ^3, preferably in the range of 0.920~0.955g / cm ^3, and more preferably in the range of 0.925~0.945g / cm ^3. Here, the density is 0.92
If it is less than 0 g / cm ³ , the heat resistance of the container becomes poor, and when heat treatment is performed, blocking or deformation occurs.
There is a problem that the container may be dissolved. On the other hand, when the density exceeds 0.965 g / cm ³ , flexibility, transparency and low-temperature impact resistance of a container become poor.

[0011] Ethylene / α-olefin copolymer [A]
Is 190 based on JIS K7210-1976.
The melt flow rate (hereinafter referred to as MFR) measured under a load of 2160 g at a temperature of 0.1 to 20 g / 10 min. Here, when the MFR is less than 0.1 g / 10 minutes, the fluidity of the resin composition is poor, and the moldability when manufacturing a container or the like is poor. On the other hand, MFR is 20 g / 1
If the time is longer than 0 minutes, the melt tension is reduced, so that the moldability is similarly deteriorated.

The ethylene / α-olefin copolymer [A] has a weight-average molecular weight (Mw) to number-average molecular weight (Mn) ratio determined by gel permeation chromatography (hereinafter referred to as Mw / Mn). ) Is 1.5
~ 3. Here, when Mw / Mn exceeds 3, the molecular weight distribution is widened and low molecular weight components having poor heat resistance are increased, so that the heat resistance of the container is deteriorated or devitrification after heat treatment is performed. And transparency deteriorates. On the other hand, when Mw / Mn is less than 1.5, the molecular weight distribution is narrow and the fluidity is poor, so that the moldability when molding a container or the like is poor.

[0013] Ethylene / α-olefin copolymer [A]
Means that the amount of n-heptane extracted at 50 ° C. is 0.2 wt.
% Or less. Here, when the amount of n-heptane extracted at 50 ° C. exceeds 0.2 wt%, low molecular weight components having poor heat resistance increase, and bleeding to the surface occurs when a container or the like is formed and subjected to heat treatment. There is a problem that transparency deteriorates and blocking occurs.

Ethylene / α-olefin copolymer [A]
Has a residue of 0.1% by weight or less according to the residue test for ignition on ignition specified in the Japanese Pharmacopoeia. Here, when the residue by the ignition residue test method prescribed in the Japanese Pharmacopoeia exceeds 0.1% by weight, the hygiene is deteriorated.

The ethylene / α-olefin copolymer [B] has a density range of 0.890 to 0.920 g / cm, measured according to JIS K6760-1981.
³ , which is smaller than the density of [A] and 0.895.
０．９0.920 g / cm ³ , preferably 0.900 g / cm ^3.
More preferably, it is in the range of 0.920 g / cm ³ . Here, when the density is less than 0.890 g / cm ³ , there is a problem that the heat resistance of the container is deteriorated, and blocking, deformation, dissolution of the container, and the like occur during the heat treatment. On the other hand, if the density exceeds 0.920 g / cm ³ , flexibility, transparency and low-temperature impact resistance of the container become poor.

[0016] Ethylene / α-olefin copolymer [B]
Has an MFR in the range of 0.1 to 20 g / 10 minutes. Here, when the MFR is less than 0.1 g / 10 minutes, the fluidity of the resin composition is poor, and the moldability when manufacturing a container or the like is poor. On the other hand, when the MFR is more than 20 g / 10 minutes, the melt tension is reduced, so that the moldability is similarly deteriorated.

The ethylene / α-olefin copolymer [B] has a Mw / Mn determined by gel permeation chromatography in the range of 1.5 to 3. Here, when Mw / Mn exceeds 3, the molecular weight distribution is widened and the low molecular weight component having poor heat resistance is increased, so that the heat resistance of the container or the like is deteriorated, or devitrification after heat treatment is performed. And transparency deteriorates. On the other hand, Mw /
When Mn is smaller than 1.5, the molecular weight distribution is narrow and the fluidity is poor, so that the moldability when molding a container or the like is poor.

Ethylene / α-olefin copolymer [B]
Means that the extractable amount of n-heptane at 50 ° C. is 10 wt%.
It is as follows. Here, when the amount of n-heptane extracted at 50 ° C. exceeds 10 wt%, low molecular weight components having poor heat resistance increase, so that bleeding to the surface occurs when a container or the like is molded and subjected to heat treatment, resulting in transparency. However, there is a problem that is deteriorated and blocking occurs.

Ethylene / α-olefin copolymer [B]
Has a residue of 0.1% by weight or less according to the residue test for ignition on ignition specified in the Japanese Pharmacopoeia. Here, when the residue by the ignition residue test method prescribed in the Japanese Pharmacopoeia exceeds 0.1% by weight, the hygiene is deteriorated.

Further, the ethylene / α-
The production method of the olefin copolymer [A] and the ethylene / α-olefin copolymer [B] are not particularly limited as long as the characteristics described above are satisfied. It can be produced using any catalyst system such as a Ziegler type catalyst mainly composed of a transition metal, a Phillips catalyst mainly composed of a chromium-based catalyst, and a Kaminski type catalyst mainly composed of metallocene. The ethylene / α-olefin copolymer [A] and the ethylene / α-olefin copolymer [B] used in the present invention are ethylene / α-olefins having Mw / Mn in the range of 1.5 to 3. A Kaminski-type copolymer mainly composed of metallocene or the like because of excellent mechanical strength when a resin composition obtained in a container or the like is easily obtained since the copolymer is easily obtained, and in particular, the composition distribution of ethylene and α-olefin is uniform. An ethylene / α-olefin copolymer produced using a catalyst is preferred. Further, since an ethylene / α-olefin copolymer having a small extraction amount of n-heptane at 50 ° C. can be easily obtained, Japanese Patent Application Laid-Open No.
Ethylene produced by the catalyst system described in
It is preferably an α-olefin copolymer.

As the Kaminski type catalyst, a transition metal compound (metallocene compound) mainly composed of a transition metal such as titanium, zirconium or hafnium and an ionic compound which reacts with an organometallic compound or a transition metal compound to form a stable anion A generally known catalyst system consisting of a combination of the above can be used. The Kaminsky type catalyst may be used alone or in combination of two or more. Specific examples of the Kaminsky catalyst include transition metal compounds such as bis (cyclopentadienyl) titanium dichloride, bis (cyclopentadienyl) zirconium dichloride, bis (cyclopentadienyl) hafnium dichloride, and bis (indenyl). ) Titanium dichloride, bis (indenyl)
Examples of organic metal compounds such as zirconium dichloride, bis (indenyl) hafnium dichloride, ethylenebis (indenyl) titanium dichloride, ethylenebis (indenyl) zirconium dichloride, ethylenebis (indenyl) hafnium dichloride, for example, trimethylaluminum, triethylaluminum, triisopropylaluminum Examples of the ionic compound that becomes a stable anion by reacting with a transition metal compound include those formed of, for example, lithium tetrakis (pentafluorophenyl) borate, N, N-dimethylanilinium tetrakis (pentafluorophenyl) borate, and the like.

The polymerization method at this time is not particularly limited, and a general polymerization method such as a gas phase method, a slurry method,
Any method such as a solution method and a high pressure method may be used. In addition, even when a single-stage or two-stage or more multi-stage polymerization is performed,
It can also be produced by mechanically blending more than one kind of ethylene / α-olefin copolymer.

Ethylene / α-olefin copolymer [C]
, The density range was measured conforming to JIS K6760-1981 ranges from 0.900~0.955g / cm ^3, preferably in the range of 0.905~0.950g / cm ^3, 0.910~0 More preferably, it is in the range of 0.935 g / cm ³ . Here, the density is 0.900 g /
If it is less than ³ cm ³ , the heat resistance of the container or the like will be poor, and there will be problems such as blocking, deformation, dissolution of the container, and the like during the heat treatment. Also, the density is
If it exceeds 0.955 g / cm ³ , flexibility, transparency and low-temperature impact resistance of a container or the like will be poor.

Ethylene / α-olefin copolymer [C]
Has an MFR in the range of 0.1 to 30 g / 10 minutes. Here, when the MFR is less than 0.1 g / 10 minutes, the fluidity of the resin composition is poor, and the moldability when manufacturing a container or the like is poor. On the other hand, when the MFR exceeds 30 g / 10 minutes, the melt tension is reduced, so that the moldability is similarly deteriorated.

Ethylene / α-olefin copolymer [C]
Has an Mw / Mn determined by gel permeation chromatography in the range of 3 to 8,
It is larger than Mw / Mn of [A] and [B]. Where Mw
When / Mn is more than 8, the molecular weight distribution is widened, and the low molecular weight component having poor heat resistance is increased, so that the heat resistance when the obtained resin composition is molded into a container or the like deteriorates or after heat treatment is performed. Devitrification increases, and transparency deteriorates. On the other hand, when Mw / Mn is less than 3, the molecular weight distribution is narrow and the fluidity is poor, so that the moldability when molding a container or the like is poor.

Ethylene / α-olefin copolymer [C]
Has a residue of 0.1% by weight or less according to the residue test for ignition on ignition specified in the Japanese Pharmacopoeia. Here, when the residue by the ignition residue test method prescribed in the Japanese Pharmacopoeia exceeds 0.1% by weight, the hygiene is deteriorated.

Ethylene / α-olefin copolymer [C]
Is not particularly limited as long as the above-mentioned physical properties are satisfied. Among them, ethylene / α-olefin copolymer having Mw / Mn in the range of 3 to 8 is preferred. It is easy to obtain, especially because it has excellent heat resistance when molded into a container or the like from a resin composition obtained from a wide composition distribution, and is mainly composed of a Ziegler-type catalyst mainly composed of a titanium-based transition metal and a chromium-based catalyst. It is preferable to use a catalyst system such as a Phillips catalyst.

The composition ratio (X) of the ethylene / α-olefin copolymer [A] and the ethylene / α-olefin copolymer [B] in constituting the resin composition of the present invention is 10:90.
６０60: 40. When the proportion of the ethylene / α-olefin copolymer [A] is less than 10% by weight, flexibility and low-temperature impact resistance of a container or the like are reduced. When the proportion of the ethylene / α-olefin copolymer [A] exceeds 60% by weight, the heat resistance of a container or the like is reduced.

Ethylene / α-olefin copolymer [A]
The mixture ratio (Y) of the mixture of the ethylene / α-olefin copolymer [B] and the ethylene / α-olefin copolymer [C] is 90:10 to 50:50. ethylene·
When the ratio of the α-olefin copolymer [C] is less than 10% by weight, the moldability when producing a container or the like is reduced.
If the proportion of the ethylene / α-olefin copolymer [C] is more than 50% by weight, the bending fatigue of a container or the like is reduced.

The moldability is important for stable production of the container. In particular, when heat is generated in an extruder, the molded article may be burnt or gel. Further, when there is a fluctuation in the discharge in the extruder, unevenness in the thickness of the molded product occurs, which makes it difficult to manufacture a product with stable quality. Further, heat resistance is important when heat-treating a container filled with contents, and is a very important property for ensuring hygiene, that is, safety. In the case of medical containers such as infusion bags, heat treatment is required by the Japanese Pharmacopoeia, and it is difficult to commercialize a medical container unless the container can withstand the heat treatment. Further, also in a food container, generally, a heat treatment is required after filling the food, and it is difficult to commercialize the same as a medical container. In addition, transparency is important for confirming the filling state of the filler and foreign substances when the container is filled with the contents. In the case of medical containers such as infusion bags, the Japanese Pharmacopoeia sets a reference value for transparency, and the transmittance of the container after the heat treatment must be 55% or more. Also,
Flexibility, for example, in the case of containers such as infusion bags,
It is important for improving the self-waste liquid property of the contents. In addition, bending fatigue is important when transporting a container filled with contents to reduce liquid leakage or the like due to bending of the container during transportation. Also, low-temperature impact resistance, especially improvement in drop resistance at low temperatures, is important because cracks are unlikely to occur even when accidentally dropped when taking out a filled container stored at low temperature in a refrigerator or the like. Nature.

The resin composition of the present invention may contain, if necessary, an antioxidant, an antiblocking agent, an antistatic agent, a lubricant, a weathering agent as long as the object of the present invention is not substantially impaired.
Light stabilizers, ultraviolet absorbers, inorganic and organic fillers, nucleating agents,
Known additives such as a clarifying agent, a coloring agent, an organic peroxide, a catalyst neutralizing agent, a plasticizer, an antifogging agent, an organic / inorganic pigment, and a dispersant may be contained.

The method of molding the resin composition of the present invention into a container or the like is not particularly limited, and may be a generally known method, such as water-cooled or air-cooled inflation molding, blow molding, and tube. Molding methods such as molding, rotational molding, injection molding, and injection (biaxial stretching) blow molding are used. In particular, water-cooled inflation molding is preferred because of its excellent hygiene and transparency. Further, using these molding methods, the container may be molded in a single layer or a multilayer.

[0033]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

-Measurement of Density- In accordance with JIS K6760-1976, a sample immersed in hot water at 100 ° C for 1 hour and then cooled to room temperature was measured using a density gradient tube kept at 23 ° C. .

Measurement of Melt Flow Rate 190 ° C., 21 in accordance with JIS K6760-1981
It was measured under a load of 60 g.

-Measurement of Mw / Mn- Gel permeation chromatography (manufactured by Nippon Millipore Co., Ltd., apparatus name "ALC / GPC150C" (column: manufactured by Tosoh Corporation, trade name "GMHHR-H")
(S) ", 3 solvents, 1,2,4-trichlorobenzene, temperature: 140 ° C., flow rate 1.0 ml / min, injection concentration 1
mg / ml, injection volume 300 μl).
The column elution volume was calibrated by universal calibration using standard polystyrene manufactured by Tosoh Corporation.

-Measurement of n-heptane extraction amount- About 10 g of a pulverized sample of a 200 mesh pass was precisely weighed,
This was calculated by adding 0 ml of n-heptane and performing extraction at 50 ° C. for 2 hours, evaporating the solvent from the extract, and drying and solidifying the extract to determine the ratio of the weight of the extract to the initial weight.

Residue on Ignition Test Method A sample 50 was prepared according to the method for residue on ignition specified in the Japanese Pharmacopoeia.
g was precisely weighed, put in a platinum dish, burned with a gas burner, and further ashed at 650 ° C. for 1 hour in an electric furnace to determine the ratio of the weight of the residue to the initial weight. Calculated.

—Evaluation of Moldability— Judgment was made based on the stability of the extruder when the composition was used to mold at a resin temperature of 195 ° C. using a Placo 45 mmφ single-layer water-cooled inflation molding machine.

：: No heat generation, no discharge fluctuation.

X: Heat is generated, and there is ejection fluctuation.

-Evaluation of heat resistance- According to the Japanese Pharmacopoeia, a container was set in an autoclave by a high-pressure steam method, heated at 115 ° C for 30 minutes, cooled to room temperature, and then taken out. The appearance was evaluated by observing the following items.

The evaluation criteria are shown below.

Deformation: The wavy state of the container was observed.

：: Deformation was small with almost no undulation.

×: The container had large waves and the container was greatly deformed.

Rough skin: The rough surface of the container was observed.

：: No spot-like pattern was observed on the surface of the container.

×: Several spot-like patterns were observed on the surface of the container.

Blocking: The dissolution state of the inner surface of the container was observed.

：: No dissolution of the inner surface of the container was observed.

×: Dissolution of the inner surface of the container was observed. -Evaluation of Transparency- Hitachi UV Spectrophotometer (220A)
, A sample piece having a width of 9.5 mm and a length of 50 mm was cut out from the vicinity of the center of the body of the container after the evaluation of the heat resistance, and the transmittance at a wavelength of 450 nm was measured in pure water.

-Evaluation of low-temperature impact resistance- After the evaluation of heat resistance, the container was allowed to stand in a constant temperature room at 4 ° C for 12 hours. The container was repeatedly dropped five times vertically from the height to the floor, and the state of the container was observed.

-Evaluation of Flexibility- Tensile secant modulus at 5% strain (hereinafter referred to as 5% modulus) was measured in accordance with JIS K7127-1989. The lower the numerical value, the better the flexibility. .

-Evaluation of Flexural Fatigue Property- A test piece having a width of 10 mm and a length of 100 mm was cut out from the vicinity of the center of the body of the container after the evaluation of the heat resistance, fixed to a jig, and folded vertically 5000 times. After that, using an autograph (trade name DCS-500) manufactured by Shimadzu Corporation,
Conduct a tensile test at a tensile speed of 300 mm / min, measure the tensile fracture strength and tensile elongation before and after folding, evaluate the bending fatigue properties by the rate of change in strength before and after folding, and find that the rate of change is small. The better.

EXAMPLES Synthesis Example 1 [Preparation of Modified Clay Compound] To 1500 mL of water, 30 mL of 37% hydrochloric acid and 89.1 g of N, N-dimethyl-octadecylamine were added, and an aqueous solution of N, N-dimethyl-octadecyl ammonium hydrochloride was added. Prepared. Average particle size 7.8
300 g of montmorillonite (prepared by crushing Kunipia F (trade name, manufactured by Kunimine Industries Co., Ltd.) with a jet crusher) was added to the aqueous hydrochloride solution and allowed to react for 6 hours. After completion of the reaction, the reaction solution was filtered, and the obtained cake was dried under reduced pressure for 6 hours to obtain a modified clay compound (360 g).
The introduced amount of organic cation was 1.0 mmol / g.

[Preparation of Catalyst] In a 20 L stainless steel container under a nitrogen atmosphere, 3.3 L of heptane and 3.5 mol (2.8 L) of a heptane solution of triethylaluminum (20 wt% dilution) per aluminum atom were obtained. 300 g of the modified clay compound was added and stirred for 1 hour. Diphenylmethylene (cyclopentadienyl) (2,7-di-t-butyl-9-fluorenyl) zirconium dichloride was added thereto at a rate of 10 per zirconium atom.
After adding mmol, the mixture was stirred for 12 hours. In the resulting suspension,
Aliphatic saturated hydrocarbon solvent (IP solvent 2835)
(Manufactured by Idemitsu Petrochemical Co., Ltd.)
A catalyst was prepared (zirconium concentration 0.67 mmol /
L).

[Preparation of additive solution] 3 L under nitrogen atmosphere
2.1 L of heptane, a heptane solution of triethylaluminum (20 wt% diluted product) in an amount of 1.1 mol per aluminum atom (0.9 L) and 1.55 g of tetrabenzyltitanium (3.
75 mmol), and the resulting solution was transferred to a dedicated pressure vessel under a nitrogen atmosphere to prepare an additive solution (titanium concentration: 1.25 mmol /
L).

[Polymerization] Polymerization was carried out using a reactor equipped for high-temperature and high-pressure polymerization. Ethylene and hexene-1 were continuously pressed into the reactor to reduce the total pressure to 900 kg / cm ^2.
The hexene-1 concentration was set to 17.7 mol%. Then, the reactor was stirred at 1500 rpm. Then, the catalyst was continuously supplied to the upper portion of the reactor, and polymerization was performed so that the average temperature was maintained at 185 ° C. In parallel, the additive solution is continuously supplied to the lower part of the reactor so that the amount of titanium is equal to the amount of zirconium supplied,
A pellet [A1] of an ethylene / hexene-1 copolymer was obtained. The obtained ethylene / hexene-1 copolymer [A
1], density = 0.930 g / cm ³ , MFR = 1.8
g / 10 min, Mw / Mn = 1.9, n-heptane extraction amount was 0.1% by weight, and ignition residue was 0.02% by weight.

Synthesis Example 2 Except that the concentration of hexene-1 during polymerization was 51 mol%
Is polymerized in the same manner as in Synthesis Example 1, and
A pellet [B1] of the sen-1 copolymer was obtained. Got
The ethylene / hexene-1 copolymer [B1] has a density =
0.911 g / cm ^Three, MFR = 2.2 g / 10 min, M
w / Mn = 2.1, n-heptane extraction amount is 1.0 weight
% And the residue on ignition was 0.03% by weight.

Synthesis Example 3 Polymerization was carried out in the same manner as in Synthesis Example 1 except that the hexene-1 concentration at the time of polymerization was changed to 37.7 mol% to obtain pellets [C2] of an ethylene / hexene-1 copolymer. Was. The obtained ethylene / hexene-1 copolymer [C2] has a density =
0.919 g / cm ³ , MFR = 2.2 g / 10 min, M
w / Mn = 2.2, the amount of n-heptane extracted was 0.85% by weight, and the residue on ignition was 0.03% by weight.

Example 1 [Preparation of Composition] 15% by weight of the ethylene / α-olefin copolymer [A1] obtained in Synthesis Example 1 as the ethylene / α-olefin copolymer [A], -60% by weight of the ethylene / α-olefin copolymer [B1] obtained in Synthesis Example 2 as the olefin copolymer [B],
As the ethylene / α-olefin copolymer [C], an ethylene / α-olefin copolymer [C1] ((Nipolon-Z ZF, manufactured by Tosoh Corporation, obtained using a Ziegler catalyst)
230 (MFR = 2.0 g / 10 min, density = 0.920)
g / cm ³ , Mw / Mn = 4.6, residue on ignition 0.03
25% by weight in a tumbler blender.
The composition was obtained by dry blending for 5 minutes. X = 20: 8
0, Y = 75: 25. [Molding of Composition] Using the composition obtained in the above procedure, a single layer water-cooled 45 mmφ water-cooled inflation molding machine made of Placo, resin temperature = 195 ° C., take-off speed = 6 m / min, folding diameter 135 mm, thickness: A 250 μm tubular film was formed. The moldability during the main molding was good. [Production of Container] A tubular sample having a length of 200 mm was cut out from the tubular film obtained by the above-mentioned molding, and one opening was sealed with an impulse sealer manufactured by Fuji Impulse to a width of 10 mm from the end of the opening. Next, 400 ml of pure water was filled, and the other opening was sealed with an impulse sealer manufactured by Fuji Impulse with a width of 10 mm from the end of the opening so that the amount of air inside became 50 cc. [Heat treatment] The container obtained above was set in a high-temperature and high-pressure cooking sterilizer manufactured by Hisaka Seisakusho, and heat-treated at 115 ° C for 30 minutes, and the sample was cooled to room temperature. [Evaluation of Heat Resistance] The physical properties after the heat treatment were evaluated. As a result, no deformation and roughening and no blocking were observed, the appearance was good, and the heat resistance was good. [Evaluation of Physical Properties] The transmittance was 85% and the 5% modulus was 12
At 1 MPa, the rate of change in tensile strength at break was 3%, and the rate of change in tensile elongation at break was 2%, and no cracking occurred when dropped at low temperature.

Example 2 The ethylene / α-olefin copolymer of Example 1 [A1]
Was carried out in the same manner as in Example 1, except that the amount of the compound was 25% by weight and the amount of the ethylene / α-olefin copolymer [B1] was 50% by weight. As a result, the moldability was good, the deformation, the surface roughness and the blocking after the heat treatment were not observed, the appearance was good, and the heat resistance was good.
The transmittance is 78%, the 5% modulus is 130 MPa, the rate of change in tensile breaking strength is 7%, and the rate of change in tensile breaking elongation is 5%.
No cracking occurred during the low temperature drop.

Example 3 The ethylene / α-olefin copolymer of Example 1 [A1]
Except that the amount of the ethylene / α-olefin copolymer [B1] was 50% by weight and the amount of the ethylene / α-olefin copolymer [C1] was 40% by weight. The same operation as in Example 1 was performed. As a result, the moldability was good, the deformation, the surface roughness and the blocking after the heat treatment were not observed, the appearance was good, and the heat resistance was good. The transmittance is 78%, and the 5% modulus is 118.
MPa, the rate of change in tensile breaking strength was 2%, and the rate of change in tensile elongation at break was 3%, and no cracking occurred when dropped at low temperature.

Example 4 The ethylene / α-olefin copolymer of Example 1 [A1]
Except that the compounding amount of the ethylene / α-olefin copolymer [B1] was 35% by weight and the compounding amount of the ethylene / α-olefin copolymer [C1] was 35% by weight. The same operation as in Example 1 was performed. As a result, the moldability was good, the deformation, the surface roughness and the blocking after the heat treatment were not observed, the appearance was good, and the heat resistance was good. The transmittance is 79% and the 5% modulus is 138.
MPa, the rate of change in tensile fracture strength was 7%, and the rate of change in tensile elongation at break was 9%, and no cracking occurred when dropped at low temperature.

Example 5 The ethylene / α-olefin copolymer of Example 1 [A1]
Was 25% by weight, the amount of the ethylene / α-olefin copolymer [B1] was 60% by weight, and the amount of the ethylene / α-olefin copolymer [C1] was 15% by weight. The same operation as in Example 1 was performed. As a result, the moldability was good, the deformation, the surface roughness and the blocking after the heat treatment were not observed, the appearance was good, and the heat resistance was good. Transmittance 70%, 5% modulus 128
MPa, the rate of change in tensile fracture strength was 5%, and the rate of change in tensile elongation at break was 7%, and no cracking occurred when dropped at low temperature.

Comparative Example 1 The ethylene / α-olefin copolymer of Example 1 [C1]
Was performed in the same manner as in Example 1, except that the ethylene / α-olefin copolymer [C2] obtained in Synthesis Example 3 was used in an amount of 25% by weight. As a result, the moldability was poor, deformation after heat treatment, skin roughening and blocking occurred, and it was judged that use as a container was difficult due to poor appearance. The transmittance was 77%, the 5% modulus was 125 MPa, the rate of change in tensile breaking strength was 0%, and the rate of change in tensile elongation at break was 0%, and no cracking occurred when dropped at low temperature.

Comparative Example 2 The ethylene / α-olefin copolymer of Example 1 [A1]
30% by weight of an ethylene / α-olefin copolymer [B
1] was 35% by weight, and ethylene / α obtained in Synthesis Example 3 was used instead of the ethylene / α-olefin copolymer [C1].
-The same operation as in Example 1 was performed except that 35% by weight of the olefin copolymer [C2] was used. As a result, the moldability was poor, deformation after heat treatment, skin roughening and blocking occurred, and it was judged that use as a container was difficult due to poor appearance. The transmittance was 65%, the 5% modulus was 152 MPa, and the rate of change in tensile breaking strength was 45.
%, And the rate of change in tensile elongation at break was 50%, and no cracking occurred when dropped at low temperature.

Comparative Example 3 The ethylene / α-olefin copolymer of Example 1 [A1]
60% by weight of an ethylene / α-olefin copolymer [B
[1] was carried out in the same manner as in Example 1 except that 40% by weight of [1] was used and only two components were blended. As a result, the moldability was poor, deformation after heat treatment, skin roughening and blocking occurred, and it was judged that use as a container was difficult due to poor appearance. The transmittance was 60%, the 5% modulus was 185 MPa, and the rate of change in tensile breaking strength was 65.
%, And the rate of change in tensile elongation at break was 63%. In the evaluation at a low temperature drop, cracks occurred at the fifth drop.

Comparative Example 4 The ethylene / α-olefin copolymer of Example 1 [A1]
25% by weight of an ethylene / α-olefin copolymer [B
1] of 50% by weight, instead of the ethylene / α-olefin copolymer [C1], high-pressure low-density polyethylene, manufactured by Tosoh, Petrocene 0354 (density = 0.920 g / cm
³ , MFR = 3.0, Mw / Mn = 9.6) except that the evaluation was performed in the same manner as in Example 1. Although the moldability was good, it was judged that deformation after heat treatment, skin roughness and blocking occurred, and the appearance was poor, so that use as a container was difficult. Further, the transmittance was 68%, the 5% modulus was 149 MPa, and the rate of change in tensile breaking strength was 82.
%, And the rate of change in tensile elongation at break was 90%, and cracks occurred during the third drop in the low-temperature drop evaluation.

Comparative Example 5 The ethylene / α-olefin copolymer of Example 1 [A1]
, The amount of the ethylene / α-olefin copolymer [B1] was 20% by weight, and the amount of the ethylene / α-olefin copolymer [C1] was 5% by weight. The same operation as in Example 1 was performed. As a result, the moldability was poor, the deformation and the surface roughness and the blocking after heat treatment were not observed, the appearance was good and the heat resistance was good, but the transmittance was 58% and the 5% modulus was 205.
MPa, the rate of change in tensile breaking strength is 90%, and the rate of change in tensile elongation at break is 93%. In the low-temperature drop evaluation, cracking occurs at the fifth drop, and there is no problem with heat resistance. It was judged that use as a container was difficult because of poor flexibility, flex fatigue, and low-temperature impact resistance.

Table 1 shows the physical properties of the resins used in the above Examples.
Table 2 shows the evaluation results of the compounding ratios and the physical properties of the resins of the examples.
Table 3 shows the results of evaluation of the compounding ratio and physical properties of the resin of Comparative Example.

[0073]

[Table 1]

[Table 2]

[Table 3]

The resin composition obtained by the present invention and a container comprising the same are excellent in moldability, heat resistance, flexibility and transparency, and also excellent in bending fatigue and low-temperature impact resistance. It is suitable for medical containers for storing liquid solutions, drugs, agents, blood, etc., and food containers.

Claims (3)

[Claims] 1. An ethylene / α-olefin copolymer [A], [B] and [C], which is (1) a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms,
(2) a density of 0.920 to 0.965 g / cm ³ ,
(3) a melt flow rate of 0.1 to 20 g / 10 minutes,
(4) The ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) determined by gel permeation chromatography is 1.5 to 3, (5) 50
The amount of n-heptane extracted at 0.2 ° C.
(6) Ethylene / α-olefin copolymer [A] having a residue of 0.1% by weight or less according to the ignition residue test method specified in the Japanese Pharmacopoeia, (1) ethylene and α-olefin copolymer having 3 to 20 carbon atoms α-olefin copolymer, (2) a density of 0.890 to
(3) a melt flow rate of 0.1 to 20 g / cm ³ , which is smaller than the density of [A].
10 minutes, (4) the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) determined by gel permeation chromatography is 1.5 to 3,
(5) The extraction amount of n-heptane at 50 ° C. is 10 wt%.
Hereinafter, (6) an ethylene / α-olefin copolymer [B] whose residue by the ignition residue test method specified in the Japanese Pharmacopoeia is 0.1% by weight or less, (1) ethylene and a carbon number of 3 to 3 20. An α-olefin copolymer having a density of 0.2.
900 to 0.955 g / cm ³ , (3) melt flow rate of 0.1 to 30 g / 10 min, (4) weight average molecular weight (Mw) and number average molecular weight (Mn) determined by gel permeation chromatography ) Ratio (Mw /
Mn) is 3 to 8 and is larger than Mw / Mn of [A] and [B]. (5) Residue by ignition residue test method specified in Japanese Pharmacopoeia is 0.1% by weight or less. Ethylene / α-olefin copolymer [C], ethylene / α-olefin copolymer [A] and ethylene / α-olefin copolymer [B]
Is a mixture of ethylene / α-olefin copolymer [A] and ethylene / α-olefin copolymer [B] and ethylene / α-olefin copolymer [X] is 10:90 to 60:40. C] is 90: 10-5
A resin composition characterized by the ratio of 0:50. 2. A container comprising the resin composition according to claim 1. 3. A liquid container comprising the resin composition according to claim 1.