Polyethylene resin composition, laminate comprising same, and medical container using laminate

Abstract

Provided are: a polyethylene laminate that exhibits excellent flexibility, barrier properties, and cleanliness (a low occurrence of fine particles), that does not deform even after sterilization treatment at 121° C., and that maintains high transparency; and a medical container using same. The medical container is configured by layering: an outer layer and an inner layer that comprise from 20 to 80 wt % of a high-density polyethylene (A) having specific properties, from 0 to 50 wt % of a linear low-density polyethylene (B1), and from 5 to 40 wt % of an ethylene-based polymer (C); and an intermediate layer that comprises from 10 to 40 wt % of the high-density polyethylene (A) and from 60 to 90 wt % of the linear low-density polyethylene (B1).

Claims

1. A polyethylene resin composition comprising from 20 to 80 wt % of a high-density polyethylene (A) satisfying characteristics (a) and (b) described below, from 0 to 50 wt % of a linear low-density polyethylene (B1) satisfying characteristics (c) and (d) described below, and from 5 to 40 wt % of an ethylene-based polymer satisfying characteristics (e) to (h) described below, a total of (A), (B1), and (C) being 100 wt %: (a) Density is from 945 to 970 kg/m.sup.3; (b) MFR measured at 190° and load of 2.16 kg in conformance with JIS K69221 is from 0.1 to 15.0 g/10 min; (c) Density is from 890 to 915 kg/m.sup.3; (d) MFR measured at 190° and load of 2.16 kg in conformance with JIS K6922-1 is from 0.1 to 15.0 g/10 min; (e) Density is from 930 to 960 kg/m.sup.3; (f) MFR measured at 190° and load of 2.16 kg in conformance with JIS K6922-1 is from 0.1 to 15.0 g/10 min; (g) Two peaks appear in molecular weight measurement by gel permeation chromatography, and a ratio (Mw/Mn) of weight-average molecular weight (Mw) to number-average molecular weight (Mn) is from 2.0 to 7.0; (h) A fraction having Mn of not less than 100,000 obtained by molecular-weight fractionation has 0.15 or more long-chain branches per 1,000 carbons of a main chain.

2. The polyethylene resin composition according to claim 1, wherein the high-density polyethylene (A) satisfies characteristics (i) and (j) described below in addition to the characteristics (a) and (b): (i) A ratio (Mw/Mn) of weight-average molecular weight (Mw) to number-average molecular weight (Mn) determined by gel permeation chromatography is not greater than 3.0; (j) Residue according to the Residue on Ignition Test set forth in the Japanese Pharmacopoeia is not greater than 0.02 wt %.

3. The polyethylene resin composition according to claim 1, wherein the linear low-density polyethylene (B1) satisfies characteristics (k) and (l) described below in addition to the characteristics (c) and (d): (k) A ratio (Mw/Mn) of weight-average molecular weight (Mw) to number-average molecular weight (Mn) determined by gel permeation chromatography is not greater than 3.0; (l) An n-heptane extraction quantity at 50° C. is not greater than 1.5 wt %.

4. The polyethylene resin composition according to claim 1, wherein Mw/Mn of the ethylene-based polymer (C) is from 3.0 to 6.0, and Mn is not less than 15,000.

5. The polyethylene resin composition according to claim 1, wherein a proportion of components of the ethylene-based polymer (C), the proportion having Mn not less than 100,000 when fractioned by molecular weight, is less than 40% of all of the ethylene-based polymer (C).

6. The polyethylene resin composition according to claim 1, wherein the composition comprises from 20 to 70 wt % of the high-density polyethylene (A), from 10 to 50 wt % of the linear low-density polyethylene (B1), and from 5 to 40 wt % of the ethylene-based polymer (C).

7. A laminate containing an outer layer, an inner layer, and an intermediate layer disposed therebetween, the outer layer and the inner layer comprising the polyethylene resin composition described in claim 1, the intermediate layer comprising from 10 to 40 wt % of the high-density polyethylene (A) satisfying at least the above characteristics (a) and (b) and from 60 to 90 wt % of the linear low-density polyethylene (B1) satisfying he above characteristics (c) and (d), a total of (A) and (B1) being 100 wt %.

8. The laminate according to claim 7, wherein the high-density polyethylene (A) used in the intermediate layer satisfies the characteristics (a), (b), (i), and (j).

9. The laminate according to claim 7, wherein the linear low-density polyethylene (B1) used in the intermediate layer satisfies the characteristics (c), (d), (k), and (l).

10. The laminate according to claim 7, wherein the intermediate layer comprises a resin composition containing from 5 to 30 wt % of a linear low-density polyethylene (B2) satisfying characteristics (m) and (n) described below, relative to a total of 100 wt % of the high-density polyethylene (A) and the linear low-density polyethylene (B1): (m) Density is from 920 to 945 kg/m.sup.3; (n) MFR is from 0.1 to 15.0 g/10 min.

11. A medical container possessing a holding portion holding a drug solution, at least the holding portion comprising the laminate described in claim 7.

12. The medical container according to claim 11, wherein the holding portion holding a drug solution is formed by molding a laminate molded in a film shape into a bag shape by hot sheet molding.

13. The medical container according to claim 11, wherein the holding portion holding a drug solution is formed by molding a laminate into a bottle shape by blow molding.

14. The medical container according to claim 11, wherein, even after sterilization treatment at 121° C., there is no deformation of the container and light transmittance measured at wavelength 450 nm in purified water is not less than 70%.

Description

EXAMPLES

(1) The present invention will be described in further detail below while giving examples, but the present invention is not limited by these examples.

(2) A. Resin

(3) Various properties of the resins used in the examples and comparative examples were evaluated by the following methods.

(4) <Molecular Weight, Molecular Weight Distribution>

(5) The weight-average molecular weight (Mw), the number-average molecular weight (Mn), the ratio (Mw/Mn) of weight-average molecular weight (Mw) to number-average molecular weight (Mn), and the peak top molecular weight (Mp) were measured by GPC. Using a GPC instrument (brand name HLC-8121 GPC/HT manufactured by Tosoh Corporation) and a column (brand name TSKgel GMHhr-H (20) HT manufactured by Tosoh Corporation), the column temperature was set to 140° C., and molecular weight was measured using 1,2,4-trichlorobenzene as an eluent. The measurement sample was prepared at a concentration of 1.0 mg/mL, and 0.3 mL of this sample was injected and measured. A molecular weight calibration curve was created using a polystyrene sample of known molecular weight. Mw and Mn were determined as values based on linear polyethylene.

(6) <Fractionation by Molecular Weight>

(7) For fractionation by molecular weight, a column (diameter 21 mm, length 60 cm) filled with glass beads was used as the column. The column temperature was set to 130° C., and 1 g of sample was dissolved in 30 mL of xylene and this was injected. Then, the distillate was removed using xylene/2-ethoxyethanol in a ratio of 5/5 as the developer solvent. After that, the components remaining in the column were distilled out using xylene as a developer solvent, and a polymer solution was obtained. Ethanol was added in an amount equal to 5 times the amount of the obtained polymer solution, and the polymer component was precipitated out, and by filtration and drying, the component having Mn of not less than 100,000 was recovered.

(8) <Long-Chain Branches>

(9) For the number of long-chain branches, the number of branches equal to or longer than a hexyl group was measured by .sup.13C-NMR using a nuclear magnetic resonance instrument model JNM-GSX400 manufactured by JEOL Ltd. The solvent was benzene-d6/orthodichlorobenzene (volume ratio 30/70). The number of long-chain branches were determined from the average of the peaks of α-carbon (34.6 ppm) and β-carbon (27.3 ppm) as the number per 1,000 carbons (chemical shift 30 ppm) of main-chain methylene.

(10) <Ignition Residue>

(11) In conformance with the Residue on Ignition Test set forth in the Japanese Pharmacopoeia, 50 g of sample was weighed out and then put in a platinum dish and combusted using a gas burner, and then completely ashed in an electric furnace at 650° C. for 1 hr. The weight of the residue at this point was measured, and ignition residue was calculated by determining the percentage relative to the initial weight.

(12) <n-Heptane Extraction Quantity>

(13) Approximately 10 g of crushed sample that passed through 200 mesh was weighed out and added to 400 mL of n-heptane, and extraction was performed for 2 hr at 50° C. The solvent was evaporated off from the extract, and after drying and solidifying, the n-heptane extraction quantity was calculated by determining the percentage of the weight of the obtained extract relative to the initial weight.

(14) <Density>

(15) Density was measured by the density gradient tube method in conformance with JIS K6922-1.

(16) <MFR>

(17) MFR (melt flow rate) was measured in conformance with JIS K6922-1.

(18) <Melt Tension>

(19) A sample, to which thermal stabilizers (1500 ppm of Irganox 1010, 1500 ppm of Irgafos 168, both manufactured by Ciba Specialty Chemicals Inc.) had been added, was kneaded for 30 min under nitrogen flow at 190° C. at a rotation speed of 30 rpm using an internal mixer (brand name Labo Plastomill manufactured by Toyo Seiki Seisaku-Sho, Ltd.), and the resulting substance was used as the sample for melt tension measurement.

(20) In melt tension measurement, a die, 8 mm in length and 2.095 mm in diameter, was mounted on a capillary viscometer (brand name Capillograph manufactured by Toyo Seiki Seisaku-Sho, Ltd.) having a barrel diameter of 9.55 mm so as to result in an inflow angle of 90°. The temperature was set to 160° C., the piston fall rate to 10 mm/min, and the draw ratio to 47, and the load (mN) required to pull was taken as the melt tension. When the maximum draw ratio was less than 47, the load (mN) required to pull at the maximum draw ratio without breaking was taken as the melt tension.

(21) Resins produced by the following methods and commercially available products were used in the examples and comparative examples.

(22) (1) High-Density Polyethylene

(23) (A)-1

(24) [Preparation of Modified Clay]

(25) In a mixed solvent of 4.8 L of deionized water and 3.2 L of ethanol, 354 g of dimethylbehenylamine ((C.sub.22H.sub.45)(CH.sub.3).sub.2N) and 83.3 mL of 37% hydrochloric acid were added, and a dimethylbehenylamine hydrochloride solution was prepared. To this solution, 1,000 g of synthetic hectorite was added and stirred overnight, and after the obtained reaction solution was filtered, the solid content was washed adequately with water. When the solid content was dried, 1,180 g of organic modified clay compound was obtained. The moisture content measured by an infrared moisture meter was 0.8%. Then, this organic modified clay compound was crushed, and the average particle size was adjusted to 6.0 μm.

(26) [Preparation of Polymerization Catalyst]

(27) In a 5-L flask, 450 g of the organic modified clay compound obtained in “Preparation of modified clay compound” and 1.4 kg of hexane were added, and then 1.78 kg of a hexane solution of 20 wt % triisobutylaluminum (1.8 mol) and 7.32 g (18 mmol) of bis(n-butyl-cyclopentadienyl)zirconium dichloride were added, and this was heated to 60° C. and stirred for 1 hr. The reaction solution was cooled to 45° C. and left to stand for 2 hr, and then the supernatant was removed by tilting. Then, 1.78 kg of a hexane solution of 1 wt % triisobutylaluminum (0.09 mol) was added, and this was reacted for 30 min at 45° C. The reaction solution was left to stand for 2 hr at 45° C., and then the supernatant was removed by tilting. Then, 0.45 kg of a hexane solution of 20 wt % triisobutylaluminum (0.45 mol) was added, this was re-diluted with hexane to make a total of 4.5 L, and a polymerization catalyst was thereby prepared.

(28) [Production of (A)-1]

(29) In a polymerization reactor of internal volume 300 L, 135 kg/hr of hexane, 20.0 kg/hr of ethylene, 0.3 kg/hr of butene-1, 5 NL/hr of hydrogen, and the polymerization catalyst obtained in “Preparation of polymerization catalyst” were continuously supplied. Furthermore, triisobutylaluminum was also supplied continuously as a promoting catalyst to make the concentration thereof to 0.93 mmol/kg in hexane. The polymerization temperature was controlled to 85° C. The obtained high-density polyethylene ((A)-1) had an MFR of 1.0 g/10 min and a density of 952 kg/m.sup.3. The evaluation results of the basic characteristics of (A)-1 are shown in Table 1.

(30) (A)-2

(31) [Preparation of Modified Clay]

(32) A modified clay compound was prepared by the same method as (A)-1.

(33) [Preparation of Polymerization Catalyst]

(34) A polymerization catalyst was prepared by the same method as (A)-1.

(35) [Production of (A)-2]

(36) In a polymerization reactor of internal volume 300 L, 135 kg/hr of hexane, 20.0 kg/hr of ethylene, 0.4 kg/hr of butene-1, 8 NL/hr of hydrogen, and the polymerization catalyst obtained in “Preparation of polymerization catalyst” were continuously supplied. Furthermore, triisobutylaluminum was also supplied continuously as a promoting catalyst to make the concentration thereof to 0.93 mmol/kg in hexane. The polymerization temperature was controlled to 85° C. The obtained high-density polyethylene ((A)-2) had an MFR of 3.0 g/10 min and a density of 945 kg/m.sup.3. The evaluation results of the basic characteristics of (A)-2 are shown in Table 1.

(37) (A)-3: The following commercially available product was used.

(38) Brand name Nipolon Hard 5700 manufactured by Tosoh Corporation (MFR 1.0 g/10 min, density 954 kg/m.sup.3).

(39) The evaluation results of the basic characteristics of (A)-3 are shown in Table 1.

(40) TABLE-US-00001 TABLE 1 High-density polyethylene Units (A)-1 (A)-2 (A)-3 MFR g/10 min 1.0 3.0 1.0 Density kg/m.sup.3 952 945 954 Mw/Mn — 2.8 2.6 5.4 Ignition residue Wt % 0.008 0.011 0.025
(2) Linear Low-Density Polyethylene
(B1)-1
[Preparation of Modified Clay]

(41) In 1,500 mL of water, 30 mL of 37% hydrochloric acid and 106 g of N,N-dimethyl-behenylamine were added, and an N,N-dimethyl-behenyl ammonium hydrochloride aqueous solution was prepared. 300 g of montmorillonite having an average particle size of 7.8 μm (prepared by crushing brand name Kunipia F manufactured by Kunimine Industries Co., Ltd. with a crusher) was added to the above hydrochloride aqueous solution, and reacted for 6 hr. After the reaction ended, the reaction solution was filtered and the obtained cake was dried under reduced pressure for 6 hr, and 370 g of a modified clay compound was obtained.

(42) [Preparation of Polymerization Catalyst]

(43) In a 20-L stainless steel container under a nitrogen atmosphere, 3.3 L of heptane, 0.9 L of a heptane solution of triethylaluminum (diluted to 20 wt %), which was equivalent of 1.13 mol of aluminum atoms, and 50 g of the modified clay compound obtained as described above were added, and stirred for 1 hr. To this, diphenylmethylene(4-phenyl-indenyl)(2,7-di-t-butyl-9-fluorenyl)zirconium dichloride was added at the amount equivalent of 1.25 mmol of zirconium atoms, and stirred for 12 hr. A catalyst was prepared by adding 5.8 L of an aliphatic saturated hydrocarbon solvent (brand name IP SOLVENT 2835 manufactured by Idemitsu Petrochemical Co., Ltd.) to the obtained suspension system. (Zirconium concentration 0.125 mmol/L)

(44) [Production of (B1)-1]

(45) Using a tank-type reactor equipped for high-temperature high-pressure polymerization, ethylene and 1-hexene were continuously introduced at an elevated pressure into the reactor, and the total pressure was set to 90 MPa, the 1-hexene concentration to 18 mol %, and the hydrogen concentration to 7 mol %. Then, the reactor was stirred at 1,500 rpm, and the polymerization catalyst obtained as described above was continuously supplied from the supply port of the reactor, and a polymerization reaction was performed while holding the average temperature at 200° C. The obtained linear low-density polyethylene ((B1)-1) had an MFR of 3.5 g/10 min and a density of 910 kg/m.sup.3. The evaluation results of the basic characteristics of (B1)-1 are shown in Table 2.

(46) (B1)-2

(47) [Preparation of Modified Clay]

(48) A modified clay compound was prepared by the same method as (B1)-1.

(49) [Preparation of Polymerization Catalyst]

(50) A polymerization catalyst was prepared by the same method as (B1)-1.

(51) [Production of (B1)-2]

(52) Using a tank-type reactor equipped for high-temperature high-pressure polymerization, ethylene and 1-hexene were continuously introduced at an elevated pressure into the reactor, and the total pressure was set to 90 MPa, the 1-hexene concentration to 18 mol %, and the hydrogen concentration to 5 mol %. Then, the reactor was stirred at 1,500 rpm, and the polymerization catalyst obtained as described above was continuously supplied from the supply port of the reactor, and a polymerization reaction was performed while holding the average temperature at 200° C. The obtained linear low-density polyethylene ((B1)-2) had an MFR of 2.0 g/10 min and a density of 907 kg/m.sup.3. The evaluation results of the basic characteristics of (B1)-2 are shown in Table 2.

(53) (B1)-3

(54) [Preparation of Modified Clay]

(55) A modified clay compound was prepared by the same method as (B1)-1.

(56) [Preparation of Polymerization Catalyst]

(57) A polymerization catalyst was prepared by the same method as (B1)-1.

(58) [Production of (B1)-3]

(59) Using a tank-type reactor equipped for high-temperature high-pressure polymerization, ethylene and 1-hexene were continuously introduced at an elevated pressure into the reactor, and the total pressure was set to 90 MPa, the 1-hexene concentration to 20 mol %, and the hydrogen concentration to 15 mol %. Then, the reactor was stirred at 1,500 rpm, and the polymerization catalyst obtained as described above was continuously supplied from the supply port of the reactor, and a polymerization reaction was performed while holding the average temperature at 200° C. The obtained linear low-density polyethylene ((B1)-3) had an MFR of 12.0 g/10 min and a density of 907 kg/m.sup.3. The evaluation results of the basic characteristics of (B1)-3 are shown in Table 2.

(60) (B1)-4

(61) [Preparation of Modified Clay]

(62) A modified clay compound was prepared by the same method as (B1)-1.

(63) [Preparation of Polymerization Catalyst]

(64) A polymerization catalyst was prepared by the same method as (B1)-1.

(65) [Production of (B1)-4]

(66) Using a tank-type reactor equipped for high-temperature high-pressure polymerization, ethylene and 1-hexene were continuously introduced at an elevated pressure into the reactor, and the total pressure was set to 90 MPa, the 1-hexene concentration to 23 mol %, and the hydrogen concentration to 1 mol %. Then, the reactor was stirred at 1,500 rpm, and the polymerization catalyst obtained as described above was continuously supplied from the supply port of the reactor, and a polymerization reaction was performed while holding the average temperature at 200° C. The obtained linear low-density polyethylene ((B1)-4) had an MFR of 0.8 g/10 min and a density of 900 kg/m.sup.3. The evaluation results of the basic characteristics of (B1)-4 are shown in Table 2.

(67) (B1)-5: The following commercially available product was used. Brand name Nipolon-Z ZF220 manufactured by Tosoh Corporation (MFR 2.0 g/10 min, density 913 kg/m.sup.3).

(68) The evaluation results of the basic characteristics of (B1)-5 are shown in Table 2.

(69) (B2)-1

(70) [Preparation of Modified Clay]

(71) A modified clay compound was prepared by the same method as (B1)-1.

(72) [Preparation of Polymerization Catalyst]

(73) In a 20-L stainless steel container under a nitrogen atmosphere, 2.5 L of heptane, 3.6 L of a heptane solution of triethylaluminum (20 wt % diluted product), which was equivalent of 4.5 mol of aluminum atoms, and 300 g of the modified clay compound obtained as described above were added, and stirred for 1 hr. To this, diphenylmethylene(cyclopentadienyl)(2,7-di-t-butyl-9-fluorenyl)zirconium dichloride, at an amount equivalent of 10 mmol of zirconium atoms, was added, and stirred for 12 hr. A catalyst was prepared by adding 8.7 L of an aliphatic saturated hydrocarbon solvent (brand name IP SOLVENT 2835 manufactured by Idemitsu Petrochemical Co., Ltd.) to the obtained suspension system. (Zirconium concentration 0.67 mmol/L)

(74) [Production of (B2)-1]

(75) Using a tank-type reactor equipped for high-temperature high-pressure polymerization, ethylene and 1-hexene were continuously introduced at an elevated pressure into the reactor, and the total pressure was set to 90 MPa, the 1-hexene concentration to 20 mol %, and the hydrogen concentration to 4 mol %. Then, the reactor was stirred at 1,500 rpm, and the polymerization catalyst obtained as described above was continuously supplied from the supply port of the reactor, and a polymerization reaction was performed while holding the average temperature at 200° C. The obtained linear low-density polyethylene ((B2)-1) had an MFR of 2.5 g/10 min and a density of 921 kg/m.sup.3. The evaluation results of the basic characteristics of (B2)-1 are shown in Table 2.

(76) (B2)-2

(77) [Preparation of Modified Clay]

(78) A modified clay compound was prepared by the same method as (B1)-1.

(79) [Preparation of Polymerization Catalyst]

(80) A polymerization catalyst was prepared by the same method as (B2)-1.

(81) [Production of (B2)-2]

(82) Using a tank-type reactor equipped for high-temperature high-pressure polymerization, ethylene and 1-hexene were continuously introduced at an elevated pressure into the reactor, and the total pressure was set to 90 MPa, the 1-hexene concentration to 10 mol %, and the hydrogen concentration to 5 mol %. Then, the reactor was stirred at 1,500 rpm, and the polymerization catalyst obtained as described above was continuously supplied from the supply port of the reactor, and a polymerization reaction was performed while holding the average temperature at 200° C. The obtained linear low-density polyethylene ((B2)-2) had an MFR of 3.6 g/10 min and a density of 931 kg/m.sup.3. The evaluation results of the basic characteristics of (B2)-2 are shown in Table 2.

(83) (B2)-3

(84) A blend in which the above linear low-density polyethylenes (B2)-1 and (B2)-2 were blended in a 50/50 ratio (parts by weight/parts by weight) was used as (B2)-3. Furthermore, a melt-kneaded product obtained by kneading (B2)-3 under nitrogen flow at 170° C. at a rotation speed of 30 rpm for 15 min using an internal mixer (brand name Labo Plastomill manufactured by Toyo Seiki Seisaku-Sho, Ltd.) had an MFR of 3.1 g/10 min and a density of 926 kg/m.sup.3. The evaluation results of the basic characteristics of this melt-kneaded product are shown in Table 2.

(85) (B2)-4: The following commercially available product was used.

(86) Brand name Nipolon-Z ZF230 manufactured by Tosoh Corporation (MFR 2.0 g/10 min, density 920 kg/m.sup.3).

(87) The evaluation results of the basic characteristics of (B2)-4 are shown in Table 2.

(88) TABLE-US-00002 TABLE 2 Linear low-density polyethylene Units (B1)-1 (B1)-2 (B1)-3 (B1)-4 (B1)-5 MFR g/10 min 3.5 2.0 12.0 0.8 2.0 Density kg/m.sup.3 910 907 907 900 913 Mw/Mn — 2.4 2.2 2.1 2.4 3.5 n-heptane Wt % 0.8 1.0 1.1 1.2 1.5 extraction quantity Linear low-density polyethylene Units (B2)-1 (B2)-2 (B2)-3 (B2)-4 MFR g/10 min 2.5 3.6 3.1 2.0 Density kg/m.sup.3 921 931 926 920 Mw/Mn — 2.0 2.2 2.3 4.6 n-heptane Wt % 0.4 0.2 0.3 1.8 extraction quantity
(3) Ethylene-Based Polymer
(C)-1
[Preparation of Modified Clay]

(89) 300 mL of industrial alcohol (brand name Ekinen F-3 manufactured by Japan Alcohol Trading Co., Ltd.) and 300 mL of distilled water were put in a 1-L flask, and then 17.5 g of concentrated hydrochloric acid and 49.4 g (140 mmol) of dimethylbehenylamine (brand name Amine DM22D manufactured by Lion Corporation) were added. This was heated to 45° C., and after 100 g of synthetic hectorite (brand name Laponite RDS manufactured by Rockwood Additives Ltd.) was dispersed, the mixture was heated to 60° C. and stirred for 1 hr while that temperature was maintained. After the slurry was filter-separated, it was washed twice with 600 mL of 60° C. water and then dried for 12 hr in an 85° C. dryer, and 132 g of organic modified clay was thereby obtained. This organic modified clay was crushed in a jet mill to result in a median size of 15 μm.

(90) [Preparation of Polymerization Catalyst]

(91) A 300-mL flask equipped with a thermometer and a reflux tube was purged with nitrogen, and then 25.0 g of the organic modified clay obtained in “Preparation of modified clay” and 108 mL of hexane were introduced. Then, 0.4406 g of dimethylsilylene(cyclopentadienyl)(2,4,7-trimethylindenyl)zirconium dichloride and 142 mL of 20% triisobutylaluminum were added, and stirred for 3 hr at 60° C. After it was cooled to 45° C., the supernatant was removed and washed five times with 200 mL of hexane, and then 200 mL of hexane was added, and a catalyst suspension (solid content: 12.4 wt %) was obtained.

(92) [Production of (C)-1]

(93) In a 2-L autoclave, 1.2 L of hexane, 1.0 mL of 20% triisobutylaluminum, and 52 mg (equivalent to 6.4 mg of solid content) of the catalyst suspension obtained in “Preparation of polymerization catalyst” were added, and after heating to 70° C., 17.6 g of 1-butene was added, and then ethylene/hydrogen mixed gas was continuously supplied so as to result in a partial pressure of 0.80 MPa (concentration of hydrogen in ethylene/hydrogen mixed gas: 590 ppm). After 90 minutes had elapsed, it was depressurized, and the slurry was filtered and then dried to yield 61.8 g of polymer. The obtained polymer had an MFR of 1.6 g/10 min and a density of 930 kg/m.sup.3. The number-average molecular weight was 17,600, the weight-average molecular weight was 86,700, and peaks were observed at the positions of molecular weight 30,500 and 155,300. The number of long-chain branches per 1,000 carbons of the main chain in the fraction having Mn of not less than 100,000 when fractioned by molecular weight was 0.27. The proportion of the fraction having Mn of not less than 100,000 when fractioned by molecular weight was 20.1 wt % of the entire polymer. The melt tension was 75 mN. The evaluation results are shown in Table 3.

(94) (C)-2

(95) [Preparation of Modified Clay]

(96) 300 mL of industrial alcohol (brand name Ekinen F-3 manufactured by Japan Alcohol Trading Co., Ltd.) and 300 mL of distilled water were put in a 1-L flask, and then 18.8 g of concentrated hydrochloric acid and 49.1 g (120 mmol) of dimethylhexacosylamine (Me.sub.2N(C.sub.26H.sub.53) synthesized by a commonly used method) were added. This was heated to 45° C., and after 100 g of synthetic hectorite (brand name Laponite RDS manufactured by Rockwood Additives Ltd.) was dispersed, the mixture was heated to 60° C. and stirred for 1 hr while that temperature was maintained. After the slurry was filter-separated, it was washed twice with 600 mL of 60° C. water and then dried for 12 hr in an 85° C. dryer, and 140 g of organic modified clay was thereby obtained. This organic modified clay was crushed in a jet mill to result in a median size of 14 μm.

(97) [Preparation of Polymerization Catalyst]

(98) A 300-mL flask equipped with a thermometer and a reflux tube was purged with nitrogen, and then 25.0 g of the organic modified clay obtained in “Preparation of modified clay” and 108 mL of hexane were introduced. Then, 0.4406 g of dimethylsilylene(cyclopentadienyl)(2,4,7-trimethyl-1-indenyl)zirconium dichloride and 142 mL of 20% triisobutylaluminum were added, and stirred for 3 hr at 60° C. After it was cooled to 45° C., the supernatant was removed and washed five times with 200 mL of hexane, and then 200 mL of hexane was added, and a catalyst suspension (solid content: 12.0 wt %) was obtained.

(99) [Production of (C)-2]

(100) In a 2-L autoclave, 1.2 L of hexane, 1.0 mL of 20% triisobutylaluminum, and 75 mg (equivalent to 9.0 mg of solid content) of the catalyst suspension obtained in “Preparation of polymerization catalyst” were added, and after heating to 80° C., 8.3 g of 1-butene was added, and then ethylene/hydrogen mixed gas was continuously supplied so as to result in a partial pressure of 0.85 MPa (concentration of hydrogen in ethylene/hydrogen mixed gas: 850 ppm). After 90 minutes had elapsed, it was depressurized, and the slurry was filtered and then dried to yield 58.5 g of polymer. The obtained polymer had an MFR of 4.0 g/10 min and a density of 941 kg/m.sup.3. The number-average molecular weight was 21,200, the weight-average molecular weight was 74,000, and peaks were observed at the positions of molecular weight 41,500 and 217,100. The number of long-chain branches per 1,000 carbons of the main chain in the fraction having Mn of not less than 100,000 when fractioned by molecular weight was 0.18. The proportion of the fraction having Mn of not less than 100,000 when fractioned by molecular weight was 14.8 wt % of the entire polymer. The melt tension was 49 mN. The evaluation results are shown in Table 3.

(101) (C)-3

(102) [Preparation of Modified Clay]300 mL of industrial alcohol (brand name Ekinen F-3 manufactured by Japan Alcohol Trading Co., Ltd.) and 300 mL of distilled water were put in a 1-L flask, and then 15.0 g of concentrated hydrochloric acid and 42.4 g (120 mmol) of dimethylbehenylamine (brand name Amine DM22D manufactured by Lion Corporation) were added. This was heated to 45° C., and after 100 g of synthetic hectorite (brand name Laponite RDS manufactured by Rockwood Additives Ltd.) was dispersed, the mixture was heated to 60° C. and stirred for 1 hr while that temperature was maintained. After the slurry was filter-separated, it was washed twice with 600 mL of 60° C. water and then dried for 12 hr in an 85° C. dryer, and 122 g of organic modified clay was thereby obtained. This organic modified clay was crushed in a jet mill to result in a median size of 15 μm.
[Preparation of Polymerization Catalyst]

(103) A 300-mL flask equipped with a thermometer and a reflux tube was purged with nitrogen, and then 25.0 g of the organic modified clay obtained in “Preparation of modified clay” and 108 mL of hexane were introduced. Then, 0.4406 g of dimethylsilylene(cyclopentadienyl)(2,4,7-trimethyl-1-indenyl)zirconium dichloride and 142 mL of 20% triisobutylaluminum were added, and stirred for 3 hr at 60° C. After it was cooled to 45° C., the supernatant was removed and washed five times with 200 mL of hexane, and then 200 mL of hexane was added, and a catalyst suspension (solid content: 11.5 wt %) was obtained.

(104) [Production of (C)-3]

(105) In a 2-L autoclave, 1.2 L of hexane, 1.0 mL of 20% triisobutylaluminum, and 70 mg (equivalent to 8.4 mg of solid content) of the catalyst suspension obtained in “Preparation of polymerization catalyst” were added, and after heating to 80° C., 2.4 g of 1-butene was added, and then ethylene/hydrogen mixed gas was continuously supplied so as to result in a partial pressure of 0.90 MPa (concentration of hydrogen in ethylene/hydrogen mixed gas: 720 ppm). After 90 minutes had elapsed, it was depressurized, and the slurry was filtered and then dried to yield 63.0 g of polymer. The obtained polymer had an MFR of 11.5 g/10 min and a density of 954 kg/m.sup.3. The number-average molecular weight was 16,200, the weight-average molecular weight was 58,400, and peaks were observed at the positions of molecular weight 28,200 and 181,000. The number of long-chain branches per 1,000 carbons of the main chain in the fraction having Mn of not less than 100,000 when fractioned by molecular weight was 0.16. The proportion of the fraction having Mn of not less than 100,000 when fractioned by molecular weight was 6.8 wt % of the entire polymer. The melt tension was 38 mN. The evaluation results are shown in Table 3.

(106) (C)-4

(107) [Preparation of Modified Clay]

(108) 300 mL of industrial alcohol (brand name Ekinen F-3 manufactured by Japan Alcohol Trading Co., Ltd.) and 300 mL of distilled water were put in a 1-L flask, and then 20.0 g of concentrated hydrochloric acid and 56.5 g (160 mmol) of dimethylbehenylamine (brand name Amine DM22D manufactured by Lion Corporation) were added. This was heated to 45° C., and after 100 g of synthetic hectorite (brand name Laponite RDS manufactured by Rockwood Additives Ltd.) was dispersed, the mixture was heated to 60° C. and stirred for 1 hr while that temperature was maintained. After the slurry was filter-separated, it was washed twice with 600 mL of 60° C. water and then dried for 12 hr in an 85° C. dryer, and 145 g of organic modified clay was thereby obtained. This organic modified clay was crushed in a jet mill to result in a median size of 15 μm.

(109) [Preparation of Polymerization Catalyst]

(110) A 300-mL flask equipped with a thermometer and a reflux tube was purged with nitrogen, and then 25.0 g of the organic modified clay obtained in (1) and 108 mL of hexane were introduced. Then, 0.4406 g of dimethylsilylene(cyclopentadienyl)(2,4,7-trimethyl-1-indenyl)zirconium dichloride and 142 mL of 20% triisobutylaluminum were added, and stirred for 3 hr at 60° C. After it was cooled to 45° C., the supernatant was removed and washed five times with 200 mL of hexane, and then 200 mL of hexane was added, and a catalyst suspension (solid content: 11.2 wt %) was obtained.

(111) [Production of (C)-4]

(112) In a 2-L autoclave, 1.2 L of hexane, 1.0 mL of 20% triisobutylaluminum, and 74 mg (equivalent to 8.3 mg of solid content) of the catalyst suspension obtained in “Preparation of polymerization catalyst” were added, and after heating to 65° C., 17.5 g of 1-butene was added, and then ethylene/hydrogen mixed gas was continuously supplied so as to result in a partial pressure of 0.75 MPa (concentration of hydrogen in ethylene/hydrogen mixed gas: 570 ppm). After 90 minutes had elapsed, it was depressurized, and the slurry was filtered and then dried to yield 51.5 g of polymer. The obtained polymer had an MFR of 0.8 g/10 min and a density of 928 kg/m.sup.3. The number-average molecular weight was 17,900, the weight-average molecular weight was 99,300, and peaks were observed at the positions of molecular weight 28,100 and 229,100. The number of long-chain branches per 1,000 carbons of the main chain in the fraction having Mn of not less than 100,000 when fractioned by molecular weight was 0.26. The proportion of the fraction having Mn of not less than 100,000 when fractioned by molecular weight was 25.4 wt % of the entire polymer. The melt tension was 90 mN. The evaluation results are shown in Table 3.

(113) (C)-5

(114) [Preparation of Modified Clay]

(115) 300 mL of industrial alcohol (brand name Ekinen F-3 manufactured by Japan Alcohol Trading Co., Ltd.) and 300 mL of distilled water were put in a 1-L flask, and then 15.0 g of concentrated hydrochloric acid and 42.4 g (120 mmol) of dimethylbehenylamine (brand name Amine DM22D manufactured by Lion Corporation) were added. This was heated to 45° C., and after 100 g of synthetic hectorite (brand name Laponite RDS manufactured by Rockwood Additives Ltd.) was dispersed, the mixture was heated to 60° C. and stirred for 1 hr while that temperature was maintained. After the slurry was filter-separated, it was washed twice with 600 mL of 60° C. water and then dried for 12 hr in an 85° C. dryer, and 122 g of organic modified clay was thereby obtained. This organic modified clay was crushed in a jet mill to result in a median size of 15 μm.

(116) [Preparation of Polymerization Catalyst]

(117) A 300-mL flask equipped with a thermometer and a reflux tube was purged with nitrogen, and then 25.0 g of the organic modified clay obtained in “Preparation of modified clay” and 108 mL of hexane were introduced. Then, 0.4406 g of dimethylsilylene(cyclopentadienyl)(2,4,7-trimethyl-1-indenyl)zirconium dichloride and 142 mL of 20% triisobutylaluminum were added, and stirred for 3 hr at 60° C. After it was cooled to 45° C., the supernatant was removed and washed five times with 200 mL of hexane, and then 200 mL of hexane was added, and a catalyst suspension (solid content: 11.5 wt %) was obtained.

(118) [Production of (C)-5]

(119) In a 2-L autoclave, 1.2 L of hexane, 1.0 mL of 20% triisobutylaluminum, and 90 mg (equivalent to 10.4 mg of solid content) of the catalyst suspension obtained in “Preparation of polymerization catalyst” were added, and after heating to 65° C., 17.5 g of 1-butene was added, and then ethylene/hydrogen mixed gas was continuously supplied so as to result in a partial pressure of 0.75 MPa (concentration of hydrogen in ethylene/hydrogen mixed gas: 550 ppm). After 90 minutes had elapsed, it was depressurized, and the slurry was filtered and then dried to yield 61.4 g of polymer. The obtained polymer had an MFR of 0.08 g/10 min and a density of 926 kg/m.sup.3. The number-average molecular weight was 21,900, the weight-average molecular weight was 127,000, and peaks were observed at the positions of molecular weight 31,300 and 247,800. The number of long-chain branches per 1,000 carbons of the main chain in the fraction having Mn of not less than 100,000 when fractioned by molecular weight was 0.32. The proportion of the fraction having Mn of not less than 100,000 when fractioned by molecular weight was 36.9 wt % of the entire polymer. The melt tension was 140 mN. The evaluation results are shown in Table 3.

(120) (C)-6

(121) [Preparation of Modified Clay]

(122) 300 mL of industrial alcohol (brand name Ekinen F-3 manufactured by Japan Alcohol Trading Co., Ltd.) and 300 mL of distilled water were put in a 1-L flask, and then 15.0 g of concentrated hydrochloric acid and 42.4 g (120 mmol) of dimethylbehenylamine (brand name Amine DM22D manufactured by Lion Corporation) were added. This was heated to 45° C., and after 100 g of synthetic hectorite (brand name Laponite RDS manufactured by Rockwood Additives Ltd.) was dispersed, the mixture was heated to 60° C. and stirred for 1 hr while that temperature was maintained. After the slurry was filter-separated, it was washed twice with 600 mL of 60° C. water and then dried for 12 hr in an 85° C. dryer, and 122 g of organic modified clay was thereby obtained. This organic modified clay was crushed in a jet mill to result in a median size of 15 μm.

(123) [Preparation of Polymerization Catalyst]

(124) A 300-mL flask equipped with a thermometer and a reflux tube was purged with nitrogen, and then 25.0 g of the organic modified clay obtained in “Preparation of modified clay” and 165 mL of hexane were introduced. Then, 0.3485 g of dimethylsilane diyl-bis(cyclopentadienyl)zirconium dichloride and 85 mL of a hexane solution of triethylaluminum (1.18 M) were added, and stirred for 3 hr at 60° C. It was left to stand, and after it had cooled to room temperature, the supernatant was removed and washed twice with 200 mL of a hexane solution of 1% triisobutylaluminum. The washed supernatant was removed, and a hexane solution of 5% triisobutylaluminum was added to make a total of 250 mL. Then, a solution, which was separately prepared by adding 5 mL of a hexane solution of 20% triisobutylaluminum (0.71 M) to a suspension of 0.1165 g of diphenylmethylene(1-dicyclopentadienyl)(2,7-di-tert-butyl-9-fluorenyl)zirconium dichloride in 10 mL of hexane, was added, and stirred for 6 hr at room temperature. It was left to stand, and the supernatant was removed and washed twice with 200 mL of hexane, and then 200 mL of hexane was added, and a catalyst suspension (solid content: 12.0 wt %) was obtained.

(125) [Production of (C)-6]

(126) In a 2-L autoclave, 1.2 L of hexane, 1.0 mL of 20% triisobutylaluminum, and 125 mg (equivalent to 15.0 mg of solid content) of the catalyst suspension obtained in “Preparation of polymerization catalyst” were added, and after heating to 85° C., 2.4 g of 1-butene was added, and then ethylene was continuously supplied so as to result in a partial pressure of 0.90 MPa. After 90 minutes had elapsed, it was depressurized, and the slurry was filtered and then dried to yield 45.0 g of polymer. The obtained polymer had an MFR of 4.4 g/10 min and a density of 951 kg/m.sup.3. The number-average molecular weight was 9,100, the weight-average molecular weight was 77,100, and peaks were observed at the positions of molecular weight 10,400 and 168,400. The number of long-chain branches per 1,000 carbons of the main chain in the fraction having Mn of not less than 100,000 when fractioned by molecular weight was 0.24. The proportion of the fraction having Mn of not less than 100,000 when fractioned by molecular weight was 15.7 wt % of the entire polymer. The melt tension was 210 mN. The evaluation results are shown in Table 3.

(127) (S)-1: The following commercially available product was used.

(128) Brand name Petrosen 219 manufactured by Tosoh Corporation (MFR 3.0 g/10 min, density 934 kg/m.sup.3).

(129) The evaluation results of the basic characteristics of (S)-1 are shown in Table 3.

(130) (S)-2: The following commercially available product was used.

(131) Brand name RS1000 manufactured by Japan Polyolefins Corporation (MFR 0.1 g/10 min, density 953 kg/m.sup.3)

(132) The evaluation results of the basic characteristics of (S)-2 are shown in Table 3.

(133) TABLE-US-00003 TABLE 3 Ethylene-based polymer Units (C)-1 (C)-2 (C)-3 (C)-4 MFR g/10 min 1.6 4.0 11.5 0.8 Density kg/m.sup.3 930 941 954 928 Mn — 17,600 21,200 16,200 17,900 Mw — 86,700 74,000 58,400 99,300 Mw/Mn — 4.9 3.5 3.6 5.6 Molecular weight peak — 30,500 41,500 28,200 28,100 — 155,300 217,100 181,000 229,100 Number of long-chain Per 0.27 0.18 0.16 0.26 branches in 1,000 components having carbons Mn of not less than 100,000 Proportion of Wt % 20.1 14.8 6.8 25.4 components having Mn of not less than 100,000 MS mN 75 49 38 90 Ethylene-based polymer Units (C)-5 (C)-6 (S)-1 (S)-2 MFR g/10 min 0.08 4.4 3.0 0.1 Density kg/m.sup.3 926 951 934 953 Mn — 21,900 9,100 18,300 21,600 Mw — 127,000 77,100 66,600 128,300 Mw/Mn — 5.8 8.5 3.6 6.0 Molecular weight peak — 31,300 10,400 39,800 45,700 — 247,800 168,400 — — Number of long-chain Per 0.32 0.24 5.30 Less branches in 1,000 than components having carbons 0.01 Mn of not less than 100,000 Proportion of Wt % 36.9 15.7 17.8 31.8 components having Mn of not less than 100,000 MS mN 140 210 90 290
B. Laminate and Hermetically Sealed Container

(134) The laminates and medical containers used in the examples and comparative examples were produced and sterilization treatment was performed by the methods described below.

(135) <Production of Laminate and Medical Container>

(136) Using a three-layer water-cooled inflation molder (manufactured by Placo Co., Ltd.), a three-layer film having a film width of 135 mm and a film thickness of 250 μm was molded at a cylinder temperature of 180° C., a water bath temperature of 15° C., and a pulling rate of 4 m/min. The thickness of each layer was outer layer/intermediate layer/inner layer=20 μm/210 μm/20 μm. Then, a sample 195 mm long was cut out from the three-layer film. One edge was heat-sealed to form a bag shape, and then it was filled with 300 mL of ultrapure water while providing 50 mL of head room, to produce a medical container.

(137) <Sterilization Treatment>

(138) The above medical container was sterilized for 20 min at 121° C. using a steam sterilizer (manufactured by Hisaka Works, Ltd.).

(139) Various properties of the laminates and medical containers used in the examples and comparative examples were evaluated by the following methods.

(140) <Molding Stability>

(141) The stability of the film (bubble) during film formation by a three-layer water-cooled inflation molder was observed visually and evaluated.

(142) ◯: Bubble stability is good

(143) ×: Bubble fluctuation is large

(144) <Film Surface Smoothness>

(145) The surface state of the above molded film was observed visually and evaluated.

(146) ◯: Surface smoothness is good

(147) ×: Surface roughness is large

(148) <Film Appearance>

(149) Wrinkling and deformation of the film surface as well as fusion or the like between inner layers after sterilization treatment were observed visually and evaluated. When no wrinkling or deformation was seen, a score of 4 points was given; when slight wrinkling or deformation was seen, a score of 2 points was given; when fusion between inner layers was seen, a score of 1 point was given.

(150) <Transparency>

(151) A test piece measuring 10 mm wide by 50 mm long was cut out from the above three-layer film and from the sterilized medical container, and light transmittance at wavelength 450 nm was measured in purified water using an ultraviolet-visible spectrophotometer (model V-530 manufactured by JASCO Corporation). The measure of a good medical container was 70% or greater light transmittance maintained after sterilization treatment.

(152) <Film Flexibility>

(153) In accordance with JIS K7161, a test piece was punched out from the medical container after sterilization treatment and the 5% elastic modulus was measured using a tensile tester (model Autograph DCS-500 manufactured by Shimadzu Corporation). When the elastic modulus was not greater than 200 MPa, flexibility was considered good, and when greater than 200 MPa, flexibility was considered poor.

(154) ◯: Flexibility is good

(155) ×: Flexibility is poor

(156) <Moisture Permeability>

(157) In accordance with method A of JIS K7129 (the moisture sensor method), the permeability of a test piece cut out from the above medical container after sterilization treatment was measured using a water vapor permeability tester (model L80-5000 manufactured by Lyssy). The measure of a medical container having good barrier properties was permeability of not greater than 1.0 g (m.sup.2.Math.24 h).

(158) <Cleanliness (Fine Particle Count)>

(159) A medical container produced by the method described in “Production of medical container” above was filled with ultrapure water, which had been confirmed to contain zero fine particles 1 μm or greater per 10 mL, and after it was hermetically sealed, hot-water sterilization treatment was performed for 20 min at 121° C. After letting it stand for 1 day, the number of fine particles 1 μm or greater was measured using a fine particle counter model M-3000•4100•HR-60HA manufactured by HIAC/ROYCO. Note that these operations were all performed in a class 1000 clean room. The measure of a medical container with good cleanliness was a fine particle count of not greater than 10 particles per mL.

Example 1

(160) Using the resin compositions shown in Tables 4 and 5, three-layer films were molded using a water-cooled inflation molder, and molding stability, film surface smoothness, and transparency were evaluated. Then, the obtained films were heat-sealed and made into medical containers filled with ultrapure water. High-pressure steam sterilization treatment was performed at 121° C., and the film appearance, transparency, flexibility, permeability, and cleanliness after sterilization treatment were evaluated. The results are shown in Table 6.

Examples 2 to 10, Comparative Examples 1 to 10

(161) Three-layer films and medical containers were produced and evaluated in the same manner as Example 1 except that the resin compositions used in each layer were modified as shown in Tables 4 and 5. The results are shown in Tables 6 and 7.

(162) TABLE-US-00004 TABLE 4 Resin composition for inner and outer layers X-1 X-2 X-3 X-4 X-5 X-6 X-7 High-density Resin no. (A)-1 (A)-2 (A)-1 (A)-2 (A)-2 (A)-1 (A)-2 apolyethylene Density 952 946 952 945 945 952 945 (A) MFR 1.0 3.0 1.0 3.0 3.0 1.0 3.0 Linear low-density Resin no. (B1)-1 (B1)-2 — (B1)-4 (B2)-1 (B1)-4 (B1)-2 polyethylene (B1) Density 910 907 — 900 921 900 907 MFR 3.5 2.0 — 0.8 2.5 0.8 2.0 Ethylene-based Resin no. (C)-1 (C)-2 (C)-1 (C)-3 (C)-1 (C)-2 (C)-1 polymer (C) Density 930 941 930 954 930 941 930 MFR 1.6 4.0 1.6 11.5 1.6 4.0 1.6 Composition Wt % 45/40/15 30/30/40 75/0/25 60/30/10 30/40/30 25/30/45 85/10/5 (A)/(B)/(C) Resin composition for inner and outer layers X-8 X-9 X-10 X-11 X-12 X-13 X-14 High-density Resin no. (A)-1 (A)-1 (A)-2 (A)-3 (A)-2 (A)-1 (A)-2 apolyethylene Density 952 952 945 954 945 952 945 (A) MFR 1.0 1.0 3.0 1.0 3.0 1.0 3.0 Linear low-density Resin no. (B1)-1 (B1)-1 (B1)-4 (B1)-2 (B1)-5 (B1)-1 (B1)-1 polyethylene (B1) Density 910 910 900 907 913 910 910 MFR 3.5 3.5 0.8 2.0 2.0 3.5 3.5 Ethylene-based Resin no. (C)-4 (C)-5 (C)-6 (C)-1 (C)-2 (S)-1 (S)-2 polymer (C) Density 928 926 951 930 941 934 953 MFR 0.80 0.80 4.40 1.6 4.0 3.00 0.10 Composition Wt % 30/30/40 30/30/40 60/30/10 30/40/30 30/30/40 30/30/40 30/40/30 (A)/(B)/(C)

(163) TABLE-US-00005 TABLE 5 Resin composition for intermediate layer Y-1 Y-2 Y-3 Y-4 Y-5 High-density Resin no. (A)-1 (A)-2 (A)-1 (A)-1 (A)-2 polyethylene Density 952 945 952 952 945 (A) MFR 1.0 3.0 1.0 1.0 3.0 Linear low- Resin no. (B1)-2 (B1)-4 (B1)-1 (B1)-4 (B1)-2 density Density 907 900 910 900 907 polyethylene MFR 2.0 0.8 3.5 0.8 2.0 (B1) (A)/(B) wt % 20/80 40/60 15/85 30/70 25/75 Linear low- Resin no. — — — (B2)-2 (B2)-1 density Density — — — 931 921 polyethylene MFR — — — 3.6 2.5 (B2) [(A) − (B1)]/ Parts by 100/0 100/0 100/0 100/20 100/10 (B2) weight Resin composition for intermediate layer Y-6 Y-7 Y-8 Y-9 High-density Resin no. (A)-1 (A)-2 (A)-1 (A)-2 polyethylene Density 952 945 952 945 (A) MFR 1.0 3.0 1.0 3.0 Linear low- Resin no. (B1)-2 (B1)-2 (B1)-2 (B2)-1 density Density 907 907 907 921 polyethylene MFR 2.0 2.0 2.0 2.5 (B1) (A)/(B) wt % 20/80 20/80 50/50 20/80 Linear low- Resin no. (B2)-3 (B2)-4 — — density Density 926 920 — — polyethylene MFR 3.0 2.0 — — (B2) [(A) − (B1)]/ Parts by 100/25 100/10 100/0 100/0 (B2) weight

(164) TABLE-US-00006 TABLE 6 Example Example Example Example Example Units 1 2 3 4 5 Resin Outer layer — X-1 X-2 X-3 X-4 X-2 composition Intermediate layer — Y-1 Y-2 Y-3 Y-2 Y-4 Inner layer — X-1 X-1 X-1 X-2 X-2 Film Molding stability — ∘ ∘ ∘ ∘ ∘ properties Surface smoothness — ∘ ∘ ∘ ∘ ∘ Appearance after — 4 4 4 4 4 sterilization treatment Transparency Before % 88 86 83 85 86 sterilization treatment After % 82 81 78 80 81 sterilization treatment Flexibility — ∘ ∘ ∘ ∘ ∘ Moisture permeability g/(m.sup.2 .Math. 24 h) 0.9 0.7 0.9 0.7 0.6 Cleanliness per mL 7 8 7 8 8 Example Example Example Example Example Units 6 7 8 9 10 Resin Outer layer — X-1 X-3 X-4 X-11 X-12 composition Intermediate layer — Y-5 Y-6 Y-7 Y-1 Y-1 Inner layer — X-1 X-4 X-3 X-1 X-1 Film Molding stability — ∘ ∘ ∘ ∘ ∘ properties Surface smoothness — ∘ ∘ ∘ ∘ ∘ Appearance after — 4 4 4 4 4 sterilization treatment Transparency Before % 87 85 83 87 85 sterilization treatment After % 80 78 76 79 74 sterilization treatment Flexibility — ∘ ∘ ∘ ∘ ∘ Moisture permeability g/(m.sup.2 .Math. 24 h) 0.8 0.7 0.8 0.8 1.0 Cleanliness per mL 8 9 10 7 8

(165) TABLE-US-00007 TABLE 7 Comparative Comparative Comparative Comparative Comparative Units Example 1 Example 2 Example 3 Example 4 Example 5 Resin Outer layer — X-5 X-6 X-2 X-8 X-9 composition Intermediate layer — Y-1 Y-1 Y-1 Y-1 Y-1 Inner layer — X-5 X-1 X-7 X-1 X-1 Film Molding stability — ∘ ∘ ∘ ∘ ∘ properties Surface smoothness — ∘ x ∘ ∘ x Appearance after — 4 3 4 3 2 sterilization treatment Transparency Before % 80 84 83 87 85 sterilization treatment After % 72 78 76 75 69 sterilization Flexibility — x ∘ x ∘ ∘ Moisture permeability g/(m.sup.2 .Math. 24 h) 0.9 0.8 0.6 1.1 0.8 Cleanliness per mL 7 7 6 8 7 Comparative Comparative Comparative Comparative Comparative Units Example 6 Example 7 Example 8 Example 9 Example 10 Resin Outer layer — X-1 X-13 X-14 X-1 X-1 composition Intermediate layer — Y-1 Y-1 Y-1 Y-8 Y-9 Inner layer — X-10 X-13 X-14 X-1 X-1 Film Molding stability — ∘ ∘ x ∘ ∘ properties Surface smoothness — ∘ x x ∘ ∘ Appearance after — 4 4 4 4 4 sterilization treatment Transparency Before % 86 86 84 72 75 sterilization treatment After % 79 75 72 53 56 sterilization Flexibility — ∘ ∘ x x x Moisture permeability g/(m.sup.2 .Math. 24 h) 0.9 1.2 1.0 0.5 0.6 Cleanliness per mL 12 13 11 8 7

(166) The present invention has been described in detail with reference to specific embodiments, but, it is obvious for a person skilled in the art that various changes and modifications are possible without departing from the intention and the scope of the present invention.

(167) All of the content of the specifications, scopes of patent claims, drawings, and abstracts of Japanese Patent Application No. 2013-213046 filed on Oct. 10, 2013 is cited here and incorporated as a disclosure of the specification of the present invention.