JP3373586B2 - Multilayer squeezed tubular cylindrical container - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a squeezed tubular cylindrical container, and more specifically, it is composed of a crosslinked polyethylene layer and an oxygen barrier resin layer and is excellent in flexibility and oxygen barrier property and has a temperature of 121 ° C. The present invention relates to a squeezed tubular cylindrical container capable of high temperature sterilization treatment for about 30 minutes.

[0002]

2. Description of the Related Art As the materials used for packaging containers are being reformed, many containers, such as retort containers, which are required to have a characteristic capable of withstanding sterilization at a high temperature for a relatively long time have been proposed. Of these, usually, a thermoplastic resin simple substance such as high heat-resistant polypropylene or high-density polyethylene, or a saponified ethylene-vinyl acetate copolymer, or an oxygen barrier resin layer made of nylon or the like is used as an intermediate layer. A laminate of olefin resin layers such as polypropylene or high-density polyethylene on both sides is used. However, these containers have a high elastic modulus and are not always suitable as a squeezed tubular cylindrical container that requires flexibility, and although low density polyethylene has excellent flexibility, it has a large shrinkage ratio and is subjected to high temperature sterilization treatment. When attached to, it has the drawback of shrinking,
It is not suitable as a material for squeezed tubular cylindrical containers for retort sterilization.

[0003]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention A squeezable tubular tubular container capable of high temperature sterilization is a thermoplastic resin simple substance such as polypropylene or high density polyethylene having high heat resistance, or an ethylene-vinyl acetate copolymer, as described above. An oxygen barrier resin layer made of saponified material or nylon is used as an intermediate layer, and an olefin resin layer such as polypropylene or high-density polyethylene is laminated on both sides of this layer. It is unsatisfactory as a tubular cylindrical container that has a high rate and needs flexibility.

The present inventors have, on the basis of the recognition of the prior art, a squeezed tubular cylinder made of a composition of polyethylene and ethylene-α-olefin copolymer having a density of 0.900 to 0.975 g / cm ^3. By irradiating the container with an electron beam, it was found that a tubular cylindrical container having a small shrinkage rate and flexibility can be obtained even by sterilization treatment at high temperature, and a patent application was filed as Japanese Patent Application No. 4-287906. .

The present inventors repeated the above-mentioned invention of the prior application and conducted further research to obtain a tubular cylindrical container having excellent physical properties. As a result, polyethylene used as one component of the material of the container in the invention of the earlier application. A part or all of which is graft-modified with an unsaturated carboxylic acid or a derivative thereof is used as the inner and outer layers, and an oxygen barrier resin layer is disposed in the middle between the layers, whereby the high temperature The present invention has been completed based on the finding that a squeezed tubular cylindrical container having an excellent oxygen barrier property in addition to the features of low shrinkage and excellent flexibility was obtained.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a multilayer squeezed tubular cylindrical container which has a small shrinkage factor due to heat even when subjected to high temperature sterilization, has excellent flexibility, and has an excellent oxygen barrier property. To do.

[0007]

DISCLOSURE OF THE INVENTION The present invention has been proposed in order to achieve the above-mentioned object, and uses a laminate composed of a specific polymer composition as a raw material of a squeezed tubular cylindrical container, It is characterized in that the irradiation processing is performed with a line. That is, according to the present invention,
(1) Partially or wholly graft-modified with unsaturated carboxylic acid or its derivative has a density of 0.900 g / cm
³ to the inner and outer layers comprising the composition of polyethylene and ethylene -α- olefin copolymer of 0.975g / cm ^3, (2) oxygen consisting barrier resin intermediate layer and the heat-resistant squeeze tube shape and a There is provided a squeezed tubular cylindrical container capable of high temperature sterilization, which is characterized in that a cylindrical container is irradiated with an electron beam.

The blending ratio of the ethylene-α-olefin copolymer to polyethylene in the inner and outer layers is in the range of 5 to 50% by weight, and particularly 10 to 4
The range of 0% is preferable. Furthermore, the absorbed dose of electron beam is
50 to 500 kGy, especially 100 to 300 k
Gy is preferable in order to obtain a squeezed tubular cylindrical container having a small shrinkage factor due to heat even when subjected to high temperature sterilization treatment and having excellent flexibility, which is an object of the present invention.

[0009]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in more detail. The most technical feature of the present invention is that a part or all of which is graft-modified with an unsaturated carboxylic acid or a derivative thereof (hereinafter sometimes simply referred to as “graft monomer”) and has a density of 0.900 g / cm ^3. To 0.975g
The purpose is to irradiate an electron beam on a squeezed tubular cylindrical container formed of an inner / outer layer made of a polyethylene / cm ³ composition of ethylene / α-olefin copolymer and an intermediate layer made of an oxygen barrier resin.

The density which is partially or wholly graft-modified with an unsaturated carboxylic acid or a derivative thereof is 0.900.
and polyethylene g / cm ³ to 0.975 g / cm ^3, a density of less than 0.900 g / cm ³ ethylene -α-
The blending ratio of the olefin copolymer is 50 to 95% by weight / 5 to 50% by weight, particularly 60 to 90% by weight.
It is preferably / 10 to 40% by weight.

The polyethylene used in the present invention has a density of 0.900 g / cm ³ to 0.975 g / cm ³ , preferably 0.920 to 0.975 g / cm ³ , and particularly preferably 0.935 to 0.970 g. / Cm ³ , melt flow rate (MFR) (ASTM D 1238
190 ° C.) is 0.01 to 10, preferably 0.1
To 5 homopolymers of ethylene or copolymers of ethylene with other α-olefins such as propylene and 1-butene.

Examples of the unsaturated carboxylic acid or its derivative include acrylic acid, methacrylic acid, α-ethylacrylic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, tetrahydrophthalic acid, methyltetrahydrophthalic acid, endocis- Bicyclo [2.2.1] hept-5-ene-2,3-dicarboxylic acid (nadic acid)
Etc. and their derivatives such as acid halides, amides, imides, acid anhydrides and esters. Of these, unsaturated dicarboxylic acids or acid anhydrides thereof are preferable, and maleic acid, nadic acid, or acid anhydrides thereof are particularly preferable.

The unsaturated carboxylic acid or its derivative is
Density is 0.900 g / cm ³ to 0.975 g / cm
^As the method of grafting to the polyethylene of ³ , various known methods can be adopted. For example, it is carried out by heating the ethylene polymer and the graft monomer to a high temperature in the presence or absence of a solvent, with or without the addition of a radical initiator. In the reaction,
Other vinyl monomers such as styrene may coexist.

The amount of grafting of the above-mentioned grafting monomer onto polyethylene (grafting rate) is preferably adjusted to 0.001 to 10% by weight, particularly 0.01 to 1% by weight. The polyethylene of the present invention may be partially or wholly grafted, but from the industrial viewpoint, a modified polyethylene having a graft ratio of about 0.1 to 10% by weight is produced in advance. However, it is preferable to mix the modified polyethylene with the unmodified polyethylene in order to adjust the concentration of the graft monomer in the polyethylene.

The density obtained by graft-modifying a part or all of the above with an unsaturated carboxylic acid or a derivative thereof is 0.9.
The inner and outer layers composed of a composition of polyethylene and ethylene-α-olefin copolymer of 00 g / cm ³ to 0.975 g / cm ³ and the intermediate layer composed of a gas barrier resin are known per se using a screw extruder or the like. Is coextruded by the molding method described above to form a tubular cylindrical container.

In the structure of the tubular cylindrical container of the present invention, it is important that the layers (A) / (B) are formed adjacent to each other, and the outermost layer thereof has an unmodified density of 0. .900 g / cm ³ to 0.975 g / c
A composition layer (C) of m ³ of polyethylene and an ethylene-α-olefin copolymer may be provided. In addition, the resin of the innermost layer of the tube is (A) /
As long as the (B) / (A) configuration is included, a density of 0.90
You may use the polyethylene component (D) which is 0 to 0.975 g / cm < ³ >.

That is, as a layer structure of the tubular cylindrical container embodying the present invention, each layer is composed of, for example, (A) /
(B) / (A), (C) / (A) / (B) / (A),
(C) / (A) / (B) / (A) / (C), (A) /
(B) / (A) / (D), (C) / (A) / (B) /
(A) / (D), (C) / (A) / (B) / (A) /
(C) / (D) and the like.

In the present invention, it is an important feature to irradiate the tubular cylindrical container having the above structure with an electron beam. The electron beam irradiation is carried out using an electron beam irradiation device known per se, at 50 to 500 kGy, preferably 10
Irradiation with 0 to 300 kGy, whereby polyethylene and ethylene-α-olefin copolymer, which are components of the above composition, are cross-linked, resulting in a gel fraction of 40% or more, resulting in hot water. The free shrinkage (shrinkage when the sample was placed in an autoclave and heat-treated at 121 ° C. for 30 minutes) was set to 3% or less, and the high temperature sterilization treatment was performed without impairing the flexibility originally possessed by the composition. It is possible to provide a squeezed tubular cylindrical container which is possible and has an excellent oxygen barrier property.

However, depending on the amount of electron beam irradiation, polyethylene and ethylene-α-olefin copolymer, which are components of the composition, are crosslinked, and the molecules in the composition have a three-dimensional network structure. That is, a so-called gel state is reached, and it becomes difficult to melt at a temperature equal to or higher than the melting point. Therefore, the sealing property of the composition may be impaired. In that case, by irradiating only the sealed part with irradiation, high-temperature sterilization treatment is possible without impairing the sealing property and having the original flexibility of the composition, and the oxygen barrier property. An excellent squeezed tubular cylindrical container is provided.

The density of the high density polyethylene graft-modified with an unsaturated carboxylic acid or a derivative thereof partially or wholly is 0.900 g / cm ³ to 0.975 g.
/ Cm ³ , preferably 0.930 g / cm ³ to 0.
975 g / cm ³ is preferable, and melt flow rate (M
FR) is 0.01 g / 10 min to 10 g / 10
Min, particularly 0.1 to 5 is preferably used.

As the ethylene / α-olefin copolymer, a low crystalline or amorphous ethylene / α-olefin copolymer is preferably used, and its density is 0.850.
g / cm ³ to 0.900 g / cm ³ , especially 0.86
0 to 0.895 is preferable, and the melt flow rate (MFR) is 0.1 g / 10 min to 10 g / 1.
0 min, especially 0.2 to 5 is preferably used.

The α-olefin copolymerized with ethylene includes propylene, butene-1, pentene-1, 4-.
Methylpentene-1, hexene-1, octene-1, decene-1 and the like can be exemplified, but above all, propylene and butene-1 are preferably used as comonomer components.

In the ethylene-α-olefin copolymer, the molar ratio of ethylene and α-olefin is ethylene / α-olefin = 95/5 to 70/30,
It is particularly preferably 90/10 to 75/25.

The oxygen barrier layer constituting the intermediate layer of the squeezed tubular cylindrical container of the present invention is nylon,
A saponified ethylene-vinyl acetate copolymer is preferably used. As nylon, nylon 6 and nylon 6-
6, long-chain synthetic polyamides having a repeating amide group as an integral part of the polymer main chain, such as 6, nylon 6-10, nylon 11 and nylon 12.

As the saponified product of the ethylene-vinyl acetate copolymer, an ethylene-vinyl acetate copolymer having an ethylene content of 26 to 65 mol% is saponified by a method known per se, and the saponification degree is 96% or more, preferably. Is 99% or more. Those having an ethylene content and a saponification degree within the above ranges are excellent not only in oxygen barrier properties but also in physical properties such as mechanical properties, oil resistance, and water resistance, and are preferably used for the purpose of the present invention. .

Examples of the method for laminating the multilayer tubular cylindrical container of the present invention include a method of co-extruding the resin component forming each layer from an extruder or extrusion coating. The tubular body of the present invention is obtained by cutting the tubular body extruded by these methods to an appropriate length, heat-sealing one end of the tubular body, and fusion-bonding the other preformed mouth to the mouth. A cylindrical container is obtained.

The thickness of each layer constituting the squeezed tubular cylindrical container of the present invention is 50 μ to 300 μ for the outer layer, 5 μ to 150 μ for the intermediate layer, and 50 μ to 300 for the inner layer.
μ, particularly 100 μ to 200 μ for the outer layer and 30 for the intermediate layer
It is preferable that the total thickness is 380 μ to 500 μ with μ to 75 μ and the inner layer is 200 μ to 300 μ.

The polymer composition constituting the squeezed tubular cylindrical container of the present invention contains a filler, a stabilizer, a lubricant, an antistatic agent, a flame retardant, and a flame retardant within a range not impairing the object of the present invention.
Additives known per se such as a foaming agent can be blended.

[0029]

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples as long as the gist thereof is not exceeded. Incidentally, of the physical properties of the multilayer squeezed tubular cylindrical container obtained by the example, the drag is an index for evaluating the flexibility of the container, the load on the tubular surface from above the tubular portion of the tubular cylindrical container ( It means the stress when the tubular cylinder is compressed into an elliptic cylinder with a short diameter of 10 mm at a compression speed of 100 mm / min), and the drag force is preferably 1.5 kgf or less. Be evaluated as a thing.

The oxygen barrier performance required for a container for packaging general food depends on the oxygen acceptor concentration of the food and the shelf life. 40m inner diameter of foods with an allowable oxygen concentration of 5ppm
When packed in a tubular cylindrical container having a length of m and a length of 150 mm, the oxygen permeation rate of the container is 0.003 cc / da.
A value of y or less is evaluated as having a desired oxygen barrier performance. For the measurement, for example, MOCO
OX-TRAN (10/50) manufactured by N company is used, and 2
It is performed in a room where the temperature and humidity are controlled at 3 ° C and 55% Rh.

The hot water free shrinkage ratio is the shrinkage ratio after the sample is placed in an autoclave and treated at 121 ° C. for 30 minutes, and it is evaluated that the heat resistance is preferably 3% or less. -Gel fraction is the residual weight% after boiling the sample after removing the oxygen barrier resin with xylene for 24 hours,
It is an index for evaluating chemical resistance, and 40% or more is evaluated as having preferable chemical resistance.

Example 1 Each layer having the structure shown below was coextruded under the following conditions to form a tubular cylindrical container. <Outer layer > Modified medium density polyethylene having a density of 0.938 g / cm ³ grafted with 0.17 wt% of maleic anhydride and an ethylene-propylene copolymer (ethylene content 80 mol%) in a ratio of 70:30. The composition (A) (the density of this polymer composition was 0.916 g / cm ³ ) was extruded at 190 ° C. using a screw having a diameter of 40 mm and an effective length of 1000 mm. <Intermediate layer> Eval (registered trademark) EP-F (MFR1.3) (B) manufactured by Kuraray Co., Ltd. as an oxygen barrier resin has a diameter of 30 m.
m, using a screw with an effective length of 750 mm, 225 ° C
Extruded. <Inner layer > A modified medium density polyethylene having a density of 0.938 g / cm ³ grafted with maleic anhydride 0.17 wt% and an ethylene-propylene copolymer (ethylene content 80 mol%) were mixed at a ratio of 70:30. The composition (A) (the density of this polymer composition was 0.916 g / cm ³ ) was extruded at 160 ° C. using a screw having a diameter of 50 mm and an effective length of 1200 mm. The die temperature was 230 ° C., and the molding speed was 6 m / min. In this way
The thickness of each layer is outer layer / middle layer / inner layer = 150/50/2
A tubular cylindrical container having a diameter of 50 μm, an inner diameter of 40 mm and a length of 150 mm was obtained. This tube-shaped cylindrical container was irradiated with an electron beam at 200 kGY, and the hot water free shrinkage rate, gel fraction, drag, oxygen permeation rate, and the same container were filled with water.
Table 1 shows changes in the appearance of the container when subjected to a high temperature sterilization treatment at 0 ° C for 30 minutes.

Example 2 Each layer having the structure shown below was coextruded under the following conditions to form a tubular cylindrical container. <Outer layer > A composition (C) in which a medium density polyethylene having a density of 0.938 g / cm ³ , a melting point of 125 ° C. and an ethylene-propylene copolymer (ethylene content 80 mol%) were blended at a ratio of 70:30 (this). The density of the polymer composition is 0.
916 g / cm ³ ), diameter 50 mm, effective length 120
It was extruded at 190 ° C. using a 0 mm screw. <Adhesive layer 1> 70:30 ratio of a modified medium density polyethylene having a density of 0.938 g / cm ³ grafted with maleic anhydride 0.17 wt% and an ethylene-propylene copolymer (ethylene content 80 mol%). (A) compounded in (the density of this polymer composition is 0.916 g / c
m ³ ) was extruded at 190 ° C. using a screw having a diameter of 40 mm and an effective length of 1000 mm. <Intermediate layer> Eval (registered trademark) EP-F (MFR1.3) (B) manufactured by Kuraray Co., Ltd. as an oxygen barrier resin
Was extruded at 225 ° C. using a screw having a diameter of 30 mm and an effective length of 750 mm. <Adhesion layer 2> 70:30 ratio of a modified medium density polyethylene having a density of 0.938 g / cm ³ grafted with maleic anhydride 0.17 wt% and an ethylene-propylene copolymer (ethylene content 80 mol%). (A) compounded in (the density of this polymer composition is 0.916 g / c
m ³ ) was extruded at 190 ° C. using a screw having a diameter of 40 mm and an effective length of 1000 mm. <Inner layer > A composition (C) in which a medium density polyethylene having a density of 0.938 g / cm ³ , a melting point of 125 ° C. and an ethylene-propylene copolymer (ethylene content 80 mol%) were mixed in a ratio of 70:30 (this). The density of the polymer composition is 0.
916 g / cm ³ ), diameter 50 mm, effective length 120
It was extruded at 190 ° C. using a 0 mm screw. In this way, the thickness of each layer is as follows: outer layer / adhesive layer 1 / intermediate layer /
Adhesive layer 2 / inner layer = 130/20/50/20 / 230μ
A tubular cylindrical container having an inner diameter of 40 mm and a length of 150 mm was obtained. 20
Hot water free shrinkage ratio, gel fraction, drag force, oxygen permeation amount of a sample irradiated with 0KGy, and water was filled in the same container at 120 ° C-
Table 1 shows the changes in the appearance of the container after the high temperature sterilization treatment for 30 minutes.

<Comparative Example 1> Each layer having the structure shown below was coextruded under the following conditions to form a tubular cylindrical container. <Outer layer > Modified medium density polyethylene having a density of 0.938 g / cm ³ grafted with 0.17 wt% of maleic anhydride and an ethylene-propylene copolymer (ethylene content 8
0 mol%) in a proportion of 70:30 (A)
(The density of this polymer composition is 0.916 g / cm ³ ).
Was extruded at 190 ° C. using a screw having a diameter of 40 mm and an effective length of 1000 mm. <Intermediate layer> As the oxygen barrier resin, EVAL (registered trademark) EP-F (MFR1.3) (B) manufactured by Kuraray Co., Ltd. was extruded at 225 ° C using a screw having a diameter of 30 mm and an effective length of 750 mm. <Inner layer > Modified medium density polyethylene having a density of 0.938 g / cm ³ grafted with 0.17 wt% of maleic anhydride and an ethylene-propylene copolymer (ethylene content 8
0 mol%) in a proportion of 70:30 (A)
(The density of this polymer composition is 0.916 g / cm ³ ).
Was extruded at 160 ° C. using a screw having a diameter of 50 mm and an effective length of 1200 mm. The die temperature was 230 ° C., and the molding speed was 6 m / min. In this way, the thickness of each layer is as follows: outer layer / middle layer / inner layer = 150/50
A tubular cylindrical container having an inner diameter of 40 mm and a length of 150 mm was obtained. Table 1 shows the free shrinkage rate of hot water, gel fraction, drag force, oxygen permeation amount of this tubular cylindrical container and appearance change of the container when the container was filled with water and subjected to a high temperature sterilization treatment at 120 ° C. for 30 minutes. Indicated.

<Comparative Example 2> Each layer having the constitution shown below was coextruded under the following conditions to form a tubular cylindrical container. < Outer layer > A modified low-density polyethylene having a density of 0.92 g / cm ³ grafted with maleic anhydride 0.15 wt% was used with a screw having a diameter of 40 mm and an effective length of 1000 mm.
Extruded at 190 ° C. <Intermediate layer> Eval (registered trademark) EP-F (MFR1.3) manufactured by Kuraray Co., Ltd. as an oxygen barrier resin, having a diameter of 30 mm,
Extrusion was carried out at 225 ° C using a screw having an effective length of 750 mm. <Inner layer > Modified low density polyethylene having a density of 0.91 g / cm ³ grafted with maleic anhydride 0.15 wt% was used with a screw having a diameter of 50 mm and an effective length of 1200 mm.
Extruded at 160 ° C. In this way, the thickness of each layer is
Outer layer / middle layer / inner layer = 150/50 / 250μ,
A tubular cylindrical container having an inner diameter of 40 mm and a length of 150 mm was obtained. An electron beam of 200 kGY is applied to this tubular cylindrical container.
Table 1 shows the hot water free shrinkage ratio, gel fraction, drag force, oxygen permeation amount of the irradiated sample, and appearance change of the container when the container was filled with water and subjected to high temperature sterilization treatment at 120 ° C. for 30 minutes. .

Comparative Example 3 Each layer having the constitution shown below was coextruded under the following conditions to form a tubular cylindrical container. < Outer layer > A modified low-density polyethylene having a density of 0.92 g / cm ³ grafted with maleic anhydride 0.15 wt% was used with a screw having a diameter of 40 mm and an effective length of 1000 mm.
Extruded at 190 ° C. <Intermediate layer> Nylon having a diameter of 30 mm as an oxygen barrier resin,
Extrusion was carried out at 215 ° C. using a screw having an effective length of 750 mm. <Inner layer > Modified low density polyethylene having a density of 0.91 g / cm ³ grafted with maleic anhydride 0.15 wt% was used with a screw having a diameter of 50 mm and an effective length of 1200 mm.
Extruded at 160 ° C. In this way, the thickness of each layer is
Outer layer / middle layer / inner layer = 150/50 / 250μ,
A tubular cylindrical container having an inner diameter of 40 mm and a length of 150 mm was obtained. An electron beam of 200 kGY is applied to this tubular cylindrical container.
Table 1 shows the hot water free shrinkage ratio, gel fraction, drag force, oxygen permeation amount of the irradiated sample, and appearance change of the container when the container was filled with water and subjected to high temperature sterilization treatment at 120 ° C. for 30 minutes. .

<Comparative Example 4> Each layer having the structure shown below was coextruded under the following conditions to form a tubular cylindrical container. <Outer layer > A composition (C) in which a medium density polyethylene having a density of 0.938 g / cm ³ , a melting point of 125 ° C. and an ethylene-propylene copolymer (ethylene content 80 mol%) were blended at a ratio of 70:30 (this). The density of the polymer composition is 0.
916 g / cm ³ ), diameter 40 mm, effective length 100
It was extruded at 190 ° C. using a 0 mm screw. <Intermediate layer> Eval (registered trademark) EP-F (MFR1.3) (B) manufactured by Kuraray Co., Ltd. is used as an oxygen barrier resin, using a screw having a diameter of 30 mm and an effective length of 750 mm.
Extruded at 225 ° C. <Inner layer > A composition (C) in which a medium density polyethylene having a density of 0.938 g / cm ³ , a melting point of 125 ° C. and an ethylene-propylene copolymer (ethylene content 80 mol%) were mixed in a ratio of 70:30 (this). The density of the polymer composition is 0.
916 g / cm ³ ), diameter 50 mm, effective length 120
It was extruded at 160 ° C. using a 0 mm screw. In this way, the thickness of each layer is as follows: outer layer / middle layer / inner layer = 15
0/50 / 250μ, inner diameter 40mm, length 150
A tubular cylindrical container of mm was obtained. Since the unmodified polyethylene used for the inner and outer layers of this tubular cylindrical container is non-polar, it does not adhere to the oxygen barrier resin which is the intermediate layer, and the inner layer / intermediate layer delamination strength is 50 g / 15 mm or less, The function as a multilayer tubular cylindrical container was not satisfied.

Table 1 In the table: E is Example R is Comparative Example

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI // C08L 23/26 C08L 23/26 (72) Inventor Fumio Yoshii 1233 Watanuki-cho, Takasaki-shi, Gunma Japan Atomic Energy Research Institute Takasaki Research In-house (72) Hideo Kushida 3-2-6 Oshima, Koshima-ku, Tokyo, Yoshino Industry Co., Ltd. (72) Inventor Shizuka Nakajima 3-26 Oshima, Koto-ku, Tokyo In-house Yoshino Industry (72) Inventor Takahiro Kurihara 350 Takagi, Okanogo, Fujioka, Gunma Prefecture Yoshino Kogyo Co., Ltd. Gunma Factory (72) Inventor Ryoji Sugawara 310 Minorita, Matsudo City, Chiba Prefecture Yoshino Industry Co., Ltd. Matsudo Factory (72) Invention Hideshi Kawauchi 6-1-2 Waki, Waki-cho, Kuga-gun, Yamaguchi Prefecture Mitsui Petrochemical Industry Co., Ltd. (72) Inventor Mikio Nakagawa 6-1, Waki-cho, Kuki-gun, Yamaguchi Prefecture No. 2 in Mitsui Petrochemical Industry Co., Ltd. (56) Reference JP 62-234930 (JP, A) JP 59-95139 (JP, A) JP 61-148250 (JP, A) JP 52-103278 (JP, A) JP-A-3-227346 (JP, A) JP-A-4-27534 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B65D 35 / 08 B32B 27 / 00,27 / 08,27 / 16 B32B 27 / 28,27 / 32 C08J 7/00 C08L 23/26

Claims (4)

(57) [Claims] 1. A (1) partially or fully graft-modified with an unsaturated carboxylic acid or a derivative thereof, and polyethylene to a density 0.900 g / cm ³ without 0.975 g / cm ^3, density of 0.900 g Electron-beam into a heat-resistant squeezed tubular container composed of an inner / outer layer composed of an ethylene-α-olefin copolymer composition of less than 1 / cm ³ and (2) an intermediate layer composed of an oxygen barrier resin. A squeezed tubular cylindrical container capable of high temperature sterilization, which is characterized by irradiating. 2. The blending ratio of ethylene-α-olefin copolymer to polyethylene is 5 to 50 by weight.
The squeezed tubular cylindrical container according to claim 1, which is in the range of%. 3. The absorbed dose of electron beam is 50 to 500.
The squeezed tubular cylindrical container according to claim 1, which is kGy. 4. The squeezed tubular cylindrical container according to claim 1, wherein the oxygen barrier resin layer is a saponified layer of nylon or an ethylene-vinyl acetate copolymer.