JPH08244791A - Retort container - Google Patents

Abstract

PURPOSE: To enhance sanitary properties and transparency and to prevent the generation of wrinkles or deformation by forming at least one layer of a container composed of a single film or a multilayered film from specific straight chain polyethylene. CONSTITUTION: In a container having a layer composed of straight chain polyethylene obtained by copolymerizing ethylene and 3-12C α-olefin, the density of straight chain polyethylene is 0.918-0.940g/cm<3> and the mol. wt. distribution (Mw/Mn: Mw=wt. average mol.wt., Mn= number average mol.wt.) measured by GPC thereof is 1.5-3.0. The layer composed of straight chain polyethylene is characterized by that haze after retort sterilizing treatment is 30% or less and deformation start temp. is higher than sterilizing treatment temp. By this constitution, a container good in sanitary properties and flexibility, not losing transparency even if sterilizing treatment is performed at 115 deg. or higher, excellent in heat resistance and not generating wrinkles or deformation can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a retort container, and more particularly to a medical container for containing blood, liquid medicine, etc., which is excellent in hygiene, flexibility, impact resistance, transparency and heat resistance, and cooking. The present invention relates to a container for retort foods, in which used foods and the like are placed.

[0002]

BACKGROUND OF THE INVENTION As medical containers currently in use, a hard container made of glass, polyethylene, polypropylene or the like and a soft bag made of polyvinyl chloride containing a plasticizer are known. However, the above-mentioned hard container needs to introduce air using a transfusion set with a ventilating needle or a vent when dropping a content liquid such as blood or a drug solution. May be contaminated. On the other hand, the soft bag, unlike the above-mentioned hard container, does not require the introduction of air when dropping the content liquid, and the bag itself is squeezed by the atmospheric pressure along with the dropping of the content liquid, so that hygiene, Convenience of transportation,
There are advantages such as small volume of waste. However, there are problems such as toxicity of plasticizers and residual monomers contained in polyvinyl chloride.

On the other hand, a medical bag using a polymer such as an ethylene / vinyl acetate copolymer or an elastomer as an intermediate layer has been proposed for the purpose of improving flexibility, transparency, hygiene, etc. (Kaisho 58-165866). However, in this medical bag, since the polymer used for the intermediate layer has poor heat resistance, there is a problem that a wrinkle state occurs in the bag during the retort sterilization process. Also, conventional medical bags made from polyethylene have a slightly insufficient heat resistance and cannot raise the sterilization temperature, so the sterilization process takes longer or the sterilization process is performed in a highly clean atmosphere. Inefficiency in the sterilization process, which must be done, is a problem.

Therefore, it has good hygiene and flexibility, does not lose transparency even when sterilized at 115 ° C. or higher as shown in the Japanese Pharmacopoeia, and is excellent in heat resistance, causing wrinkles and deformation. It has been desired to develop a polyethylene medical container that does not become worn, for example, a medical bag made of a multilayer or single layer film and a medical bottle made of a multilayer or single layer.

Generally, a polyolefin resin is used for a sealant film of a food laminate packaging material, and a polypropylene film having a high melting point is often used for retort foods from the viewpoint of heat resistance.

However, in order to realize long-term storage at low temperatures and in cold regions by pouching large-scale commercial containers in recent years, the retort food film is required to have low-temperature impact resistance. At the same time, transparency is required from the viewpoint that it is better to confirm the contents.

The polypropylene film is generally inferior in low temperature impact resistance and therefore cannot satisfy the above requirements. As a film having improved low-temperature impact resistance, there are films of ethylene / propylene block copolymer and the like, but these films are inferior in transparency, and therefore cannot be used in the fields requiring transparency.

On the other hand, the conventional low-density polyethylene film is excellent in low-temperature impact resistance and transparency, and further excellent in low-temperature sealing property, so that it is possible to overcome the drawbacks of the above-mentioned polypropylene film, but it is inferior in heat resistance and sterilized. There is a problem that the temperature cannot be raised. Further, when a composition obtained by blending low-density polyethylene with high-density polyethylene is used, the heat resistance of the obtained film is improved, but the transparency is lowered. Further, this film has a problem that transparency is deteriorated by sterilization treatment (retort treatment).

[0009] Therefore, the appearance of a container for retort foods, which is composed of a single-layer or multi-layer film having at least one polyethylene film layer which has good hygiene properties, excellent transparency, and is free from wrinkles and deformation, is desired. There is.

[0010]

SUMMARY OF THE INVENTION The present invention is intended to solve the problems associated with the prior art as described above, has good hygiene and flexibility, and is transparent even when sterilized at 115 ° C or higher. It is an object of the present invention to provide a polyethylene retort container that is not lost, has excellent heat resistance, and does not wrinkle or deform.

[0011]

SUMMARY OF THE INVENTION A retort container according to the present invention is a container having a layer composed of a linear polyethylene obtained by copolymerizing ethylene and an α-olefin having 3 to 12 carbon atoms. Polyethylene has (i) a density of 0.9
In the range of 18 to 0.940 g / cm ³ , (ii) GP
The molecular weight distribution (Mw / Mn: Mw = weight average molecular weight, Mn = number average molecular weight) measured by C is in the range of 1.5 to 3.0, and the layer made of the linear polyethylene is (a) ) The haze after retort sterilization is 30% or less, and (b) the deformation start temperature (Td [° C]) is higher than the sterilization temperature.

The above linear polyethylene is (iii) 23
When the decane-soluble component fraction (W [wt%]) and the density (d [g / cm ³ ]) at M ° C. are MFR ≦ 10 g / 10 min, W <80 × exp (−100 (d−0) .88)) + 0.1 When MFR> 10 g / 10 minutes, W <80 × (MFR-9) ^0.26 × exp (−100 (d−
It is preferable that the relationship represented by 0.88)) + 0.1 is satisfied.

The above linear polyethylene includes ethylene and an α-olefin having 3 to 12 carbon atoms in the presence of an olefin polymerization catalyst containing a metallocene catalyst component (A) represented by the following general formula [I]. A linear polyethylene obtained by copolymerizing and is preferable.

ML ¹ _x ... [I] [wherein, M is a transition metal atom selected from Group IVB of the periodic table, and L ¹ is a ligand coordinated to the transition metal atom M] And at least one of these ligands L ¹ is
A ligand having a cyclopentadienyl skeleton, and a ligand other than a ligand having a cyclopentadienyl skeleton L ¹
Is a hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group,
An aryloxy group, a trialkylsilyl group, SO ₃ R (wherein R is a hydrocarbon group having 1 to 8 carbon atoms which may have a substituent such as halogen), a halogen atom or a hydrogen atom, and x is It is the valence of the transition metal atom M. ] Of the transition metal compounds represented by the above general formula [I],
A transition metal compound represented by the following general formula [II] is particularly preferably used.

ML ² _x ... [II] [In the formula, M is a transition metal atom selected from Group IVB of the periodic table, and L ² is a ligand coordinated to the transition metal atom M. And at least two of these ligands L ² are
Cyclopentadienyl group, methylcyclopentadienyl group, ethylcyclopentadienyl group or 3 carbon atoms
A substituted cyclopentadienyl group having at least one kind of substituent selected from hydrocarbon groups of 10 to 10, and the ligand L ² other than the (substituted) cyclopentadienyl group has 1 to 12 carbon atoms. It is a hydrocarbon group, an alkoxy group, an aryloxy group, a trialkylsilyl group, a halogen atom or a hydrogen atom, and x is the valence of the transition metal atom M. In the present specification, the term “metallocene” is used to mean a cyclopentadienyl complex salt having at least one cyclopentadiene ring.

In the present invention, a retort container made of a linear polyethylene composition in which 5 to 30 parts by weight of high-density polyethylene is added to the above-mentioned linear polyethylene based on 100 parts by weight of the total amount of both components is preferable. .

The retort container is suitable as a medical container and a food container.

[0018]

DETAILED DESCRIPTION OF THE INVENTION The retort container according to the present invention will be specifically described below. The retort container according to the present invention is a bag made of a multi-layer or a single-layer film, or a single-layer or a multi-layer bottle, etc., at least one layer of the multi-layer film, a single-layer film, at least one layer of the multi-layer bottle,
A single layer bottle is made of a particular linear polyethylene. The linear polyethylene may include high density polyethylene.

Linear Polyethylene The linear polyethylene used in the present invention is an ethylene / α-olefin copolymer obtained by copolymerizing ethylene and an α-olefin having 3 to 12 carbon atoms.

Specific examples of such α-olefins include propylene, butene-1, hexene-1,4-methyl.
-1-Pentene, octene-1 and the like. Above all,
Hexene-1,4-methyl-1-pentene and octene-1 are preferred.

In the linear polyethylene used in the present invention, the structural unit derived from ethylene is usually present in a proportion of 95 to 99 mol%, preferably 96 to 98 mol%, and α-containing 3 to 12 carbon atoms. The structural unit derived from the olefin is usually present in a proportion of 1 to 5 mol%, preferably 2 to 4 mol%.

The composition of linear polyethylene is usually 10 m.
Approximately 200 mg of linear polyethylene in a mφ sample tube
A test sample that was uniformly dissolved in 1 ml of hexachlorobutadiene.
Fee ¹³The C-NMR spectrum was measured at a measurement temperature of 120 ° C.
Constant frequency 25.05MHz, spectrum width 1500H
z, pulse repetition time 4.2 sec., pulse width 6 μsec.
It is determined by measuring under the measuring conditions.

This linear polyethylene has a density of 0.9.
18 to 0.940 g / cm ³ , preferably 0.920 to
It is in the range of 0.930 g / cm ³ . When the linear polyethylene having a density within the above range is used, a retort container that is free from deformation and wrinkles when sterilized at a sterilization temperature of 115 ° C. or higher can be obtained.

The melt flow rate of this linear polyethylene (MFR; ASTM D1238, 190)
C, load 2.16 kg) is usually 0.1-20 g / 10
Min, preferably 0.2 to 10 g / 10 min, more preferably 0.5 to 5 g / 10 min.

The linear polyethylene used in the present invention has a molecular weight distribution (Mw / Mn:
Mw = weight average molecular weight, Mn = number average molecular weight) is 1.5
˜3.0, preferably 1.5 to 2.5.

The molecular weight distribution (Mw / Mn) was measured as follows using GPC-150C manufactured by Millipore. The separation column is TSK GNH HT,
The column size is 72 mm in diameter and 600 mm in length,
The column temperature was 140 ° C., O-dichlorobenzene (manufactured by Wako Pure Chemical Industries, Ltd.) as the mobile phase, and 0.025% by weight of BHT (manufactured by Takeda Pharmaceutical Co., Ltd.) as an antioxidant were used. It was moved at 0 ml / min, the sample concentration was 0.1% by weight, the sample injection amount was 500 microliters, and a differential refractometer was used as a detector. Standard polystyrene is
For the molecular weights of Mw <1000 and Mw> 4 × 10 ⁶ , those manufactured by Tosoh Corporation were used, and 1000 <Mw <4 × 10
^{As for 6} , a pressure chemical product was used.

The layer made of linear polyethylene used in the present invention has a haze (ASTM) after retort sterilization.
D-1003-61) is 30% or less, preferably 20 to
It is 0%.

The layer of linear polyethylene used in the present invention has a deformation starting temperature (Td [° C.]) higher than the sterilization temperature. The deformation start temperature (Td
[° C]) is measured as follows. That is, a bag made of a single-layer film molded from linear polyethylene or a sample of a single-layer bottle was used as a sample of RK-40 manufactured by Alp Co.
Sterilization temperature x 3 in a 16-inch small retort high-pressure steam sterilizer
Perform hot water sterilization for 0 minutes, and visually observe the sample taken out from the sterilizer to evaluate its deformation. Starting from a sterilization temperature of 110 ° C, increase the sterilization temperature setting by 1 ° C after each sterilization. When this sample is taken out of the sterilizer and deformation is observed for the first time, the sterilization temperature is defined as the deformation start temperature (Td [° C]).

In the linear polyethylene used in the present invention, the decane-soluble component amount fraction (W [wt%]) and the density (d [g / cm ³ ]) at 23 ° C. are shown below. It is preferable that the relationship is satisfied.

When MFR ≦ 10 g / 10 min, W <80 × exp (−100 (d−0.88)) + 0.1 MFR> 10 g / 10 min, W <80 × (MFR-9) ^0.26 × exp (-100 (d-
0.88)) + 0.1 The measurement of the n-decane soluble component amount of linear polyethylene (the smaller the soluble component amount, the narrower the composition distribution) is to add about 3 g of polyethylene to 450 ml of n-decane, After dissolving at 145 ° C., cooling to 23 ° C., the n-decane-insoluble portion is removed by filtration, and the n-decane-soluble portion is recovered from the filtrate.

Further, the linear polyethylene has a temperature (Tm [° C.]) and a density (d [g / cm] at the maximum peak position of the endothermic curve measured by a differential scanning calorimeter (DSC).
³ ]) satisfies the relationship represented by: Tm <400 × d-250, preferably Tm <450 × d-297, more preferably Tm <500 × d-344, particularly preferably Tm <550 × d-391. Is desirable.

The temperature (Tm) at the maximum peak position of the endothermic curve measured by a differential scanning calorimeter (DSC) was such that about 5 mg of a sample was packed in an aluminum pan and heated to 200 ° C. at 10 ° C./min. It is obtained from the endothermic curve when the temperature is lowered to room temperature at 20 ° C./min, and then the temperature is raised at 10 ° C./min. Measured by Perkin Elmer DS
Use a C-7 type device.

Thus, the relationship between the n-decane-soluble component amount fraction (W) and the density (d), and the temperature (Tm) at the maximum peak position in the endothermic curve measured by the differential scanning calorimeter (DSC). It can be said that the linear polyethylene having a relationship between the above () and the density (d) has a narrow composition distribution.

In the present invention, the above linear polyethylene may be used alone or in combination of two or more kinds. In the present invention, among the linear polyethylenes having the above characteristics, ethylene and α-olefin having 3 to 12 carbon atoms are added in the presence of an olefin polymerization catalyst containing the metallocene catalyst component (A). An ethylene / α-olefin copolymer obtained by copolymerizing the above is preferable.

Olefin polymerization catalyst [metallocene catalyst component (A)] The metallocene catalyst component (A) preferably used in the present invention has at least one ligand having a cyclopentadienyl skeleton. There are transition metal compounds of the group. Examples of such transition metal compounds include transition metal compounds represented by the following general formula [I].

ML ¹ _x ... [I] [In the formula, M is a transition metal atom selected from Group IVB of the periodic table, and L ¹ is a ligand coordinated to the transition metal atom M. And at least one of these ligands L ¹ is
A ligand having a cyclopentadienyl skeleton, and a ligand other than a ligand having a cyclopentadienyl skeleton L ¹
Is a hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group,
An aryloxy group, a trialkylsilyl group, SO ₃ R (wherein R is a hydrocarbon group having 1 to 8 carbon atoms which may have a substituent such as halogen), a halogen atom or a hydrogen atom, and x is It is the valence of the transition metal atom M. In the above general formula [I], M is a transition metal atom selected from Group IVB of the periodic table, specifically zirconium, titanium or hafnium, and preferably zirconium.

As the ligand L ¹ having a cyclopentadienyl skeleton coordinated to the transition metal atom M as described above,
For example, cyclopentadienyl group, methylcyclopentadienyl group, dimethylcyclopentadienyl group, trimethylcyclopentadienyl group, tetramethylcyclopentadienyl group, pentamethylcyclopentadienyl group,
Ethylcyclopentadienyl group, methylethylcyclopentadienyl group, propylcyclopentadienyl group, methylpropylcyclopentadienyl group, butylcyclopentadienyl group, methylbutylcyclopentadienyl group, hexylcyclopentadienyl group Groups such as alkyl-substituted cyclopentadienyl groups, or indenyl groups, 4,5,
Examples thereof include a 6,7-tetrahydroindenyl group and a fluorenyl group.

These groups may be substituted with a halogen atom, a trialkylsilyl group or the like. Among these ligands, the alkyl-substituted cyclopentadienyl group is particularly preferable.

When the compound represented by the general formula [I] contains two or more groups having a cyclopentadienyl skeleton, the groups having two cyclopentadienyl skeletons among them are ethylene, propylene and the like. Of the above, a substituted alkylene group such as isopropylidenediphenylmethylene, a silylene group or a dimethylsilylene group, a diphenylsilylene group, a substituted silylene group such as a methylphenylsilylene group, and the like.

Specific examples of the ligand L ¹ other than the ligand having a cyclopentadienyl skeleton include ¹ carbon atom.
~ 12 hydrocarbon groups, alkoxy groups, aryloxy groups,
A trialkylsilyl group, a halogen atom or a hydrogen atom is mentioned.

Examples of the hydrocarbon group having 1 to 12 carbon atoms include an alkyl group, a cycloalkyl group, an aryl group and an aralkyl group. More specifically, the alkyl group includes a methyl group, an ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group,
t-butyl group, pentyl group, hexyl group, octyl group, 2-
Examples include ethylhexyl group, decyl group, etc., examples of cycloalkyl group include cyclopentyl group, cyclohexyl group, etc., examples of aryl group include phenyl group,
Examples thereof include a tolyl group, and examples of the aralkyl group include a benzyl group and a neophyll group.

As the alkoxy group, methoxy group, ethoxy group, n-propoxy group, isopropoxy group,
Examples of n-butoxy group, isobutoxy group, sec-butoxy group, t-butoxy group, pentoxy group, hexoxy group, octoxy group and the like, aryloxy group, phenoxy group and the like, trialkylsilyl group, A trimethylsilyl group, a triethylsilyl group, a triphenylsilyl group and the like are exemplified, and halogen is fluorine,
Examples include chlorine, bromine, iodine and the like.

The ligand represented by SO ₃ R is P-
Examples thereof include a toluene sulfonate group, a methane sulfonate group, and a trifluoro methane sulfonate group. Among the transition metal compounds represented by the above general formula [I], preferable transition metal compounds include, for example, compounds represented by the following general formula [II].

ML ² _x ... [II] [In the formula, M is a transition metal atom selected from Group IVB of the periodic table, and L ² is a ligand coordinated to the transition metal atom M. And at least two of these ligands L ² are
Cyclopentadienyl group, methylcyclopentadienyl group, ethylcyclopentadienyl group or 3 carbon atoms
A substituted cyclopentadienyl group having at least one kind of substituent selected from hydrocarbon groups of 10 to 10, and the ligand L ² other than the (substituted) cyclopentadienyl group has 1 to 12 carbon atoms. It is a hydrocarbon group, an alkoxy group, an aryloxy group, a trialkylsilyl group, a halogen atom or a hydrogen atom, and x is the valence of the transition metal atom M. ] M in the above formula [II] is the same as M in the above general formula [I].

L ² is a ligand coordinated to the transition metal atom M, and at least two of these ligands L ² are cyclopentadienyl group, methylcyclopentadienyl group, ethylcyclopentadiene group. Dienyl group or 3 carbon atoms
It is a substituted cyclopentadienyl group having at least one kind of substituent selected from hydrocarbon groups of 10 to 10.

The substituted cyclopentadienyl group may have two or more substituents, and the two or more substituents may be the same or different. When the substituted cyclopentadienyl group has two or more substituents, at least one substituent may be a hydrocarbon group having 3 to 10 carbon atoms, and the other substituents are a methyl group and an ethyl group. Alternatively, it is a hydrocarbon group having 3 to 10 carbon atoms. The substituted cyclopentadienyl groups coordinated to the transition metal atom M may be the same or different.

Examples of the hydrocarbon group having 3 to 10 carbon atoms include alkyl group, cycloalkyl group, aryl group and aralkyl group. As the alkyl group, specifically, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, t-butyl group, pentyl group, hexyl group, octyl group, 2-ethylhexyl group, Examples include decyl group.

As the cycloalkyl group, specifically,
Examples thereof include a cyclopentyl group and a cyclohexyl group. Specific examples of the aryl group include a phenyl group and a tolyl group.

Specific examples of the aralkyl group include a benzyl group and a neophyll group. Of these, an alkyl group is preferable, and an n-propyl group and an n-butyl group are particularly preferable.

In the present invention, the (substituted) cyclopentadienyl group coordinated to the transition metal atom M is preferably a substituted cyclopentadienyl group, and cyclopentadienyl substituted with an alkyl group having 3 or more carbon atoms. A group is more preferable, a disubstituted cyclopentadienyl group is further preferable,
A 1,3-substituted cyclopentadienyl group is particularly preferred.

In the above formula [II], the ligand L ² other than the (substituted) cyclopentadienyl group coordinated to the transition metal atom M is a hydrocarbon group having 1 to 12 carbon atoms or an alkoxy group. , An aryloxy group, a trialkylsilyl group, a halogen atom or a hydrogen atom.

Specific examples thereof include the hydrocarbon group having 1 to 12 carbon atoms, the alkoxy group, the aryloxy group, the trialkylsilyl group and the halogen atom described above in the transition metal compound represented by the general formula [I]. The same groups and atoms as the examples can be mentioned.

Specific examples of the transition metal compound represented by the general formula [II] include bis (cyclopentadienyl) zirconium dichloride, bis (methylcyclopentadienyl) zirconium dichloride and bis (ethylcyclo). Pentadienyl) zirconium dichloride,
Bis (n-propylcyclopentadienyl) zirconium dichloride, bis (n-butylcyclopentadienyl) zirconium dichloride, bis (n-hexylcyclopentadienyl) zirconium dichloride, bis (methyl-n-
Propylcyclopentadienyl) zirconium dichloride, bis (methyl-n-butylcyclopentadienyl) zirconium dichloride, bis (dimethyl-n-butylcyclopentadienyl) zirconium dichloride, bis (n-
Butylcyclopentadienyl) zirconium dibromide, bis (n-butylcyclopentadienyl) zirconium methoxy chloride, bis (n-butylcyclopentadienyl) zirconium ethoxy chloride, bis (n-butylcyclopentadienyl) zirconium butoxy Chloride, bis (n-butylcyclopentadienyl) zirconium diethoxide, bis (n-butylcyclopentadienyl) zirconium methyl chloride, bis (n-butylcyclopentadienyl) zirconium dimethyl, bis (n-butylcyclo) Pentadienyl) zirconium benzyl chloride, bis (n-butylcyclopentadienyl) zirconium dibenzyl, bis (n-butylcyclopentadienyl) zirconium phenyl chloride, bis (n-butylcyclopentadienyl) zirconium Such as hydride chloride and the like.

In the above example, the di-substituted cyclopentadienyl ring includes 1,2- and 1,3-substituted compounds,
Tri-substitutions include 1,2,3- and 1,2,4-substitutions. Further, in the zirconium compound as described above, a transition metal compound in which zirconium metal is replaced with titanium metal or hafnium metal can be used.

Among these transition metal compounds, bis (n-propylcyclopentadienyl) zirconium dichloride, bis (n-butylcyclopentadienyl) zirconium dichloride, bis (1-methyl-3-n-propylcyclo) Pentadienyl) zirconium dichloride, bis (1-
Methyl-3-n-butylcyclopentadienyl) zirconium dichloride is particularly preferred.

[0056] In addition, the transition metal compound represented by the formula [II], of the ligand L ² with a cyclopentadienyl skeleton, two ligands L ² is a hydrocarbon group, silylene group or It may be bonded via a substituted silylene group.

Examples of the hydrocarbon group include alkylene groups such as ethylene and propylene, and substituted alkylene groups such as isopropylidene and diphenylmethylene. Examples of the substituted silylene groups include dimethylsilylene group, diphenylsilylene group and methylphenylsilylene group. Is mentioned.

Specific examples of such a transition metal compound include ethylenebis (indenyl) dimethylzirconium, ethylenebis (indenyl) diethylzirconium, ethylenebis (indenyl) diphenylzirconium, ethylenebis (indenyl) methylzirconium monochloride. , Ethylenebis (indenyl) ethylzirconium monochloride, ethylenebis (indenyl) methylzirconium monobromide, ethylenebis (indenyl) zirconium dichloride, ethylenebis (indenyl) zirconium dibromide, ethylenebis {1- (4,5,
6,7-Tetrahydroindenyl)} dimethyl zirconium, ethylenebis {1- (4,5,6,7-tetrahydroindenyl)} methylzirconium monochloride, ethylenebis {1- (4,5,6,7- Tetrahydroindenyl)} zirconium dichloride, ethylene bis {1- (4,5,6,7-tetrahydroindenyl)} zirconium dibromide, ethylene bis {1- (4-methylindenyl)} zirconium dichloride, ethylene bis { 1- (5-methylindenyl)} zirconium dichloride, ethylenebis {1- (6-methylindenyl)} zirconium dichloride, ethylenebis {1-
(7-Methylindenyl)} zirconium dichloride, ethylenebis {1- (5-methoxyindenyl)} zirconium dichloride, ethylenebis {1- (2,3-dimethylindenyl)} zirconium dichloride, ethylenebis {1-
(4,7-Dimethylindenyl)} zirconium dichloride, ethylene bis {1- (4,7-dimethoxyindenyl)}
Zirconium dichloride, isopropylidene (cyclopentadienyl-fluorenyl) Zirconium dichloride, isopropylidene (cyclopentadienyl-2,7-di
-t-Butylfluorenyl) zirconium dichloride, isopropylidene (cyclopentadienyl-methylcyclopentadienyl) zirconium dichloride, dimethylsilylenebis (cyclopentadienyl) zirconium dichloride, dimethylsilylenebis (methylcyclopentadienyl) Zirconium dichloride, dimethylsilylenebis (dimethylcyclopentadienyl) zirconium dichloride, dimethylsilylenebis (trimethylcyclopentadienyl) zirconium dichloride, dimethylsilylenebis (indenyl) zirconium dichloride, diphenylsilylenebis (indenyl) zirconium dichloride and the like. .

In the above example, the di-substituted cyclopentadienyl ring includes 1,2- and 1,3-substituted compounds,
Tri-substitutions include 1,2,3- and 1,2,4-substitutions. In the present invention, a transition metal compound in which zirconium metal is replaced with titanium metal or hafnium metal in the above zirconium compound can be used.

Among these transition metal compounds, ethylenebis (indenyl) zirconium dichloride, dimethylsilylenebis (indenyl) zirconium dichloride and diphenylsilylenebis (indenyl) zirconium dichloride are particularly preferable.

In the present invention, at least one compound selected from the above-mentioned transition metal compounds is used as the metallocene catalyst component (A). [Organoaluminum Oxy Compound Catalyst Component (B)] A typical example of the organoaluminum oxy compound catalyst component (B) used for preparing the olefin polymerization catalyst is aluminoxane. Specifically, the repeating unit represented by the formula -Al (R) O- [wherein R is an alkyl group] is usually about 3 to 50 methylaluminoxane, ethylaluminoxane, methylethylaluminoxane. Etc. are used.

Such an aluminoxane can be prepared by a conventionally known production method, and can be obtained by reacting at least one or more organoaluminum compound such as trialkylaluminum with water. Specifically, the following method for producing aluminoxane can be mentioned. (1) Compounds containing adsorbed water or salts containing water of crystallization, such as magnesium chloride hydrate, copper sulfate hydrate, aluminum sulfate hydrate, nickel sulfate hydrate, ceric chloride hydrate, etc. A method of adding an organoaluminum compound such as trialkylaluminum to the hydrocarbon medium suspension of, and reacting the organoaluminum compound with adsorption water or crystallization water. (2) A method in which water, ice, or steam is directly applied to an organoaluminum compound such as trialkylaluminum in a medium such as benzene, toluene, ethyl ether, or tetrahydrofuran.

Among these methods, the method (1) is preferably adopted. The aluminoxane may contain a small amount of an organometallic component other than aluminum. Alternatively, the solvent or unreacted organoaluminum compound may be removed by distillation from the recovered solution of the aluminoxane, and then redissolved in the solvent.

Specific examples of the organoaluminum compound used when preparing the aluminoxane include trimethylaluminum, triethylaluminum, tripropylaluminum, triisopropylaluminum, and triisopropylaluminum.
n-butyl aluminum, triisobutyl aluminum,
Trisec-butylaluminum, tritert-butylaluminum, tripentylaluminum, trihexylaluminum, trioctylaluminum, tridecylaluminum and other trialkylaluminums; tricyclohexylaluminum, tricyclooctylaluminum and other tricycloalkylaluminums; dimethylaluminum Dialkyl aluminum halides such as chloride, diethyl aluminum chloride, diethyl aluminum bromide and diisobutyl aluminum chloride; Dialkyl aluminum hydrides such as diethyl aluminum hydride and diisobutyl aluminum hydride; Dialkyl aluminum alkoxides such as dimethyl aluminum methoxide and diethyl aluminum ethoxide; diethyl aluminum Examples thereof include dialkylaluminum aryloxides such as aluminum phenoxide. Of these organoaluminum compounds, trialkylaluminums and tricycloalkylaluminums are particularly preferred.

[Fine Particulate Carrier] The fine particle carrier used in the preparation of the olefin polymerization catalyst is an inorganic or organic compound having a particle size of usually about 10 to 300 μm, preferably 20 to 200 μm. To a solid in the form of fine particles.

Of these, porous oxides are preferable as the inorganic carrier, and specifically, SiO ₂ , Al ₂ O ₃ and Mg are used.
O, ZrO ₂ , TiO ₂ , B ₂ O ₃ , CaO, ZnO, B
aO, ZnO ₂ , SnO ₂ , ThO _2, etc. or mixtures thereof such as SiO ₂ —MgO, SiO ₂ —Al ₂ O ₃ ,
SiO ₂ -TiO ₂ , SiO ₂ -V ₂ O ₅ , SiO ₂ -Cr
₂ O ₃ , SiO ₂ —TiO ₂ —MgO and the like can be exemplified. Among these, oxides containing as a main component at least one component selected from the group consisting of SiO ₂ and Al ₂ O ₃ are preferable.

The above inorganic oxide contains a small amount of Na ₂
CO ₃ , K ₂ CO ₃ , CaCO ₃ , MgCO ₃ , Na ₂ SO
₄ , Al ₂ (SO ₄ ) ₃ , BaSO ₄ , KNO ₃ , Mg
(NO ₃ ) ₂ , Al (NO ₃ ) ₃ , Na ₂ O, K ₂ O, L
It may contain a carbonate, a sulfate, a nitrate or an oxide component such as i ₂ O.

The properties of such a carrier differ depending on the type and production method, but the carrier preferably used in the present invention has a specific surface area of 50 to 1000 m ² / g, preferably 1
0 to 700 m ² / g and a pore volume of 0.3 to 2.
It is preferably 5 cm ³ / g.

This carrier may contain 100 to 100, if necessary.
It is used by firing at 0 ° C, preferably 150 to 700 ° C. Further, as the organic compound used as the particulate carrier, ethylene, propylene, 1-butene, 4-methyl-1
Examples include (co) polymers containing α-olefins having 2 to 14 carbon atoms such as pentene as a main component, or polymers or copolymers containing vinylcyclohexane or styrene as a main component. it can.

[Organoaluminum compound catalyst component (C)] An organoaluminum compound catalyst component (C) used as necessary in the preparation of the olefin polymerization catalyst.
Specifically, trimethylaluminum, triethylaluminum, triisopropylaluminum,
Trialkylaluminums such as triisobutylaluminum, trioctylaluminum and tri-2-ethylhexylaluminum; alkenylaluminums such as isoprenylaluminum; dimethylaluminum chloride, diethylaluminium chloride, diisopropylaluminum chloride, diisobutylaluminum chloride, dimethylaluminum bromide and other dialkylaluminums. Alkyl aluminum sesquihalides such as methyl aluminum sesquichloride, ethyl aluminum sesquichloride, isopropyl aluminum sesquichloride, butyl aluminum sesquichloride, ethyl aluminum sesquibromide; methyl aluminum dichloride, ethyl aluminum dichloride, isopropyl aluminum dichloride De, alkylaluminum dihalides such as ethylaluminum dibromide; diethylaluminum hydride, and alkyl aluminum hydride such as diisobutyl aluminum hydride can be exemplified.

[Other catalyst components] As other catalyst components that can be used in combination with the metallocene catalyst component (A),
Further ionized ionic compounds such as USP-54.
The Lewis acid, the ionic compound, and the carborane compound described in 7718 are mentioned.

As the Lewis acid, triphenylboron,
Tris (4-fluorophenyl) boron, Tris (p-tolyl) boron, Tris (o-tolyl) boron, Tris (3,5-
Dimethylphenyl) boron, tris (pentafluorophenyl) boron, MgCl ₂ , Al ₂ O ₃ , SiO ₂ -Al
₂ O ₃ can be exemplified.

As the ionic compound, triphenylcarbenium tetrakis (pentafluorophenyl) borate, tri-n-butylammonium tetrakis (pentafluorophenyl) borate, N, N-dimethylanilinium tetrakis (pentafluorophenyl) borate, ferroferrite Examples include cerium tetra (pentafluorophenyl) borate.

Examples of the carborane compound include dodecaborane, 1-carbaundecaborane, bis-n-butylammonium (1-carbedodeca) borate, tri-n-butylammonium (7,8-dicarbaundeca) borate and tri-n-butylammonium. (Trideca hydride-7-carbaundeca) borate can be exemplified.

The ionizable ionic compound catalyst component (D) can be used alone or in combination of two or more kinds. [Preparation of Olefin Polymerization Catalyst] The olefin polymerization catalyst used in the preparation of the linear polyethylene of the present invention includes the above-mentioned particulate carrier, the metallocene catalyst component (A), and the organoaluminum oxy compound catalyst component ( B), but a catalyst component that can be used in combination with the metallocene catalyst component (A) described above, that is, a catalyst component such as an organoaluminum compound catalyst component (C) and an ionized ionic compound catalyst component (D). You may use a part or all.

Particulate carrier and metallocene catalyst component (A)
And / or the catalyst component such as the organoaluminum oxy compound catalyst component (B) is brought into contact with, for example, the particulate support and the metallocene catalyst component (A) and / or the organoaluminum oxy compound catalyst component in an inert hydrocarbon solvent. The catalyst component such as (B) is mixed.

Specific examples of the inert hydrocarbon solvent include aliphatic hydrocarbons such as propane, butane, pentane, hexane, heptane, octane, decane, dodecane, and kerosene; cyclopentane, cyclohexane, methylcyclopentane, etc. Examples thereof include alicyclic hydrocarbons; aromatic hydrocarbons such as benzene, toluene and xylene; halogenated hydrocarbons such as ethylene chloride, chlorobenzene and dichloromethane; and mixtures thereof.

A fine particle carrier, a metallocene catalyst component (A), an organoaluminum oxy compound catalyst component (B), an organoaluminum compound catalyst component (C) and an ionized ionic compound catalyst for preparing the above olefin polymerization catalyst. The order of contacting the catalyst components such as the component (D) is arbitrarily selected, but preferably the fine particle carrier and the catalyst component such as the organoaluminum oxy compound catalyst component (B) and / or the ionized ionic compound catalyst component (D). And are brought into mixed contact, and then the metallocene catalyst component (A) is brought into mixed contact.

When the organoaluminum compound catalyst component (C) is used, the particulate carrier and the organoaluminum oxy compound catalyst component (B) are mixed and contacted, and then the metallocene catalyst component (A) is mixed and contacted, and the organoaluminum is further added. The compound catalyst component (C) is mixed and brought into contact.

The catalyst components used when the catalyst components are mixed and brought into contact with the particulate carrier are used in the following ratios, for example. Particulate carrier, metallocene catalyst component (A)
When the mixed component and the organoaluminum oxy compound catalyst component (B) are brought into contact with each other, the component (A) is usually converted to a transition metal atom of 5 × 10 ⁻⁶ to 1 g of the particulate support.
It is used in an amount of 5 × 10 ⁻⁴ mol, preferably 10 ⁻⁵ to 2 × 10 ⁻⁴ mol, and the concentration of the component (A) is about 10 ⁻⁴ to 2 × 1.
0 ^-2 mol / liter (solvent), preferably 2 x 10 ^-4 ~
It is in the range of 10 ^-2 mol / liter (solvent).

The organoaluminum oxy compound catalyst component (B) has an atomic ratio [Al / transition metal] of aluminum atoms in the component (B) and transition metal atoms in the component (A).
Is usually 10 to 500, preferably 20 to 200.

When the organoaluminum compound catalyst component (C) is used, the component (B) is used in the same amount as described above, and the component (C) contains the aluminum atom in the component (C) and the component (B). The atomic ratio [Al of the component (C) / Al of the component (B)] with the aluminum atom therein is usually 0.02 to
It is used in an amount of 3, preferably 0.05 to 1.5.

When the ionizable ionic compound catalyst component (D) is used, the component (D) usually has a molar ratio [component (A) / component (D)] of 0. 01-
It is used in an amount of 10, preferably 0.1 to 5.

Particulate carrier, metallocene catalyst component (A)
And an organoaluminum oxy compound catalyst component (B),
Further, the mixing temperature for mixing and contacting the catalyst components such as the organoaluminum compound (C) and the ionized ionic compound catalyst component (D), which are used as necessary, is usually -50 ° C.
To 150 ° C, preferably -20 ° C to 120 ° C, and the contact time is 1 minute to 50 hours, preferably 10 minutes to 25 hours.

The solid catalyst thus obtained was
For example, metallocene catalyst component (A) and organoaluminum
In addition to the oxy compound catalyst component (B), organic aluminum
When the solid compound catalyst component (C) is included, the solid catalyst
The medium is derived from the component (A) per 1 g of the particulate carrier.
5 × 10 transfer metal atoms^-6~ 5 × 10^-FourGram atom, preferred
It is 10^-Five~ 2 x 10^-FourSupported in the amount of gram atoms,
Ingredient (B) and ingredient (C) per gram of particulate carrier
10 aluminum atoms derived from^-3~ 5 × 10 ^-2G
Atoms, preferably 2 × 10^-3~ 2 x 10^-2Gram atom
It is desirable that the carrier be supported in an amount.

[Preparation of Linear Polyethylene] The linear polyethylene (ethylene / α-olefin copolymer) used in the present invention is a olefin polymerization catalyst containing the metallocene catalyst component (A) as described above. It can be obtained by copolymerizing ethylene and an α-olefin having 3 to 12 carbon atoms in the presence of gas phase or liquid phase of slurry or solution under various conditions.

In the slurry polymerization method or the solution polymerization method, an inert hydrocarbon may be used as the solvent, or the olefin itself may be used as the solvent. As the inert hydrocarbon solvent used in the slurry polymerization method and the solution polymerization method,
Specifically, propane, butane, isobutane, pentane, hexane, octane, decane, dodecane, hexadecane, octadecane, and other aliphatic hydrocarbons; cyclopentane, methylcyclopentane, cyclohexane, cyclooctane, and other alicyclic hydrocarbons; Aromatic hydrocarbons such as benzene, toluene and xylene; petroleum fractions such as gasoline, kerosene, and light oil. Of these inert hydrocarbon solvents, aliphatic hydrocarbons, alicyclic hydrocarbons and petroleum fractions are preferred.

When carrying out the polymerization, the olefin polymerization catalyst as described above is usually at a concentration of transition metal atoms in the polymerization reaction system of usually 10 ⁻⁸ to 10 ⁻³ g atom / liter, preferably 10 It is preferably used in an amount of ^-7 to 10 ^-4 g atom / liter.

Further, in the polymerization, in addition to the organoaluminum oxy compound catalyst component (B) and the organoaluminum compound catalyst component (C) which are supported on the carrier, the organoaluminum oxy compound catalyst component (B) which is not supported on the carrier is further added. And / or the organoaluminum compound catalyst component (C) may be used. In this case, the aluminum atom (Al) derived from the unsupported organoaluminum oxy compound catalyst component (B) and / or the organoaluminum compound catalyst component (C) and the transition metal atom (A) derived from the metallocene catalyst component (A) ( M) atomic ratio [Al
/ M] is in the range of 5 to 300, preferably 10 to 200, and more preferably 15 to 150.

The polymerization temperature in the slurry polymerization method is usually -50 to 100 ° C, preferably 0 to 90 ° C, and the polymerization temperature in the solution polymerization method is usually -50 to 50 ° C.
It is in the range of 0 ° C, preferably 0 to 400 ° C. The polymerization temperature in the gas phase polymerization method is usually 0 to 120 ° C, preferably 20 to 100 ° C.

The polymerization pressure is usually atmospheric pressure to 100 kg /
It is under a pressure condition of cm ² , preferably ² to 50 kg / cm ² , and the polymerization can be carried out by any of batch system, semi-continuous system and continuous system.

In the present invention, (1) multi-stage polymerization, (2) liquid-phase and gas-phase multi-stage polymerization, or (3) pre-polymerization in liquid phase may be carried out in the preparation of the above linear polyethylene, if necessary. Means such as carrying out the polymerization in the gas phase after the reaction can be adopted.

It was obtained that the retort container made of linear polyethylene prepared by using the olefin polymerization catalyst containing the metallocene catalyst component (A) as described above can withstand the sterilization treatment at 115 ° C. or higher. This is due to the physical properties of the polymer. That is, due to the effect of the metallocene catalyst component (A) constituting the olefin polymerization catalyst, linear polyethylene having a narrow molecular weight distribution and composition distribution and a small amount of low polymer is produced. This is also confirmed from the endothermic curve measured by a differential scanning calorimeter (DSC).

The retort container made of the linear polyethylene of the present invention is not deformed or its transparency is deteriorated during the sterilization treatment at 115 ° C. or higher. In contrast,
The conventional container made of linear polyethylene has been insufficient as a retort container because of deformation or deterioration of transparency during sterilization at 115 ° C or higher. .

In the linear polyethylene of the present invention, for example, Example 2 described later, a sharp peak is seen as shown in FIG. On the other hand, the endothermic curves measured by a differential scanning calorimeter of conventional linear polyethylene, for example, linear polyethylene prepared using the titanium-based supported catalyst of Comparative Example 1 described later, are compared as shown in FIG. Shows a broad peak.

Therefore, it is considered that whether or not the linear polyethylene has a sharp peak is involved in maintaining the shape and transparency of the container during the sterilization treatment at 115 ° C. or higher.

High Density Polyethylene The high density polyethylene optionally used in the present invention is an ethylene / α-olefin copolymer obtained by copolymerizing ethylene and an α-olefin having 3 to 12 carbon atoms. is there.

Specific examples of such α-olefins include propylene, butene-1, hexene-1,4-methyl.
-1-Pentene, octene-1 and the like. Above all,
Hexene-1,4-methyl-1-pentene and octene-1 are preferred.

The high-density polyethylene used in the present invention has a constitutional unit derived from ethylene in an amount of usually 95 to 99 mol%, preferably 96 to 98 mol%, and an α-olefin having 3 to 12 carbon atoms. The structural unit derived from is usually present in a proportion of 1 to 5 mol%, preferably 2 to 4 mol%.

The composition of high-density polyethylene is usually 10 m.
Approximately 200 mg of high-density polyethylene in a mφ sample tube
A test sample that was uniformly dissolved in 1 ml of hexachlorobutadiene.
Fee ¹³The C-NMR spectrum was measured at a measurement temperature of 120 ° C.
Constant frequency 25.05MHz, spectrum width 1500H
z, pulse repetition time 4.2 sec., pulse width 6 μsec.
It is determined by measuring under the measuring conditions.

This high-density polyethylene has a density of 0.9.
70 g / cm ³ range above 0.940 g / cm ³ or less, preferably in the range of 0.945~0.965g / cm ^3. When the high-density polyethylene having a density within the above range is used, a linear polyethylene composition having a high deformation initiation temperature (Td) and capable of forming a film or a bottle with almost no loss in transparency can be obtained. When such a composition is used, the sterilization temperature (retort temperature) can be increased and the sterilization time (retort time) can be shortened.

The melt flow rate (MFR; ASTM D 1238, 190 ° C., load 2.16 kg) of this high density polyethylene is usually 0.1 to 20 g / 10 min, preferably 1.0 to 15 g / 10 min, and further Preferably 2.
It is in the range of 0 to 15 g / 10 minutes.

The high-density polyethylene as described above can be prepared by a conventionally known method such as the so-called Ziegler method or Phillips method. In the present invention, the high-density polyethylene is 5 to 30 parts by weight, preferably 5 to 20 parts by weight, and more preferably 5 to 10 parts by weight, based on 100 parts by weight of the total amount of the linear polyethylene and the high-density polyethylene. Used in proportions by weight.

[Manufacture of Retort Container] The retort container according to the present invention is, as already described above, a bag made of a multilayer film, a bag made of a single layer film or a bottle made of a single layer and a multilayer. At least 1
Layer, single layer film, at least one layer of multilayer bottle, single layer bottle is formed of linear polyethylene having a density of 0.918 to 0.940 g / cm ³ prepared using the above-mentioned olefin polymerization catalyst. ing.

The retort container according to the present invention can be manufactured by a water-cooled or air-cooled inflation method, a T-die method, a dry lamination method, an extrusion lamination method, a hollow molding method and the like.

As a method of forming the retort bag, hygiene,
Inflation method and co-extrusion T
A die method is preferred, and a hollow molding method is preferred for molding the retort bottle.

The retort container of the present invention has a thickness of 0.05.
˜1.00 mm, preferably 0.1 to 0.7 mm, more preferably 0.15 to 0.3 mm. When the thickness of the container is 0.05 mm or more, the impact resistance is good and there is no practical problem.

[0108]

INDUSTRIAL APPLICABILITY The retort container according to the present invention has good hygiene and flexibility, does not lose transparency even when sterilized at 115 ° C. or higher, and has excellent heat resistance, and wrinkles and deformation occur. There is nothing to do. In particular, since the retort container formed of the above-described composition composed of linear polyethylene and high-density polyethylene has excellent heat resistance, it is possible to increase the sterilization temperature and shorten the sterilization time. it can.

The retort container according to the present invention exhibits excellent performance as a medical container and a food container. Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to these examples.

The physical properties of hollow molded articles (bottles) and films in Examples and Comparative Examples were evaluated as follows. (1) Density The density of polyethylene was measured at a temperature of 23 ± 0.1 ° C. according to the method D of JIS K7112. (2) Melt Flow Rate (MFR) The melt flow rate of polyethylene is ASTM D 1
It measured according to 238 (190 degreeC, load 2.16 kg). (3) Haze (Transparency) The haze which is an index of the transparency of the hollow molded article and the film which has been subjected to the retort treatment at 115 ° C. for 30 minutes is ASTM D-1.
It was measured according to 003-61. (4) Appearance The appearance of the hollow molded product and the film that have been retort treated at 115 ° C for 30 minutes is visually observed, and the appearance evaluation when deformation is observed is indicated by x, and the appearance evaluation when no deformation is observed. Is indicated by ◯, and the appearance evaluation in the case where the patchy haze is generated although the deformation is recognized is indicated by Δ. (5) Young's modulus (flexibility) Young's modulus was measured according to JIS K 6781.

[0111]

Example 1 [Preparation of Catalyst for Olefin Polymerization] 6.3 kg of silica dried at 250 ° C. for 10 hours was suspended in 100 liter of toluene and then cooled to 0 ° C. Then, a toluene solution of methylaluminoxane (Al; 0.96 mol /
41 liters) was added dropwise in 1 hour. On this occasion,
The temperature in the system was kept at 0 ° C. Subsequently, the mixture was reacted at 0 ° C for 60 minutes, then heated to 95 ° C over 1.5 hours, and reacted at that temperature for 4 hours. Then, the temperature was lowered to 60 ° C., and the supernatant was removed by the decantation method.

The solid component thus obtained was washed twice with toluene and then resuspended in 125 liters of toluene. To this system, a solution of bis (n-butylcyclopentadienyl) zirconium dichloride in toluene (Zr; 4
2.7 mmol / liter) 15 liters at 30 ° C.
The mixture was added dropwise over 0 minutes, and further reacted at 30 ° C. for 2 hours.
Then, the supernatant was removed, and the solid catalyst was washed twice with hexane to obtain a solid catalyst containing 6.2 mg of zirconium per 1 g.

[Preparation of prepolymerization catalyst] To 300 liters of hexane containing 14 mol of triisobutylaluminum, 8.5 kg of the solid catalyst obtained above was added, and 3
By prepolymerizing ethylene at 5 ° C for 7 hours,
A prepolymerized catalyst was obtained in which 3 g of polyethylene was prepolymerized per 1 g of the solid catalyst.

[Preparation of linear polyethylene] Copolymerization of ethylene and 1-hexene was carried out using a continuous fluidized bed gas phase polymerization apparatus at a total pressure of 18 kg / cm ² -G and a polymerization temperature of 80 ° C. The prepolymerization catalyst prepared above was continuously supplied at a rate of 0.15 mmol / h in terms of zirconium atom and triisobutylaluminum at a rate of 10 mmol / h, and ethylene was added in order to maintain a constant gas composition during the polymerization. 1-Hexene, hydrogen, and nitrogen were continuously supplied (gas composition; 1-hexene / ethylene = 0.021, hydrogen / ethylene = 0.
0015, ethylene concentration = 16%). The yield of linear polyethylene thus obtained is 5.0 kg / h, the density is 0.920 g / cm ³ , the melt flow rate is 3.7 g / 10 min, and the decane at 23 ° C. The soluble component amount fraction was 0.8% by weight, Mw / Mn was 2.2, and Tm was 116 ° C.

[Production of Hollow Molded Product] From this linear polyethylene, a cylinder temperature of 160 to 180 ° C., a die temperature of 180 ° C., a mold temperature of 20 ° C. and a blow pressure of 3 kg / cm were used by using a blow molding machine manufactured by Placo. ^A hollow molded product (bottle) was molded under the condition of ² G. The hollow molded product thus obtained was subjected to retort treatment at 115 ° C. for 30 minutes, and then the haze, appearance and Young's modulus were measured and evaluated by the methods described above. The results are shown in Table 1.

[0116]

Example 2 A linear polyethylene having the characteristic values shown in Table 1 was prepared in the same manner as in Example 1, and a hollow molded article was obtained from this linear polyethylene in the same manner as in Example 1. .

About the obtained hollow molded article,
After 30 minutes of retort treatment, haze, appearance and Young's modulus were measured or evaluated by the methods described above. First result
Shown in the table.

The endothermic curve of the linear polyethylene used in Example 2 measured with a differential scanning calorimeter is shown in FIG.
Shown in

[0119]

Comparative Example 1 [Preparation of Olefin Polymerization Catalyst] In a nitrogen stream, 10 mol of commercially available anhydrous magnesium chloride was suspended in 50 liters of dehydrated and purified hexane, and stirred with ethanol 60.
After mol was added dropwise over 1 hour, the mixture was reacted at room temperature for 1 hour. Then, 27 mol of diethylaluminum chloride was added dropwise to this reaction solution at room temperature, and the mixture was stirred for 1 hour. Subsequently, after adding 100 mol of titanium tetrachloride, the temperature of the system was raised to 70 ° C. and the reaction was carried out while stirring for 3 hours. The produced solid part was separated by decantation, washed repeatedly with purified hexane, and made into a hexane suspension.

[Preparation of linear polyethylene] In a 200 liter continuous polymerization reactor, 80 liter / hr of dehydrated and purified solvent hexane and 1.2 mmol / hr of the carrier-supported catalyst in terms of titanium were continuously added. 13 kg / hr of ethylene and 1-butene 13.
0 kg / hr and 100 liters / hr of hydrogen were continuously supplied at a polymerization temperature of 145 ° C. and a total pressure of 30 kg / cm ² G,
The copolymer was prepared under the conditions that the residence time was 1 hour and the concentration of the copolymer in the solvent hexane was 120 g / l.

The linear polyethylene obtained as described above has a density of 0.920 g / cm ³ , a melt flow rate of 2.0 g / 10 min, and a decane-soluble component fraction at 23 ° C. Is 2.7% by weight, Mw / Mn
Was 2.8 and Tm was 116 ° C.

The endothermic curve of this linear polyethylene measured with a differential scanning calorimeter is shown in FIG.

[Production of Hollow Molded Product] The above linear polyethylene was molded under the same conditions as in Example 1 to obtain a hollow molded product. The resulting hollow molded article was subjected to retort treatment at 115 ° C. for 30 minutes, and then the haze, appearance and Young's modulus were measured or evaluated by the methods described above. The results are shown in Tables 1 and 5.

[0124]

Comparative Example 2 [Preparation of linear polyethylene] 200 liter continuous weight
100 liters of dehydrated and purified solvent hexane was added to the combined reactor.
Le / hr, 0.4 in terms of the catalyst with the carrier converted to titanium
5 mmol / hr, triethylaluminum 10 mm
Mol / hr is continuously supplied, and at the same time in the polymerization vessel,
Tilene 13 kg / hr, 4-methylpentene-1 38 liters
Tor / hr and hydrogen 35Nl / hr continuously supplied,
Polymerization temperature 165 ° C, total pressure 30 kg / cm ² G, residence time
1 hour, the concentration of the copolymer in the solvent hexane is 130
The copolymer was prepared under the condition of g / l. above
The linear polyethylene thus obtained has a density of 0.9.
20 g / cm³And the melt flow rate is 2.0 g
/ 10 minutes, the decane soluble component amount fraction at 23 ° C.
Is 3.3% by weight, Mw / Mn is 4.0, and T
m was 122 ° C.

[Production of Hollow Molded Product] The above linear polyethylene was molded under the same conditions as in Example 1 to obtain a hollow molded product. The resulting hollow molded article was subjected to retort treatment at 115 ° C. for 30 minutes, and then the haze, appearance and Young's modulus were measured or evaluated by the methods described above. The results are shown in Tables 1 and 5.

[0126]

[Table 1]

[0127]

[Example 3] [Production of film] The linear polyethylene of Example 1 was
A cast film molding machine manufactured by Modern Co., Ltd. was used to mold the film under the conditions of a cylinder temperature of 180 to 220 ° C., a die temperature of 220 ° C., and a roll temperature of 30 ° C. to obtain a film having a thickness of 200 μm.

About the obtained film, 115 ° C., 3
After the retort treatment for 0 minutes, haze, appearance and Young's modulus were measured or evaluated by the methods described above. The results are shown in Table 2.

[0129]

Example 4 A film having a thickness of 200 μm was obtained in the same manner as in Example 3 except that the linear polyethylene of Example 2 was used instead of the linear polyethylene of Example 1. It was About the obtained film, 115
After retort treatment at 30 ° C. for 30 minutes, haze, appearance and Young's modulus were measured or evaluated by the methods described above. The results are shown in Table 2.

[0130]

Comparative Example 3 A film having a thickness of 200 μm was obtained in the same manner as in Example 3 except that the linear polyethylene of Comparative Example 1 was used instead of the linear polyethylene of Example 1. It was About the obtained film, 115
After retort treatment at 30 ° C. for 30 minutes, haze, appearance and Young's modulus were measured or evaluated by the methods described above. The results are shown in Table 2.

[0131]

Comparative Example 4 A film having a thickness of 200 μm was obtained in the same manner as in Example 3 except that the linear polyethylene of Comparative Example 2 was used instead of the linear polyethylene of Example 1. It was About the obtained film, 115
After retort treatment at 30 ° C. for 30 minutes, haze, appearance and Young's modulus were measured or evaluated by the methods described above. The results are shown in Table 2.

[0132]

[Table 2]

[0133]

Example 5 [Production of film] The linear polyethylene of Example 1 was
A cast film molding machine manufactured by Modern Co., Ltd. was used to mold the film under the conditions of a cylinder temperature of 180 to 220 ° C., a die temperature of 220 ° C., and a roll temperature of 30 ° C. to obtain a film having a thickness of 100 μm. About the obtained film, 115
After retort treatment at 30 ° C. for 30 minutes, haze, appearance and Young's modulus were measured or evaluated by the methods described above. The results are shown in Table 3.

[0134]

Example 6 A film having a thickness of 100 μm was obtained in the same manner as in Example 5, except that the linear polyethylene of Example 2 was used instead of the linear polyethylene of Example 1. It was About the obtained film, 115
After retort treatment at 30 ° C. for 30 minutes, haze, appearance and Young's modulus were measured or evaluated by the methods described above. The results are shown in Table 3.

[0135]

Example 7 A linear polyethylene having the characteristic values shown in Table 3 was prepared in the same manner as in Example 1, and a thickness of 100 was obtained from this linear polyethylene in the same manner as in Example 5.
A film of μm was obtained. About the obtained film, 1
After retort treatment at 15 ° C. for 30 minutes, haze, appearance and Young's modulus were measured or evaluated by the methods described above. The results are shown in Table 3.

[0136]

Comparative Example 5 A film having a thickness of 100 μm was obtained in the same manner as in Example 5, except that the linear polyethylene of Comparative Example 1 was used instead of the linear polyethylene of Example 1. It was About the obtained film, 115
After retort treatment at 30 ° C. for 30 minutes, haze, appearance and Young's modulus were measured or evaluated by the methods described above. The results are shown in Tables 3 and 6.

[0137]

Comparative Example 6 A film having a thickness of 100 μm was obtained in the same manner as in Example 5 except that the linear polyethylene of Comparative Example 2 was used instead of the linear polyethylene of Example 1. It was About the obtained film, 115
After retort treatment at 30 ° C. for 30 minutes, haze, appearance and Young's modulus were measured or evaluated by the methods described above. The results are shown in Tables 3 and 6.

[0138]

[Table 3]

[0139]

Example 8 [Production of film] The linear polyethylene of Example 1 was
A cast film molding machine manufactured by Modern Co., Ltd. was used to mold the film under the conditions of a cylinder temperature of 180 to 220 ° C., a die temperature of 220 ° C., and a roll temperature of 30 ° C. to obtain a film having a thickness of 50 μm. About the obtained film, 115 ° C,
After 30 minutes of retort treatment, haze, appearance and Young's modulus were measured or evaluated by the methods described above. The fourth result
Shown in the table.

[0140]

Example 9 A film having a thickness of 50 μm was obtained in the same manner as in Example 8 except that the linear polyethylene of Example 2 was used instead of the linear polyethylene of Example 1. It was About the obtained film, 115 ° C,
After 30 minutes of retort treatment, haze, appearance and Young's modulus were measured or evaluated by the methods described above. The fourth result
Shown in the table.

[0141]

Example 10 A film having a thickness of 50 μm was obtained in the same manner as in Example 8 except that the linear polyethylene of Example 7 was used instead of the linear polyethylene of Example 1. It was About the obtained film, 115
After retort treatment at 30 ° C. for 30 minutes, haze, appearance and Young's modulus were measured or evaluated by the methods described above. The results are shown in Table 4.

[0142]

Example 11 A linear polyethylene having the characteristic values shown in Table 4 was prepared in the same manner as in Example 1, and a thickness of 50 was obtained from this linear polyethylene in the same manner as in Example 8.
A film of μm was obtained. About the obtained film, 1
After retort treatment at 15 ° C. for 30 minutes, haze, appearance and Young's modulus were measured or evaluated by the methods described above. The results are shown in Table 4.

[0143]

Comparative Example 7 A film having a thickness of 50 μm was obtained in the same manner as in Example 8 except that the linear polyethylene of Comparative Example 1 was used instead of the linear polyethylene of Example 1. It was About the obtained film, 115 ° C,
After 30 minutes of retort treatment, haze, appearance and Young's modulus were measured or evaluated by the methods described above. The fourth result
Shown in the table.

[0144]

Comparative Example 8 A film having a thickness of 50 μm was obtained in the same manner as in Example 8 except that the linear polyethylene of Comparative Example 2 was used instead of the linear polyethylene of Example 1. It was About the obtained film, 115 ° C,
After 30 minutes of retort treatment, haze, appearance and Young's modulus were measured or evaluated by the methods described above. The fourth result
Shown in the table.

[0145]

[Table 4]

[0146]

[Example 12] [Production of hollow molded article] In Example 1, 95 parts by weight of the linear polyethylene of Example 1 and high-density polyethylene [abbreviated as HDPE (a); density = 0.941 g / cm3]
³ , MFR = 2.0 g / 10 minutes, Mw / Mn = 2.4,
Tm = 128 ° C.] A hollow molded article (bottle) was obtained in the same manner as in Example 1 except that a linear polyethylene composition consisting of 5 parts by weight was used. About the obtained hollow molded product, 1
After retort treatment at 15 ° C. for 30 minutes, haze, appearance and Young's modulus were measured or evaluated by the methods described above. The results are shown in Table 5.

[0147]

Example 13 In Example 12, the linear polyethylene and the high density polyethylene of Example 1 [HDPE
A hollow molded article was obtained in the same manner as in Example 12 except that the compounding amounts of (a)] were changed to 90 parts by weight and 10 parts by weight, respectively. The resulting hollow molded article was subjected to retort treatment at 115 ° C. for 30 minutes, and then the haze, appearance and Young's modulus were measured or evaluated by the methods described above. The results are shown in Table 5.

[0148]

Example 14 In Example 12, instead of 5 parts by weight of high-density polyethylene [HDPE (a)], abbreviated as high-density polyethylene [HDPE (b); density = 0.960 g /
cm ³ , MFR = 15 g / 10 min, Mw / Mn = 2.
8, Tm = 132 ° C.] A hollow molded article was obtained in the same manner as in Example 12 except that 5 parts by weight was used. The obtained hollow molded article was subjected to retort treatment at 115 ° C. for 30 minutes,
The haze, appearance and Young's modulus were measured or evaluated by the methods described above. The results are shown in Table 5.

[0149]

[Example 15] In Example 14, the linear polyethylene and the high-density polyethylene [HDPE of Example 1 were used.
A hollow molded article was obtained in the same manner as in Example 14, except that the blending amounts of (b)] were changed to 90 parts by weight and 10 parts by weight, respectively. The resulting hollow molded article was subjected to retort treatment at 115 ° C. for 30 minutes, and then the haze, appearance and Young's modulus were measured or evaluated by the methods described above. The results are shown in Table 5.

[0150]

[Table 5]

[0151]

Example 16 [Production of film] In Example 5, a linear polyethylene comprising 95 parts by weight of the linear polyethylene of Example 1 and 5 parts by weight of the high-density polyethylene [HDPE (a)] of Example 12. A film having a thickness of 100 μm was obtained in the same manner as in Example 5 except that the composition was used. The film obtained was subjected to retort treatment at 115 ° C. for 30 minutes, and then the haze, appearance and Young's modulus were measured or evaluated by the methods described above. The results are shown in Table 6.

[0152]

Example 17 In Example 16, the linear polyethylene and the high-density polyethylene [HDPE of Example 1 were used.
A film having a thickness of 100 μm was obtained in the same manner as in Example 16 except that the compounding amounts of (a)] were changed to 90 parts by weight and 10 parts by weight, respectively. About the obtained film, 115
After retort treatment at 30 ° C. for 30 minutes, haze, appearance and Young's modulus were measured or evaluated by the methods described above. The results are shown in Table 6.

[0153]

Example 18 Example 16 was repeated except that 5 parts by weight of the high-density polyethylene [HDPE (b)] of Example 14 was used in place of 5 parts by weight of the high-density polyethylene [HDPE (a)] in Example 16. A film having a thickness of 100 μm was obtained in the same manner as in. About the obtained film, 115 ° C,
After 30 minutes of retort treatment, haze, appearance and Young's modulus were measured or evaluated by the methods described above. Result 6
Shown in the table.

[0154]

Example 19 In Example 18, the linear polyethylene and the high-density polyethylene [HDPE of Example 1 were used.
A film having a thickness of 100 μm was obtained in the same manner as in Example 18, except that the compounding amounts of (b)] were changed to 90 parts by weight and 10 parts by weight, respectively. About the obtained film, 115
After retort treatment at 30 ° C. for 30 minutes, haze, appearance and Young's modulus were measured or evaluated by the methods described above. The results are shown in Table 6.

[0155]

[Table 6]

[Brief description of drawings]

FIG. 1 is a diagram showing an endothermic curve measured by a differential scanning calorimeter for a linear polyethylene of Example 2 according to the present invention.

FIG. 2 is a diagram showing an endothermic curve of the linear polyethylene of Comparative Example 1 measured by a differential scanning calorimeter.

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Claims (11)

[Claims] 1. A container having a layer composed of linear polyethylene obtained by copolymerizing ethylene and an α-olefin having 3 to 12 carbon atoms, wherein the linear polyethylene has a density (i) of It is in the range of 0.918 to 0.940 g / cm ³ , and (ii) the molecular weight distribution (Mw / Mn: Mw = weight average molecular weight, Mn = number average molecular weight) measured by GPC is 1.5 to 3.0. Within the range, the layer made of the linear polyethylene has (a) a haze of 30% or less after the retort sterilization treatment, and (b) a deformation start temperature (T
d [° C.]) is higher than the sterilization temperature, a retort container. 2. The linear polyethylene is (iii) 23.
When the decane soluble component amount fraction (W [wt%]) and the density (d [g / cm ³ ]) at C are MFR ≦ 10 g / 10 min, W <80 × exp (−100 (d− 0.88)) + 0.1 When MFR> 10 g / 10 min, W <80 × (MFR-9) ^0.26 × exp (−100 (d−
The retort container according to claim 1, wherein the relationship represented by 0.88)) + 0.1 is satisfied. 3. The straight-chain polyethylene comprises ethylene and an α-containing 3 to 12 carbon atoms in the presence of an olefin polymerization catalyst containing a metallocene catalyst component (A) represented by the following general formula [I]. Obtained by copolymerizing with olefin, and (i) density is 0.918 to 0.940 g
/ In the range of cm ^3, (ii) the molecular weight was measured by GPC distribution (Mw / Mn: Mw = weight average molecular weight, Mn =
Number average molecular weight) is in the range of 1.5 to 3.0, (ii
i) The decane-soluble component amount fraction (W [wt%]) and the density (d [g / cm ³ ]) at 23 ° C. are MFR ≦ 10.
When g / 10 minutes, W <80 × exp (−100 (d−0.88)) + 0.1 MFR> 10 g / 10 minutes, W <80 × (MFR-9) ^0.26 × exp (-100 (d-
0.88)) + 0.1 is satisfied, The retort container according to claim 2, ML ¹ _x ... [I] [wherein M is a group IVB group in the periodic table]. L ¹ is a ligand that coordinates to the transition metal atom M, and at least one of these ligands L ¹ is a ligand having a cyclopentadienyl skeleton. The ligand L ¹ other than the ligand having a cyclopentadienyl skeleton is a hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group, an aryloxy group, a trialkylsilyl group, SO ₃ R
(However, R is a hydrocarbon group having 1 to 8 carbon atoms which may have a substituent such as halogen), a halogen atom or a hydrogen atom, and x is a valence of the transition metal atom M. ]. 4. The metallocene catalyst component (A) is represented by the following general formula [II] ML ² _x ... [II] [wherein M is a transition metal atom selected from Group IVB of the periodic table]. And L ² is a ligand that coordinates to the transition metal atom M, and at least two of the ligands L ² are a cyclopentadienyl group, a methylcyclopentadienyl group, and an ethylcyclopenta group. A substituted cyclopentadienyl group having at least one substituent selected from a dienyl group or a hydrocarbon group having 3 to 10 carbon atoms, wherein the ligand L ² other than the (substituted) cyclopentadienyl group is ,
It is a hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group, an aryloxy group, a trialkylsilyl group, a halogen atom or a hydrogen atom, and x is a valence of the transition metal atom M. ] It is a transition metal compound represented by these, The retort container of Claim 3 characterized by the above-mentioned. 5. The retort according to claim 3, wherein the olefin polymerization catalyst comprises a fine particle carrier, a metallocene catalyst component (A), and an organoaluminum oxy compound component (B). container. 6. The olefin polymerization catalyst comprises a fine particle carrier, a metallocene catalyst component (A), an organoaluminum oxy compound component (B), and an organoaluminum compound component (C). The retort container according to claim 3 or 4. 7. The catalyst for olefin polymerization is a particulate carrier, a metallocene catalyst component (A), an organoaluminum oxy compound component (B), an organoaluminum compound component (C), and an ionized ionic compound catalyst component. The retort container according to claim 3 or 4, comprising (D). 8. High-density polyethylene is added to the linear polyethylene in an amount of 5 to 3 relative to 100 parts by weight of the total amount of both components.
The retort container according to any one of claims 1 to 3, which is made of a linear polyethylene composition blended with 0 part by weight. 9. The high-density polyethylene (i) has a density of 0.970 g / cm ³ or less and exceeds 0.940 g / cm ³ , and (ii) a molecular weight distribution measured by GPC (Mw / Mn: The retort container according to claim 8, wherein Mw = weight average molecular weight and Mn = number average molecular weight) are in the range of 1.5 to 4.0. 10. The retort container according to claim 1, which is a medical container. 11. The retort container according to claim 1, which is a food container.