JP3907025B2 - Bulk container liner film and container liner - Google Patents

Description

【００５６】
【実施例２】
実施例１と同様にして得た直径約１５３０ｍｍ、厚さ１２０μｍのインフレーションフィルムをガゼット折りし、折り畳み幅２４２０ｍｍの平坦フィルムを得た。このフィルムを長さ約８３００ｍｍに切断し、両端を折り畳んで、フィルムの重なり部分をヒートシールし、長さ約５９００ｍｍ、幅約２５００ｍｍ、高さ約２４００ｍｍの直方体となる形状にした。この直方体の一方の端部に被内容物の供給口および排出口をヒートシールによって設けた。
【００５７】
このフィルムをコンテナーに収め、圧縮空気を吹き込んでコンテナーの内壁形状に沿った形へと膨らませて直方体形状のライナーとし、その内に約８０℃の高純度テレフタール酸を投入したところ、作業効率よく充填することができた。
【図面の簡単な説明】
【図１】図１は、本発明に係るバルクコンテナーライナー用フィルムをガゼット折りした時の概略断面図を示す。
【図２】図２は、本発明に係るバルクコンテナーライナーの一実施例の斜視図を示す。
【符号の説明】
１ ・・・ フィルム
２ ・・・ ガゼット折り部
３ ・・・ ヒートシール部
４ ・・・ 供給口
５ ・・・ 排出口
６ ・・・ ヒートシール部
７ ・・・ ライナー[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a film for a liner attached to a container used for bulk transportation, and more particularly, in the transportation and storage of granular or powdered chemical substances, synthetic resins, sugars, grains and other foods. It is related with the film used for manufacture of the liner (inner bag) of a bulk container used.
[0002]
The present invention also relates to the aforementioned bulk container liner (BCL).
[0003]
TECHNICAL BACKGROUND OF THE INVENTION
Films for bulk container liners are usually manufactured in a cylindrical shape by the inflation molding method of synthetic resin, and the shape of the container is generally a rectangular parallelepiped, so both ends are sealed according to the dimensions of the inner shape of the container, made into a bag shape and liner It becomes. This liner is folded and stored by gusset folding. By this gusset folding, a crease is formed in the cylindrical film. The fold is called a gusset fold. The film part other than the gusset crease part is generally called a raw film part.
[0004]
Conventionally, as a liner film for a large bulk container such as 20 feet (about 6.1 m) or 40 feet (about 12.2 m), for example, an ethylene / vinyl acetate copolymer having a vinyl acetate content of 1 to 5%. Single-layer or multi-layer films having a thickness of about 140 μm to 200 μm have been used.
[0005]
When containing contents such as foods such as granular or powdered chemical substances, sugar, grains, etc. in the bulk container liner, it is usually heat-sealed between the overlapping films at both ends to form a seal on the liner It was. However, in conventional bulk container liner films, the adhesive strength of the heat seal part is not always sufficient, so there is still concern over use, so as a countermeasure, stick an adhesive tape on the heat seal part to attach the heat seal part. It was being reinforced. Moreover, since the thickness of the film is as thick as about 140 μm and the weight of the liner is large, it is not easy to attach the liner into the bulk container. Furthermore, since the melting point of the film is about 90 ° C., the content in the high temperature state cannot be accommodated in the liner at the same temperature in the liner made of the film, and the temperature of the content is For example, the filling operation was performed after cooling to 50 ° C. or lower.
[0006]
As described above, problems in use have been pointed out to the bulk container liner and the liner film that have been used so far, and improvement has been desired.
[0007]
OBJECT OF THE INVENTION
The present invention is to solve the problems associated with the prior art as described above, and it is possible to reduce the weight of the liner by thinning the film, and the adhesive tape on the heat seal portion. It is intended to provide a film for bulk container liners that exhibits high heat seal strength that does not break even if it is not attached, and has heat resistance that allows the contents to be filled at a higher temperature than before. It is aimed.
[0008]
Another object of the present invention is to provide a liner for a bulk container that is lightweight, has a heat seal portion with high adhesive strength, and can be filled at a high temperature.
[0009]
SUMMARY OF THE INVENTION A film for a bulk container liner according to the present invention is a film made of polyethylene (A) prepared using a single site olefin polymerization catalyst, and the polyethylene (A) has (i) a density of 0. .920-0.940 g / cm^Three (Ii) Melt flow rate (ASTM D 1238, 190 ° C., load 2.16 kg) is 0.1 to 3.0 g / 10 min. (Iii) Melting point (Tm) is 115 to 135 ° C.Yes, when the film is heat-sealed, the tensile strength at break (Ts) at the seal portion is 2.0 to 4.0 kg / 15 mm, and the tensile elongation at break (EL) is 150 to 600%. is thereIt is characterized by that.
[0010]
The bulk container liner according to the present invention is characterized in that an inflation film made of the polyethylene (A) prepared using a single site olefin polymerization catalyst is formed into a bag shape.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Next, the film for a bulk container liner and the liner for a bulk container according to the present invention will be specifically described.
[0012]
The film for a bulk container liner according to the present invention is a film made of polyethylene (A).
(1) Polyethylene (A)
The polyethylene (A) used in the present invention is an ethylene homopolymer prepared using a single-site olefin polymerization catalyst, or ethylene and an α-olefin having 3 to 20 carbon atoms in the presence of a single-site olefin polymerization catalyst. Is an ethylene / α-olefin copolymer obtained by copolymerization of The molecular structure of the ethylene homopolymer and the ethylene / α-olefin copolymer may be branched or linear.
[0013]
Specific examples of the α-olefin having 3 to 20 carbon atoms used for copolymerization with ethylene include propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1- Examples include octene, 1-decene, and 1-dodecene. Among these, α-olefins having 3 to 10 carbon atoms, particularly α-olefins having 4 to 8 carbon atoms are preferable. The α-olefins as described above can be used alone or in combination of two or more.
[0014]
In the ethylene / α-olefin copolymer used in the present invention, the structural unit derived from ethylene is 50 wt% or more and less than 100 wt%, preferably 75 to 99 wt%, more preferably 75 to 95 wt%, particularly preferably. Is present in an amount of 83 to 95% by weight, and the structural unit derived from the α-olefin having 3 to 20 carbon atoms is 50% by weight or less, preferably 1 to 25% by weight, more preferably 5 to 25% by weight, It is particularly desirable that it be present in an amount of 5 to 17% by weight.
[0015]
The repeating unit or monomer component constituting polyethylene (A) is usually a solution of about 200 mg of polyethylene (A) uniformly dissolved in 1 ml of hexachlorobutadiene in a 10 mmφ sample tube.¹³The C-NMR spectrum is determined by measurement under the conditions of a measurement temperature of 120 ° C., a measurement frequency of 25.05 MHz, a spectrum width of 1500 Hz, a pulse repetition time of 4.2 sec., And a pulse width of 6 μsec.
[0016]
The polyethylene (A) used in the present invention has a density (ASTM D 1505) of 0.920 to 0.940 g / cm.^Three , Preferably 0.922 to 0.938 g / cm^ThreeMore preferably, 0.924-0.935 g / cm^Three It is. When polyethylene (A) having a density in the above range is used, a film having excellent heat seal strength characteristics can be obtained. Therefore, a part of the conventional liner manufacturing process or filling the contents, which is to stick the adhesive tape on the heat seal part as conventionally performed to reinforce the heat seal part, Can be omitted.
[0017]
Further, the melt flow rate (ASTM D 1238, 190 ° C., load 2.16 kg) of this polyethylene (A) is 0.1 to 3.0 g / 10 min, preferably 0.3 to 2.0 g / 10 min, more preferably Is in the range of 0.5 to 1.0 g / 10 min. Polyethylene (A) having a melt flow rate in the above range is excellent in film formability by the inflation molding method while being air-cooled. That is, the resin extrudability at the time of inflation is good, the bubbles are stable, and a film without rough skin can be formed at a high speed.
[0018]
The polyethylene (A) used in the present invention has a melting point (Tm) in the range of 115 to 135 ° C, preferably 117 to 135 ° C, for example, in order to fill the liner with a chemical substance produced at a high temperature. When polyethylene (A) having a melting point within the above range is used, a bulk container liner capable of filling the contents of the container at a higher temperature than before can be obtained. By the way, even if the contents in a high temperature state immediately after manufacture are not cooled to a low temperature as required for a conventional liner as in the prior art, that is, if cooled to about 80 ° C., for example, The contents can be filled in the liner in a state. On the other hand, the conventional liner could not be filled without cooling the contents to about 50 ° C. As a result, the cooling time of the contents can be shortened, and the filling operation time of the contents into the liner is shortened as a whole and the efficiency is improved.
[0019]
The melting point (Tm) here is the temperature at the maximum peak position of the endothermic curve measured by a differential scanning calorimeter (DSC), about 5 mg of a sample is packed in an aluminum pan and heated up to 200 ° C. at 10 ° C./min. It is obtained from an endothermic curve when it is held at 200 ° C. for 5 minutes, then cooled to room temperature at 20 ° C./minute, and then heated at 10 ° C./minute. The measurement uses a DSC-7 type apparatus manufactured by PerkinElmer.
[0020]
Furthermore, the polyethylene (A) used in the present invention is a ratio (Mw / Mw) of weight average molecular weight (Mw) and number average molecular weight (Mn) measured by GPC at a column temperature of 140 ° C. using o-dichlorobenzene as a carrier. Mn) is preferably 1.5 to 4.0, particularly 1.5 to 3.5. The value of Mw / Mn is an index showing the spread of molecular weight distribution, and polyethylene (A) in the above range shows that the molecular weight distribution is narrow, and a tough film excellent in impact resistance can be obtained. At the same time, a film having a good appearance with no rough skin can be obtained. In addition, since the low molecular weight component is small, the low molecular weight component bleeds out from the film, and there is little risk of contaminating the contents to be filled in the liner. It can be stored well until it is used as a liner, and it is also convenient when a folded liner is inflated before filling the contents.
[0021]
Polyethylene (A) as described above is described in single site olefin polymerization catalysts such as USP 5,459,217, USP 5,371,146, JP-A-6-136196, USP 5,464,905, and the like. In the presence of a so-called metallocene olefin polymerization catalyst containing a metallocene catalyst component, or in the presence of a Brookhardt catalyst, ethylene is homopolymerized or ethylene and an α-olefin having 3 to 20 carbon atoms are produced. It can be produced by copolymerization.
[0022]
The metallocene-based catalyst is usually a metallocene catalyst component (a) composed of a transition metal compound of Group IVB of the periodic table having at least one ligand having a cyclopentadienyl skeleton, an organoaluminum oxy compound catalyst component ( b), a particulate carrier (c), and optionally an organoaluminum compound catalyst component (d) and an ionized ionic compound catalyst component (e).
[0023]
Examples of the metallocene catalyst component (a) preferably used in the present invention include Group IVB transition metal compounds having at least one ligand having a cyclopentadienyl skeleton. Examples of such a transition metal compound include a transition metal compound represented by the following general formula [I].
[0024]
ML¹x ... [I]
In the formula, x is the valence of the transition metal atom M.
M is a transition metal atom selected from Group IVB of the periodic table, and specifically, zirconium, titanium, and hafnium. Of these, zirconium is preferable.
[0025]
L¹ Is a ligand coordinated to the transition metal atom M, of which at least one ligand L¹Is a ligand having a cyclopentadienyl skeleton.
Ligand L having cyclopentadienyl skeleton coordinated to transition metal atom M as described above¹Specifically, alkyl-substituted cyclopenta such as cyclopentadienyl group, methylcyclopentadienyl group, dimethylcyclopentadienyl group, methylethylcyclopentadienyl group, n-butylcyclopentadienyl group, etc. Examples thereof include a dienyl group, an indenyl group, a 4,5,6,7-tetrahydroindenyl group, a fluorenyl group, and the like. These groups may be substituted with a halogen atom, a trialkylsilyl group or the like.
[0026]
When the compound represented by the general formula [I] includes two or more groups having a cyclopentadienyl skeleton, the groups having two cyclopentadienyl skeletons are alkylene groups such as ethylene and propylene. And may be bonded via a substituted silylene group such as a silylene group or a dimethylsilylene group, a diphenylsilylene group, and a methylphenylsilylene group.
[0027]
As the organoaluminum oxy compound catalyst component (b), aluminoxane is preferably used. Specifically, the formula
-Al (R) O- [wherein R is an alkyl group]
In general, methylaluminoxane, ethylaluminoxane, methylethylaluminoxane, or the like having about 3 to 50 repeating units is used. These may be benzene soluble or insoluble.
[0028]
The particulate carrier (c) used in the preparation of the olefin polymerization catalyst is an inorganic or organic compound and has a particle size of usually about 10 to 300 μm, preferably 20 to 200 μm in a granular or particulate solid. It is. The inorganic carrier is preferably a porous oxide, specifically SiO.₂, Al₂O_Three, MgO, ZrO₂TiO₂ Etc. can be illustrated.
[0029]
Specific examples of the organoaluminum compound catalyst component (d) used as necessary in the preparation of an olefin polymerization catalyst include trialkylaluminums such as trimethylaluminum, triethylaluminum, and triisobutylaluminum, and dialkyls such as dimethylaluminum chloride. Examples thereof include aluminum halides and alkylaluminum sesquihalides such as methylaluminum sesquichloride.
[0030]
Examples of the ionized ionic compound catalyst component (e) used as necessary include triphenylboron and MgCl described in USP-5,321,106.₂, Al₂O_Three, SiO₂-Al₂O_Three Lewis acids such as: ionic compounds such as triphenylcarbenium tetrakis (pentafluorophenyl) borate; carborane compounds such as dodecaborane and bis n-butylammonium (1-carbedodeca) borate.
[0031]
The polyethylene (A) used in the present invention is a homopolymerization of ethylene or ethylene under various conditions in the gas phase or slurry or solution liquid phase in the presence of the olefin polymerization catalyst as described above. And an α-olefin having 3 to 20 carbon atoms can be copolymerized. For example, at a polymerization temperature of −50 to 100 ° C. in a slurry polymerization method, −50 to 500 ° C. in a solution polymerization method, and 0 to 120 ° C. in a gas phase polymerization method, normal pressure to 100 kg / cm²Can be produced under the following pressures.
[0032]
The obtained copolymer has a linear molecular structure or a short chain branch or a long chain branch in the main chain depending on the production conditions, particularly the kind of the polymerization catalyst.
In film forming, other polyolefins such as high-pressure low-density polyethylene can be appropriately blended. In particular, in order to increase the film extrudability and also to increase the rigidity and strength, blending 80 to 100% by weight of polyethylene (A) with 20 to 0% by weight of low density polyethylene produced by the high-pressure radical polymerization method It is effective. The high-pressure low-density polyethylene has a density of 0.915 to 0.924 g / cm.^ThreePolyethylene having an MFR of 0.1 to 2.0 g / 10 min is preferable.
[0033]
Furthermore, an antioxidant, a heat stabilizer, a weather stabilizer, an antistatic agent, a filler, a slip agent and the like can be appropriately blended with the polyethylene (A) as long as the object of the present invention is not impaired.
[0034]
(2) Film and liner
The film for a bulk container liner according to the present invention is a film formed from the above-mentioned polyethylene (A) by an inflation molding method, and is preferably gusset-folded for producing a folded liner. That is, polyethylene (A) is supplied to an inflation film molding machine equipped with a screw having a low compression ratio in the compression zone and equipped with a single screw extruder suitable for molding linear low density polyethylene (L-LDPE). A cylindrical bubble-like film is continuously formed by extruding from a circular die under extrusion conditions of 160 to 220 ° C. and air-cooling from the outside while inflating with air pressure. Before the bubble-shaped film is sandwiched between a pair of pinch rolls, the pair of gussets are pressed against the bubble from the left and right sides of the bubble, and the film is folded into a flat plate with a pinch roll. It is wound up. FIG. 1 is a schematic cross-sectional view of a liner film that has been gusset-folded, and shows a state in which an inflation-formed film 1 is gusset-folded from the diameter direction toward the center to form a gusset fold 2. .
[0035]
This gusset-folded film is cut to a predetermined length so as to have a dimension larger than the length of the container, and then both ends are sealed to form a liner. FIG. 2 shows a perspective view of the liner. Both ends in the length direction of the film are folded, and the overlapping portions of the film are usually heat-sealed at 130 to 200 ° C. and bonded to each other to form the heat seal portion 3. . By forming the heat seal portions 3 at both ends of the film, the cylindrical film has a bag-like sealing structure. Further, the supply port 4 for filling the contents at one end and the discharge port 5 for discharging the contents are similarly heat-sealed and fixed to the film to form the heat seal portion 6. In this way, the supply port 4 and the discharge port 5 are provided, and the liner 7 is completed.
[0036]
The thickness of the film for the bulk container liner according to the present invention is appropriately determined depending on the size of the bulk container to be used, the type of contents to be accommodated in the liner, the weight, etc. Usually, it is 100-200 micrometers.
[0037]
And this film for a liner is formed into a shape as a liner, accommodated in a container, and filled with the contents, it may have the following physical properties according to its usage mode desirable. If each numerical value is within the range, the film has the mechanical properties required for a bulk container liner and can be used conveniently.
(1) Film having a tensile breaking strength (Ts) of 2.0 to 4.0 kg / 15 mm and a tensile breaking elongation (EL) of 150 to 600% when heat-sealed. Is preferred.
(2) In particular, when the film is gusset-folded, the tensile strength at break (Ts) in the raw film portion is 4.0 to 9.0 kg / 15 mm in the MD direction and 4.0 to 8.0 in the TD direction. 0 kg / 15 mm, the tensile elongation at break (EL) is 300 to 900% in the MD direction, 300 to 800% in the TD direction, the dart impact strength is 700 g or more, and
The tensile strength at break (Ts) at the fold portion is 3.5 to 8.5 kg / 15 mm in the MD direction and 3.5 to 8.5 kg / 15 mm in the TD direction, and the tensile elongation at break (EL) is EL. A film having 300 to 800% in the MD direction and 300 to 800% in the TD direction and a dart impact strength of 650 g or more is preferable.
[0038]
【The invention's effect】
The bulk container liner film according to the present invention is prepared by using a single-site olefin polymerization catalyst as described above and formed of polyethylene (A) having a specific density, melt flow rate and melting point. Therefore, it has excellent mechanical strength properties such as tensile strength at break (Ts) and dirt impact strength at the original film portion, tensile strength at break (Ts) at the crease portion, and tensile strength (Ts) at the seal portion. ing. In particular, the strength of the gusset crease is maintained at a higher value than that of the existing polyethylene or ethylene-vinyl acetate copolymer film.
[0039]
Therefore, according to the present invention, the thickness of the bulk container liner film can be reduced by a thickness that is further superior to the thickness of the conventional bulk container liner film, for example, 140 μm, for example, 100 to 100 μm. The thickness can be 120 μm. As a result, the bulk container liner according to the present invention can be made lighter than conventional bulk container liners, and the workability and work efficiency of installing the liner into the bulk container are improved by reducing the weight. In addition, when the used liner is discarded as much as the thickness of the film can be reduced, there is an advantage that the amount of waste is reduced.
[0040]
According to the present invention, it is possible to reduce the thickness of the film and reduce the weight of the liner, and since the heat seal strength between the films is high, the adhesive tape is purposely placed on the place where the films are heat sealed. Even without sticking, the liner filled with the contents is strong enough not to break. Further, it is possible to provide a bulk container liner that can be filled even when the contents are not sufficiently cooled as compared with the conventional filling temperature, that is, at a higher temperature than the conventional one.
[0041]
In addition, according to the present invention, a lightweight liner having high mechanical strength is provided, the attachment work to the container is easy, and the contents can be filled at a higher temperature than before, so the ease of use of the liner is increased. be able to.
[0042]
【Example】
EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to an Example.
[0043]
In addition, the measurement of the physical property etc. of the film in an Example and a comparative example was performed by the following method.
(1) Tensile strength at break (Ts) and tensile elongation at break (EL)
Tensile tests are performed using a constant crosshead moving speed type tensile tester (manufactured by Instron) in the MD direction and the TD direction in the original film part and the crease part of the gusset-folded film, and the tensile strength at each breaking point. (Ts) and tensile elongation at break (EL) were measured.
[Test conditions]
Sample: Prepared according to JIS Z1707.
Atmospheric temperature: 23 ° C
Pulling speed: 300mm / min
[0044]
(2) Tensile strength at break (Ts) and tensile elongation at break (EL)
After sealing the film with New Long HS-33D Top Sealer (trade name, manufactured by Tester Sangyo Co., Ltd.) (sealing condition: 160 ° C.) A tensile test (JIS Z1707) was performed to measure the tensile strength at break (Ts; seal strength).
(3) Dirt impact strength
The value measured according to the ASTM D 1709B method was divided by the thickness of the film, and the value was defined as the dart impact strength (g / mm), and the dart impact strength at the original film portion and the fold portion of the gusset-folded film was obtained. .
[0045]
[Reference Example 1]
[Preparation of Olefin Polymerization Catalyst]
After 6.3 kg of silica dried at 250 ° C. for 10 hours was suspended in 100 liters of toluene, it was cooled to 0 ° C. Thereafter, 41 liters of a toluene solution of methylaluminoxane (Al; 0.96 mol / liter) was dropped into the suspension over 1 hour. At this time, 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. Thereafter, the temperature was lowered to 60 ° C., and the supernatant was removed by a decantation method.
[0046]
The solid component thus obtained was washed twice with toluene and then resuspended in 125 liters of toluene. To this system, 15 liters of a toluene solution of bis (n-butylcyclopentadienyl) zirconium dichloride (Zr; 42.7 mmol / liter) was added dropwise at 30 ° C. over 30 minutes, and further reacted at 30 ° C. for 2 hours. It was. Thereafter, the supernatant was removed and washed twice with hexane to obtain a solid catalyst containing 6.2 mg of zirconium per 1 g.
[0047]
[Preparation of prepolymerization catalyst]
By adding 8.5 kg of the solid catalyst obtained above to 300 liters of hexane containing 14 mol of triisobutylaluminum, and preliminarily polymerizing ethylene at 35 ° C. for 7 hours, 3 g of polyethylene per 1 g of the solid catalyst was obtained. A prepolymerized prepolymerized catalyst was obtained.
[0048]
[Ethylene polymerization]
Using a continuous fluidized bed gas phase polymerization apparatus, copolymerization of ethylene and 1-hexene was performed in the presence of the prepolymerization catalyst.
[0049]
The polyethylene (PE-1) thus obtained has a 1-hexene unit content of 9.5% by weight and a density (ASTM D 1505) of 0.930 g / cm.^Three The melt flow rate (ASTM D 1238, 190 ° C., load 2.16 kg) was 0.9 g / 10 min, and the melting point (Tm) measured by DSC was 129 ° C. Moreover, Mw / Mn was 3.5.
[0050]
[Example 1]
The polyethylene obtained in Reference Example 1 was pelletized with an extruder, and then molded using an air-cooled inflation film molding apparatus under the following molding conditions to produce a film having a thickness of 120 μm.
[0051]
[Molding condition]
Molding machine: 150mmφ blown film molding machine manufactured by Dolch
Screw: L / D = 32
Dies: 1500mmφ (diameter), 2.5mm (lip width)
Air ring: 2 gap type
Molding temperature: 180 ° C
Take-off speed: 10m / min
The tensile break strength (Ts), tensile break elongation (EL), and dart impact strength at the film original fabric portion and the fold portion of the film obtained as described above were measured according to the above methods. Moreover, the tensile breaking point strength (Ts) and the tensile breaking point elongation (EL) in the seal part of this film were measured according to the above methods.
[0052]
The results are shown in Table 1.
[0053]
[Comparative Example 1]
Tensile strength at break (Ts) and tensile elongation at break in the original and fold portions of the gusset-folded film of a 140 μm-thick bulk container liner film produced from the ethylene-vinyl acetate copolymer currently used The degree (EL) and the dart impact strength were measured according to the methods described above. Moreover, the tensile breaking point strength (Ts) and the tensile breaking point elongation (EL) in the seal part of this film were measured according to the above methods.
[0054]
The results are also shown in Table 1.
[0055]
[Table 1]

[0056]
[Example 2]
An inflation film having a diameter of about 1530 mm and a thickness of 120 μm obtained in the same manner as in Example 1 was gusset-folded to obtain a flat film having a folding width of 2420 mm. This film was cut to a length of about 8300 mm, both ends were folded, and the overlapping portions of the film were heat sealed to form a rectangular parallelepiped having a length of about 5900 mm, a width of about 2500 mm, and a height of about 2400 mm. The supply port and the discharge port for the contents were provided by heat sealing at one end of the rectangular parallelepiped.
[0057]
When this film is placed in a container and compressed air is blown into a shape that conforms to the shape of the inner wall of the container to form a rectangular parallelepiped liner, high-purity terephthalic acid at approximately 80 ° C is charged into the liner. We were able to.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view when a bulk container liner film according to the present invention is gusset-folded.
FIG. 2 shows a perspective view of one embodiment of a bulk container liner according to the present invention.
[Explanation of symbols]
1 ... Film
2 ... Gazette folding part
3 ・ ・ ・ Heat seal part
4 ... Supply port
5 ・ ・ ・ Discharge port
6 ・ ・ ・ Heat seal part
7 ・ ・ ・ Liner

Claims (6)

A film made of polyethylene (A) prepared using a single-site olefin polymerization catalyst,
The polyethylene (A) has (i) a density of 0.920 to 0.940 g / cm ³ , and (ii) a melt flow rate (ASTM D 1238, 190 ° C., load 2.16 kg) of 0.1 to 3 0.0 g / 10 min, (iii) the melting point (Tm) is 115 to 135 ° C. ,
When the film is heat-sealed, the tensile strength at break (Ts) at the seal portion is 2.0 to 4.0 kg / 15 mm, and the tensile elongation at break (EL) is 150 to 600%. A film for bulk container liners.   The polyethylene (A) is an ethylene / α-olefin copolymer having an ethylene content of 75 to 99% by weight and an α-olefin content of 3 to 20 carbon atoms of 25 to 1% by weight. Item 6. A film for a bulk container liner according to Item 1.   2. The film for a bulk container liner according to claim 1, wherein the film comprises 80 to 100% by weight of an ethylene / α-olefin copolymer and 20 to 0% by weight of a high-pressure method low density polyethylene.   When the film is gusset-folded, the tensile strength at break (Ts) in the original film portion is 4.0 to 9.0 kg / 15 mm in the MD direction and 4.0 to 8.0 kg / 15 mm in the TD direction. Yes, the tensile elongation at break (EL) is 300 to 900% in the MD direction, 300 to 800% in the TD direction, the dart impact strength is 700 g / mm or more, and the tensile breaking point at the fold portion The strength (Ts) is 3.5 to 8.5 kg / 15 mm in the MD direction, 3.5 to 8.5 kg / 15 mm in the TD direction, and the tensile elongation at break (EL) is 300 to 800 in the MD direction. The film for bulk container liners according to claim 1, wherein the film has a dart impact strength of 650 g / mm or more. A liner in which an inflation film made of polyethylene (A) prepared using a single-site olefin polymerization catalyst is formed into a bag shape, and the polyethylene (A) has a density (i) of 0.920 to 0.940 g / cm. is ^3, (ii) a melt flow rate (ASTM D-1238,190 ℃, load 2.16 kg) is 0.1 to 3.0 g / 10 min, (iii) the melting point (Tm) is 115 to 135 ° C. is the
When the film is heat-sealed, the tensile strength at break (Ts) at the seal portion is 2.0 to 4.0 kg / 15 mm, and the tensile elongation at break (EL) is 150 to 600%. A liner for bulk containers. A cylindrical blown film that has a rectangular parallelepiped bag shape that is gusset-folded from the diameter direction toward the center, sealed at both ends in the length direction, and is provided with a supply port and a discharge port for contents A liner for a container, the liner being prepared using a single site olefin polymerization catalyst, (i) having a density of 0.920 to 0.940 g / cm ³ and (ii) a melt flow rate (ASTM D -1238, 190 ° C, load 2
. 16 kg) is 0.1 to 3.0 g / 10 min, and (iii) a melting point (Tm) of 115 to 135 ° C. polyethylene (A) ,
When the film is heat-sealed, the tensile strength at break (Ts) at the seal portion is 2.0 to 4.0 kg / 15 mm, and the tensile elongation at break (EL) is 150 to 600%. A liner for bulk containers.

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