KR100250567B1 - Method For Transporting Fluent Material Using Polyethylene Resin Inner Container For Bag in Box - Google Patents

Abstract

The method of repeatedly transporting the fluid according to the present invention

a) in the first position

(i) the blocking force is not more than 1.0 g / cm;

(ii) the number of pinholes formed on an area of 20.5 cm x 28.0 cm after repeated twisting 2,000 times in a film using a gelbo bending tester was 2 or less;

(iii) a flexible, thin-walled flexible interior container made of polyethylene resin made of an ethylene-based copolymer having a bending count of 90,000 or more, measured according to JIS P-8115;

b) unfolding the inner container and containing it in a sufficiently strong portable outer container to form a boxed bag;

c) filling the inner container with fluid, and sealing the inner and outer containers to prevent leakage of the fluid contained in the inner bag;

d) conveying a boxed back container filled in a second position away from the first position;

e) opening the exterior and interior containers to empty the flow material of the interior containers for use in the second position;

f) removing the empty inner container from the outer container;

g) after folding the inner container together, the folded inner container is transported from the second position to the first position or the third position;

h) repeating steps b) to g);

Steps b) to g) can be used repeatedly, for example, about 90,000 times without replacing the flexible built-in container, so that the storage and transportation costs are low.

Description

Method for Transporting Fluent Material Using Polyethylene Resin Inner Container For Bag in Box}

The present invention relates to a method of transporting a fluid material using a soft and thin walled polyethylene resin inner container contained in another container. In particular, the present invention relates to a method of transporting a fluid material using a box-type polyethylene resin built-in container for a bag that can prevent pinholes and ruptures generated when folded and does not separate the heat-adhesive portion.

A container consisting of an outer box such as a corrugated box and a synthetic inner bag housed therein is called a 'bag in box'. These containers have been conventionally used as containers for various liquids, such as liquor, vinegar, photographic developer, bleach, and sterilization liquid, because of their excellent flexibility and economic effect.

The light and thin walled box-type synthetic container for bags is manufactured as follows. That is, melt-extruded synthetic resin; Immediately thereafter the two halves of the container are formed by compression molding; Vacuum forming or blow molding using a mold capable of joining two halves of the resulting container along a diagonal; These halves are then joined either simultaneously or simultaneously.

The box-type bag manufactured as described above in consideration of transportation efficiency and handling property is normally folded state, that is, one half of each container is folded on the other half.

Synthetic resins used in the manufacture of these interior containers require not only high melt tension and good formability, but also provide membranes with a high folding strength that can prevent pinholes and fractures from folding.

In order to meet such demands, in particular, in order to maintain foldability, a polyethylene resin composition in which an ethylene / vinyl acetate copolymer (EVA) or EVA or a high pressure low density polyethylene is blended with a linear polyethylene is conventionally used as a resin for the inner container of a boxed bag. Used.

However, if only EVA is used, only the inner container having good folding property but poor pinhole resistance and bending resistance is obtained. Interior container produced using only conventional linear polyethylene has good pinhole resistance, but poor moldability. In the case of the polyethylene resin composition in which EVA or high pressure low density polyethylene is mixed with linear polyethylene, since a large amount of EVA or high pressure low density polyethylene must be added to the linear polyethylene in order to improve moldability, pinhole resistance and flex resistance are poor.

Since the low density polyethylene produced by the high pressure radical polymerization method has a higher melt tension than the ethylene copolymer produced using the Ziegler catalyst, such polyethylene is used in a film or a hollow container. However, high pressure low density polyethylene is not only low in mechanical strength such as tensile strength, breaking strength or impact strength, but also poor in heat resistance and stress rupture resistance.

Japanese Patent Application Laid-Open Nos. 56-90810 and 60-106806 disclose methods for improving moldability by improving the melt tension or expansion ratio (die / expansion ratio) of ethylene copolymers obtained using Ziegler catalysts, especially titanium catalysts. It is proposed.

However, ethylene-based copolymers (particularly low-density ethylene-based copolymers) obtained by using a titanium catalyst have a wide compositional distribution or have a problem in that moldings such as films are sticky.

Among the ethylene copolymers prepared using the Ziegler catalyst, the ethylene copolymers obtained using the chromium catalyst have a relatively high melt tension but poor thermal stability. The reason is considered to be that the chain terminal of the ethylene-based copolymer prepared using the chromium catalyst tends to become an unsaturated bond.

Ethylene-based copolymers obtained by using a metallocene catalyst, which is a kind of Ziegler catalyst, have a narrow compositional distribution, and the molded product is hardly tacky, so it is rarely disturbed by blocking. Japanese Unexamined Patent Publication No. 60-35007 discloses that an ethylene copolymer obtained by using a zirconocene compound catalyst composed of a cyclopentadienyl derivative contains one terminal unsaturated bond per molecule. It is considered that thermal stability is poor, as in the above ethylene copolymer prepared using a chromium catalyst. In addition, these ethylene copolymers have a poor molecular weight distribution, and thus have poor fluidity during extrusion.

Therefore, it is of great industrial value to develop an ethylene copolymer having high melt tension, low stress in high shear region, good thermal stability, high mechanical strength and narrow compositional distribution.

Japanese Patent Application Laid-open No. Hei 4-189769 proposes a box-type bag interior container formed of a linear polyethylene and a low density polyethylene resin blend having a weight ratio of 55/45 to 65/35. According to this publication, the produced interior container is described that the resin is firmly fused at the welded portion, so that it is not separated and the fold resistance of the container is also good. Although the box-type inner container for containers proposed in this publication has good moldability, since 35% by weight of low-density polypropylene is blended with linear polyethylene, there is a problem of severe pinfolding or rupture.

Under such circumstances, the present inventors have studied diligently and are a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms, and have a specific density, a specific melt flow rate (MFR), and a differential scanning calorimeter (DSC). It was found that the ethylene-based copolymer having a specific relationship between the temperature (melting point, Tm) at the maximum peak position of the measured endothermic curve and the density (d) has excellent thermal stability and narrow compositional distribution. In addition, the present inventors have found that polyethylene resin made of an ethylene copolymer has good moldability, and by forming a box-type bag-containing interior container with this resin, it is possible to remarkably prevent rupture caused by pinholes or folding. Based on such a finding, the present invention has been achieved.

The present invention has been made to solve the conventional problems as described above, an object of the present invention is to form a polyethylene resin with a good moldability, the polyethylene resin for box type bag having excellent blocking resistance, pinhole resistance, bending resistance The present invention provides a method of transporting a fluid material using a built-in container.

The inner bag made of polyethylene resin for box type bag according to the present invention is formed of a polyethylene resin of an ethylene copolymer [A] having the following physical properties:

(i) copolymer [A] is a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms;

(ii) the density ranges from 0.880 to 0.960 g / cm ³ ;

(iii) melt flow rate (MFR, ASTM D 1238-65T, 190 ° C., load 2.16 kg) in the range of 0.01-20 g / 10 min;

(iv) Temperature (Tm) (° C) and density (d) (g / cm ³ ) of the maximum peak position of the endothermic curve measured by differential scanning calorimeter (DSC) satisfy the relation Tm <400 × d-250. .

The ethylene copolymer [A] is preferably a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms in the presence of a metallocene catalyst.

The polyethylene resin-containing container for a bag type bag according to the present invention is preferably formed of a film having the following physical properties.

(i) the blocking force is 1.0 g / cm or less;

(ii) the number of pinholes formed on an area of 20.5 cm x 28.0 cm after 2,000 twisting cycles using a Gelbo flexure tester was 2 or less;

(iii) The number of bends measured in accordance with JIS P-8115 is 90,000 or more.

The reusable packaging container for storing and transporting fluids according to the present invention includes a rigid outer container;

It is housed in an outer container, characterized in that it is a soft, thin-walled flexible inner container that can store and store the flow material,

The interior container is made of polyethylene resin having a thickness of about 30 ~ 1000μm,

(i) the blocking force is 1.0 g / cm or less;

(ii) the number of pinholes formed on an area of 20.5 cm x 28.0 cm after repeated twisting 2,000 times in a film using a gelbo bending tester was 2 or less;

(iii) the number of flexion times before rupture measured in accordance with JIS P-8115 is 90,000 or more, i.e., the filling material is filled in the inner container, and after the emptying, the folding operation is repeated about 90,000 times so that failure does not occur. ;

The polyethylene resin is an ethylene copolymer [A] having the following physical properties;

(i) copolymer [A] is a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms;

(ii) the density ranges from 0.880 to 0.960 g / cm ³ ;

(iii) melt flow rate (MFR, ASTM D 1238-65T, 190 ° C., load 2.16 kg) in the range of 0.01-20 g / 10 min;

(iv) Temperature (Tm) (° C) and density (d) (g / cm ³ ) of the maximum peak position of the endothermic curve measured by differential scanning calorimeter (DSC) satisfy the relation Tm <400 × d-250. .

The method of repeatedly transporting a fluid using the above container

a) in the first position

(i) the blocking force is 1.0 g / cm or less;

(ii) the number of pinholes formed on an area of 20.5 cm x 28.0 cm after repeated twisting 2,000 times in a film using a gelbo bending tester was 2 or less;

(iii) a flexible, thin-walled flexible interior container made of polyethylene resin made of an ethylene-based copolymer having a bending count of 90,000 or more, measured according to JIS P-8115;

b) unfolding the inner container and containing it in a sufficiently strong portable outer container to form a boxed bag;

c) filling the inner container with fluid, and sealing the inner and outer containers to prevent leakage of the fluid contained in the inner bag;

d) conveying a boxed back container filled in a second position away from the first position;

e) opening the exterior and interior containers to empty the flow material of the interior containers for use in the second position;

f) removing the empty inner container from the outer container;

g) after folding the inner container together, the folded inner container is transported from the second position to the first position or the third position;

h) repeating steps b) to g);

Steps b) to g) are repeated about 90,000 times without replacing, for example, the flexible built-in container.

In the specification, 'film' means a film and a sheet.

Next will be described in detail the inner bag made of polyethylene resin for box type according to the present invention.

Polyethylene resin

The inner bag of the polyethylene resin for box type bag according to the present invention is formed of a polyethylene resin of a specific ethylene copolymer [A].

Ethylene Copolymer [A]

The ethylene copolymer [A] used in the present invention is a random copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms.

The ethylene copolymer [A] has a density (d) of 0.880 to 0.960 g / cm ³ , preferably 0.880 to 0.950 g / cm ³ , more preferably 0.885 to 0.940 g / cm ³ , and particularly preferably 0.890 to 0.935 g / cm ³ .

The density (d) is obtained by the following method. The strand obtained at the time of melt flow rate (MFR) measurement of 190 degreeC and a load of 2.16 kg is heat-processed at 120 degreeC for 1 hour, and then gradually cooled to room temperature over 1 hour, and density is measured using a gradient density tube.

The ethylene copolymer [A] contains 65 to 99% by weight, preferably 70 to 98% by weight, more preferably 75 to 96% by weight of structural units derived from ethylene, and is derived from 3 to 20 carbon atoms. It is desired to contain 1 to 35% by weight of the structural unit, preferably 2 to 30% by weight, more preferably 4 to 25% by weight.

The composition of the ethylene copolymer (ethylene / α-olefin copolymer) is a sample obtained by uniformly dissolving about 200 mg of the copolymer in 1 ml of hexachlorobutadiene in a test tube having a diameter of 10 mm. It is obtained by measuring ¹³ C-NMR under measurement conditions of Hz, pulse repetition time 4.2 seconds, and pulse width of ^{6 s} .

Examples of α-olefins having 3 to 20 carbon atoms which can be used in the present invention include propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene and 1-dode Sen, 1- tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, etc. are mentioned.

The melt flow rate (MFR) of the ethylene copolymer [A] is 0.01 to 20 g / 10 minutes, preferably 0.03 to 15 g / 10 minutes, more preferably 0.05 to 10 g / 10 minutes.

Melt flow rate (MER) is measured by ASTM D 1238-65T under conditions of a temperature of 190 ° C. and a load of 2.16.

The intrinsic viscosity ([η]) of the ethylene copolymer [A] is 0.8 to 4.5 dl / g, preferably 0.9 to 4.0 dl / g, more preferably 1.0 to 3.5 dl / g, measured in decalin at 135 ° C. to be.

When the relationship between the intrinsic viscosity ([η]) and the melt flow rate (MFR) is expressed by the formula [η] = K × MFR ^c (K and C are integers, respectively), the C value of the ethylene copolymer [A] is- It is 0.140-0.180, and C value of this ethylene copolymer [A] is larger than C value of the ethylene copolymer of the same molecular weight distribution manufactured using the conventional titanium catalyst. Representative K value of the ethylene copolymer [A] used in the present invention is 1.6, and C value is -0.156. On the other hand, the representative K value of the ethylene copolymer of the same molecular weight distribution prepared using a conventional titanium catalyst is 1.84 and C value is -0.194.

The specific phosphorus molecular weight distribution (Mw / Mn) of the weight average molecular weight (Mw) and quantity average molecular weight (Mn) of an ethylene copolymer [A] is 2.0-6.0 normally.

The number of unsaturated bonds in the ethylenic copolymer [A] is 0.5 or less per 1,000 carbon atoms and 1 or less per molecule of the copolymer.

Since the number of unsaturated bonds present in the ethylene copolymer [A] is small, since the crosslinking reaction hardly occurs when the copolymer is heated in a molten state, the copolymer shows excellent thermal stability.

The amount of unsaturated bonds is obtained by the following method. In other words, the area strengths of signals belonging to the double bond (ie, signals within the range of 10 to 50 ppm) and signals belonging to the double bond (ie, signals within the range of 105 to 150 ppm) are obtained from the integral curve by ¹³ C-NMR. . The number of unsaturated bonds is obtained by the ratio between these intensities.

In the ethylene copolymer [A], the temperature (melting point, Tm) (° C.) and the density (d) (g / cm ³ ) at the maximum peak position of the endothermic curve measured by a differential scanning calorimeter (DSC) are expressed as follows. Satisfies:

Tm <400 x d-250,

Preferably it is Tm <450 * d-297,

More preferably, Tm <500 × d-344,

Especially preferably, Tm <550xd-391.

Temperature (melting point, Tm) of the maximum peak position of the endothermic curve measured by a differential scanning calorimeter (DSC) is about 5 mg of the sample heated to 200 ° C. at a rate of 10 ° C./min in an aluminum pan. The sample is left at 200 ° C. for 5 minutes, cooled to room temperature at a rate of 20 ° C./min, and then obtained from an endothermic curve obtained by heating at a rate of 10 ° C./min. The endothermic curve is measured using a DSC-7 model device manufactured by Perkin Elmer.

Since the above-mentioned ethylene copolymer has a low Tm with respect to the density, the sealing property is better than that of the ethylene copolymer of the same density produced using a conventional titanium catalyst.

The ethylene copolymer [A] has n-decane soluble fraction (W (% by weight)) and density (d) (g / cm ³ ) at room temperature satisfying the following relationship.

For MFR≤10g / 10min:

W <80 x exp (-100 (d-0.88)) + 0.1,

Preferably, W <60 x exp (-100 (d-0.88)) + 0.1,

More preferably, W <40xexp (-100 (d-0.88)) + 0.1,

For MFR> 10g / 10 minutes:

W <80 x (MFR-9) ^0.35 x exp (-100 (d-0.88)) + 0.1.

The composition distribution of such an ethylene copolymer can be said to be narrow.

The n-decane soluble content is measured by the following method. About 3 g of copolymer is added to 450 ml of n-decane, dissolved at 145 ° C and cooled to room temperature. The n-decane insoluble portion is then removed by filtration and the n-decane soluble portion is recovered from the filtrate. The smaller the amount of n-decane solubles, the narrower the composition distribution.

Ethylene-based copolymers [A] have a flow index (FI (l / sec)) and a melt flowrate defined by the shear rate given when the molten polymer has a stress at 190 ° C. of 2.4 × 10 ⁶ dyne / cm ² . MFR (10 minutes) satisfies the following equation:

FI> 75 × MFR

Preferably FI> 80 × MFR

More preferably, FI> 85 x MFR

The flow index (FI) is determined by measuring the shear rate corresponding to the specified stress by extruding the resin at various shear rates through the capillary. In other words, using the same sample as the MT measurement, by using a capillary flow island tester manufactured by Toyo Seiki Seisakusho Co., Ltd., a resin temperature of 190 ° C. and a shear stress of about 5 × 10 ⁻⁴ to 3 × 10 ^-6 dyne / cm ² Measure under the conditions of In this measurement, the diameter of the nozzle was changed as follows according to MFR (g / 10min) of resin.

MFR> 20: 0.5mm

20≥MFR> 3: 1.0mm

3≥MFR> 0.8: 2.0mm

0.8≥MFR: 3.0mm

When the ethylenic copolymer having a narrow composition distribution is produced using the conventional technique, the molecular weight distribution of the copolymer decreases, fluidity decreases, and FI decreases. Since the ethylene copolymer used in the present invention has the above relationship between FI and MFR, the shear stress can be kept low even in the high shear region, so that the moldability is improved.

In addition, in the ethylene copolymer [A], the melt tension (MT (g)) and the melt flow rate (MFR (g / 10 min)) at 190 ° C satisfy the following relationship.

MT> 2.0 × MFR ^-0.65

Preferably MT> 2.2 × MFR ^-0.65 ,

More preferably, MT> 2.5 × MFR ^-0.65

The melt tension (MT (g)) is determined by measuring the stress applied when the molten polymer is drawn at a constant speed. That is, the polymer powder produced by the conventional method is melted and then pelletized to make a sample. The MT of the sample was measured under conditions of a resin temperature of 190 ° C., a resin extrusion speed of 15 mm / min, a winding speed of 10 to 20 m / min, a nozzle diameter of 2.09 mm, and a nozzle length of 8 mm using an MT measuring instrument (manufactured by Toyo Seiki Seisakusho K.K). In the pelletization treatment, 0.05% by weight of tri (2,4-di-butylphenyl) phosphate as the secondary antioxidant and n-octadecyl-3- (4'-hydroxy-3 ', 5'- as the thermal stabilizer 0.1 weight% of di-t-butylphenyl) propionate and 0.05 weight% of calcium stearate are added as a hydrochloric acid absorbent.

The ethylene copolymer [A] used in the present invention has higher melt tension (MT) and better moldability than the conventional ethylene copolymer.

In the ¹³ C-NMR spectrum of the ethylenic copolymer [A], no signals of α β and βγ based on the methylene sequence between the tertiary carbon atoms of the adjacent copolymer main chains were observed. The physical meaning is described in detail in Japanese Patent Application Laid-Open No. 62-121709, and the result shows that the bonding direction of the α-olefin copolymerized with ethylene in the ethylene copolymer [A] is measured.

The ethylene copolymer [A] used in the present invention is

(a) a group IVB transition metal compound having a bidentate ligand in which two groups selected from specific indenyl groups and derivatives thereof are bonded through lower alkylene groups, or IVBs containing specific substituted cyclopentadienyl groups as ligands; Family transition metal compound,

(b) organoaluminum oxy compounds,

(c) carrier

As required

(d) organoaluminum compounds

In the presence of a metallocene catalyst for olefin polymerization, the copolymer may be prepared so as to have a density of 0.880 to 0.950 g / cm ³ of the copolymer for producing ethylene and an α-olefin having 3 to 20 carbon atoms.

The manufacturing method is described in detail in Japanese Patent Laid-Open No. 6-9724.

Ethylene-based copolymer [A] includes various additives such as weather stabilizer, heat stabilizer, antistatic agent, antislip agent, antiblocking agent, antifogging agent, lubricant, pigment, dye, nucleating agent, plasticizer, anti-aging agent, hydrochloric acid absorbing agent and antioxidant. It can add as needed within the range which does not deviate from the objective of this invention. In addition, other high molecular weight compounds can also be blended in small amounts without departing from the object of the present invention.

Ethylene Copolymer Composition [I]

In the present invention, the ethylene copolymer [C] other than the ethylene copolymer [B] and the ethylene copolymer [B], which is a kind of the ethylene copolymer [A], in addition to the polyethylene resin containing only the ethylene copolymer (A) Ethylene-based copolymer composition [I] can be used as the polyethylene resin.

The ethylene copolymer [B] constituting the ethylene copolymer composition [I] is a random copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms.

The ethylene copolymer [B] contains 55 to 99% by weight, preferably 65 to 98% by weight, more preferably 70 to 96% by weight of a structural unit derived from ethylene, and a structural unit derived from α-olefin. It is desired to contain 1 to 45% by weight, preferably 2 to 35% by weight, more preferably 4 to 30% by weight.

The ethylene copolymer [B] has the following physical properties (B-i) to (B-vi).

(Bi) The density d is in the range of 0.875 to 0.940 g / cm ³ , preferably 0.890 to 0.935 g / cm ³ , more preferably 0.900 to 0.930 g / cm ³ .

(B-ii) Intrinsic viscosity [eta _B ] is 1.0-10.0 dl / g, Preferably it is 1.25-8 dl / g, More preferably, it is the range of 1.27-6 dl / g measured in decalin at 135 degreeC. The melt flow rate (MFR) of the ethylene copolymer [B] is in the range of 0.01 to 10 g / 10 minutes.

(B-iii) Melt tension (MT (g)) and melt flow rate (MFR (g / 10 min)) at 190 ° C satisfy the following relationship:

MT> 2.2 × MFR ^-0.84

The ethylene copolymer [B] has high melt tension and good moldability.

(B-iv) The flow index (FI (l / sec)) and melt flow rate (MFR (10 min)), defined as the shear rate given when the stress at 190 ° C reaches 2.4 × 10 ⁶ dyne / cm ² , It is desired to satisfy the following equation:

FI> 75 × MFR

Preferably FI> 100 × MFR

More preferably FI> 120 x MFR.

(Bv) The temperature (melting point, Tm (° C.)) and density (d (g / cm ³ )) of the maximum peak position of the endothermic curve measured by differential scanning calorimeter (DSC) should satisfy the following relation:

Tm <400 × d-250,

Preferably it is Tm <450 * d-297,

More preferably, Tm <500 × d-344,

Especially preferably, Tm <550xd-391.

(B-vi) n-decane soluble fraction (W (% by weight)) and density (d) (g / cm ³ ) at room temperature satisfy the following relationship.

W <80 x exp (-100 (d-0.88)) + 0.1,

Preferably, W <60 x exp (-100 (d-0.88)) + 0.1,

More preferably, W <40 x exp (-100 (d-0.88)) + 0.1.

The relationship between the temperature (melting point, Tm) and density (d) and the n-decane soluble fraction (W) and density (d) at the maximum peak position of the endothermic curve measured by differential scanning calorimeter (DSC) It can be said that the ethylene copolymer [B] having has a narrow compositional distribution.

Ethylene-based copolymer [B] having the above-mentioned physical properties includes a group IV transition metal compound containing ethylene and an α-olefin having 3 to 20 carbon atoms (a) a ligand having a cyclopentadienyl skeleton, and (b) It is prepared by copolymerizing the density of the copolymer produced in the presence of an organoaluminum oxy compound, (c) a carrier and, if necessary, a catalyst for olefin polymerization formed of (d) an organoaluminum compound, to be 0.875 to 0.940 g / cm ^3. Can be. The manufacturing method of an ethylene copolymer [B] is described in detail in Unexamined-Japanese-Patent No. 6-136195.

The ethylene copolymer [C] constituting the ethylene polymer composition [I] together with the ethylene copolymer [B] is a random copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms. This ethylene copolymer [C] may be the same as or different from the ethylene copolymer [A].

The ethylene copolymer [C] contains 55 to 99% by weight of structural units derived from ethylene, preferably 65 to 98% by weight, more preferably 70 to 96% by weight of structural units derived from α-olefins. It is desired to contain 1 to 45% by weight, preferably 2 to 35% by weight, more preferably 4 to 30% by weight.

The ethylene copolymer [C] has the following physical properties (C-i) to (C-iv).

(Ci) The density d is in the range of 0.910 to 0.965 g / cm ³ , preferably 0.915 to 0.955 g / cm ³ , and more preferably 0.920 to 0.950 g / cm ³ .

(C-ii) Intrinsic viscosity [η _C ] is 0.5-2.0 dl / g, Preferably it is 0.05-1.9 dl / g, More preferably, it is the range of 0.6-1.8 dl / g measured in decalin at 135 degreeC.

(C-iii) The temperature (melting point, Tm) (℃) and the density (d) (g / cm ³ ) at the maximum peak position of the endothermic curve measured by a differential scanning calorimeter (DSC) should satisfy the following relationship. do:

Tm <400 × d-250,

Preferably it is Tm <450 * d-297,

More preferably, Tm <500 × d-344,

Especially preferably, Tm <550xd-391.

(C-iv) The n-decane soluble fraction (W (% by weight)) and density (d) (g / cm ³ ) at room temperature satisfy the following equation.

For MFR≤10 g / min:

W <80 x exp (-100 (d-0.88)) + 0.1,

Preferably, W <60 x exp (-100 (d-0.88)) + 0.1,

More preferably, W <40xexp (-100 (d-0.88)) + 0.1,

For MFR> 10 g / min:

W <80 x (MFR-9) ^0.26 x exp (-100 (d-0.88)) + 0.1.

The relationship between the temperature (melting point, Tm) and density (d) and the n-decane soluble fraction (W) and density (d) at the maximum peak position of the endothermic curve measured by differential scanning calorimeter (DSC) It can be said that the ethylene copolymer [C] having has a narrow compositional distribution.

Ethylene-based copolymer [C] having the above-mentioned physical properties includes a Group IV transition metal compound containing ethylene and a ligand having a (a ') cyclopentadienyl skeleton containing 3 to 20 carbon atoms, and (b ) Copolymerized so as to have a density of 0.910 to 0.960 g / cm ^{3 in} the presence of an organoaluminum oxy compound, (c) a carrier and, if necessary, a catalyst for olefin polymerization formed of (d) an organoaluminum compound. You can do it. The manufacturing method of an ethylene copolymer [C] is described in detail in Unexamined-Japanese-Patent No. 6-136195.

The ethylene polymer composition composed of the ethylene copolymer [B] and the ethylene copolymer [C] contains 5 to 95% by weight of the ethylene copolymer [B], preferably 10 to 90% by weight, and the ethylene copolymer It is desired to contain 5 to 95% by weight of [C], preferably 10 to 90% by weight.

The ethylene copolymers [B] and [C] have a density ratio ([B] / [C]) of ethylene copolymer [B] and ethylene copolymer [C] of 1 or less, preferably 0.930 to 0.999. Use if possible. In addition, the ethylene copolymer [B] and [C] are the ratio ([η _B ] / of the intrinsic viscosity [η _B ] of the ethylene copolymer [ _B ] and the intrinsic viscosity [η _C ] of the ethylene copolymer [C]. [η _C ]) is 1 or more, preferably 1.05 to 10, more preferably 1.1 to 5 is used.

The density of the ethylene copolymer composition [I] of the ethylene copolymer [B] and the ethylene copolymer [C] is 0.880 to 0.960 g / cm ³ , preferably 0.900 to 0.950 g / cm ³ , and the melt flow The rate (MFR) is 1 to 20 g / 10 minutes, preferably 0.2 to 15 g / 10 minutes.

The ethylene copolymer composition [I] includes various additives such as weather stabilizer, heat stabilizer, antistatic agent, antislip agent, antiblocking agent, antifogging agent, lubricant, pigment, dye, nucleating agent, plasticizer, antioxidant, hydrochloric acid absorbent, antioxidant It can add as needed within the range which does not deviate from the objective of this invention.

Ethylene copolymer composition [I] can be manufactured, for example by the following conventional method.

(1) The ethylene copolymer [B], the ethylene copolymer [C] and any additives are mechanically melt blended using an extruder, a kneader, or the like.

(2) Ethylene copolymer [B], Ethylene copolymer [C] and any additives are added in an appropriate amount of solvent (for example, hydrocarbon solvents such as hexane, heptane, decane, cyclohexane, benzene, toluene, xylene) After dissolving in, the solvent is removed.

(3) Ethylene copolymer [B], Ethylene copolymer [C] and optional additives are dissolved in appropriate amounts of solvent, respectively, to prepare a solution, then these solutions are mixed and the solvent is removed from the mixture. .

(4) The above processes (1) to (3) are executed in any combination.

The ethylene copolymer composition [I] can be produced by dividing the ethylene copolymer [B] and the ethylene copolymer [C] in two or more steps under different reaction conditions. Alternatively, the ethylene copolymer composition [I] can be produced by producing an ethylene copolymer [B] and an ethylene copolymer [C] with a plurality of polymerization reactors.

The ethylene copolymer composition [I] prepared as above has excellent thermal stability and moldability.

Ethylene Copolymer Composition [II]

In the present invention, the ethylene copolymer composition [II] made of an ethylene copolymer [A] and a high pressure low density polyethylene [D] can be used as polyethylene resins other than the above-described polyethylene resins.

The ethylene copolymer [A] constituting the ethylene copolymer composition [II] is as described above, but the ethylene copolymer [A] used in the composition is the same as the copolymer used alone as a polyethylene resin. It differs in terms of preferred density, melt fluorate (MFR) and the like. The ethylene copolymer [A] used in the ethylene copolymer composition [II] will be described.

The ethylene copolymer [A] is a random copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms.

The ethylene copolymer [A] contains 55 to 99% by weight, preferably 65 to 98% by weight, more preferably 70 to 96% by weight of a structural unit derived from ethylene, and has α- having 3 to 20 carbon atoms. It is desired that the structural unit derived from the olefin contain 1 to 45% by weight, preferably 2 to 35% by weight, more preferably 4 to 30% by weight.

The density (d) of the ethylene copolymer [A] is 0.880 to 0.965 g / cm ³ , preferably 0.890 to 0.935 g / cm ³ , more preferably 0.905 to 0.930 g / cm ³ .

The melt flow rate (MFR) of the ethylene copolymer [A] is 0.01 to 20 g / 10 minutes, preferably 0.05 to 15 g / 10 minutes, more preferably 0.1 to 10 g / 10 minutes.

Ethylene-based copolymer [A] satisfies the following relationship with temperature (melting point, Tm (℃)) and density (d (g / cm ³ )) at the maximum peak position of the endothermic curve measured by differential scanning calorimeter (DSC). do:

Tm <400 × d-250,

Preferably it is Tm <450 * d-297,

More preferably, Tm <500 × d-344,

Especially preferably, Tm <550xd-391.

In the ethylene copolymer [A], the melt tension (MT (g)) and the melt flow rate (MFR (g / 10 min)) at 190 ° C satisfy the following relationship.

MT≤2.2 × MFR ^-0.64

In the ethylene copolymer [A], the n-decane soluble fraction (W (% by weight)) and density (d (g / cm ³ )) at 23 ° C satisfy the following relationship.

For MFR≤10 g / min:

W <80 x exp (-100 (d-0.88)) + 0.1,

Preferably, W <60 x exp (-100 (d-0.88)) + 0.1,

More preferably, W <40xexp (-100 (d-0.88)) + 0.1,

For MFR> 10 g / min:

W <80 x (MFR-9) ^0.26 x exp (-100 (d-0.88)) + 0.1.

The number of unsaturated bonds in the molecule of the ethylenic copolymer [A] is 0.5 or less per 1,000 carbon atoms and 1 or less per molecule of the copolymer.

The ethylenic copolymer [A] has a B value of 1.00 ≦ B, preferably 1.01 ≦ B ≦ 1.50, more preferably 1.01 ≦ B ≦ 1.30, wherein the B value is represented by the following formula:

B = PoE / (2PoPE)

Where PE is the mole fraction of the ethylene component contained in the copolymer, Po is the mole fraction of the α-olefin contained in the copolymer, and PoE is the mole fraction of α-olefin / ethylene sequence in all the diad sequence.

B value is an index of each monomer distribution of a copolymer chain, and this B value is G.J. Ray (Macromolecules, 10, 773 (1977)), J.C. Randall (Macromolecules, 15, 353 (1982)), J. Polymer Science, Polymer Physics Ed. 11, 275 (1973)), K. Kimura (Polymer, 25, 441 (1984)), using PE, Po and PoE. The larger the B value, the smaller the number of block-shaped sequence, which means that the distribution of ethylene and α-olefin is uniform and the composition distribution of the copolymer is narrow.

The B value is obtained by the following method. ¹³ C-NMR spectra of a sample obtained by uniformly dissolving about 200 mg of a copolymer in 1 ml of hexachlorobutadiene in a 10 mm diameter tube were measured at 120 ° C., measurement frequency 25.05 MHz, spectrum width 1,500 Hz, and pulse repetition time 4.2 seconds. Measured under the measurement conditions of pulse width of 7 μsec and integration frequency of 2,000 to 5,000. Next, PE, Po and PoE are calculated from this spectrum to calculate the B value.

Ethylene-based copolymers [A] having the above properties include ethylene and an α-olefin having 3 to 20 carbon atoms (a) a Group IV transition metal compound containing a ligand having a cyclopentadienyl skeleton, and (b) It is prepared by copolymerizing the density of the copolymer produced in the presence of an organoaluminum oxy compound, (c) a carrier and, if necessary, a catalyst for olefin polymerization formed of (d) an organoaluminum compound, so as to have a density of 0.880 to 0.960 g / cm ^3. There is a number. The manufacturing method of an ethylene copolymer [A] is described in detail in Unexamined-Japanese-Patent No. 6-9724 and 6-65443.

Next, the high pressure low density polyethylene [D] which comprises an ethylene polymer composition [II] with an ethylene copolymer [A] is demonstrated in detail.

High pressure low density polyethylene [D] is a polyethylene having a large number of branches including long chain branches, and is prepared by 'high pressure radical polymerization'. Melt flow rate (MFR) of this polyethylene [D] is 0.1-50 g / 10 minutes, Preferably it is 0.2-10 g / 10 minutes, More preferably, 0.2-8 g / 10 minutes measured on 190 degreeC and the conditions of 2.16 load. to be.

For high pressure low density polyethylene [D], the molecular weight distribution (Mw / Mn, Mw: weight average molecular weight, Mn: number average molecular weight) and melt flow rate (MFR) measured by gel permeation chromatography (GPC) satisfy the following relationship:

7.5 × log (MFR) -1.2≤Mw / Mn≤7.5 × log (MFR) +12.5,

Preferably

7.5 × log (MFR) -0.5≤Mw / Mn≤7.5 × log (MFR) +12.0,

More preferably

7.5 x log (MFR) <Mw / Mn <7.5 x log (MFR) + 12.0.

The molecular weight distribution (Mw / Mn) of high pressure low density polyethylene [D] was measured by the following method using GPC-150C manufactured by Millipore Co.

A TSK-GNH-HT separation column of 72 mm in diameter and 600 mm in length was used. The column temperature was previously set at 140 ° C. A sample (concentration: 0.1 wt%, amount: 500 μm) was used as o-dichlorobenzene (manufactured by Wako Pure Chemical Industries, Ltd.) as a mobile phase, and 0.025 wt% BHT (manufactured by Takeda Chemical Industries, Ltd.) as an antioxidant. The column was moved at a rate of 1.0 ml / min. A differential refractometer was used as a detector. As standard polystyrene, the thing of Mw <1,000 and Mw> 4x10 < ⁶ > made from TOSOH KK and the thing of 1,000 <Mw <4x10 <^{6> made} from Pressure Chemical Co. were used.

The density d of the high pressure low density polyethylene [D] needs to be 0.910-0.930g / cm <^3> .

Density is calculated by the following method. In other words, the strand obtained at the time of measuring the melt florate (MFR) at 190 ° C under a load of 2.16 kg was subjected to heat treatment at 120 ° C for 1 hour, and then gradually cooled to room temperature over 1 hour to measure density using a gradient density tube.

High pressure, low density polyethylene [D] is used to determine the degree of long chain branching.

The expansion ratio, i.e., the ratio of the diameter (Ds) and the nozzle diameter (D) of the strand extruded from a nozzle having an internal diameter (D) of 2.0 mm and a length of 15 mm at a extrusion speed of 10 mm / min at 190 ° C using a capacitive flow tester is 1.3 ( It is desired that it is more than Ds / D).

The high pressure low density polyethylene [D] used for this invention may be a copolymer of ethylene and the polymerizable monomers, such as another alpha olefin, vinyl acetonitrile, an acrylic ester, unless the objective of this invention is impaired.

The ethylene copolymer composition [II] of the ethylene copolymer [A] and the high pressure low density polyethylene [D] has a weight ratio ([A]: [B]) between the ethylene copolymer [A] and the high pressure low density polyethylene [D]. The value is 99: 1 to 65:35, preferably 90:10 to 65:35, and more preferably 80:20 to 65:35. In other words, the polyethylene resin of this composition [II] is 90-65 weight%, Preferably it is 90-65 weight%, More preferably, it is 80-65 weight% Ethylene-type copolymer [A] and 1-35 weight %, Preferably 10 to 35% by weight, more preferably 20 to 35% by weight of high pressure low density polyethylene [D].

When the ratio of high pressure low density polyethylene [D] is less than the above-mentioned, improvement of melt tension will become inadequate. If the ratio is larger than the above, pinhole resistance and flex resistance are significantly reduced.

The density of the ethylene copolymer composition [II] of the ethylene copolymer [A] and the high pressure low density polyethylene [D] is 0.880 to 0.950 g / cm ³ , preferably 0.885 to 0.950 g / cm ³ , and the melt flow rate (MFR) is 0.01-20 g / 10 minutes, Preferably it is 0.03-15 g / 10 minutes.

The ethylene copolymer composition [II] includes various additives such as weather stabilizer, heat stabilizer, antistatic agent, antislip agent, antiblocking agent, antifogging agent, lubricant, pigment, dye, nucleating agent, plasticizer, anti-aging agent, hydrochloric acid absorber, antioxidant, etc. It can add as needed within the range which does not deviate from the objective of this invention.

Ethylene copolymer composition [II] can be manufactured, for example by the following conventional method.

(1) The ethylene copolymer [A], the high pressure low density polyethylene [D] and optional additives are mechanically melt blended using an extruder, a kneader or the like.

(2) Ethylene copolymer [A], high pressure low density polyethylene [D] and optional additives are added in a suitable amount of solvent (for example, hydrocarbon solvents such as hexane, heptane, decane, cyclohexane, benzene, toluene, xylene). After dissolving, the solvent is removed.

(3) An ethylenic copolymer [A], a high pressure low density polyethylene [D], and optional additives are each dissolved in a suitable amount of solvent to prepare a solution, and then the solution is mixed and the solvent is removed from the mixture.

(4) The above processes (1) to (3) are executed in any combination.

The ethylene copolymer composition [II] prepared as described above exhibits excellent moldability because of its high melt tension and low stress in the high shear region.

Ethylene Copolymer Composition [III]

In the present invention, the ethylene copolymer composition [I] made of the ethylene copolymer composition [I] and the high pressure low density polyethylene [D] can be used as a polyethylene resin other than the above-described polyethylene resin.

The ethylene copolymer composition [III] has a weight ratio ([I]: [B]) of 99: 1 to 65:35, preferably 99: 5, between the ethylene copolymer composition [I] and the high pressure low density polyethylene [D]. -65:35, More preferably, it is the range of 90: 10-65: 35.

When the ratio of high pressure low density polyethylene [D] is less than the above-mentioned, improvement of melt tension will become inadequate. If the ratio is larger than the above, pinhole resistance and flex resistance are significantly reduced.

Ethylene copolymer composition [III] can be manufactured, for example by the following conventional method.

(1) The ethylenic copolymer composition [I], high pressure low density polyethylene [D], and optional additives are mechanically melt blended using an extruder, a kneader, or the like.

(2) Ethylene-based copolymer composition [I], high pressure low density polyethylene [D] and optional additives may be added in an appropriate amount of solvent (for example, hydrocarbon solvents such as hexane, heptane, decane, cyclohexane, benzene, toluene and xylene). After dissolving in, the solvent is removed.

(3) Ethylene copolymer composition [I], high pressure low density polyethylene [D], and optional additives are dissolved in appropriate amounts of solvent, respectively, to prepare a solution, and then the solution is mixed and the solvent is removed from the mixture. .

(4) The above processes (1) to (3) are executed in any combination.

The ethylene copolymer composition [III] includes various additives such as weather stabilizer, heat stabilizer, antistatic agent, antislip agent, antiblocking agent, antifogging agent, lubricant, pigment, dye, nucleating agent, plasticizer, antioxidant, hydrochloric acid absorbent, antioxidant, etc. It can add as needed within the range which does not deviate from the objective of this invention.

The ethylenic copolymer composition [III] obtained as described above has excellent thermal stability and moldability.

Polyethylene resins made of ethylene copolymer [A], ethylene copolymer composition [I], ethylene copolymer composition [II], or ethylene copolymer composition [III] are selected between the melt tension and fluidity by extrusion or blow molding. A good balance is obtained, and workability is improved as compared with a conventional medium or low pressure ethylene copolymer.

Polyethylene resin inner container for box type bag

The polyethylene inner container for a box type bag according to the present invention is formed of the above-mentioned polyethylene resin film.

The thickness of the film forming the polyethylene inner container for the box type bag varies depending on the contents of the container or the manufacturing method of the container, but is usually in the range of 30 to 1,000 µm, preferably 50 to 700 µm.

The film forming the polyethylene inner container for a boxed bag has the following physical properties:

(i) the blocking force is 1.0 g / cm;

(ii) the number of pinholes formed on an area of 20.5 cm x 28.0 cm after repeated twisting 2,000 times in a film using a gelbo bending tester was 2 or less;

(iii) The number of bends measured in accordance with JIS P-8115 is 90,000 or more.

In addition, the neck-in during the molding process is preferably 20 cm or less on one side.

The polyethylene inner container for box type bag according to the present invention is a single layer film made of polyethylene resin or a polyethylene resin layer and another resin layer (for example, nylon, ethylene / vinyl alcohol copolymer resin (EVOH), polyvinyl alcohol, adhesive resin). Can be formed into a multilayer film.

Manufacturing method of polyethylene inner container for box type bag

The polyethylene inner container for a box type bag according to the present invention can be produced, for example, by the following method.

(i) Vacuum molding using a mold having a shape in which the outer periphery can be joined along the symmetry line after two sheets of molten polyethylene resin are extruded from the T-die in parallel to each other in the longitudinal direction. do.

(ii) The molten resin is extruded from the annular die into a cylindrical shape (Perison extrusion method) and then blow molded as above using the same mold.

(iii) Two or more polyethylene films superimposed on each other are heat sealed in four directions to form a bag. Each film in this treatment is made of a single layer film made of polyethylene resin or a resin layer different from the polyethylene resin layer (for example, nylon, ethylene / vinyl alcohol copolymer resin (EVOH), polyvinyl alcohol, adhesive resin). It can be formed into a multilayer film.

Example

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

The physical properties used here, the measurement method of the physical properties and the molding method are defined below.

(1) granulation of a copolymer or copolymer composition

0.05 part by weight of tri (2,4-di-t-butylphenyl) phosphate as a secondary antioxidant per 100 parts by weight of the powder copolymer or copolymer composition, and n-octadecyl-3- (4'-hydroxy as a heat stabilizer. 0.1 parts by weight of -3 ', 5'-di-t-butylphenyl) propionate and 0.05 parts by weight of calcium stearate were mixed as a hydrochloric acid absorbent. Thereafter, the mixture was melt-extruded with a biaxial conical tapered extruder manufactured by Hark Co., Ltd. at a set temperature of 180 ° C. to produce granular ferrets.

(2) density

The strand obtained upon measurement of melt flow rate (MFR) at 190 ° C. under 2.16 kg of load was heat treated at 120 ° C. for 1 hour, and gradually cooled to room temperature over 1 hour. Thereafter, the density of the copolymer or the copolymer composition was measured by a density gradient tube.

(3) copolymer composition

The composition of the copolymer was determined by ¹³ C-NMR. That is, ¹³ C-NMR spectra of a sample obtained by uniformly dissolving about 200 g of a copolymer in 1 ml of hexachlorobutadiene in a 10 mm diameter sample tube were measured at 120 ° C., measurement frequency 25.05 NHz, spectral width 1500 Hz, and pulse repetition time 4.2. It measured and determined under the measurement conditions of 6 microsecond of a second and pulse width.

(4) Melt Flow Rate (MFR)

Using the granular ferret of the copolymer or copolymer composition, the melt flow rate (MFR) was measured according to ASTM D 1238-65T under conditions of a temperature of 190 ° C. and a load of 2.16 kg.

(5) Intrinsic Viscosity ([η])

Intrinsic viscosity ([η]) was measured at 135 ° C. using a decalin solvent. That is, about 20 mg of granular ferret was dissolved in 15 ml of decalin, and the specific viscosity (η _sp ) of the resulting solution was measured in an oil bath at 135 ° C. To this decalin solution, 5 ml of decalin solvent was further added and diluted, and the specific viscosity (ηsp) of the resulting solution was measured. This dilution operation was repeated twice and the value obtained when extrapolating the concentration (C) to zero was obtained as the intrinsic viscosity (η).

[η] = lim (η _sp / C) (C → O)

(6) Molecular weight distribution (Mw / Mn)

The molecular weight distribution (Mw / Mn) was measured by GPC Model ALC-GPC-150C manufactured by Waters. The said measurement is performed at 140 degreeC using PSK-GMH-HT (made by Tosoh Corporation) column, and using orthodichlorobenzene (ODCB) as a solvent.

(7) Determination of Unsaturation

Quantification of the unsaturated bond was performed by the following method. In other words, the area intensity of signals belonging to the double bond (ie, signals in the range of 10 to 50 ppm) and signals belonging to the double bond (ie, signals in the range of 105 to 150 ppm) is determined from the integrating curve by ¹³ C-NMR. The unsaturated bond water was calculated | required as the ratio between these intensities.

(8) Measurement of maximum peak temperature (Tm)

The endothermic curve was measured using a DSC-7 model device manufactured by Perkin Elmer. The temperature at the maximum peak position of the endothermic curve (Tm (° C.)) is about 5 mg of the sample heated at 200 ° C. in an aluminum pan at a rate of 10 ° C./min, and the sample is held at 200 ° C. for 5 minutes, and then 20 ° C. / It obtained from the endothermic curve obtained by cooling to room temperature at the rate of minutes, and heating at the rate of 10 degree-C / min.

(9) n-decane soluble fraction (W)

The n-decane soluble fraction (W) was measured by the following method. About 3 g of copolymer was added to 450 ml of n-decane and dissolved at 145 ° C. and cooled to room temperature. The n-decane insoluble portion was removed by filtration, and the n-decane soluble portion was recovered from the filtrate.

The n-decane soluble fraction (W) is defined by the equation

W (%) = (W2 / W1) × 100

W1: The total weight of the n-decane insoluble portion and the n-decane soluble portion.

W2: weight of n-decane soluble part

The smaller the n-decane soluble component, the narrower the composition distribution.

(10) melt tension (MT)

The melt tension (MT (g)) is determined by measuring the stress when the molten polymer is stretched at a constant speed. In other words, using the granular pellet of the copolymer as a sample to be measured, and the conditions of the resin temperature 190 ℃, resin extrusion speed 15mm / min, winding speed 10 ~ 20m / min, nozzle diameter 2.09mm, nozzle length 8mm The measurement was performed using the MT measuring instrument by Sakusho Kabushiki Kaisha.

(11) Liquidity Index (FI)

The flow index (FI) is defined as the shear rate when the melt stress at 190 ° C. reaches 2.4 × 10 ⁶ dyne / cm ² . The flow index (FI) was determined by extruding the resin from the capillary while changing the shear rate and measuring the shear rate corresponding to the specified stress. That is, using the same sample as the MT measurement, the fluidity index (FI) was used as a capillary fluidity tester manufactured by Toyo Seiki Seisakusho Co., Ltd., and the resin temperature was 190 ° C and the shear stress was about 5 x 10 ^4. It measured on the conditions of -3 * 10 <^6> dyne / cm <^2> .

The nozzle diameter was changed as follows according to MFR (g / 10min) of resin in this measurement.

MFR> 20: 0.5mm

20≥MFR> 3: 1.0mm

3≥MFR> 0.8: 2.0mm

0.8≥MFR: 3.0mm

(12) Manufacturing method of interior container for BIB

A granular pellet of polyethylene resin, which is a copolymer or copolymer composition, was used as a sample. 8 kg per die were sampled from two T dies (width: 80 mm, lip opening: 1.2 mm) placed side by side with a distance of 50 mm and mounted on a single extruder (diameter: 65 mm, L / D = 28). The sheet was extruded into two sheets (each thickness: 1 mm) under an extrusion amount of 5 minutes, an extrusion rate of 5 mm / minute, and a resin temperature of 200 ° C. Thereafter, vacuum molding was performed using a mold having a shape of joining to the diagonal faces of the production container to form a 20-liter box-type inner container. The side thickness of the inner container thus formed is almost 500 μm. The uniform part of the side was cut | disconnected, the sample was cut | disconnected, and the following film property evaluation tests were done.

(13) Film property evaluation test

(a) Pinhole resistance

Pinhole resistance tests were performed according to US military standard MIL B 131. That is, after performing the film 2,000 times, the number of pinholes generated in the 20.5cm × 28.0cm region was measured by a gel voflex test, and the pinhole resistance was evaluated by the number of pinholes.

(b) flex resistance

In order to measure the number of bendings until the test sample was destroyed, a bending test was conducted according to JIS P-8115. Flexural resistance was evaluated by the number of bendings.

(c) blocking properties

A film sample of 7 cm (width) x 20 cm size was cut out, sandwiched between two sheets of paper, sandwiched between two sheets of glass, and a load of 10 kg was applied at 50 ° C for 24 hours in an air bath. The film was then separated at a rate of 200 mm / minute with a gripper. The load applied in the separating operation is A (g), and the blanking force F (g / cm) is expressed by the formula F = A / sample width. The smaller the value, the better the film has low blocking resistance, that is, the better blocking resistance.

Example using polyethylene resin composed of ethylene copolymer alone

Example 1

Preparation of Catalyst Components

In 121 liters of toluene, 7.9 kg of dried silica was suspended at 250 ° C. for 10 hours, and then cooled to 0 ° C. Then, 41 liters of toluene solution of methylaluminoxane (Al = 1.47 mol / liter) was added dropwise over 1 hour. The temperature of the system was kept at 0 ° C. during the addition. Subsequently, the said reaction was performed at 0 degreeC for 30 minutes, the temperature was raised to 95 degreeC over 1.5 hours, and reaction was performed at this temperature for 4 hours. The system was then cooled to 60 ° C. and poured off along the supernatant. The solid obtained above was washed twice with toluene and resuspended in 125 liters of toluene. To the system, 20 liters of toluene solution of bis (1,3-dimethylcyclopentadienyl) zirconium dichloride (Zr = 28.4 mmol / liter) was added dropwise at 30 DEG C over 30 minutes, followed by reaction at 30 DEG C for 2 hours. Done. The supernatant was then removed and the residue was washed twice with hexane to give a solid catalyst containing 4.6 mg of zirconium per 1 g of catalyst.

Preparation of Prepolymerization Catalyst

4.3 kg of the solid catalyst obtained above was added to 160 liters of the hexane solution containing 16 mol of triisobutyl aluminum, and ethylene prepolymerization was performed at 35 degreeC for 3.5 hours. Thereafter, 3 g of ethylene polymer per 1 g of solid catalyst was obtained by prepolymerization. The intrinsic viscosity [η] of the ethylene polymer was 1.27 dl / g.

polymerization

Copolymerization of ethylene and 1-hexene in a continuous fluidized-bed gas phase polymerization reactor was carried out under the condition of a total pressure of 20 kg / cm ² -G and a polymerization temperature of 80 ° C. In this copolymerization, the prepolymerization catalyst prepared above was continuously supplied to the system at a feed rate of 0.05 mmol / hour (zirconium atom conversion) and triisobutylaluminum at a feed rate of 10 mmol / hour. In order to maintain a constant gas composition during the polymerization, ethylene, 1-hexene, hydrogen, and nitrogen were continuously supplied to the system (gas composition: 1-hexene / ethylene = 0.018, hydrogen / ethylene = 0.0012, ethylene concentration = 25%). ). Polymer yield was 5.2 kg / hour.

As shown in Table 1, the polymer analysis results are as follows: density is 0.927 g / cm ³ , MFR is 1.0 g / 10 min, unsaturated bond number is 0.062 per 1,000 carbon atoms, 0.11 per molecule of copolymer, The maximum peak temperature of the measured endothermic curve was 117.8 ° C., and the n-decane soluble fraction was 0.22 wt% at room temperature.

The ethylene copolymer is formed into a box-type inner container for the molding method described above. Table 2 shows the evaluation results of the inner container.

Examples 2-6

Except for using various α-olefins shown in Table 1 as comonomers. Ethylene-based copolymers were prepared by copolymerizing ethylene and an -olefin in the same manner as in Example 1.

Table 1 shows the analysis results of the ethylene copolymer.

The ethylene copolymer was molded into the box-type inner bag for the above-mentioned molding method. Table 2 shows the evaluation results of the inner container.

Comparative Example 1

Ethylene / 4-methyl-1-pentene copolymer was prepared in a cyclohexane solvent using an MgCl ₂ supported Ti catalyst.

Table 1 shows the analysis results of the ethylene copolymer.

The said ethylene copolymer was shape | molded by the above-mentioned shaping | molding method with the box-type inner container. Table 2 shows the evaluation results of the inner container.

The copolymer of this comparative example had more n-decane-soluble moieties, higher Tm, and compared to the copolymer of Example 4 using the same comonomer (4-methyl-1-pentene) and having approximately the same MFR and density. , The balance between FI and MT was poor. From the evaluation results of the box-type bag-containing interior container, it can be seen that the interior container of the comparative example is inferior in both pinhole resistance, flex resistance, and blocking resistance.

Comparative Example 2

Ethylene / 1-hexene copolymer was prepared in the gas phase using MgCl ₂ supported Ti catalyst.

Table 1 shows the analysis results of the ethylene copolymer.

By the above molding method, the ethylene-based copolymer was molded into a box-type inner bag. Table 2 shows the evaluation results of the inner container.

In Table 1, the copolymer of this comparative example uses the same comonomer (1-hexene), has more n-decane-soluble moieties, higher Tm, compared to the copolymer of Example 2 having almost the same MFR and density, The balance between FI and MT was poor. In Table 2, it can be seen that the box-type inner bag for this comparative example is inferior in both pinhole resistance, flex resistance, and blocking resistance.

Comparative Example 3

80 parts by weight of an ethylene-based copolymer, premixed with 20 parts by weight of an ethylene / vinyl acetate copolymer (MFR (190 ° C.); 0.5 g / 10 min, vinyl acetate content; 10 wt%, density: 0.956 g / cm ³ ) Other than this was granulated in the same manner as in Comparative Example 1 to prepare a ferret.

The MFR, density, and n-decane soluble fraction of the polymers obtained above are shown in Table 1.

This polymer was manufactured into the box-type bag-containing interior container by the above-mentioned manufacturing method. Table 2 shows the evaluation results of the inner container.

Comparative Example 4

35 parts by weight of high-pressure low-density polyethylene (MFR (190 ° C): 0.6 g / 10 min, density: 0.920 g / cm ³ ) was used instead of ethylene / vinylacetate copolymer, and the amount of ethylene copolymer powder was changed to 65 parts by weight. One was to produce a ferret in the same manner as in Comparative Example 3.

The MFR and n-decane soluble fraction of the polymers obtained above are shown in Table 1.

This polymer was manufactured into the box-type bag-containing interior container by the above-mentioned manufacturing method. Table 2 shows the evaluation results of the inner container.

Comparative Example 5

The ethylene / vinyl acetate copolymer used in Comparative Example 3 was used to prepare a box-type bag-containing interior container by the molding method described above.

Table 2 shows the results of the evaluation of the interior container.

Polyethylene resin of ethylene copolymer composition [I]

Example used

Preparation Example 1

Preparation of Ethylene Copolymer [B]

polymerization

Copolymerization of ethylene and 1-hexene in a continuous fluidized bed polymerization reactor was carried out under conditions of a total pressure of 18 kg / cm ² -G and a polymerization temperature of 75 ° C. In this copolymerization, the prepolymerization catalyst used in Example 1 was continuously fed to the system at a feed rate of 0.05 mmol / hr (zirconium atom conversion) and triisobutylaluminum at a feed rate of 10 mmol / hr. In order to maintain a constant gas composition during the polymerization, ethylene, 1-hexene, hydrogen, and nitrogen were continuously supplied to the system (gas composition: 1-hexene / ethylene = 0.041, hydrogen / ethylene = 0.0011, ethylene concentration = 10%). ).

The yield of ethylene / 1-hexene polymer (a-1) was 6.0 kg / hour. The density is 0.906g / cm ³ , MFR is 0.32g / 10min, the maximum peak temperature (Tm) of the endothermic curve measured by DSC is 92.5 ℃, the melt tension is 190g at 190 ℃, and the fluidity index is 89 liters. N-decane soluble fraction at room temperature / 0.52% by weight, the number of unsaturated bonds was 0.09 per 1,000 carbon atoms, 0.90 per molecule of the copolymer.

Example 7

Ethylene produced in the same manner as in Preparation Example 1 except that the ethylene / 1-hexene copolymer (a-1) (density; 0.9 g / cm ³ ) and the comonomer content obtained in Preparation Example 1 were adjusted as shown in Table 3. The / 1-hexene copolymer (b-1) (density: 0.949 g / cm ³ ) was melt kneaded at a weight ratio of 57/43 (a-1 / b-1) to obtain an ethylene copolymer composition.

The said ethylene-based copolymer composition had a density of 0.926 g / cm ³ and an MFR of 1.1 g / 10 min.

The melt properties of the ethylene copolymer composition are shown in Table 4.

The composition was formed into a box-type inner bag by the molding method described above. Table 4 shows the evaluation results of the inner container.

Example 8

Except adjusting the comonomer content as shown in Table 3, the ethylene / 1-hexene copolymer (a-2) (density; 0.907 g / cm ³ ) prepared in the same manner as in Production Example 1, and ethylene-1 The hexene copolymer (b-2) (density: 0.943 g / cm ³ ) was melt kneaded at a weight ratio of 60/40 (a-2 / b-2) to obtain an ethylene copolymer composition.

The ethylene copolymer composition had a density of 0.921 g / cm ³ and an MFR of 2.0 g / 10 min.

The melt properties of the ethylene copolymer composition are shown in Table 4.

In the same manner as in Example 1, the ethylene-based copolymer composition was formed into a box-type inner bag.

Table 4 shows the evaluation results of the inner container.

Comparative Example 6

Instead of bis (1,3-dimethylcyclopentadienyl) zirconium dichloride, the titanium catalyst component described in JP-A-63-54289 is used, and triethylaluminum is used instead of methylaluminoxane, and comonomer Ethylene / 1-hexene copolymer (a-4) (density; 0.915 g / cm ³ ) prepared in the same manner as in Production Example 1, except that the content was adjusted as shown in Table 3, and ethylene / 1-hexene air The copolymer (b-4) (density: 0.933 g / cm ³ ) was melt kneaded at a weight ratio of 60/40 (a-4 / b-4) to obtain an ethylene copolymer composition.

The ethylene copolymer composition had a density of 0.922 g / cm ³ and an MFR of 2.0 g / 10 min.

The melt properties of the ethylene copolymer composition are shown in Table 4.

In the same manner as in Example 1, the ethylene-based copolymer composition was formed into a box-type inner bag.

Table 4 shows the results of the evaluation of the interior container.

The ethylene-based copolymer composition obtained in Comparative Example 6 in Tables 3 and 4 has a lower melt tension than the ethylene-based copolymer composition of Example 8 having almost the same density and MFR, and the box-type interior packaging container has moldability and pin resistance. It can be seen that it is poor in hole resistance, flex resistance and blocking resistance.

Comparative Example 7

An ethylene / 1-hexene copolymer (c-1) was prepared in the same manner as in Comparative Example 6 except that the comonomer content was adjusted as shown in Table 3.

The density of the ethylene / 1-hexene copolymer (c-1) was 0.922 g / cm ³ and the MFR was 1.9 g / 10 min, and the physical properties thereof were the same as those of the ethylene copolymer composition prepared in Comparative Example 6.

In the same manner as in Example 1, this ethylene / 1-hexene copolymer was molded into an interior container.

Table 4 shows the evaluation results of the inner container.

Compared with Examples 7 and 8, the ethylene / 1-hexene copolymer obtained in Comparative Example 7 in Tables 3 and 4 has a low degree of improvement in fluidity (FI) in the high shear region, and the resulting bag-containing interior container has moldability, It can be seen that pinhole resistance, bending resistance, and blocking resistance are poor.

Example 9

Ethylene / 1-hexene copolymer (a-3) (density; 0.916 g / cm ³ ) and bis (1,) prepared in the same manner as in Production Example 1, except that the comonomer content was adjusted as shown in Table 3. Bis (1-methyl-3-n-butylcyclopentadienyl) zirconium dichloride was used instead of 3-dimethylcyclopentadienyl) zirconium dichloride, except that the comonomer content was adjusted as shown in Table 3. , Melt-kneading the ethylene / 1-hexene copolymer (b-3) (density; 0.924 g / cm ³ ) prepared in the same manner as in Preparation Example 1 at a weight ratio of 20/80 (a-3 / b-3) And ethylene copolymer composition were obtained.

The ethylene copolymer composition had a density of 0.922 g / cm ³ and an MFR of 1.4 g / 10 min.

In the same manner as in Example 1, this ethylene copolymer composition was molded into an interior container.

Table 4 shows the results of the evaluation of the interior container.

Polyethylene composed of ethylene copolymer composition [II]

Example using resin

Preparation Example 2

Preparation of Catalyst Components

In 100 liters of toluene, 6.3 kg of dried silica was suspended at 250 ° C. for 10 hours and then cooled to 0 ° C. Then, 41 liters of toluene solution of methylaluminoxane (Al = 0.96mol / liter) was added dropwise over 1 hour. The temperature of the system was kept at 0 ° C. during the addition. Subsequently, the said reaction was performed at 0 degreeC for 60 minutes, the temperature was raised to 95 degreeC over 1.5 hours, and reaction was performed at this temperature for 4 hours. The system was then cooled to 60 ° C. and poured off along the supernatant. The solid obtained above was washed twice with toluene and resuspended in 125 liters of toluene. 15 liters of toluene solution of bis (1,3-butylcyclopentadienyl) zirconium dichloride (Zr = 42.7 mmol / liter) was added dropwise to the system at 30 DEG C over 30 minutes, followed by reaction at 30 DEG C for 2 hours. Done. The supernatant was then removed and the residue was washed twice with hexane to give a solid catalyst containing 6.2 mg of zirconium per 1 g of catalyst.

Preparation of Prepolymerization Catalyst

8.5 kg of the solid catalyst obtained above was added to 300 liters of the hexane solution containing 14 mol of triisobutylaluminum, and ethylene prepolymerization was carried out at 35 DEG C for 7 hours to obtain a prepolymer obtained by prepolymerizing 3 g of polyethylene per 1 g of the solid catalyst. .

polymerization

In the continuous fluidized-bed gas phase polymerization reactor, copolymerization of ethylene and 1-hexene was carried out under the conditions of a total pressure of 18 kg / cm ² -G and a polymerization temperature of 80 ° C. In this copolymerization, the prepolymerization catalyst prepared above was continuously supplied to the system at a feed rate of 0.15 mmol / hour (zirconium atom conversion) and at a feed rate of 10 mmol / hour. In order to maintain a constant gas composition during the polymerization, ethylene, 1-hexene, hydrogen, and nitrogen were continuously supplied to the system (gas composition: 1-hexene / ethylene = 0.020, hydrogen / ethylene = 6.6 × 10 ⁻⁴ , ethylene Concentration = 16%).

The yield of ethylene / 1-hexene copolymer (d-1) was 5.0 kg / hour. The density was 0.923g / cm, MFR was 1.1g / 10min, the maximum peak temperature (Tm) of the endothermic curve measured by DSC was 116.8 ° C, the melt tension was 1.5g, and the n-decane soluble fraction at 23 ° C was 0.02% by weight, the number of unsaturated bonds was 0.09 per 1,000 carbon atoms, 0.16 per molecule of the copolymer, and the B value of the 1-hexene distribution in the copolymer chain was 1.02.

Example 10

The ethylene / 1-hexene copolymer (d-1) obtained in manufacture example 2 and the high pressure low density polyethylene (e-2) shown in Table 6 were dry-mixed at the weight ratio 90/10 (d-1 / e-2). 0.05 parts by weight of tri (2,4-di-t-butylphenyl) phosphate as a secondary antioxidant to 100 parts by weight of resin and n-octadecyl-3- (4'-hydroxy-3 ', 0.1 part by weight of 5'-di-t-butylphenyl) propionate and 0.05 part by weight of calcium stearate were mixed as a hydrochloric acid absorbent. Thereafter, the mixture was kneaded at a preset temperature of 180 ° C. using a biaxial conical tapered extruder manufactured by HAK Corporation to obtain an ethylene copolymer composition.

Table 7 shows the physical properties of the ethylene copolymer composition.

The composition was molded into the interior container by the molding method described above.

Table 7 shows the results of the evaluation of the interior container.

Example 11

The ethylene-based air was prepared in the same manner as in Example 10 except that the mixing ratio of the ethylene / 1-hexene copolymer (d-1) and the high pressure low density polyethylene (e-2) was changed to 75/25 (d-1 / e-2). The coalescing composition was prepared. Thereafter, the ethylene-based copolymer composition was molded into the inner container by the molding method described above.

Table 7 shows the melt properties of the ethylenic copolymer composition and the evaluation results of the box-type bag-containing interior container.

Example 12

An ethylene copolymer composition was prepared in the same manner as in Example 10 except that the high pressure low density polyethylene (e-1) shown in Table 6 was used instead of the high pressure low density polyethylene (e-2). Thereafter, the ethylene-based copolymer composition was molded into a box-type bag-containing interior container in the same manner as in Example 10.

Table 7 shows the melt properties of the ethylenic copolymer composition and the evaluation results of the box-type bag-containing interior container.

Comparative Example 8

Ethylene / 1-hexene copolymer (d-) in the same manner as in Production Example 2, except that the titanium catalyst component described in JP-A-63-54289 was used instead of bis (n-butylcyclopentadienyl) zirconium dichloride. 7) was prepared, and the comonomer content was adjusted as shown in Table 5.

Table 5 shows the physical properties of the ethylene / 1-hexene copolymer (d-7).

An ethylene copolymer composition was prepared in the same manner as in Example 10 except that the ethylene / 1-hexene copolymer (d-7) and the high pressure low density polyethylene (e-1) shown in Table 6 were used. In addition, a box-type bag-containing interior container was molded from this composition in the same manner as in Example 10.

Table 7 shows the melt properties of the ethylenic copolymer composition and the evaluation results of the box-type bag-containing interior container.

Comparative Example 9

The ethylene / 1-hexene copolymer (d-7) obtained in the comparative example 8 was shape | molded with the box-type inner container for the same method as Example 10.

The melt | dissolution property of the ethylene / 1-hexene copolymer (d-7), and the evaluation result of the said box-type interior packaging container are shown in Table 7.

Preparation Example 3-5

Ethylene / α-olefin copolymers (d-2, d-3, d-4) were prepared in the same manner as in Production Example 2, except that the type of comonomer and the content of comonomer were changed from those shown in Table 5. .

The physical properties of the ethylene / α-olefin copolymers (d-2, d-3, d-3) are shown in Table 5.

Example 13-15

An ethylene copolymer composition was prepared in the same manner as in Example 10 except for using the ethylene / α-olefin copolymer (d-2, d-3, d-4) and the high pressure low density polyethylene (e-1) shown in Table 6. did. In the same manner as in Example 10, the box-type bag inner container was molded from the ethylene copolymer composition.

Table 7 shows the melt properties of the ethylenic copolymer composition and the evaluation results of the box-type bag-containing interior container.

Preparation Examples 6 and 7

Use of bis (1-methyl-3-n-butylcyclopentadienyl) zirconium dichloride instead of bis (n-butylcyclopentadienyl) zirconium dichloride, except that the comonomer content was adjusted as shown in Table 5. In the same manner as in Preparation Example 2, ethylene / α-olefin copolymers (d-5 and d-6) were prepared, respectively.

Table 5 shows the physical properties of the ethylene / α-olefin copolymers (d-5, d-6).

Examples 16 and 17

An ethylene copolymer composition was prepared in the same manner as in Example 10 except that the ethylene / α-olefin copolymer (d-5 or d-6) and the high pressure low density polyethylene (e-1) shown in Table 6 were used. In the same manner as in Example 10, the box-type bag inner container was molded from the ethylene copolymer composition.

Table 7 shows the melt properties of the ethylenic copolymer composition and the evaluation results of the box-type bag-containing interior container.

Comparative Example 10

An ethylene copolymer composition was prepared in the same manner as in Example 10 except for using the ethylene / 1-hexene copolymer (d-1) obtained in Production Example 2 and the high pressure low density polyethylene (e-3) shown in Table 6. Thereafter, the box-type interior packaging container was molded from the ethylene copolymer composition in the same manner as in Example 10.

Table 7 shows the melt properties of the ethylenic copolymer composition and the evaluation results of the box-type bag-containing interior container.

Comparative Example 11

The ethylene / 1-hexene copolymer (d-1) obtained in Production Example 2 and the high pressure low density polyethylene (e-2) shown in Table 6 were melt mixed at a weight ratio of 40/60 (d-1 / d-2). Prepared an ethylenic copolymer composition in the same manner as in Example 10. In the same manner as in Example 10, the box-type bag-containing interior container was molded from the ethylene copolymer composition.

Table 7 shows the melt properties of the ethylenic copolymer composition and the evaluation results of the box-type bag-containing interior container.

Comparative Example 12

A box-type interior packaging container was prepared in the same manner as in Example 10 except that the high pressure low density polyethylene (e-2) shown in Table 6 was used instead of the ethylene copolymer composition.

The melt | dissolution property of an ethylene-type copolymer (e-1), and the evaluation result of the said box-type interior packaging container are shown in Table 7.

Preparation Example 8

Preparation of Catalyst Components

10.0 kg of dried silica was suspended in 154 liters of toluene at 250 ° C. for 10 hours and then cooled to 0 ° C. Then, 57.5 liters of toluene solution of methylaluminoxane (Al = 1.33 mol / liter) was added dropwise over 1 hour. The temperature of the system was kept at 0 ° C. during the addition. Subsequently, the said reaction was performed at 0 degreeC for 30 minutes, the temperature was raised to 95 degreeC over 1.5 hours, and reaction was performed at this temperature for 20 hours. The system was then cooled to 60 ° C. and poured off along the supernatant. The solid obtained above was washed twice with toluene and resuspended in 100 liters of toluene. To this system was added dropwise 16.8 liters of toluene solution of bis (1-methyl-3-n-butylcyclopentadienyl) zirconium dichloride (Zr = 27.0 mmol / liter) dropwise at 80 DEG C over 30 minutes, and for 2 hours. Reaction was performed at 80 degreeC. The supernatant was then removed and the residue was washed twice with hexane to give a solid catalyst containing 3.5 mg of zirconium per 1 g of catalyst.

Preparation of Prepolymerization Catalyst

870 g of the above obtained solid catalyst and 260 g of 1-hexene were added to 87 liters of the hexane solution containing 2.5 mol of triisobutylaluminum, and 10 g of polyethylene was prepolymerized per 1 g of the solid catalyst by ethylene prepolymerization at 35 DEG C for 5 hours. A prepolymerization catalyst was obtained.

polymerization

Copolymerization of ethylene and 1-hexene in a continuous fluidized-bed gas phase polymerization reactor was carried out under conditions of a total pressure of 18 kg / cm ² -G and a polymerization temperature of 75 ° C. In this copolymerization, the prepolymerization catalyst prepared above was continuously supplied to the system at a feed rate of 0.15 mmol / hr (zirconium atom conversion) and at a feed rate of 10 mmol / hr. In order to maintain a constant gas composition during polymerization, ethylene, 1-hexene, hydrogen, and nitrogen were continuously supplied to the system (gas composition: 1-hexene / ethylene = 0.034, hydrogen / ethylene = 1.7 × 10 ⁻⁴ , ethylene Concentration = 20%).

The yield of ethylene / 1-hexene copolymer (f-1) was 5.8 kg / hour. Density is 0.908g / cm ³ , MFR is 0.77g / 10min, the maximum peak temperature of the endothermic curve measured by DSC is 93.6 ℃, n-decane soluble fraction is 0.51% by weight at 23 ℃, unsaturated bond water Was 0.08 per 1000 carbon atoms and 0.70 per molecule of the copolymer.

Example 18

Ethylene produced in the same manner as in Preparation Example 8 except that the ethylene / 1-hexene copolymer (f-1) (density: 0.908 g / cm ³ ) and the comonomer content obtained in Preparation Example 8 were adjusted as shown in Table 8. The / 1-hexene copolymer (g-1) was melt-kneaded at a weight ratio of 60/40 (f-1 / g-1) to obtain an ethylene / 1-hexene copolymer composition (L-1).

Table 9 shows the physical properties of the ethylene / 1-hexene copolymer composition (L-1).

The ethylene / 1-hexene copolymer composition (L-1) and the high pressure low density polyethylene (H-1) shown in Table 10 were dry mixed at a weight ratio of 90/10 (L-1 / H-1). 0.05 part by weight of tri (2,4-di-t-butylphenyl) phosphate as a secondary antioxidant to 100 parts by weight of the resultant mixture, n-octadecyl-3 (4'-hydroxy-3 ', 0.1 weight part of 5'-di-t-butylphenyl) propionate and 0.05 weight part of calcium stearate were mix | blended as a hydrochloric acid absorbent. Thereafter, the mixture was kneaded at a set temperature of 180 ° C. using a biaxial conical tapered extruder manufactured by HAK Corporation to obtain an ethylene copolymer composition.

Table 11 shows the melt properties of the ethylene copolymer composition.

By this method, the box-type bag-containing interior container was manufactured with this composition. Table 11 shows the evaluation results of the box-type inner container.

Example 19

Ethylene / 1-hexene copolymer (f-2) (density: 0.909 g / cm ³ ) and ethylene / 1- which were each prepared in the same manner as in Production Example 8 except that the comonomer contents were adjusted as shown in Table 8 The hexene copolymer (g-2) (density: 0.943 g / cm ³ ) was melt kneaded at a weight ratio of 70/30 (f-2 / g-2) to give an ethylene / 1-hexene copolymer composition (L-2). Got it.

Table 9 shows the physical properties of the ethylene / 1-hexene copolymer composition (L-2).

An ethylene copolymer composition was prepared in the same manner as in Example 18 except that the ethylene / 1-hexene copolymer composition (L-2) was used. Thereafter, the above-mentioned composition was formed in a box-type bag inner container in the same manner as in Example 18.

Table 11 shows the results of the evaluation of the interior container.

Example 20

The ethylene / 1-hexene copolymer (f-3) (density: 0.910 g / cm ³ ) and ethylene / 1- which were each prepared similarly to manufacture example 8 except having adjusted the comonomer content as shown in Table 8. a: (0.946g / cm ³ density), the weight ratio of 60/40 (f-3 / g- 3) by melt-kneading, an ethylene / 1-hexene copolymer composition (l-3) as hexene copolymer (g-3) Got it.

Table 9 shows the physical properties of the ethylene / 1-hexene copolymer composition (L-3).

An ethylene copolymer composition was prepared in the same manner as in Example 18 except that the ethylene / 1-hexene copolymer composition (L-3) was used instead of the ethylene / 1-hexene copolymer composition (L-1). Thereafter, the above-mentioned composition was formed in a box-type bag inner container in the same manner as in Example 18.

Table 11 shows the results of the evaluation of the interior container.

Comparative Example 13

Instead of bis (1-methyl3-nbutylcyclopentadienyl) zirconium dichloride, the titanium catalyst component described in JP-A-63-54289 is used, and triethylaluminum is used instead of methylaluminum noxane. And ethylene / 1-hexene copolymer (f-4) (density; 0.915 g / cm ³ ) prepared in the same manner as in Production Example 8, except that the gas composition was changed as shown in Table 8. The copolymer (g-4) (density: 0.933 g / cm ³ ) was melt kneaded at a weight ratio of 60/40 (f-4 / g-4) to obtain an ethylene / 1-hexene copolymer composition (L-4).

Table 9 shows the physical properties of the ethylene / 1-hexene copolymer composition (L-4).

An ethylene copolymer composition was prepared in the same manner as in Example 18 except that the ethylene / 1-hexene copolymer composition (L-4) was used instead of the ethylene / 1-hexene copolymer composition (L-1). Thereafter, the above-mentioned composition was formed in a box-type bag inner container in the same manner as in Example 18.

Table 11 shows the results of the evaluation of the interior container.

Table 11 shows that the ethylene copolymer composition obtained in Comparative Example 13 has almost the same density and MFR but lower moldability as compared with the ethylene copolymer composition of Example 18.

Comparative Example 14

The ethylene / 1-hexene copolymer composition (L-4) obtained in Comparative Example 13 was formed in a box-type bag inner container in the same manner as in Example 18.

Table 11 shows the results of the evaluation of the interior container.

Example 21

The ethylene / 1-hexene copolymer composition (L-1) prepared in Example 18 and the high pressure low density polyethylene (H-1) used in Example 18 were melted at a weight ratio of 70/30 (L-1 / H-1). Except kneading, an ethylene copolymer composition was prepared in the same manner as in Example 18. Thereafter, the composition was molded into a box-type inner container in the same manner as in Example 18.

Table 11 shows the physical properties of the ethylene-based copolymer composition and the evaluation results of the inner bag for the box type bag.

Comparative Example 15

The ethylene / 1-hexene copolymer composition (L-1) prepared in Example 18 and the high pressure low density polyethylene (H-1) used in Example 18 were melted at a weight ratio of 50/50 (L-1 / H-1). Except kneading, an ethylene copolymer composition was prepared in the same manner as in Example 18. Thereafter, the composition was molded into a box-type inner container in the same manner as in Example 18.

Table 11 shows the physical properties of the ethylene-based copolymer composition and the evaluation results of the inner bag for the box type bag.

Table 11 shows that Comparative Example 15 was excellent in moldability but poor in flex resistance.

Comparative Example 16

An ethylene copolymer composition was prepared in the same manner as in Example 18 except that only the high pressure low density polyethylene (H-1) was used. Thereafter, the composition was molded into a box-type inner container in the same manner as in Example 18.

Table 11 shows the evaluation results of the box-type inner container.

From Table 11, it can be seen that Comparative Example 16 has excellent moldability but poor pinhole resistance and bending resistance.

The polyethylene inner container for box type bags according to the present invention is formed of polyethylene having high thermal stability and moldability, and exhibits excellent blocking resistance, pinhole resistance and bending resistance.

The polyethylene inner container for a box bag is excellent in handling, and the half of the container can be folded over the other half.

The container for storing and transporting fluids according to the present invention is filled with the fluids, empty and folded even if repeated 90,000 times, for example, using the box-type polyethylene bag for packaging according to the present invention There is no rupture.

The method for transporting fluids according to the present invention has the effect of low storage and transport costs since the flexible internal container can be repeatedly used 90,000 times without being replaced, for example.

Claims (1)

In the repeated conveying method of the flow material using the same vessel, the method a) in the first position (i) the blocking force is 1.0 g / cm or less; (ii) the number of pinholes formed on an area of 20.5 cm x 28.0 cm after repeated twisting 2,000 times in a film using a gelbo bending tester was 2 or less; (iii) a flexible, thin-walled flexible interior container made of polyethylene resin of an ethylene-based copolymer having a bending count of 90.000 or more, measured according to JIS P-8115; b) unfolding the inner container and containing it in a sufficiently strong portable outer container to form a boxed bag; c) filling the inner container with fluid, and sealing the inner and outer containers to prevent leakage of the fluid contained in the inner bag; d) conveying a boxed back container filled in a second position away from the first position; e) opening the exterior and interior containers to empty the flow material of the interior containers for use in the second position; f) removing the empty inner container from the outer container; g) after folding the inner container together, the folded inner container is transported from the second position to the first position or the third position; h) repeating steps b) to g); Steps b) to g) are repeated without replacing the flexible inner container. How to transport fluids.