JP7005901B2 - Resin composition for intermediate layer, packaging film and liquid packaging bag - Google Patents

Description

The present invention relates to a resin composition for an intermediate layer, a packaging film, and a liquid packaging bag using the same. More specifically, the present invention is a packaging film having at least a base material layer, an intermediate layer, and a sealant layer, and a resin composition for the intermediate layer. Regarding goods and liquid packaging bags using them.
In particular, the present invention provides extrusion processability (reduction of mechanical load, film processability, laminating processability, etc.) and automatic filling suitability when the packaging material is used as a packaging bag for liquids and viscous bodies in an automatic filling machine. In order to satisfy various performances (heat seal strength, heat seal temperature range, heat seal temperature, hot tack property, etc.) and product characteristics (appearance, pressure resistance strength, bag breaking strength, piercing strength, etc.), pressure resistance is used as an intermediate layer. High strength and heat seal strength enable high-speed filling in a wide sealing temperature range from low temperature to high temperature, satisfying the above automatic filling suitability and at the same time satisfying extrusion processing suitability such as reduction of mechanical load. It is an improved version.

Conventionally, as a base material for packaging, a polyamide resin, a polyethylene terephthalate resin, a polypropylene resin, etc., which are excellent in transparency and mechanical strength, have been used. However, since the heat-sealing temperature is high and the packaging speed cannot be increased, the film shrinks during heat-sealing and the appearance of the package deteriorates, and the heat-sealing strength is low. The material is rarely used alone, and usually a composite film provided with a heat seal layer is used.
For example, liquids and viscous bodies, as well as liquids containing solid substances such as fibers and powders as insoluble substances, and viscous bodies and other liquid packaging substrates have a surface made of polyamide resin, polyethylene terephthalate resin, paper, aluminum foil, and the like. Known are composite films in which a sealant layer is provided on a base material layer, or packaging films obtained by laminating various intermediate layers on a base material and further laminating a sealant layer on the composite film.

Initially, low-density polyethylene (LDPE), ethylene-vinyl acetate copolymer (EVA), etc. were used as the sealant layer film of such a composite film, but the LDPE film has high-speed formability (processability). Although it is excellent in low temperature heat sealing property, heat resistance, hot tack property, etc., EVA is excellent in low temperature heat sealing property, but has drawbacks in heat resistance, hot tack property, etc.

As an improvement to these, in Patent Document 1, a random copolymer weight of ethylene having a specific physical property and a density of 0.910 to 0.940 g / cm ³ and an α-olefin having 4 to 10 carbon atoms on the base material layer is used. A composite film in which a sealant layer composed of a blend composition of coalesced and high-pressure low-density polyethylene (hereinafter, may be abbreviated as HPLD) is laminated has been proposed.
Further, in Patent Document 2, a specific temperature-increasing elution fraction (hereinafter referred to as "hereinafter,") produced by a metallocene catalyst as a laminated composition in which the heat-sealing strength and hot-tack property of the composite film are maintained and the low-temperature heat-sealing property is further improved is maintained. A copolymer of ethylene having characteristics (sometimes abbreviated as TREF) and an α-olefin having 3 to 18 carbon atoms, and a blend composition of a specific low-density polyethylene have been proposed, or the same applies to Patent Document 3. As a polyethylene composition for a composite film, ethylene having a density of 0.880 to 0.930 g / cm ³ and a molecular weight distribution of 1.5 to 4.0 and α-olefin having 4 to 10 carbon atoms produced by a metallocene catalyst. A composition comprising a random copolymer of and high-pressure low-density polyethylene has been proposed.

The sealant layer composed of the above-mentioned blend composition of the specific ethylene-α-olefin random copolymer and the high-pressure low-density polyethylene has heat-sealing strength and hot tackiness as compared with the conventional low-density polyethylene sealant layer. Etc. are excellent. However, in the case of liquid packaging such as soup, sauce, sauce, noodle soup, etc., two rotations are performed for vertical and horizontal sealing of the composite film (packaging material) using an automatic filling machine such as a die roll type. It is sandwiched between rolls and sealed to form a filling bag. When a sealant composed of these blend compositions is used in such a heat-sealing method, there are problems that the heat-sealing portion becomes thin, bag breakage occurs, and the base material and the sealant layer are peeled off. rice field.

In order to solve such a problem, Patent Document 4 proposes a multilayer film in which an intermediate layer is provided between a base material and a sealant. In such a multilayer film composed of an outer layer (A) / an intermediate layer (B) / an inner layer (C), an ethylene-α-olefin copolymer (1) and an intermediate layer (B) are added to the outer layer (A) and the inner layer (C). ) With an ethylene-α-olefin copolymer (2) having a density at least 0.003 g / cm ³ higher than that of the ethylene-α-olefin copolymer (1), and an ethylene-α-olefin copolymer (1). It is proposed to use a resin composition consisting of an ethylene-α-olefin copolymer (3) having the same density or a density lower than that and a low-density polyethylene obtained by a high-pressure radical polymerization method to prepare a coextruded multilayer film for bonding. Has been done.

Further, in Patent Document 5, at least the base material layer, the intermediate layer and the sealant layer are laminated in this order as the intermediate layer of the multi-layered film, that is, the linear low density polyethylene (A) and the high pressure method low density polyethylene (B). The linear low-density polyethylene (A) comprises a resin composition having a mixing ratio [(A) / (B)] of 70/30 to 40/60, and the linear low-density polyethylene (A) is α- with 4 or more carbon atoms. It is a copolymer with olefin, its melt flow rate is 1 to 50 g / 10 minutes, its density is 0.890 to 0.930 g / cm ³ , and Mw / Mn showing the molecular weight distribution is 1.5. It has been proposed to use polyethylene having a melt tension of about 4.0 and the high-pressure low-density polyethylene (B) having a melt tension of 2 g or more.

Further, in Patent Document 6, at least the base material layer, the intermediate layer and the sealant layer are linear low-density polyethylene (A) 50 to 95 weights produced from a metallocene catalyst as an intermediate layer of a multi-layered film laminated in this order. % And 50-5% by weight of high pressure low density polyethylene (B) has been proposed to be used.

Further, Patent Documents 7 and 8 describe a sealant layer made of linear low-density polyethylene (L-LDPE), an intermediate layer made of L-LDPE having a higher density than the sealant layer, and a base film made of a biaxially stretched film. A packaging film having a three-layer structure extruded with layers has been proposed.

Further, Patent Document 9 describes a laminate in which a base film, a support layer, and a sealant layer are laminated in order, and the support layer is polymerized using a Ziegler-Natta-based catalyst or a metallocene-based single-site catalyst. A laminate composed of a linear low-density polyethylene resin and a composition in which a sealant layer is a blend of two or more specific resins has been proposed.

However, when manufacturing a film using an automatic filling device, it is necessary to adjust the setting conditions of the filling device in order to cope with differences in various contents and base materials. In the conventional film as disclosed, there is a problem that the permissible range for each packaging material is not sufficient, and it becomes necessary to search for filling conditions each time, which causes further improvement in filling suitability. I was asked.

Special Fair 02-004425 Gazette Japanese Unexamined Patent Publication No. 07-026079 Japanese Unexamined Patent Publication No. 8-269270 Japanese Unexamined Patent Publication No. 10-323948 Japanese Unexamined Patent Publication No. 11-010809 Japanese Unexamined Patent Publication No. 2001-009997 Japanese Unexamined Patent Publication No. 2008-302977 Japanese Unexamined Patent Publication No. 2005-289471 Japanese Unexamined Patent Publication No. 2004-223728

An object of the present invention is to use a resin composition for an intermediate layer which is excellent in heat sealability and productivity and can be filled at high speed in a wide temperature range from low temperature to high temperature in view of the above-mentioned problems of the prior art. The purpose is to provide packaging films and liquid packaging bags.

As a result of diligent studies to solve the above problems, the present inventors have found that the above problems can be solved by using an ethylene-based polymer having a specific composition and physical properties for the intermediate layer, and complete the present invention. It came to.
That is, the gist of the present invention lies in the inventions of the following items.

According to the first invention of the present application, it is a resin composition for an intermediate layer used for an intermediate layer (II) of a packaging film having at least a base material layer (I), an intermediate layer (II) and a sealant layer (III). The ethylene-based resin composition is a mixture of an ethylene-based polymer satisfying the following conditions (A-1) to (A-4) and a high-pressure radical method low-density polyethylene so as to be 100% by weight. Provided is a resin composition for an intermediate layer, which is characterized by satisfying the conditions (B-1) and (B-2).
Conditions for ethylene polymer (A);
(A-1) The melt flow rate (MFR) at 190 ° C. under a 2.16 kg load is 0.1 g to 100 g / 10 minutes.
(A-2) The density is 0.895 to 0.940 g / cm ³ .
(A-3) The ratio (Y) of the components eluted at 0 ° C. or lower by the temperature rise elution fraction (TREF) is less than 0.8% by weight.
(A-4) The lowest value (g _L ) between the molecular weights of 100,000 and 1,000,000 in the branch index g'measured by a GPC measuring device combining a differential refractometer, a viscosity detector, and a light scattering detector. Is 0.20 to 0.40.
Conditions for the entire composition;
(B-1) The melt flow rate (MFR) at 190 ° C. under a 2.16 kg load is 1 to 50 g / 10 minutes.
(B-2) The density is 0.900 to 0.935 g / cm ³ .

According to the second invention of the present application, there is provided a resin composition for an intermediate layer, wherein the ethylene-based polymer of the first invention satisfies the following condition (A-5).
(A-5) The value (gm) of the branch index _g'at a molecular weight of 100,000 is 0.50 to 0.75.

According to the third invention of the present application, there is provided a resin composition for an intermediate layer, wherein the ethylene-based polymer of the first or second invention satisfies the following condition (A-6). ..
(A-6) The ratio (X) of the components eluted at 85 ° C. or higher by the temperature rise elution fraction (TREF) exceeds 1% by weight and is less than 70% by weight.

According to the fourth invention of the present application, the ethylene-based polymer according to any one of the first to third inventions is characterized in that the following condition (A-7) is satisfied. Is provided.
(A-7) The molecular weight distribution Mw / Mn measured by gel permeation chromatography (GPC) is 3.0 to 10.0.

According to the fifth invention of the present application, the resin composition for an intermediate layer is characterized in that the ethylene-based polymer according to any one of the above-mentioned first to fourth inventions satisfies the following condition (A-8). Provided.
(A-8) The molecular weight distribution Mz / Mw measured by GPC is 2.0 to 9.0.

According to the sixth invention of the present application, the ethylene-based polymer according to any one of the first to fifth inventions is characterized in that the following condition (A-9) is satisfied. Is provided.
(A-9) Percentage of components whose molecular weight is equal to or greater than the weight average molecular weight among the components eluted at a temperature or lower at which the elution amount determined from the integrated elution curve measured by cross fractionation chromatography (CFC) is 50 wt% (A-9). W ₂ ) and the sum of the proportions (W ₃ ) of the components whose molecular weight is less than the weight average molecular weight among the components eluted at a temperature higher than the temperature at which the elution amount obtained from the integrated elution curve is 50 wt% (W ₂ + W). ₃ ) is more than 40% by weight and less than 80% by weight.

According to the seventh invention of the present application, the ethylene-based polymer according to any one of the first to sixth inventions is characterized in that the following condition (A-10) is satisfied. Is provided.
(A-10) Percentage of components having a molecular weight equal to or higher than the weight average molecular weight among the components eluted at a temperature higher than the temperature at which the elution amount obtained from the integrated elution curve measured by W ₂ and CFC is 50 wt% (W). The difference (W2 _- W4) in ₄ ) is greater than _-4 % by weight and less than 30% by weight.

According to the eighth invention of the present application, it is characterized by being the ethylene homopolymer according to any one of the above-mentioned first to seventh inventions or a copolymer of ethylene and an α-olefin having 3 to 10 carbon atoms. A resin composition for an intermediate layer is provided.

According to the ninth invention of the present application, the ethylene-based polymer according to any one of the above-mentioned first to eighth inventions is produced by an olefin polymerization catalyst containing the components (i), (ii) and (iii). A resin composition for an intermediate layer is provided.
Component (i): Cross-linked cyclopentadienyl indenyl compound containing a transition metal element having a five-membered ring structure substituent on the indenyl ring Component (ii): Cationic metallocene compound by reacting with the compound of component (A) Compound component (iii): Inorganic compound carrier

According to the tenth invention of the present application, a packaging film having at least a base material layer (I), an intermediate layer (II) and a sealant layer (III), and a resin for an intermediate layer used for the intermediate layer (II). As the composition, a packaging film characterized by using the resin composition for an intermediate layer according to any one of the first to ninth inventions is provided.
According to the eleventh invention of the present application, the intermediate layer (II) and the sealant layer (III) according to the tenth invention are laminated by an extrusion lamination method or a coextrusion lamination method for packaging. Film is provided.

According to the twelfth invention of the present application, there is provided a liquid packaging film, wherein the packaging film according to the tenth or eleventh invention is a film for packaging a content containing a liquid. ..
According to the thirteenth invention of the present application, a liquid packaging bag formed in a bag shape using the packaging film according to the tenth or eleventh invention is provided.

The resin composition for an intermediate layer of the present invention has excellent low-temperature sealing properties when used as an intermediate layer for liquid and / or viscous packaging materials, and enables high-speed filling in a wide temperature range. Further, as a packaging film using the resin composition for an intermediate layer as an intermediate layer, it is possible to provide a packaging film and a liquid packaging bag having excellent sealing strength, pressure resistance and high-speed filling property.

It is a general example of a graph showing baselines and intervals of a chromatogram used in gel permeation chromatography (GPC) methods. It is a general example of a graph showing the relationship between the branch index (g') and the molecular weight (M) calculated from the GPC-VIS measurement (branching structure analysis). It is a general example of the graph which shows the elution temperature distribution of the elution amount by the temperature rise elution fraction (TREF). It is a graph which shows the elution amount about the elution temperature and the molecular weight measured by the cross fractionation chromatography (CFC) method as a contour chart. It is a graph which shows the relationship between the elution temperature measured by the cross fractionation chromatography (CFC) method, and the elution ratio (wt%) at each elution temperature.

The present invention is an ethylene-based copolymer newly developed by the present applicant in recent years, that is, an ethylene-based copolymer having a specific molecular structure, that is, having a density with a specific MFR and having a small amount of low-temperature elution components due to temperature-raising elution fractionation (TREF). The present invention relates to a resin composition for an intermediate layer made of an ethylene-based polymer having a highly developed branched structure characterized by a branching index (g'), and a packaging film produced by using the same for the intermediate layer. It is a thing.
Hereinafter, the conditions (A-1) to (A-10) that characterize the resin composition for the intermediate layer used in the present invention will be described in detail for each item.

1. 1. Ethylene-based polymer used in the present invention The ethylene-based polymer used in the present invention is basically characterized by satisfying all of the conditions (A-1) to (A-4) described below.
1-1. Condition (A-1)
The melt flow rate (MFR; 190 ° C., under a load of 2.16 kg) of the ethylene polymer of the present invention is 0.1 to 100 g / 10 minutes, preferably 0.2 to 50 g / 10 minutes, and more preferably 0. It is 5 to 30 g / 10 minutes, more preferably 1 to 20 g / 10 minutes.

When the MFR is in this range, the processing characteristics at the time of extrusion laminating are excellent. On the other hand, if the MFR is less than 0.1 g / 10 minutes, there arises a problem that a load is applied to the machine during extrusion laminating. If the MFR is larger than 100 g / 10 minutes, the neck-in during processing becomes large, which not only deteriorates the yield of the product but also causes smoke and odor, which is not preferable. In the present invention, the MFR of the ethylene / α-olefin copolymer is based on JIS K7210 "Test method for melt mass flow rate (MFR) and melt volume flow rate (MVR) of plastic-thermoplastic plastic". , 190 ° C, 21.18N (2.16kg) means the value measured under the condition of load.
The MFR can be adjusted by changing the amount of chain transfer agent (hydrogen, etc.) coexisting during ethylene polymerization or by changing the polymerization temperature, increasing the amount of hydrogen or increasing the polymerization temperature. By doing so, it can be increased.

1-2. Condition (A-2)
The density of the ethylene-based polymer used in the present invention is 0.895 to 0.940 g / cm ³ .
If the density is higher than the above range, the low temperature heat sealing property is inferior. On the other hand, if the density is lower than the above range, it tends to foam when sealed at a high temperature.

In the present invention, the density of the ethylene-based polymer is a value measured by the following method.
The pellets were hot pressed to prepare a 2 mm thick press sheet, which was placed in a beaker having a capacity of 1,000 ml, filled with distilled water, covered with a watch glass, and heated with a mantle heater. After boiling the distilled water for 60 minutes, the beaker was placed on a wooden table and allowed to cool. At this time, the boiling distilled water after boiling for 60 minutes was set to 500 ml, and the time until the room temperature was adjusted was adjusted so as not to be 60 minutes or less. In addition, the test sheet was immersed in a substantially central part of the water so as not to come into contact with the beaker and the water surface. After annealing the sheet under the conditions of 23 ° C. and 50% humidity within 16 hours or more and 24 hours or less, punching is performed so that the length and width are 2 mm, and the test temperature is 23 ° C. And the measurement method of specific gravity ”.

1-3. Condition (A-3)
In the ethylene polymer of the present invention, in addition to the above conditions (A-1) and (A-2), the ratio (Y) of the components eluted at 0 ° C. or lower by the temperature-increasing elution fractionation (TREF) is 0.8. Less than% by weight, preferably less than 0.7% by weight, more preferably less than 0.6% by weight. The temperature-increasing elution separation (TREF) is a conventional means for separating a polymer according to its amorphousness and crystallinity.
When the Y value is 0.8% by weight or more, the low molecular weight component and the low density component contained in the ethylene-based polymer increase, which may deteriorate the mechanical strength of the packaging film, which is not preferable. The Y value is 0% by weight or more.

[Measurement conditions for TREF]
The sample is dissolved in orthodichlorobenzene (with 0.5 mg / mL BHT) at 140 ° C. to prepare a solution. After introducing this into a TREF column at 140 ° C., it is cooled to 100 ° C. at a temperature lowering rate of 8 ° C./min, subsequently cooled to 40 ° C. at a temperature lowering rate of 4 ° C./min, and then lowered to 1 ° C./min. Cool to -15 ° C at speed and hold for 20 minutes.
Then, the solvent orthodichlorobenzene (containing 0.5 mg / mL BHT) was flowed through the column at a flow rate of 1 mL / min, and the components dissolved in orthodichlorobenzene at −15 ° C. were eluted in the TREF column for 10 minutes. Next, the column is linearly heated to 140 ° C. at a heating rate of 100 ° C./hour to obtain an elution curve. At this time, the amount of the component eluted between −15 ° C. and 0 ° C. (W ≦ 0 ° C.) is defined as Y (unit: wt%), and the amount of the component eluted between 85 ° C. and 140 ° C. (W ≧ 85 ° C.) ) Is X (unit: wt%). FIG. 3 shows a general example of a graph showing the elution temperature distribution of the elution amount by the heated elution fraction (TREF).

The equipment used is as follows.
(TREF section)
TREF column: 4.3 mmφ x 150 mm Stainless steel column Filling: 100 μm Surface inert treatment Glass beads Heating method: Aluminum heat block Cooling method: Pelche element (Cooling of Pelche element is water cooling) Temperature distribution: ± 0.5 ° C temperature controller : Chino Digital Program Controller KP1000 (Valve Oven) Heating method: Air bath type Oven Measurement temperature: 140 ° C Temperature distribution: ± 1 ° C Valve: 6-way valve / 4-way valve (sample injection part)
Injection method: Loop injection method Injection amount: Loop size 0.1 ml Injection inlet heating method: Aluminum heat block Measurement temperature: 140 ° C
(Detection unit)
Detector: Fixed wavelength infrared detector FOXBORO, MIRAN, 1A Detection wavelength: 3.42 μm High temperature flow cell: Micro flow cell for LC-IR, optical path length 1.5 mm, window shape 2φ x 4 mm oval, synthetic sapphire window Plate measurement temperature: 140 ° C
(Pump section)
Liquid feed pump: SSC-3461 pump manufactured by Senshu Kagaku Co., Ltd. (measurement conditions)
Solvent: Orthodichlorobenzene (with 0.5 mg / mL BHT) Sample concentration: 5 mg / mL Sample injection volume: 0.1 mL Solvent flow rate: 1 mL / min

1-4. Condition (A-4)
The ethylene polymer in the present invention is measured by a GPC measuring device in which a differential refractometer, a viscosity detector, and a light scattering detector are further combined in addition to the above conditions (A-1) to (A-3). The minimum value (g _L ) between the molecular weights of 100,000 and 1,000,000 in the branch index g'is 0.20 to 0.40, preferably 0.25 or more and less than 0.40, and more preferably 0.27 or more. It is less than 0.40.
Note that g'is a measure of the degree of existence of long-chain branches, and ( _GL ) can be achieved by introducing a certain amount of long-chain branches into an ethylene-based polymer.
If the g _L value is larger than 0.40, the effect of improving the moldability and fluidity may be reduced, which is not preferable. When the g _L value is smaller than 0.20, the moldability and fluidity are improved, but the material strength may be lowered, which is not preferable. In the present invention, the g _L value of the ethylene polymer is a method for evaluating the amount of long-chain branching using the molecular weight distribution curve calculated from the following GPC-VIS measurement and the branching index (g').

[Branch structure analysis by GPC-VIS]
A Waters GPCV2000 was used as a GPC apparatus equipped with a differential refractometer (RI), a viscosity detector (Viscometer) and a light scattering detector. Further, as the light scattering detector, DAWN-E manufactured by Wyatt Technology Co., Ltd., which is a multi-angle laser light scattering detector (MALLS), was used. The detector was connected in the order of MALLS, RI, and Viscometer. The mobile phase solvent is 1,2,4-trichrobendene (addition of the antioxidant Irganox 1076 at a concentration of 0.5 mg / mL). The flow rate is 1 mL / min. As the column, two GMHHR-H (S) and HT manufactured by Tosoh Corporation were connected and used. The temperature of the column, the sample injection part and each detector is 140 ° C. The sample concentration was 1 mg / mL. The injection volume (sample loop volume) is 0.2175 mL.
The data processing software ASTRA (version 4.73.04) attached to MALLS was used to calculate the absolute molecular weight (M) obtained from MALLS, the radius of inertia squared (Rg), and the ultimate viscosity ([η]) obtained from Viscometer. , The calculation was performed with reference to the following documents.

References:
1. 1. Developments in polimer cultivation, vol. 4. Essex: Applied Science; 1984. Chapter1.
2. 2. Polymer, 45, 6495-6505 (2004)
3. 3. Macromolecules, 33, 2424-2436 (2000)
4. Macromolecules, 33, 6945-6952 (2000)

[Calculation of branch index (g'), etc.]
The branching index (g') is calculated as a ratio (ηbranch / ηlin) between the limit viscosity (ηbranch) obtained by measuring the sample with the Viscometer and the limit viscosity (ηlin) separately obtained by measuring the linear polymer. do.
When a long chain branch is introduced into a polymer molecule, the radius of inertia becomes smaller compared to a linear polymer molecule of the same molecular weight. Since the intrinsic viscosity decreases as the radius of inertia decreases, the ratio (ηbranch / ηlin) of the intrinsic viscosity (ηbranch) of the branched polymer to the intrinsic viscosity (ηlin) of the linear polymer having the same molecular weight becomes smaller as the long-chain branching is introduced. It will become. Therefore, when the branch index (g'= ηbranch / ηlin) becomes a value smaller than 1, it means that a branch is introduced, and as the value becomes smaller, the introduced long-chain branch increases. Means that. In particular, in the present invention, as the absolute molecular weight obtained from MALLS, the lowest value of the above g'within a molecular weight of 100,000 to 1,000,000 is calculated as g _L.
FIG. 2 shows an example of the analysis result by the above GPC-VIS. FIG. 2 represents the ramification index (g') at the molecular weight (M) obtained from MALLS. Here, as the linear polymer, linear polyethylene Standard Reference Material 1475a (National Institute of Standards & Technology) was used.

1-5. Condition (A-5)
In addition to the above conditions (A-1) to (A-4), the ethylene-based polymer used in the present invention has a branching index g'measured in the same manner as the above-mentioned _GL at a molecular weight of 100,000. The value (g _m ) is 0.50 to 0.75, preferably 0.55 or more and less than 0.75, more preferably 0.55 to 0.73, still more preferably 0.58 to 0.72, and particularly preferably. It is 0.60 to 0.71.
Within this range, the melt processability and fluidity are further improved, and the effect of reducing the amount of electric power is increased, which is a suitable condition. If the _gm value is larger than 0.75, the effect of improving the molding processability and the fluidity becomes small, which may not be preferable. When the mg value is smaller than _0.50 , the moldability and fluidity are improved, but the material strength is lowered, which may not be preferable.

1-6. Condition (A-6)
In addition to the above conditions (A-1) to (A-5), the ethylene-based polymer used in the present invention further comprises a component that elutes at 85 ° C. or higher as measured by TREF, similarly to the above-mentioned Y value. The proportion (X) is greater than 1% by weight, less than 70% by weight, preferably more than 2% by weight, less than 50% by weight, more preferably more than 2% by weight, less than 36% by weight, still more preferably 3% by weight. Exceeds, less than 33% by weight, most preferably more than 3% by weight and less than 10% by weight.
Within this range, hot tackiness and extrusion laminating workability are improved. When the X value is 1% by weight or less, the hot tackiness is lowered and the extrusion laminating workability is also lowered, which is not preferable. If the X value is 70% by weight or more, the low temperature sealing property deteriorates, which is not preferable.

1-7. Condition (A-7)
The preferred range of the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the ethylene polymer used in the present invention is 3.0 to 10.0, preferably 3.5 to 9. It is 0.0, more preferably 4.0 to 8.0, and even more preferably 4.5 to 8.0. If Mw / Mn is less than 3.0, the effect of improving molding processability, particularly melt fluidity and neck-in, will be small and should be avoided.
If Mw / Mn is larger than 10.0, the moldability, especially the high-speed moldability, may deteriorate. In the present invention, Mw and Mn of the ethylene polymer are those measured by the gel permeation chromatography (GPC) method.

[GPC method measurement]
The measured holding capacity is measured by the GPC method, and the conversion from the measured holding capacity to the molecular weight is performed using a calibration curve made of standard polystyrene prepared in advance. The standard polystyrenes used are all the following brands manufactured by Tosoh Corporation. F380, F288, F128, F80, F40, F20, F10, F4, F1, A5000, A2500, A1000.
A calibration curve is created by injecting 0.2 mL of solution dissolved in ODCB (containing 0.5 mg / mL BHT) so that each is 0.5 mg / mL. The calibration curve uses a cubic equation obtained by approximating with the least squares method. For conversion to molecular weight, a general-purpose calibration curve is used with reference to "Size Exclusion Chromatography" (Kyoritsu Shuppan) by Sadao Mori. The following numerical values are used for the viscosity formula [η] = K × M ^α used at that time.
PS: K = 1.38 × 10 ^-4 , α = 0.7
PE: K = 3.92 × 10 ^-4 , α = 0.733

The measurement conditions of GPC are as follows.
Device: Waters GPC (ALC / GPC 150C) Detector: FOXBORO MIRAN ・ 1A ・ IR detector (Measurement wavelength: 3.42 μm) Column: Showa Denko AD806M / S (3) Mobile phase solvent: o-dichlorobenzene Measurement temperature: 140 ° C. Flow velocity: 1.0 ml / min Injection amount: 0.2 ml
Sample Preparation: Samples are prepared with ODCB (containing 0.5 mg / mL BHT) to prepare a 1 mg / mL solution and dissolved at 140 ° C. for about 1 hour.
The baseline and section of the obtained chromatogram are as illustrated in FIG.

1-8. Condition (A-8)
The preferred range of the ratio (Mz / Mw) of the Z weight average molecular weight (Mz) to the weight average molecular weight (Mw) of the ethylene polymer used in the present invention is 2.0 to 9.0, preferably 2.0 to 2.0. It is 8.0, more preferably 2.5 to 7.0, and particularly preferably 2.5 to 6.0.
If Mz / Mw is less than 2.0, the effect of improving molding processability, particularly melt fluidity and neck-in, will be small and should be avoided. If Mz / Mw is larger than 9.0, the moldability, especially the high-speed moldability, may deteriorate. In the present invention, the Mz of the ethylene polymer or the ethylene / α-olefin copolymer is the above-mentioned gel. It is measured by the permeation chromatography (GPC) method.

1-9. Condition (A-9)
In the ethylene-based polymer used in the present invention, in addition to the above conditions (A-1) to (A-8), the elution amount obtained from the integrated elution curve measured by cross fractionation chromatography (CFC) is further increased. Of the components eluted at a temperature of 50 wt% or less, the proportion of components having a molecular weight of more than the weight average molecular weight (W ₂ ) and the elution amount obtained from the integrated elution curve elute at a temperature higher than the temperature at 50 wt%. The preferred range of the sum (W ₂ + W ₃ ) of the proportions (W ₃ ) of the components whose molecular weight is less than the weight average molecular weight is more than 40% by weight and less than 80% by weight. It is preferably more than 41% by weight, less than 70% by weight, more preferably more than 41% by weight, less than 56% by weight, particularly preferably more than 42% by weight and less than 50% by weight.
When the W ₂ + W ₃ value is 40% by weight or less, the proportion of the low-density high molecular weight component contained in the ethylene polymer that effectively acts to improve the material strength is reduced, and the hot tack property is effectively improved. The high density and low molecular weight components that act may decrease. On the other hand, when the W ₂ + W ₃ value is 80% by weight or more, the balance between the contents of the high-density low molecular weight component and the low-density high molecular weight component contained in the ethylene polymer is lost, and the material strength deteriorates. Or, the dispersibility of the low-density high-molecular-weight component and the high-density low-molecular-weight component may be deteriorated, resulting in the formation of gel.

[Measurement of CFC]
The cross-fractionation chromatograph (CFC) comprises a temperature-increasing elution fractionation (TREF) section for crystalline fractionation and a gel permeation chromatography (GPC) section for molecular weight fractionation.
The analysis using this CFC is performed as follows. First, the polymer sample was completely dissolved in orthodichlorobenzene (ODCB) containing 0.5 mg / mL BHT at 140 ° C., and then the solution was held on a TREF column (inert) at 140 ° C. via the sample loop of the instrument. It is poured into a column packed with a glass bead carrier) and gradually cooled to a predetermined first elution temperature to crystallize the polymer sample. After holding at a predetermined temperature for 30 minutes, the ODCB is passed through a TREF column, so that the eluted component is injected into the GPC section to separate the molecular weight, and the infrared detector (MIRAN, 1A, IR detection manufactured by FOXBORO) is performed. A chromatogram can be obtained by the device, measurement wavelength 3.42 μm). During that time, the temperature is raised to the next elution temperature in the TREF section, a chromatogram of the first elution temperature is obtained, and then the elution component at the second elution temperature is injected into the GPC section. Hereinafter, by repeating the same operation, a chromatogram of the elution component at each elution temperature can be obtained.

The measurement conditions for CFC are as follows.
Equipment: CFC-T102L GPC column manufactured by Dia Instruments: AD-806MS manufactured by Showa Denko (3 connected in series) Solvent: ODCB Sample concentration: 3 mg / mL Injection amount: 0.4 mL Crystallization rate: 1 ° C / min Solvent flow velocity: 1 mL / min GPC measurement time: 34 minutes Stable time after GPC measurement: 5 minutes Elution temperature: 0,5,10,15,20,25,30,35,40,45,49,52,55,58 , 61, 64, 67, 70, 73, 76, 79, 82, 85, 88, 91, 94, 97, 100, 10
2,120,140

(Data analysis)
From the chromatogram of the elution component at each elution temperature obtained by the measurement, the elution amount (proportional to the area of the chromatogram) normalized so that the total sum is 100% can be obtained. Further, an integrated elution curve for the elution temperature as shown in FIG. 5 is calculated. The differential elution curve is obtained by differentiating this integral elution curve with temperature. In addition, the molecular weight distribution can be obtained from each chromatogram by the following procedure. The conversion from the holding capacity to the molecular weight is performed using a calibration curve made of standard polystyrene prepared in advance. The standard polystyrenes used are all the following brands manufactured by Tosoh Corporation. F380, F288, F128, F80, F40, F20, F10, F4, F1, A5000, A2500, A1000.
A calibration curve is created by injecting 0.4 mL of solution dissolved in ODCB (containing 0.5 mg / mL BHT) so that each is 0.5 mg / mL. The calibration curve uses a cubic equation obtained by approximating with the least squares method.
For conversion to molecular weight, a general-purpose calibration curve is used with reference to "Size Exclusion Chromatography" (Kyoritsu Shuppan) by Sadao Mori. At that time, the following numerical values are used for the viscosity formula [η] = K × M ^α to be used.
PS: K = 1.38 × 10 ^-4 , α = 0.7
PE: K = 3.92 × 10 ^-4 , α = 0.733
In the chromatogram at the first elution temperature, the peak due to BHT added to the solvent and the low molecular weight side of the elution component may overlap. In that case, draw a baseline as shown in FIG. 1 to draw a molecular weight distribution. Determine the desired section.
Further, as shown in Table 1 below, the weight average molecular weight of who (whole) is obtained from the elution ratio (wt% in the table) and the weight average molecular weight (Mw in the table) at each elution temperature.

In addition, from the molecular weight distribution and elution amount at each elution temperature, the literature (S. Nakano, Y. Goto, Development of automatic Cross Fractionation: Combination of Crystallizability Fractionation , Pp. 4217-4231 (1981)) to obtain a graph (contour diagram) showing the elution amount with respect to the elution temperature and the molecular weight as contour lines as shown in FIG. The following component amounts are obtained using the above contour diagram.
W ₁ : Percentage of components whose molecular weight is less than the weight average molecular weight among the components eluted at a temperature below the temperature at which the elution amount obtained from the integrated elution curve is 50 wt% W ₂ : The elution amount obtained from the integrated elution curve is 50 wt%. Percentage of components whose molecular weight is equal to or greater than the weight average molecular weight among the components eluted below the temperature W ₃ : The molecular weight of the components eluted at a temperature higher than the temperature at which the elution amount obtained from the integrated elution curve is 50 wt% is less than the weight average molecular weight. Ratio of components W ₄ : Ratio of components whose molecular weight is equal to or greater than the weight average molecular weight among the components eluted at a temperature higher than the temperature at which the elution amount obtained from the integrated elution curve is 50 wt% W ₁ + W ₂ + W ₃ + W ₄ = 100.

1-10. Condition (A-10)
In addition to the above conditions (A-1) to (A-9), the ethylene-based polymer in the present invention further comprises 1-9. The preferred range of the difference between W ₂ and W ₄ (W ₂ -W ₄ ) described above is more than -4% by weight and less than 30% by weight, preferably more than -4% by weight and less than 20% by weight. It is preferably more than -4% by weight and less than 10% by weight.
When W ₂ -W ₄ is -4% by weight or less, the low-density high molecular weight component which acts particularly effectively for improving the material strength contained in the ethylene-based polymer may decrease, which is not preferable. _On the other hand, when the W2 _- W4 value is 30% by weight or more, the balance between the contents of the high-density low molecular weight component and the low-density high molecular weight component is lost, the dispersibility deteriorates, and gel may be generated. It is not preferable because there is.

1-11. Composition of Ethylene-based Polymer Used in the Present Invention The ethylene-based polymer of the present invention is an ethylene homopolymer or a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms, preferably ethylene and 3 carbon atoms. It is a polymer with about 20 α-olefins.
Here, the ethylene homopolymer means a polymer produced by supplying only ethylene as a monomer raw material to a reactor. The α-olefins used here as comonomers include propylene, butene-1, 3-methylbutene-1, 3-methylpentene-1, 4-methylpentene-1, penten-1, hexene-1, and octene. -1, decene-1, tetradecene-1, hexadecene-1, octadecene-1, eikosen-1, and the like can be mentioned. Further, vinyl compounds such as vinylcyclohexane or styrene and its derivatives can also be used. Further, these α-olefins may be used alone or in combination of two or more.
Of these, more preferable α-olefins are those having 3 to 10 carbon atoms such as propylene, butene-1, hexene-1, and octene-1, and more preferable α-olefins are butene-1, hexene-1, and octene. It is -1, and particularly preferably hexene-1.

The ratio of ethylene to α-olefin in the ethylene-based polymer used in the present invention is about 70 to 100% by weight of ethylene, 0 to about 30% by weight of α-olefin, and preferably about 80 to 99.99% by weight of ethylene. , Α-olefins of about 0.01 to 20% by weight, more preferably ethylene of about 80 to 99.9% by weight, α-olefins of about 0.1 to 20% by weight, still more preferably ethylene of about 82 to 99% by weight. .2% by weight, α-olefin about 0.8-18% by weight, particularly preferably ethylene about 85-99% by weight, α-olefin about 1-15% by weight, most preferably ethylene about 88-98%. By weight%, α-olefin is about 2 to 12% by weight. If the ethylene content is within this range, the molding processability is remarkably excellent.

The copolymerization may be any of alternating copolymerization, random copolymerization and block copolymerization. Of course, it is also possible to use a small amount of comonomer other than ethylene or α-olefin. In this case, styrenes such as styrene, 4-methylstyrene and 4-dimethylaminostyrene, 1,4-butadiene, 1,5- It has a polymerizable double bond such as dienes such as hexadiene, 1,4-hexadiene and 1,7-octadien, cyclic compounds such as norbornene and cyclopentene, and oxygen-containing compounds such as hexenol, hexenoic acid and methyl octene. Compounds can be mentioned. However, it goes without saying that when diene is used, the long-chain branched structure must be used within the range satisfying the above condition (4).

2. 2. Method for Producing Ethylene Polymer Used in the Present Invention The ethylene polymer used in the present invention is manufactured and used so as to satisfy all of the above conditions (A-1) to (A-4). The production is carried out by a method of polymerizing ethylene or the like using a catalyst for olefin polymerization.
Various types of catalysts for olefin polymerization are known today, and ethylene-based polymers that satisfy the above conditions can be prepared within the range of the composition of the catalyst component and the device of polymerization conditions and post-treatment conditions. If there is no limitation, the following will be described as an example of a suitable production method for simultaneously realizing the specific long-chain branched structure, composition distribution structure, MFR, and density of the ethylene-based polymer of the present invention. Examples thereof include a method using a catalyst for olefin polymerization containing the specific catalyst components (i), (ii) and (iii).
Component (i): Cross-linked cyclopentadienyl indenyl compound containing a transition metal element Component (ii): A compound that reacts with the compound of component (i) to form a cationic metallocene compound Component (iii): Inorganic compound carrier

2-1. Catalyst component (i)
The preferred catalyst component (i) for producing the ethylene-based polymer used in the present invention is a crosslinked cyclopentadienyl indenyl compound having a five-membered ring structure substituent on the indenyl ring and containing a transition metal element. A metallocene compound represented by the following general formula [1] is more preferable, and a metallocene compound represented by the following general formula [2] is more preferable.
In the present invention, in particular, by using the ligand represented by the formula [2] and further (1-c) as a catalyst component for polymerization, the specific ethylene-based polymer of the present invention can be exclusively and efficiently used. Can be manufactured well. One of the features of the ethylene-based polymer of the present invention is that it is produced by a polymerization method using such a specific polymerization catalyst.

[However, in the formula [1], M represents any transition metal of Ti, Zr or Hf. A ¹ is a ligand having a cyclopentadienyl ring (conjugated five-membered ring) structure, A ² is a ligand having an indenyl ring structure with a five-membered ring structure substituent, and Q ¹ is A ¹ . Shows a binding group that cross-links A ² at any position. X and Y are σ-binding groups, and independently, a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a hydrocarbon group having 1 to 20 carbon atoms including an oxygen atom or a nitrogen atom, and a hydrocarbon group having 1 to 20 carbon atoms. A hydrocarbon group substituted amino group having 1 to 20 carbon atoms or an alkoxy group having 1 to 20 carbon atoms is shown. ]

[However, in the formula [2], M represents any transition metal of Ti, Zr or Hf. ^Q1 indicates a binding group that crosslinks the cyclopentadienyl ring and the indenyl ring. X and Y independently have a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a hydrocarbon group having 1 to 20 carbon atoms including an oxygen atom or a nitrogen atom, and a hydrocarbon having 1 to 20 carbon atoms. A hydrogen-substituted amino group or an alkoxy group having 1 to 20 carbon atoms is shown. Each of the 10 Rs has a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a silicon-containing hydrocarbon group having 1 to 18 carbon atoms including 1 to 6 silicon atoms, and 1 to 18 carbon atoms. It represents 20 halogen-containing hydrocarbon groups, 1 to 20 carbons containing oxygen atoms or 1 to 20 carbons substituted silyl groups, but at least one R on the indenyl ring side. It has a five-membered ring structure. ]

A particularly preferable catalyst component (A) for producing the ethylene-based polymer used in the present invention is a metallocene compound represented by the general formula (1c) described in paragraph 0007 of JP2013-227271A. ..

[However, in the formula (1c), all the explanations of the abbreviations follow the description of Japanese Patent Application Laid-Open No. 2013-227271. That is, M ^1c represents any transition metal of Ti, Zr or Hf. X ^1c and X ^2c independently have a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a hydrocarbon group having 1 to 20 carbon atoms including an oxygen atom or a nitrogen atom, and 1 to 20 carbon atoms. Indicates a hydrocarbon group substituted amino group or an alkoxy group having 1 to 20 carbon atoms. ^Q1c and ^Q2c each independently represent a carbon atom, a silicon atom, or a germanium atom. Each of R ^1c independently represents a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, and at least two of the four R ^1c are bonded to form a ring together with Q ^1c and Q ^2c . May be good. ^mc is 0 or 1, and when ^mc is 0, Q ^1c is directly coupled to a conjugated 5-membered ring containing R ^2c . R ^2c and R ^4c independently have a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a silicon-containing hydrocarbon group having 1 to 18 carbon atoms including 1 to 6 carbon atoms, and 1 carbon atom. It shows a halogen-containing hydrocarbon group of about 20 and a hydrocarbon group having 1 to 20 carbon atoms including an oxygen atom or a hydrocarbon group substituted silyl group having 1 to 20 carbon atoms. R ^3c represents a substituted aryl group represented by the following general (1-ac). ]

[However, in the formula (1-ac), ^Y1c represents an atom of Group 14, Group 15, or Group 16 of the Periodic Table. R ^5c , R ^6c , R ^7c , R ^8c and R ^9c each independently have a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, a hydrocarbon group having 1 to 20 carbon atoms, and a carbon number including oxygen or nitrogen. 1 to 20 hydrocarbon groups, 1 to 20 carbon number substituted amino groups, 1 to 20 carbon number alkoxy groups, 1 to 6 carbon number 1 to 18 carbon number silicon-containing hydrocarbon groups including carbon number 1 to 6, carbon It represents a halogen-containing hydrocarbon group of number 1 to 20 or a hydrocarbon group-substituted silyl group of carbon number 1 to 20, and R ^5c , R ^6c , R ^7c , R ^8c and R ^9c are bonded to each other by adjacent groups. , May form a ring with the atoms attached to them. n ^c is 0 or 1, and when n ^c is 0, the substituent R ^5c does not exist in Y ^1c . p ^c is 0 or 1, and when ^pc is 0, the carbon atom to which R ^7c is bonded and the carbon atom to which R ^9c is bonded are directly bonded. When Y ^1c is a carbon atom, at least one of R ^5c , R ^6c , R ^7c , R ^8c , and R ^9c is not a hydrogen atom. If R ^2c is not a five-membered ring structure substituent, ^pc is 0. ]

Further specific examples of the abbreviations in the above general formula (1c) all follow the description of JP2013-2272171 unless otherwise specified below. The most preferable catalyst component (A) for producing the ethylene / α-olefin copolymer of the present invention is a metallocene compound represented by the general formula (3c) described in paragraph 0013 of JP2013-227271A. Is.
As described above, Japanese Patent Application Laid-Open No. 2013-227271 discloses the catalyst used in the examples of the present invention, but because the specific production conditions and the like are different, Japanese Patent Application Laid-Open No. 2013-227271 Does not disclose the physical properties of the present invention, particularly the polymer having the requirement (4) g'. That is, the present invention is an invention relating to a polymer having novel physical characteristics, which is characterized by manifesting novel and specific physical properties of a polymer achieved by a combination of a specific catalyst and specific production conditions. ..

In the metallocene compound represented by the above general formula (3c), M ^1c , X ^1c , X ^2c , Q ^1c , R ^1c , R ^2c and R ^4c are explanations of the metallocene compound represented by the above general formula (1c). A structure similar to the atom and group shown in 1 can be selected including a preferable embodiment, but R ^2c is most preferably a hydrogen atom and a methyl group, and among the four R ^4c , a carbon atom having a bridging group Q ^1c . The two R ^4c attached to the carbons on both sides of the above are most preferably hydrogen atoms, and the remaining R ^4c are most preferably hydrogen atoms or methyl groups. Further, R ^12c , R ^13c and R ^14c are the same as the atoms and groups of R ^5c , R ^6c , R ^7c , R ^8c and R ^9c shown in the description of the metallocene compound represented by the above general formula (1c). You can choose the structure. And Z ^1c represents an oxygen atom or a sulfur atom.

As a specific example of the above-mentioned metallocene compound, among the compounds listed in Table 1c of JP2013-227271, 55c to 94c and 224c to 303c are preferable, but the compound is not limited thereto.

Further, among the specific compounds exemplified above, more preferable ones are shown below. 55c to 72c, 81c to 86c, 224c to 231c, and the like in the table 1c can be mentioned. Further, a compound in which the zirconium of the above compound is replaced with titanium or hafnium is preferable.

Further, among the specific compounds exemplified above, more preferable ones are shown below. Examples thereof include 55c to 66c, 81c, 82c, 224c to 227c in the table 1c. Further, a compound in which the zirconium of the above compound is replaced with titanium or hafnium is preferable.
The compound of the above specific example is preferably a zirconium compound or a hafnium compound, and more preferably a zirconium compound.

As the catalyst component (i) preferable for producing the ethylene-based polymer used in the present invention, two or more of the above-mentioned crosslinked cyclopentadienyl indenyl compounds can be used, but in that case, the molecular weight distribution and the copolymerization composition It goes without saying that care should be taken not to spread the distribution too much.

2-2. Catalyst component (ii)
The preferred catalyst component (ii) for producing the ethylene-based polymer used in the present invention is a compound that reacts with the compound of the component (i) to produce a cationic metallocene compound, and is a widely used organoaluminum oxy compound. And borane compounds and borate compounds.
More preferably, it is the component (ii) described in JP2013-227271A (0064] to [0083], and more preferably, it is the organoaluminum oxy compound described in the same [0065] to [0069].

2-3. Catalyst component (iii)
Examples of the catalyst component (iii) include commonly used inorganic carriers, particulate polymer carriers, or mixtures thereof. As the inorganic carrier, a metal, a metal oxide, a metal chloride, a metal carbonate, a carbonaceous substance, or a mixture thereof can be used.
The catalyst component (iii) preferable for producing the ethylene-based polymer used in the present invention is an inorganic compound carrier, and more preferably, the inorganic compounds described in JP2013-227271A (Japanese Patent Laid-Open No. 2013-227271] to [0088]. Is. At this time, the metal oxide described in Japanese Patent Application Laid-Open No. [985] is preferable as the inorganic compound.

2-4. Method for Producing a Catalyst for Olefin Polymerization The ethylene-based polymer used in the present invention is suitably produced by a method of polymerizing ethylene using a catalyst for olefin polymerization containing the catalyst components (i) to (iii). The contact method of each component when obtaining the catalyst for olefin polymerization from the catalyst components (i) to (iii) of the present invention is not particularly limited, and for example, the methods (I) to (III) shown below are arbitrary. Can be adopted in.

(I) A catalyst which is a catalyst component (i) which is a crosslinked cyclopentadienylindenyl compound containing the above-mentioned transition metal element and a compound which reacts with the compound of the above-mentioned catalyst component (i) to form a cationic metallocene compound. After contacting with the component (iii), the catalyst component (iii), which is an inorganic compound carrier, is brought into contact with the component (iii).
(II) The catalyst component (i) and the catalyst component (ii) are brought into contact with each other, and then the catalyst component (iii) is brought into contact with the catalyst component (iii).
(III) The catalyst component (ii) and the catalyst component (iii) are brought into contact with each other, and then the catalyst component (i) is brought into contact with the catalyst component (i).

Among these contact methods, (I) and (III) are preferable, and (I) is most preferable. In either contact method, aromatic hydrocarbons such as benzene, toluene, xylene and ethylbenzene (usually 6 to 12 carbon atoms), pentane, heptane, hexane and decane are generally used in an inert atmosphere such as nitrogen or argon. , Dodecane, cyclohexane and other aliphatic or alicyclic hydrocarbons (usually 5 to 12 carbon atoms) and other liquid inert hydrocarbons are used to bring each component into contact with each other under stirring or non-stirring. .. This contact is usually carried out at a temperature of −100 ° C. to 200 ° C., preferably −50 ° C. to 100 ° C., more preferably 0 ° C. to 50 ° C., for 5 minutes to 50 hours, preferably 30 minutes to 24 hours, still more preferably. It is desirable to do it in 30 minutes to 12 hours.

Further, when the catalyst component (i), the catalyst component (ii) and the catalyst component (iii) are brought into contact with each other, as described above, an aromatic hydrocarbon solvent in which a certain component is soluble or sparingly soluble and a certain component are used. Any insoluble or sparingly soluble aliphatic or alicyclic hydrocarbon solvent can be used.

When the contact reaction between the components is carried out stepwise, the solvent used in the previous stage may be used as it is as the solvent for the contact reaction in the subsequent stage without removing the solvent or the like. In addition, after the contact reaction in the previous stage using a soluble solvent, liquid inert hydrocarbons in which certain components are insoluble or sparingly soluble (for example, pentane, hexane, decane, dodecane, cyclohexane, benzene, toluene, xylene, etc.) (Hydrocarbon, alicyclic hydrocarbon or aromatic hydrocarbon) is added to recover the desired product as a solid, or once a part or all of the soluble solvent is removed by means such as drying, which is desired. After the product is taken out as a solid, the subsequent contact reaction of the desired product can also be carried out using any of the above-mentioned inert hydrocarbon solvents. In the present invention, it does not prevent the contact reaction of each component from being carried out a plurality of times.

In the present invention, the ratio of the catalyst component (i), the catalyst component (ii) and the catalyst component (iii) to be used is not particularly limited, but the following range is preferable.
When an organic aluminum oxy compound is used as the catalyst component (ii), the atomic ratio (Al / M) of aluminum of the organic aluminum oxy compound to the transition metal (M) in the catalyst component (i) is usually 1 to 100. The range is preferably 000, preferably 5 to 1,000, more preferably 50 to 500, and particularly preferably 100 to 400, and when a borane compound or a borate compound is used, the transition metal (M) in the catalyst component (i) is used. ), The atomic ratio (B / M) of boron is usually selected in the range of 0.01 to 100, preferably 0.1 to 50, and more preferably 0.2 to 10. Further, when a mixture of an organic aluminum oxy compound, a borane compound and a borate compound is used as the catalyst component (ii), each compound in the mixture is used in the same manner as described above for the transition metal (M). It is desirable to select by ratio.

The amount of the catalyst component (iii) used is 0.0001 to 5 mmol, preferably 0.001 to 0.5 mmol, and more preferably 0.01 to 0.1 mmol per 0.0001 to 5 mmol of the transition metal in the catalyst component (i). It is 1 g per hit.
Further, in the present invention, the ratio of the number of moles of the metal of the catalyst component (ii) to 1 g of the catalyst component (iii) is preferably 0.001 to 0.020 (mol / g), more preferably 0.003. It is ~ 0.012 (mol / g), more preferably 0.004 to 0.010 (mol / g).

The catalyst component (i), the catalyst component (ii) and the catalyst component (iii) are brought into contact with each other by appropriately selecting the above-mentioned contact methods (I) to (III), and then the solvent is removed. A catalyst for olefin polymerization can be obtained as a solid catalyst. The solvent is removed under normal pressure or reduced pressure at 0 to 200 ° C., preferably 20 to 150 ° C., more preferably 20 to 100 ° C. for 1 minute to 100 hours, preferably 10 minutes to 50 hours, still more preferably 30 minutes. It is desirable to do it in ~ 20 hours.

The catalyst for olefin polymerization can also be obtained by the methods (IV) and (V) shown below.
(IV) The catalyst component (i) and the catalyst component (iii) are brought into contact with each other to remove the solvent, and this is used as a solid catalyst component with an organic aluminum oxy compound, a borane compound, a borate compound or a mixture thereof under polymerization conditions. Make contact.
(V) The solvent is removed by contacting the organic aluminum oxy compound, the borane compound, the borate compound or a mixture thereof which are the catalyst component (ii) with the catalyst component (iii), and this is used as a solid catalyst component under polymerization conditions. In contact with the catalyst component (i). Also in the case of the contact method of (IV) and (V), the same conditions as described above can be used as the component ratio, the contact condition and the solvent removal condition.

Further, as a catalyst for olefin polymerization suitable for obtaining the ethylene polymer used in the present invention, a catalyst component (ii) and a catalyst component (iii) that react with the catalyst component (i) to generate a cationic metallocene compound are used. As a component that also serves as a component, a well-known layered silicate described in JP-A No. 05-301917, JP-A-08-127613 and the like can also be used. The layered silicate is a silicate compound having a crystal structure in which planes composed of ionic bonds and the like are stacked in parallel with each other with a weak bonding force. Most layered silicates are naturally produced mainly as the main component of clay minerals, but these layered silicates are not limited to those naturally produced, and may be artificial compounds. These layered silicates may be chemically treated with an acid, an alkali or the like.

Among these, montmorillonite, saponite, byderite, nontronite, saponite, hectorite, stepnsite, bentonite, teniolite and other smectites, vermiculite and mica are preferred.

The ratio of the catalyst component (i) and the layered silicate carrier used is not particularly limited, but the following range is preferable. The amount of the catalyst component (i) supported is 0.0001 to 5 mmol, preferably 0.001 to 0.5 mmol, and more preferably 0.01 to 0.1 mmol per 1 g of the layered silicate carrier.

The catalyst for olefin polymerization thus obtained may be used after prepolymerization of ethylene and / or an appropriate α-olefin monomer, if necessary.

2-5. Polymerization Method of Ethylene Polymer The ethylene polymer used in the present invention preferably has the above 2-4. It is produced by polymerizing ethylene or copolymerizing ethylene with an α-olefin using a catalyst for olefin polymerization prepared by the production method described in 1.

As the α-olefin which is a comonomer, as described in paragraphs 0053 to 0055, α-olefins having 3 to 20 carbon atoms can be used, and two or more kinds of α-olefins can be copolymerized with ethylene. Therefore, it is also possible to use a small amount of a comonomer other than the α-olefin.

In the present invention, the above-mentioned polymerization reaction can be preferably carried out by using a gas phase continuous polymerization apparatus or a slurry continuous polymerization apparatus. The continuous polymerization apparatus refers to a polymerization reaction apparatus having an apparatus capable of continuously supplying raw materials necessary for polymerization such as a catalyst and a monomer and an apparatus capable of continuously discharging a produced polymer. In the case of gas phase continuous polymerization, ethylene or the like is polymerized in a reactor in which a gas stream of ethylene or comonomer is introduced, distributed, or circulated with substantially no oxygen or water. In the case of slurry continuous polymerization, inert hydrocarbons selected from aliphatic hydrocarbons such as isobutane, hexane and heptane, aromatic hydrocarbons such as benzene, toluene and xylene, and alicyclic hydrocarbons such as cyclohexane and methylcyclohexane. In the presence or absence of a hydrogen solvent, ethylene or the like is continuously polymerized. Needless to say, liquid monomers such as liquid ethylene and liquid propylene can also be used as a solvent. In the present invention, a more preferable polymerization is vapor phase continuous polymerization.

The polymerization temperature is usually 0 to 250 ° C., preferably 60 to 110 ° C., more preferably 65 to 95 ° C., and in the case of vapor phase polymerization or slurry polymerization, the flow of the polymer particles produced is not hindered by softening or melting. In the range, by polymerizing at a higher temperature, an ethylene-based polymer having a smaller _GL value can be obtained.
The ethylene partial pressure is usually in the range of normal pressure to 10 MPa, preferably 0.2 to 1.9 MPa, more preferably 0.3 to 1.8 MPa, and particularly preferably 0.4 to 1.6 MPa, and is polymerized. As the time, the average residence time is usually 5 minutes to 20 hours, preferably 1 to 15 hours, and more preferably 3 to 12 hours.

The molecular weight of the produced copolymer can be adjusted to some extent by changing the polymerization conditions such as the type of the catalyst component (i) and the catalyst component (ii), the molar ratio of the catalyst, and the polymerization temperature, but hydrogen is used in the polymerization reaction system. By adding the above, the molecular weight can be adjusted more effectively.

Further, even if a component for the purpose of removing water, a so-called scavenger, is added to the polymerization system, it can be carried out without any problem.
The scavengers include organoaluminum compounds such as trimethylaluminum, triethylaluminum, and triisobutylaluminum, organoaluminum oxy compounds, modified organoaluminum compounds containing branched alkyl, organozinc compounds such as diethylzinc and dibutylzinc, and diethylmagnesium. , Organoaluminium compounds such as dibutylmagnesium and ethylbutylmagnesium, and glinal compounds such as ethylmagnesium chloride and butylmagnesium chloride are used.
Among these, triethylaluminum, triisobutylaluminum, and ethylbutylmagnesium are preferable, and triethylaluminum is particularly preferable.

The long-chain branched structure (that is, g _L , g _m ) and the comonomer copolymer composition distribution (that is, X, Y, W ₁ to W ₄ ) of the produced copolymer are the types of the catalyst component (i) and the catalyst component (ii). It can be adjusted by changing the polymerization conditions such as the molar ratio of the catalyst, the polymerization temperature and pressure, and the time, and the polymerization process.
Even if a catalyst component species that easily forms a long-chain branched structure is selected, it is also possible to produce a polymer having a small number of long-chain branched structures by, for example, lowering the polymerization temperature or increasing the ethylene partial pressure. Even if a catalyst component species having a wide molecular weight distribution or copolymerization composition distribution is selected, a copolymer having a narrow molecular weight distribution or copolymerization composition distribution can be produced by changing, for example, the molar ratio of the catalyst component, the polymerization conditions, and the polymerization process. Be careful as it may occur.

Even in a multi-step polymerization method having two or more stages in which polymerization conditions such as hydrogen concentration, amount of monomer, polymerization pressure, and polymerization temperature are different from each other, the ethylene-based polymer of the present invention can be produced if the polymerization conditions are appropriately set. However, when the ethylene-based polymer used in the present invention is produced by a one-step polymerization reaction, it is preferable because it can be produced more economically without setting complicated polymerization operating conditions.

3. 3. Resin composition for intermediate layer used in the present invention Next, the conditions (B-1) and (B-2) that characterize the resin composition for intermediate layer used in the present invention will be described in detail below for each item.
The resin composition for an intermediate layer used in the present invention is basically characterized by satisfying both the conditions (B-1) and (B-2) described below.
3-1. Condition (B-1)
The melt flow rate (MFR; 190 ° C., under a load of 2.16 kg) of the resin composition for an intermediate layer used in the present invention is 1 g / 10 min to 50 g / 10 min, preferably 1.5 g / 10 min to 40 g / 10. Minutes, more preferably 2.0 g / 10 minutes to 30 g / 10 minutes, still more preferably 2.5 g / 10 minutes to 20 g / 10 minutes.

When the MFR is in this range, the processing characteristics at the time of extrusion laminating are excellent. On the other hand, if the MFR is less than 1 g / 10 minutes, there arises a problem that a load is applied to the machine during extrusion laminating. If the MFR is larger than 50 g / 10 minutes, the neck-in during processing becomes large, which not only deteriorates the yield of the product but also causes smoke and odor, which is not preferable.

1-2. Condition (B-2)
The density of the resin composition for an intermediate layer of the present invention is 0.895 to 0.940 g / cm ³ .
If the density is higher than the above range, the low temperature heat sealing property is inferior. On the other hand, if the density is lower than the above range, it tends to foam when sealed at a high temperature.

[High pressure radical method low density polyethylene]
The resin composition for the intermediate layer contains high pressure radical method low density polyethylene. High-pressure radical method Low-density polyethylene can be obtained by the high-pressure radical method polymerization method. High-pressure radical method Low-density polyethylene has a high melt tension and is particularly used for improving neck-in during extrusion laminating. The physical properties of the high-pressure radical method low-density polyethylene are not particularly specified, but those having an MFR of 1 to 50 g / 10 minutes and a density of 0.915 to 0.930 g / cm3 are preferable. When the MFR and the density are in the above ranges, the balance between neck-in and ductility during processing is improved.

[Content ratio of each component]
The resin composition for an intermediate layer used in the present invention is optionally composed of an ethylene-based polymer satisfying the conditions (A-1) to (A-4) as basic conditions and high-pressure radical method low-density polyethylene within the range of 100% by weight. Although it is adjusted by blending, it is preferable to blend 10 to 99% by weight of the above ethylene-based polymer and 90 to 1% by weight of the high-pressure radical method low-density polyethylene with respect to 100% by weight of the resin composition, more preferably. The above ethylene-based polymer 20 to 99% by weight and the high-pressure radical method low-density polyethylene are blended in an amount of 80 to 1% by weight, and more preferably, the above-mentioned ethylene-based polymer 30 to 99% by weight and the high-pressure radical method low-density polyethylene are 70 to 1% by weight. Mix in% by weight. When the content ratio of each component is within the above range, the balance of sealing properties and processability at low and high temperatures are excellent.
The resin composition for the intermediate layer includes antioxidants, heat-resistant stabilizers, weather-resistant stabilizers, light stabilizers, ultraviolet absorbers, antistatic agents, antifogging agents, and crystals, as long as the effects of the present invention are not significantly impaired. It can contain nucleating agents, neutralizing agents, metal deactivators, colorants, dispersants, slip agents, peroxides, organic or inorganic fillers, optical brighteners, pigments and the like. In addition, the polyethylene resin composition may contain a small amount of resin components other than the ethylene-based polymer and the high-pressure method low-density polyethylene as long as the effects of the present invention are not significantly impaired.

4. Packaging film
The packaging film of the present embodiment is composed of a laminate consisting of at least three layers of a base material layer (I), an intermediate layer (II) and a sealant layer (III), and the resin composition for the intermediate layer is used as the intermediate layer (II). It consists of using things. Further, in this packaging film, preferably, the intermediate layer (II) and the sealant layer (III) are laminated on the base material layer (I) by an extrusion laminating method or a coextrusion laminating method.

Examples of the base material layer (I) include films such as paper, aluminum foil, cellophane, woven fabric, non-woven fabric, and polymer polymer, and examples thereof include high-density polyethylene, medium-density polyethylene, low-density polyethylene, and ethylene / vinyl acetate. Copolymers, ethylene / acrylic acid ester copolymers, olefin polymers such as ionomer, polypropylene, poly-1-butene, poly-4-methylpentene-1, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyacrylate, Vinyl copolymers such as polyacrylonitrile, polyamides such as nylon 6, nylon 66, nylon 7, nylon 10, nylon 11, nylon 12, nylon 610, polymethoxylylen adipamide, polyethylene terephthalate, polyethylene terephthalate / isophthalate, poly. Examples thereof include polyesters such as butylene terephthalate, polyvinyl alcohol, polyethylene / vinyl alcohol copolymers, and films such as polycarbonate. As the film used as the base material layer (I), one type may be used, or two or more types may be used. Further, the film may be stretched depending on the type of the base material. Examples of the stretched film include uniaxial or biaxially stretched polypropylene film, stretched nylon film, stretched polyethien terephthalate film, stretched polystyrene film and the like. Further, a film coated with polyvinylidene chloride, polyvinyl alcohol, or the like, or a film deposited with aluminum, alumina, silica, or a mixture of alumina and silica may be used as the substrate layer (I). In the case of a packaging film for contents containing a liquid or a viscous material, the base material layer (I) is a biaxially stretched nylon film, a biaxially stretched polyethylene terephthalate film, or a film in which silica or alumina is vapor-deposited on the base material. be able to.

The sealant layer (III) is not particularly limited, and a conventionally known ethylenen-based resin composition can be used. For example, an ethylene / α-olefin copolymer or an ethylene / α-olefin copolymer and HPLD can be used. Bunlend composition and the like can be used.
Usually, as a method for producing a laminate, for example, a dry laminating method, a wet laminating method, an extrusion method, a sandwich laminating method, a coextrusion method and the like can be mentioned. For example, examples of the packaging film used for dry lamination or the like include any method such as a calendar method, an air-cooled inflation method, a water-cooled inflation method, and a T-die molding method. The extrusion method includes an extrusion laminating method, a dry laminating method, a sandwich laminating method, a coextrusion laminating method (coextrusion without an adhesive layer, coextrusion with an adhesive layer, coextrusion containing an adhesive resin, etc.). ) Etc.

In the packaging film of the present embodiment, when laminating the sealant layer (III) and the intermediate layer (II) on at least one surface of the base material layer (I), the extrusion laminating method or the coextrusion laminating method is preferably used. Be done. By using these methods, the productivity of the film is excellent. For example, as a method for producing a packaging material for contents containing a liquid, a viscous body, etc., a tandem extrusion laminating method is preferably used from the viewpoint of productivity and quality. The tandem extrusion laminating method is a method of sequentially laminating two types of resin layers. For example, an intermediate layer (II) is laminated on a base material layer (I) as a first layer by an extrusion laminating method, and then two layers are further laminated. This is a method of laminating the sealant layer (III) as an eye.

The laminate constituting the packaging film is not particularly limited in the thickness of the entire laminate, the thickness of each layer, and the thickness ratio of each layer, and can be appropriately selected depending on the contents, applications, and the like. The thickness of the entire laminate is, for example, 40 to 120 μm, the thickness of the base material layer is 10 to 40 μm, and the thickness of the sealant layer is about 10 to 40 μm. When the intermediate layer is provided, the thickness of the intermediate layer can be about 20 to 40 μm. Further, at the time of laminating, in order to improve the adhesiveness of the surface of the base material, surface treatment such as corona discharge treatment, ozone treatment and frame treatment can be performed on the base material layer in advance. Further, in order to enhance the adhesiveness and the like, the anchor coating agent can be applied on the base material in advance and then laminated. Examples of the anchor coating agent include isocyanate-based, polyethyleneimine-based, and polybutadiene-based agents.
The packaging film of the present embodiment can be used as various packaging materials, for example, food packaging materials, medical packaging materials, industrial material packaging materials such as engine oil, and the like. Above all, it can be suitably used as a film for packaging contents containing a liquid. For example, it can be used as a packaging material for containing a liquid containing a solid insoluble matter such as a liquid, a fiber and a powder, and a fluid such as a viscous body as a content.

Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples. The measurement method, evaluation method, and resin material used in Examples and Comparative Examples are as follows.

[Measuring method]
(1) MFR: JIS K6922-2: 1997 Annex (190 ° C, 21.18N load).
(2) Density: Performed in accordance with JIS K6922-2: 1997 Annex (23 ° C.).

[Filling evaluation method]
(1) Liquid filling: Using an automatic liquid filling and packaging machine (manufactured by Taisei Lamick Co., Ltd.), the liquid was filled under the following conditions.
[Filling conditions]
Sealing temperature: (Vertical) 170 ° C, (Horizontal) 125 ° C to 155 ° C Packaging form: Three-way seal Bag dimensions: Width 50 mm x Vertical 100 mm pitch Filling: Water 30 ° C (normal temperature filling) Filling amount: Approximately 15 g Filling speed: 20 m / Minute

(2) Criteria for determining filling suitability Filling was performed by changing the lateral seal temperature under the above conditions, and the presence or absence of bag breakage, seal retreat, and water leakage was evaluated under the following pressure resistance conditions.
[Withstand voltage condition] A withstand voltage tester (manufactured by Komatsu Ltd.) was used to apply a load at 100 kg for 1 minute.
[Evaluation Criteria] ○: The appearance of the horizontal seal was good, there was no bag breakage or water leakage in the pressure resistance evaluation, and no foaming was observed. Δ: The appearance of the horizontal seal was good, but the pressure resistance evaluation showed bag breakage, retreat, and water leakage. X: There was no bag breakage or water leakage in the pressure resistance evaluation, but wrinkles and foaming were observed on the appearance of the horizontal seal.

(3) Evaluation of lateral seal strength after filling The horizontal seal portion of the liquid pouch sample filled under the conditions of (1) was sampled with a width of 15 mm in the filling processing direction, and an angle of 180 ° was used using Orientec's Tencilon. The lateral seal strength of the liquid pouch sample was measured at a speed of 300 mm / min.

[Neck-in evaluation when extruded laminating resin composition for intermediate layer]
When the temperature of the resin extruded from the T-die mounted on the extruder with a diameter of 40 mmφ as an extrusion laminating device is set to 300 ° C., the die width is 400 mm, the die lip opening is 0.8 mm, and the take-up processing speed is 30 m / min. When the extrusion amount was adjusted so that the coating thickness was 20 μm, the difference (unit: mm) between the die width and the width of the obtained coating film was taken as the neck-in. The smaller the neck-in, the wider the effective product width and the better the extrusion laminating workability.

[Evaluation of extrusion load when extrusion laminating of resin composition for intermediate layer]
The temperature of the resin extruded from the T-die mounted on an extruder with a diameter of 40 mmφ equipped with a screw with L / D = 26 and a compression ratio of 4.0 as an extrusion laminating device is set to 300 ° C., and the die width is 400 mm. The extruder motor load (unit: A) when the extrusion amount was adjusted so that the coating thickness became 20 μm when the die lip opening degree was 0.8 mm and the take-up processing speed was 30 m / min was measured. The smaller the motor load, the better the extrusion laminating workability.

[Example]
(1) Synthesis of crosslinked cyclopentadienyl indenyl compound;
Dimethylsilylene (3-methyl-4- (2- (5-methyl) -furyl) -indenyl) (cyclopentadienyl) zirconium dichloride, the method described in JP2013-227271A (0159) to [0165]. Synthesized according to.

(2) Synthesis of catalyst for olefin polymerization;
Under a nitrogen atmosphere, 30 grams of silica baked at 400 ° C. for 5 hours was placed in a 500 ml three-necked flask and dried under reduced pressure for 1 hour with a vacuum pump while heating in an oil bath at 150 ° C. Dimethylsilylene (3-methyl-4- (2- (5-methyl) -furyl) -indenyl) (cyclopentadienyl) zirconium synthesized in (1) above under a nitrogen atmosphere in a separately prepared 200 ml two-necked flask. 369 mg of dichloride was added and dissolved in 80.4 ml of dehydrated toluene, and then at room temperature, a 20% methylaluminoxane / toluene solution 51 manufactured by Albemarle Corporation.
.. 6 ml was added and the mixture was stirred for 30 minutes. While heating and stirring a 500 ml three-necked flask containing vacuum-dried silica in an oil bath at 40 ° C., a total amount of a toluene solution of the reaction product of the zirconocene complex and methylaluminoxane was added. After stirring at 40 ° C. for 1 hour, the toluene solvent was distilled off under reduced pressure while heating at 40 ° C. to obtain a powdery catalyst.

(3) Production of ethylene-based copolymer;
The gas phase continuous copolymerization of ethylene and 1-hexene was carried out using the powdery catalyst obtained in (2) above. That is, a gas phase continuous polymerization apparatus (internal volume 100 L) prepared at a temperature of 75 ° C., a hexene / ethylene molar ratio of 1.76%, a hydrogen / ethylene molar ratio of 1.31%, a nitrogen concentration of 33 mol%, and an ethylene partial pressure of 0.45 MPa. , Fluid bed diameter 10 cm, fluid bed type polymer (dispersant) 1.8 kg), polymerized by keeping the gas composition and temperature constant while intermittently supplying the powdery catalyst at a rate of 0.46 g / hour. went. Further, in order to maintain the cleanliness in the system, 0.03 mol / L of a diluted hexane solution of triethylaluminum (TEA) was supplied to the gas circulation line at 15.7 ml / hr. As a result, the average production rate of the produced polyethylene was 303 g / hour. After producing a cumulative total of 5 kg or more of polyethylene, an ethylene-based copolymer; PE-1 was obtained. The MFR and density of the ethylene-based copolymer (PE-1) were 5.8 g / 10 min and 0.918 g / cm ³ , respectively. Table 2 shows the results of measuring the material properties of PE-1.

(4) Production of resin composition for intermediate layer Antioxidant (Irganox 1076 0.02% by weight, BASF Japan Ltd., BASF Japan Co., Ltd.) with respect to 80% by weight of polyethylene-based copolymer (PE-1). ) Ilgafoss P-EPQ 0.02% by weight) and high-pressure radical method low-density polyethylene (HPLD-1 (MFR: 4.0 g / 10 minutes, density: 0.918 g / cm3)) were added in an amount of 20% by weight. It was pelletized for evaluation by extruding at an extrusion temperature of 180 ° C. using a shaft extruder (USV type 30φ extruder manufactured by Union Plastics).

[Preparation of evaluation film]
Using an extrusion laminating device, a biaxially stretched nylon film (Harden film N2102 manufactured by Toyobo Co., Ltd.) having a width of 300 mm and a thickness of 15 μm is used as a base material layer, and a two-component anchor coating agent (Seikadyne solution manufactured by Dainichiseika) is applied thereto. While coating with a bows roll and blowing ozone at the laminating part, the resin composition for the intermediate layer is melt-extruded and laminated at a take-up speed of 30 m / min and a coating thickness of 20 μm, and the intermediate layer is laminated. did. The extrusion laminating device is set so that the temperature of the resin extruded from the T die mounted on the extruder having a diameter of 40 mmφ is 300 ° C., and the cooling roll surface temperature is 25 ° C., the die width is 400 mm, and the die lip opening is 0.8 mm. The extrusion rate was adjusted so that the coating thickness would be 20 μm when the processing speed was 30 m / min. Further, on this intermediate layer, an ethylene / α-olefin copolymer composition of a sealant layer material (MFR: 8.0 g / 10 minutes, density: 0. 905 g / cm ³ )) was melt-extruded and laminated at an extruded resin temperature of 300 ° C., a take-up speed of 30 m / min, and a coating thickness of 25 μm, and a sealant layer was laminated. The processed laminated film was aged in an oven at 40 ° C. for 48 hours, and then slit to a width of 100 mm to obtain a packaging film for evaluation. Table 3 shows the measurement results of moldability and product physical properties.

[Comparative Example 1]
Ethylene / α-olefin copolymer polymerized using a metallocene catalyst (MFR = 16 g / 10 minutes, density = 0.911 g / cm ³ ethylene / hexene-1 copolymer; PE-2) to 73% by weight On the other hand, antioxidants (Irganox 1076 0.02% by weight manufactured by BASF Japan Co., Ltd., Irgafos P-EPQ 0.02% by weight manufactured by BASF Japan Co., Ltd.) and high-pressure radical low-density polyethylene (HPLD-2 (MFR)). : 1.5 g / 10 minutes, density: 0.919 g / cm ³ )) Using a material blended with 27% by weight for the intermediate layer, a resin composition for the intermediate layer and a packaging film were obtained in the same manner as in Examples. rice field. Table 2 shows the measurement results of the material properties of PE-2. Table 3 shows the evaluation results of the moldability and product physical characteristics of the packaging film.

[Comparative Example 2]
80 weight by weight of an ethylene / α-olefin copolymer (MFR = 9.0 g / 10 minutes, density = 0.918 g / cm ³ ethylene / hexene-1 copolymer; PE-3) polymerized using a metallocene catalyst. %, Antioxidant (Irganox 1076 0.02% by weight manufactured by BASF Japan Co., Ltd., Irgafos P-EPQ 0.02% by weight manufactured by BASF Japan Co., Ltd.) and high-pressure radical method low-density polyethylene (HPLD-1). (MFR: 4.0 g / 10 minutes, density: 0.918 g / cm ³ )) A material blended with 20% by weight was used for the intermediate layer, and the resin composition for the intermediate layer and the packaging film were used in the same manner as in Examples. Got Table 2 shows the measurement results of the material properties of PE-3. Table 3 shows the evaluation results of the moldability and product physical characteristics of the packaging film.

[evaluation]
As shown in Table 3 , the films of the examples had a good appearance at the time of filling, and high-speed liquid filling was possible in a wide temperature range from a low temperature to a high horizontal sealing temperature. Further, although the lateral sealing temperature can be filled from a low temperature, the lateral sealing strength after the liquid filling shows the same sealing strength as in Comparative Examples 1 and 2 when the filling temperature is further higher by 5 ° C.

On the other hand, in Comparative Example 1, as shown in Table 2 , the g _L value, g _m value, Mw / Mn value, and Mz / Mw value of PE-2 are low, and the density of the resin composition for the intermediate layer using PE-2 is low. As shown in Table 3 , not only is the low temperature sealing property inferior to that of the example, but also the extrusion laminating processing property is inferior to that of the example.
Further, in Comparative Example 2, as shown in Table 2 , the g _L value, g _m value, Mw / Mn value, and Mz / Mw value of PE-3 are low, and the MFR of the ethylene resin composition using PE-3 is high. Although the density is higher than that of the examples and the density is the same as that of the examples, not only the sealing temperature range is inferior to that of the examples as shown in Table 3 , but also the extrusion laminating characteristics, especially the extrusion load, are high. Disadvantages were shown.

The present invention produces an extrusion laminate by using an ethylene resin composition containing an ethylene polymer having a specific composition and physical properties as an intermediate layer as a packaging material for a packaging bag for liquids and viscous materials in an automatic filling machine. It is used for various packaging films because it has excellent properties, high heat sealing strength, and high-speed filling in a wide sealing temperature range from low temperature to high temperature. It is especially useful as a liquid packaging bag.

Claims (12)

A resin composition for an intermediate layer used for the intermediate layer (II) of a packaging film having at least a base material layer (I), an intermediate layer (II) and a sealant layer (III), and under the following conditions (A-1). It is an ethylene-based resin composition in which an ethylene-based polymer satisfying (A-4) and high-pressure radical method low-density polyethylene are blended so as to be 100% by weight in total, and the conditions (B-1) and (B-) are A resin composition for an intermediate layer, which is characterized by satisfying 2).
Conditions for ethylene polymer;
(A-1) The melt flow rate (MFR) at 190 ° C. under a 2.16 kg load is 0.1 to 100 g / 10 minutes.
(A-2) The density is 0.895 to 0.940 g / cm ³ .
(A-3) The ratio (Y) of the components eluted at 0 ° C. or lower by the temperature rise elution fraction (TREF) is less than 0.8% by weight.
(A-4) The lowest value (g _L ) between the molecular weights of 100,000 and 1,000,000 in the branch index g'measured by a GPC measuring device combining a differential refractometer, a viscosity detector, and a light scattering detector. Is 0.20 to 0.40.
Conditions for the entire composition;
(B-1) The melt flow rate (MFR) at 190 ° C. under a 2.16 kg load is 1 to 50 g / 10 minutes.
(B-2) The density is 0.895 to 0.940 g / cm ³ . The resin composition for an intermediate layer according to claim 1, wherein the ethylene-based polymer satisfies the following condition (A-5).
(A-5) The value (gm) of the branch index _g'at a molecular weight of 100,000 is 0.50 to 0.75. The resin composition for an intermediate layer according to claim 1 or 2, wherein the ethylene-based polymer satisfies the following condition (A-6).
(A-6) The ratio (X) of the components eluted at 85 ° C. or higher by the temperature rise elution fraction (TREF) exceeds 1% by weight and is less than 70% by weight. The resin composition for an intermediate layer according to any one of claims 1 to 3, wherein the ethylene-based polymer satisfies the following condition (A-7).
(A-7) The molecular weight distribution Mw / Mn measured by gel permeation chromatography (GPC) is 3.0 to 10.0. The resin composition for an intermediate layer according to any one of claims 1 to 4, wherein the ethylene-based polymer satisfies the following condition (A-8).
(A-8) The molecular weight distribution Mz / Mw measured by GPC is 2.0 to 9.0. The resin composition for an intermediate layer according to any one of claims 1 to 5, wherein the ethylene-based polymer satisfies the following condition (A-9).
(A-9) Percentage of components whose molecular weight is equal to or greater than the weight average molecular weight among the components eluted at a temperature or lower at which the elution amount determined from the integrated elution curve measured by cross fractionation chromatography (CFC) is 50 wt% (A-9). W ₂ ) and the sum of the proportions (W ₃ ) of the components whose molecular weight is less than the weight average molecular weight among the components eluted at a temperature higher than the temperature at which the elution amount obtained from the integrated elution curve is 50 wt% (W ₂ + W). ₃ ) is more than 40% by weight and less than 80% by weight. The resin composition for an intermediate layer according to any one of claims 1 to 6, wherein the ethylene-based polymer satisfies the following condition (A-10).
(A-10) Percentage of components whose molecular weight is equal to or higher than the weight average molecular weight among the components eluted at a temperature higher than the temperature at which the elution amount obtained from the integrated elution curve measured by W ₂ and CFC is 50 wt% (W). The difference (W2 _- W4) in ₄ ) is greater than _-4 % by weight and less than 30% by weight. The intermediate according to any one of claims 1 to 7, wherein the ethylene-based polymer is an ethylene homopolymer or a copolymer of ethylene and an α-olefin having 3 to 10 carbon atoms. Resin composition for layers. The packaging film having at least the base material layer (I), the intermediate layer (II) and the sealant layer (III), and the resin composition for the intermediate layer used for the intermediate layer (II), according to claims 1 to 8 . A packaging film using the resin composition for an intermediate layer according to any one of the above. The packaging film according to claim 9, wherein the intermediate layer (II) and the sealant layer (III) are laminated by an extrusion lamination method or a coextrusion lamination method. The packaging film according to claim 10 , wherein the film is for packaging a content containing a liquid. A liquid packaging bag formed in a bag shape using the packaging film according to claim 9 or 10.

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