JP5895483B2 - Ethylene polymer composition for extrusion lamination and laminate - Google Patents

Description

  The present invention relates to an ethylene polymer composition for extrusion laminating and a layer comprising the same, wherein the curl of the laminated molded product is low while the heat resistance is good and the end thickness of the laminated molded product is less likely to be thicker than the central portion. The present invention relates to a laminate having at least one layer.

Among laminates obtained by extrusion lamination, laminates comprising at least one layer of polyethylene resin are used in a wide range of application fields such as craft packaging, flexible packaging, photographic paper supports, tapes, and various containers. Conventionally, the polyethylene resin used in these laminates has been mainly branched low density polyethylene (LDPE) synthesized by radical polymerization because of its excellent moldability. However, the density of LDPE is generally 918 to 925 kg / m ³ , and it is difficult to change physical properties that change with density, such as flexibility, heat resistance, rigidity, gas barrier properties, etc., resulting in limitations in use. It was. On the other hand, linear polyethylene such as linear low density polyethylene (L-LDPE) and linear high density polyethylene (HDPE) can vary widely in density according to the number of short chain branches. Because of poor molding processability, it was difficult to obtain a laminate by extrusion lamination. Therefore, a method of obtaining a laminate by extrusion-laminating a mixture of linear polyethylene and LDPE is often used (for example, see Patent Documents 1 to 4). When heat resistance, rigidity, and gas barrier properties are required, it is desirable to use high-density polyethylene, that is, HDPE as linear polyethylene (see, for example, Patent Documents 5 to 6). The occurrence of curling was a problem. Curling of the laminated body is a phenomenon in which the volume shrinks when the resin solidifies, causing a size difference between the base material and the laminated body warps in one direction. In the next processing, the end of the laminate may get caught in the processing machine or the heat seal part may be turned up, which may cause trouble.

  Since the curl size increases in proportion to the resin density, it is necessary to reduce the resin density in order to suppress the curl, and the compatibility with the heat resistance, rigidity, and gas barrier properties that improve with the resin density is It was difficult.

  In addition, the ethylene polymer composition in which a plurality of resins are mixed has a problem that the end portion of the ethylene polymer composition layer tends to be thicker than the center portion when laminated. When a laminate film is formed by narrowing the width of the ethylene polymer composition layer relative to the base material, the thickness of the ethylene polymer composition layer becomes thicker when the end thickness of the ethylene polymer composition layer is thicker than the center portion. There was a problem that the thick part of the film swelled up and wrinkled into the laminated film, resulting in a significant drop in commercial value. Therefore, an ethylene polymer composition having an end portion having the same thickness as the central portion has been desired.

JP-A-6-65443 JP-A-6-322189 JP-A-7-92610 JP 2000-73018 A JP-A-6-49290 Japanese Patent Laid-Open No. 10-36582

  The present invention has been made in order to solve the above-described problems of the prior art, has good heat resistance, has less curl of the laminate molded product, and has a thickness at the end portion of the laminate molded product. It is an object of the present invention to provide an ethylene polymer composition for extrusion laminating that is less likely to become thicker and a laminate having at least one layer made of the composition.

The present invention has been found as a result of intensive studies on the above-described object. That is, the present invention relates to ethylene having a density of 920 kg / m ³ or more and 955 kg / m ³ or less and a melt flow rate (hereinafter referred to as MFR) of 5 g / 10 min or more and less than 10 g / 10 min and an α-olefin having 3 to 6 carbon atoms. copolymerized comprising ethylene -α- olefin copolymer (a) and 50 to 80 wt%, density 955 kg / ^{m 3} greater than 975 kg / ^{m 3} or less, MFR5g / 10 min or more 40 g / less than 10 minutes of high-density polyethylene (B) 10 to 40 wt% and a density 915 kg / ^{m 3} or more 930 kg / ^{m 3} or less, MFR1.25g / 10 min or more 10 g / 10 minutes or less high-pressure low-density polyethylene (C) consists of 10 to 40 wt% The present invention relates to an ethylene polymer composition for extrusion lamination that satisfies the following requirements (a) to (d).
(A) Melt tension measured at 160 ° C. 10 to 100 mN
(B) MFR4g / 10 min or more 17 g / 10 minutes or less (c) MFR (MFR _A) and high-density polyethylene ethylene -α- olefin copolymer (A) (B) MFR ( MFR B) of the ratio MFR _A / MFR _B is 0.25 to 4.0
(D) the ratio _MFR A / MFR _C of MFR of MFR (MFR _A) and the high-pressure low-density polyethylene ethylene -α- olefin copolymer (A) (C) (MFR C) is 0.25 to 4.0
Hereinafter, the present invention will be described in detail.

  The ethylene-α-olefin copolymer (A) constituting the ethylene-based polymer composition for extrusion lamination of the present invention comprises a repeating unit derived from ethylene and a repeating unit derived from an α-olefin having 3 to 6 carbon atoms. This is an ethylene-α-olefin copolymer. Examples of the α-olefin having 3 to 6 carbon atoms include propylene, 1-butene, 1-hexene, 4-methyl-1-pentene, and 3-methyl-1-butene. You may use together at least 2 types of these C3-C6 alpha olefins.

The ethylene-α-olefin copolymer (A) constituting the ethylene-based polymer composition for extrusion lamination of the present invention has a density measured by the method described in JIS K6760 (1995) of 920 kg / m ³ or more and 955 kg / m ³ or less, preferably 920 kg / ^{m 3} or more 945 kg / ^{m 3} or less, and most preferably is of 920 kg / ^{m 3} or more 935 kg / ^{m 3} or less. Here, when the density is less than 920 kg / m ³ , the heat resistance of the ethylene polymer composition is inferior, which is not preferable. On the other hand, when it exceeds 955 kg / m ³ , the melting temperature of the ethylene-α-olefin copolymer is high, and the ethylene polymer composition is excellent in heat resistance and rigidity, but the composition is used. The curl of the manufactured result layer is undesirably large. The density can be measured by a density gradient tube method in accordance with JIS K6760 (1995).

  The ethylene-α-olefin copolymer (A) constituting the ethylene-based polymer composition for extrusion lamination of the present invention has an MFR measured by the method described in JIS K6760 (1995) of 5 g / 10 min. More than 10 g / 10 minutes, preferably 7 g / 10 minutes or more and less than 10 g / 10 minutes. Here, when MFR is less than 5 g / 10 minutes, the load of the extruder at the time of setting it as an ethylene polymer composition becomes large, and it is not preferable that productivity falls. On the other hand, in the case of 10 g / 10 min or more, there is a possibility that the melt tension is small and the end thickness of the extruded laminate molded product is thicker than the central portion. MFR can be measured with a melt indexer under the conditions of 190 ° C. and a load of 2.16 kg.

The ethylene-α-olefin copolymer (A) constituting the ethylene polymer composition for extrusion lamination of the present invention preferably has a long chain branch in the structure. By having a long chain branch in the structure, the melt tension of the ethylene-α-olefin copolymer (A) is increased, and the laminate processability of the ethylene-based polymer composition for extrusion lamination is improved. In addition, when there are 0.01 to 0.2 long-chain branches having 6 or more carbon atoms per 1000 carbon atoms, neck-in (melting film width drop) and draw-down (upper limit of take-up speed) during lamination processing This is preferable because it has the best balance. In addition, the number of long-chain branches is the number of branches of a hexyl group or more (carbon number of 6 or more) detected by ¹³ C-NMR measurement.

  Furthermore, the ethylene-α-olefin copolymer (A) constituting the ethylene-based polymer composition for extrusion laminating of the present invention is an ethylene polymer or ethylene and carbon having a vinyl group at the terminal obtained by polymerizing ethylene. A macromonomer comprising an ethylene copolymer having a vinyl group at the terminal obtained by copolymerizing an olefin having a number of 3 to 6, and a macromonomer having a number average molecular weight (Mn) of 2000 or more, ethylene or ethylene and A polyethylene polymer obtained by polymerizing an olefin having 3 to 6 carbon atoms is desirable.

  A macromonomer is an olefin polymer having a vinyl group at the end, preferably an ethylene polymer having a vinyl group at the end obtained by polymerizing ethylene, or a copolymer of ethylene and an olefin having 3 to 6 carbon atoms. It is an ethylene copolymer having a vinyl group at the terminal obtained by the process.

  Examples of the olefin having 3 to 6 carbon atoms include propylene, 1-butene, 1-hexene, 4-methyl-1-pentene, 3-methyl-1-butene, α-olefin such as vinylcycloalkane, butadiene or 1,4 -A diene such as hexadiene can be exemplified. Two or more of these olefins can be mixed and used.

  The number average molecular weight (Mn) in terms of linear polyethylene of the macromonomer is preferably 2,000 or more, more preferably 5,000 or more, and more preferably 10,000 or more. The weight average molecular weight (Mw) in terms of linear polyethylene is preferably 4,000 or more, more preferably 10,000 or more, and still more preferably 15,000. By increasing the molecular weight of the macromonomer, the length of the long chain branch introduced into the ethylene-α-olefin copolymer (A) is increased, and the melt tension is improved.

  The ethylene-α-olefin copolymer (A) constituting the ethylene-based polymer composition for extrusion lamination of the present invention has a weight average molecular weight (Mw) to number average molecular weight ratio Mw / Mn in the range of 2 to 5. It is desirable to be. Mw / Mn can be calculated by measuring the weight average molecular weight (Mw) and the number average molecular weight (Mn), which are standard polyethylene equivalent values, by gel permeation chromatography (GPC). When Mw / Mn is in this range, the content ratio of the low molecular weight component in the resin is small, so roll contamination during lamination molding due to leaching of the low molecular weight component, stickiness of the surface of the laminate molded product, heat seal failure, etc. The adverse effect is suppressed, and at the same time, the extrusion load becomes higher than necessary, and the amount of extrusion during lamination is not limited.

  The method for producing the ethylene-α-olefin copolymer (A) is not limited and can be produced by a method using a Ziegler catalyst, a method using a Phillips catalyst, a method using a metallocene catalyst, etc., but a method using a metallocene catalyst It is preferable to manufacture by.

  When producing an ethylene-α-olefin copolymer (A) using a metallocene catalyst, the metallocene catalyst to be used has a metallocene complex, an activation co-catalyst, and, if necessary, an organoaluminum compound as components, A macromonomer is synthesized by a specific metallocene catalyst, and simultaneously with the synthesis of the macromonomer, the copolymerization of the macromonomer and ethylene or the copolymerization of the macromonomer, ethylene and an olefin having 3 to 6 carbon atoms and ethylene and carbon by the specific metallocene catalyst. It is preferable to carry out copolymerization of olefins of 3 to 6.

  Specific metallocene catalysts for synthesizing macromonomers include metallocene complexes, non-bridged bis (indenyl) zirconium complexes, non-bridged bis (cyclopentadienyl) zirconium complexes, bridged bis (cyclopentadienyl) zirconium complexes, Alternatively, a catalyst using a bridged (cyclopentadienyl) (indenyl) zirconium complex (hereinafter referred to as component (j)) is preferable.

  Specific examples of the component (j) include, for example, bis (indenyl) zirconium dichloride, bis (cyclopentadienyl) zirconium dichloride, 1,1,3,3-tetramethyldisiloxane-1,3-diyl-bis (cyclopenta). Dienyl) zirconium dichloride, 1,1-dimethyl-1-silaethane-1,2-diyl-bis (cyclopentadienyl) zirconium dichloride, propane-1,3-diyl-bis (cyclopentadienyl) zirconium dichloride, Dimethylsilanediyl (cyclopentadienyl) (indenyl) zirconium dichloride, dimethylsilanediyl (cyclopentadienyl) (2-methylindenyl) zirconium dichloride, dimethylsilanediyl (cyclopentadienyl) (4,7-dimethyl Ndenyl) zirconium dichloride, dimethylsilanediyl (cyclopentadienyl) (2,4,7-trimethylindenyl) zirconium dichloride and the like, and dimethyl, diethyl, dihydro, diphenyl and dibenzyl of the above transition metal compounds However, it is not limited to these examples.

  In addition, specific metallocene catalysts that perform macromonomer copolymerization at the same time as the synthesis of the macromonomer include a metallocene complex, a bridged (cyclopentadienyl) (fluorenyl) zirconium complex or a bridged (indenyl) (fluorenyl) zirconium complex. A catalyst using (hereinafter referred to as component (k)) is preferred.

  Specific examples of component (k) include, for example, diphenylmethylene (1-cyclopentadienyl) (9-fluorenyl) zirconium dichloride, diphenylmethylene (2-trimethylsilyl-1-cyclopentadienyl) (9-fluorenyl) zirconium dichloride, Diphenylmethylene (1-cyclopentadienyl) (2,7-dimethyl-9-fluorenyl) zirconium dichloride, diphenylmethylene (1-cyclopentadienyl) (2,7-di-t-butyl-9-fluorenyl) zirconium Dichloride, isopropylidene (1-cyclopentadienyl) (9-fluorenyl) zirconium dichloride, isopropylidene (1-cyclopentadienyl) (2,7-di-t-butyl-9-fluorenyl) zirconium dichloride, diphenyl Randiyl (1-cyclopentadienyl) (9-fluorenyl) zirconium dichloride, dimethylsilanediyl (1-cyclopentadienyl) (9-fluorenyl) zirconium dichloride, diphenylmethylene (1-indenyl) (9-fluorenyl) zirconium dichloride Diphenylmethylene (2-phenyl-1-indenyl) (9-fluorenyl) zirconium dichloride, diphenylmethylene (2-phenyl-1-indenyl) (2,7-di-t-butyl-9-fluorenyl) zirconium dichloride, etc. Examples thereof include dimethyl, diethyl, dihydro, diphenyl, and dibenzyl isomers of dichloride and the above transition metal compounds. Moreover, although the compound which substituted the zirconium atom of the said transition metal compound with the titanium atom or the hafnium atom can also be illustrated, it is not limited to these.

  There is no restriction | limiting in particular in the quantity of the component (k) with respect to a component (j), It is preferable that it is 0.0001-100 times mole, Most preferably, it is 0.001-10 times mole.

  The activation co-catalyst used as a component of the metallocene catalyst is a metallocene complex or a compound that plays a role in converting a reaction product of a metallocene complex and an organoaluminum compound into an active species capable of olefin polymerization. It is preferable that it is a compound which produces | generates a reactive compound, and the produced | generated cationic compound acts as a polymerization active seed | species which can superpose | polymerize an olefin. An activation co-catalyst is a compound that provides a compound that, after forming a polymerization active species, coordinates weakly or interacts with the generated cationic compound, but does not react directly with the active species.

  Specific examples of the activation promoter include alkylaluminoxanes such as methylaluminoxane, silica gel-supported alkylaluminoxanes, tris (fluorinated aryl) borons such as tris (pentafluoreophenyl) boron, N, N-dimethylammonium-tetrakis ( Examples thereof include boron compounds such as tetrakis (fluorinated aryl) boron salts such as pentafluorophenyl) boron, silica gel-supported materials thereof, clay minerals, clay minerals treated with organic compounds, and the like. Among these, it is preferable to use a clay mineral treated with an organic compound.

  When a clay mineral treated with an organic compound is used as the activation promoter, the clay mineral used is preferably a clay mineral belonging to the smectite group, and specific examples include montmorillonite, beidellite, saponite, hectorite and the like. It is also possible to use a mixture of a plurality of these clay minerals.

  The organic compound treatment means introducing an organic ion between clay mineral layers to form an ionic complex.

  Examples of the organic compound used in the organic compound treatment include N, N-dimethyl-n-octadecylamine hydrochloride, N, N-dimethyl-n-eicosylamine hydrochloride, N, N-dimethyl-n-docosylamine hydrochloride, N, N-dimethyloleylamine hydrochloride, N, N-dimethylbehenylamine hydrochloride, N-methyl-bis (n-octadecyl) amine hydrochloride, N-methyl-bis (n-eicosyl) amine hydrochloride, N-methyl -Alkylammonium salts such as dioleylamine hydrochloride, N-methyl-dibehenylamine hydrochloride, N, N-dimethylaniline hydrochloride can be exemplified.

  The metallocene catalyst is a method of reacting a mixture of component (j) and component (k) with an activation promoter, a method of reacting component (j) and the activation promoter, and then reacting component (k), Although it prepares by the method of making (j) and component (k) react separately, there is no restriction | limiting in particular in the preparation method of a metallocene catalyst.

  As the metallocene catalyst, an alkylaluminum such as triethylaluminum or triisobutylaluminum may be used as necessary for the activation of the metallocene complex and the removal of impurities in the solvent during the preparation of the catalyst.

  When producing the ethylene-α-olefin copolymer (A) which is a component of the polyethylene resin composition for extrusion lamination of the present invention, it is preferable to carry out at a polymerization temperature of −100 to 120 ° C., especially considering productivity. It is preferably 20 to 120 ° C, more preferably 60 to 120 ° C. The polymerization time is preferably in the range of 10 seconds to 20 hours, and the polymerization pressure is preferably in the range of normal pressure to 300 MPa. The polymerizable monomer is ethylene alone or ethylene and an α-olefin having 3 to 6 carbon atoms. When ethylene is an α-olefin having 3 to 6 carbon atoms, ethylene and α-olefin having 3 to 6 carbon atoms are used. As the olefin supply ratio, ethylene / C3-C6 α-olefin (molar ratio) of 1 to 200, preferably 3 to 100, and more preferably 5 to 50 can be used. It is also possible to adjust the molecular weight using hydrogen during polymerization. The polymerization can be carried out by any of batch, semi-continuous and continuous methods, and can be carried out in two or more stages by changing the polymerization conditions. In addition, the ethylene copolymer can be obtained by separating and recovering from the polymerization solvent by a conventionally known method after the completion of the polymerization and drying.

  Polymerization can be carried out in a slurry state, a solution state, or a gas phase state. In particular, when the polymerization is performed in a slurry state, an ethylene-based copolymer having a powder particle shape is efficiently and stably produced. Can do.

  The number of long chain branches of the ethylene-α-olefin copolymer (A) that is a component of the polyethylene resin composition for extrusion lamination of the present invention can be increased by increasing the number of terminal vinyls of the macromonomer. The number of terminal vinyls of the macromonomer can be controlled by selecting a metallocene compound for synthesizing the macromonomer. For example, it can be increased by changing the non-bridged metallocene compound to a bridged metallocene compound.

  Mw / Mn of the ethylene-α-olefin copolymer (A) which is a component of the polyethylene resin composition for extrusion lamination of the present invention can be increased by decreasing Mn of the macromonomer. The Mn of the macromonomer can be controlled by selecting a metallocene compound for synthesizing the macromonomer. For example, it can be reduced by changing a non-bridged metallocene compound to a bridged metallocene compound.

  The high-density polyethylene (B) constituting the ethylene polymer composition of the present invention is an ethylene homopolymer and / or an ethylene-α-olefin copolymer polymerized by a Ziegler catalyst, a Phillips catalyst, a metallocene catalyst, or the like. . Examples of the α-olefin include propylene, 1-butene, 1-hexene, 1-octene, 4-methyl-1-pentene, 3-methyl-1-butene and vinylcycloalkane.

High-density polyethylene constituting the ethylene polymer composition (B) of the present invention, JIS K6760 (1995) Density measured by the method of 955 kg / ^{m 3} greater than 975 kg / ^{m 3} or less, preferably a density of 955 kg / m ³ is intended greater than the 970 kg / ^{m 3} or less. A density of 955 kg / m ³ or less is not preferable because the heat resistance of the ethylene polymer composition of the present invention decreases. On the other hand, when the density is greater than 975 kg / m ³ , the curl of the laminate formed by molding the ethylene polymer composition of the present invention becomes very large, which is not preferable.

  The high density polyethylene (B) constituting the ethylene polymer composition of the present invention has an MFR measured by the method of JIS K6760 (1995) of 5 g / 10 min or more and less than 40 g / 10 min, preferably 15 g / 10 min or more. It is less than 40 g / 10 minutes. Here, when the MFR is less than 5 g / 10 min, the extrusion load at the time of laminating the ethylene polymer composition is increased, which is not preferable. On the other hand, in the case of 40 g / 10 min or more, the melt tension becomes small, and there is a possibility that the end thickness of the extruded laminate molded product becomes thicker than the central portion.

  The high-pressure method low-density polyethylene (C) constituting the ethylene-based polymer composition for extrusion lamination of the present invention can be obtained by a conventionally known high-pressure radical polymerization method, and is appropriately selected within the scope of the present invention.

High-pressure low-density polyethylene constituting the ethylene polymer composition of the present invention (C) is, JIS K6760 (1995) Density measured by the method of 915 kg / ^{m 3} or more 930 kg / ^{m 3} or less, preferably 915 kg / m ³ or more and 925 kg / m ³ or less. When the density is less than 915 kg / m ³ , the heat resistance of the ethylene polymer composition of the present invention may be lowered. On the other hand, when the density is higher than 930 kg / m ³ , the high-temperature low-density polyethylene has a high melting temperature, and the ethylene polymer composition has excellent heat resistance and rigidity, but has poor laminate processability.

  The high pressure low density polyethylene (C) constituting the ethylene polymer composition of the present invention has an MFR measured by the method of JIS K6760 (1995) of 1.25 g / 10 min to 10 g / 10 min, preferably 2 .5 g / 10 min or more and 5 g / 10 min or less. Here, when the MFR is less than 1.25 g / 10 minutes, the extrusion load at the time of laminating the ethylene-based polymer composition is increased, which is not preferable. On the other hand, if it exceeds 10 g / 10 minutes, the melt tension becomes small and the neck-in at the time of lamination increases, which is not preferable.

  An ethylene-based polymer composition for extrusion laminating a specific amount of an ethylene-α-olefin copolymer (A), high-density polyethylene (B) and high-pressure low-density polyethylene (C) satisfying the above requirements is obtained by extrusion laminating. It has excellent heat resistance and curl balance when made into a laminate. The ethylene-based polymer composition of the present invention has an ethylene-α-olefin copolymer (A) of 50 to 80% by weight, preferably 50 to 70% by weight, and high density polyethylene (B) of 10 to 40% by weight, preferably It is composed of 10 to 30% by weight, and 10 to 40% by weight, preferably 20 to 35% by weight of high-pressure low-density polyethylene (C). If the blending amount of the high density polyethylene (B) is less than 10% by weight, the density of the ethylene polymer composition is lowered and the heat resistance is lowered, which is not preferable. On the other hand, if the blending amount exceeds 40% by weight, While the density of the combined composition is increased and the heat resistance and rigidity are improved, curling of the laminate is increased, which is not preferable. On the other hand, when the blending amount of the high-pressure method low density polyethylene (C) is less than 10% by weight, the melt tension of the ethylene polymer composition becomes small, and the neck-in at the time of laminating increases, which is not preferable. When the amount is more than% by weight, the density of the ethylene-based polymer composition becomes low and the heat resistance becomes poor, which is not preferable.

  The ethylene polymer composition for extrusion lamination of the present invention has a melt tension measured at 160 ° C. of 10 to 100 mN, preferably 20 to 100 mN. When the melt tension is less than 10 mN, the neck-in at the time of laminating becomes large, which is not preferable. On the other hand, if the melt tension exceeds 100 mN, the high-speed spreadability during lamination may be inferior, which is not preferable.

  The ethylene polymer composition for extrusion lamination of the present invention has an MFR measured by the method of JIS 6760 (1995) of 4 g / 10 min to 17 g / 10 min, preferably 7 g / 10 min to 17 g / 10 min. More preferably, it is 10 g / 10 min or more and 17 g / 10 min or less. When the MFR is less than 4 g / 10 minutes, the high-speed spreadability at the time of lamination may be inferior, which is not preferable. On the other hand, when the MFR exceeds 17 g / 10 min, the end thickness of the extrusion-laminated molded product may be thicker than the center portion, which is not preferable.

Extrusion laminating the ethylene-based polymer composition of the present invention, the ratio _MFR A / MFR of the MFR of the ethylene -α- olefin copolymer _(A) MFR (MFR A) and high-density polyethylene _(B) (MFR B) _B is 0.25 to 4.0, and ethylene -α- olefin copolymer _(a) MFR (MFR a) and MFR of the high-pressure low-density polyethylene _(C) (MFR C) the ratio _MFR a / The MFR _C is 0.25 to 4.0. When each MFR of ethylene-α-olefin copolymer (A), high-density polyethylene (B), and high-pressure method low-density polyethylene (C) does not satisfy these relationships, the viscosity difference at the time of melting of each constituent component is Since it becomes large and uniform mixing becomes difficult, unevenness in the fluidity of the ethylene-based polymer composition occurs at the time of laminating, and the end thickness of the extruded laminate molded product may be thicker than the central portion, which is preferable Absent.

  In the ethylene polymer composition of the present invention, a stabilizer, a lubricant, a flame retardant, a dispersant, a filler, a foaming agent, a foaming nucleating agent, and a crosslinking agent are included in the range not departing from the gist of the present invention. , UV inhibitors, antioxidants, colorants, and the like can be included. Moreover, it can also be used by mixing with other thermoplastic resins.

  For the ethylene polymer composition of the present invention, a method for forming a resin composition usually can be used. For example, as a melting / mixing method, extrusion kneading using a single screw extruder or a twin screw extruder, roll kneading. And the like, and can be obtained by melt-kneading by this method.

  The ethylene polymer composition of the present invention may be formed into a laminate by directly bonding a molten film made of an ethylene polymer composition extruded from a T die to a substrate by a known extrusion laminating machine. And having at least one layer made of the ethylene polymer composition of the present invention.

The laminate of the present invention preferably satisfies the following requirement (g).
(G) a maximum value d _H and the minimum value d _L thickness of consisting ethylene polymer composition layer satisfies the relation of equation (1).

(D _H −d _L ) / d _L ≦ 0.15 (1)
If the maximum value d _H and the minimum value d _L thickness of consisting ethylene polymer composition layer satisfies the relationship of formula (1), when the laminate of the present invention is to scroll, swellings thick portion of the thick There is no problem that the laminate film is wrinkled and the commercial value is greatly reduced, which is preferable.

The extrusion laminate molding method may be any of single laminate, tandem laminate, coextrusion laminate, and sandwich laminate, and is not particularly limited. Moreover, when performing an extrusion laminating process, it is preferable to extrude from a die at a temperature of 250 to 350 ° C. in order to obtain a laminate having good adhesion between the substrate and the ethylene polymer composition layer. Further, at least the surface where the molten film of the ethylene polymer composition is in contact with the substrate may be oxidized with air or ozone gas. When the oxidation reaction with air proceeds, it is preferable to extrude from a die at a temperature of 270 ° C. or higher, and when the oxidation reaction with ozone gas proceeds, it is preferable to extrude at 250 ° C. or higher. In addition, it is preferable that the processing amount of ozone gas is 0.5 mg or more per 1 m ^{2 of} the film extruded from the die. Moreover, in order to improve adhesiveness with a base material, you may perform well-known surface treatments, such as an anchor-coat agent process, a corona discharge process, a flame process, and a plasma process, to the adhesion surface of a base material.

  Examples of the substrate include synthetic polymer film and sheet, woven fabric, non-woven fabric, metal foil, paper, cellophane and the like. Examples thereof include films and sheets made of a synthetic polymer such as polyethylene terephthalate, polyamide, polyvinyl alcohol, polycarbonate, polyethylene, and polypropylene. Further, these polymer films and sheets may be further subjected to aluminum vapor deposition, alumina vapor deposition, or silicon dioxide vapor deposition. Further, these polymer films and sheets may be further printed using urethane-based ink or the like. Examples of the metal foil include aluminum foil and copper foil, and examples of the paper include kraft paper, stretched paper, high-quality paper, glassine paper, board paper such as cup base paper and photographic paper base paper.

  Laminates of the present invention are dried foods such as snacks and instant noodles, soups, miso, pickles, sauces, aquatic food and beverage packaging such as beverages, pharmaceutical packaging such as medicines and infusion bags, shampoos, cosmetics, diaper back sheets To be used as a wide range of films, containers, tapes, supports, such as toiletries, photographic paper supports, paper containers and lids, paper plates, release papers and release tapes, easy-release films, paper semi-retort packs, etc. Can do.

  The ethylene-based polymer composition for extrusion laminating of the present invention has good heat resistance, but has little curling of the laminate molded product, and can be used as a film, container, tape, and support for a wide range of applications. It is extremely useful as a material.

  Hereinafter, although an example and a comparative example explain the present invention, the present invention is not limited to these.

-Measurement of molecular weight and molecular weight distribution-
The weight average molecular weight (Mw), number average molecular weight (Mn), and ratio of the weight average molecular weight to the number average molecular weight (Mw / Mn) of the macromonomer and the ethylene-α-olefin copolymer (A) are gel permeation Measured by chromatography (GPC). Tosoh Co., Ltd. HLC-8121GPC / HT is used as the GPC apparatus, Tosoh Co., Ltd. TSKgel GMHhr-H (20) HT is used as the column, the column temperature is set to 140 ° C., and 1 is used as the eluent. Measurement was performed using 2,4-trichlorobenzene. A measurement sample was prepared at a concentration of 1.0 mg / ml, and 0.3 ml was injected and measured. The calibration curve of molecular weight is calibrated using a polystyrene sample having a known molecular weight. In addition, Mw and Mn were calculated | required as a value of linear polyethylene conversion.

~ Measurement of density ~
The density of the ethylene-α-olefin copolymer (A) and the ethylene polymer composition was measured by a density gradient tube method in accordance with JIS K6760 (1995).

~ Measurement of MFR ~
The MFR of the ethylene-α-olefin copolymer (A) and the ethylene polymer composition was measured with a melt indexer in accordance with JIS K6760 (1995).

~ Measurement of melt tension ~
The melt tension of the ethylene-based polymer composition is a die having a length of 8 mm, a diameter of 2.095 mm, and an inflow angle of 90 ° on a capillary viscometer (Toyo Seiki Seisakusho, trade name: Capillograph) with a barrel diameter of 9.55 mm. Was measured. For the melt tension, the temperature was set to 160 ° C., the piston lowering speed was set to 10 mm / min, the stretch ratio was set to 47, and the load (mN) required for take-up was measured. When the maximum draw ratio was less than 47, the load (mN) required for taking-up at the highest draw ratio that did not break was taken as the melt tension.

-Measurement of the number of long chain branches-
The number of long chain branches of the ethylene-α-olefin copolymer (A) was measured by 13C-NMR using a Varian VNMRS-400 nuclear magnetic resonance apparatus by 13C-NMR. The solvent is tetrachloroethane-d2. The number per 1,000 main chain methylene carbons was determined from the following formula (4) described in “Macromolecules” Vol. 31, No. 25, pages 8679-8683 (1998).

Number of long chain branches = IAα / (3 × IAtot) (4)
[Wherein, IAα is the integrated intensity of a long-chain branched α-carbon peak (chemical shift: 34.6 ppm) above the hexyl group, and IAtot is the integrated intensity of the main chain methylene carbon peak (30.0 ppm). . ]
~ Neck-in ~
The ethylene polymer composition was supplied to an extruder of an extrusion laminator (manufactured by Musashinokikai Co., Ltd.) having a 90 mmφ screw, extruded from a T die having an opening width of 600 mm at a temperature of 315 ° C., and a substrate take-up speed of 200 m / T-die opening width and ethylene when the extrusion laminating resin composition is extruded on a kraft paper substrate having a width of 600 mm and a basis weight of 50 g / m ² so that the thickness of the central portion is 20 μm. The difference from the coating width of the polymer composition was defined as neck-in, and the value was measured.

~curl~
The laminate produced in the measurement of ~ neck-in ~ was placed on a flat surface with the ethylene polymer composition layer facing upward, and a 10 cm square was drawn on this. A cut was made in the diagonal line of the square, and after standing for 24 hours under conditions of an air temperature of 23 ° C. and a relative humidity of 50%, the height at which the cut portion was warped from the flat surface was measured.

-Heat resistance (gross change)-
~ Neck-in ~ The laminate produced in the measurement of the neck is heated for 30 seconds at a temperature of 110 to 135 ° C (at intervals of 5 ° C) using a small oven (manufactured by Werner Mathis), and an ethylene polymer composition before and after heating. The gloss on the layer side was measured with a gloss meter (manufactured by Nippon Denshoku). The temperature at which the gloss value after heating exceeded 120% of the gloss value before heating was defined as the heat resistant temperature.

-Thickness change of ethylene polymer composition layer-
The thickness of the laminate produced in the measurement of ~ neck-in was measured every 50 mm from the end, and the thickness of the thickest part was d _H (mm) and the thickness of the thinnest part was d _L (mm).

Synthesis example 1
[Preparation of modified hectorite]
After adding 3 liters of ethanol and 100 ml of 37% concentrated hydrochloric acid to 3 liters of water, 585 g (1.1 mol) of N-methyl-dioleylamine was added to the resulting solution and heated to 60 ° C. to form the hydrochloride salt. A solution was prepared. 1 kg of hectorite was added to this solution. The suspension was stirred at 60 ° C. for 3 hours, the supernatant was removed, and then washed with 50 L of 60 ° C. water. Then, it dried at 60 degreeC and 10 < ^-3 > torr for 24 hours, and the modified | denatured hectorite with an average particle diameter of 5.2 micrometers was obtained by grind | pulverizing with a jet mill.
[Preparation of polyethylene resin production catalyst]
500 g of the modified hectorite was suspended in 1.7 liters of hexane, dimethylsilanediyl (cyclopentadienyl) (2,4,7-trimethylindenyl) zirconium dichloride, 8.81 g (20.0 mmol), and triisobutylaluminum. Hexane solution (0.714M) of 2.8 liters (2 mol) was added, and the mixture was stirred at 60 ° C. for 3 hours, then allowed to stand to remove the supernatant, and further triisobutylaluminum hexane solution (0. 15M) was added to obtain a macromonomer synthesis catalyst (100 g / L).

The macromonomer synthesis catalyst prepared above was mixed with 5 mol% of diphenylmethylene (1-cyclopentadienyl) (9- 9%) based on dimethylsilanediyl (cyclopentadienyl) (2,4,7-trimethylindenyl) zirconium dichloride. Fluorenyl) zirconium dichloride (0.58 g, 1.05 mmol) was added and stirred at room temperature for 6 hours. The supernatant was removed by standing, and a hexane solution (0.15 M) of triisobutylaluminum was added to finally obtain a 100 g / L polyethylene resin production catalyst.
[Production of ethylene-α-olefin copolymer (A-1)]
In the polymerization vessel having an internal volume of 540 L, the above-mentioned [145 kg / hour of hexane, 33.0 kg / hour of ethylene, 5.3 kg / hour of butene-1, 4 NL / hour of hydrogen and 30 kg / hour of polymer production] The polyethylene resin production catalyst prepared in [Preparation of polyethylene resin production catalyst] was continuously supplied, and the polymerization reaction was continuously carried out while maintaining the total pressure at 3,000 kPa and the polymerization vessel internal temperature at 60 ° C. The slurry was continuously extracted from the polymerization vessel to remove unreacted hydrogen, ethylene, and butene-1, and then separated and dried to obtain an ethylene-α-olefin copolymer (A-1) powder. This was melt-kneaded using a 50 mm diameter single screw extruder set at 200 ° C. and pelletized to obtain ethylene-α-olefin copolymer (A-1) pellets. The density of the obtained ethylene-α-olefin copolymer (A-1) pellets was 921 kg / m ³ , MFR was 9.0 g / 10 min, the number of long-chain branches was 0.13 per 1000 carbon atoms, and the weight average The ratio Mw / Mn between the molecular weight (Mw) and the number average molecular weight (Mn) was 3.8.

  In this synthesis example, ethylene and 1-butene are polymerized simultaneously with the production of the macromonomer shown in Reference Example 1 below.

Reference example 1
[Synthesis of macromonomer]
In Synthesis Example 1 [Production of ethylene-α-olefin copolymer (A-1)], the macromonomer synthesis catalyst prepared in Synthesis Example 1 [Preparation of polyethylene resin production catalyst] was used instead of the polyethylene resin production catalyst. Except having used, it carried out similarly to the synthesis example 1, and obtained the macromonomer pellet. Mn of the obtained macromonomer pellet was 20,000, and Mw / Mn was 2.8. Further, when the terminal structure of the macromonomer pellet was analyzed, the number of terminal vinyls per 1,000 carbons was 0.05.

Synthesis example 2
[Production of ethylene-α-olefin copolymer (A-2)]
In Synthesis Example 1 [Production of ethylene-α-olefin copolymer (A-1)], butene-1 was changed from 5.3 kg / hour to 5.0 kg / hour, and the hydrogen supply amount was changed from 4 NL / hour to 2 NL / hour. The same procedure as in Synthesis Example 1 was carried out to obtain an ethylene-α-olefin copolymer (A-2). The density of the obtained ethylene-α-olefin copolymer (A-2) is 921 kg / m ³ , MFR is 6.0 g / 10 min, the number of long-chain branches is 0.10 per 1000 carbon atoms, and the weight average molecular weight The ratio Mw / Mn between (Mw) and the number average molecular weight (Mn) was 4.2.

Reference example 2
[Synthesis of macromonomer]
In Synthesis Example 2 [Production of ethylene-α-olefin copolymer (A-2)], the macromonomer synthesis catalyst prepared in Synthesis Example 1 [Preparation of polyethylene resin production catalyst] was used instead of the polyethylene resin production catalyst. A macromonomer pellet was obtained in the same manner as in Synthesis Example 2 except that it was used. Mn of the obtained macromonomer pellet was 21,000, and Mw / Mn was 2.7. Further, when the terminal structure of the macromonomer pellet was analyzed, the number of terminal vinyls per 1,000 carbons was 0.05.

Synthesis example 3
[Production of ethylene-α-olefin copolymer (A-3)]
In Synthesis Example 1 [Production of ethylene-α-olefin copolymer (A-1)], butene-1 was changed from 5.3 kg / hour to 0.5 kg / hour, the polymerization temperature was changed from 60 ° C. to 85 ° C. Was carried out in the same manner as in Synthesis Example 1 except that the polyethylene-based resin production catalyst prepared in Synthesis Example 3 [Preparation of polyethylene-based resin production catalyst] was used, and an ethylene-α-olefin copolymer (A-3) was obtained. Obtained. The resulting ethylene-α-olefin copolymer (A-4) has a density of 954 kg / m ³ , MFR of 9.0 g / 10 min, a long-chain branch number of 0.03 per 1000 carbon atoms, and a weight average molecular weight. The ratio Mw / Mn between (Mw) and the number average molecular weight (Mn) was 2.3.

Reference example 3
[Synthesis of macromonomer]
In Synthesis Example 3 [Production of ethylene-α-olefin copolymer (A-3)], the macromonomer synthesis catalyst prepared in Synthesis Example 3 [Preparation of polyethylene resin production catalyst] was used instead of the polyethylene resin production catalyst. A macromonomer pellet was obtained in the same manner as in Synthesis Example 3 except that it was used. Mn of the obtained macromonomer pellet was 17,000, and Mw / Mn was 2.3. Further, when the terminal structure of the macromonomer pellet was analyzed, the number of terminal vinyls per 1,000 carbons was 0.02.

Synthesis example 4
[Production of ethylene-α-olefin copolymer (A-4)]
In Synthesis Example 1 [Production of ethylene-α-olefin copolymer (A-1)], the hydrogen supply amount was changed from 4 NL / hour to 5 NL / hour, and the same procedure as in Synthesis Example 1 was carried out. The union (A-4) was obtained. The density of the obtained ethylene-α-olefin copolymer (A-4) is 920 kg / m ³ , MFR is 12.7 g / 10 min, the number of long-chain branches is 0.10 per 1000 carbon atoms, and the weight average molecular weight The ratio Mw / Mn between (Mw) and the number average molecular weight (Mn) was 4.2.
Reference example 4
[Synthesis of macromonomer]
In Synthesis Example 4 [Production of ethylene-α-olefin copolymer (A-4)], the macromonomer synthesis catalyst prepared in Synthesis Example 4 [Preparation of polyethylene resin production catalyst] was used instead of the polyethylene resin production catalyst. Except having used, it carried out similarly to the synthesis example 4, and obtained the macromonomer pellet. Mn of the obtained macromonomer pellet was 20,000, and Mw / Mn was 2.8. Further, when the terminal structure of the macromonomer pellet was analyzed, the number of terminal vinyls per 1,000 carbons was 0.05.

下記実施例および比較例で用いた高密度ポリエチレンおよび高圧法低密度ポリエチレンの特性を表２に示す。

Table 2 shows the characteristics of the high-density polyethylene and high-pressure method low-density polyethylene used in the following Examples and Comparative Examples.

実施例１
合成例１に示したエチレン−α−オレフィン共重合体（Ａ−１）６５重量％、高密度ポリエチレン（東ソー（株）製 商品名ニポロンハード １０００；密度９６６ｋｇ／ｍ^３、ＭＦＲ２０．１ｇ／１０分）（以下、（Ｂ−１）という。）１５重量％、高圧ラジカル重合法で得られた低密度ポリエチレン（東ソー（株）製 商品名ペトロセン ２０５；密度９２４ｋｇ／ｍ^３、ＭＦＲ３．０ｇ／１０分）（以下、（Ｃ−１）という。）２０重量％、をタンブラーミキサーにて予備混合した後、シリンダー温度１８０℃に調整した単軸押出機（（株）プラコー製、型式 ＰＤＡ−５０）で溶融混練、造粒し、エチレン系重合体組成物のペレットを得た。得られたペレットは、エチレン系重合体組成物の評価方法に示した方法によりラミネート成形した。 得られたエチレン系重合体組成物により密度、ＭＦＲ、溶融張力、および融点を測定し、押出ラミネート成形時にネックインとカールおよびエチレン系重合体組成物層の厚みの評価を行った。これらの評価結果を表３に示す。

Example 1
65% by weight of ethylene-α-olefin copolymer (A-1) shown in Synthesis Example 1, high-density polyethylene (trade name Nipolon Hard 1000 manufactured by Tosoh Corporation; density 966 kg / m ³ , MFR 20.1 g / 10 min) (Hereinafter referred to as (B-1)) 15% by weight, low density polyethylene obtained by high-pressure radical polymerization method (trade name Petrocene 205 manufactured by Tosoh Corporation; density 924 kg / m ³ , MFR 3.0 g / 10 min) (Hereinafter referred to as (C-1)) 20% by weight was premixed with a tumbler mixer and then melted with a single screw extruder (model PDA-50, manufactured by Plako Co., Ltd.) adjusted to a cylinder temperature of 180 ° C. It knead | mixed and granulated and the pellet of the ethylene-type polymer composition was obtained. The obtained pellets were laminated by the method shown in Evaluation method for ethylene polymer composition. The density, MFR, melt tension, and melting point were measured from the obtained ethylene polymer composition, and the neck-in and curl and the thickness of the ethylene polymer composition layer were evaluated during extrusion lamination molding. These evaluation results are shown in Table 3.

Example 2
Except having changed the compounding ratio of the composition into A-1 50 weight%, B-1 40 weight%, and C-1 10 weight%, it carried out similarly to Example 1, and obtained the pellet of the ethylene-type polymer composition. . The obtained pellets were laminated and evaluated in the same manner as in Example 1. These evaluation results are shown in Table 3.

Example 3
Except having changed the compounding ratio of the composition into A-1 50 weight%, B-1 10 weight%, and C-1 40 weight%, it obtained the pellet of the ethylene polymer composition like Example 1 was obtained. . The obtained pellets were laminated and evaluated in the same manner as in Example 1. These evaluation results are shown in Table 3.

Example 4
Except having changed the compounding ratio of the composition into A-1 80% by weight, B-1 10% by weight, and C-1 10% by weight, the pellets of the ethylene-based polymer composition were obtained in the same manner as in Example 1. . The obtained pellets were laminated and evaluated in the same manner as in Example 1. These evaluation results are shown in Table 3.

Example 5
The ethylene-α-olefin copolymer A-2 shown in Synthesis Example 2 was used instead of A-1 as the ethylene-α-olefin copolymer, and high-density polyethylene B was used instead of B-1 as the high-density polyethylene. -2 (trade name Nipolon Hard 2000 manufactured by Tosoh Corp .; density 959 kg / m ³ , MFR 13.5 g / 10 min) was used in the same manner as in Example 1 to obtain pellets of an ethylene-based polymer composition. The obtained pellets were laminated and evaluated in the same manner as in Example 1. These evaluation results are shown in Table 3.

Example 6
An ethylene polymer composition in the same manner as in Example 1 except that the ethylene-α-olefin copolymer A-3 shown in Synthesis Example 3 was used instead of A-1 as the ethylene-α-olefin copolymer. Pellets were obtained. The obtained pellets were laminated and evaluated in the same manner as in Example 1. These evaluation results are shown in Table 3.

Example 7
An ethylene polymer composition pellet was obtained in the same manner as in Example 1 except that high density polyethylene B-2 was used instead of B-1 as high density polyethylene. The obtained pellets were laminated and evaluated in the same manner as in Example 1. These evaluation results are shown in Table 3.

Example 8
Implemented except using high pressure method low density polyethylene C-2 (trade name Petrocene 203 manufactured by Tosoh Corporation; density 918 kg / m ³ , MFR 8.0 g / 10 min) instead of C-1 as high pressure method low density polyethylene In the same manner as in Example 1, pellets of an ethylene polymer composition were obtained. The obtained pellets were laminated and evaluated in the same manner as in Example 1. These evaluation results are shown in Table 3.

比較例１
エチレン−α−オレフィン共重合体としてＡ−１の代わりに合成例４に示したエチレン−α−オレフィン共重合体Ａ−４を使用した以外は実施例１と同様にしてエチレン系重合体組成物のペレットを得た。得られたペレットは、実施例１と同様にラミネート成形し評価を行った。これらの評価結果を表４に示す。

Comparative Example 1
An ethylene-based polymer composition as in Example 1 except that the ethylene-α-olefin copolymer A-4 shown in Synthesis Example 4 was used instead of A-1 as the ethylene-α-olefin copolymer. Pellets were obtained. The obtained pellets were laminated and evaluated in the same manner as in Example 1. These evaluation results are shown in Table 4.

  The obtained ethylene polymer composition had a large difference between the maximum value and the minimum value of the layer thickness of the laminate molded product, and the thickness stability was inferior.

Comparative Example 2
As the ethylene-α-olefin copolymer, the ethylene-α-olefin copolymer A-4 shown in Synthesis Example 2 was used instead of A-1, and the high-density polyethylene B- 3 (Tosoh Co., Ltd., product name Nipolon Hard 5700; density 953 kg / m ³ , MFR 1.0 g / 10 min) was used in the same manner as in Example 1 to obtain pellets of an ethylene polymer composition. The obtained pellets were laminated and evaluated in the same manner as in Example 1. These evaluation results are shown in Table 4.

  The obtained ethylene polymer composition had a large difference between the maximum value and the minimum value of the layer thickness of the laminate molded product, and the thickness stability was inferior.

Comparative Example 3
A pellet of an ethylene polymer composition was obtained in the same manner as in Example 1 except that the high-density polyethylene (B) was not blended and the blending ratio was changed to 80 wt% A-1 and 20 wt% C-1. . The obtained pellets were laminated and evaluated in the same manner as in Example 1. These evaluation results are shown in Table 4.

  The obtained ethylene polymer composition was inferior in heat resistance as compared with Examples 3 to 5 having the same density.

Comparative Example 4
The pellets of the ethylene-based polymer composition were prepared in the same manner as in Example 1 except that the high-pressure method low-density polyethylene (C) was not blended and the blending ratio was changed to 80 wt% A-1 and 20 wt% B-1. Obtained. The obtained pellets were laminated and evaluated in the same manner as in Example 1. These evaluation results are shown in Table 4.

The obtained ethylene polymer composition had a large neck-in and was inferior in laminate processability. Comparative Example 5
The ethylene-based polymer composition was the same as in Example 1 except that the ethylene-α-olefin copolymer (A) was not blended and the blending ratio was changed to 80 wt% B-1 and 20 wt% C-1. Pellets were obtained. The obtained pellets were laminated and evaluated in the same manner as in Example 1. These evaluation results are shown in Table 4.

  The resulting ethylene polymer composition had a large neck-in and was inferior in laminate processability.

Comparative Example 6
The pellets of the ethylene-based polymer composition were prepared in the same manner as in Example 1 except that the high-density polyethylene (B) and the high-pressure method low-density polyethylene (C) were not blended and the blending ratio was changed to A-1 100% by weight. Obtained. The obtained pellets were laminated and evaluated in the same manner as in Example 1. These evaluation results are shown in Table 4.

  The resulting ethylene polymer had a low gloss change temperature and poor heat resistance.

Comparative Example 7
Ethylene polymer in the same manner as in Example 1 except that the ethylene-α-olefin copolymer (A) and the high-pressure low-density polyethylene (C) were not blended, and the blending ratio was changed to 100 wt% B-1. A pellet of the composition was obtained. The obtained pellets were laminated and evaluated in the same manner as in Example 1. These evaluation results are shown in Table 4.

  The obtained ethylene-based polymer had a large neck-in and was inferior in laminate processability.

Comparative Example 8
Ethylene polymer composition in the same manner as in Example 1 except that the ethylene-α-olefin copolymer (A) and the high density polyethylene (B) were not blended and the blending ratio was changed to 100% by weight of C-2. Pellets were obtained. The obtained pellets were laminated and evaluated in the same manner as in Example 1. These evaluation results are shown in Table 4.

  The obtained ethylene polymer was inferior in heat resistance.

Claims (6)

An ethylene-α-olefin copolymer obtained by copolymerizing ethylene having a density of 920 kg / m ³ or more and 955 kg / m ³ or less, MFR 5 g / 10 min or more and less than 10 g / 10 min and α-olefin having 3 to 6 carbon atoms ( a) 50 to 80 wt%, density 955 kg / ^{m 3} greater than 975 kg / ^{m 3} or less, MFR5g / 10 min or more 40 g / 10 min than the high-density polyethylene (B) 10 to 40 wt% and a density 915 kg / ^{m 3} For extrusion lamination comprising 10 to 40% by weight of high-pressure method low density polyethylene (C) of 930 kg / m ³ or less, MFR 1.25 g / 10 min to 10 g / 10 min and satisfying the following requirements (a) to (d) Ethylene polymer composition.
(A) Melt tension measured at 160 ° C. 10 to 100 mN
(B) MFR4g / 10 min or more 17 g / 10 minutes or less (c) MFR (MFR _A) and high-density polyethylene ethylene -α- olefin copolymer (A) (B) MFR ( MFR B) of the ratio MFR _A / MFR _B is 0.25 to 4.0
(D) the ratio _MFR A / MFR _C of MFR of MFR (MFR _A) and the high-pressure low-density polyethylene ethylene -α- olefin copolymer (A) (C) (MFR C) is 0.25 to 4.0 The ethylene-based polymer composition according to claim 1, wherein the ethylene-α-olefin copolymer (A) satisfies the following requirement (e).
(E) 0.01 to 0.2 long chain branches having 6 or more carbon atoms per 1000 carbon atoms The ethylene-based polymer composition according to claim 1 or 2, wherein the ethylene-α-olefin copolymer (A) satisfies the following requirement (f).
(F) The ratio Mw / Mn of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is 2 to 5 The ethylene-α-olefin copolymer (A) is obtained by copolymerizing ethylene with an ethylene polymer having a vinyl group at the terminal obtained by polymerizing ethylene or ethylene and an olefin having 3 to 6 carbon atoms. A polyethylene monomer obtained by polymerizing a macromonomer composed of an ethylene copolymer having a group and having a number average molecular weight (Mn) of 2000 or more and ethylene or ethylene and an olefin having 3 to 6 carbon atoms The ethylene polymer composition according to claim 1, wherein the ethylene polymer composition is a polymer. A laminate comprising at least one layer made of the ethylene-based polymer composition according to claim 1. The laminate according to claim 5, wherein the following requirement (g) is satisfied.
(G) a maximum value d _H and the minimum value d _L thickness of consisting ethylene polymer composition layer satisfies the relation of equation (1).
(D _H −d _L ) / d _L ≦ 0.15 (1)