JP2008230068A - Laminate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminate excellent in low-temperature heat sealability, hot tack performance, high-speed liquid packing performance and mechanical strengths. <P>SOLUTION: The laminate comprises a layer formed from a resin composition containing 60-99 wt.% of an ethylene-based polymer, which is a copolymer between ethylene and a 4-10C α-olefin and satisfies the following requirements (I)-(IV) simultaneously, and 1-40 wt.% of a high pressure low-density polyethylene (wherein the total of the ethylene-based polymer and the high-pressure low-density polyethylene is 100 wt.%). Here the requirement (I): MFR is in the range of 1.0-100 g/10 min, (II): density(D) is in the range of 860-925 kg/m<SP>3</SP>, (III): Mw/Mn is in the range of 1.50-3.00, and (IV): the ratio (H/W) of the height (H) of the peak with the highest peak intensity to the width (W) at the 1/2 height of that peak in the elution curve obtained by TREF and the density (D) satisfy a specific relationship. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a laminate. In detail, it is related with the laminated body which has a layer formed from the resin composition containing a specific ethylene-type polymer and a high-pressure-process low-density polyethylene.

  Ethylene polymers are molded by various molding methods and are used for various purposes. Various ethylene-based polymers that are characterized by moldability and molded product performance have been developed.

  An ethylene polymer obtained using a Ziegler catalyst is excellent in mechanical strength such as tensile strength, tear strength or impact strength. However, since the composition distribution is wide, a molded article such as a film is sticky, resulting in poor blocking resistance. If the density of the ethylene-based polymer is increased, the blocking resistance is improved, but in that case, there is a problem that the low-temperature heat sealability and flexibility are deteriorated.

In order to solve such problems, various ethylene polymers using a metallocene catalyst which is a homogeneous catalyst (single site catalyst) have been disclosed.
Patent Document 1 (Japanese Patent Laid-Open No. 2005-97481) discloses an ethylene polymer obtained by gas phase polymerization in the presence of a catalyst comprising racemic-ethylenebis (1-indenyl) zirconium diphenoxide. JP-A-9-111208 discloses an ethylene polymer (trade name EXACT manufactured by Exxon Chemical Co., Ltd.) obtained by using a metallocene compound as a polymerization catalyst in Patent Document 3 (JP-A-11-269324). Is ethylene-bis (4
An ethylene polymer obtained by high-pressure ionic polymerization in the presence of a catalyst comprising 5,6,7-tetrahydroindenyl) zirconium dichloride and methylalumoxane is disclosed in Patent Document 4 (Japanese Patent Laid-Open No. 2002-3661). Discloses an ethylene polymer obtained using a catalyst comprising bis (n-butylcyclopentadienyl) zirconium dichloride and methylalumoxane. Although these ethylene polymers have a narrower composition distribution than ethylene polymers obtained using conventional Ziegler catalysts, the composition distribution is still wide in order to completely eliminate blocking properties.

As a result of studies conducted in view of such circumstances, the present inventors have found that a specific MFR range and a specific density range are satisfied, a molecular weight distribution satisfies a specific range, and is defined by temperature rising elution fractionation (TREF). / W and density satisfy a specific relationship, preferably [η] and MFR satisfy a specific relationship, and the ethylene polymer particularly excellent in blocking resistance and low temperature heat sealability as a molded product Has already been proposed. (PCT application, PCT / JP2006 / 318869)
JP 200597481 A JP-A-9-111208 JP-A-11-269324 JP-A-2002-3661

  An object of the present invention is to provide a laminate excellent in low-temperature heat-sealing property, hot tack property, and high-speed liquid filling property using a resin composition containing a specific ethylene polymer and high-pressure low-density polyethylene. .

  The present inventors have found that a laminate having a layer comprising a resin composition containing a specific ethylene polymer and a high-pressure low-density polyethylene is excellent in low-temperature heat sealability, hot tackiness, and high-speed liquid filling properties. The present invention has been completed.

That is, the laminate of the present invention is
A copolymer of ethylene and an α-olefin having 4 to 10 carbon atoms, which satisfies the following requirements (I) to (IV) at the same time: 60 to 99% by weight, and high pressure method low density polyethylene 1 to 40 It is characterized by including a layer formed from a resin composition containing wt% (however, the total of the ethylene polymer and the high-pressure method low-density polyethylene is 100 wt%).
(I) The melt flow rate (MFR) at a load of 2.16 kg at 190 ° C. is in the range of 1.0 to 100 g / 10 min.
(II) The density (D) is in the range of 860 to 925 kg / m ³ .
(III) The ratio (Mw / Mn) between the weight average molecular weight and the number average molecular weight measured by GPC is 1.
The range is from 50 to 3.00.
(IV) In the elution curve obtained by temperature rising elution fractionation (TREF), the peak height (H) with the strongest peak intensity and the width (W) at half the height of the strongest peak intensity The ratio (H / W) and density (D) of the following relational expression (I) according to the MFR of requirement (I)
Eq-1) or (Eq-2) is satisfied.
[When 1.0 ≦ MFR ≦ 10]
0.0163 × D-14.02 ≦ Log ₁₀ (H / W) ≦ 0.0163 × D-13.30
(Eq-1)
[When 10 <MFR ≦ 100]
0.0163 × D-14.10 ≦ Log ₁₀ (H / W) ≦ 0.0163 × D-13.40 (Eq-2)
The ethylene polymer preferably satisfies the following requirement (V).
(V) Intrinsic viscosity [[η] (dl / g)] measured in 135 ° C. decalin and MFR satisfy the following relational expression (Eq-3).
−0.21 × Log ₁₀ MFR + 0.16 ≦ Log ₁₀ [η] ≦ −0.21 × Log ₁₀ MFR + 0.31
... (Eq-3)

  The laminate of the present invention includes a layer formed from a resin composition containing an ethylene-based polymer and a high-pressure process low-density polyethylene, and thus has excellent low-temperature heat sealability, hot tackiness, and high-speed liquid filling properties, and further has mechanical strength Also excellent.

Next, the present invention will be specifically described.
The laminate of the present invention is a copolymer of ethylene and an α-olefin having 4 to 10 carbon atoms, and satisfies the following requirements (I) to (IV): 60 to 99% by weight of ethylene polymer and high pressure It includes a layer formed from a resin composition containing 1 to 40% by weight of a method low density polyethylene (however, the total of the ethylene polymer and the high pressure method low density polyethylene is 100% by weight). .
(I) The melt flow rate (MFR) at a load of 2.16 kg at 190 ° C. is in the range of 1.0 to 100 g / 10 min.
(II) The density (D) is in the range of 860 to 925 kg / m ³ .
(III) The ratio (Mw / Mn) between the weight average molecular weight and the number average molecular weight measured by GPC is 1.
The range is from 50 to 3.00.
(IV) In the elution curve obtained by temperature rising elution fractionation (TREF), the peak height (H) with the strongest peak intensity and the width (W) at half the height of the strongest peak intensity The ratio (H / W) and density (D) of the following relational expression (I) according to the MFR of requirement (I)
Eq-1) or (Eq-2) is satisfied.
[When 1.0 ≦ MFR ≦ 10]
0.0163 × D-14.02 ≦ Log ₁₀ (H / W) ≦ 0.0163 × D-13.30
(Eq-1)
[When 10 <MFR ≦ 100]
0.0163 × D-14.10 ≦ Log ₁₀ (H / W) ≦ 0.0163 × D-13.40 (Eq-2)
<Ethylene polymer>
The ethylene polymer according to the present invention is a copolymer of ethylene and an α-olefin having 4 to 10 carbon atoms, preferably ethylene and an α-olefin having 6 to 10 carbon atoms. Examples of the α-olefin having 4 to 10 carbon atoms used for copolymerization with ethylene include 1-butene, 1-hexene, 4-methyl-1-pentene, 1-octene and 1-decene. When the α-olefin has 4 or more carbon atoms, the probability that the α-olefin is incorporated into the crystal is low (Polymer, VOL31, 1999, 1999), and therefore the mechanical strength is excellent. When the α-olefin has 10 or less carbon atoms, the flow activation energy is small, and the viscosity change during molding is small.

The type of α-olefin in the ethylene polymer is usually a ¹³ C-NMR spectrum of a sample in which about 200 mg of the ethylene polymer is uniformly dissolved in 1 ml of hexachlorobutadiene in a 10 mmφ sample tube. It can be identified by measuring under measurement conditions of temperature 120 ° C., frequency 25.05 MHz, spectrum width 1500 Hz, pulse repetition time 4.2 seconds, and 45 ° pulse width 6 μsec.

Such an ethylene polymer satisfies the following requirements (I) to (IV) at the same time.
(I) Melt flow rate (MFR) at 190 ° C. under a load of 2.16 kg is 1.0 to 100 g / 10 min, preferably 1.0 to 30.0 g / 10 min, more preferably 1.0 to 20.0 g / 10 min, particularly preferably The range is 5.0 to 20.0 g / 10 minutes.

  When the melt flow rate (MFR) of the ethylene-based polymer is 1.0 g / 10 min or more, the shear viscosity is not too high and the moldability is good. When the melt flow rate (MFR) is 100 g / 10 min or less, the resulting ethylene polymer has good tensile strength.

The melt flow rate (MFR) strongly depends on the molecular weight. The smaller the melt flow rate (MFR), the larger the molecular weight, and the higher the melt flow rate (MFR), the smaller the molecular weight. Further, it is known that the molecular weight of an ethylene polymer is determined by the composition ratio (hydrogen / ethylene) of hydrogen and ethylene in the polymerization system (for example, Kazuo Soga, KODANSHA "CATALYTIC OLEFIN POLYMERIZATION", p376 (1990)). For this reason, by increasing / decreasing hydrogen / ethylene, it is possible to produce an ethylene polymer having a melt flow rate (MFR) that is the upper limit or the lower limit of the requirement (I) of the present invention.

In the present invention, the melt flow rate (MFR) is a value measured under conditions of 190 ° C. and 2.16 kg load according to ASTM D1238-89.
(II) Density (D) is 860~925 kg / m ^3, preferably in 860~920 kg / m ^3, more preferably 865~915kg / m ^3, particularly preferably in the range of 870~910 kg / m ³ .

When the density (D) is 860 kg / m ³ or more, the resulting ethylene polymer has good blocking resistance, and when the density (D) is 925 kg / m ³ or less, the resulting ethylene polymer Good low temperature sealing.

The density depends on the α-olefin content of the ethylene polymer. The smaller the α-olefin content, the higher the density, and the higher the α-olefin content, the lower the density. It is also known that the α-olefin content in an ethylene polymer is determined by the composition ratio of α-olefin and ethylene (α-olefin / ethylene) in the polymerization system (for example, Walter Kaminsky, Makromol). Chem. 193, p.606 (1992)). For this reason, it is possible to produce an ethylene polymer having an upper limit or a lower limit density of the requirement (II) of the present invention by increasing or decreasing α-olefin / ethylene.

Density (D), using a press molding machine manufactured by Shinto Metal Industries, preheating temperature 190 ° C, preheating time 5 minutes, heating temperature 190 ° C, heating time 2 minutes, heating pressure 100 kg / cm ² , cooling temperature 20 ° C, It is obtained by measuring with a density gradient tube using a 0.5 mm-thick press sheet press-molded under a cooling pressure of 100 kg / cm ^{2 for} a cooling time of 5 minutes.

  (III) The ratio (Mw / Mn) of the weight average molecular weight and number average molecular weight measured by GPC is 1.50 or more and 3.00 or less, preferably 1.50 or more and 2.50 or less, more preferably 1.50 or more and 2.20 or less, and particularly preferably 1.60 or more and 2.10 or less. It is in the range.

When Mw / Mn is 1.50 or more, the moldability of the resulting ethylene polymer is good, and when Mw / Mn is 3.00 or less, the resulting ethylene polymer has good impact strength.
In the present invention, the ratio (Mw / Mn) between the weight average molecular weight and the number average molecular weight was measured as follows using GPC-150C manufactured by Waters. Separation columns are TSKgel GMH6-HT and TSKgel.
GMH6-HTL, the column size is 7.5 mm inside diameter and 600 mm length, the column temperature is 140 ° C, the mobile phase is o-dichlorobenzene (Wako Pure Chemical Industries) and BHT (Takeda) as an antioxidant The drug was moved at 1.0 ml / min using 0.025 wt%, the sample concentration was 0.1 wt%, the sample injection amount was 500 microliters, and a differential refractometer was used as the detector. Standard polystyrene used was manufactured by Tosoh Corporation for molecular weights of Mw ≦ 1000 and Mw ≧ 4 × 10 ⁶ , and used by Pressure Chemical Co. for 1000 ≦ Mw ≦ 4 × 10 ⁶ . The molecular weight calculation is a value calibrated to polyethylene after universal calibration.

(IV) In the elution curve obtained by temperature rising elution fractionation (TREF), the peak height (H) with the strongest peak intensity and the width (W) at 1/2 the peak with the strongest peak intensity The ratio (H / W) and density (D) satisfy the following relational expressions (Eq-1) to (Eq-2) according to the MFR. Here, MFR is the melt flow rate of the ethylene polymer at a load of 2.16 kg at 190 ° C. (requirement (I)).
[When 1.0 ≦ MFR ≦ 10]
0.0163 × D−14.02 ≦ Log ₁₀ (H / W) ≦ 0.0163 × D−13.30… (Eq-1)
[When 10 <MFR ≦ 100]
0.0163 × D−14.10 ≦ Log ₁₀ (H / W) ≦ 0.0163 × D−13.40… (Eq-2)
Preferably, the following relational expressions (Eq-1 ′) to (Eq-2 ′) are satisfied.
[When 1.0 ≦ MFR ≦ 10]
0.0163 × D−13.92 ≦ Log ₁₀ (H / W) ≦ 0.0163 × D−13.30… (Eq-1 ')
[When 10 <MFR ≦ 100]
0.0163 × D−14.02 ≦ Log ₁₀ (H / W) ≦ 0.0163 × D−13.40… (Eq-2 ')
In temperature rising elution fractionation (TREF), components with higher α-olefin content elute at lower temperatures,
Components with lower α-olefin content elute at higher temperatures. H / W is temperature rising elution fractionation (TREF
In the elution curve obtained by), the peak height (H) with the strongest peak intensity and the width (W) at 1/2 the height of the peak with the strongest peak intensity are equivalent. As compared with an ethylene polymer having a density of α, the larger the H / W, the more uniformly the α-olefin is introduced into the molecular chain and the narrower the composition distribution. Therefore, when Log ₁₀ (H / W) is 0.0163 × D-14.02 or more when 1.0 ≦ MFR ≦ 10, and 0.0163 × D-14.10 or more when 10 ≦ MFR ≦ 100, the resulting ethylene polymer The composition distribution is narrow and no sticky component is generated, so that the blocking resistance is excellent.

It is known that H / W strongly depends on the composition distribution of the obtained ethylene-based polymer, and this composition distribution becomes narrower when the active sites of the catalyst become uniform and becomes wider when it becomes nonuniform. As one of the factors governing the uniformity of the catalytic activity point, a compound added as a compound having a co-catalytic action (B component described later, MMAO manufactured by Tosoh Finechem in Example 1) and a crosslinking added as a main catalyst Molar ratio of the metallocene compound (component A described later, di (p-tolyl) methylene (cyclopentadienyl) (octamethyloctahydrodibenzofluorenyl) zirconium dichloride in Example 1) ([component B] / [A Component]). By increasing / decreasing [B component] / [A component], it is possible to produce an ethylene polymer having an upper limit or lower limit H / W of the requirement [4] of the present invention.

In the present invention, H / W was determined as follows.
First, an elution curve by temperature rising elution fractionation (TREF) was measured as follows using a cross fractionation chromatograph CFCF-150A manufactured by Mitsubishi Oil Chemical Co., Ltd. The measurement sample is dissolved at 140 ° C. using a solvent (o-dichlorobenzene) so as to have a concentration of 4 mg / ml, and this is injected into the sample loop in the measurement apparatus. The sample solution is injected into a TREF separation column (a stainless steel column attached with a device filled with glass beads as an inert carrier, the capacity is 0.88 ml, the pipe capacity is 0.07 ml). Next, the sample solution is cooled at a rate of 1 ° C./min from 140 ° C. to 0 ° C., and coated on an inert carrier. At this time, a polymer layer is formed on the surface of the inert carrier in the order of the high crystalline component to the low crystalline component. After the TREF separation column is held at 0 ° C. for another 30 minutes, 2 ml of the component dissolved at the temperature of 0 ° C. is transferred from the TREF separation column to the SEC separation column (Showex AT Shodex AT -806MS x 3). While the molecular size fractionation is performed in the SEC separation column, the TREF separation column has the following elution temperature (5
℃) and kept at that temperature for about 30 minutes. The elution temperature is raised stepwise at the following temperature.

[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, 102, 120, 140 ° C
The molecular weight of the components eluted at each temperature was measured, and the molecular weight of polyethylene was determined using a general calibration curve. The SEC temperature is 140 ° C and the data sampling time is 0.50 seconds. The sample solution that has passed through the SEC separation column is measured for absorbance in proportion to the polymer concentration with an infrared spectrophotometer (wavelength: 3.42 μm, 2924 cm ⁻¹ ), and chromatograms for each elution temperature section are obtained. Using the built-in data processing software, the base line of the chromatogram of each elution temperature segment obtained by the above measurement is drawn and processed. The area of each chromatogram is integrated and an integrated elution curve is calculated. Also, the differential elution curve is calculated by differentiating the integral elution curve with temperature.

  Next, the resulting differential elution curve is plotted. The horizontal axis is the elution temperature of 89.3 mm per 100 ° C, the vertical axis is the differential amount (the total integrated elution amount is normalized to 1.0, and the change at 1 ° C is the differential amount. The value obtained by dividing the peak height (mm) of this differential elution curve by the width (mm) of 1/2 height was defined as H / W.

It is preferable that the ethylene copolymer according to the present invention further satisfies the following requirement (V) in addition to the above requirements (I) to (IV).
(V) Intrinsic viscosity [η] (dl / g) measured in decalin at 135 ° C and 2.16 kg at 190 ° C
The melt flow rate (MFR) under load satisfies the following relational expression (Eq-3).

-0.21 x Log ₁₀ MFR + 0.16 ≤ Log ₁₀ [η] ≤ -0.21 x Log ₁₀ MFR + 0.31… (Eq-3)
It is known that the relationship between the intrinsic viscosity ([η]) and the melt flow rate (MFR) is strongly governed by the long chain branching structure in the molecular chain (for example, Kenzo Shirayama, Polymer Chemistry, Vol. 28, No.310
, pp156-160 (1971)). When comparing ethylene-based polymers having the same melt flow rate (MFR), when long-chain branching is introduced, the molecular chain spread in the solution is reduced, so that the intrinsic viscosity ([η]) is reduced. When Log ₁₀ [η] is (−0.21 × Log ₁₀ MFR + 0.26) or more, since there is no long chain branching in the molecular chain, the tear strength is excellent.

Therefore, with regard to the requirement (V), when the ethylene-based polymer is developed for use as a molded product, a preferable embodiment is divided into two depending on what characteristics are required. That is, short-chain branching caused by an α-olefin that is subjected to a copolymerization reaction together with ethylene (for example, when 1-butene is used as the α-olefin, an ethyl group is introduced as a short-chain branching). An ethylene polymer having a branched structure and containing almost no long chain branched structure produced via a macromonomer having a vinyl group at the terminal (hereinafter sometimes referred to as “short chain branched ethylene polymer”) .) Is desirable, an ethylene polymer that satisfies the range represented by the following relational expression (Eq-3a) is preferable.

-0.21 x Log ₁₀ MFR + 0.26 ≤ Log ₁₀ [η] ≤ -0.21 x Log ₁₀ MFR + 0.31… (Eq-3a)
On the other hand, when an ethylene polymer containing a small amount of a long-chain branched structure content generated via a macromonomer (hereinafter sometimes abbreviated as “long-chain branched ethylene polymer”) is desired. Is preferably an ethylene polymer satisfying the range represented by the following relational expression (Eq-3b) as a preferred requirement (V). Such a long-chain branched ethylene polymer is more elastic than a short-chain branched ethylene polymer in terms of slow deformation in the molten state, and is preferred in fields where good moldability is required. Can be applied.

-0.21 x Log ₁₀ MFR + 0.16 ≤ Log ₁₀ [η] <-0.21 x Log ₁₀ MFR + 0.26… (Eq-3b)
In the case of coordination polymerization as in the examples described later, the long chain branching structure in the ethylene polymer is reinserted by a molecular chain (macromonomer) having a terminal vinyl group generated by a β-hydrogen elimination reaction. It is thought that it generates. For this reason, by increasing / decreasing the ratio of macromonomer concentration to ethylene concentration ([macromonomer] / [ethylene]) in the solution, the amount of long chain branching in the ethylene-based polymer is increased or decreased. It is possible to produce an ethylene polymer having an intrinsic viscosity [η] that is an upper limit or a lower limit of the requirement (V). Generally, when [macromonomer] / [ethylene] is high, the amount of long chain branching in the ethylene polymer increases, and when [macromonomer] / [ethylene] is low, the amount of long chain branching in the ethylene polymer is descend. Specific methods for increasing / decreasing [macromonomer] / [ethylene] in the solution include the following methods.

[1] Polymerization temperature The higher the polymerization temperature, the easier the β-hydrogen elimination reaction occurs. Therefore, if the polymerization temperature is increased, [macromonomer] / [ethylene] increases and the amount of long-chain branching in the ethylene polymer increases.

[2] Polymer concentration The higher the polymer concentration in the solution, the higher the macromonomer concentration, so the [macromonomer] / [ethylene] increases and the amount of long-chain branching in the ethylene polymer increases. To do.

[3] Ethylene conversion rate If the ethylene conversion rate is increased, the ethylene concentration in the solution is lowered, so that [macromonomer] / [ethylene] increases and the amount of long-chain branching in the ethylene polymer increases.

[4] Solvent type If the polymerization solvent is a low-boiling solvent, the ethylene concentration in the solution decreases, so the [macromonomer] / [ethylene] increases and the amount of long-chain branching in the ethylene polymer increases. .

In addition to controlling the β-hydrogen elimination reaction, the amount of long chain branching in the ethylene polymer can be increased or decreased by controlling the chain transfer reaction to Al, etc. Can also be changed.

The intrinsic viscosity [[η] (dl / g)] was measured as follows using a decalin solvent. About 20 mg of an ethylene polymer is dissolved in 15 ml of decalin, and the specific viscosity η _sp is measured in an oil bath at 135 ° C. After adding 5 ml of decalin solvent to the decalin solution for dilution, the specific viscosity η _sp is measured in the same manner. This dilution operation is further repeated twice, and the value of η _sp / C when the concentration (C) is extrapolated to 0 is obtained as the intrinsic viscosity. That is, the intrinsic viscosity [η] is represented by the following formula.

[η] = lim (η _sp / C) (C → 0)
The ethylene-based polymer of the present invention includes, for example, (A) a bridged metallocene compound represented by the following general formula [I], and (B) (b-1) an organoaluminum oxy compound,
(b-2) a compound that reacts with the metallocene compound (A) to form an ion pair, and
(b-3) one or more selected from ethylene and α-olefin in the presence of an olefin polymerization catalyst consisting of at least one compound selected from organic aluminum compounds (sometimes referred to as co-catalyst) Can be produced by solution polymerization (sometimes referred to as “high temperature solution polymerization” in the following description) at a temperature of 120 to 300 ° C. in the presence of a solvent. However, the production method of the ethylene polymer according to the present invention is not limited to the above production method as long as the ethylene polymer defined in the claims of the present application is satisfied. For example, a metallocene compound having a structure different from that of the general formula [I] may be used, a promoter different from the component (B) may be used, or two or more known ethylene polymers may be used. You may prepare by methods, such as a reactor blend and a physical blend.

(In the above general formula [I], M represents a transition metal, p represents the valence of the transition metal, X may be the same or different, and each represents a hydrogen atom, a halogen atom or a hydrocarbon group, R ¹ and R ² represent a π-electron conjugated ligand coordinated to M, which may be the same or different, and Q is a divalent bridge that bridges ^two π-electron conjugated ligands R ¹ and R ² Represents a group of
In the general formula [I], examples of the transition metal represented by M include Zr, Ti, Hf, V, Nb, Ta, and Cr. Preferred transition metals are Zr, Ti, and Hf, and more preferable. The transition metal is Zr or Hf.

In the general formula [I], π-electron conjugated ligands represented by R ¹ and R ² include η-cyclopentadienyl structure, η-benzene structure, η-cycloheptatrienyl structure, and η-cyclo Examples thereof include a ligand having an octatetraene structure, and a particularly preferable ligand is a ligand having a η-cyclopentadienyl structure. Examples of the ligand having an η-cyclopentadienyl structure include a cyclopentadienyl group, an indenyl group, a hydrogenated indenyl group, and a fluorenyl group. These groups are further substituted with a hydrocarbon group such as a halogen atom, alkyl, aryl, aralkyl, alkoxy or aryloxy, a hydrocarbon group-containing silyl group such as a trialkylsilyl group, a chain or cyclic alkylene group, etc. Also good.

In the general formula [I], the group for bridging R ¹ and R ² represented by Q is not particularly limited as long as it is a divalent group. For example, a linear or branched alkylene group, unsubstituted or Examples thereof include a substituted cycloalkylene group, an alkylidene group, an unsubstituted or substituted cycloalkylidene group, an unsubstituted or substituted phenylene group, a silylene group, a dialkyl-substituted silylene group, a germyl group, and a dialkyl-substituted germyl group.

In the examples described later, di (p-) is used as the metallocene compound satisfying the above general formula [I].
A metallocene complex represented by (tolyl) methylene (cyclopentadienyl) (octamethyloctahydrodibenzofluorenyl) zirconium dichloride is used, but the metallocene compound according to the present invention is not limited thereto.

Next, a preferred embodiment when the metallocene compound (A) described above is used as a polymerization catalyst component for producing the ethylene-based polymer of the present invention will be described.
When the metallocene catalyst containing the metallocene compound (A) is used as an olefin polymerization catalyst for producing an ethylene polymer, the polymerization catalyst is, as described above, (A) the metallocene represented by the general formula [I] A compound, and (B) (b-1) an organoaluminum oxy compound, (b-2) a compound that reacts with the metallocene compound (A) to form an ion pair, and (b-3) an organoaluminum compound. It is preferably composed of at least one compound. Here, as the catalyst component (B), from the viewpoint of the polymerization activity and the properties of the generated olefin polymer,
Any of the following [c1] to [c4] is preferably used.
[c1] (b-1) Only organoaluminum oxy compounds,
[c2] (b-1) an organoaluminum oxy compound and (b-3) an organoaluminum compound,
[c3] (b-2) a compound that reacts with the metallocene compound (A) to form an ion pair, and (b-3) an organoaluminum compound,
[c4] (b-1) A compound that reacts with an organoaluminum oxy compound and (b-2) the metallocene compound (A) to form an ion pair.

However, when the metallocene compound in which Q is a silylene group in the general formula [I] is used as the component (A), the component (B) is an ion that reacts with the metallocene compound (A) (b-2) A compound that forms a pair is not used. Therefore, only [c1] and [c2] are adopted also in the above-mentioned preferable component (B); [c1] to [c4].

Hereinafter, each component which can comprise (B) component is demonstrated concretely.
(b-1) Organoaluminum oxy compound As the organoaluminum oxy compound (b-1), a conventionally known aluminoxane can be used as it is. Specifically, the following general formula [II] and / or general formula [III]

(In the formula [II] or [III], R represents a hydrocarbon group having 1 to 10 carbon atoms, and n represents an integer of 2 or more.)
In particular, a methylaluminoxane in which R is a methyl group and n is 3 or more, preferably 10 or more is used. (In the general formula [II] or [III], the organoaluminum oxy compound in which R is a methyl group may be referred to as “methylaluminoxane” hereinafter.)
Methylaluminoxane is an organoaluminum oxy compound that has been widely used in the polyolefin industry due to its availability and high polymerization activity, but it is difficult to dissolve in saturated hydrocarbons, and it has a huge environmental impact, such as toluene and benzene. Has been used as an aromatic hydrocarbon solution. Under such circumstances, methylaluminoxane analogues that are soluble in saturated hydrocarbons have been developed. Examples of such analogs include modified methylaluminoxanes represented by the following general formula [IV]. In the present invention, such a modified methylaluminoxane is also included as the organoaluminum oxy compound (b-1).

(In the formula [IV], R represents a hydrocarbon group having 2 to 20 carbon atoms, and m and n represent an integer of 2 or more.)
The modified methylaluminoxane represented by the general formula [IV] is prepared using trimethylaluminum and an alkylaluminum other than trimethylaluminum (for example, the production method is disclosed in US4960878 and US5041584), and from a manufacturer such as Tosoh Finechem Co., Ltd. Products prepared using aluminum and triisobutylaluminum, in which R is an isobutyl group, are commercially produced under trade names such as MMAO and TMAO (see, for example, Tosoh Research and Technical Report Vol. 47, 55 (2003)). ). However, the present applicant has confirmed that even if MMAO or TMAO is polymerized in the form of a saturated hydrocarbon solution outside the technical scope of the high-temperature solution polymerization method of the present invention, the activity exceeding methylaluminoxane cannot be achieved. . According to the high temperature solution polymerization method according to the present invention, high polymerization activity is exhibited even when a saturated hydrocarbon solution of the modified aluminoxane represented by the general formula [IV] is used.

In the high temperature solution polymerization according to the present invention, a benzene-insoluble organoaluminum oxy compound exemplified in JP-A-2-78687 can also be applied as the organoaluminum oxy compound (b-1).

Furthermore, examples of the organoaluminum oxy compound (b-1) used in the present invention include an organoaluminum oxy compound containing boron represented by the following general formula [V].

(In the formula [V], Rc represents a hydrocarbon group having 1 to 10 carbon atoms. Rd may be the same or different from each other, and may be a hydrogen atom, a halogen atom or a carbon atom having 1 to 10 carbon atoms. Indicates a hydrogen group.
)
Note that a slight amount of organoaluminum compound may be mixed in the above-described (b-1) organoaluminum oxy compound.
(b-2) Compound that reacts with metallocene compound (A) to form an ion pair Compound (b-2) that reacts with metallocene compound (A) to form an ion pair (hereinafter abbreviated as "ionic compound") Are disclosed in JP-A-1-501950, JP-A-1-502036, JP-A-3-17905, JP-A-3-179006, JP-A-3-207703, Examples include Lewis acids, ionic compounds, borane compounds, and carborane compounds described in Kaihei 3-207704, USP5321106, and the like. In addition, ionic compounds (b-2)
Can also include heteropoly compounds and isopoly compounds.

In the present invention, the ionic compound (b-2) preferably employed is a compound represented by the following general formula [VI].

In the formula [VI], R ^{e +} includes H ⁺ , carbenium cation, oxonium cation, ammonium cation, phosphonium cation, cycloheptyltrienyl cation, ferrocenium cation having a transition metal, and the like. Rf to Ri may be the same as or different from each other, and are an organic group, preferably an aryl group.

  Specific examples of the carbenium cation include trisubstituted carbenium cations such as triphenylcarbenium cation, tris (methylphenyl) carbenium cation, and tris (dimethylphenyl) carbenium cation.

Specific examples of the ammonium cation include trialkylammonium cations such as trimethylammonium cation, triethylammonium cation, tri (n-propyl) ammonium cation, triisopropylammonium cation, tri (n-butyl) ammonium cation, and triisobutylammonium cation. N, N-dimethylanilinium cation, N, N-diethylanilinium cation, N, N-2,4,6-pentamethylanilinium cation, N, N-dialkylanilinium cation, diisopropylammonium cation, dicyclohexyl And dialkyl ammonium cations such as ammonium cations.

  Specific examples of the phosphonium cation include triarylphosphonium cations such as triphenylphosphonium cation, tris (methylphenyl) phosphonium cation, and tris (dimethylphenyl) phosphonium cation.

Among the above, as R ^{e +} , a carbenium cation, an ammonium cation, and the like are preferable, and a triphenylcarbenium cation, an N, N-dimethylanilinium cation, and an N, N-diethylanilinium cation are particularly preferable.

Specific examples of the ionic compound (b-2) which is a carbenium salt include triphenylcarbenium tetraphenylborate, triphenylcarbeniumtetrakis (pentafluorophenyl) borate, triphenylcarbeniumtetrakis (3,5- Examples thereof include ditrifluoromethylphenyl) borate, tris (4-methylphenyl) carbenium tetrakis (pentafluorophenyl) borate, and tris (3,5-dimethylphenyl) carbeniumtetrakis (pentafluorophenyl) borate.

Examples of the ionic compound (b-2) that is an ammonium salt include a trialkyl-substituted ammonium salt, an N, N-dialkylanilinium salt, and a dialkylammonium salt.

Specific examples of the ionic compound (b-2) which is a trialkyl-substituted ammonium salt include triethylammonium tetraphenylborate, tripropylammonium tetraphenylborate, tri (n-butyl) ammonium tetraphenylborate, and trimethylammonium. Tetrakis (p-tolyl) borate, trimethylammonium tetrakis (o-tolyl) borate, tri (n-butyl) ammonium tetrakis (pentafluorophenyl) borate, triethylammonium tetrakis (pentafluorophenyl) borate, tripropylammonium tetrakis (pentafluoro) Phenyl) borate, tripropylammonium tetrakis (2,4-dimethylphenyl) borate, tri (n-butyl) ammonium tetrakis (3,5-dimethylphenyl) borate, tri (n- Chill) ammonium tetrakis (4-trifluoromethylphenyl) borate, tri (n- butyl) ammonium tetrakis (3,5-ditrifluoromethylphenyl) borate, tri (n- butyl) ammonium tetrakis (o-tolyl)
Borate, dioctadecylmethylammonium tetraphenylborate, dioctadecylmethylammonium tetrakis (p-tolyl) borate, dioctadecylmethylammonium tetrakis (o-tolyl) borate, dioctadecylmethylammonium tetrakis (pentafluorophenyl) borate, dioctadecylmethylammonium Tetrakis (2,4-dimethylphenyl) borate, dioctadecylmethylammonium tetrakis (3,5-dimethylphenyl) borate, dioctadecylmethylammonium tetrakis (4-trifluoromethylphenyl) borate, dioctadecylmethylammonium tetrakis (3,5 -Ditrifluoromethylphenyl) borate, dioctadecylmethylammonium and the like.

Specific examples of the ionic compound (b-2) which is an N, N-dialkylanilinium salt include N, N-dimethylanilinium tetraphenylborate, N, N-dimethylanilinium tetrakis (pentafluorophenyl). ) Borate, N, N-dimethylanilinium tetrakis (3,5-ditrifluoromethylphenyl) borate, N, N-diethylanilinium tetraphenylborate, N, N-diethylanilinium tetrakis (pentafluorophenyl) borate, N , N-diethylanilinium tetrakis (3,5-ditrifluoromethylphenyl) borate, N, N-2,4,6-pentamethylanilinium tetraphenylborate, N, N-2,4,6-pentamethylanily And nitrotetrakis (pentafluorophenyl) borate.

Specific examples of the dialkylammonium salt include di (1-propyl) ammonium tetrakis (pentafluorophenyl) borate and dicyclohexylammonium tetraphenylborate.

As the other ionic compound (b-2), an ionic compound disclosed by the present applicant (Japanese Patent Laid-Open No. 2004-51676) can also be used without limitation.
The ionic compound (b-2) may be used alone or in combination of two or more.
(b-3) Organoaluminum Compound Forming an Olefin Polymerization Catalyst (b-3) Examples of the organoaluminum compound include an organoaluminum compound represented by the following general formula [VII] and a general formula [VIII] A complex alkylated product of a Group 1 metal and aluminum can be used.

R ^a _m Al (OR ^b ) _n H _p X _q … [VII]
(In the formula [VII], R ^a and R ^b may be the same or different from each other, and each represents a hydrocarbon group having 1 to 15 carbon atoms, preferably 1 to 4 carbon atoms, X represents a halogen atom, m is 0 <m ≦ 3, n is 0 ≦ n <3, p is 0 ≦ p <3, q is 0 ≦ q <3, and m + n + p + q = 3.)
Specific examples of the organoaluminum compound represented by the general formula [VII] include tri-n-alkylaluminums such as trimethylaluminum, triethylaluminum, tri-n-butylaluminum, trihexylaluminum, and trioctylaluminum; Tri-branched alkyl aluminums such as triisobutylaluminum, trisec-butylaluminum, tritert-butylaluminum, tri-2-methylbutylaluminum, tri-3-methylhexylaluminum, tri-2-ethylhexylaluminum; tricyclohexylaluminum, tricyclooctyl Tricycloalkyl aluminum such as aluminum; Triaryl aluminum such as triphenyl aluminum and tolyl aluminum; Mini um hydride, dialkylaluminum hydride such as diisobutylaluminum hydride; formula _{(iC 4 H 9) x Al} y (C 5 H 10) z ( wherein, x, y, z are each a positive number, with z ≦ 2x Alkenyl aluminum alkoxide such as isobutylaluminum methoxide and isobutylaluminum ethoxide; Dialkylaluminum alkoxide such as dimethylaluminum methoxide, diethylaluminum ethoxide and dibutylaluminum butoxide; ethylaluminum sesquichloride ethoxide, butyl aluminum sesqui Bed alkylaluminum sesqui alkoxides such butoxide; general formula R ^a _2.5 Al partially alkoxy having an average composition represented by like (OR ^b) _0.5 Alkylaluminum; alkylaluminum aryloxides such as diethylaluminum phenoxide and diethylaluminum (2,6-di-t-butyl-4-methylphenoxide); dimethylaluminum chloride, diethylaluminum chloride, dibutylaluminum chloride, diethylaluminum bromide Dialkylaluminum halides such as diisobutylaluminum chloride; alkylaluminum sesquichlorides such as ethylaluminum sesquichloride, butylaluminum sesquichloride, ethylaluminum sesquibromide; partially halogenated alkyls such as alkylaluminum dihalides such as ethylaluminum dichloride Aluminum; diethylaluminum hydride, dibutylaluminum hydride Any partially alkylated aluminum such as dialkylaluminum hydride; alkylaluminum dihydride such as ethylaluminum dihydride, propylaluminum dihydride; moieties such as ethylaluminum ethoxychloride, butylaluminum butoxycyclide, ethylaluminum ethoxybromide Alkoxy aluminum which has been specifically alkoxylated and halogenated can be mentioned.

M ² AlR ^a ₄ … [VIII]
(In the formula [VIII], M ² represents Li, Na or K, and R ^a represents a hydrocarbon group having 1 to 15 carbon atoms, preferably 1 to 4 carbon atoms) Complex alkylated product of Group 1 metal and aluminum. Examples of such a compound include LiAl (C ₂ H ₅ ) ₄ and LiAl (C ₇ H ₁₅ ) ₄ .

In addition, a compound similar to the compound represented by the general formula [VII] can also be used.
For example, an organoaluminum compound in which two or more aluminum compounds are bonded through a nitrogen atom can be given. Specific examples of such a compound include (C ₂ H ₅ ) ₂ AlN (C ₂ H ₅ ) Al (C ₂ H ₅ ) ₂ .

From the viewpoint of availability, trimethylaluminum and triisobutylaluminum are preferably used as the (b-3) organoaluminum compound.
In the polymerization, the usage of each component and the order of addition are arbitrarily selected. For example, the catalyst component (A)
And a method of adding the catalyst component (B) to the polymerization vessel in any order.

In the above method, two or more of each catalyst component may be contacted in advance.
When the ethylene-based polymer of the present invention is produced by copolymerizing ethylene and an α-olefin having 4 to 10 carbon atoms using the olefin polymerization catalyst as described above, the catalyst component (A) The amount is usually 10 ⁻⁹ to 10 ⁻¹ mol, preferably 10 ⁻⁸ to 10 ⁻² mol per liter of volume.

Component (b-1) has a molar ratio [(b-1) / M] of component (b-1) to all transition metal atoms (M) in component (A) of usually 0.01 to 5,000, preferably Used in an amount of 0.05 to 2,000. Component (b-2) has a molar ratio [(b-2) / M] of the aluminum atoms in component (b-2) to all transition metals (M) in component (A), usually 10 to The amount used is 5,000, preferably 20 to 2,000. The component (b-3) has a molar ratio [(b-3) / M] of the component (b-3) and the transition metal atom (M) in the component (A) of usually 1 to 10,000, preferably Used in an amount of 1 to 5000.

In the high-temperature solution polymerization according to the present invention, the comonomer content is high and the composition distribution is narrow by copolymerizing ethylene and an α-olefin having 4 to 10 carbon atoms in the presence of the metallocene catalyst as described above. Thus, an ethylene polymer having a narrow molecular weight distribution can be efficiently produced. Here, the charged molar ratio of ethylene to the α-olefin having 4 to 10 carbon atoms is usually ethylene: α-olefin = 10: 90 to 99.9: 0.1, preferably ethylene: α-olefin = 30: 70 to 99.9. : 0.1, more preferably ethylene: α-olefin = 50: 50 to 99.9: 0.1.

Examples of the α-olefin having 4 to 10 carbon atoms include linear or branched α-olefins such as propylene, 1-butene, 2-butene, 1-pentene, 3-methyl-1-butene, 1-hexene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene and the like can be mentioned. The α-olefin that can be used in the high temperature solution polymerization of the present invention also includes polar group-containing olefins. Examples of polar group-containing olefins include α, β-unsaturated carboxylic acids such as acrylic acid, methacrylic acid, fumaric acid and maleic anhydride, and metal salts such as sodium salts thereof; methyl acrylate, ethyl acrylate, Α, β-unsaturated carboxylic acid esters such as n-propyl acrylate, methyl methacrylate and ethyl methacrylate; vinyl esters such as vinyl acetate and vinyl propionate; unsaturated glycidyl such as glycidyl acrylate and glycidyl methacrylate And the like. Vinylcyclohexane, diene or polyene; aromatic vinyl compounds such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, o, p-dimethylstyrene, methoxystyrene, vinylbenzoic acid, methyl vinylbenzoate Styrenes such as vinyl benzyl acetate, hydroxystyrene, p-chlorostyrene, divinylbenzene; and 3-phenylpropylene, 4-phenylpropylene, α-methylstyrene, etc. can coexist in the reaction system to promote high-temperature solution polymerization Is possible. Among the α-olefins described above, 1-butene, 1-hexene, 4-methyl-1-pentene and 1-octene are preferably used. In the high temperature solution polymerization method according to the present invention, cyclic olefins having 4 to 10 carbon atoms, preferably 3 to 20 carbon atoms such as cyclopentene, cycloheptene, norbornene, 5-methyl-2-
Norbornene or the like may be used in combination.

  “Solution polymerization” according to the present invention is a general term for methods in which polymerization is performed in a state where the polymer is dissolved in an inert hydrocarbon solvent described later at a temperature equal to or higher than the melting point of the polymer. In the solution polymerization according to the present invention, the polymerization temperature is usually 120 ° C to 300 ° C, preferably 130 ° C to 250 ° C, and more preferably 130 ° C to 200 ° C. "

In the high-temperature solution polymerization according to the present invention, when the polymerization temperature is less than 120 ° C., the polymerization activity is extremely lowered, so that it is not practical in terms of productivity. Further, in the polymerization temperature range of 120 ° C. or higher, as the temperature increases, the solution viscosity at the time of polymerization decreases, the heat of polymerization is easily removed, and the resulting olefin polymer can have a high molecular weight. However, when the polymerization temperature exceeds 300 ° C., the resulting polymer may be deteriorated, which is not preferable. In addition, from the viewpoint of the properties of the ethylene-based polymer that is preferably produced in the high-temperature solution polymerization according to the present invention, the ethylene described below, which is suitably used in many industrial fields such as a film in a region where the polymerization temperature is 120 to 200 ° C. It is possible to efficiently produce a polymer. The polymerization pressure is usually from normal pressure to 10 MPa gauge pressure, preferably from normal pressure to 8 MPa gauge pressure, and the polymerization reaction can be carried out in any of batch, semi-continuous and continuous methods. Furthermore, the polymerization can be carried out in two or more stages having different reaction conditions. The molecular weight of the resulting ethylene polymer can be adjusted by changing the hydrogen concentration in the polymerization system and the polymerization temperature within the scope of the present invention. Furthermore, it can also adjust with the quantity of the catalyst component (B) to be used. When hydrogen is added, the amount is suitably about 0.001 to 5,000 NL per 1 kg of the produced ethylene polymer.

The solvent used in the high temperature solution polymerization according to the present invention is usually an inert hydrocarbon solvent, preferably a saturated hydrocarbon having a boiling point of 50 ° C. to 200 ° C. under normal pressure. In particular,
Aliphatic hydrocarbons such as pentane, hexane, heptane, octane, decane, dodecane, and kerosene; and alicyclic hydrocarbons such as cyclopentane, cyclohexane, and methylcyclopentane. Aromatic hydrocarbons such as benzene, toluene and xylene, and halogenated hydrocarbons such as ethylene chloride, chlorobenzene and dichloromethane are also included in the category of “inert hydrocarbon solvents” related to the high-temperature solution polymerization of the present invention. There is no limit. As described above, in the high-temperature solution polymerization according to the present invention, MMAO that dissolves in aliphatic hydrocarbons and alicyclic hydrocarbons, as well as conventionally used aromatic hydrocarbon-soluble organoaluminum oxy compounds. A modified methylaluminoxane can be used. As a result, the use of aliphatic hydrocarbons and alicyclic hydrocarbons as solvents for solution polymerization almost completely eliminates the possibility of aromatic hydrocarbons being mixed into the polymerization system or the ethylene polymer produced. It became possible to do. That is, the high-temperature solution polymerization method according to the present invention has a feature that the environmental load can be reduced and the influence on human health can be minimized.

  In order to suppress variations in physical property values, it is preferable that the ethylene polymer particles obtained by the polymerization reaction and other components added as desired are melted by any method, kneaded, granulated, etc. .

<High-pressure low-density polyethylene>
The high-pressure method low-density polyethylene according to the present invention is a highly branched polyethylene having a long-chain branch produced by high-pressure radical polymerization.

As the high pressure method low density polyethylene, the NMR measured under the conditions of 190 ° C. and 2.16 kg load is usually in the range of 0.01 to 100 g / 10 min, preferably 0.1, in accordance with ASTM D1238-65T. It is in the range of ˜20 g / 10 minutes, and more preferably in the range of 1.0 to 15 g / 10 minutes.

Moreover, the high pressure method low density polyethylene has a density (D) of 0.910 to 0.930 g / cm ^3.
It is preferable that it exists in the range. The density (D) is measured with a density gradient tube after heat-treating the strand obtained at the time of MFR measurement at 190 ° C. under a load of 2.16 kg at 120 ° C. for 1 hour and gradually cooling to room temperature over 1 hour.

  The high-pressure low-density polyethylene uses a swell ratio representing the degree of long-chain branching, that is, a capillary flow characteristic tester, and is extruded at a rate of 10 mm / min from a nozzle having an inner diameter of 2.0 mm and a length of 15 mm under the condition of 190 ° C. It is desirable that the ratio of the diameter of the strand extruded in step 1 to the nozzle inner diameter (strand diameter / nozzle inner diameter) is 1.3 or more.

The high-pressure low-density polyethylene is a copolymer with ethylene in which a small amount of other polymerizable monomers such as other α-olefins, vinyl acetate, and acrylates are used within the range not impairing the object of the present invention. It may be.

<Resin composition>
The resin composition according to the present invention is a copolymer of the aforementioned ethylene and an α-olefin having 4 to 10 carbon atoms, and satisfies the following requirements (I) to (IV) simultaneously. It is characterized by containing 1% by weight and 40% by weight of high-pressure low-density polyethylene. (However, the total of the ethylene polymer and the high-pressure low-density polyethylene is 100% by weight.)
The resin composition preferably includes 70 to 90% by weight of an ethylene polymer and 10 to 30% by weight of a high pressure method low density polyethylene, and 75 to 85% by weight of an ethylene polymer and 15 to 25 high pressure method low density polyethylene. It is more preferable to contain the weight% (however, the total of the ethylene polymer and the high-pressure method low-density polyethylene is 100 weight%).

  Within the above range, a laminate having a layer formed from a composition comprising an ethylene polymer and a high-pressure low-density polyethylene is excellent in low-temperature heat sealing properties, hot tack properties, and high-speed liquid filling properties, and mechanical strength. Excellent.

  In addition to the above thermoplastic resin, the ethylene polymer according to the present invention further includes a weather resistance stabilizer, a heat resistance stabilizer, an antistatic agent, an anti-slip agent, and an anti-blocking agent as long as the object of the present invention is not impaired. Additives such as an antifogging agent, a lubricant, a pigment, a dye, a nucleating agent, a plasticizer, an anti-aging agent, a hydrochloric acid absorbent, and an antioxidant may be blended as necessary.

<Laminated body>
The laminate of the present invention is characterized by having a layer comprising the above-described resin composition.
That is, the laminate of the present invention is a copolymer of ethylene and an α-olefin having 4 to 10 carbon atoms, and 60 to 99% by weight of an ethylene polymer that simultaneously satisfies the above requirements (I) to (IV) and It includes a layer formed from a resin composition containing 1 to 40% by weight of high-pressure method low-density polyethylene (however, the total of the ethylene polymer and the high-pressure method low-density polyethylene is 100% by weight). It is a laminated body.

The laminate according to the present invention is a laminate including at least one layer composed of the resin composition, and the layer composed of the composition may be a single layer or a multilayer.
The layer structure of the laminate of the present invention is not particularly limited, but usually a two-layer structure of a base material / layer composed of the above resin composition, a base material 1 / a layer composed of the above resin composition / base material 2 Examples include a laminate having various layer configurations such as a three-layer configuration, a base material 1 / a layer composed of the above resin composition / a base material 2 / a four layer configuration composed of the above resin composition. Further, the substrate may be a substrate formed of a single layer or a substrate formed of multiple layers.

  As the layer structure of the laminate, it is preferable that the layer made of the resin composition forms at least one outermost layer. By forming the outermost layer with a layer made of the resin composition, the low-temperature heat sealability of the layer is exhibited.

As a form of the substrate used for the laminate of the present invention, a film or a sheet is preferable. The thickness of the film or sheet is usually 10 to 1,000 μm.
Examples of the material of the substrate include plastic, metal, glass, paper, and the like. The material for the substrate is preferably a plastic that can stably form a layer made of the resin composition, and the plastic is preferably a polyolefin polymer, an acrylic polymer, a polyester polymer, or the like.

When a plastic film is used as the substrate, the plastic film may be non-oriented or may be uniaxially or biaxially stretched.
Moreover, as such a base material, in order to form the layer which consists of the said resin composition stably, surface active treatments, such as a corona discharge process, may be given to the base-material surface, and an anchor coat layer is provided. Also good.

In addition, the layer made of the resin composition is preferably a sealing layer in order to exhibit the low temperature heat sealability.
When using the layer which consists of the said resin composition as a sealing layer, although the thickness of this sealing layer can be set suitably, Preferably it is about 5-100 micrometers. The seal layer made of the resin composition is excellent in heat seal strength and exhibits high heat seal strength even when the heat seal temperature is relatively low. That is, it is excellent in low temperature heat sealability.

The laminate according to the present invention can be produced, for example, by extrusion laminating the resin composition on the substrate.
When extruding and laminating the resin composition on the base material as described above, the resin composition may be extrusion laminated directly to the base material, and in order to increase the adhesive force between the base material and the resin composition. Alternatively, a known method, for example, an anchor coating agent may be applied to the base material in advance, or the resin composition may be extrusion-laminated after an undercoat resin layer such as adhesive polyolefin or high-pressure polyethylene is provided.

  The thickness of the layer composed of the resin composition at the time of extrusion lamination according to the present invention is not particularly limited, but is preferably 300 μm or less, more preferably 250 μm or less, from the viewpoint of maintaining transparency and flexibility. Preferably it is 200 micrometers or less. On the other hand, in consideration of mechanical properties and low-temperature heat sealability, the thickness of the layer is preferably 5 μm or more, more preferably 10 μm or more, and further preferably 15 μm or more.

Hereinafter, the example in the case of using the laminated body of this invention as a film for liquid packaging is shown.
When using the laminated body of this invention as a film for liquid packaging, the layer which consists of the said resin composition is used as a sealing layer of the film for liquid packaging. The thickness of the seal layer in this case can be set as appropriate, but is preferably about 5 to 100 μm.

  The configuration of the liquid packaging film is a configuration in which a sealing layer is formed on the base film and the base film, and the material for forming the base film is not particularly limited as long as it has film-forming ability. Any polymer or paper, aluminum foil, cellophane, etc. can be used.

Examples of such polymers include high density polyethylene, medium and low density polyethylene, ethylene / vinyl acetate copolymer, ethylene / acrylate copolymer, ionomer, polypropylene, poly-1-butene, and poly-4. -Olefin polymers such as methyl-1-pentene, vinyl polymers such as polyvinyl chloride, polyvinylidene chloride, polystyrene, polyacrylate, polyacrylonitrile, nylon 6, nylon 66, nylon 10, nylon 11, nylon 12, Polyamide polymers such as nylon 610 and polymetaxylylene adipamide, polyester polymers such as polyethylene terephthalate, polyethylene terephthalate / isophthalate, polybutylene terephthalate, polyvinyl alcohol, ethylene vinyl alcohol Copolymer, polycarbonate-based polymers and the like and mixtures thereof.

  Moreover, when a base film consists of a polymer, this polymer film may be non-oriented and may be extended | stretched uniaxially or biaxially. Further, the base film may be a single layer or a multilayer.

Such a liquid packaging film can be produced, for example, by performing the extrusion lamination described above.
The liquid packaging film can be cut into an appropriate size, and then superposed so that the sealant surfaces (layers made of the resin composition) are in contact with each other, and the surroundings are heat-sealed to form a liquid packaging container. Such a liquid packaging container is suitably used as a packaging container for products containing liquids such as various liquids such as liquid soup, liquid seasoning, juice, liquor, water, pickles and retort foods.

〔Example〕
The following present invention will be described in more detail with reference to examples, but the present invention is not limited thereto.

[Production of ethylene-based polymer-1]
One feed port of a 136 liter continuous polymerizer, dehydrated and purified n-hexane at a rate of 5.9 liters / hr, TMAO-341 (Tosoh Finechem) hexane slurry (5 mmol / liter as aluminum atoms) 0.3 liter / hr of di (p-tolyl) methylene (cyclopentadienyl) (octamethyloctahydrodibenzofluorenyl) zirconium dichloride in hexane (0.1 mmol / liter) at a rate of 0.03 liter / hr Then, a hexane solution (2 mmol / liter) of triisobutylaluminum was continuously supplied at a rate of 2.1 liter / hr (total hexane 8.3 liter / hr). At the same time, ethylene is supplied at a rate of 4.5 kg / hr and hydrogen at a rate of 40 liters / hr to another supply port of the continuous polymerization vessel, and 1-octene is supplied at a rate of 6.4 kg / hr to another supply port. Continuous solution polymerization was carried out under conditions of a polymerization temperature of 130 ° C., a total pressure of 2.8 MPa-G, a residence time of 65 min, and a stirring speed of 250 rpm.

The hexane solution of ethylene / 1-octene copolymer produced in the polymerization vessel is continuously discharged at a flow rate of 25.8 liter / hr through the discharge port provided in the side wall of the polymerization vessel, and the jacket portion is 8 kg / It was led to a connecting pipe heated with cm ² steam. A hexane solution of ethylene / 1-octene copolymer heated to about 170 ° C. in a connection pipe with a steam jacket was provided at the end of the connection pipe so as to maintain a solution volume of about 28 liters in the polymerization tank. By adjusting the opening of the liquid level control valve, the liquid was continuously fed to the flash tank through a double pipe inner tube heated with 10 kg / cm ² steam. Immediately after the liquid level control valve, a supply port for injecting methanol, which is a catalyst deactivator, is attached and injected as a 1.0 vol% hexane diluted solution at a rate of 12 liters / hr to join the hexane solution. I let you. In the transfer to the flash tank, the solution temperature and the pressure adjustment valve opening were set so that the pressure in the flash tank was 0.04 MPa-G and the temperature of the vapor part in the flash tank was maintained at 180 ° C.

As a result, an ethylene / 1-octene copolymer (1) was obtained at a production speed of 4.3 kg / hr. The MFR (190 ° C., 2.16 kg) of the obtained ethylene / 1-octene copolymer (1) was 12.5 g / 10 min, and the density was 883 kg / m ³ .

[Production of Ethylene Polymer-2]
One feed port of a 136 liter continuous polymerizer, dehydrated and purified n-hexane at a rate of 8.1 liter / hr, TMAO-341 (Tosoh Finechem) hexane slurry (5 mmol / liter as aluminum atoms) 0.2 liter / hr of di (p-tolyl) methylene (cyclopentadienyl) (octamethyloctahydrodibenzofluorenyl) zirconium dichloride in hexane (0.1 mmol / liter) at a rate of 0.02 liter / hr Then, a hexane solution (2 mmol / liter) of triisobutylaluminum was continuously supplied at a rate of 2.1 liter / hr (total hexane 10.4 liter / hr). At the same time, ethylene is supplied at a rate of 4.5 kg / hr and hydrogen is supplied at a rate of 30 liters / hr to another supply port of the continuous polymerization vessel.
Octene was continuously fed at a rate of 2.5 kg / hr, and continuous solution polymerization was performed under conditions of a polymerization temperature of 130 ° C., a total pressure of 3 MPa-G, a residence time of 70 min, and a stirring speed of 250 rpm.

The hexane solution of ethylene / 1-octene copolymer produced in the polymerization vessel is continuously discharged at a flow rate of 24 liter / hr through the discharge port provided on the side wall of the polymerization vessel, and the jacket portion is 8 kg / hr. It was led to a connecting pipe heated with cm ² steam. The hexane solution of ethylene / 1-octene copolymer heated to 170 ° C in the connection pipe with steam jacket is a liquid provided at the end of the connection pipe so as to maintain a solution volume of about 28 liters in the polymerization tank. By adjusting the opening of the level control valve, the liquid was continuously fed to the flash tank through a double pipe inner tube heated with 10 kg / cm ² steam. Immediately after the liquid level control valve, a supply port for injecting methanol, which is a catalyst deactivator, is attached and injected as a 1.0 vol% hexane diluted solution at a rate of 12 liters / hr to join the hexane solution. I let you. In the transfer into the flash tank, the solution temperature and the pressure adjustment valve opening were set so that the pressure in the flash tank was 0.04 MPa-G and the temperature of the vapor part in the flash tank was maintained at 180 ° C.

As a result, an ethylene / 1-octene copolymer (2) was obtained at a production speed of 4.5 kg / hr. MFR (190 ° C, 2.16 kg) of the obtained ethylene / 1-octene copolymer (2) is 5.6 g / 10 min.
The density was 899 kg / m ³ .

[Ethylene polymer-1C]
An ethylene / 4-methyl-1-pentene copolymer (trade name: Ultozex 15150J) commercially available from Prime Polymer was used. (Hereinafter also referred to as ethylene / 4MP-1 copolymer.)
[Physical properties of ethylene polymers]
The physical properties of the ethylene polymer were measured by the following methods [m1] to [m3].

Table 1 shows the physical properties of the ethylene polymer.
[m1] Ratio of weight average molecular weight to number average molecular weight (Mw / Mn)
The ratio (Mw / Mn) between the weight average molecular weight and the number average molecular weight of the ethylene-based polymer was measured as follows using GPC-150C manufactured by Waters. The separation columns are TSKgel GMH6-HT and TSKgel GMH6-HTL, the column size is 7.5 mm in inner diameter and 600 mm in length, the column temperature is 140 ° C., the mobile phase is o-dichlorobenzene (Wako Pure Chemical Industries, Ltd.) Industry) and 0.025 wt% BHT (Takeda Pharmaceutical) as an antioxidant, moved at 1.0 ml / min, and the sample concentration was 0.1 wt%,
The sample injection amount was 500 microliters, and a differential refractometer was used as a detector. For standard polystyrene, molecular weight Mw ≦ 1000 and Mw ≧ 4 × 10 ⁶ are manufactured by Tosoh Corporation, 1000 ≦ Mw
For ≦ 4 × 10 ⁶ , those manufactured by Pressure Chemical Co., Ltd. were used. The molecular weight calculation is a value calibrated to polyethylene after universal calibration.

[m2] Measurement of H / W First, an elution curve by temperature rising elution fractionation (TREF) was measured using a cross fractionation chromatograph CFCF-150A manufactured by Mitsubishi Oil Chemical Co., Ltd. as follows.

The measurement sample of ethylene polymer is solvent (o-dichlorobenzene) and the concentration is 4 mg.
/ Ml was dissolved at 140 ° C. and injected into the sample loop in the measuring apparatus.
The sample solution is injected into a TREF separation column (a stainless steel column attached with a device filled with glass beads as an inert carrier, the capacity is 0.88 ml, the pipe capacity is 0.07 ml).

Next, the sample solution was cooled from 140 ° C. to 0 ° C. at a rate of 1 ° C./min, and coated on an inert carrier. At this time, a polymer layer is formed on the surface of the inert carrier in the order of the high crystalline component to the low crystalline component. After the TREF separation column is held at 0 ° C. for another 30 minutes, 2 ml of the component dissolved at the temperature of 0 ° C. is transferred from the TREF separation column to the SEC separation column (Showex AT Shodex AT manufactured by Showa Denko KK) at a flow rate of 1 ml / min. -806MS x 3). While fractionation by molecular size is performed in the SEC separation column, the TREF separation column is heated to the next elution temperature (5 ° C) and held at that temperature for about 30 minutes. The elution temperature was raised stepwise at the following temperature.

[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, 102, 120, 140 ° C
The molecular weight of the components eluted at each temperature was measured, and the molecular weight of polyethylene was determined using a general calibration curve. The SEC temperature is 140 ° C and the data sampling time is 0.50 seconds. The sample solution that has passed through the SEC separation column is measured for absorbance in proportion to the polymer concentration with an infrared spectrophotometer (wavelength: 3.42 μm, 2924 cm ⁻¹ ), and chromatograms for each elution temperature section are obtained. Using the built-in data processing software, the base line of the chromatogram of each elution temperature segment obtained by the above measurement is drawn and processed. The area of each chromatogram is integrated and an integrated elution curve is calculated. In addition, the differential elution curve was calculated by differentiating the integral elution curve with temperature.

  Next, the resulting differential elution curve is plotted. The horizontal axis is the elution temperature of 89.3 mm per 100 ° C, the vertical axis is the differential amount (the total integrated elution amount is normalized to 1.0, and the change at 1 ° C is the differential amount. The value obtained by dividing the peak height (mm) of this differential elution curve by the width (mm) of 1/2 height was defined as H / W.

[m3] Measurement of η The intrinsic viscosity [[η] (dl / g)] was measured using a decalin solvent as follows. About 20 mg of an ethylene polymer was dissolved in 15 ml of decalin, and the specific viscosity η _sp was measured in an oil bath at 135 ° C. After adding 5 ml of decalin solvent to this decalin solution and diluting, the specific viscosity η _sp was measured in the same manner. This dilution operation was further repeated twice, and the value of η _sp / C when the concentration (C) was extrapolated to 0 was determined as the intrinsic viscosity. That is, the intrinsic viscosity [η] is represented by the following formula.

[η] = lim (η _sp / C) (C → 0)

65 mmφ of the obtained ethylene / 1-octene copolymer (1) and high-pressure low-density polyethylene
Using a single screw extruder (Placo Corporation), melt kneading at a set temperature of 180 ° C. and a screw speed of 50 rpm to obtain a resin composition (1) of 85% by weight to 15% by weight, and then extruding into a strand shape And pellets with a cutter.

  The pellet of the obtained resin composition (1) was placed on a substrate with a 65 mmφ extruder and a Sumitomo Heavy Industries Laminator having a T die with a die width of 500 mm. Under the conditions of 295 ° C. and a take-off speed of 80 m / min, extrusion lamination was performed so that the film thickness was 25 μm to form a laminate (1).

In all examples and comparative examples, a urethane anchor coating agent was applied to one side of a 15 μm thick biaxially stretched nylon film (trade name Emblem ONM, manufactured by Unitika Ltd.), and then Ziegler A base material composed of a multilayer obtained by extrusion-laminating an ethylene-based mixed resin obtained by blending 50 parts by weight of each of a linear low-density polyethylene obtained by a catalyst and a high-pressure method low-density polyethylene into a thickness of 25 μm was used.
In addition, the laminated body used the layer which consists of ethylene-type resin compositions as the sealing layer.

65 mmφ of the obtained ethylene / 1-octene copolymer (2) and high-pressure low-density polyethylene
Using a single screw extruder (Placo Corporation), melt kneading at a set temperature of 180 ° C. and a screw rotation speed of 50 rpm to obtain a resin composition (2) of 80% by weight to 20% by weight, and then extruding into a strand shape And pellets with a cutter.

  The pellet of the obtained resin composition (2) was placed on a base material using a 65 mmφ extruder and a Sumitomo Heavy Industries Laminator having a T die with a die width of 500 mm, and the resin temperature under the die was 130 mm. The laminate (2) was formed by extrusion lamination to a film thickness of 25 μm under the conditions of 295 ° C. and a take-off speed of 80 m / min.

[Comparative Example 1]
Using a 65 mmφ single-screw extruder (manufactured by Placo), melt melt-kneading Ultzex 15150J and high-pressure low-density polyethylene at a set temperature of 180 ° C. and a screw speed of 50 rpm.
After preparing a resin composition (1C) of 20% by weight to 20% by weight, the resin composition was extruded into a strand and pelletized with a cutter.

The pellet of the obtained resin composition (1C) was placed on a base material using a 65 mmφ extruder and a Sumitomo Heavy Industries laminator having a T die with a die width of 500 mm. The laminate (1C) was formed by extrusion lamination to a film thickness of 25 μm under the conditions of 295 ° C. and a take-off speed of 80 m / min.

[Physical properties of laminates]
The physical properties of the laminate were measured by the following methods [m4] to [m6].
[m4] Heat Seal Strength The resin composition layers of the obtained laminate were heat sealed under the following conditions, and the peel strength was measured.

The results are shown in Table 2.
・ Uses single-sided heating bar sealer ・ Heat seal pressure: 2 kg / cm ²
・ Heat seal time: 0.5 seconds ・ Width of seal bar: 10 mm
・ Specimen width: 15 mm
・ Peeling angle: 180 degrees ・ Peeling speed: 300 mm / min

[m5] Hot tack test Stacked film pieces of length 550mm x width 50mm, and sealed with a seal bar 10mm wide and 300mm long for 1 second at a pressure of 2.0kg / cm ² and at a specified temperature Then, simultaneously with the depressurization, a 45 g load was applied to each piece of film to forcibly peel the heat-sealed portion at a peel angle of 22.5 °, and the peel distance at each temperature was determined to provide an index for hot tack.

  The results are shown in Table 3.

[m6] The high-speed liquid filling property was evaluated under the conditions below the liquid filling speed .
The results are shown in Table 4.
Evaluation machine: Taisei Lamic NT-DANGAN TYPE-III
Preheat temperature: 80 ℃
Sealing temperature: 185 ° C / 160 ° C
Roll pressure: Vertical Left 80kPa / Right 60kPa Horizontal Left 390kPa / Right 370kPa
Bag size: 75mm x 85mm
Filling: water (23 ℃)
Filling amount: 240g / 10g (including bag weight)

Claims (2)

A copolymer of ethylene and an α-olefin having 4 to 10 carbon atoms, which satisfies the following requirements (I) to (IV) at the same time: 60 to 99% by weight, and high pressure method low density polyethylene 1 to 40 A laminate comprising a layer formed from a resin composition containing 100% by weight (provided that the total of the ethylene polymer and the high-pressure method low-density polyethylene is 100% by weight).
(I) The melt flow rate (MFR) at a load of 2.16 kg at 190 ° C. is in the range of 1.0 to 100 g / 10 min.
(II) The density (D) is in the range of 860 to 925 kg / m ³ .
(III) The ratio (Mw / Mn) between the weight average molecular weight and the number average molecular weight measured by GPC is in the range of 1.50 or more and 3.00 or less.
(IV) In the elution curve obtained by temperature rising elution fractionation (TREF), the peak height (H) with the strongest peak intensity and the width (W) at half the height of the strongest peak intensity The ratio (H / W) and density (D) satisfy the following relational expression (Eq-1) or (Eq-2) according to the MFR of requirement (I).
[When 1.0 ≦ MFR ≦ 10]
0.0163 × D-14.02 ≦ Log ₁₀ (H / W) ≦ 0.0163 × D-13.30
(Eq-1)
[When 10 <MFR ≦ 100]
0.0163 × D-14.10 ≦ Log ₁₀ (H / W) ≦ 0.0163 × D-13.40 (Eq-2) The laminate according to claim 1, wherein the ethylene polymer satisfies the following requirement (V).
(V) Intrinsic viscosity [[η] (dl / g)] measured in 135 ° C. decalin and MFR satisfy the following relational expression (Eq-3).
−0.21 × Log ₁₀ MFR + 0.16 ≦ Log ₁₀ [η] ≦ −0.21 × Log ₁₀ MFR + 0.31
... (Eq-3)