JP2017061654A - Polyethylene resin composition and inflation film and heavy substance packaging film made of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyethylene-based resin composition for a heavy-duty packaging bag film, which has excellent molding processing characteristics and an excellent balance between mechanical characteristics and rigidity. SOLUTION: The specific linear ethylene / α-olefin copolymer (A) is 31 to 99% by weight and (B-1) to (B-5) for forming a film having a film thickness of 60 μm or more. ). Ethylene / α-olefin copolymer (B) 1-69% by weight polyethylene-based resin composition. (B-1) MFRB = 0.1 g / 10 minutes to 10 g / 10 minutes (B-2) Density B = 0.895 to 0.940 g / cm3 (B-3) Measured by gel permeation chromatography (GPC) The minimum value (gc) of the molecular weight distribution [Mw / Mn] B of 3.0 to 5.5 (B-4) branching index g'between 100,000 and 1,000,000 is 0.40 to 0. (W2 + W3) measured by 85 (B-5) cross fractional chromatography (CFC) is greater than 40% by weight and less than 56% by weight [selection diagram] None

Description

  The present invention relates to a polyethylene resin composition having excellent molding process characteristics and excellent balance between mechanical properties and rigidity, and an inflation film and a heavy weight packaging film comprising the same, and more particularly, to molding process characteristics. The present invention relates to a polyethylene resin composition excellent in balance between heat seal strength, impact resistance and rigidity, and an inflation film and a heavy weight packaging bag film excellent in an appropriate automatic bag making machine.

  In conventional ethylene polymers that are widely used for packaging materials, there is a strong demand for further improvements in physical properties in addition to molding processability, which are suitable for any of various molding methods. The melt flow characteristics governing moldability are broadly divided into extrudability related to the molten resin pressure under shear stress and molding stability related to melt elasticity during elongation deformation. Low viscosity is obtained under high shear stress, bubbles are stable under high speed molding of inflation molding, and necking-in of extrusion laminate molding T-die is small. It is very difficult to satisfy all of these requirements.

  Conventionally, so-called linear low density polyethylene (LLDPE or metallocene PE) has a linear molecular structure and is known to have superior strength compared to conventional high pressure polyethylene having many branched branches. However, in general, the molding process of the polyethylene resin is carried out in a molten state. However, when the film thickness is about 50-200 μm to be produced, it is necessary to increase the amount of resin extrusion per unit time. In the case of LLDPE and metallocene PE, the melt characteristics are insufficient in terms of fluidity and the extensional viscosity is insufficient, and it is difficult to sufficiently secure the moldability.

As countermeasures to compensate for these problems, melt properties and solid physical properties have been improved by blending high-pressure polyethylene with excellent moldability and blending ethylene polymers with different molecular weights and densities ( For example, see Patent Documents 1 to 3)
However, these blends (ethylene-based resin compositions) have a problem in that, although molding processability is obtained, impact strength is reduced due to blending of high-pressure polyethylene.

In addition, in order to make heavy-weight packaging bags at a high speed using an automatic bag-making machine, it is necessary to increase the waist (stiffness) of the film, but if the waist (stiffness) of the film is increased, the impact strength In order to improve the balance between film stiffness and impact strength, for example, the combination of two types of specific ethylene / α-olefin copolymers with different densities has been further improved. Attempts have been made to use ternary blend compositions to which specific high-pressure polyethylene has been added (see, for example, Patent Document 4).
According to this method, although a polyethylene resin composition having an excellent balance between impact strength and rigidity and excellent molding processing characteristics can be obtained conventionally, a decrease in impact strength due to blending of high-pressure polyethylene is inevitable, Furthermore, the blend of the three types of ethylene polymers is considered to be economically disadvantageous as compared with the conventional method in order to stably supply a product of a constant quality at an industrial level.
As described above, in the conventional technique, it is difficult to sufficiently satisfy the basic performance required as a film for a packaging bag.

  In recent years, an ethylene-based polymer for modifying polyolefin-based resins to improve molding processability and resin strength at the same time by utilizing polymerization design technology using a metallocene catalyst capable of forming a long-chain branched structure in an ethylene-based polymer Development has been reported. For example, an ethylene polymer containing a long chain branch that expresses a specific elongational viscosity behavior is blended with a polyolefin resin to be used as a modifier for a polyolefin resin (see Patent Document 5). Examples of resin compositions using a low-density ethylene / propylene copolymer having a long-chain branched structure defined by a polymer molecular structure index and an intrinsic viscosity ratio as a modifier (see Patent Document 6), and high flow activation An example in which a long-chain branched polyethylene having a broad molecular weight distribution showing energy is used as a modifier (see Patent Document 7) is known. According to these methods, the impact strength of the polyolefin resin is not significantly reduced as is caused by the modification by the conventional HPLD, but the long chain branching-containing ethylene polymer is not sufficiently designed, so a high forming process However, it is still insufficient as a resin constituting a resin composition for heavy-duty packaging bags that require properties, rigidity, impact resistance and heat seal strength.

  Under these circumstances, a polyethylene-based resin that eliminates the problems of conventional ethylene-based resin compositions, is capable of producing molded products with excellent molding processability and excellent balance between impact strength and rigidity and transparency. The development of a film was desired.

  Under these circumstances, the ethylene-based polymer for reforming which has solved the problems of the conventional ethylene-based polymer for reforming, is excellent in forming processability, and has excellent balance of impact strength and rigidity and transparency is also provided. Research on metallocene polymerization catalysts capable of controlling a long-chain branched structure useful for the development of coalescence and further for the development of ethylene polymers having these characteristics has been continued (see Patent Documents 8 to 11).

Japanese Patent Application Laid-Open No. 7-149962 JP 2006-312753 A JP-A-9-31260 JP 2010-31270 A JP 2012-214781 A JP 09-031260 A JP 2007-119716 A JP 2004-217924 A Japanese Patent Laid-Open No. 2004-292772 JP 2005-206777 A JP 2013-227271 A

  In view of the above-mentioned problems of the prior art, the object of the present invention is a polyethylene resin composition having excellent melt tension necessary for molding processability, as well as an inflation suitable for an automatic bag making machine, An object of the present invention is to provide a film for a heavyweight packaging bag and a film for a heavy weight packaging bag in which the impact resistance is improved and at the same time the impact resistance, rigidity and heat seal strength are balanced.

  As a result of further research to solve the above problems, the present inventors have found that an ethylene polymer having a specific physical property, that is, a specific long-chain branching index and a relatively narrow inverse comonomer composition distribution index. In addition, in a resin composition using a novel ethylene polymer having a specific MFR, density, and molecular weight distribution, the impact strength, rigidity and heat are further superior to those of a resin composition using a conventionally known polymer. The present inventors have found that a resin composition showing a balance in seal strength and a heavy-weight packaging film can be obtained, leading to the present invention.

That is, 1st invention of this application is a polyethylene-type resin composition for film shaping | molding whose film thickness is 60 micrometers or more, Comprising: One or more types which satisfy the following conditions (A-1)-conditions (A-3) The ethylene / α-olefin copolymer (B) satisfying the following conditions (B-1) to (B-5): 1) to 69% by weight, and the whole composition satisfies the conditions (C-1) to (C-2).
Conditions for ethylene / α-olefin copolymer (A);
(A-1) MFR _A = 0.1 to 10 g / 10 min (A-2) Density _A = 0.900 to 0.960 g / cm ³
(A-3) Molecular weight distribution [Mw / Mn] measured by gel permeation chromatography (GPC) _A is 2.0 to 10.0.
Conditions for the ethylene polymer (B);
(B-1) MFR _B = 0.1 g / 10 min to 10 g / 10 min (B-2) Density _B = 0.895 to 0.940 g / cm ³
(B-3) Molecular weight distribution [Mw / Mn] measured by gel permeation chromatography (GPC) _B is 3.0 to 5.5 (B-4) Differential refractometer, viscosity detector and light scattering The minimum value (gc) of the branching index g ′ measured by a GPC measuring apparatus combined with a detector between 100,000 and 1,000,000 is 0.40 to 0.85 (B-5) Cross fractionation chromatography From the component (W ₂ ) of which the molecular weight is equal to or higher than the weight average molecular weight among the components eluted at or below the temperature at which the elution amount determined from the integrated elution curve measured by chromatography (CFC) is 50 wt%, and the integrated elution curve The sum (W ₂ + W ₃ ) of the proportions (W ₃ ) of the components whose molecular weight is less than the weight average molecular weight out of the components eluted at a temperature higher than the temperature at which the obtained elution amount is 50 wt% is 40% by weight. And less than 56% by weight
Overall composition conditions;
(C-1) MFR = 0.1 to 10 g / 10 min (C-2) Density = 0.910 to 0.950 g / cm ³

The second invention of the present application is the polyethylene resin composition according to the first invention, wherein the ethylene / α-olefin copolymer (B) further satisfies the following condition (B-6): Exist.
(B-6) Ratio of components having a molecular weight equal to or higher than the weight average molecular weight among the components eluted at a temperature higher than the temperature at which the elution amount obtained from the integral elution curve measured by W ₂ and CFC is 50 wt% (W ₄ ) Sum (W ₂ + W ₄ ) is more than 25 wt% and less than 50 wt%

According to a third invention of the present application, the ethylene / α-olefin copolymer (B) satisfies the following condition (B-7), and the polyethylene resin according to the first or second invention Present in the composition.
(B-7) The difference between W ₂ and W ₄ (W ₂ −W ₄ ) is more than 0% by weight and less than 20% by weight.

According to a fourth aspect of the present invention, in the first aspect, the ethylene / α-olefin copolymer (B) further satisfies the following condition (B-8): It exists in a polyethylene-type resin composition.
(B-8) The ratio (X) of the component that elutes at 85 ° C. or higher by temperature rising elution fractionation (TREF) is 2 to 15% by weight.

  According to a fifth aspect of the present invention, the α-olefin of the ethylene / α-olefin copolymer (B) has 3 to 10 carbon atoms, and is described in any one of the first to fourth aspects. Present in the polyethylene-based resin composition.

The sixth invention of the present application is characterized in that a polymer satisfying the following conditions is used as the ethylene / α-olefin copolymer (A) and the ethylene / α-olefin copolymer (B). It exists in the polyethylene-type resin composition as described in any one of -5.
(AB-1) MFR _A > MFR _B
(AB-2) Density _A > Density _B
(AB-3) [Mw / Mn] _A <[Mw / Mn] _B

  7th invention of this application exists in the heavy weight packaging bag film which consists of a resin composition as described in any one of 1st-6th invention.

  The polyethylene resin composition of the present invention satisfies the melt tension required for molding processability, maintains heat seal strength, and further has excellent impact resistance (dirt drop impact strength), impact resistance, rigidity (tensile modulus) ) And heat seal strength. In addition, the inflation film and heavy weight packaging bag film of the present invention are excellent in suitability for automatic bag making machines, and in particular, excellent in blow molding characteristics when producing heavy weight packaging bags.

It is a graph which shows the base line and area of a chromatogram used by gel permeation chromatography (GPC) method. It is a graph which shows the relationship between the branch index (g ') computed from GPC-VIS measurement (branch structure analysis), and molecular weight (M). It is a graph which shows elution temperature distribution by temperature rising elution fractionation (TREF). It is the graph which showed the relationship between the melt tension and dart drop impact in a present-application Example and a comparative example. It is the graph which showed the relationship between the seal strength and dart drop impact in an example of the present application and a comparative example. It is a schematic view of W ₁ to _W-4. Here, the horizontal axis represents the logarithm of molecular weight (log M), and the vertical axis represents the elution temperature (Temp.).

  The present invention has a specific linear ethylene / α-olefin copolymer (A), a specific long chain branching index, a relatively narrow inverse comonomer composition distribution index, and a specific MFR, density and molecular weight. The present invention relates to a polyethylene resin composition containing a good ethylene / α-olefin copolymer (B) as an olefin resin modifier having a distribution. Hereinafter, the present invention will be described in detail for each item.

1. Linear ethylene / α-olefin copolymer of the present invention (A)
The linear ethylene / α-olefin copolymer (A) used in the present invention has a low-density ethylene obtained by copolymerizing ethylene and an α-olefin, having a long chain branching structure and a linear molecular structure. An α-olefin copolymer, such as LLDPE (linear low density polyethylene) obtained by a Ziegler catalyst or a linear low density polyethylene called metallocene PE obtained by a metallocene catalyst. In addition, such a linear low-density polyethylene that does not substantially have a long-chain branched structure and has a linear molecular structure usually has a gc value of 0.85 as defined in the present invention. Since it exceeds the value, it is different from the ethylene / α-olefin copolymer (B) described later. Among them, the linear ethylene / α-olefin copolymer (A) composed of one or more of the present invention satisfies the conditions (1) to (3) described below.

1-1. Condition (1) MFR
The melt flow rate (MFR) of the linear ethylene / α-olefin copolymer comprising one or more of the present invention is 0.1 g / 10 min or more and 10 g / 10 min or less, preferably 0.1 g / 10 min. More than 5 g / 10 minutes, more preferably more than 0.1 g / 10 minutes and not more than 2.0 g / 10 minutes. When the MFR is within this range, the effect of improving moldability when blended with a polyolefin resin and the effect of improving the balance between impact strength and rigidity are excellent. On the other hand, if the MFR is 0.1 g / 10 min or less, there are cases where it is not preferable in terms of molding processability and the like, and if the MFR is greater than 10 g / 10 min, it is not preferable because the effect of improving the impact strength and rigidity is hardly exhibited. . In the present invention, the MFR of the ethylene / α-olefin copolymer conforms to “Testing method of melt mass flow rate (MFR) and melt volume flow rate (MVR) of plastic-thermoplastic plastic” of JIS K7210. , 190 ° C., 21.18N (2.16 kg) when measured under load conditions.

1-2. Condition (2) Density Density of the linear ethylene · alpha-olefin copolymer comprising one or more of the present invention is a 0.900~0.960g / cm ^3, preferably 0.910 g / cm ³ or more , less than 0.950 g / cm ^3, more preferably 0.915 to 0.940 g / cm ^3, more preferably from 0.920~0.935g / cm ^3.
When the density is in this range, the effect of improving the balance between impact strength and rigidity when blended with a polyethylene resin to be modified is excellent. On the other hand, if the density is less than 0.900 g / cm ³ , it may not be preferable in terms of rigidity, and if the density is more than 0.960 g / cm ^{3, the} effect of improving impact strength and the like is not sufficient, which is not preferable.
In the present invention, the density of the ethylene / α-olefin copolymer is a value measured by the following method.

  The pellets were hot-pressed to prepare a press sheet having a thickness of 2 mm. The sheet was placed in a beaker having a capacity of 1000 ml, filled with distilled water, capped with a watch glass, and heated with a mantle heater. After boiling boiling water for 60 minutes, the beaker was placed on a wooden table and allowed to cool. At this time, the boiling distilled water after boiling for 60 minutes was adjusted to 500 ml so that the time until reaching room temperature was not less than 60 minutes. Moreover, the test sheet was immersed in the substantially center part in water so that it might not contact a beaker and the water surface. After annealing the sheet at a temperature of 23 ° C. and a humidity of 50% for 16 hours to 24 hours, the sheet is punched out to 2 mm in length and width, and tested at 23 ° C., JIS K7112 “Plastic-non-foamed plastic density And a specific gravity measurement method ”.

1-3. Condition (3) Molecular Weight Distribution The ratio (Mw / Mn) of the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the linear ethylene / α-olefin copolymer (A) comprising one or more types in the present invention is 2.0 to 10.0, preferably 2.0 to 8.0, more preferably 2.0 to less than 7.0, still more preferably 3.0 to less than 6.0. If Mw / Mn is less than 2.0, it should be avoided because it is inferior in molding processability when blended with a polyolefin-based resin, in particular, melt flowability, or is difficult to mix with other polymer components. If Mw / Mn is greater than 10.0, the effect of improving the rigidity and impact strength of the polyolefin resin and the molded product thereof becomes insufficient, transparency is deteriorated, and stickiness tends to occur.
Mw / Mn is one of the indices indicating the molecular weight distribution in the copolymer. The value is small when the polymerization reaction on the catalyst is carried out at a relatively uniform site, and is carried out at a relatively multi-site. And the number increases. By selecting the catalyst type used for the polymerization and the conditions for adjusting the catalyst, it can be roughly controlled as appropriate.
In the present invention, Mw and Mn of the ethylene / α-olefin copolymer are those measured by gel permeation chromatography (GPC).

Conversion from the retention volume to the molecular weight is performed using a calibration curve prepared in advance with standard polystyrene. The standard polystyrenes used are all the following brands manufactured by Tosoh Corporation.
F380, F288, F128, F80, F40, F20, F10, F4, F1, A5000, A2500, A1000.
A calibration curve is generated by injecting 0.2 mL of a solution dissolved in ODCB (containing 0.5 mg / mL BHT) so that each is 0.5 mg / mL. The calibration curve uses a cubic equation obtained by approximation by the least square method. Conversion to molecular weight uses a general-purpose calibration curve with reference to “Size Exclusion Chromatography” written by Sadao Mori (Kyoritsu Shuppan). The following numerical value is used for the viscosity formula [η] = K × M ^α used in this case.
PS: K = 1.38 × 10 ⁻⁴ , α = 0.7
PE: K = 3.92 × 10 ⁻⁴ , α = 0.733
The measurement conditions for GPC are as follows.
Apparatus: Waters GPC (ALC / GPC 150C)
Detector: MIRAN 1A IR detector manufactured by FOXBORO (measurement wavelength: 3.42 μm)
Column: AD806M / S (3 pieces) manufactured by Showa Denko KK
Mobile phase solvent: o-dichlorobenzene Measurement temperature: 140 ° C.
Flow rate: 1.0 ml / min Injection volume: 0.2 ml
Sample preparation: Prepare a 1 mg / mL solution using ODCB (containing 0.5 mg / mL BHT) and dissolve it at 140 ° C. for about 1 hour.
The baseline and section of the obtained chromatogram are performed as illustrated in FIG.

1-4. Composition of ethylene / α-olefin copolymer (A) The ethylene / α-olefin copolymer (A) component is a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms.
The ratio of ethylene and α-olefin in the ethylene / α-olefin copolymer (A) is about 80 to 100% by weight of ethylene and about 0 to 20% by weight of α-olefin, preferably about 85 to 99. 9 wt%, α-olefin about 0.1 to 15 wt%, more preferably ethylene about 90 to 99.5 wt%, α-olefin about 0.5 to 10 wt%, and still more preferably about ethylene 90 to 99% by weight, α-olefin about 1 to 10% by weight. When the ethylene content is within this range, the balance between the rigidity and impact strength of the polyethylene resin composition and the molded article is good.

1-5. Production method of ethylene / α-olefin copolymer (A) The ethylene / α-olefin copolymer (A) is produced by homopolymerizing ethylene or copolymerizing with the above-mentioned α-olefin using an olefin polymerization catalyst. Is done.
Various types of catalysts for olefin polymerization are known today, and the ethylene / α-olefin copolymer (A) is within the scope of the constitution of the catalyst component and the contrivance of polymerization conditions and post-treatment conditions. Although it will not be restrict | limited as long as it can prepare, As a technical example suitable for manufacture of an ethylene-alpha-olefin copolymer (A) and satisfying economical efficiency in an industrial level, the following (i)-( Specific examples of the olefin polymerization catalyst containing the transition metal described in ii) can be given.

(I) Ziegler catalyst As an example of an olefin polymerization catalyst suitable for the production of an ethylene / α-olefin copolymer (A), an olefin coordination polymerization catalyst comprising a combination of a transition metal compound and an alkyl compound of a typical metal. Ziegler-Natta catalyst. In particular, a so-called Mg-Ti Ziegler catalyst in which a solid catalyst component in which a titanium compound is supported on a magnesium compound and an organoaluminum compound are combined (for example, “Catalog of Catalysis Utilization; 2004 Industrial Research Committee”, “Application System Diagram—Olefin” The transition of the polymerization catalyst--see “Issued by the Invention Association in 1995” etc.) is preferable because it is inexpensive, highly active and excellent in the polymerization process.
(Ii) Metallocene catalyst As an example of a polymerization catalyst suitable for the production of the ethylene / α-olefin copolymer (A), a metallocene catalyst (for example, “metallocene”) which is an olefin polymerization catalyst comprising a metallocene transition metal compound and a promoter component. Next-generation polymer industrialization technology using catalysts (1st and 2nd volume; published in 1994 by Inter Research Co., Ltd.)) is relatively inexpensive, highly active, excellent in polymerization process, and has a molecular weight distribution and copolymer composition distribution. Is used because an ethylene polymer having a narrow width is obtained.

2. Ethylene / α-olefin copolymer (B) of the present invention
The ethylene / α-olefin copolymer (B) of the present invention satisfies the conditions (1) to (5) described below, preferably further satisfies the conditions (6) and / or (7) and (8).

2-1. Condition (1) MFR
The melt flow rate (MFR) of the ethylene / α-olefin copolymer (B) of the present invention is more than 0.1 g / 10 min, 10 g / 10 min or less, preferably more than 0.1 g / 10 min. 0.0 g / 10 min or less, more preferably more than 0.1 g / 10 min and 2.0 g / 10 min or less.

  When the MFR is within this range, the effect of improving moldability when blended with a polyethylene resin and the effect of improving the balance between impact strength and rigidity are excellent. On the other hand, if the MFR is 0.1 g / 10 min or less, there are cases where it is not preferable in terms of molding processability and the like, and if the MFR is greater than 10 g / 10 min, it is not preferable because the effect of improving the impact strength and rigidity is hardly exhibited. . In the present invention, the MFR of the ethylene / α-olefin copolymer is in accordance with JIS K7210 “Testing method of melt mass flow rate (MFR) and melt volume flow rate (MVR) of plastic-thermoplastic plastic”. , 190 ° C., 21.18N (2.16 kg) when measured under load conditions.

2-2. Condition (2) Density The density of the ethylene / α-olefin copolymer (B) of the present invention is 0.895 to 0.940 g / cm ³ , preferably 0.898 g / cm ³ or more and 0.934 g / cm ^3. less than ^3, more preferably 0.900~0.930g / cm ^3, more preferably 0.905~0.930g / cm ^3, particularly preferably 0.910~0.925g / cm ^3.
When the density is in this range, the effect of improving the balance between impact strength and rigidity when blended with a polyethylene resin to be modified is excellent. On the other hand, if the density is less than 0.895 g / cm ³ , it may not be preferable in terms of rigidity, and if the density is more than 0.940 g / cm ³ , the improvement effect such as impact strength is not sufficient, which is not preferable.
In the present invention, the density of the ethylene / α-olefin copolymer (B) is a value measured by the same method as that for the copolymer (A).

2-3. Condition (3) Molecular Weight Distribution The ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the ethylene / α-olefin copolymer (B) in the present invention is 3.0 to 5.5. Preferably, it is 3.0-5.3, More preferably, it is 3.3 or more and less than 5.3, More preferably, it is 3.5 or more and less than 5.3. If Mw / Mn is less than 3.0, molding processability when blended with a polyolefin resin, particularly melt flowability is inferior, and it is difficult to mix with other polymer components. If Mw / Mn is greater than 5.5, the effect of improving the rigidity and impact strength of the polyolefin resin and the molded product thereof is insufficient, transparency is deteriorated, and stickiness tends to occur.

  Mw / Mn is one of the indices indicating the molecular weight distribution in the copolymer. The value is small when the polymerization reaction on the catalyst is carried out at a relatively uniform site, and is carried out at a relatively multi-site. And the number increases. By selecting the catalyst type used for the polymerization and the conditions for adjusting the catalyst, it can be roughly controlled as appropriate.

  In the present invention, Mw and Mn of the ethylene / α-olefin copolymer (B) are those measured by the gel permeation chromatography (GPC) method.

2-4. Condition (4) gc
The ethylene / α-olefin copolymer (B) in the present invention is measured by a GPC measurement device that combines a differential refractometer, a viscosity detector, and a light scattering detector in addition to the above conditions (1) to (3). The lowest value (gc) of the branching index g ′ having a molecular weight between 100,000 and 1,000,000 is 0.40 to 0.85, preferably 0.45 to 0.85 or 0.50 to 0.85, More preferably, it is 0.50-0.77, Most preferably, it is 0.51-0.75. If the g _C value is greater than 0.85, the effect of improving the moldability when blended with a polyolefin resin is not sufficiently exhibited, which is not preferable. When the g _C value is less than 0.40, the moldability of the polyolefin resin is improved, but the impact strength is lowered and the transparency is deteriorated, which is not preferable.

In the present invention, the g _C value of the ethylene / α-olefin copolymer (B) is a physical property value indicating the degree of development of long chain branching introduced into the copolymer, and the g _C value is large. indicates that long chain branching is small, the introduction of long chain branching and g _C value is small in many cases. The value of g _C can be roughly controlled by selecting a catalyst used for polymerization. The g _C value of the ethylene / α-olefin copolymer is a method for evaluating the amount of long-chain branching using a molecular weight distribution curve or branching index (g ′) calculated from the following GPC-VIS measurement.

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

References:
1. Developments in polymer characterization, vol. 4). Essex: Applied Science; 1984. Chapter 1.
2. Polymer, 45, 6495-6505 (2004).
3. Macromolecules, 33, 2424-2436 (2000).
4). Macromolecules, 33, 6945-6925 (2000).

[Calculation of branching index (g _C ), etc.]
The branching index (g ′) is calculated as a ratio (ηbranch / ηlin) between the intrinsic viscosity (ηbranch) obtained by measuring the sample with the above Viscometer and the intrinsic viscosity (ηlin) obtained separately by measuring a linear polymer. To do.

When long chain branching is introduced into a polymer molecule, the radius of inertia is reduced compared to a linear polymer molecule of the same molecular weight. Since the intrinsic viscosity decreases as the radius of inertia decreases, the ratio of the intrinsic viscosity (ηbranch) of the branched polymer to the intrinsic viscosity (ηlin) of the linear polymer having the same molecular weight decreases as the long chain branching is introduced (ηbranch / ηlin). It will become. Therefore, when the branching index (g ′ = ηbranch / ηlin) is smaller than 1, it means that a branch is introduced, and the introduced long chain branching increases as the value decreases. Means that. In particular, in the present invention, as the absolute molecular weight obtained from MALLS, the minimum value of the above g ′ at a molecular weight of 100,000 to 1,000,000 is calculated as g _C. FIG. 2 shows an example of the analysis result by the GPC-VIS. The left side of FIG. 2 shows the molecular weight distribution curve measured based on the molecular weight (M) obtained from MALLS and the concentration obtained from RI, and the right side of FIG. 2 shows the branching index (g ′) at the molecular weight (M). . Here, linear polyethylene Standard Reference Material 1475a (National Institute of Standards & Technology) was used as the linear polymer.

2-5. Condition (5) W ₂ + W ₃
In addition to the above conditions (1) to (4), the ethylene / α-olefin copolymer (B) in the present invention is further eluted from an integral elution curve measured by cross fractionation chromatography (CFC). That elute at a temperature higher than the temperature at which the elution amount obtained from the integral elution curve is 50% by weight (W ₂ ) of the component eluting at a temperature equal to or less than 50 wt% Of these, the sum (W ₂ + W ₃ ) of the proportion (W ₃ ) of components having a molecular weight less than the weight average molecular weight is more than 40% by weight and less than 56% by weight. Preferably it is more than 41 wt%, less than 56 wt%, more preferably more than 43 wt%, less than 56 wt%, particularly preferably more than 45 wt% and less than 56 wt%.
The above numerical values such as W1 obtained from the integral elution curve measured by cross-fractionation chromatography (CFC) collectively indicate the distribution of comonomer amount and molecular weight of each polymer contained in the entire copolymer. This is a technique used to show “comonomer composition distribution”. That is, a polymer having a large amount of comonomer and a small molecular weight (W ₁ ), a polymer having a large amount of comonomer and a large molecular weight (W ₂ ), a polymer having a small amount of comonomer and a small molecular weight (W ₃ ), and a molecular weight having a small amount of comonomer The ratio of the polymer (W ₄ ) having a large value in the entire copolymer is shown. FIG. 6 shows a schematic diagram of W _{1 to} W ₄ .

If the W ₂ + W ₃ value is too small, the proportion of the low density high molecular weight component that effectively acts to improve the impact strength of the polyolefin resin contained in the ethylene / α-olefin copolymer (B) may be reduced, High density and low density components that effectively improve the rigidity of polyolefin resins are reduced, and a larger amount of ethylene / α-olefin copolymer blend is required to bring about an effect of improving physical properties. It is not desirable because it is not intended. On the other hand, if the W ₂ + W ₃ value is too large, the balance between the content of the high density low molecular weight component and the content of the low density high molecular weight component contained in the ethylene / α-olefin copolymer is lost, and the physical properties of the polyolefin resin are improved. The quality effect does not appear as expected, or the dispersibility of the high-density low-molecular weight component and the low-density high-molecular weight component deteriorates, resulting in deterioration of transparency and generation of a gel.

[CFC measurement conditions]
Cross fractionation chromatography (CFC) consists of a temperature rising elution fractionation (TREF) part for performing crystalline fractionation and a gel permeation chromatography (GPC) part for molecular weight fractionation.

The analysis using the CFC is performed as follows.
First, a polymer sample was completely dissolved in orthodichlorobenzene (ODCB) containing 0.5 mg / mL BHT at 140 ° C., and this solution was passed through a sample loop of the apparatus, and a TREF column (inert) maintained at 140 ° C. The polymer sample is crystallized by slowly cooling to a predetermined first elution temperature. After maintaining at a predetermined temperature for 30 minutes, ODCB is passed through a TREF column, whereby the eluted component is injected into the GPC section to perform molecular weight fractionation, and an infrared detector (MIRAN 1A IR detector manufactured by FOXBORO, A chromatogram is obtained with a measurement wavelength of 3.42 μm. Meanwhile, in the TREF part, the temperature is raised to the next elution temperature, and after obtaining the chromatogram of the first elution temperature, the elution component at the second elution temperature is injected into the GPC part. Hereinafter, by repeating the same operation, a chromatogram of the eluted components at each elution temperature is obtained.

The CFC measurement conditions are as follows.
Equipment: CFC-T102L manufactured by Dia Instruments
GPC column: Showa Denko AD-806MS (3 connected in series)
Solvent: ODCB
Sample concentration: 3 mg / mL
Injection volume: 0.4mL
Crystallization rate: 1 ° C / min Solvent flow rate: 1 mL / min GPC measurement time: 34 minutes Stabilization time after GPC measurement: 5 minutes Elution temperature: 0, 5, 10, 15, 20, 25, 30, 35, 40, 45 49, 52, 55, 58, 61, 64, 67, 70, 73, 76, 79, 82, 85, 88, 91, 94, 97, 100, 102, 120, 140

[Data analysis]
From the chromatogram of the eluted components at each elution temperature obtained by the measurement, the eluted amount (proportional to the area of the chromatogram) normalized so that the sum is 100% is obtained.
In addition, an integrated elution curve for the elution temperature is calculated. The integrated elution curve is differentiated with temperature to obtain a differential elution curve.
Moreover, molecular weight distribution is calculated | required by the following procedure from each chromatogram. Conversion from the retention volume to the molecular weight is performed using a calibration curve prepared in advance with standard polystyrene. The standard polystyrenes used are the following brands manufactured by Tosoh Corporation.
F380, F288, F128, F80, F40, F20, F10, F4, F1, A5000, A2500, A1000.

A calibration curve is created by injecting 0.4 mL of a solution dissolved in ODCB (containing 0.5 mg / mL BHT) so that each is 0.5 mg / mL.
The calibration curve uses a cubic equation obtained by approximation by the least square method.
Conversion to molecular weight uses a general-purpose calibration curve with reference to “Size Exclusion Chromatography” written by Sadao Mori (Kyoritsu Shuppan). The following numerical value is used for the viscosity formula [η] = K × M ^α used in this case.
PS: K = 1.38 × 10 ⁻⁴ , α = 0.7
PE: K = 3.92 × 10 ⁻⁴ , α = 0.733
In the chromatogram at the first elution temperature, the peak due to BHT added to the solvent may overlap with the low molecular weight side of the elution component. In this case, the baseline is drawn as shown in FIG. Define the desired section.
Further, as shown in Table 1 below, the weight average molecular weight of the whole (whole) is obtained from the elution ratio (wt% in the table) and the weight average molecular weight (Mw in the table) at each elution temperature.

  In addition, from the molecular weight distribution and elution amount at each elution temperature, literature (S. Nakano, Y. Goto, “Development of Automatic Cross Fractionation: Combination of Crystallization Fractionation and Molecule Fractionation. .26, pp. 4217-4231 (1981)), a graph (contour map) is obtained which shows the elution amount related to the elution temperature and molecular weight as contour lines.

The following component amounts are determined using the above contour map.
W ₁ : The proportion of components whose molecular weight is less than the weight average molecular weight of the ethylene / α-olefin copolymer among components eluted at or below the temperature at which the elution amount determined from the integral elution curve is 50 wt%.
W ₂ : Ratio of components having a molecular weight equal to or higher than the weight average molecular weight of the ethylene / α-olefin copolymer among components eluted at or below the temperature at which the elution amount determined from the integral elution curve is 50 wt%.
W ₃ : The proportion of components having a molecular weight less than the weight average molecular weight of the ethylene / α-olefin copolymer among components eluted at a temperature higher than the temperature at which the elution amount determined from the integral elution curve is 50 wt%.
W ₄ : Ratio of components having a molecular weight equal to or higher than the weight average molecular weight of the ethylene / α-olefin copolymer among components eluted at a temperature higher than the temperature at which the elution amount obtained from the integral elution curve is 50 wt%.
Note that W ₁ + W ₂ + W ₃ + W ₄ = 100.
The value of W ₂ + W ₃ can be set within a predetermined range mainly by selecting a polymerization catalyst and polymerization conditions, and preferably within a predetermined range by using a specific metallocene catalyst. Can do.

2-6. Condition (6) W ₂ + W ₄
In the ethylene / α-olefin copolymer (B) in the present invention, the sum of W ₂ and W ₄ described in (1-5) (W ₂ + W ₄ ) is more than 25% by weight, less than 50% by weight, It is preferably more than 29% by weight, less than 50% by weight, more preferably more than 29% by weight, less than 45% by weight, still more preferably 30 to 43% by weight, particularly preferably 30 to 42% by weight. If W ₂ + W ₄ is 25% by weight or less, the high molecular weight component that effectively acts to improve the impact strength of the polyolefin resin contained in the ethylene / α-olefin copolymer (B) decreases, which is not preferable. , Which is not preferable because the high molecular weight long-chain branching component that acts particularly effectively on the improvement of the molding processability of the polyolefin-based resin contained in the ethylene / α-olefin copolymer is reduced or is not preferred. Since the ratio of the components is reduced, a large amount of blending is required due to the modification of the polyolefin resin, thereby deteriorating the economy. On the other hand, when the W ₂ + W ₄ value is 50% by weight or more, the dispersibility in the polyolefin-based resin is large because the ratio of the high molecular weight component and the high molecular weight long-chain branched component contained in the ethylene / α-olefin copolymer is large. Becomes worse, and transparency is deteriorated and gel is generated.

2-7. Condition ₍₇₎ W 2 -W ₄
In the ethylene / α-olefin copolymer (B) in the present invention, the difference (W ₂ −W ₄ ) between W ₂ and W ₄ described in (2-6) is more than 0% by weight and less than 20% by weight. , Preferably greater than 0%, less than 15%, more preferably greater than 1%, less than 15%, even more preferably greater than 2%, less than 14%, particularly preferably greater than 2%. , Less than 13% by weight. When W ₂ -W ₄ is 0% by weight or less, the low density high molecular weight component which acts particularly effectively on the impact strength improvement of the polyolefin resin contained in the ethylene / α-olefin copolymer (B) decreases. Therefore, it is not preferable. On the other hand, if the W ₂ -W ₄ value is 20% by weight or more, the balance between the content of the high density high molecular weight component and the low density high molecular weight component contained in the ethylene / α-olefin copolymer is lost, and the polyolefin resin This is not preferable because the physical property modification effect is not exhibited as expected, or the dispersibility in the polyolefin-based resin is deteriorated to cause deterioration of transparency and gel.

2-8. Condition (8) X
In the ethylene / α-olefin copolymer (B) in the present invention, the ratio (X value) of the component eluted at 85 ° C. or higher by temperature rising elution fractionation (TREF) is 2 to 15% by weight, preferably 3 to 3% by weight. 14% by weight. More preferably, it is 4 to 14% by weight. If the X value is greater than 15% by weight, the proportion of low density components that effectively act to improve the impact strength of the polyolefin resin contained in the ethylene / α-olefin copolymer (B) decreases, thereby improving the impact strength. Is not preferred because a larger amount of a blend of ethylene / α-olefin copolymer is required and is not economical. If the X value is less than 2% by weight, the compatibility with the polyolefin resin may deteriorate, and the rigidity of the polyolefin resin may deteriorate. The amount of X value is a numerical value that indicates the proportion of the relatively high molecular weight component contained in the copolymer, and can be adjusted by adjusting the catalyst and controlling the polymerization conditions.

[TREF measurement conditions]
A sample is dissolved in orthodichlorobenzene (containing 0.5 mg / mL BHT) at 140 ° C. to obtain a solution. This was introduced into a 140 ° C. TREF column, cooled to 100 ° C. at a rate of 8 ° C./min, subsequently cooled to 40 ° C. at a rate of 4 ° C./min, and then cooled at a rate of 1 ° C./min. To -15 ° C and hold for 20 minutes. Thereafter, orthodichlorobenzene (containing 0.5 mg / mL BHT) as a solvent is passed through the column at a flow rate of 1 mL / min, and the components dissolved in orthodichlorobenzene at −15 ° C. are eluted in the TREF column for 10 minutes. Next, the column is linearly heated to 140 ° C. at a temperature increase rate of 100 ° C./hour to obtain an elution curve. At this time, the amount of components eluted between 85 ° C. and 140 ° C. is X (unit: wt%).

The equipment used is as follows.
(TREF part)
TREF column: 4.3 mmφ × 150 mm stainless steel column Column packing material: 100 μm surface inactive glass beads Heating method: Aluminum heat block Cooling method: Peltier element (Peltier element is cooled by water)
Temperature distribution: ± 0.5 ° C
Temperature controller: Chino Corporation Digital Program Controller KP1000
(Valve oven)
Heating method: Air bath oven Measurement temperature: 140 ° C
Temperature distribution: ± 1 ° C
Valve: 6-way valve, 4-way valve (sample injection part)
Injection method: Loop injection method Injection amount: Loop size 0.1ml
Inlet heating method: Aluminum heat block Measurement temperature: 140 ° C
(Detection unit)
Detector: Fixed wavelength infrared detector FOXBORO MIRAN 1A
Detection wavelength: 3.42 μm
High-temperature flow cell: LC-IR micro flow cell, optical path length 1.5 mm, window shape 2φ × 4 mm oval, synthetic sapphire window Measurement temperature: 140 ° C.
(Pump part)
Liquid feed pump: SSC-3461 pump manufactured by Senshu Kagaku Co., Ltd. Measurement conditions Solvent: Orthodichlorobenzene (with 0.5 mg / mL BHT)
Sample concentration: 5 mg / mL
Sample injection volume: 0.1 mL
Solvent flow rate: 1 mL / min

2-9. Composition of the ethylene / α-olefin copolymer (B) of the present invention The ethylene / α-olefin copolymer (B) of the present invention is a copolymer of ethylene and an α-olefin having 3 to 10 carbon atoms. . Examples of the α-olefin which is a copolymerization component used here include propylene, butene-1, 3-methylbutene-1, 3-methylpentene-1, 4-methylpentene-1, pentene-1, hexene-1 and heptene. -1, octene-1, nonene-1, decene-1, and the like. These α-olefins may be used alone or in combination of two or more. Among these, more preferable α-olefins are those having 3 to 8 carbon atoms, specifically, propylene, butene-1, 3-methylbutene-1, 4-methylpentene-1, pentene-1, and hexene-1. , Heptene-1, octene-1, and the like. More preferable α-olefins have 4 or 6 carbon atoms, and specific examples include butene-1, 4-methylpentene-1, and hexene-1. A particularly preferred α-olefin is hexene-1.

  The proportion of ethylene and α-olefin in the ethylene / α-olefin copolymer (B) of the present invention is about 75 to 99.8% by weight of ethylene and about 0.2 to 25% by weight of α-olefin, preferably Is about 80 to 99.6% by weight of ethylene and about 0.4 to 20% by weight of α-olefin, more preferably about 82 to 99.2% by weight of ethylene and about 0.8 to 18% by weight of α-olefin. More preferably about 85 to 99% by weight of ethylene and about 1 to 15% by weight of α-olefin, and particularly preferably about 88 to 98% by weight of ethylene and about 2 to 12% by weight of α-olefin. If the ethylene content is within this range, the effect of modifying the polyethylene resin is high.

  The copolymerization may be any of alternating copolymerization, random copolymerization, and block copolymerization. Of course, a small amount of a comonomer other than ethylene or α-olefin may be used. In this case, styrenes such as styrene, 4-methylstyrene, 4-dimethylaminostyrene, 1,4-butadiene, 1,5- It has polymerizable double bonds such as dienes such as hexadiene, 1,4-hexadiene and 1,7-octadiene, cyclic compounds such as norbornene and cyclopentene, oxygen-containing compounds such as hexenol, hexenoic acid and methyl octenoate. A compound can be mentioned. However, it goes without saying that when diene is used, it must be used within the range where the long-chain branched structure and molecular weight distribution satisfy the above conditions.

3. Production Method of Ethylene / α-Olefin Copolymer (B) of the Present Invention The ethylene / α-olefin copolymer (B) of the present invention is produced and used so as to satisfy all the above conditions. The production is carried out by a method of copolymerizing ethylene and the above-mentioned α-olefin using an olefin polymerization catalyst.

As an example of a suitable production method for simultaneously realizing a specific long chain branched structure, composition distribution structure, MFR, and density of the ethylene / α-olefin copolymer of the present invention, a specific catalyst component (X ), (Y) and a method using an olefin polymerization catalyst containing (Z).
Catalyst component (X): a bridged cyclopentadienylindenyl compound containing a transition metal element.
Catalyst component (Y): A compound that reacts with the compound of component (X) to form a cationic metallocene compound.
Catalyst component (Z): inorganic compound carrier.

3-1. Catalyst component (X)
A preferred catalyst component (X) for producing the ethylene / α-olefin copolymer (B) of the present invention is a bridged cyclopentadienylindenyl compound containing a transition metal element, more preferably the following general formula: It is a metallocene compound represented by [1], more preferably a metallocene compound represented by the following general formula [2].

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

[In the formula [2], M represents a transition metal of Ti, Zr or Hf. Q ¹ represents a binding group that bridges the cyclopentadienyl ring and the indenyl ring. X and Y are each independently a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a hydrocarbon group having 1 to 20 carbon atoms including an oxygen atom or a nitrogen atom, or a carbon atom having 1 to 20 carbon atoms. A hydrogen-substituted amino group or an alkoxy group having 1 to 20 carbon atoms is shown. 10 Rs are each independently a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a silicon-containing hydrocarbon group having 1 to 18 carbon atoms including 1 to 6 silicon atoms, 20 halogen-containing hydrocarbon group, a C1-C20 hydrocarbon group containing an oxygen atom or a C1-C20 hydrocarbon group-substituted silyl group. ]

  A particularly preferable catalyst component (X) for producing the ethylene / α-olefin copolymer (B) of the present invention is a metallocene compound represented by the general formula (1c) described in JP2013-227271A. It is.

[However, in the formula (1c), all of the abbreviations are described in JP 2013-227271 A. That is, M ^1c represents a transition metal of Ti, Zr, or Hf. X ^1c and X ^2c each independently represent a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a hydrocarbon group having 1 to 20 carbon atoms including an oxygen atom or a nitrogen atom, or 1 to 20 carbon atoms. A hydrocarbon group-substituted amino group or an alkoxy group having 1 to 20 carbon atoms. Q ^1c and Q ^2c each independently represent a carbon atom, a silicon atom, or a germanium atom. R ^1c independently represents a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, and at least two of the four R ^1cs are bonded to form a ring together with Q ^1c and Q ^2c. Also good. ^mc is 0 or 1, and when ^mc is 0, Q ^1c is directly bonded to a conjugated 5-membered ring containing R ^2c . R ^2c and R ^4c are each independently a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a silicon-containing hydrocarbon group having 1 to 18 carbon atoms including 1 to 6 silicon atoms, or 1 carbon atom. -20 halogen-containing hydrocarbon group, a C1-C20 hydrocarbon group containing an oxygen atom, or a C1-C20 hydrocarbon group-substituted silyl group. R ^3c represents a substituted aryl group represented by the following general formula (1-ac). ]

[However, in the formula (1-ac), Y ^1c represents an atom of Group 14, 15 or 16 of the periodic table. R ^5c , R ^6c , R ^7c , R ^8c and R ^9c are each independently a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, a hydrocarbon group having 1 to 20 carbon atoms, a carbon number containing oxygen or nitrogen 1-20 hydrocarbon group, C1-C20 hydrocarbon group-substituted amino group, C1-C20 alkoxy group, C1-C18 silicon-containing hydrocarbon group containing 1-6 silicon atoms, carbon A halogen-containing hydrocarbon group having 1 to 20 carbon atoms, or a hydrocarbon group-substituted silyl group having 1 to 20 carbon atoms, wherein R ^5c , R ^6c , R ^7c , R ^8c and R ^9c are bonded to each other with adjacent groups; And may form a ring together with atoms bonded to them. n ^c is 0 or 1, and when n ^c is 0, there is no substituent R ^{5c in} Y ^1c . ^pc is 0 or 1, and when ^pc is 0, the carbon atom to which R ^7c is bonded and the carbon atom to which R ^9c are bonded are directly bonded. When Y ^1c is a carbon atom, at least one of R ^5c , R ^6c , R ^7c , R ^8c , and R ^9c is not a hydrogen atom. ]

In the general formula (1c), M ^1c of the metallocene compound represents Ti, Zr or Hf, M ^{1c of the} metallocene compound preferably represents Zr or Hf, and M ^{1c of the} metallocene compound more preferably represents Zr. Represent.

  The most preferred catalyst component (X) for producing the ethylene / α-olefin copolymer (B) of the present invention is a metallocene compound represented by the general formula (2c) described in JP2013-227271A It is.

In the metallocene compound represented by the above general formula (2c), M ^1c , X ^1c , X ^2c , Q ^1c , R ^1c , R ^2c and R ^4c are the descriptions of the metallocene compound represented by the above general formula (1c). The structure similar to the atom and group shown by can be selected. R ^10c can be selected from the same structure as the atoms and groups of R ^5c , R ^6c , R ^7c , R ^8c , and R ^9c shown in the description of the metallocene compound represented by the general formula (1c). .

  Specific examples of the metallocene compounds are described in General Formula (4c) and Tables 1c-1 to 1-5, and General Formulas (5c) and (6c) and Tables 1c-6 to 9 in JP2013-227271A. Examples of the compound include, but are not limited to these.

  The compound of the above specific example is preferably a zirconium compound or a hafnium compound, and more preferably a zirconium compound.

  As a preferable catalyst component (X) for producing the ethylene / α-olefin copolymer of the present invention, two or more of the above-mentioned crosslinked cyclopentadienyl indenyl compounds can be used.

3-2. Catalyst component (Y)
A preferred catalyst component (Y) for producing the ethylene / α-olefin copolymer (B) of the present invention is a compound that reacts with the compound of component (X) to form a cationic metallocene compound, and more preferably. Is the component (B) described in JP 2013-227271 A [0064] to [0083], and more preferably the organoaluminum oxy compound described in [0065] to [0069].

3-3. Catalyst component (Z)
A preferred catalyst component (Z) for producing the ethylene / α-olefin copolymer of the present invention is an inorganic compound carrier, and more preferably described in JP2013-227271A [0084] to [0088]. Inorganic compounds. At this time, the metal oxide described in the publication [0085] is preferable as the inorganic compound.

3-4. Production Method of Olefin Polymerization Catalyst The ethylene / α-olefin copolymer of the present invention is a copolymer of ethylene and the above α-olefin using the olefin polymerization catalyst containing the catalyst components (X) to (Z). It is suitably manufactured by the method. The contact method of each component when obtaining the olefin polymerization catalyst from the catalyst components (X) to (Z) of the present invention is not particularly limited. For example, the following methods (I) to (III) are optional. Can be adopted.

(I) The catalyst component (X) which is a bridged cyclopentadienylindenyl compound containing the transition metal element and the catalyst component which is a compound which reacts with the compound of the catalyst component (X) to form a cationic metallocene compound After contacting (Y), the catalyst component (Z), which is an inorganic compound carrier, is contacted.
(II) After contacting the catalyst component (X) and the catalyst component (Z), the catalyst component (Y) is contacted.
(III) After contacting the catalyst component (Y) and the catalyst component (Z), the catalyst component (X) is contacted.

  Of these contact methods, (I) and (III) are preferred, and (I) is most preferred. In any contact method, usually in an inert atmosphere such as nitrogen or argon, aromatic hydrocarbons such as benzene, toluene, xylene and ethylbenzene (usually having 6 to 12 carbon atoms), pentane, heptane, hexane and decane. , A method in which each component is brought into contact with stirring or non-stirring in the presence of a liquid inert hydrocarbon such as aliphatic or alicyclic hydrocarbon (usually having 5 to 12 carbon atoms) such as dodecane or cyclohexane. . This contact is usually −100 ° C. to 200 ° C., preferably −50 ° C. to 100 ° C., more preferably 0 ° C. to 50 ° C., for 5 minutes to 50 hours, preferably 30 minutes to 24 hours, more preferably. It is desirable to carry out in 30 minutes to 12 hours.

  When contacting the catalyst component (X), the catalyst component (Y), and the catalyst component (Z), as described above, an aromatic hydrocarbon solvent in which a certain component is soluble or hardly soluble, and a certain component Any insoluble or hardly soluble aliphatic or alicyclic hydrocarbon solvent can be used.

  In the case where the contact reaction between the components is performed stepwise, this may be used as it is as the solvent for the subsequent contact reaction without removing the solvent used in the previous step. In addition, after the previous catalytic reaction using a soluble solvent, liquid inert hydrocarbons in which certain components are insoluble or sparingly soluble (for example, aliphatics such as pentane, hexane, decane, dodecane, cyclohexane, benzene, toluene, xylene, etc.) Hydrocarbons, alicyclic hydrocarbons or aromatic hydrocarbons) and the desired product is recovered as a solid or once or part of the soluble solvent is removed by means such as drying. After removing the product as a solid, the subsequent catalytic reaction of the desired product can also be carried out using any of the inert hydrocarbon solvents described above. In this invention, it does not prevent performing contact reaction of each component in multiple times.

  In the present invention, the use ratio of the catalyst component (X), the catalyst component (Y) and the catalyst component (Z) is not particularly limited, but the following ranges are preferable.

  When an organoaluminum oxy compound is used as the catalyst component (Y), the atomic ratio (Al / M) of the aluminum of the organoaluminum oxy compound to the transition metal (M) in the catalyst component (X) is usually 1 to 100, 000, preferably 100 to 1000, more preferably 210 to 800, particularly preferably 250 to 500 is desirable. When a borane compound or a borate compound is used, it is based on the transition metal (M) in the catalyst component (X). The boron atomic ratio (B / M) is usually selected in the range of 0.01 to 100, preferably 0.1 to 50, and more preferably 0.2 to 10. Further, when a mixture of an organoaluminum oxy compound, a borane compound, and a borate compound is used as the catalyst component (Y), the same use as described above for the transition metal (M) for each compound in the mixture It is desirable to select by percentage.

  The catalyst component (Z) is used in an amount of 0.0001-5 mmol, preferably 0.001-0.2 mmol, more preferably 0.005-0.1 mmol of transition metal in the catalyst component (X). Especially preferably, it is 1 g per 0.01 to 0.04 mmol.

  In the present invention, the ratio of the number of moles of the metal of the catalyst component (Y) to 1 g of the catalyst component (Z) is preferably more than 0.005 and 0.020 (mol / g) or less, more preferably 0. More than 0.006 to 0.015 (mol / g) or less, more preferably more than 0.006 and 0.012 (mol / g) or less, particularly preferably 0.007 to 0.010 (mol / g). It is.

  The catalyst component (X), the catalyst component (Y), and the catalyst component (Z) are brought into contact with each other by appropriately selecting the contact methods (I) to (III) described above, and then the solvent is removed, An olefin polymerization catalyst can be obtained as a solid catalyst. The removal of the solvent is performed at normal pressure or reduced pressure at 0 to 200 ° C., preferably 20 to 150 ° C., more preferably 20 to 100 ° C. for 1 minute to 100 hours, preferably 10 minutes to 50 hours, more preferably 30 minutes. It is desirable to perform in ~ 20 hours.

The olefin polymerization catalyst can also be obtained by the following methods (IV) and (V).
(IV) The catalyst component (X) and the catalyst component (Z) are contacted to remove the solvent, which is used as a solid catalyst component, and an organoaluminum oxy compound, borane compound, borate compound or a mixture thereof under polymerization conditions Make contact.
(V) The catalyst component (Y), which is an organoaluminum oxy compound, borane compound, borate compound or a mixture thereof, is contacted with the catalyst component (Z) to remove the solvent, which is used as a solid catalyst component, In contact with the catalyst component (X).

  In the case of the contact methods (IV) and (V), the same conditions as described above can be used for the component ratio, contact conditions, and solvent removal conditions.

  Further, as an olefin polymerization catalyst suitable for obtaining the ethylene / α-olefin copolymer of the present invention, a catalyst component (Y) and a catalyst component (reacting with the catalyst component (X) to form a cationic metallocene compound) As a component also serving as Z), a well-known layered silicate described in JP-A Nos. 05-301917 and 08-127613 can be used. The layered silicate is a silicate compound having a crystal structure in which planes formed by ionic bonds or the like are stacked in parallel with each other with a weak binding force. Most layered silicates are naturally produced mainly as the main component of clay minerals, but these layered silicates are not limited to natural ones and may be artificially synthesized.

  Among these, montmorillonite, sauconite, beidellite, nontronite, saponite, hectorite, stevensite, bentonite, teniolite and the like, smectite group, vermiculite group and mica group are preferable.

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

  The olefin polymerization catalyst thus obtained may be used after the prepolymerization of the monomer if necessary.

3-5. Polymerization Method of Ethylene / α-Olefin Copolymer (B) The ethylene / α-olefin copolymer of the present invention preferably uses an olefin polymerization catalyst prepared by the production method described in 3-4 above. It is produced by copolymerizing ethylene and the above-mentioned α-olefin.

  As the α-olefin that is a comonomer, as described above, an α-olefin having 3 to 10 carbon atoms can be used, and two or more types of α-olefin can be copolymerized with ethylene. It is also possible to use small amounts of comonomers other than olefins.

  In the present invention, the copolymerization reaction can be preferably carried out by a gas phase method or a slurry method. In the case of gas phase polymerization, ethylene or the like is polymerized in a reactor in which a gas flow of ethylene or comonomer is introduced, circulated, or circulated in a state where oxygen and water are substantially cut off. In the case of slurry polymerization, an inert hydrocarbon selected from aliphatic hydrocarbons such as isobutane, hexane and heptane, aromatic hydrocarbons such as benzene, toluene and xylene, and alicyclic hydrocarbons such as cyclohexane and methylcyclohexane. Ethylene or the like is polymerized in the presence or absence of a solvent. Needless to say, liquid monomers such as liquid ethylene and liquid propylene can also be used as the solvent. In the present invention, more preferred polymerization is gas phase polymerization. The polymerization conditions are such that the temperature is 0 to 250 ° C., preferably 20 to 110 ° C., more preferably 60 to 100 ° C., and the pressure is normal pressure to 10 MPa, preferably normal pressure to 4 MPa, more preferably 0.5 to 2 MPa. The polymerization time is usually 5 minutes to 20 hours, preferably 30 minutes to 10 hours.

In order to obtain a copolymer having a relatively narrow inverse comonomer composition distribution having an appropriate range of long chain branching and an appropriate ratio of low density high molecular weight components, which is one of the features of the present invention, the catalyst components used ( In addition to the selection of the types of X) and catalyst component (Y), the molar ratio of catalysts (X) and (Y), the molar ratio of (X) and (Z), and the molar ratio of (Y) and (Z) The polymerization temperature, ethylene partial pressure, H2 / C2 ratio, comonomer / ethylene ratio, and other polymerization conditions can be changed as appropriate.
Specifically, for example, when the complex described in Example 1 of the present application is used, the catalyst is adjusted by complex / silica = 10 to 40 μmol / g, organoaluminum oxy compound / silica = 7 to 10 mmol / g, adjustment. The use of the agent is optional, polymerization conditions 60-90 ° C., ethylene partial pressure 0.3-2.0 MPa, H2 / C2% = 0.2-2.0%, C6 / C2 = 0.1-0. Set appropriately in the range of 8%.
Moreover, even if a component for the purpose of removing moisture, a so-called scavenger, is added to the polymerization system, the polymerization can be carried out without any trouble.

  Such scavengers include organoaluminum compounds such as trimethylaluminum, triethylaluminum and triisobutylaluminum, the organoaluminum oxy compounds, modified organoaluminum compounds containing branched alkyl, organozinc compounds such as diethyl zinc and dibutyl zinc, diethyl Organic magnesium compounds such as magnesium, dibutylmagnesium and ethylbutylmagnesium, and grinier compounds such as ethylmagnesium chloride and butylmagnesium chloride are used. Of these, triethylaluminum, triisobutylaluminum, and ethylbutylmagnesium are preferable, and triethylaluminum is particularly preferable.

The long chain branched structure (ie, g _c ) and comonomer copolymer composition distribution (ie, W _{1 to} W _4, etc.) of the produced copolymer are based on the types of catalyst component (X) and catalyst component (Y), the molar ratio of the catalyst It can be adjusted by changing the polymerization conditions such as polymerization temperature, pressure and time, and the polymerization process. Even if a catalyst component type that easily forms a long-chain branched structure is selected, a copolymer having a small long-chain branched structure can be produced, for example, by lowering the polymerization temperature or increasing the ethylene pressure. Even if a catalyst component species having a broad molecular weight distribution or copolymer composition distribution is selected, a copolymer having a narrow molecular weight distribution or copolymer composition distribution is produced by changing the catalyst component molar ratio, polymerization conditions or polymerization process, for example. It is also possible.

  The ethylene / α-olefin copolymer of the present invention can be used as long as the polymerization conditions are appropriately set even in a multi-stage polymerization system having two or more stages in which polymerization conditions such as hydrogen concentration, monomer amount, polymerization pressure, and polymerization temperature are different from each other. However, when the ethylene / α-olefin copolymer of the present invention is produced by a one-step polymerization reaction, it is more economical without setting complicated polymerization operating conditions. It is preferable because it can be manufactured.

4). Ethylene-based resin composition Hereinafter, ethylene / α- mainly satisfying one or more linear ethylene / α-olefin copolymers (A) of the present invention and (B-1) to (B-5). The ethylene resin composition comprising the olefin copolymer (B) and mainly suitable for film applications will be described in detail.

  Specifically, as the ethylene-based resin composition for films and sheets, 31 to 99% by weight of a linear ethylene / α-olefin copolymer (A) comprising at least one specific type of the present invention, 1 to 69% by weight of specific ethylene / α-olefin copolymer (B), preferably 50 to 99% by weight of (A), and 1 to 50% by weight of ethylene / α-olefin copolymer (B) The composition formed is mentioned.

4-1. MFR
The MFR of the ethylene-based resin composition for a film comprising the above components (A) and (B) needs to be in the range of 0.1 to 10 g / 10 minutes, preferably 0.2 to 5 g / 10 minutes, more preferably 0.3 to 3 g / 10 minutes.
If the MFR is lower than 0.1 g / 10 minutes, the fluidity is poor and the motor load of the extruder becomes too high. On the other hand, if the MFR is higher than 10 g / 10 minutes, the bubbles are not stable and difficult to mold. The strength of the film is lowered.
The MFR of the ethylene-based resin composition is a value measured under the conditions of 190 ° C. and 21.18 N (2.16 kg) load according to JIS K 7210, but the approximate MFR is the component (A), From each MFR and the ratio of (B), it can be calculated according to an additivity rule.

4-2. Density The density of the ethylene resin composition of the present invention comprising the above components (A) and (B) needs to be in the range of 0.910 to 0.950 g / cm ³ , preferably 0.915. a ~0.945g / cm ^3, more preferably 0.915 to 0.940 g / cm ^3.
When the density of the ethylene-based resin composition is lower than 0.910 g / cm ³ , the rigidity of the film is lowered, and the suitability of the automatic bag making machine is deteriorated. Moreover, when the density of the ethylene-based resin composition is higher than 0.950 g / cm ³ , the strength of the film is lowered.
In addition, the density of an ethylene-type resin composition can be computed according to an addition rule from each density and ratio of a component (A) and (B).

4-3. Condition (AB-1) Relationship between MFR of components (A) and (B) In preparing the ethylene-based resin composition of the present invention consisting of the components (A) and (B), the component (A) and As the MFR relationship of (B), it is preferable that MFR _A > MFR _B.
When the relationship between the MFR of the components (A) and (B) is MFR _A > MFR _B , the addition of the component (B) makes the bubbles more stable and improves the processing characteristics.

4-4. Condition (AB-2) Relationship between Densities of Components (A) and (B) In preparing the ethylene-based resin composition of the present invention consisting of the components (A) and (B), the component (A) and As the density relationship of (B), it is preferable that density _A > density _B.
When the density relationship between the components (A) and (B) is MFR _A > MFR _B , the strength of the film is improved by the addition of the component (B).

4-5. Condition (AB-3) Relationship between molecular weight distributions of components (A) and (B) In preparing the ethylene-based resin composition of the present invention consisting of the components (A) and (B), the component (A) And [Mw / Mn] in (B), it is preferable that [Mw / Mn] _A <[Mw / Mn] _B.
When the relationship of [Mw / Mn] of the above components (A) and (B) is [Mw / Mn] _A <[Mw / Mn] _B , the bubbles at the time of inflation molding by addition of the above component (B) are stable. In addition, the processing characteristics are improved.

5. Other formulations etc. In the present invention, as long as the characteristics of the present invention are not impaired, an antistatic agent, an antioxidant, an antiblocking agent, a nucleating agent, a lubricant, an antifogging agent, an organic or inorganic pigment, an ultraviolet ray, and the like. Known additives such as inhibitors, weathering agents, and dispersants can be added.
The ethylene-based resin composition of the present invention is mixed, if necessary, with various additives and copolymer components to be added or blended using a Henschel mixer, a super mixer, a tumbler mixer, etc. You may heat-knead with a twin-screw extruder, a kneader, etc., and pelletize.

6). Forming method The method for forming the film of the present invention is not particularly limited as long as it is a method that can effectively use the excellent processing characteristics and mechanical properties of the ethylene-based resin composition of the present invention. Examples of the molding method include various inflation molding methods, T-die film molding methods, calender molding methods, multilayer coextrusion molding machines, and multilayer film molding methods using a laminating process.
The thickness of the film (or sheet) thus obtained is not particularly limited, and a suitable thickness varies depending on the molding method and conditions. For example, in the case of inflation molding, it is about 5 to 300 μm, and in the case of T-die molding, it can be a film (or sheet) of about 5 μm to 5 mm.

7). Applications The polyethylene resin composition of the present invention is a polyethylene resin composition for film formation having a film thickness of 60 μm or more, and has a particularly improved melt property and excellent moldability compared to ordinary ethylene polymers. At the same time, the molded polyethylene film is particularly excellent in impact resistance, strong, and excellent in sealing strength, so it is excellent in suitability for automatic bag making machines, especially suitable for mass production, inner bags for paper bags, garbage bags, etc. It is used as a material for standard bags with dimensional standards and heavy-weight packaging bags that cannot be torn even when a large amount of heavy materials such as fertilizers and grains are packaged.

<Film forming method>
The film of the present invention is formed by inflation molding, but the specification and molding conditions of the inflation molding machine are not particularly limited, and conventionally known methods and conditions can be taken. For example, the diameter of the extruder is 10 to 600 mm, preferably 20 to 300 mm, more preferably 25 to 200 mm, and the ratio L / D of the diameter D to the length L from the bottom of the hopper to the cylinder tip is 8 to 45. , Preferably 12-36.

The die has a shape generally used for inflation molding, and has a flow path shape such as a spider type, a spiral type, a stacking type, etc., and has a diameter of 1 to 5000 mm, preferably 5 to 3000 mm, more preferably 10 to 1800 mm.
For cooling the bubble, a commonly used air ring is used, and a known cooling gas can be used. Further, the temperature can be cooled by a chiller or the like, or heated by a heater or the like. For cooling the bubbles, a known method of applying cooling air from an external air ring or circulating a cooling gas inside can be used. The air ring is not limited to its shape and number, and one or a plurality of known ones such as a single slit, a dual slit, and a chamber can be provided.

  As molding conditions, the resin extruded from the die has a temperature of 140 to 270 ° C., preferably 180 to 250 ° C., and the average discharge speed determined by the discharge amount and the die shape is 1 mm / min to 10 m. / Min, preferably 5 mm / min to 5 m / min, more preferably 10 mm / min to 1 m / min. The bubble exiting the die is expanded by the gas inside, and the blow ratio expressed by the ratio of the bubble diameter to the die aperture is in the range of 1.0 to 4.5, preferably 1.5 to 3.5. Yes, it can be molded under molding conditions such that the TUR represented by the ratio between the take-off speed and the average flow rate when extruded from the die is in the range of 2.0 to 200, preferably 10 to 100. The bubble is solidified by cooling, and the frost line height from the die outlet until the bubble is solidified varies depending on the film forming speed and the film thickness, but is 5 to 1800, preferably 10 to 1200 mm, more preferably 20 to 20 mm. It is in the range of 800 mm. Moreover, the film thickness of this invention is 60 micrometers or more, and is about 60-200 micrometers practically.

In the following, the present invention will be described in more detail with reference to examples and comparative examples, and the superiority of the present invention and the superiority in the structure of the present invention will be demonstrated, but the present invention is limited by these examples. It is not a thing.
In addition, the measuring method used in the Example and the comparative example is as follows. The following catalyst synthesis step and polymerization step were all performed under a purified nitrogen atmosphere, and the solvent used was dehydrated and purified with molecular sieve 4A.

[Measurement method of physical properties]
(1) MFR
In accordance with JIS K7210 "Plastic-thermoplastic melt mass flow rate (MFR) and melt volume flow rate (MVR) test methods", measurement was performed under the conditions of 190 ° C. and 21.18 N (2.16 kg) load. .
(2) Density JIS K7112 (1999 edition): Measured by method A (submersion method in water).
(3) Molecular weight distribution measured by GPC (Mw / Mn)
It measured by the gel permeation chromatography (GPC) method. The measurement conditions of GPC are as follows.

Apparatus: Waters GPC (ALC / GPC 150C)
Detector: MIRAN 1A IR detector manufactured by FOXBORO (measurement wavelength: 3.42 μm)
Column: AD806M / S (3 pieces) manufactured by Showa Denko KK
Mobile phase solvent: o-dichlorobenzene Measurement temperature: 140 ° C
Flow rate: 1.0 ml / min Injection volume: 0.2 ml
Sample preparation: Prepare a 1 mg / mL solution using ODCB (containing 0.5 mg / mL BHT) and dissolve it at 140 ° C. for about 1 hour.

  In addition, the baseline and the section of the obtained chromatogram were performed as illustrated in FIG. Conversion from the retention capacity to the molecular weight was performed using a standard curve prepared in advance with standard polystyrene. The standard polystyrenes used are all the following brands manufactured by Tosoh Corporation. F380, F288, F128, F80, F40, F20, F10, F4, F1, A5000, A2500, A1000.

A calibration curve is generated by injecting 0.2 mL of a solution dissolved in ODCB (containing 0.5 mg / mL BHT) so that each is 0.5 mg / mL. For the calibration curve, a cubic equation obtained by approximation by the least square method was used. For conversion to molecular weight, a general calibration curve was used with reference to “Size Exclusion Chromatography” written by Sadao Mori (Kyoritsu Shuppan). The following numerical value was used for the viscosity formula [η] = K × Mα used at that time.
PS: K = 1.38 × 10 −4, α = 0.7
PE: K = 3.92 × 10 −4, α = 0.733

(4) Minimum value (gc) of molecular weight between 100,000 and 1,000,000 of the branching index (g ′) measured by a GPC measuring device combining a differential refractometer, a viscosity detector, and a light scattering detector
Waters Alliance GPCV2000 was used as a GPC apparatus equipped with a differential refractometer (RI) and a viscosity detector (Viscometer). In addition, as a light scattering detector, a DAWN-E manufactured by Wyatt Technology, a multi-angle laser light scattering detector (MALLS) was used. The detectors were connected in the order of MALLS, RI, and Viscometer. The mobile phase solvent is 1,2,4-trichlorobenzene (added with the antioxidant Irganox 1076 at a concentration of 0.5 mg / mL). The flow rate is 1 mL / min. As a column, two Tosoh Corporation GMHHR-H (S) HT were connected and used. The temperature of the column, sample injection section, and each detector is 140 ° C. The sample concentration was 1 mg / mL. The injection volume (sample loop volume) is 0.2175 mL. In order to obtain the absolute molecular weight (M) obtained from MALLS, the inertial square radius (Rg), and the intrinsic viscosity ([η]) obtained from Viscometer, data processing software ASTRA (version 4.73.04) attached to MALLS was used. The calculation was performed with reference to the above-mentioned literature.

[Calculation of branching index (gC), etc.]
The branching index (g ′) is calculated as a ratio (ηbranch / ηlin) between the intrinsic viscosity (ηbranch) obtained by measuring the sample with the above Viscometer and the intrinsic viscosity (ηlin) obtained separately by measuring a linear polymer. did.

  As the absolute molecular weight obtained from MALLS, the minimum value of the above g ′ at a molecular weight of 100,000 to 1,000,000 was calculated as gC. Here, linear polyethylene Standard Reference Material 1475a (National Institute of Standards & Technology) was used as the linear polymer.

(5) Ratio of components eluted at 85 ° C. or higher by temperature rising elution fractionation (TREF) (X)
A sample is dissolved in orthodichlorobenzene (containing 0.5 mg / mL BHT) at 140 ° C. to obtain a solution. This was introduced into a 140 ° C. TREF column, cooled to 100 ° C. at a rate of 8 ° C./min, subsequently cooled to 40 ° C. at a rate of 4 ° C./min, and then cooled at a rate of 1 ° C./min. To -15 ° C and hold for 20 minutes. Thereafter, orthodichlorobenzene (containing 0.5 mg / mL BHT) as a solvent is passed through the column at a flow rate of 1 mL / min, and the components dissolved in orthodichlorobenzene at −15 ° C. are eluted in the TREF column for 10 minutes. Next, the column is linearly heated to 140 ° C. at a temperature increase rate of 100 ° C./hour to obtain an elution curve. At this time, the amount of components eluted between 85 ° C. and 140 ° C. is X (unit: wt%).

The equipment used is as follows.
(TREF part)
TREF column: 4.3 mmφ × 150 mm stainless steel column Column packing material: 100 μm surface inactive glass beads Heating method: Aluminum heat block Cooling method: Peltier element (Peltier element is cooled by water)
Temperature distribution: ± 0.5 ° C
Temperature controller: Chino Corporation Digital Program Controller KP1000
(Valve oven)
Heating method: Air bath oven Measurement temperature: 140 ° C
Temperature distribution: ± 1 ° C
Valve: 6-way valve, 4-way valve (sample injection part)
Injection method: Loop injection method Injection amount: Loop size 0.1ml
Inlet heating method: Aluminum heat block Measurement temperature: 140 ° C
(Detection unit)
Detector: Fixed wavelength infrared detector FOXBORO MIRAN 1A
Detection wavelength: 3.42 μm
High-temperature flow cell: LC-IR micro flow cell, optical path length 1.5 mm, window shape 2φ × 4 mm oval, synthetic sapphire window Measurement temperature: 140 ° C.
(Pump part)
Liquid feed pump: SSC-3461 pump manufactured by Senshu Kagaku Co., Ltd. Measurement conditions Solvent: Orthodichlorobenzene (with 0.5 mg / mL BHT)
Sample concentration: 5 mg / mL
Sample injection volume: 0.1 mL
Solvent flow rate: 1 mL / min

(6) W ₂ + W ₃ , W ₂ + W ₄ , W ₂ -W ₄ ,
This was carried out by cross-fractionation chromatography (CFC) comprising a temperature rising elution fractionation (TREF) portion for performing crystalline fractionation and a gel permeation chromatography (GPC) portion for carrying out molecular weight fractionation.

  That is, after completely dissolving a polymer sample in orthodichlorobenzene (ODCB) containing 0.5 mg / mL BHT at 140 ° C., this solution was passed through a sample loop of the apparatus, and the TREF column (inert The polymer sample was crystallized by gradually cooling to a predetermined first elution temperature.

  After maintaining at a predetermined temperature for 30 minutes, ODCB is passed through a TREF column, whereby the eluted component is injected into the GPC section to perform molecular weight fractionation, and an infrared detector (MIRAN 1A IR detector manufactured by FOXBORO, A chromatogram was obtained with a measurement wavelength of 3.42 μm. Meanwhile, in the TREF part, the temperature was raised to the next elution temperature, and after obtaining the chromatogram of the first elution temperature, the elution component at the second elution temperature was injected into the GPC part. Thereafter, by repeating the same operation, chromatograms of the eluted components at each elution temperature were obtained.

  The CFC measurement conditions are as follows.

Equipment: CFC-T102L manufactured by Dia Instruments
GPC column: Showa Denko AD-806MS (3 connected in series)
Solvent: ODCB
Sample concentration: 3 mg / mL
Injection volume: 0.4mL
Crystallization rate: 1 ° C / min Solvent flow rate: 1 mL / min GPC measurement time: 34 minutes Stabilization time after GPC measurement: 5 minutes Elution temperature: 0, 5, 10, 15, 20, 25, 30, 35, 40, 45 49, 52, 55, 58, 61, 64, 67, 70, 73, 76, 79, 82, 85, 88, 91, 94
97, 100, 102, 120, 140

Data analysis From the chromatogram of the elution components obtained at each elution temperature obtained by measurement, the elution amount (proportional to the area of the chromatogram) normalized so that the sum total was 100% was determined.
Moreover, molecular weight distribution was calculated | required by the same procedure as the above-mentioned GPC from each chromatogram.

  From the molecular weight distribution and the elution amount at each elution temperature, the literature (S. Nakano, Y. Goto, “Development of Automatic Cross Fractionation: Combination of Crystallization Fractionation and Molecular Weight. , Pp. 4217-4231 (1981)), a graph (contour map) showing the elution amount relating to the elution temperature and molecular weight as contour lines was obtained.

The following component amounts were determined using the above contour map.
W ₁ : The proportion of components whose molecular weight is less than the weight average molecular weight of the ethylene / α-olefin copolymer among components eluted at or below the temperature at which the elution amount determined from the integral elution curve is 50 wt%.
W ₂ : Ratio of components having a molecular weight equal to or higher than the weight average molecular weight of the ethylene / α-olefin copolymer among components eluted at or below the temperature at which the elution amount determined from the integral elution curve is 50 wt%.
W ₃ : The proportion of components having a molecular weight less than the weight average molecular weight of the ethylene / α-olefin copolymer among components eluted at a temperature higher than the temperature at which the elution amount determined from the integral elution curve is 50 wt%.
W ₄ : Ratio of components having a molecular weight equal to or higher than the weight average molecular weight of the ethylene / α-olefin copolymer among components eluted at a temperature higher than the temperature at which the elution amount obtained from the integral elution curve is 50 wt%.
Note that W ₁ + W ₂ + W ₃ + W ₄ = 100.

[Formation conditions for blown film]
An inflation film was molded and evaluated under the following molding conditions using an inflation film film forming machine (molding apparatus) having the following 50 mmφ extruder.

Equipment: Inflation molding equipment Extruder screw diameter: 50mmφ
Die diameter: 75mmφ
Extrusion amount: 20kg / hr
Die lip gap: 3.0mm
Take-up speed: 7.5 m / min Blow-up ratio: 1.5
Molding resin temperature: 220 ° C
Film thickness: 130 μm

[Film evaluation method]
(1) Tensile modulus:
Based on JIS K7127-1999, the tensile elastic modulus when deformed by 1% in the film processing direction (MD) and the film width direction (TD) was measured.
(2) Dart drop impact strength (DDI)
It measured based on JIS K 7124 1 A method.
(3) Heat seal strength Two inflation molded films were stacked, heat sealed under the condition of temperature: 200 ° C., and a 180-degree peel strength with a width of 15 mm was measured.
(4) Melt Tension Using a Capillograph manufactured by Toyo Seiki Seisakusho, heat-stabilized resin obtained from a film at 190 ° C in a furnace was extruded from an orifice with an inner diameter of 2.095 mm and a length of 8 mm at a piston speed of 1 cm / min. The molten resin thus obtained was pulled at a speed of 4 m / min, and the resistance force generated at that time was measured to obtain a melt tension value.

[Example 1]
<Polymerization example 1 of ethylene / α-olefin polymer (B)>
(1) Synthesis of Bridged Cyclopentadienyl Indenyl Compound Dimethylsilylene (4- (4-trimethylsilyl-phenyl) -indenyl) (cyclopentadienyl) zirconium dichloride was synthesized according to the method described in JP2013-227271A. did.
(2) Synthesis of Olefin Polymerization Catalyst Under a nitrogen atmosphere, 30 g of silica fired at 400 ° C. for 5 hours was placed in a 500 ml three-necked flask, and then 195 ml of dehydrated toluene was added to form a slurry. In a separately prepared 200 ml two-necked flask, 412 milligrams of dimethylsilylene (4- (4-trimethylsilyl-phenyl) -indenyl) (cyclopentadienyl) zirconium dichloride synthesized in (1) above was placed in a nitrogen atmosphere and dehydrated toluene. After dissolving at 80.7 ml, 78.9 ml of a 20% methylaluminoxane / toluene solution made by Albemarle was further added at room temperature and stirred for 30 minutes. While heating and stirring a 500 ml three-necked flask containing a silica toluene slurry in an oil bath at 40 ° C., the whole toluene solution of the reaction product of the zirconocene complex and methylaluminoxane was added. After stirring at 40 ° C. for 1 hour, the solution is allowed to settle for 15 minutes while being heated to 40 ° C., and 221 ml of the supernatant is removed. By adding dehydrated hexane, stirring, allowing to settle, and removing the supernatant, the toluene content in the solvent is reduced. After substituting until it became 3% or less, it was distilled off under reduced pressure to obtain a powdered catalyst.
(3) Treatment of Olefin Polymerization Catalyst Under a nitrogen atmosphere, 32 g of the powdered catalyst obtained in (2) above was placed in a 500 ml three-necked flask, and 195 ml of dehydrated hexane and dehydrated liquid paraffin (manufactured by MORESCO; trade name: Moresco) White P-120) 180 g of a mixed solution was added at room temperature and stirred for 10 minutes.
(4) Production of ethylene / 1-hexene copolymer Ethylene / 1-hexene gas phase continuous copolymerization was carried out using the slurry catalyst obtained in (3) above. That is, 0.027 g / hour of the powdered catalyst was added to a gas phase continuous polymerization apparatus prepared at a temperature of 85 ° C., a hexene / ethylene molar ratio of 0.43%, a hydrogen / ethylene molar ratio of 0.52%, and an ethylene pressure of 1.5 MPa. Polymerization was carried out at a constant gas composition and temperature while intermittently feeding at a rate of 5 mm. In order to maintain cleanliness in the system, triethylaluminum (TEA) was supplied to the gas circulation line at 0.04 mmol / hr. As a result, the average production rate of the produced polyethylene was 180 g / hour (average residence time 10 hours). The MFR and density of the ethylene / 1-hexene copolymer obtained after producing a cumulative amount of 5 kg or more of polyethylene were 0.36 g / 10 minutes and 0.921 g / cm ³ , respectively. The results are shown in Table 2.

  To the polymer, 1000 ppm of an antioxidant (Sumitomo Chemical Co., Ltd., Sumitizer GP) was added and extruded using a single screw extruder (Union Plastics USV type 30φ extruder) at an extrusion temperature of 180 ° C. for evaluation. Pelletized.

[Comparative polymer 1]
Using low-density polyethylene (LF122 manufactured by Nippon Polyethylene Co., Ltd .; density 0.922 g / cm ³ , MFR 0.3 g / 10 min) manufactured by the high-pressure method, the physical properties and moldability of the material were the same as in Polymerization Example 1. evaluated. The results are shown in Table 2.

[Comparative polymer 2]
Using a commercially available metallocene polyethylene having a long chain branch (CU5001 manufactured by Sumitomo Chemical Co., Ltd .; density is 0.922 g / cm ³ , MFR is 0.3 g / 10 min), the material properties and moldability are evaluated in the same manner as in Polymerization Example 1. did. The results are shown in Table 2.

[Film forming experiment]
In order to confirm the modification effect of the polyolefin resin by the ethylene / α-olefin copolymer of the present invention, the following film forming experiment was conducted.

  The ethylene / α-olefin copolymer of the present invention has an excellent performance as a polyolefin-based resin modifier, because the copolymer of the present invention and the copolymer not of the present invention are added in a predetermined amount. It can be shown by molding a polyolefin resin composition obtained by blending into a blown film and measuring the physical properties of the film thus obtained.

(Example 1, Comparative Example 1, Comparative Example 2)
As the ethylene / α-olefin copolymer (A) serving as the base resin of the resin composition, Ziegler linear low density polyethylene (MFR = 0.5 g / 10 min, density = 0.922 g / cm 3) is used. Examples (Example 1), in which Polymer Example 1 (B), which is an ethylene copolymer having a long chain branch of the present invention, was blended in parts by weight shown in Table 3, Comparative Polymer 1, that is, a high-pressure radical Example of blending LF122, which is a low-density polyethylene (Comparative Example 1), Comparative Polymer 2, that is, ethylene having a known long-chain branch that is not commercially available and is not equivalent to the copolymer (B) of the present invention An example (Comparative Example 2) in which CU5001 is blended as the system copolymer (B) is shown.

  In order to evaluate as a resin composition, it is important that the melt tension and density as a resin composition are constant, so that the melt tension and density as a resin composition become substantially constant. The blending amount of each resin was adjusted. After the blended resin was stirred and mixed, the obtained resin composition was molded based on the above-described inflation molding conditions to obtain a film. Table 3 shows the physical properties of the obtained film.

  Further, FIG. 4 is a graph showing the relationship between the melt tension and the dart drop impact strength of Example 1, Comparative Example 1, Comparative Example 2, and Ziegler-Natta linear low density polyethylene which is the resin used in them. FIG. 5 shows a graph showing the relationship between the seal strength and the dart drop impact strength.

(Example 2, Comparative Example 3, Comparative Example 4)
As the ethylene / α-olefin copolymer (A) serving as the base resin of the resin composition, metallocene linear low density polyethylene (MFR = 1.0 g / 10 min, density = 0.922 g / cm 3) is used. In addition, an example in which the ethylene copolymer (B) having a long chain branch of the present invention was blended in parts by weight shown in Table 3 (Example 2), and an example in which LF122, which is a high-pressure radical method low-density polyethylene, was blended (comparison) Example 3) An example (Comparative Example 4) in which CU5001 is blended as a commercially available ethylene-based copolymer (B) having a long-chain branch which is not equivalent to the copolymer (B) of the present invention is shown. .

  In order to evaluate as a resin composition, it is important that the melt tension and density as a resin composition are constant, so that the melt tension and density as a resin composition become substantially constant. The blending amount of each resin was adjusted. After the blended resin was stirred and mixed, the obtained resin composition was molded based on the above-described inflation molding conditions to obtain a film. Table 3 shows the physical properties of the obtained film.

[Evaluation]
Hereinafter, the description of the present embodiment and the comparative example will be described based on the data shown in Tables 2 and 3.
Further, FIG. 4 is a graph showing the relationship between the melt tension and the dart drop impact strength of Example 1, Comparative Example 1, Comparative Example 2, and the Ziegler-Natta linear low density polyethylene which is the base resin used in them. FIG. 5 shows a graph showing the relationship between the seal strength and the dart drop impact strength.

  As is apparent from the graphs shown in FIGS. 4 and 5, Comparative Example 1 (□ in the graph) in which a high-pressure radical method low-density polyethylene is blended with the base resin, a commercially available ethylene-based heavy polymer having long chain branches. In Comparative Example 2 (Δ mark in the graph) in which the coalescence is blended, the melt tension is improved, but the dart drop impact strength is remarkably lowered. In addition, while the heat seal strength is not sufficiently improved, in Example 1 (marked with ● in the graph) in which the specific ethylene polymer (B) of the present invention is blended, the reduction rate of the dart drop impact strength is extremely small. In addition, the heat seal strength is extremely improved.

  Comparative Examples 1 and 3 are systems in which high-pressure radical method low-density polyethylene LF122 is added to Ziegler-Natta linear low-density polyethylene or metallocene linear low-density polyethylene, and the dart drop impact strength is larger than that of the examples. Inferior, strength is not preferred.

  Comparative Examples 2 and 4 are an ethylene copolymer having a long-chain branch that does not satisfy the requirements of the ethylene copolymer (B) of the present application with respect to Ziegler-Natta linear low density polyethylene or metallocene linear low density polyethylene. It is a system to which CU5001 as a coalescence is added, and the dart drop impact strength is greatly inferior to that of the examples, and the strength is not preferable.

  Compared to these comparative examples, as shown in the examples, the resin composition according to the present invention has excellent heat seal strength and dart drop impact strength, while the melt tension and tensile modulus are almost the same as the comparative examples. Was confirmed.

  The polyethylene film molded with the resin composition of the present invention has improved impact strength while maintaining the sealing strength and film waist required for the quality of heavy packaging bags containing heavy items such as rice bags and fertilizer bags. Thus, it is possible to economically provide a thin molded product.

  Therefore, the industrial value of the polyethylene resin composition of the present invention, which can economically advantageously provide a molded product having such desirable characteristics, is extremely large.

Claims (7)

A polyethylene-based resin composition for film molding having a film thickness of 60 μm or more, and one or more types of linear ethylene / α-olefin satisfying the following conditions (A-1) to (A-3) The polymer (A) 31 to 99% by weight and the ethylene / α-olefin copolymer (B) 1 to 69% by weight satisfying the following conditions (B-1) to (B-5): And the polyethylene-type resin composition characterized by the whole composition satisfy | filling conditions (C-1)-conditions (C-2).
Conditions for ethylene / α-olefin copolymer (A);
(A-1) MFR _A = 0.1 to 10 g / 10 min (A-2) Density _A = 0.900 to 0.960 g / cm ³
(A-3) Molecular weight distribution [Mw / Mn] measured by gel permeation chromatography (GPC) _A is 2.0 to 10.0.
Conditions for the ethylene polymer (B);
(B-1) MFR _B = 0.1 g / 10 min to 10 g / 10 min (B-2) Density _B = 0.895 to 0.940 g / cm ³
(B-3) Molecular weight distribution [Mw / Mn] measured by gel permeation chromatography (GPC) _B is 3.0 to 5.5 (B-4) Differential refractometer, viscosity detector and light scattering The minimum value (gc) of the branching index g ′ measured by a GPC measuring apparatus combined with a detector between 100,000 and 1,000,000 is 0.40 to 0.85 (B-5) Cross fractionation chromatography From the component (W ₂ ) of which the molecular weight is equal to or higher than the weight average molecular weight among the components eluted at or below the temperature at which the elution amount determined from the integrated elution curve measured by chromatography (CFC) is 50 wt%, and the integrated elution curve The sum (W ₂ + W ₃ ) of the proportions (W ₃ ) of the components whose molecular weight is less than the weight average molecular weight out of the components eluted at a temperature higher than the temperature at which the obtained elution amount is 50 wt% is 40% by weight. And less than 56% by weight
Overall composition conditions;
(C-1) MFR = 0.1 to 10 g / 10 min (C-2) Density = 0.910 to 0.950 g / cm ³ The polyethylene-based resin composition according to claim 1, wherein the ethylene / α-olefin copolymer (B) further satisfies the following condition (B-6).
(B-6) Ratio of components having a molecular weight equal to or higher than the weight average molecular weight among the components eluted at a temperature higher than the temperature at which the elution amount obtained from the integral elution curve measured by W ₂ and CFC is 50 wt% (W ₄ ) Sum (W ₂ + W ₄ ) is more than 25 wt% and less than 50 wt% The polyethylene-based resin composition according to claim 1 or 2, wherein the ethylene / α-olefin copolymer (B) satisfies the following condition (B-7).
(B-7) The difference between W ₂ and W ₄ (W ₂ −W ₄ ) is more than 0% by weight and less than 20% by weight. The polyethylene-based resin composition according to any one of claims 1 to 3, wherein the ethylene / α-olefin copolymer (B) further satisfies the following condition (B-8).
(B-8) The ratio (X) of the component that elutes at 85 ° C. or higher by temperature rising elution fractionation (TREF) is 2 to 15% by weight.   The polyethylene resin composition according to any one of claims 1 to 4, wherein the α-olefin of the ethylene / α-olefin copolymer (B) has 3 to 10 carbon atoms. A polymer that satisfies the following conditions is used as the ethylene / α-olefin copolymer (A) and the ethylene / α-olefin copolymer (B). The polyethylene-based resin composition described in 1.
(AB-1) MFR _A > MFR _B
(AB-2) Density _A > Density _B
(AB-3) [Mw / Mn] _A <[Mw / Mn] _B   A heavy weight packaging bag film comprising the resin composition according to any one of claims 1 to 6.

Images