JP6772444B2 - Resin composition for film and film - Google Patents

Description

The present invention relates to a resin composition for a film containing a specific ethylene / α-olefin copolymer as a main component, and more specifically, an ethylene capable of forming a film having excellent moldability and impact strength for a film. The present invention relates to a resin composition for a film containing an α-olefin copolymer as a main component, and a film obtained by T-die molding or inflation molding the resin composition for the film and a product using the film.

In the conventional ethylene-based polymer, which is widely used for packaging materials, there is a strong demand for further improvement of physical properties in addition to molding processability, which is suitable for any of various molding methods. The melt flow characteristics that control the molding processability are roughly classified into the extrusion property related to the molten resin pressure under shear stress and the molding stability related to the melt elasticity at the time of elongation deformation. Specifically, for example, in extrusion molding. Moldability is required according to various molding methods, such as low viscosity under high shear stress, stable bubbles under high-speed molding of inflation molding, and small neck-in in T-dies for extrusion lamination molding. It is very difficult to meet all of these.

Conventionally, so-called linear low-density polyethylene (LLDPE or metallocene PE) has a linear molecular structure, and is therefore known to be superior in strength to conventional high-pressure polyethylene having a large number of branched branches. .. However, in general, the molding process of polyethylene-based resin is carried out in a molten state, but when trying to produce with a film thickness of about 50-200 μm, it is necessary to increase the resin extrusion amount per unit time, and it is used alone. In the case of LLDPE and metallocene PE, it is difficult to ensure sufficient molding processability due to insufficient melt characteristics in terms of fluidity and insufficient elongational viscosity.

As measures to compensate for these, high-pressure polyethylene having excellent moldability has been blended, and ethylene-based polymers having different molecular weights and densities have been blended to improve melt characteristics and solid-state physical properties ( For example, see Patent Documents 1 to 3). However, although these blends (ethylene-based resin compositions) can obtain molding processability, there is a problem that the impact strength is lowered due to the blending of high-pressure polyethylene.

On the other hand, in recent years, as one of the other attempts to improve the molding processability of LLDPE, various attempts have been made to produce an ethylene-based polymer having a long-chain branched structure by introducing long-chain branched into linear low-density polyethylene. (For example, Patent Documents 4 and 5). However, the characteristics of each ethylene-based polymer depend on the type and polymerization conditions of the catalyst used and the type and amount of other compounds to be added, for example, the length of long-chain branching, the frequency of branching, and the overall molecular weight and molecular weight distribution. Etc. are different. Therefore, at present, several kinds of ethylene-based polymers having long-chain branches are commercially available, but they are used as the main component of a resin composition for a film, which requires high forming processability, rigidity, impact resistance and heat seal strength. As a polymer, it was still inadequate.

Under such circumstances, a resin composition for a film capable of solving the problems of the conventional ethylene-based resin composition and producing a film having excellent molding processability and excellent impact strength, and a resin composition for film obtained thereby. The development of a polyethylene-based film has been desired.

Japanese Unexamined Patent Publication No. 7-149962 Japanese Unexamined Patent Publication No. 9-31260 Japanese Unexamined Patent Publication No. 2006-312753 Japanese Unexamined Patent Publication No. 2012-31270 Japanese Unexamined Patent Publication No. 09-031260

An object of the present invention is to provide an ethylene / α-olefin copolymer for a film main component, which has excellent molding processability and impact strength of a polyolefin resin in view of the above-mentioned problems of the prior art. To provide a film having excellent moldability and impact strength obtained by T-die and inflation molding a resin composition for a film containing the ethylene / α-olefin copolymer as a main component, and the use of the film. It is in.

As a result of diligent studies to achieve the above problems, the present inventors have obtained molding processing characteristics and impact when a specific ethylene / α-olefin copolymer is used as the main component of the resin composition for a film. We have found that it is excellent in strength and have completed the present invention.

That is, the present invention, in one aspect,
<1> A resin composition for a film containing 60% by weight or more of an ethylene / α-olefin copolymer as a main component, which is characterized by satisfying the following conditions (1) to (5);
(1) MFR exceeds 0.1 g / 10 minutes and is 10 g / 10 minutes or less (2) Density is 0.895 to 0.940 g / cm ³ (3) By gel permeation chromatography (GPC) The measured molecular weight distribution Mw / Mn is 3.0 to 5.5. (4) Molecular weight of branch index g'measured by a GPC measuring device combining a differential refraction meter, a viscosity detector and a light scattering detector. The minimum value (gc) between 10,000 and 1,000,000 is 0.40 to 0.85. (5) The elution amount determined from the integrated elution curve measured by cross fractionation chromatography (CFC) is 50 wt%. The molecular weight of the components eluted at a temperature higher than the ratio (W ₂ ) of the components whose molecular weight is equal to or higher than the weight average molecular weight and the elution amount obtained from the integrated elution curve is 50 wt%. The sum (W ₂ + W ₃ ) of the proportions of components (W ₃ ) less than the weight average molecular weight is greater than 40% by weight and less than 80% by weight;
<2> The resin composition for a film according to <1> above, wherein the ethylene / α-olefin copolymer further satisfies the following conditions (6) or (7);
(6) The ratio (W ₄ ) of the components whose molecular weight is equal to or higher than the weight average molecular weight among the components eluted at a temperature higher than the temperature at which the elution amount obtained from the integrated elution curves measured by W ₂ and CFC is 50 wt%. The sum (W ₂ + W ₄ ) is more than 25% by weight and less than 50% by weight. (7) Higher temperature than the temperature at which the elution amount obtained from the integrated elution curves measured by W ₂ and CFC is 50 wt%. in the difference between the percentage of the molecular weight is weight average molecular weight or more components of the eluting component _{(W 4) (W 2 -W} 4) is greater than 0 wt% and less than 20 wt%;
<3> The film resin composition according to <1> or <2> above, wherein the content of the ethylene / α-olefin copolymer in the resin composition is 85% by weight or more. ;
<4> The film resin according to any one of <1> to <3> above, wherein the α-olefin in the ethylene / α-olefin copolymer has 3 to 10 carbon atoms. Composition;
<5> The resin composition for a film according to any one of <1> to <4> above, wherein the ethylene / α-olefin copolymer further satisfies the following condition (8). ;
(8) The ratio (X) of the component eluted at 85 ° C. or higher by the temperature-increasing elution fractionation (TREF) is 2 to 15% by weight.

Moreover, in another aspect, the present invention
<6> The ethylene / α-olefin copolymer is produced by a catalyst for olefin polymerization containing catalyst components (A), (B) and (C), and the above-mentioned <1> to <5. > The method for producing a resin composition for a film according to any one of the above;
Catalyst component (A): A crosslinked cyclopentadienyl indenyl compound containing a transition metal element.
Catalyst component (B): A compound that reacts with the compound of component (A) to produce a cationic metallocene compound.
Catalyst component (C): Inorganic compound carrier;
Is to provide.

In a further aspect, the invention
<7> A film comprising the resin composition for a film according to any one of <1> to <5> above is provided.

The film resin composition of the present invention uses a specific ethylene / α-olefin copolymer as the main component of the film resin composition, and particularly when the ethylene / α-olefin copolymer is used alone. However, it has excellent molding characteristics and impact strength. Further, a film obtained by T-die molding or inflation molding of a resin composition containing the ethylene / α-olefin copolymer as a main component also has excellent impact strength.

It is a graph which shows the baseline and interval of the chromatogram used by the gel permeation chromatography (GPC) method. It is a graph which shows the relationship between the branching index (g') and the molecular weight (M) calculated from GPC-VIS measurement (branching structure analysis). It is a graph which shows the elution temperature distribution by the temperature rise elution fractionation (TREF).

The present invention relates to a resin composition for a film containing an ethylene / α-olefin copolymer for a film having a specific long chain branching index and a composition distribution index and having a specific MFR and density as a main component. Is. Hereinafter, the conditions (1) to (5) that characterize the ethylene / α-olefin copolymer used in the resin composition for a film of the present invention, particularly the ethylene / α-olefin copolymer, and further preferable conditions. (6) to (8) and the production method of the ethylene / α-olefin copolymer, in particular, each component of the polymerization catalyst used in the production method, the preparation method thereof, and the polymerization method will be described in detail for each item. To do.

1. 1. Ethylene / α-olefin copolymer The ethylene / α-olefin copolymer used as the main component in the resin composition for a film of the present invention is characterized by satisfying all of the conditions (1) to (5) described below. It is preferable that the conditions (6), (7) or (8) are further satisfied.

1-1. Condition (1) MFR
The melt flow rate (MFR) of the ethylene / α-olefin copolymer used in the present invention is more than 0.1 g / 10 minutes and less than 10 g / 10 minutes, preferably more than 0.1 g / 10 minutes. It is 0 g / 10 minutes or less, more preferably 0.1 g / 10 minutes or more, and 2.0 g / 10 minutes or less.

When the MFR is in this range, the processing characteristics when processing the film and the impact strength of the processed film are excellent. On the other hand, if the MFR is 0.1 g / 10 minutes or less, it may not be preferable in terms of molding processability, etc., and if the MFR is larger than 10 g / 10 minutes, the molding processability at the time of processing into a film deteriorates. It is not preferable because the impact strength of the film is difficult to develop sufficiently. In the present invention, the MFR of the ethylene / α-olefin copolymer conforms to JIS K7210 "Test method for melt mass flow rate (MFR) and melt volume flow rate (MVR) of plastic-thermoplastic plastic". , 190 ° C., 21.18N (2.16kg) value when measured under the condition of load.

The MFR can be adjusted by changing the amount of chain transfer agent (hydrogen, etc.) coexisting during ethylene polymerization or by changing the polymerization temperature, increasing the amount of hydrogen or raising the polymerization temperature. By doing so, it can be increased.

1-2. Condition (2) Density The density of the ethylene / α-olefin copolymer used in the present invention is 0.895 to 0.940 g / cm ³ , preferably 0.898 g / cm ³ or more, 0.934 g / cm ³ Less than, more preferably 0.900 to 0.930 g / cm ³ , and particularly preferably 0.910 to 0.930 g / cm ³ .

If the density is less than 0.895 g / cm ³ , the rigidity of the polyolefin resin is lowered, the product is too soft, and an unnecessarily thick design is required, which is not preferable. In addition, it is not preferable because it is very sticky and difficult to handle. Further, if the density is larger than 0.940 g / cm ^3, it is difficult to sufficiently develop the impact strength of the processed film, which is not preferable.

In the present specification, the density of the ethylene / α-olefin copolymer can be measured by JIS K7112 (1999 edition): Method A (underwater substitution method). The density can be adjusted by the amount of α-olefin during the polymerization of ethylene / α-olefin.

1-3. 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 used in the present invention is 3.0 to 5.5. It is preferably 3.2 to 5.5, more preferably 3.2 or more and less than 5.3, still more preferably 3.2 or more and less than 5.1, and particularly preferably 3.3 to 5.0. If the Mw / Mn is less than 3.0, the processability at the time of extrusion molding is inferior and it causes poor appearance such as melt fracture, and should be avoided.

If Mw / Mn is larger than 5.5, the impact strength of the ethylene / α-olefin copolymer or its film is lowered. In addition, it is not preferable because it becomes sticky easily. In the present invention, Mw and Mn of the ethylene / α-olefin copolymer are those measured by the gel permeation chromatography (GPC) method.

The conversion from the holding capacity to the molecular weight is performed using a calibration curve prepared in advance using 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 created by injecting 0.2 mL of solution dissolved in ODCB (containing 0.5 mg / mL BHT) so that each is 0.5 mg / mL. For the calibration curve, a cubic equation obtained by approximating with the least squares method is used. For conversion to molecular weight, a general-purpose calibration curve is used with reference to "Size Exclusion Chromatography" (Kyoritsu Shuppan) by Sadao Mori. The following numerical values are used for the viscosity formula [η] = K × M ^α used at that time.
PS: K = 1.38 × 10 ^-4 , α = 0.7
PE: K = 3.92 × 10 ^-4 , α = 0.733

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

The baseline and section of the obtained chromatogram are set as illustrated in FIG.

The molecular weight distribution (Mw / Mn) can be set to a predetermined range mainly by selecting a polymerization catalyst and polymerization conditions, and can be set to a predetermined range by mixing a plurality of components having different molecular weights. be able to.

1-4. Condition (4) Branch index gc
The ethylene / α-olefin copolymer used in the present invention is measured by a GPC measuring device in which a differential refractometer, a viscosity detector and a light scattering detector are further combined in addition to the above conditions (1) to (3). The minimum value (gc) of the branch index (g') between 100,000 and 1,000,000 has a molecular weight of 0.40 to 0.85, preferably 0.45 to 0.80, more preferably 0.45 to It is 0.77, particularly preferably 0.45 to 0.75. If the g _C value is larger than 0.85, the molding processability is not sufficiently exhibited, which is not preferable. When the g _C value is less than 0.40, the molding processability 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 is determined by a method for evaluating the amount of long-chain branching using the molecular weight distribution curve calculated from the following GPC-VIS measurement and the branching index (g'). is there.

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

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

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

When a long-chain branch is introduced into a polymer molecule, the radius of inertia is smaller than that of a linear polymer molecule of the same molecular weight. Since the ultimate viscosity decreases as the radius of inertia decreases, the ratio (ηbranch / ηlin) of the ultimate viscosity (ηbranch) of the branched polymer to the ultimate viscosity (ηlin) of the linear polymer having the same molecular weight decreases as the long-chain branching is introduced. It will become. Therefore, when the branching index (g'= ηbranch / ηlin) becomes a value smaller than 1, it means that a branch is introduced, and as the value becomes smaller, the introduced long-chain branch increases. Means that. In particular, in the present invention, as the absolute molecular weight obtained from MALLS, the lowest value of g'within 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 above GPC-VIS. FIG. 2 represents the branching index (g') at the molecular weight (M). Here, as the linear polymer, linear polyethylene Standard Reference Material 1475a (National Institute of Standards & Technology) can be used.

The minimum value (gc) of the branching index g'with a molecular weight of 100,000 to 1,000,000 can be set in a predetermined range mainly by selecting a polymerization catalyst and polymerization conditions, and is preferably a specific value. By using a metallocene catalyst, it can be within a predetermined range.

1-5. Condition (5) W ₂ + W ₃
The ethylene / α-olefin copolymer used in the present invention was obtained from the integrated elution curves measured by (5) cross fractional chromatography (CFC) in addition to the above conditions (1) to (4). The proportion of components whose molecular weight is equal to or greater than the weight average molecular weight of the ethylene / α-olefin copolymer (W ₂ ) and the elution amount obtained from the integrated elution curve among the components eluted at a temperature below 50 wt%. 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 of the ethylene / α-olefin copolymer among the components eluted at a temperature higher than 50 wt% is 40 weight. More than% and less than 80% by weight. It is more preferably more than 40% by weight and less than 56% by weight, particularly preferably more than 43% by weight and less than 56% by weight, still more preferably more than 45% by weight and less than 56% by weight. When the W ₂ + W ₃ value is 40% by weight or less, the proportion of the low-density high-molecular-weight component that effectively improves the impact strength of the polyolefin-based resin contained in the ethylene / α-olefin copolymer decreases, or It is not preferable because the high-density and low-density components that effectively improve the rigidity of the ethylene / α-olefin copolymer are reduced. On the other hand, when the W ₂ + W ₃ value is 80% by weight or more, the balance between the contents of the high-density low molecular weight component and the low-density high molecular weight component contained in the ethylene / α-olefin copolymer is lost, and the transparency is lost. It is not preferable because it may worsen and gel may be generated.

[CFC measurement conditions]
Cross fractionation chromatography (CFC) comprises a temperature-raising elution fractionation (TREF) section for crystalline fractionation and a gel permeation chromatography (GPC) section for molecular weight fractionation.

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

The 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: 0.4 mL
Crystallization rate: 1 ° C / min Solvent flow rate: 1 mL / min GPC measurement time: 34 minutes Stable time after GPC measurement: 5 minutes Elution temperature: 0,5,10,15,20,25,30,35,40,45 , 49, 52, 55, 58, 61, 64, 67, 70, 73, 76, 79, 82, 85, 88, 91, 94, 97, 100, 102, 120, 140

[Data analysis]
From the chromatogram of the elution component at each elution temperature obtained by the measurement, the elution amount (proportional to the area of the chromatogram) standardized so that the total sum is 100% can be obtained.
In addition, an integrated elution curve for elution temperature is calculated. The differential elution curve is obtained by differentiating this integral elution curve with temperature.

In addition, the molecular weight distribution can be obtained from each chromatogram by the following procedure. The conversion from the holding capacity to the molecular weight is performed using a calibration curve prepared in advance using 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 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 approximating with the least squares method. For conversion to molecular weight, a general-purpose calibration curve is used with reference to "Size Exclusion Chromatography" (Kyoritsu Shuppan) by Sadao Mori. The following numerical values are used for the viscosity formula [η] = K × M ^α used at that time.
PS: K = 1.38 × 10 ^-4 , α = 0.7
PE: K = 3.92 × 10 ^-4 , α = 0.733

In the chromatogram at the first elution temperature, the peak due to BHT added to the solvent and the low molecular weight side of the elution component may overlap. In that case, draw a baseline as shown in FIG. 1 to draw a molecular weight distribution. Determine the desired section. Further, as shown in Table 1 below, the weight average molecular weight of whole (overall) is obtained from the elution ratio (wt% in the table) and the weight average molecular weight (Mw in the table) at each elution temperature.

In addition, from the molecular weight distribution and elution amount at each elution temperature, the literature (S. Nakano, Y. Goto, "Development of automatic Cross Fractionation: Combination of Crystallizability Fractionation Fractionation Fractionation According to the method of .26, pp. 4217-4231 (1981)), a graph (contour diagram) showing the elution amount with respect to the elution temperature and the molecular weight as contour lines is obtained.

The following component amounts are obtained using the above contour diagram.
W ₁ : Percentage of components whose molecular weight is less than the weight average molecular weight of the ethylene / α-olefin copolymer among the components eluted at a temperature or lower at which the elution amount determined from the integral elution curve is 50 wt% or less.
W ₂ : Percentage of components whose molecular weight is equal to or greater than the weight average molecular weight of the ethylene / α-olefin copolymer among the components eluted at a temperature or lower at which the elution amount determined from the integral elution curve is 50 wt% or less.
W ₃ : Percentage of components whose molecular weight is less than the weight average molecular weight of the ethylene / α-olefin copolymer among the components eluted at a temperature higher than the temperature at which the elution amount obtained from the integral elution curve is 50 wt%.
W ₄ : Percentage of components whose molecular weight is equal to or greater than the weight average molecular weight of the ethylene / α-olefin copolymer among the components eluted at a temperature higher than the temperature at which the elution amount obtained from the integral elution curve is 50 wt%.

In addition, 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 be done.

1-6. Condition (6) W ₂ + W ₄
In the ethylene / α-olefin copolymer used in the present invention, the sum of W ₂ and W ₄ (W ₂ + W ₄ ) described in (1-5) is more than 25% by weight and less than 50% by weight, preferably. Is more than 29% by weight and less than 50% by weight, more preferably more than 29% by weight and less than 45% by weight, still more preferably 30 to 43% by weight, and particularly preferably 30 to 42% by weight. If W ₂ + W ₄ is 25% by weight or less, the high molecular weight component contained in the ethylene / α-olefin copolymer that effectively acts to improve the impact strength decreases, which is not preferable, or both ethylene / α-olefin are used. It is not preferable because the high molecular weight long-chain branched component contained in the polymer, which acts particularly effectively for improving the molding processability, is reduced, or the ratio of the high molecular weight component and the long-chain branched component is reduced, which is not preferable. On the other hand, when the W ₂ + W ₄ value is 50% by weight or more, the proportion of the high molecular weight component and the high molecular weight long chain branched component contained in the ethylene / α-olefin copolymer is large, resulting in deterioration of transparency and gel. Is not preferable because it may occur.

1-7. Condition (7) W _2- W ₄
In the ethylene / α-olefin copolymer used in the present invention, the difference between W ₂ and W ₄ (W _2- W ₄ ) described in (1-5) is more than 0% by weight and less than 20% by weight. More than 0% by weight, less than 15% by weight, more preferably more than 1% by weight, less than 15% by weight, even more preferably more than 2% by weight, less than 14% by weight, particularly preferably more than 2% by weight. It is less than 13% by weight. When W _2- W ₄ is 0% by weight or less, the low-density high-molecular-weight component contained in the ethylene / α-olefin copolymer, which acts particularly effectively on improving the impact strength, is reduced, which is not preferable. On the other hand, if W ₂ -W ₄ value is 20 wt% or more, imbalance of the amount of high density and high molecular weight component and a low-density high-molecular weight component contained in the ethylene · alpha-olefin copolymer, the transparency It is not preferable because it deteriorates and gel is generated.

1-8. Condition (8) X
The ethylene / α-olefin copolymer used in the present invention preferably has a component ratio (X) of 2 to 15% by weight, preferably 3 to 14%, which is eluted at 85 ° C. or higher by temperature elution fractionation (TREF). By weight%, more preferably 4 to 13% by weight. If the X value is larger than 15% by weight, the proportion of the low-density component contained in the ethylene / α-olefin copolymer that effectively improves the impact strength decreases, which is not preferable. If the X value is less than 2% by weight, the rigidity may deteriorate, which may not be preferable.

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

The equipment used is as follows.
(TREF section)
TREF column: 4.3 mmφ x 150 mm Stainless column Filler: 100 μm Surface-inactivated 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 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 0.1 ml
Injection inlet heating method: Aluminum heat block Measurement temperature: 140 ° C
(Detection unit)
Detector: Fixed wavelength infrared detector MIRAN 1A manufactured by FOXBORO
Detection wavelength: 3.42 μm
High temperature flow cell: Micro flow cell for LC-IR, optical path length 1.5 mm, window shape 2φ x 4 mm oval, synthetic sapphire window plate Measurement temperature: 140 ° C
(Pump section)
Liquid feed pump: SSC-3461 pump manufactured by Senshu Kagaku Co., Ltd. Measurement conditions Solvent: Ortodichlorobenzene (with 0.5 mg / mL BHT)
Sample concentration: 5 mg / mL
Sample injection volume: 0.1 mL
Solvent flow rate: 1 mL / min

1-9. Melt tension (MT)
The ethylene / α-olefin copolymer in the present invention has a high melt tension (melt tension: MT), preferably 40 mN or more. If the MT is less than 40 mN, the molding processing characteristics, particularly the stability during T-die molding and inflation molding, tend to decrease.

MT is a value determined by measuring the stress when the molten ethylene polymer is stretched at a constant speed, and can be measured under the following conditions. Capillograph 1B manufactured by Toyo Seiki Co., Ltd. is used as a testing machine, orifice: L / D = 8.0 / 2.095, inflow angle flat, set temperature: 190 ° C., piston speed: 10 mm / min, pick-up speed 4. It is measured under the condition of 0 m / min. MT can be prepared, in particular, by appropriately selecting the lowest value (gc) of the branching index (g') of polyethylene between 100,000 and 1,000,000.

2. Composition of Ethylene / α-olefin Copolymer The ethylene / α-olefin copolymer used in 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, penten-1, hexene-1, and heptene. -1, Octene-1, Nonene-1, Decene-1 and the like can be mentioned. Further, these α-olefins may be used alone or in combination of two or more. Of these, more preferable α-olefins have 3 to 8 carbon atoms, and specifically, propylene, butene-1, 3-methylbutene-1, 4-methylpentene-1, penten-1, and hexene-1. , Heptene-1, octene-1, and the like. More preferable α-olefins have 4 or 6 carbon atoms, and specific examples thereof include butene-1, 4-methylpentene-1, and hexene-1. A particularly preferred α-olefin is hexene-1. In the olefin polymerization catalyst described later, α-olefins such as 1-butene and 1-hexene by the ethylene oligomerization reaction may be produced as a by-product in the polymerization system even during ethylene homopolymerization, or “Chain”. A reaction called "-walking reaction", in which a short chain branch such as a methyl group or an ethyl group is generated in the main chain of an olefin polymer from an isomerization reaction of an active center metal-terminal carbon bond at the growing end of olefin polymerization, is well known today. In some ethylene homopolymers produced from these reactions, the short-chain branched structure may be an ethylene-based polymer that is indistinguishable from the short-chain branched structure produced by the copolymerization of α-olefins. Therefore, these by-product short-chain branches have analytically the same number of carbon atoms as the short-chain branches that occur when α-olefin as a copolymer is supplied from the outside, and these ethylene-based polymers have the above conditions. When the condition is satisfied, it is included in the ethylene / α-olefin copolymer used in the present invention.

The ratio of ethylene to α-olefin in the ethylene / α-olefin copolymer used in 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 about 0.2 to 25% by weight. Ethylene is about 80 to 99.6% by weight, α-olefin is about 0.4 to 20% by weight, and more preferably ethylene is about 82 to 99.2% by weight and α-olefin is about 0.8 to 18% by weight. More preferably, it is 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. When the ethylene content is within this range, the modification effect on the polyethylene resin is high.

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

3. 3. Method for Producing Ethylene / α-olefin Copolymer The ethylene / α-olefin copolymer used in 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 with the above-mentioned α-olefin using a catalyst for olefin polymerization.
Various types of catalysts for olefin polymerization are known today, and ethylene / α-olefin copolymers satisfying the above conditions within the range of the composition of the catalyst component and the device of polymerization conditions and post-treatment conditions. Is not limited as long as it can be prepared, but for simultaneously realizing the specific long-chain branched structure, composition distribution structure, MFR, and density of the ethylene / α-olefin copolymer used in the present invention. As an example of a suitable production method, a method using an olefin polymerization catalyst containing the specific catalyst components (A), (B) and (C) described below can be mentioned.
Catalyst component (A): A crosslinked cyclopentadienyl indenyl compound containing a transition metal element.
Catalyst component (B): A compound that reacts with the compound of component (A) to produce a cationic metallocene compound.
Catalyst component (C): Inorganic compound carrier.

3-1. Catalyst component (A)
The catalyst component (A) preferable for producing the ethylene / α-olefin copolymer used in the present invention is a crosslinked cyclopentadienyl indenyl compound containing a transition metal element, and more preferably the following general formula [ It is a metallocene compound represented by 1], and more preferably a metallocene compound represented by the following general formula [2].

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

[However, in the formula [2], M represents any transition metal of Ti, Zr or Hf. Q ¹ is showing a bonding group which crosslinks the cyclopentadienyl ring and the indenyl ring. X and Y are independently hydrogen atom, halogen atom, hydrocarbon group having 1 to 20 carbon atoms, hydrocarbon group having 1 to 20 carbon atoms including oxygen atom or nitrogen atom, and hydrocarbon group having 1 to 20 carbon atoms. A hydrocarbon-substituted amino group or an alkoxy group having 1 to 20 carbon atoms is shown. The 10 Rs are independently hydrogen atom, halogen atom, hydrocarbon group having 1 to 20 carbon atoms, silicon-containing hydrocarbon group having 1 to 18 carbon atoms including silicon number 1 to 6, and carbon number 1 to 1. 20 indicates a halogen-containing hydrocarbon group, a hydrocarbon group having 1 to 20 carbon atoms containing an oxygen atom, or a hydrocarbon group substituted silyl group having 1 to 20 carbon atoms. ]

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

[However, in the formula (1c), all explanations of abbreviations follow the description of JP2013-227271A. That is, M ^1c represents any transition metal of Ti, Zr or Hf. X ^1c and X ^2c independently have a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a hydrocarbon group having 1 to 20 carbon atoms including an oxygen atom or a nitrogen atom, and 1 to 20 carbon atoms. Indicates a hydrocarbon group-substituted amino group or an alkoxy group having 1 to 20 carbon atoms. Q ^1c and Q ^2c each independently represent a carbon atom, a silicon atom, or a germanium atom. Each of R ^1c independently represents a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, and at least two of the four R ^1c are bonded to form a ring together with Q ^1c and Q ^2c. May be good. ^mc is 0 or 1, and when ^mc is 0, Q ^1c is directly attached to a conjugated 5-membered ring containing R ^2c . R ^2c and R ^4c independently have a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a silicon-containing hydrocarbon group having 1 to 18 carbon atoms including 1 to 6 carbon atoms, and 1 carbon atom. It shows a halogen-containing hydrocarbon group of ~ 20, a hydrocarbon group having 1 to 20 carbon atoms including an oxygen atom, or a hydrocarbon group substituted silyl group having 1 to 20 carbon atoms. R ^3c represents a substituted aryl group represented by the following general formula (1-ac). ]

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

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

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 explanations of the metallocene compound represented by the above general formula (1c). Structures similar to the atoms and groups shown in 1 can be selected. Further, for R ^10c , 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 above general formula (1c) can be selected. ..

Specific examples of the metallocene compound include, but are not limited to, the compounds described in Table 1c of JP2013-227271A.

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

Two or more of the above-mentioned crosslinked cyclopentadienyl indenyl compounds can also be used as the preferred catalyst component (A) for producing the ethylene / α-olefin copolymer used in the present invention.

3-2. Catalyst component (B)
The catalyst component (B) preferable for producing the ethylene / α-olefin copolymer used in the present invention is a compound that reacts with the compound of the component (A) to produce a cationic metallocene compound, and more preferably. It is the component (B) described in JP2013-227271A (0064] to [0083], and more preferably the organoaluminum oxy compound described in the same [0065] to [0069].

3-3. Catalyst component (C)
The catalyst component (C) preferable for producing the ethylene / α-olefin copolymer used in the present invention is an inorganic compound carrier, and more preferably, JP-A-2013-227721A [0084] to [0088]. It is the described inorganic compound. At this time, the metal oxide described in the publication [0085] is preferable as the inorganic compound.

3-4. Method for Producing Catalyst for Olefin Polymerization The ethylene / α-olefin copolymer used in the present invention contains ethylene and the above-mentioned α-olefin using the catalyst for olefin polymerization containing the above catalyst components (A) to (C). It is preferably produced by a copolymerization method. The contact method of each component when obtaining the catalyst for olefin polymerization from the catalyst components (A) to (C) of the present invention is not particularly limited, and for example, the methods (I) to (III) shown below are arbitrary. It can be adopted in.

(I) A catalyst component (A) which is a crosslinked cyclopentadienyl indenyl compound containing the transition metal element and a catalyst component which is a compound which reacts with the compound of the catalyst component (A) to form a cationic metallocene compound. After contacting with (B), the catalyst component (C), which is an inorganic compound carrier, is brought into contact with the catalyst component (C).
(II) The catalyst component (A) and the catalyst component (C) are brought into contact with each other, and then the catalyst component (B) is brought into contact with the catalyst component (B).
(III) The catalyst component (B) and the catalyst component (C) are brought into contact with each other, and then the catalyst component (A) is brought into contact with the catalyst component (A).

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

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

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

In the present invention, the ratio of the catalyst component (A), the catalyst component (B) and the catalyst component (C) to be used is not particularly limited, but the following range is preferable.

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

The amount of the catalyst component (C) used is 0.0001 to 5 mmol, preferably 0.001 to 0.2 mmol, and more preferably 0.005 to 0.1 mmol per 0.0001 to 5 mmol of the transition metal in the catalyst component (A). A hit, particularly preferably 1 g per 0.01-0.04 mmol.

Further, in the present invention, the ratio of the number of moles of the metal of the catalyst component (B) to 1 g of the catalyst component (C) is preferably more than 0.005 and 0.020 (mol / g) or less, more preferably 0. More than .006 to 0.015 (mol / g) or less, more preferably more than 0.006 and 0.012 (mol / g) or less, especially preferably 0.007 to 0.010 (mol / g) Is.

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

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

Further, as a catalyst for olefin polymerization suitable for obtaining the ethylene / α-olefin copolymer used in the present invention, a catalyst component (B) and a catalyst that react with the catalyst component (A) to generate a cationic metallocene compound. As a component that also serves as the component (C), well-known layered silicates described in JP-A-05-301917, JP-A-08-127613 and the like can also be used. The layered silicate is a silicate compound having a crystal structure in which surfaces formed by ionic bonds or the like are stacked in parallel with each other with a weak bonding force. Most layered silicates are naturally produced mainly as the main component of clay minerals, but these layered silicates are not limited to those naturally produced, and may be artificial compounds.

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

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

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

3-5. Polymerization method of ethylene / α-olefin copolymer The ethylene / α-olefin copolymer used in the present invention preferably uses a catalyst for olefin polymerization prepared by the production method described in 3-4 above. It is produced by copolymerizing ethylene with the above-mentioned α-olefin.

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

In the present invention, the copolymerization reaction can be preferably carried out by a vapor phase method or a slurry method. In the case of vapor phase polymerization, ethylene or the like is polymerized in a reactor in which a gas stream of ethylene or comonomer is introduced, distributed, or circulated while substantially cutting off oxygen, water, or the like. In the case of slurry polymerization, an aliphatic 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 and the like are polymerized in the presence or absence of a solvent. Needless to say, a liquid monomer such as liquid ethylene or liquid propylene can also be used as a solvent. In the present invention, a more preferable polymerization is vapor 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, still more preferably 0.5 to 2 MPa. It is usually in the range of 5 minutes to 20 hours, preferably 30 minutes to 10 hours as the polymerization time.

The molecular weight of the produced copolymer can be adjusted to some extent by changing the polymerization conditions such as the types of the catalyst component (A) and the catalyst component (B), the molar ratio of the catalyst, and the polymerization temperature, but hydrogen is added to the polymerization reaction system. By adding the above, the molecular weight can be adjusted more effectively. Further, even if a component for removing water, a so-called scavenger, is added to the polymerization system, it can be carried out without any problem.

Examples of 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 diethylzinc and dibutylzinc, and diethyl. Organoaluminium compounds such as magnesium, dibutylmagnesium and ethylbutylmagnesium, and greenia compounds such as ethylmagnesium chloride and butylmagnesium chloride are used. Among these, triethylaluminum, triisobutylaluminum, and ethylbutylmagnesium are preferable, and triethylaluminum is particularly preferable.

The long-chain branched structure (that is, g _C ) and the comonomer copolymer composition distribution (that is, W _{1 to} W _4, etc.) of the produced copolymer are determined by the types of the catalyst component (A) and the catalyst component (B), the molar ratio of the catalyst, and the like. 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 species that easily forms a long-chain branched structure is selected, it is also possible to produce a copolymer having a small number of long-chain branched structures by, for example, lowering the polymerization temperature or increasing the ethylene pressure. Further, even if a catalyst component species having a wide molecular weight distribution or copolymerization composition distribution is selected, a copolymer having a narrow molecular weight distribution or copolymerization composition distribution can be produced by changing, for example, the catalyst component molar ratio, the polymerization conditions, or the polymerization process. It is also possible.

Even in a multi-step polymerization method in which the polymerization conditions such as hydrogen concentration, monomer amount, polymerization pressure, and polymerization temperature are different from each other, if the polymerization conditions are appropriately set, both ethylene and α-olefin used in the present invention can be used. Although it may be possible to produce a polymer, the ethylene / α-olefin copolymer used in the present invention can be produced by a one-step polymerization reaction without setting complicated polymerization operating conditions. , It is preferable because it can be manufactured more economically.

4. Resin composition for film The resin composition for film of the present invention contains the above-mentioned specific ethylene / α-olefin copolymer as a main component, and the “main component” is specifically a resin composition. It contains 60% by weight or more, preferably 70% by weight or more, more preferably 80% by weight or more, further 85% by weight or more, and particularly 98% by weight or more, or both ethylene and α-olefin as a resin component. The case where the polymer is used alone may be mentioned.

4-1. Other Resin Components Other resin components include the above ethylene / α-olefins such as high pressure method low density polyethylene (LDPE), ordinary linear low density polyethylene (LLDPE), and metallocene polyethylene produced with a single site catalyst. Examples thereof include ethylene-based resins such as other ethylene / α-olefin copolymers (B) different from the polymer (A), and other olefin-based resins.

4-2. Other formulations, etc. In the present invention, antistatic agents, antioxidants, antiblocking agents, nucleating agents, lubricants, antifogging agents, organic or inorganic pigments, as necessary, as long as the characteristics of the present invention are not impaired. Known additives such as UV protection agents, weather resistant agents, and dispersants can be added.

In the ethylene / α-olefin copolymer used in the present invention, various additives and copolymer components to be added or blended as necessary are mixed using a Henschel mixer, a super mixer, a tumbler type mixer or the like. After that, the mixture may be heat-kneaded with a uniaxial or twin-screw extruder, a kneader or the like to pelletize.

5. Molding Method The film molding method of the present invention is not particularly limited as long as it can effectively utilize the excellent processing properties and mechanical properties of the ethylene / α-olefin copolymer used in the present invention. However, preferred molding methods include various inflation molding methods, T-die film molding methods, calendar molding methods, multi-layer coextrusion molding machines, and multi-layer film molding methods by laminating treatment.

For example, when the inflation molding method is used in molding the film of the present invention, a known inflation molding machine equipped with an annular die can be used. The lip gap of the annular die provided in the inflation molding machine is preferably 0.5 to 5.0 mm, more preferably 0.7 to 4.0 mm. If the lip gap is narrower than 0.5 mm, the film surface may be roughened, and if the lip gap exceeds 5.0 mm, the moldability at high speed may be poor.

The temperature of the annular die is preferably 140 to 220 ° C, more preferably 150 to 210 ° C. Further, the blown air ring in the process of forming the inflation film is not particularly limited, but one having a plurality of blown slits is preferable. The chamber ring arranged on the upper part of the blowout ring is not particularly limited, but it is preferable to arrange two or more stages, preferably three or more stages of chamber rings. The blow-up ratio in the process of forming the inflation film is preferably in the range of 1.3 to 4.0, more preferably in the range of 1.5 to 3.0. A known bubble internal cooling device can also be used to increase the stability of the bubble.

The thickness of the film (or sheet) thus obtained is not particularly limited, and the suitable thickness varies depending on the molding method and conditions. For example, in the case of inflation molding, the film (or sheet) may be about 5 to 300 μm, and in the case of T-die molding, the film (or sheet) may be about 5 μm to 5 mm.

As for the physical properties of the film after molding, the melt tension (melt tension: MT) is in the range of 40 mN to 200 mN, preferably 40 mN to 150 mN. Within this range, it is possible to achieve both moldability and film strength. If the MT is 40 mN or less, the bubble stability during molding deteriorates, which may not be preferable. Further, if it is 200 mN or more, the film strength may be lowered, which may not be preferable. The dirt drop impact strength (DDI) is usually preferably high.

6. Applications The applications of the film (or sheet) formed from the resin composition for a film containing the ethylene / α-olefin copolymer of the present invention as a main component are specifically described as an inner bag of a paper bag and dust. Standard bags with fixed dimensions such as bags, heavy bags, wrap films, sugar bags, rice bags, oil packaging bags, food packaging films for water packaging bags such as pickles, packaging materials that require automatic filling, infusion bags , Agricultural films, nylon, polyester, metal foil, laminates with various substrates such as ethylene-vinyl acetate copolymer saponified products, standing pouches, foams and their moldings, bag-in-boxes, etc. Examples thereof include detergent containers, cooking oil containers, retort containers, medical containers, chemical containers, solvent containers, pesticide containers, infusion bags, and the like.

In the following, the present invention will be described in more detail with reference to Examples and Comparative Examples to demonstrate the excellence of the present invention and the superiority in the configuration of the present invention, but the present invention is limited by these examples. It's not a thing.

The measurement methods used in Examples and Comparative Examples are as follows. The following catalyst synthesis step and polymerization step were all carried out in a purified nitrogen atmosphere, and the solvent used was dehydrated and purified with Molecular Sieve 4A.

[Measurement method of physical properties]
(1) MFR
Measured under the condition of 190 ° C. and 21.18 N (2.16 kg) load in accordance with JIS K7210 "Test method for melt mass flow rate (MFR) and melt volume flow rate (MVR) of plastic-thermoplastic plastic". ..

(2) Density JIS K7112 (1999 edition): Measured by method A (underwater substitution method).

(3) Molecular weight distribution measured by GPC (Mw / Mn)
It was measured by gel permeation chromatography (GPC) method. The measurement conditions of GPC are as follows.
Equipment: Waters GPC (ALC / GPC 150C)
Detector: MIRAN 1A IR detector manufactured by FOXBORO (measurement wavelength: 3.42 μm)
Column: Showa Denko AD806M / S (3)
Mobile phase solvent: o-dichlorobenzene Measurement temperature: 140 ° C
Flow rate: 1.0 ml / min Injection volume: 0.2 ml
Sample Preparation: Samples are prepared with ODCB (containing 0.5 mg / mL BHT) to prepare a 1 mg / mL solution and dissolved at 140 ° C. for about 1 hour.
The baseline and section of the obtained chromatogram were taken as illustrated in FIG.
The conversion from the holding capacity to the molecular weight was performed using a calibration curve prepared in advance using 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 created by injecting 0.2 mL of solution dissolved in ODCB (containing 0.5 mg / mL BHT) so that each is 0.5 mg / mL. For the calibration curve, a cubic equation obtained by approximating with the least squares method was used. For conversion to molecular weight, a general-purpose calibration curve was used with reference to Sadao Mori's "Size Exclusion Chromatography" (Kyoritsu Shuppan). The following numerical values were 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) The minimum value (gc) of the molecular weight of the branch index (g') measured by a GPC measuring device combining a differential refractometer, a viscosity detector and a light scattering detector between 100,000 and 1,000,000.
An Alliance GPCV2000 from Waters was used as a GPC apparatus equipped with a differential refractometer (RI) and a viscosity detector (Viscometer). Further, as the light scattering detector, DAWN-E manufactured by Multi-angle Laser Light Scattering Detector (MALLS) Wyatt Technology Co., Ltd. was used. The detectors were connected in the order of MALLS, RI, and Viscometer. The mobile phase solvent is 1,2,4-triclolobene (antioxidant Irganox 1076 added at a concentration of 0.5 mg / mL). The flow rate is 1 mL / min. As the column, two GMHHR-H (S) HTs manufactured by Tosoh Corporation were connected and used. The temperature of the column, the sample injection part and each detector is 140 ° C. The sample concentration was 1 mg / mL. The injection volume (sample loop volume) is 0.2175 mL. The data processing software ASTRA (version 4.73.04) attached to MALLS was used to obtain the absolute molecular weight (M) obtained from MALLS, the squared radius of inertia (Rg), and the ultimate viscosity ([η]) obtained from Viscometer. , The calculation was performed with reference to the above-mentioned literature.
[Calculation of branch index (gC), etc.]
The branching index (g') is calculated as a ratio (ηbranch / ηlin) between the ultimate viscosity (ηbranch) obtained by measuring a sample with the Viscometer and the ultimate viscosity (ηlin) obtained by separately measuring a linear polymer. did.
As the absolute molecular weight obtained from MALLS, the lowest value of the above g'at a molecular weight of 100,000 to 1,000,000 was calculated as gC. Here, as the linear polymer, linear polyethylene Standard Reference Material 1475a (National Institute of Standards & Technology) was used.

(5) W ₂ + W ₃ , W ₂ + W ₄ , W _2- W ₄ ,
The fractionation was carried out by cross fractionation chromatography (CFC), which consisted of a temperature-increasing elution fraction (TREF) section for crystalline fractionation and a gel permeation chromatography (GPC) section for molecular weight fractionation.
That is, the polymer sample was completely dissolved in orthodichlorobenzene (ODCB) containing 0.5 mg / mL BHT at 140 ° C., and then the solution was held on a TREF column (inert) at 140 ° C. via the sample loop of the apparatus. The polymer sample was crystallized by injecting into a column packed with a glass bead carrier) and gradually cooling to a predetermined first elution temperature.
After holding at a predetermined temperature for 30 minutes, the ODCB is passed through a TREF column, so that the eluted component is injected into the GPC section to separate the molecular weight, and an infrared detector (MIRAN 1A IR detector manufactured by FOXBORO) is used. A chromatogram was obtained with a measurement wavelength of 3.42 μm). During that time, the temperature was raised to the next elution temperature in the TREF section, and after a chromatogram of the first elution temperature was obtained, the elution component at the second elution temperature was injected into the GPC section. Hereinafter, by repeating the same operation, a chromatogram of the elution component at each elution temperature was 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: 0.4 mL
Crystallization rate: 1 ° C / min Solvent flow rate: 1 mL / min GPC measurement time: 34 minutes Stable time after GPC measurement: 5 minutes Elution temperature: 0,5,10,15,20,25,30,35,40,45 , 49, 52, 55, 58, 61, 64, 67, 70, 73, 76, 79, 82, 85, 88, 91, 94, 97, 100, 102, 120, 140

From the chromatogram of the elution component at each elution temperature obtained by the data analysis measurement, the elution amount (proportional to the area of the chromatogram) standardized so that the total sum was 100% was obtained.
Moreover, the molecular weight distribution was obtained from each chromatogram by the same procedure as the above-mentioned GPC.
From the molecular weight distribution and elution amount at each elution temperature, the literature (S. Nakano, Y. Goto, "Development of automatic Cross Fractionation: Commination of Crystallizability Fractionation Fractionation and Mobility. , Pp.4217-4231 (1981)), a graph (contour diagram) showing the elution amount with respect to the elution temperature and the molecular weight as contour lines was obtained.

The following component amounts were determined using the above contour diagram.
W ₁ : Percentage of components whose molecular weight is less than the weight average molecular weight of the ethylene / α-olefin copolymer among the components eluted at a temperature or lower at which the elution amount determined from the integral elution curve is 50 wt% or less.
W ₂ : Percentage of components whose molecular weight is equal to or greater than the weight average molecular weight of the ethylene / α-olefin copolymer among the components eluted at a temperature or lower at which the elution amount determined from the integral elution curve is 50 wt% or less.
W ₃ : Percentage of components whose molecular weight is less than the weight average molecular weight of the ethylene / α-olefin copolymer among the components eluted at a temperature higher than the temperature at which the elution amount obtained from the integral elution curve is 50 wt%.
W ₄ : Percentage of components whose molecular weight is equal to or greater than the weight average molecular weight of the ethylene / α-olefin copolymer among the components eluted at a temperature higher than the temperature at which the elution amount obtained from the integral elution curve is 50 wt%.
In addition, W ₁ + W ₂ + W ₃ + W 4 = 100.

(6) Percentage of components eluted at 85 ° C. or higher by temperature elution fractionation (TREF) (X)
The sample is dissolved in orthodichlorobenzene (with 0.5 mg / mL BHT) at 140 ° C. to prepare a solution. After introducing this into a TREF column at 140 ° C., it is cooled to 100 ° C. at a temperature lowering rate of 8 ° C./min, then cooled to 40 ° C. at a temperature lowering rate of 4 ° C./min, and then at a temperature lowering rate of 1 ° C./min. Cool to -15 ° C and hold for 20 minutes. Then, the solvent ortodichlorobenzene (containing 0.5 mg / mL BHT) was flowed through the column at a flow rate of 1 mL / min, and the component dissolved in ortodichlorobenzene at −15 ° C. was eluted in the TREF column for 10 minutes. Next, the column is linearly heated to 140 ° C. at a heating rate of 100 ° C./hour to obtain an elution curve. At this time, the amount of the component eluted between 85 ° C. and 140 ° C. is defined as X (unit: wt%).

The equipment used is as follows.
(TREF section)
TREF column: 4.3 mmφ x 150 mm Stainless column Filler: 100 μm Surface-inactivated 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 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 0.1 ml
Injection inlet heating method: Aluminum heat block Measurement temperature: 140 ° C
(Detection unit)
Detector: Fixed wavelength infrared detector MIRAN 1A manufactured by FOXBORO
Detection wavelength: 3.42 μm
High temperature flow cell: Micro flow cell for LC-IR, optical path length 1.5 mm, window shape 2φ x 4 mm oval, synthetic sapphire window plate Measurement temperature: 140 ° C
(Pump section)
Liquid feed pump: SSC-3461 pump manufactured by Senshu Kagaku Co., Ltd. Measurement conditions Solvent: Ortodichlorobenzene (with 0.5 mg / mL BHT)
Sample concentration: 5 mg / mL
Sample injection volume: 0.1 mL
Solvent flow rate: 1 mL / min

(7) Melt tension (MT)
Melt tension (MT) was evaluated under the following conditions.
Capillograph 1B manufactured by Toyo Seiki Co., Ltd. is used as a testing machine, orifice: L / D = 8.0 / 2.095, inflow angle flat, set temperature: 190 ° C., piston speed: 10 mm / min, take-up speed 4.0 m. Melt tension (MT) was measured at / min.
[Inflation film molding conditions]
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: 50 mmφ
Die diameter: 75 mmφ
Extrusion amount: 15 kg / hr
Die lip gap: 1.0 mm or 3.0 mm (described in Examples)
Pick-up speed: 20.0 m / min Blow-up ratio: 2.0
Molding resin temperature: 170-190 ° C (described in Examples)
Film thickness: 30 μm
[Film evaluation method]
(1) Dirt drop impact strength (DDI)
Measured according to JIS K 7124 1A method.
[Comprehensive evaluation]
Those having a melt tension (MT) of 40 mN or less or a DDI of 130 or less were regarded as defective "x", and others were evaluated as good "○".

[Example 1]
(1) Synthesis of Crosslinked Cyclopentadienyl Indenyl Compound Dimethylsilylene (4- (4-trimethylsilyl-phenyl) -indenyl) (cyclopentadienyl) zirconium dichloride is synthesized according to the method described in JP2013-2272171. did.

(2) Synthesis of catalyst for olefin polymerization Under a nitrogen atmosphere, 30 grams of silica calcined 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 prepare a slurry. In a separately prepared 200 ml two-necked flask, put 412 mg of dimethylsilylene (4- (4-trimethylsilyl-phenyl) -indenyl) (cyclopentadienyl) zirconide dichloride synthesized in (1) above under a nitrogen atmosphere, and dehydrated toluene. After dissolving in 80.7 ml, 78.9 ml of a 20% methylaluminoxane / toluene solution manufactured by Albemar Co., Ltd. was further added at room temperature, and the mixture was stirred for 30 minutes. While heating and stirring a 500 ml three-necked flask containing a toluene slurry solution of silica in an oil bath at 40 ° C., a total amount of the toluene solution of the reaction product of the zirconosen complex and methylaluminoxane was added. After stirring at 40 ° C. for 1 hour, the mixture was allowed to settle for 15 minutes while being heated to 40 ° C. to remove 221 ml of the supernatant, and dehydrated hexane was added to stir, allow settle and remove the supernatant to reduce the toluene content in the solvent. After substituting until the content became 3% or less, the residue was distilled off under reduced pressure to obtain a powdery catalyst.

(3) Treatment of catalyst for olefin polymerization Under a nitrogen atmosphere, 32 g of the powdery 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) were placed. White P-120) 180 g of a mixed solution was added at room temperature and stirred for 10 minutes, and then distilled off under reduced pressure until the hexane content in the solvent became 5% or less at room temperature to obtain a slurry catalyst.

(4) Production of Ethylene 1-Hexene Copolymer Using the slurry catalyst obtained in (3) above, ethylene / 1-hexene vapor phase continuous copolymerization was carried out. That is, 0.027 g / hour of the powdery catalyst was placed in 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 while keeping the gas composition and temperature constant while supplying intermittently at the speed of. In addition, triethylaluminum (TEA) was supplied to the gas circulation line at 0.04 mmol / hr in order to maintain the cleanliness in the system. 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 polyethylene of 5 kg or more were 0.36 g / 10 min and 0.921 g / cm ³ , respectively. The results are shown in Table 2.
For evaluation, add 1000 ppm of antioxidant (Sumilyzer GP manufactured by Sumitomo Chemical Co., Ltd.) to the polymer and extrude it at an extrusion temperature of 180 ° C. using a single-screw extruder (USV type 30φ extruder manufactured by Union Plastics). It was pelletized.

(5) Film molding A single-layer inflation film was molded according to the following molding equipment and molding conditions.
Molding machine: Single-layer inflation molding machine (manufactured by PLACO Co., Ltd.)
Extruder: 50mmφ
Die diameter: 75 mmφ
Die lip: 3mm
Processing temperature: C1 = 180 ° C, C2-D2 = 190 ° C
Film thickness: 30 μm, 50 μm
Extrusion amount: 21 kg / hr (thickness 30 μm), 17 kg / hr (thickness 50 μm)
Pick-up speed: 27 m / min (thickness 30 μm), 14 m / min (thickness 50 μm)
BUR: 2.0 (236 mm width)

[Example 2]
Using pellets using the ethylene / 1-hexene copolymer used in Example 1, films of the same thickness were molded under the same molding conditions except that the lip gap was 1 mm, and molded in the same manner as in Example 1. The sex was evaluated.

[Comparative Example 1]
Ethylene 1-butene copolymer produced by the vapor phase method using a magnesium-titanium composite Ziegler catalyst (F37FD manufactured by Japan Polyethylene Corporation; density 0.924 g / cm ³ , MFR 1.1 g / 10 minutes) Was used to evaluate the physical properties and moldability of the material in the same manner as in Example 1. The results are shown in Table 2.

[Comparative Example 2]
Examples using an ethylene / 1-hexene copolymer (NF464N manufactured by Japan Polyethylene Corporation; density 0.918 g / cm ³ , MFR 2.1 g / 10 minutes) produced by the vapor phase method using a metallocene catalyst. Material properties and moldability were evaluated in the same manner as in 1. The results are shown in Table 2.

[Comparative Example 3]
Using low-density polyethylene manufactured by the high-pressure method (LF240 manufactured by Japan Polyethylene Corporation; density 0.924 g / cm ³ , MFR 0.7 g / 10 minutes), material properties and moldability were determined in the same manner as in Example 1. evaluated. The results are shown in Table 2.

[Comparative Example 4]
Using a commercially available metallocene polyethylene having a long-chain branch (CU5001 manufactured by Sumitomo Chemical Co., Ltd .; density 0.922 g / cm ³ , MFR 0.3 g / 10 minutes), material properties and moldability were evaluated in the same manner as in Example 1. did. The results are shown in Table 2.

The ethylene / α-olefin copolymer of Example 1 satisfies the requirements of the present invention, has a melt tension of 40 mN or more, is excellent in moldability, and is excellent in mechanical strength such as DDI. Further, by using the ethylene / α-olefin copolymer of Example 1 and setting the lip gap to 1 mm in Example 2, the mechanical strength of DDI or the like is further improved.

On the other hand, the ethylene / α-olefin copolymer of Comparative Example 1 had a branching index (g') having a molecular weight between 100,000 and 1,000,000 (gc) and a temperature elution fractionation (TREF). the proportion of components eluted at 85 ° C. or higher (X), and _W 2 -W ₄ obtained from CFC are outside the requirements of the present invention, the melt tension is poor and the moldability is less than 40 mN, the mechanical of DDI, etc. The strength was reduced. The ethylene / α-olefin copolymer of Comparative Example 1 is difficult to mold because the resin pressure at the time of molding increases when the lip gap is set to 1 mm, and the film surface becomes shark-skinned, so that the appearance deteriorates. It ends up.

The ethylene / α-olefin copolymer of Comparative Example 2 has a branching index (g') having a minimum molecular weight (gc) between 100,000 and 1,000,000, which does not meet the requirements of the present invention, and has a melt tension. It was less than 40 mN and the moldability was poor. The ethylene / α-olefin copolymer of Comparative Example 2 is difficult to mold because the resin pressure at the time of molding increases when the lip gap is set to 1 mm, and the film surface becomes shark-skinned, so that the appearance deteriorates. It ends up.

The ethylene polymer of Comparative Example 3 has a branching index (g') having a molecular weight of the lowest value between 100,000 and 1,000,000 (gc), and the ratio of components eluted at 85 ° C. or higher by temperature elution fractionation (TREF) ( X) and W ₂ + W _3, W _2- W ₄ obtained from CFC did not meet the requirements of the present invention, and the mechanical strength of DDI and the like was lowered.

Metallocene polyethylene of Comparative Example 4, the molecular weight distribution (Mw / Mn), and _W 2 -W ₄ obtained from CFC are outside the requirements of the present invention, the mechanical strength of the DDI or the like is lowered.

As is clear from the above, the resin composition for a film containing an ethylene / α-olefin copolymer as a main component of the present invention has excellent molding processing characteristics, and at the same time, a film using an ethylene / α-olefin copolymer. Is also excellent in mechanical strength such as DDI, and it is possible to provide a film economically advantageously.

Therefore, the industrial value of the resin composition for a film and the film of the present invention, which can economically provide a film having such desirable properties, is extremely large.

Claims (7)

A resin composition for a film containing 60% by weight or more in a resin composition containing an ethylene / α-olefin copolymer as a main component, which satisfies the following conditions (1) to (5).
(1) MFR exceeds 0.1 g / 10 minutes and 2.0 g / 10 minutes or less (2) Density is 0.895 to 0.940 g / cm ³ (3) Gel elution chromatography (3) The molecular weight distribution Mw / Mn measured by GPC) is 3.0 to 5.5. (4) Branching index g'measured by a GPC measuring device that combines a differential elution meter, a viscosity detector and a light scattering detector. The lowest value (gc) between 100,000 and 1,000,000 molecular weight is 0.40 to 0.77 . (5) The elution amount obtained from the integrated elution curve measured by cross-separation chromatography (CFC). Of the components eluted at a temperature of 50 wt% or less, the proportion of components having a molecular weight of more than the weight average molecular weight (W ₂ ) and the components eluted at a temperature higher than the temperature at which the elution amount obtained from the integrated elution curve is 50 wt%. The sum (W ₂ + W ₃ ) of the proportions (W ₃ ) of the components whose molecular weight is less than the weight average molecular weight is more than 40% by weight and less than 80% by weight. The resin composition for a film according to claim 1, wherein the ethylene / α-olefin copolymer further satisfies the following conditions (6) or (7).
(6) The ratio (W ₄ ) of the components whose molecular weight is equal to or higher than the weight average molecular weight among the components eluted at a temperature higher than the temperature at which the elution amount obtained from the integrated elution curves measured by W ₂ and CFC is 50 wt%. The sum (W ₂ + W ₄ ) is more than 25% by weight and less than 50% by weight. (7) Higher temperature than the temperature at which the elution amount obtained from the integrated elution curves measured by W ₂ and CFC is 50 wt%. in the difference between the percentage of the molecular weight is weight average molecular weight or more components of the eluting component _{(W 4) (W 2 -W} 4) is greater than 0 wt%, less than 20 wt% Of the ethylene · alpha-olefin copolymer, the content of the resin composition is state, and are 85 wt% or more,
The density under the condition (2) is 0.898 to 0.934 g / cm ³ , and
The resin composition for a film according to claim 1 or 2, wherein the molecular weight distribution Mw / Mn under the condition (3) is 3.2 to 5.5 . The resin composition for a film according to any one of claims 1 to 3, wherein the α-olefin in the ethylene / α-olefin copolymer has 3 to 10 carbon atoms. The resin composition for a film according to any one of claims 1 to 4, wherein the ethylene / α-olefin copolymer further satisfies the following condition (8).
(8) The ratio (X) of the components eluted at 85 ° C. or higher by the temperature rising elution fraction (TREF) is 2 to 15% by weight. Any one of claims 1 to 5, wherein the ethylene / α-olefin copolymer is produced by a catalyst for olefin polymerization containing catalyst components (A), (B) and (C). The method for producing a resin composition for a film according to.
Catalyst component (A): A crosslinked cyclopentadienyl indenyl compound containing a transition metal element.
Catalyst component (B): A compound that reacts with the compound of component (A) to produce a cationic metallocene compound.
Catalyst component (C): Inorganic compound carrier. A film comprising the resin composition for a film according to any one of claims 1 to 5.

Images