JP6152777B2 - Process for producing modified ethylene polymer - Google Patents

Description

  The present invention relates to a method for producing a modified ethylene polymer, and more particularly to a method for producing a modified ethylene polymer in which melt tension is improved by modification with an organic peroxide.

  In general, polyethylene having a linear molecular structure (linear polyethylene) is known to have poor molding processability, and as a method for improving the molding processability, a long-chain branch having a branched structure in the molecular structure. A method of blending polyethylene with linear polyethylene is known. Conventionally, high-pressure low-density polyethylene (HPLD) is well known as a typical long-chain branched polyethylene, and is widely used industrially. However, HPLD has a problem that its manufacturing process is complicated and manufacturing equipment becomes extremely expensive.

  Due to recent advances in catalyst technology, many technologies have been proposed that can produce long-chain branched polyethylene without using the high-pressure method. For example, a method of producing a long-chain branched polyethylene using a bridged bisindenyl compound (for example, see Patent Document 1) or a geometrically constrained half metallocene (see Patent Document 2) as a metallocene has been proposed.

Patent Document 3 discloses that branched polyethylene can be produced by homopolymerization of ethylene by solution polymerization using asymmetric metallocene and methylaluminoxane in which a cyclopentadienyl group and an indenyl group are carbon-bridged. Has been reported.
Furthermore, in Patent Document 4, among asymmetric metallocenes in which a cyclopentadienyl group and an indenyl group are crosslinked with a crosslinking group, there is no substituent other than the crosslinking group on the cyclopentadienyl group, and the 3-position of the indenyl group is present. Production of supported catalysts for olefin polymerization having hydrogen or a specific substituent and a specific asymmetric metallocene as an essential component, and further an ethylene polymer with improved molding processability using the supported catalyst for olefin polymerization A method has been proposed.
However, it is known that a polymer having a long chain branch has a strain hardening (strain hardening) phenomenon at the time of measurement of elongational viscosity as a typical characteristic (see Non-Patent Document 1). In the prior art using metallocene disclosed in Documents 1 to 4, etc., the strain hardening degree of elongational viscosity is insufficient, or the branching index of long chain branching is still not as high as that of HPLD. There was a need for improved structure.

  Furthermore, the present inventors have recently found a catalyst that can produce a long-chain branched polyethylene having a higher degree of strain hardening than before and a long-chain branching index close to that of a high-pressure low-density polyethylene (see Patent Document 5). ). As described above, the technology for producing polyethylene produced by using a metallocene catalyst (hereinafter, also referred to as “metallocene-based polyethylene”) having melting characteristics suitable for improvement of molding processability by catalyst technology has steadily advanced. However, there is still room for further introduction of long chain branching to improve the melt properties more than ever.

On the other hand, as a method of introducing long chain branching into polyethylene, a method of using an organic peroxide in a melt-kneading or molding process is widely known without depending on a catalyst or a polymerization technique (for example, Patent Document 6). ~ 8). By adding organic peroxide to polyethylene and heating, long chain branching can be introduced into the molecular chain by radical reaction. Generally, if the amount of peroxide added is increased, the degree of branching can be increased. it can.
However, the use of organic peroxides limits the use of the finished pellets or products in a specific field such as the color of the product, deterioration of long-term durability, deterioration of odor, and food However, the amount of peroxide cannot be increased unnecessarily, and the actual condition is that the degree of modification of the melting characteristics is limited.

Japanese Patent Laid-Open No. 08-048711 Japanese Translation of National Publication No. 07-500622 JP 05-043619 A JP 2011-137146 A Japanese Patent Application No. 2012-215715 JP-A-60-188212 JP-A-3-199244 Japanese Patent Laid-Open No. 4-130148

"Polyethylene Technology Reader" by Kazuo Matsuura and Naotaka Mikami, Industrial Research Committee, 2001

  In view of the above-mentioned problems of the prior art, the object of the present invention is to provide a modified ethylene-based heavy polymer having a sufficient number and length of long-chain branches to improve the molding processability of polyethylene, particularly metallocene-based polyethylene. It is in providing the manufacturing method of coalescence.

  As a result of intensive studies to achieve the above-mentioned problems, the present inventors have produced a transition metal catalyst having a specific range of melt flow rate (MFR), density, etc., and particularly having a specific extensional viscosity characteristic. It has been found that melt tension can be improved more efficiently than before by melting and kneading the raw material ethylene polymer together with an organic peroxide, and the present invention has been completed.

That is, according to the first aspect of the present invention, 0.00001 to 5 parts by weight of an organic peroxide is added to 100 parts by weight of a raw material ethylene polymer that satisfies the following characteristics (1) to (5). A method for producing a modified ethylene polymer is provided, which includes a step of obtaining a modified ethylene polymer having a melt tension of 10 mN or more by blending and melt-kneading.
(1) MFR = 0.1-200 g / 10 min (2) Density = 0.88-0.97 g / cm ³
(3) Mw / Mn = 2-10
(4) The minimum value of the branching index g ′ measured by a GPC measuring apparatus combining a differential refractometer, a viscosity detector, and a light scattering detector is between 0.25 and 0 in a molecular weight of 100,000 to 1,000,000. .75.
(5) A polymer produced by a polymerization reaction of ethylene using a catalyst containing a transition metal metallocene compound .

According to a second aspect of the present invention, there is provided a method for producing a modified ethylene polymer, characterized in that, in the first aspect, the raw material ethylene polymer satisfies the following characteristic (6): Is done.
(6) Logarithmic plot of elongational viscosity η (t) (unit: Pa · second) and elongation time t (unit: second) measured at a temperature of 170 ° C. and an elongation strain rate of 2.0 (unit: 1 / second) , When the inflection point of the extension viscosity due to strain hardening is observed, the maximum extension viscosity after strain hardening is ηMax (t1), and the approximate straight line of the extension viscosity before hardening is ηLinear (t1). ) / ΗLinear (t1), the strain hardening degree λmax (2.0) is 1.2-30. In addition, t1 is the time (unit: second) when the maximum extensional viscosity was observed.

  According to a third aspect of the present invention, in the first or second aspect of the invention, the modified ethylene-based heavy fuel is characterized in that the one-minute half-life decomposition temperature of the organic peroxide is 150 to 200 ° C. A method for producing a coalescence is provided.

According to a fourth invention of the present invention, in any one of the first to third inventions, the raw ethylene polymer is produced by a polymerization catalyst containing the following essential component (Ac). A method for producing the modified ethylene polymer described in the above is provided.
Component (Ac): Metallocene compound represented by the following general formula (1c)
[In formula (1c), M ^1c represents a transition metal of Ti, Zr or Hf. X ^1c and X ^2c are each independently a hydrogen atom, halogen, a hydrocarbon group having 1 to 20 carbon atoms, a hydrocarbon group having 1 to 20 carbon atoms including oxygen or nitrogen, or a hydrocarbon having 1 to 20 carbon atoms. A group-substituted amino group or an alkoxy group having 1 to 20 carbon atoms is shown. Q ^1c and Q ^2c represent a carbon atom, a silicon atom, or a germanium atom. R ^1c each independently represents a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, and two or four R ^1c , together with the bonded Q ^1c and Q ^2c , form a ring. May be. ^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, halogen, 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 oxygen or a C1-C20 hydrocarbon group-substituted silyl group. R ^3c represents a substituted aryl group represented by the following general formula (1-ac). ]
[In formula (1-ac), Y1c represents an atom of Group 14, 15 or 16 of the periodic table. R ^5c , R ^6c , R ^7c , R ^8c and R ^9c each independently represents a hydrogen atom, a chlorine atom, a bromine atom, a hydrocarbon group having 1 to 20 carbon atoms, a C 1 to 20 carbon atom containing oxygen or nitrogen. Hydrocarbon group substituted amino group having 1 to 20 carbon atoms, alkoxy group having 1 to 20 carbon atoms, silicon-containing hydrocarbon group having 1 to 18 carbon atoms including 1 to 6 silicon atoms, 1 to carbon atoms 20 halogen-containing hydrocarbon group or a C1-C20 hydrocarbon group-substituted silyl group, wherein R ^5c , R ^6c , R ^7c , R ^8c and R ^9c are bonded to each other at adjacent R's. A ring may be formed together with the atom. n ^c is 0 or 1, if ^{n c} is ^0, there is no substituent ^{R 5c} to ^{Y 1c.} p ^c is 0 or 1, if ^{p c} is ^0, the carbon atom ^{to which R 8c} and ^{R 8c} is attached is ^absent, the carbon atom to which carbon atoms and ^{R 9c which R 7c} is attached is bound is a direct bond doing. 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. ]

According to the fifth invention of the present invention, in the fourth invention, the polymerization catalyst further comprises the following essential components (B) and (C): A method for producing a polymer is provided.
Component (B): Compound that reacts with component (Ac) to form a cationic metallocene compound Component (C): Fine particle carrier

  According to the sixth invention of the present invention, in any one of the first to fifth inventions, the method for producing a modified ethylene polymer is characterized by performing melt kneading at a temperature in the range of 140 to 210 ° C. Is provided.

By the production method of the present invention, the moldability is improved, and a modified ethylene polymer into which a sufficient number and length of long chain branches are introduced can be obtained, and the moldability of polyethylene, particularly metallocene polyethylene, can be improved. Can be improved.
The modified ethylene polymer obtained by the production method of the present invention has a high melt tension (MT) relative to the fluidity (MFR) compared to the ethylene polymer produced by the prior art, It has characteristics that improve various molding processes. Therefore, for example, the fluidity can be increased while maintaining a high melt tension, the load applied to the extruder during the molding process can be reduced, and the power consumption during the molding process can be suppressed.
In addition, when an ethylene polymer is modified with an organic peroxide to obtain a specific MT, the amount of the organic peroxide added can be reduced as compared with the prior art. Since high MT can be achieved by using a small amount of organic peroxide, it is considered that the residual of the organic peroxide in the modified polyethylene can be suppressed, and the deterioration of hue and odor can also be suppressed.

FIG. 1 is a graph showing the molecular weight distribution curve calculated from GPC-VIS measurement and the relationship between the branching index (g ′) and the molecular weight (M). FIG. 2 is a graph of the extensional viscosity when an inflection point of the extensional viscosity is observed (polymerization example 1 of the example). FIG. 3 is a plot of the extensional viscosity when no inflection point of the extensional viscosity is observed. FIG. 4 is a plot diagram showing the relationship between MFR and melt tension (MT) in Examples 1 to 4 and Comparative Examples 1 to 4. FIG. 5 is a plot diagram showing the relationship between MFR and melt tension (MT) in Examples 1 to 4 and Comparative Examples 5 and 6.

  The present invention uses, as a raw material ethylene polymer, an ethylene polymer having a long chain branch produced by a polymerization catalyst containing a transition metal, and melts and kneads it together with an organic peroxide, thereby making it more than conventional. The present invention relates to a method for producing a modified ethylene polymer in which a sufficient amount of long chain branching is introduced efficiently. Hereinafter, the present invention will be described item by item.

1. Raw Material Ethylene Polymer In the present invention, the raw material ethylene polymer used for the modification by peroxide is a homopolymer of ethylene or a copolymer of ethylene and an α-olefin having 3 to 20 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, decene-1, tetradecene-1, hexadecene-1, octadecene-1, eicosene-1. 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 10 carbon atoms, specifically, propylene, butene-1, 3-methylbutene-1, 4-methylpentene-1, pentene-1, and hexene-1. , Heptene-1, octene-1, decene-1, and the like. More preferable α-olefins are those having 4 to 8 carbon atoms, specifically, butene-1, 3-methylbutene-1, 4-methylpentene-1, pentene-1, hexene-1, heptene-1, octene. -1 etc. are mentioned. Particularly preferred α-olefins are butene-1, hexene-1 and octene-1.

  The proportion of ethylene and α-olefin in the raw ethylene polymer is about 80 to about 100 wt% ethylene, about 0 to about 20 wt% α-olefin, preferably about 85 to 99.9 wt% ethylene, α-olefin is about 0.1 to 15% by weight, more preferably ethylene is about 90 to 99.5% by weight, α-olefin is about 0.5 to 10% by weight, and still more preferably ethylene is about 90 to 99% by weight. %, Α-olefin of about 1 to 10% by weight. If the ethylene content is within this range, the balance between the rigidity and impact strength of the modified ethylene polymer and the molded article is good.

  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.

2. Each characteristic of raw material ethylene polymer [characteristic (1) MFR]
The range of MFR of the raw material ethylene polymer is 0.1 to 200 g / 10 min. Here, the MFR is 190 ° C. and 21.18 N (2.16 kg) load in accordance with “Testing method for melt mass flow rate (MFR) and melt volume flow rate (MVR) of plastic-thermoplastic plastic” of JIS K7210. The value when measured under the conditions. The range of preferable MFR is 0.1-200 g / 10min, More preferably, it is 0.5-100 g / min, More preferably, it is 1-50 g / min.
When the MFR is below the above range, the MFR of the modified ethylene polymer obtained as a result of the modification by the peroxide becomes too low, and general ethylene such as film molding, sheet molding, blow molding, injection molding, etc. It is not suitable for molding of a polymer. About what exceeds the said range, even if fluidity | liquidity is too high and it modifies, the value of melt tension (MT) is not enough, and the improvement effect of a moldability is not acquired.

[Characteristic (2) Density]
The density range of the raw ethylene polymer is 0.88 to 0.97 g / cm ³ , preferably 0.89 to 0.96 g / cm ³ , more preferably 0.90 to 0.95 g / cm ³ . .
When the density is within the above range, the modified ethylene polymer and the molded article have excellent impact strength and rigidity balance and transparency. In addition, when the density is less than 0.88 g / cm ³ , the rigidity is lowered, and when the product is a thin molded body such as a film or a sheet, various problems may occur when the product is used. Inconvenience occurs in post-processing steps such as process and surface printing / bonding, etc. This is not preferable, and if the product is a thick molded body such as a pipe or various containers, the product is too soft and deforms, so it is thicker than necessary. It is not preferable because it requires a design. On the other hand, if the density is larger than 0.97 g / cm ³ , impact strength and transparency are impaired, which is not preferable.
The density is a value when measured by the density gradient tube method after heat treating the strand obtained at the time of MFR measurement at 100 ° C. for 1 hour and leaving it at room temperature for 1 hour in accordance with JIS K7112.

[Characteristic (3) Mw / Mn]
The ratio (Mw / Mn) of the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the raw material ethylene polymer is 2 to 10, preferably 2 to 6, more preferably 2.5 to 5.6. .
When Mw / Mn is less than 2, the flow characteristics are deteriorated, which is not suitable for various moldings. On the other hand, if Mw / Mn is greater than 10, the impact strength of the molded article becomes insufficient, the transparency is deteriorated, and stickiness tends to occur.

In addition, Mw and Mn of the raw material ethylene polymer are values when measured by a gel permeation chromatography (GPC) method, and the measurement conditions 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.
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. The following numerical value is used for the viscosity formula [η] = K × M ^α used for conversion to molecular weight.
PS: K = 1.38 × 10 ⁻⁴ , α = 0.7
PE: K = 3.92 × 10 ⁻⁴ , α = 0.733

[Characteristic (4) Branching index g ′]
Molecular weight (M) of the branching index g ′ measured by a GPC measuring apparatus combining a differential refractometer, a viscosity detector, and a light scattering detector of the raw ethylene polymer, the minimum value between 100,000 and 1,000,000 Is 0.25 to 0.75, preferably 0.35 to 0.73, more preferably 0.4 to 0.70.
As will be described later, g ′ is a measure of the degree of long chain branching, and g ′ can be achieved by introducing a certain amount of long chain branching into the ethylene polymer in the above range.
In Polymerization Example 1 of Examples described later, an ethylene / 1-hexene copolymer having g ′ of 0.41 was obtained. For example, the value of g ′ is

Can be prepared within the scope of the present invention by polymerizing the above monomers under the polymerization conditions described below. As a particularly preferred polymerization condition, the polymerization temperature is in the range of 60 ° C. to 90 ° C., and the pressure in the polymerization system is It is desirable to employ a range of 0.5 MPa to 1.5 MPa.

  The g ′ value of the ethylene polymer is a value measured by a long chain branching evaluation method using a molecular weight distribution curve or branching index (g ′) calculated from the following GPC-VIS measurement.

(I) 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, 6945-6952 (2000)

(Ii) Calculation of branching index (g ′), etc. The branching index (g ′) is calculated based on the intrinsic viscosity (ηbranch) obtained by measuring a sample with the above Viscometer and the intrinsic viscosity obtained separately by measuring a linear polymer (η (ηlin) and a ratio (ηbranch / ηlin).
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 inertia radius decreases, the ratio (ηbranch / ηlin) of the intrinsic viscosity (ηbranch) of the branched polymer to the intrinsic viscosity (ηlin) of the linear polymer having the same molecular weight decreases as long chain branching is introduced. 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.
FIG. 1 (a) and FIG. 1 (b) show an example of the analysis result by the GPC-VIS. FIG. 1 (a) shows the molecular weight distribution curve measured based on the molecular weight (M) obtained from MALLS and the concentration obtained from RI, and FIG. 1 (b) shows the branching index (g ′) at the molecular weight (M). Represents. Here, linear polyethylene Standard Reference Material 1475a (National Institute of Standards & Technology) was used as the linear polymer.

[Characteristic (5) Catalyst]
The raw material ethylene polymer of the present invention is a polymer produced by a polymerization reaction of ethylene using a catalyst containing a transition metal. The catalyst component for producing the raw material ethylene polymer will be described in detail in the section “3. Production method of raw material ethylene polymer” described later.
The raw material ethylene polymer in the present invention is a polymer produced by a polymerization reaction of ethylene using a catalyst containing a transition metal, and is preferably described in detail in the section of the method for producing an ethylene polymer of the present invention described later. A polymer produced by a polymerization reaction of ethylene using a catalyst containing a transition metal described in 1. More preferably, a polymer produced by a coordinated anionic polymerization reaction of ethylene using a catalyst containing a transition metal It is.
Today, various radical polymerization initiators are well known as ethylene polymerization catalysts that do not contain transition metals. Specifically, peroxides such as dialkyl peroxide compounds, alkyl hydroperoxide compounds, benzoyl peroxide, and hydrogen peroxide are used. Products, azo compounds such as azobisisobutyronitrile, azobiscyclohexanecarbonitrile, etc., but ethylene polymers produced by radical polymerization reactions using these radical polymerization initiators are included in the present invention. Absent. Even if the catalyst contains a transition metal, if the polymerization reaction proceeds substantially by radical polymerization like a so-called redox system such as hydrogen peroxide / ferrous chloride or cerium salt / alcohol, It is not regarded as a catalyst containing a transition metal in the present invention.

[Degree of strain hardening λmax (2.0)]
Moreover, it is preferable that the raw material ethylene polymer additionally satisfies the following characteristic (6).
Characteristic (6): Both elongation viscosity η (t) (unit: Pa · second) and elongation time t (unit: second) measured at a temperature of 170 ° C. and an elongation strain rate of 2.0 (unit: 1 / second) In the logarithmic plot, an inflection point of elongational viscosity due to strain hardening is observed, where ηmax (t1) is the maximum elongation viscosity after strain hardening, and ηLinear (t1) is the approximate straight line of elongational viscosity before curing. The strain hardening degree λmax (2.0) defined by (t1) / ηLinear (t1) is 1.2-30. Here, t1 is the observed time (unit: seconds) of the maximum elongational viscosity.

  Characteristic (6) is a characteristic characterizing that the raw material ethylene polymer has a specific elongational viscosity characteristic. In general, ethylene polymers include those that can be regarded as linear in molecular structure, such as general high-density polyethylene and linear low-density polyethylene, and those that have long-chain branching such as high-pressure low-density polyethylene. There is. Among these, the extensional viscosity-time profile of the linear one increases with time, and the rate of increase gradually decreases to show a steady value. On the other hand, in the case of having a long-chain branched structure, the rate of increase gradually decreases with time as in the case of a linear shape, but the rate of increase increases on the contrary when the strain is about 1, and strain hardening occurs. (For example, “Mechanical Properties I” edited by the Society of Polymer Science, Polymer Experiments Editorial Committee, Kyoritsu Shuppan Co., Ltd., 1982).

  The raw material ethylene-based polymer having a strain hardening degree λmax (2.0) of less than 1.2 is a case where the amount or length is too small or short even if it has a long chain branch. Even if the modification with the peroxide is performed, the superiority in the modification is not found as compared with a general linear ethylene polymer. On the other hand, if it exceeds 30, sufficient long chain branching already exists in the raw ethylene polymer, and if this is modified with peroxide, the fluidity is too low, May occur. That is, this characteristic (6) is an additional characteristic indicating that the raw ethylene polymer has long chain branching and is in an appropriate range, as in the above characteristic (4). A preferable range of λmax (2.0) is 2 to 20, more preferably 3 to 15.

[Λmax (2.0) / λmax (0.1)]
Moreover, it is preferable that the raw material ethylene polymer additionally satisfies the following characteristic (7).
Characteristic (7): λmax (2.0) defined in the same manner as in the above characteristic (6), and λmax (0. 0) measured in the same manner at an elongation strain rate of 0.1 (unit: 1 / second). The ratio λmax (2.0) / λmax (0.1) of 1) is 1.2 to 10.0.
This is an index indicating that the higher the strain rate is, the higher the degree of strain hardening is, and the one in which the raw ethylene polymer satisfies this characteristic can be used more suitably.

Regarding the method for measuring the strain hardening degree, the same value can be obtained in principle by any method as long as the uniaxial extensional viscosity can be measured. For example, the measurement method and the method described in well-known literature: Polymer, 42, 8663 (2001) Details of the measuring instrument are described.
In the measurement of the ethylene-based polymer according to the present invention, preferred measurement methods and measuring instruments include the following.
Measuring method:
・ Device: Ales manufactured by Rheometrics
-Jig: EXTENSIONAL VISUALITY FIXTURE, manufactured by TA Instruments
・ Measurement temperature: 170 ℃
Strain rate: 2 / second, 0.1 / second Preparation of test piece: Press-molded to produce a sheet of 18 mm × 10 mm and thickness 0.7 mm.
・ Data is captured in the range of distortion 0 to 4 at 200 points. However, the minimum capture time interval is 0.01 seconds.
The elongational viscosity is plotted on a logarithmic graph with time t (second) on the horizontal axis and elongational viscosity η (Pa · second) on the vertical axis. On the logarithmic graph, the maximum elongation viscosity until strain is 4.0 after strain hardening is ηMax (t1) (t1 is the time when the maximum elongation viscosity is shown), and the elongation viscosity before strain hardening is When the approximate straight line is ηLinear (t), a value calculated as ηMax (t1) / ηLinear (t1) is defined as strain hardening degree (λmax). The presence / absence of strain hardening is determined by whether or not there is an inflection point at which the extensional viscosity changes from an upward convex curve to a downward convex curve over time. The determination method is as follows in detail.
In this measurement method, since the extensional viscosity is obtained as a discrete value with respect to time, in order to obtain the change rate of the slope of the extensional viscosity curve (the inclination of the logarithm of the extensional viscosity to the logarithm of time) Use the average method. For example, there is a method in which the slopes of adjacent data are obtained, and a moving average of several points (4 points are recommended. If the data is rough, it may be changed to 2 to 10 points as appropriate). The rate of change of this slope with respect to time is obtained, and in the region where the amount of strain (= strain rate × time) is 0.5 to 1.5, a positive value is obtained from a negative value (that is, an upwardly convex curve) with time. When there is a point that changes to a curved line (that is, a downwardly convex curve), it is determined that there is an inflection point, and that time is the strain hardening start time. When there are a plurality of such points that change from negative to positive, such as when the data is rough, the point where the strain amount is closer to 1 is set as the strain hardening start time. The approximate straight line of the extensional viscosity before strain hardening is the time before the strain hardening start point, and the slope at the time when the slope after averaging at each time is minimum is adopted as the slope of the approximate straight line. Assume that the intercept is obtained so as to pass through the point.
2 and 3 are typical plots of elongational viscosity. FIG. 2 shows a case where an inflection point of elongational viscosity is observed, and ηMax (t1) and ηLinear (t) are shown in the figure. FIG. 3 shows a case where an inflection point of elongational viscosity is not observed.

[W- ₁₅ ]
Furthermore, it is preferable that the raw material ethylene polymer additionally satisfies the following property (8).
Characteristic (8): In temperature-temperature elution fractionation (TREF) measurement using an orthodichlorobenzene solvent, the content (W- ₁₅ : unit wt%) of a component eluted at -15 [deg.] C. is 2.0 wt% or less.
The upper limit of the W- ₁₅ value is preferably 1.1 wt% or less, more preferably 0.6 wt% or less, still more preferably 0.5 wt% or less, and particularly preferably 0.4 wt% or less. Most preferably, it is 0.3 wt% or less. The lower limit of W- ₁₅ is that it is not detected, and is preferably 0.0 wt%. Within this range, impact resistance and transparency are better.

The conditions for TREF measurement are as follows.
A sample is dissolved in orthodichlorobenzene (containing 0.5 mg / mL BHT) at 140 ° C. to obtain a solution. This is introduced into a 140 ° C. TREF column, cooled to 100 ° C. at a rate of 8 ° C./min, subsequently cooled to −15 ° C. at a rate of 4 ° C./min, and held for 60 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 the component eluted at −15 ° C. was defined as the amount of soluble matter at −15 ° C., that is, W- ₁₅ (unit: wt%).
Equipment (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

3. Production Method of Raw Material Ethylene Polymer As a production method of the raw material ethylene polymer used in the present invention, an ethylene polymer satisfying the above characteristics (1) to (5), preferably the characteristics (6) to (8). However, it is preferably produced using an olefin polymerization catalyst described below.
Hereinafter, each component contained in the olefin polymerization catalyst suitably used for the production of the raw material ethylene polymer, the olefin polymerization catalyst, and the production method of the raw material ethylene polymer polymer using the olefin polymerization catalyst, Each item will be described in detail.

(1) Metallocene compound The starting ethylene polymer used in the present invention is preferably produced by an olefin polymerization catalyst containing the following essential component (Ac).
Component (Ac): Metallocene compound represented by the following general formula (1c)

[In formula (1c), M ^1c represents a transition metal of Ti, Zr, or Hf. X ^1c and X ^2c are each independently a hydrogen atom, halogen, a hydrocarbon group having 1 to 20 carbon atoms, a hydrocarbon group having 1 to 20 carbon atoms including oxygen or nitrogen, or a hydrocarbon having 1 to 20 carbon atoms. A group-substituted amino group or an alkoxy group having 1 to 20 carbon atoms is shown. Q ^1c and Q ^2c 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 four R ^{1c s} may form a ring together with the bonded Q ^1c and Q ^2c. . ^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, halogen, 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 oxygen or a C1-C20 hydrocarbon group-substituted silyl group. R ^3c represents a substituted aryl group represented by the following general formula (1-ac).

(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 hydrogen. Atom, chlorine atom, bromine atom, hydrocarbon group having 1 to 20 carbon atoms, hydrocarbon group having 1 to 20 carbon atoms including oxygen or nitrogen, substituted amino group having 1 to 20 carbon atoms, 1 to carbon atoms 20 alkoxy groups, silicon-containing hydrocarbon groups having 1 to 18 carbon atoms including 1 to 6 silicon atoms, halogen-containing hydrocarbon groups having 1 to 20 carbon atoms, or hydrocarbon group-substituted silyl groups having 1 to 20 carbon atoms. R ^5c , R ^6c , R ^7c , R ^8c, and R ^9c may form a ring together with the atoms bonded to each other at adjacent R's, and n ^c is 0 or 1 If ^{n c} is ^0, there is a substituent ^{R 5c} to ^{Y 1c} No .p ^c is 0 or 1, if ^{p c} is ^0, the carbon atom ^{to which R 8c} and ^{R 8c} is attached is ^absent, the carbon atom to which carbon atoms and ^{R 9c which R 7c} is attached is attached is 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 metallocene compound represented by the general formula (1c) is characterized in that the cyclopentadienyl ring and the indenyl ring are cross-linked and further has a specific substituent at the 4-position of the indenyl ring. Specific examples are listed below.

In the general formula (1c), M ^{1c of the} metallocene compound represents Ti, Zr, or Hf. M ^1c of the tarocene compound preferably represents Zr or Hf, and more preferably represents Zr.
X ^1c and X ^2c are each independently a hydrogen atom, halogen, a hydrocarbon group having 1 to 20 carbon atoms, a hydrocarbon group having 1 to 20 carbon atoms including oxygen or nitrogen, or a carbon atom having 1 to 20 carbon atoms. A hydrocarbon group-substituted amino group or an alkoxy group having 1 to 20 carbon atoms is shown. Specific examples of X ^1c and X ^2c include hydrogen atom, chlorine atom, bromine atom, iodine atom, or methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group. , T-butyl group, n-pentyl group, neopentyl group, cyclopentyl group, n-hexyl group, cyclohexyl group, phenyl group, benzyl group, methoxymethyl group, ethoxymethyl group, n-propoxymethyl group, i-propoxymethyl group N-butoxymethyl group, i-butoxymethyl group, t-butoxymethyl group, methoxyethyl group, ethoxyethyl group, acetyl group, 1-oxopropyl group, 1-oxo-n-butyl group, 2-methyl-1 -Oxopropyl group, 2,2-dimethyl-1-oxo-propyl group, phenylacetyl group, diphenylacetyl group, benzoy Group, 2-methoxyphenyl group, 3-methoxyphenyl group, 4-methoxyphenyl group, 2-furyl group, 2-tetrahydrofuryl group, dimethylaminomethyl group, diethylaminomethyl group, di-propylaminomethyl group, bis ( Dimethylamino) methyl group, bis (dii-propylamino) methyl group, (dimethylamino) (phenyl) methyl group, methylimino group, ethylimino group, 1- (methylimino) ethyl group, 1- (phenylimino) ethyl group, 1-[(phenylmethyl) imino] ethyl group, methoxy group, ethoxy group, n-propoxy group, i-propoxy group, n-butoxy group, i-butoxy group, t-butoxy group, phenoxy group, dimethylamino group, Diethylamino group, di-n-propylamino group, di-i-propylamino group, di-n-butylamino group , Di i-butylamino group, di-t-butylamino group, diphenylamino group and the like.
Specific examples of preferable X ^1c and X ^2c include chlorine atom, bromine atom, methyl group, n-butyl group, i-butyl group, methoxy group, ethoxy group, i-propoxy group, n-butoxy group, phenoxy group, Examples thereof include a dimethylamino group and a di i-propylamino group. Among these specific examples, a chlorine atom, a methyl group, and a dimethylamino group are particularly preferable.

Q ^1c and Q ^2c represent a carbon atom, a silicon atom, or a germanium atom. Q ^1c and Q ^2c are preferably a carbon atom or a silicon atom, and more preferably a silicon atom.

In addition, each R ^1c independently represents a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms. Specific examples of R ^1c include a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, i -Propyl group, n-butyl group, i-butyl group, t-butyl group, n-pentyl group, neopentyl group, cyclopentyl group, n-hexyl group, cyclohexyl group, phenyl group and the like.
Four R ^{1c s} may form a ring together with Q ^1c and Q ^2c to which R ^1c is bonded, but when R ^1c forms a ring together with Q ^1c and Q ^2c , Examples include a cyclobutylidene group, a cyclopentylidene group, a cyclohexylidene group, a silacyclobutyl group, a silacyclopentyl group, and a silacyclohexyl group.
Specific examples of preferable R ^1c include a hydrogen atom, a methyl group, an ethyl group, a phenyl group, an ethylene group, and a cyclobutylidene group when Q ^1c and / or Q ^2c are carbon atoms, and Q ^1c or / When Q ^2c is a silicon atom, examples thereof include a methyl group, an ethyl group, a phenyl group, and a silacyclobutyl group.

R ^2c and R ^4c are each independently a hydrogen atom, halogen, 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 a carbon number. 1 to 20 halogen-containing hydrocarbon group, an oxygen-containing C1-20 hydrocarbon group or a C1-20 hydrocarbon group-substituted silyl group. Specific examples of R ^2c and R ^4c include hydrogen atom, chlorine atom, bromine atom, iodine atom, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, t -Butyl group, n-pentyl group, neopentyl group, cyclopentyl group, n-hexyl group, cyclohexyl group, phenyl group, benzyl group, 2-methylphenyl group, 3-methylphenyl group, 4-methylphenyl group, 3,5 -Dimethylphenyl group, 4-t-butylphenyl group, 3,5-di-t-butylphenyl group, bis (trimethylsilyl) methyl group, bis (t-butyldimethylsilyl) methyl group, bromomethyl group, chloromethyl group, 2-chloroethyl group, 2-bromoethyl group, 2-bromopropyl group, 3-bromopropyl group, 2-bromocyclopentyl group, 2,3-dibro Cyclopentyl group, 2-bromo-3-iodocyclopentyl group, 2,3-dibromocyclohexyl group, 2-chloro-3-iodocyclohexyl group, 2-chlorophenyl group, 4-chlorophenyl group, 2,3,4,5,6 -Pentafluorophenyl group, 4-trifluoromethylphenyl group, furyl group, tetrahydrofuryl group, 2-methylfuryl group, trimethylsilyl group, tri-t-butylsilyl group, di-t-butylmethylsilyl group, t-butyldimethylsilyl group , Triphenylsilyl group, diphenylmethylsilyl group, phenyldimethylsilyl group and the like.

Further, any one of R ^2c and R ^4c is a hydrocarbon group having 1 to 20 carbon atoms, a silicon-containing hydrocarbon group having 1 to 18 carbon atoms including 1 to 6 silicon atoms, and a halogen-containing carbon atom having 1 to 20 carbon atoms. A hydrogen group, a C1-C20 hydrocarbon group containing oxygen, or a C1-C20 hydrocarbon group-substituted silyl group is particularly preferable because the polymerization activity is increased.
Preferable specific examples of R ^2c and R ^4c include hydrogen atom, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, t-butyl group, n-pentyl group and n-hexyl group. Cyclohexyl group, phenyl group, 2-methylfuryl group, and trimethylsilyl group. Among these specific examples, a hydrogen atom, a methyl group, an n-butyl group, a t-butyl group, a phenyl group, and a trimethylsilyl group are more preferable, and a hydrogen atom, a methyl group, a t-butyl group, a phenyl group, and a trimethylsilyl group are particularly preferable. preferable.

The substituent R ^3c represents a substituted aryl group having a structure represented by the above general formula (1-ac), preferably a phenyl (Ph) group having a specific substituent, or a furyl group or a thienyl group. .
Specifically, 4-trimethylsilylphenyl group, 4- (t-butyldimethylsilyl) phenyl group, 3,5-bistrimethylsilylphenyl group, 4-chlorophenyl group, 4-bromophenyl group, 3,5-dichlorophenyl group, 2,4,6-trichlorophenyl group, 4-methoxyphenyl group, 4-ethoxyphenyl group, 4-isopropoxyphenyl group, 4-n-butoxyphenyl group, 2-furyl group, 2- (5-methyl) furyl Group, 2- (5-t-butyl) furyl group, 2- (5-trimethylsilyl) furyl group, 2- (4,5-dimethyl) furyl group, 2-benzofuryl group, 2-thienyl group, 2- (5 -Methyl) thienyl group, 2- (5-t-butyl) thienyl group, 2- (5-trimethylsilyl) thienyl group, 2- (4,5-dimethyl) thienyl group, etc. And the like.

In general formula (1c), ^mc is 0 or 1, and when ^mc is 0, Q ^1c is directly bonded to a conjugated 5-membered ring containing R ^2c .

  Among the metallocene compounds represented by the general formula (1c), those represented by the following general formula (2c) are preferable.

In the metallocene compound represented by the 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 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). .

  Among the metallocene compounds represented by the above general formula (1c), those represented by the following general formula (3c) are also preferable as in the general formula (2c).

In the metallocene compound represented by the above general formula (3c), M ^1c , X ^1c , X ^2c , Q ^1c , R ^1c , R ^2c and R ^4c are 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 ^12c , R ^13c, and R ^14c are the same as the atoms and groups of R ^5c , R ^6c , R ^7c , R ^8c , and R ^9c shown in the description of the metallocene compound represented by the general formula (1c). A structure can be selected. Z ^1c represents an oxygen atom or a sulfur atom.

(2) Catalyst for Polymerization of Raw Material Ethylene Polymer When producing a raw material ethylene polymer, the olefin polymerization catalyst preferably used may contain the following essential components (Ac), (B) and (C). preferable.
Component (Ac): Metallocene compound represented by the above general formula (1c) Component (B): Compound that reacts with the metallocene compound of component (Ac) to form a cationic metallocene compound Component (C): Fine particle carrier

(I) Component (Ac)
The catalyst for olefin polymerization suitably used in the present invention comprises, as an essential component (Ac), a metallocene compound represented by the above general formula (1c), preferably a metallocene represented by the above general formulas (2c) and (3c). Use compounds. In addition, as the component (Ac), two or more kinds of metallocene compounds represented by the above general formulas (1c), (2c), and (3c) can be used.

(Ii) Component (B)
The catalyst for olefin polymerization suitably used in the present invention contains, as an essential component, a component (B) that is a compound that reacts with the component (Ac) to form a cationic metallocene compound, in addition to the component (Ac).

An organic aluminum oxy compound is mentioned as one of the components (B).
The organoaluminum oxy compound has an Al—O—Al bond in the molecule, and the number of bonds is usually in the range of 1 to 100, preferably 1 to 50. Such an organoaluminum oxy compound is usually a product obtained by reacting an organoaluminum compound with water.
The reaction between organoaluminum and water is usually carried out in an inert hydrocarbon (solvent). As the inert hydrocarbon, aliphatic hydrocarbons such as pentane, hexane, heptane, cyclohexane, methylcyclohexane, benzene, toluene and xylene, alicyclic hydrocarbons and aromatic hydrocarbons can be used. Preference is given to using aromatic hydrocarbons.

As the organoaluminum compound used for the preparation of the organoaluminum oxy compound, any compound represented by the following general formula (5) can be used, but trialkylaluminum is preferably used.
R ⁶ tAlX ³ 3-t Formula (5)
(In the formula (5), R ⁶ represents a hydrocarbon group such as an alkyl group, alkenyl group, aryl group or aralkyl group having 1 to 18 carbon atoms, preferably 1 to 12 carbon atoms, and X ³ represents a hydrogen atom or a halogen atom. Represents an atom, and t represents an integer of 1 ≦ t ≦ 3.)

The alkyl group of the trialkylaluminum may be any of methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, pentyl group, hexyl group, octyl group, decyl group, dodecyl group, etc. It is particularly preferred that
Two or more of the above organoaluminum compounds can be mixed and used.

The reaction ratio (water / Al molar ratio) between water and the organoaluminum compound is preferably 0.25 / 1 to 1.2 / 1, particularly preferably 0.5 / 1 to 1/1, and the reaction temperature is Usually, it is -70-100 degreeC, Preferably it exists in the range of -20-20 degreeC. The reaction time is usually selected in the range of 5 minutes to 24 hours, preferably 10 minutes to 5 hours. As water required for the reaction, not only mere water but also crystal water contained in copper sulfate hydrate, aluminum sulfate hydrate and the like and components capable of generating water in the reaction system can be used. Of the organoaluminum oxy compounds described above, those obtained by reacting alkylaluminum with water are usually called aluminoxanes, particularly methylaluminoxane (including those substantially consisting of methylaluminoxane (MAO)). Is suitable as an organoaluminum oxy compound.
Of course, as the organoaluminum oxy compound, two or more of the above organoaluminum oxy compounds may be used in combination, and a solution obtained by dispersing or dispersing the organoaluminum oxy compound in the above-described inert hydrocarbon solvent. You may use.

  When an organoaluminum oxy compound is used as the component (B) for the olefin polymerization catalyst, the degree of strain hardening (λmax) of the resulting ethylene polymer increases, or Mz / Mw (which is a measure of the high molecular weight component content). Here, Mz represents a Z average molecular weight measured by GPC, and Mw represents the same weight average molecular weight. This is preferable because the moldability is further improved.

  Other specific examples of the component (B) include borane compounds and borate compounds. More specifically, the borane compound is represented by triphenylborane, tri (o-tolyl) borane, tri (p-tolyl) borane, tri (m-tolyl) borane, tri (o-fluorophenyl) borane, tris ( p-fluorophenyl) borane, tris (m-fluorophenyl) borane, tris (2,5-difluorophenyl) borane, tris (3,5-difluorophenyl) borane, tris (4-trifluoromethylphenyl) borane, tris (3,5-ditrifluoromethylphenyl) borane, tris (2,6-ditrifluoromethylphenyl) borane, tris (pentafluorophenyl) borane, tris (perfluoronaphthyl) borane, tris (perfluorobiphenyl), tris ( Perfluoroanthryl) borane, tris (perfluorobi) Fuchiru) such as borane and the like.

  Among these, tris (3,5-ditrifluoromethylphenyl) borane, tris (2,6-ditrifluoromethylphenyl) borane, tris (pentafluorophenyl) borane, tris (perfluoronaphthyl) borane, tris (perfluoro) Biphenyl) borane, tris (perfluoroanthryl) borane, and tris (perfluorobinaphthyl) borane are more preferred, and tris (2,6-ditrifluoromethylphenyl) borane, tris (pentafluorophenyl) borane, tris ( Perfluoronaphthyl) borane and tris (perfluorobiphenyl) borane are exemplified as preferred compounds.

When the borate compound is specifically represented, the first example is a compound represented by the following general formula (6).
^{[L 1 -H] + [BR} 7 R 8 X 4 X 5] - ··· formula (6)

In Formula (6), L ¹ is a neutral Lewis base, H is a hydrogen atom, and [L ¹ -H] is a Bronsted acid such as ammonium, anilinium, phosphonium or the like. Examples of ammonium include trialkylammonium such as trimethylammonium, triethylammonium, tripropylammonium, tributylammonium, and tri (n-butyl) ammonium, and dialkylammonium such as di (n-propyl) ammonium and dicyclohexylammonium.

  Examples of anilinium include N, N-dialkylanilinium such as N, N-dimethylanilinium, N, N-diethylanilinium, N, N-2,4,6-pentamethylanilinium. Furthermore, examples of the phosphonium include triarylphosphonium, tributylphosphonium, triarylphosphonium such as tri (methylphenyl) phosphonium, tri (dimethylphenyl) phosphonium, and trialkylphosphonium.

In formula (6), R ⁷ and R ⁸ are the same or different aromatic or substituted aromatic hydrocarbon groups containing 6 to 20, preferably 6 to 16 carbon atoms, and are linked to each other by a bridging group. As the substituent of the substituted aromatic hydrocarbon group, an alkyl group typified by a methyl group, an ethyl group, a propyl group, an isopropyl group or the like, or a halogen such as fluorine, chlorine, bromine or iodine is preferable. Further, X ⁴ and X ⁵ are a hydride group, a halide group, a hydrocarbon group containing 1 to 20 carbon atoms, a substituted carbon atom containing 1 to 20 carbon atoms in which one or more hydrogen atoms are replaced by halogen atoms. It is a hydrogen group.

  Specific examples of the compound represented by the general formula (6) include tributylammonium tetra (pentafluorophenyl) borate, tributylammonium tetra (2,6-ditrifluoromethylphenyl) borate, tributylammonium tetra (3,5- Ditrifluoromethylphenyl) borate, tributylammonium tetra (2,6-difluorophenyl) borate, tributylammonium tetra (perfluoronaphthyl) borate, dimethylanilinium tetra (pentafluorophenyl) borate, dimethylanilinium tetra (2,6- Ditrifluoromethylphenyl) borate, dimethylanilinium tetra (3,5-ditrifluoromethylphenyl) borate, dimethylanilinium tetra (2,6-difluoropheny) ) Borate, dimethylanilinium tetra (perfluoronaphthyl) borate, triphenylphosphonium tetra (pentafluorophenyl) borate, triphenylphosphonium tetra (2,6-ditrifluoromethylphenyl) borate, triphenylphosphonium tetra (3,5- Ditrifluoromethylphenyl) borate, triphenylphosphonium tetra (2,6-difluorophenyl) borate, triphenylphosphonium tetra (perfluoronaphthyl) borate, trimethylammonium tetra (2,6-ditrifluoromethylphenyl) borate, triethylammonium tetra (Pentafluorophenyl) borate, triethylammonium tetra (2,6-ditrifluoromethylphenyl) borate, triethyla Monium tetra (perfluoronaphthyl) borate, tripropylammonium tetra (pentafluorophenyl) borate, tripropylammonium tetra (2,6-ditrifluoromethylphenyl) borate, tripropylammonium tetra (perfluoronaphthyl) borate, di (1 -Propyl) ammonium tetra (pentafluorophenyl) borate, dicyclohexylammonium tetraphenylborate and the like.

  Among these, tributylammonium tetra (pentafluorophenyl) borate, tributylammonium tetra (2,6-ditrifluoromethylphenyl) borate, tributylammonium tetra (3,5-ditrifluoromethylphenyl) borate, tributylammonium tetra (perfluoro) Naphthyl) borate, dimethylanilinium tetra (pentafluorophenyl) borate, dimethylaniliniumtetra (2,6-ditrifluoromethylphenyl) borate, dimethylaniliniumtetra (3,5-ditrifluoromethylphenyl) borate, dimethylanilinium Tetra (perfluoronaphthyl) borate is preferred.

Moreover, the 2nd example of a borate compound is represented by following General formula (7).
^{[L 2] + [BR 7} R 8 X 4 X 5] - ··· (7)

In the formula (7), L ² represents carbocation, methyl cation, ethyl cation, propyl cation, isopropyl cation, butyl cation, isobutyl cation, tert-butyl cation, pentyl cation, tropinium cation, benzyl cation, trityl cation, sodium. A cation, a proton, etc. are mentioned. R ⁷ , R ⁸ , X ⁴ and X ⁵ are the same as defined in the general formula (6).

Specific examples of the compound include trityl tetraphenyl borate, trityl tetra (o-tolyl) borate, trityl tetra (p-tolyl) borate, trityl tetra (m-tolyl) borate, trityl tetra (o-fluorophenyl) borate, Trityltetra (p-fluorophenyl) borate, trityltetra (m-fluorophenyl) borate, trityltetra (3,5-difluorophenyl) borate, trityltetra (pentafluorophenyl) borate, trityltetra (2,6-ditrifluoro) Methylphenyl) borate, trityltetra (3,5-ditrifluoromethylphenyl) borate, trityltetra (perfluoronaphthyl) borate, tropiniumtetraphenylborate, tropiniumtetra (o-tolyl) Rate, tropinium tetra (p-tolyl) borate, tropinium tetra (m-tolyl) borate, tropinium tetra (o-fluorophenyl) borate, tropinium tetra (p-fluorophenyl) borate, tropinium tetra (m- Fluorophenyl) borate, tropinium tetra (3,5-difluorophenyl) borate, tropinium tetra (pentafluorophenyl) borate, tropinium tetra (2,6-ditrifluoromethylphenyl) borate, tropinium tetra (3,5 - ditrifluoromethylphenyl) borate, tropicity tetra (perfluoro-naphthyl) _{borate, NaBPh 4, NaB (o-} CH 3 -Ph) 4, NaB (p-CH 3 -Ph) 4, NaB (m-CH 3 - Ph) ₄ , Na _{B (o-F-Ph)} 4, NaB (p-F-Ph) 4, NaB (m-F-Ph) 4, NaB (3,5-F 2 -Ph) 4, NaB (C 6 F 5) _{4, NaB (2,6- (CF 3} ) 2 -Ph) 4, NaB (3,5- (CF 3) 2 -Ph) 4, NaB (C 10 F 7) 4, HBPh 4 · 2 diethyl ether, _{HB (3,5-F 2 -Ph)} 4 · 2 diethyl _{ether, HB (C 6 F 5)} 4 · 2 diethyl _{ether, HB (2,6- (CF 3)} 2 -Ph) 4 · 2 diethyl ether, HB (3,5- (CF ₃ ) ₂ -Ph) ₄ · 2 diethyl ether and HB (C ₁₀ H ₇ ) ₄ · 2 diethyl ether can be exemplified.

Among these, trityltetra (pentafluorophenyl) borate, trityltetra (2,6-ditrifluoromethylphenyl) borate, trityltetra (3,5-ditrifluoromethylphenyl) borate, trityltetra (perfluoronaphthyl) borate, Tropinium tetra (pentafluorophenyl) borate, tropinium tetra (2,6-ditrifluoromethylphenyl) borate, tropinium tetra (3,5-ditrifluoromethylphenyl) borate, tropinium tetra (perfluoronaphthyl) borate, _{NaB (C 6 F 5) 4} , NaB (2,6- (CF 3) 2 -Ph) 4, NaB (3,5- (CF 3) 2 -Ph) 4, NaB (C 10 F 7) 4, _{HB (C 6 F 5) 4} · 2 diethyl ether _{, HB (2,6- (CF 3)} 2 -Ph) 4 · 2 diethyl _{ether, HB (3,5- (CF 3)} 2 -Ph) 4 · 2 diethyl _{ether, HB (C 10 H 7)} 4 · 2 diethyl ether is preferred.

More preferably, among these, trityltetra (pentafluorophenyl) borate, trityltetra (2,6-ditrifluoromethylphenyl) borate, tropiniumtetra (pentafluorophenyl) borate, tropiniumtetra (2,6-ditrifluoro) Methylphenyl) borate, NaB (C ₆ F ₅ ) ₄ , NaB (2,6- (CF ₃ ) ₂ -Ph) ₄ , HB (C ₆ F ₅ ) ₄ · 2 diethyl ether, HB (2,6- ( _{CF 3) 2 -Ph) 4 ·} 2 diethyl _{ether, HB (3,5- (CF 3)} 2 -Ph) 4 · 2 diethyl _{ether, HB (C 10 H 7) 4} · 2 diethyl ether.

  When a borane compound or a borate compound is used as the component (B), the polymerization activity and the copolymerizability are increased, so that the productivity of an ethylene polymer having a long chain branch is improved. Further, as the component (B) of the olefin polymerization catalyst, a mixture of the organoaluminum oxy compound and the borane compound or borate compound can be used. Further, two or more of the above borane compounds and borate compounds can be used in combination.

(Iii) Component (C)
Examples of the component (C) that is a fine particle carrier include an inorganic carrier, a particulate polymer carrier, and a mixture thereof. As the inorganic carrier, a metal, a metal oxide, a metal chloride, a metal carbonate, a carbonaceous material, or a mixture thereof can be used.
Suitable metals that can be used for the inorganic carrier include, for example, iron, aluminum, nickel and the like.

Further, as the metal oxide, either alone oxide or composite oxide of the Periodic Table 1-14 Group elements include, for _{example, SiO 2, Al 2 O 3} , MgO, CaO, B 2 O 3, TiO 2, _{ZrO 2, Fe 2 O 3,} Al 2 O 3 · MgO, Al 2 O 3 · CaO, Al 2 O 3 · SiO 2, Al 2 O 3 · MgO · CaO, Al 2 O 3 · MgO · SiO 2, Al Examples include various natural or synthetic single oxides or composite oxides such as ₂ O ₃ .CuO, Al ₂ O ₃ .Fe ₂ O ₃ , Al ₂ O ₃ .NiO, and SiO ₂ .MgO. Here, the above formula is not a molecular formula but represents only the composition, and the structure and component ratio of the composite oxide used in the present invention are not particularly limited. In addition, the metal oxide used in the present invention may absorb a small amount of moisture or may contain a small amount of impurities.

As the metal chloride, for example, an alkali metal or alkaline earth metal chloride is preferable, and specifically, MgCl ₂ , CaCl _{2 and the} like are particularly preferable. As the metal carbonate, carbonates of alkali metals and alkaline earth metals are preferable, and specific examples include magnesium carbonate, calcium carbonate, barium carbonate and the like. Examples of the carbonaceous material include carbon black and activated carbon. Any of the above inorganic carriers can be suitably used in the present invention, but the use of metal oxides, silica, alumina and the like is particularly preferable.

These inorganic carriers are usually calcined in air or an inert gas such as nitrogen or argon at 200 to 800 ° C., preferably 400 to 600 ° C., and the amount of surface hydroxyl groups is 0.8 to 1.5 mmol / g. It is preferable to adjust to use. The properties of these inorganic carriers are not particularly limited, but usually the average particle size is 5 to 200 μm, preferably 10 to 150 μm, the average pore size is 20 to 1000 mm, preferably 50 to 500 mm, and the specific surface area is 150 to 1000 m. ² / g, preferably 200-700 m ² / g, pore volume 0.3-2.5 cm ³ / g, preferably 0.5-2.0 cm ³ / g, apparent specific gravity 0.20-0 It is preferred to use an inorganic carrier having a density of .50 g / cm ³ , preferably 0.25 to 0.45 g / cm ³ .

  Of course, the above-mentioned inorganic carriers can be used as they are, but as a pretreatment, these carriers are trimethylaluminum, triethylaluminum, triisobutylaluminum, trihexylaluminum, tripropylaluminum, tributylaluminum, trioctylaluminum, tridecylaluminum, It can be used after contacting an organoaluminum compound such as diisobutylaluminum hydride or an organoaluminum oxy compound containing an Al—O—Al bond.

(3) Preparation of catalyst for olefin polymerization The contact method of each component when obtaining the catalyst for olefin polymerization containing component (Ac), component (B), and component (C) is not particularly limited. Any method can be employed.

(I) The component (Ac) and the component (B) are contacted, and then the component (C) is contacted.
(II) The component (Ac) and the component (C) are contacted, and then the component (B) is contacted.
(III) The component (B) and the component (C) are contacted, and then the component (Ac) 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, generally aromatic hydrocarbons such as benzene, toluene, xylene and ethylbenzene (usually 6 to 12 carbon atoms), heptane, hexane, decane and dodecane. In the presence of a liquid inert hydrocarbon such as an aliphatic or alicyclic hydrocarbon (usually having 5 to 12 carbon atoms) such as cyclohexane, a method of bringing each component into contact with stirring or non-stirring is employed. 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.

  Further, when the component (Ac), the component (B) and the component (C) are contacted, as described above, a certain component is soluble or hardly soluble in an aromatic hydrocarbon solvent, and a certain component is insoluble. Any poorly 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 component (Ac), the component (B), and the component (C) is not particularly limited, but the following ranges are preferable.

When an organoaluminum oxy compound is used as the component (B), the atomic ratio (Al / M ^1c ) of the aluminum of the organoaluminum oxy compound to the transition metal (M ^1c ) in the component (Ac) that is a metallocene compound is usually The range of 1 to 100,000, preferably 5 to 1000, more preferably 50 to 200 is desirable. When a borane compound or a borate compound is used, the atomic ratio of boron to the transition metal (M ^1c ) in the metallocene compound (B / M ^1c ) is usually selected within 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 component (B), the same use as described above for the transition metal (M ^1c ) for each compound in the mixture It is desirable to select by percentage.

  Component (C) is used in an amount of 0.0001-5 mmol, preferably 0.001-0.5 mmol, more preferably 0.01-0. 1 g per millimole.

  The component (Ac), the component (B), and the component (C) are brought into contact with each other by any one of the contact methods (I) to (III), and then the solvent is removed for olefin polymerization. The catalyst can be obtained as a solid catalyst. The removal of the solvent is desirably performed under normal pressure or reduced pressure at 0 to 200 ° C., preferably 20 to 150 ° C. for 1 minute to 50 hours, preferably 10 minutes to 10 hours.

The olefin polymerization catalyst can also be obtained by the following method.
(IV) The component (Ac) and the component (C) are contacted to remove the solvent, and this is used as a solid catalyst component, which is contacted with an organoaluminum oxy compound, borane compound, borate compound or a mixture thereof under polymerization conditions. .
(V) The organoaluminum oxy compound, borane compound, borate compound or a mixture thereof and component (C) are contacted to remove the solvent, which is used as a solid catalyst component and contacted with component (Ac) under polymerization conditions. .
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.

  Moreover, a layered silicate can also be used as a component which serves as both the component (B) and the component (C), which are essential components in the method for producing an ethylene polymer of the present invention. 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.

In general, natural products are often non-ion-exchangeable (non-swellable). In that case, in order to have preferable ion-exchange (or swellable), ion exchange (or swellable) is provided. It is preferable to perform the process for providing. Among such treatments, particularly preferred are the following chemical treatments. Here, as the chemical treatment, any of a surface treatment for removing impurities adhering to the surface and a treatment that affects the crystal structure and chemical composition of the layered silicate can be used. Specifically, (a) acid treatment performed using hydrochloric acid, sulfuric acid, etc., (b) alkali treatment performed using NaOH, KOH, NH _3, etc., (c) selected from Groups 2 to 14 of the periodic table Salt treatment with a salt comprising at least one anion selected from the group consisting of a cation containing at least one atom and a halogen atom or an anion derived from an inorganic acid, (d) alcohol, hydrocarbon Examples thereof include organic compounds such as compounds, formamide and aniline. These processes may be performed independently or two or more processes may be combined.

  The layered silicate can be controlled in particle properties by pulverization, granulation, sizing, fractionation, etc. at any time before, during, or after all the steps. The method can be any purposeful. In particular, for granulation methods, for example, spray granulation method, rolling granulation method, compression granulation method, stirring granulation method, briquetting method, compacting method, extrusion granulation method, fluidized bed granulation Method, emulsion granulation method and submerged granulation method. Particularly preferable granulation methods are the spray granulation method, the rolling granulation method and the compression granulation method.

  Of course, the above-mentioned layered silicate can be used as it is, but these layered silicates are trimethylaluminum, triethylaluminum, triisobutylaluminum, tripropylaluminum, tributylaluminum, trihexylaluminum, trioctylaluminum, tridecylaluminum, It can be used in combination with an organoaluminum compound such as diisobutylaluminum hydride or an organoaluminum oxy compound containing an Al—O—Al bond.

In order to carry the component (Ac), which is an essential component of the method for producing an ethylene polymer of the present invention, on the layered silicate, the component (Ac) and the layered silicate are brought into contact with each other, or the component (Ac), An organoaluminum compound and a layered silicate may be brought into contact with each other.
The contact method of each component is not specifically limited, For example, the following methods are arbitrarily employable.
(VI) The component (Ac) and the organoaluminum compound are contacted, and then contacted with the layered silicate carrier.
(VII) The component (Ac) and the layered silicate carrier are contacted and then contacted with the organoaluminum compound.
(VIII) The organoaluminum compound and the layered silicate support are contacted and then contacted with the component (Ac).

  Of these contact methods, (VI) and (VIII) are preferred. In any contact method, usually in an inert atmosphere such as nitrogen or argon, generally aromatic hydrocarbons such as benzene, toluene, xylene and ethylbenzene (usually 6 to 12 carbon atoms), heptane, hexane, decane and dodecane. In the presence of a liquid inert hydrocarbon such as an aliphatic or alicyclic hydrocarbon (usually having 5 to 12 carbon atoms) such as cyclohexane, a method of bringing each component into contact with stirring or non-stirring is employed.

  Although the usage-amount of a component (Ac), an organoaluminum compound, and a layered silicate support | carrier is not specifically limited, The following ranges are preferable. The amount of the component (Ac) supported 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. In the case of using an organoaluminum compound, the amount of Al supported is preferably in the range of 0.01 to 100 mol, preferably 0.1 to 50 mol, more preferably 0.2 to 10 mol.

  For the method of supporting and removing the solvent, the same conditions as those for the inorganic carrier can be used. When a layered silicate is used as a component that serves as both the catalyst component (B) and the component (C), the resulting ethylene polymer has a narrow molecular weight distribution. Furthermore, the productivity of an ethylene polymer having a high polymerization activity and having a long chain branch is improved. The olefin polymerization catalyst thus obtained may be used after the prepolymerization of the monomer if necessary.

(4) Raw material ethylene polymer production method (polymerization method)
The above-mentioned catalyst for olefin polymerization can be suitably used for the production of the raw material ethylene polymer used in the present invention.

    In the present invention, the polymerization reaction can be carried out in the presence of the above-mentioned supported catalyst, preferably by slurry polymerization or gas phase polymerization. In the case of slurry polymerization, with substantially no oxygen, water, etc., aliphatic hydrocarbons such as isobutane, hexane and heptane, aromatic hydrocarbons such as benzene, toluene and xylene, and alicyclic rings such as cyclohexane and methylcyclohexane Ethylene or the like is polymerized in the presence or absence of an inert hydrocarbon solvent selected from group hydrocarbons and the like. Needless to say, liquid monomers such as liquid ethylene and liquid propylene can also be used as the solvent. 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, distributed, or circulated. 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 generally 5 minutes to 10 hours, preferably 1 hour to 8 hours, more preferably 2 hours to 7 hours.

  The molecular weight of the produced polymer can be adjusted to some extent by changing the polymerization conditions such as the polymerization temperature and the molar ratio of the catalyst, but the molecular weight can be adjusted more effectively by adding hydrogen to the polymerization reaction system. Can do. 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 present invention can also be applied to a multistage polymerization system having two or more stages having different polymerization conditions such as hydrogen concentration, monomer amount, polymerization pressure, and polymerization temperature without any trouble.

4). Production method of modified ethylene polymer The production method of the present invention satisfies the above-mentioned characteristics (1) to (5), and more preferably satisfies the above-mentioned characteristics (6) to (8). A modified ethylene-based polymer having a high melt tension of 10 mN or more by adding 0.00001 to 5 parts by weight of an organic peroxide to 100 parts by weight of the blend and melt-kneading the mixture. Is what you get.

(1) Organic peroxide Here, various known peroxides can be used as the organic peroxide. Examples of the type include diacyl peroxides, peroxydicarbonates, peroxyesters, peroxyketals, dialkyl peroxides, hydroperoxides and the like.
The 1 minute half-life decomposition temperature of the organic peroxide used in the present invention is preferably 150 to 200 ° C. Moreover, it is preferable that the temperature of melt kneading | mixing is 140-210 degreeC which is a range normally used as the kneading | mixing temperature of an ethylene-type polymer. When the half-life decomposition temperature is within the above range for this kneading temperature, the organic peroxide is sufficiently contained within the time for the melt-kneading process time (usually several seconds to several tens of minutes). It is because it can react.

  Specific examples include 1,1-di (t-butylperoxy) cyclohexane, 2,2-di (4,4-di- (t-butylperoxy) cyclohexyl) propane, and t-hexylperoxyisopropyl. T-butyl peroxymaleic acid, t-butyl peroxy-3,5,5-trimethylhexanoate, t-butyl peroxylaurate, t-butyl peroxyisopropyl monocarbonate, t-butyl peroxy-2 -Ethylhexyl monocarbonate, t-hexyl peroxybenzoate, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, t-butyl peroxyacetate, 2,2-di (t-butylperoxy) butane, t-butyl peroxybenzoate, n-butyl 4,4-di (t-butylperoxy) ba Rate, di (2-t-butylperoxyisopropyl) benzene, dicumyl peroxide, di-t-hexyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, t-butyl Cumyl peroxide, di-t-butyl peroxide, p-menthane hydroperoxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3, or a plurality selected from these A mixture of peroxides may also be used.

  Of these, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane and t-butylperoxy-2-ethylhexyl monocarbonate are particularly preferably used.

  The addition amount of the organic peroxide is 0.00001 to 5 parts by weight, preferably 0.00005 to 3 parts by weight, more preferably 0.0001 to 1 part by weight with respect to 100 parts by weight of the raw ethylene polymer. The most preferred amount is 0.005 to 0.5 parts by weight. If the amount of the organic peroxide is less than this amount, the modification effect is not sufficient, and if it exceeds, the hue, long-term durability and odor of the modified ethylene polymer are inferior.

(2) Production Method of Modified Ethylene Polymer A long chain branched structure can be further introduced into the raw ethylene polymer by adding an organic peroxide and performing melt kneading. Here, as a melt-kneading technique, various known melt-kneading techniques such as a single-screw extruder, a twin-screw extruder, a Banbury mixer, a roll mixer, a Brabender plastograph, and a kneader can be used without particular limitation. The temperature of the melt kneading is 140 to 210 ° C., preferably 150 to 200 ° C. However, if the kneading machine is capable of setting a plurality of temperatures, such as a single screw extruder or a twin screw extruder, The temperature of the zone where the peroxide is supposed to react may be set in consideration of the residence time of the resin and the half-life temperature of the organic peroxide used.
The melt kneading time is usually 1 to 25 minutes, preferably 5 to 20 minutes, and the rotational speed during kneading is preferably 40 to 120 RPM. Furthermore, in order to homogenize the material before melt kneading, it is preferable to knead at 100 to 140 ° C., 1 to 10 minutes, and at a rotational speed of about 2 to 100 RPM.

  During the melt-kneading, additives other than the organic peroxide can be added within the range not exceeding the gist of the present invention. For example, various α, ω-dienes, crosslinking aids such as divinylbenzene and triallyl isocyanurate, nucleating agents, phenolic antioxidants, phosphorus antioxidants, sulfur antioxidants, neutralizers, light stability Agents, ultraviolet absorbers, lubricants, antistatic agents, metal deactivators, fillers, antibacterial agents, antifungal agents, fluorescent whitening agents, colorants, plasticizers, foaming agents and the like. Generally, the compounding amount of these additives is 0.00001 to 3 parts by weight, preferably 0.0001 to 1 part by weight with respect to 100 parts by weight of the resin.

  Moreover, it is also possible to add other resin in the range which does not exceed the main point of this invention. For example, various polyethylenes (other than the raw ethylene polymer of the present invention), various polypropylenes, ethylene elastomers, other olefin elastomers, various poly α-olefin polymers having 4 or more carbon atoms, ethylene-diene monomers Copolymers, acid-modified polyolefins, polydiene (co) polymers, styrene elastomers, acrylic acid copolymers, methacrylic acid copolymers, ABS resins, petroleum resins, vinyl chloride resins, polycarbonates, various ionomers It is done. These addition amounts are generally 1 part by weight to 50 parts by weight with respect to 100 parts by weight of the starting ethylene polymer.

(3) Properties of modified ethylene polymer [melting tension (MT)]
The modified polyethylene obtained by the production method of the present invention has a melt tension (MT) of 10 mN or more. This is because when the melt tension is in the above range, molding stability such as difficulty in drawing down and uniform thickness distribution can be expected.
For example, in FIG. 5, as an example of an embodiment of the present invention, an unmodified raw material ethylene polymer (Comparative Example 5 and Comparative Example 6) having a melt tension of less than 10 mN is melted by modification with an organic peroxide. The modified polyethylene (Examples 1-4) improved to 10 mN or more is shown. Thus, according to the manufacturing method of this invention, even if it is an ethylene-type polymer whose melt tension is less than 10 mN, melt tension can be 10 mN or more.
The melt tension can be measured by measuring the stress when the melted polyethylene is stretched at a constant speed.
In general, the value of the melt tension increases as the MFR decreases, but the production method of the present invention can be achieved by using a starting ethylene polymer that satisfies the characteristics (1) to (5). Compared to the ethylene polymer produced by the prior art, the melt tension is set to be higher than the MFR.
For example, FIGS. 4-1 to 3 show that a predetermined amount of organic polymer is obtained using the raw material ethylene polymer (Examples 1 to 4) and other commercially available ethylene polymers (Comparative Examples 1 to 4) in the present invention. The melt tension (MT) with respect to MFR in the case of being modified with an oxide is shown. In any MFR range, the modified polyethylene obtained by the production method of the present invention has a higher melt tension (MT). ) Is clearly shown.
As the melt tension of the modified polyethylene obtained by the production method of the present invention, for example, when the MFR is 1.0 to 2.0 g / 10 min, it is preferably 50 mN or more, more preferably 60 mN or more, further preferably 70 mN. For example, when MFR is more than 2.0 g / 10 min to 5.0 g / 10 min, it is preferably 20 mN or more, more preferably 30 mN or more, and further preferably 40 mN or more. For example, when MFR is more than 5.0 g / 10 min to 10.0 g / 10 min, it is preferably 10 mN or more, more preferably 12 mN or more, and further preferably 14 mN or more.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to these examples. The evaluation methods used in the examples are as follows, and the following catalyst synthesis step and polymerization step are all performed under a purified nitrogen atmosphere, and the solvent used was dehydrated and purified with molecular sieve 4A. Was used.

Evaluation Method (I) Various Evaluation (Measurement) Methods (i) MFR:
Based on JIS K7210, it measured by 190 degreeC and the 2.16kg load.
(Ii) Density:
The density was measured by a density gradient tube method after the strand obtained at the time of MFR measurement was heat-treated at 100 ° C. for 1 hour and further left at room temperature for 1 hour in accordance with JIS K7112.
(Iii) Mw / Mn
It was determined by the method described in the above specification by GPC measurement.
(Iv) The branching index g ′ and the W value were determined by the method described in the above specification using a GPC measuring apparatus in combination with a differential refractometer, a viscosity detector, and a light scattering detector.
(V) Strain hardening degree of elongational viscosity (λmax)
Using a rheometer, measurement was performed by the method described in the present specification. Prior to the preparation of the test piece, the polymer was dissolved and reprecipitated according to the following procedure. 300 ml of xylene was introduced into a 500 ml two-necked flask equipped with a cooling tube, and nitrogen bubbling was performed at room temperature for 30 minutes. 6.0 grams of polymer and 1.0 gram of 2,6-di-t-butylhydroxytoluene (BTH) were introduced. The mixture was stirred at 125 ° C. for 30 minutes under a nitrogen atmosphere to completely dissolve the polymer in xylene. The xylene solution in which the polymer was dissolved was poured into 2.5 L of ethanol to precipitate the polymer. The polymer recovered by filtration was dried with a vacuum dryer at 80 ° C.
(Vi) W- ₁₅ value It was determined by the method described in the specification by TREF measurement using orthodichlorobenzene as a solvent.
(Vii) Melt tension (MT)
MT (load) applied when a take-up speed of 3 m / min is taken at a constant value measured under the following conditions using a Capillograph type 1C (barrel inner diameter 9.55 mm) manufactured by Toyo Seiki Seisakusho.
Temperature: 190 ° C
Orifice: (L / D = 8mm / 2.1mm)
Piston speed: 15 mm / min Distance from die outlet to load measurement position: 40 cm

[Preparation of raw ethylene polymer]
[Adjustment of metallocene catalyst]
[Synthesis Example 1]
Add dimethyl (4-t-butyl-cyclopentadienyl) (4- (2- (5-methyl) -furyl) -indenyl) silane (4.00 g, 10.7 mmol) and 40 ml of diethyl ether to a 200 ml flask. Then, an n-butyllithium / hexane solution (2.5 M, 9.4 ml, 23.5 mmol) was added at −78 ° C., and the mixture was stirred at room temperature for 2 hours and further at 50 ° C. for 1 hour. Volatile components were distilled off under reduced pressure, followed by addition of 100 ml of dichloromethane, and zirconium tetrachloride (2.50 g, 10.7 mmol) was added at −78 ° C., followed by stirring at room temperature for 12 hours. The reaction mixture was filtered, and the obtained filtrate was concentrated to obtain a crude complex as an isomer mixture. The crude complex was washed three times with 20 ml of diethyl ether to give 1.2 g of dimethylsilylene (4- (2- (5-methyl) -furyl) -indenyl) (4-tert-butyl-cyclopentadienyl) zirconium dichloride ( Yield 21%).
Next, under a nitrogen atmosphere, 30 grams of silica baked at 600 ° C. for 5 hours was placed in a 500 ml three-necked flask and dried under reduced pressure with a vacuum pump for 1 hour while heating in an oil bath at 150 ° C. Dimethylsilylene (4- (2- (5-methyl) -furyl) -indenyl) (4-t-butyl-cyclopentadienyl) zirconium dichloride synthesized above in a separately prepared 200 ml two-necked flask under a nitrogen atmosphere After adding 338 milligrams and dissolving in 67.7 ml of dehydrated toluene, 43.4 ml of 20% methylaluminoxane / toluene solution manufactured by Albemarle was further added at room temperature and stirred for 30 minutes. While heating and stirring the 500 ml three-necked flask containing the vacuum-dried silica in an oil bath at 40 ° C., the total amount of the toluene solution of the reaction product of the complex and methylaluminoxane was added. After stirring at 40 ° C. for 1 hour, the toluene solvent was distilled off under reduced pressure while heating to 40 ° C. to obtain a solid catalyst.

[Synthesis Example 2]
To a 300 ml flask, 1.20 g (3.00 mmol) of (4- (4-trimethylsilylphenyl) indenyl) (cyclopentadienyl) dimethylsilane and 20 ml of diethyl ether were added and cooled to -70 ° C. To this was added dropwise 2.60 ml (6.60 mmol) of a 2.5 mol / L n-butyllithium-n-hexane solution. After dropping, the temperature was returned to room temperature and stirred for 2 hours. The solvent of the reaction solution was distilled off under reduced pressure, 30 ml of dichloromethane was added, and the solution was cooled to −70 ° C. in a dry ice-methanol bath. Thereto, 0.770 g (3.30 mmol) of zirconium tetrachloride was added. Thereafter, the mixture was stirred overnight while gradually returning to room temperature. A yellow powder was obtained by distilling off the solvent under reduced pressure from the filtrate obtained by filtering the reaction solution. This powder was recrystallized with 10 ml of toluene to obtain 0.500 g (yield 31%) of dimethylsilylene (4- (4-trimethylsilylphenyl) indenyl) (cyclopentadienyl) zirconium dichloride as yellow crystals.
Next, under a nitrogen atmosphere, 30 grams of silica baked at 600 ° C. for 5 hours was placed in a 500 ml three-necked flask and dried under reduced pressure with a vacuum pump for 1 hour while heating in an oil bath at 150 ° C. In a 200 ml two-necked flask prepared separately, 820 milligrams of dimethylsilylene (4- (4-trimethylsilylphenyl) indenyl) (cyclopentadienyl) zirconium dichloride synthesized above was placed in a nitrogen atmosphere and dissolved in 67.7 ml of dehydrated toluene. Then, 43.4 ml of a 20% methylaluminoxane / toluene solution manufactured by Albemarle was added at room temperature and stirred for 30 minutes. While heating and stirring the 500 ml three-necked flask containing the vacuum-dried silica in an oil bath at 40 ° C., the total amount of the toluene solution of the reaction product of the complex and methylaluminoxane was added. After stirring at 40 ° C. for 1 hour, the toluene solvent was distilled off under reduced pressure while heating to 40 ° C. to obtain a solid catalyst.

[Polymerization of raw ethylene polymer]
[Polymerization Example 1]
Ethylene / 1-hexene gas phase continuous copolymerization was carried out using the solid catalyst obtained in Synthesis Example 1. That is, a gas phase continuous polymerization apparatus (internal volume) prepared at a temperature of 75 ° C., a hexene / ethylene molar ratio of 0.009, a hydrogen / ethylene molar ratio of 6.2 × 10 ⁻⁴ , a nitrogen concentration of 20 mol%, and a total pressure of 0.8 MPa. 100 L, fluidized bed diameter 10 cm, fluidized bed seed polymer (dispersant) 1.8 kg), while the solid catalyst is intermittently supplied at a rate of 0.51 g / hour, polymerization is performed with a constant gas composition and temperature. went. Further, in order to maintain cleanliness in the system, 0.03 mol / L of hexane diluted solution of triethylaluminum (TEA) was supplied to the gas circulation line at 12 ml / hr. As a result, the average production rate of the produced polyethylene was 373 g / hour. The content of 1-hexene in the ethylene polymer obtained after producing a cumulative amount of polyethylene of 5 kg or more was 6.2% by weight, and the MFR and density were 9.5 g / 10 min and 0.930 g / cm ³ , respectively. there were.

[Polymerization Example 2]
Using the solid catalyst obtained in Synthesis Example 2, ethylene / 1-hexene gas phase continuous copolymerization was carried out in the same manner as in Polymerization Example 1. That is, a gas phase continuous polymerization apparatus (internal volume) prepared at a temperature of 75 ° C., a hexene / ethylene molar ratio of 0.003, a hydrogen / ethylene molar ratio of 5.2 × 10 −3, a nitrogen concentration of 20 mol%, and a total pressure of 0.8 MPa. 100 L, fluidized bed diameter 10 cm, fluidized bed seed polymer (dispersant) 1.8 kg), while continuously supplying the solid catalyst at a rate of 0.92 g / hour, polymerization was performed with a constant gas composition and temperature. went. Further, in order to maintain cleanliness in the system, 0.03 mol / L of hexane diluted solution of triethylaluminum (TEA) was supplied to the gas circulation line at 12 ml / hr. As a result, the average production rate of the produced polyethylene was 285 g / hour. The content of 1-hexene in the ethylene polymer obtained after producing a cumulative amount of polyethylene of 4 kg or more was 5.4% by weight, and the MFR and density were 7.1 g / 10 min and 0.93 g / cm ³ , respectively. there were.
Various evaluation results of the raw material ethylene polymer obtained as a result of the polymerization are shown in Table 1.

The following samples were used as a comparative raw material ethylene polymer. All of the evaluation results are shown in Table 1.
KJ640T (manufactured by Nippon Polyethylene Co., Ltd.): A commercially available ethylene / α-olefin copolymer into which short chain branching by comonomer (1-hexene, propylene) is introduced.
MFR = 30 g / 10 min, density = 0.88 g / cm ³
KS571 (manufactured by Nippon Polyethylene Co., Ltd.): A commercially available ethylene / α-olefin copolymer into which short chain branching by a comonomer (1-hexene) has been introduced. MFR = 12.0 g / 10 min, density = 0.91 g / cm ³
KF370 (manufactured by Nippon Polyethylene Co., Ltd.): A commercially available ethylene / α-olefin copolymer into which short chain branching by a comonomer (1-hexene) has been introduced. MFR = 3.5 g / 10 min, density = 0.91 g / cm ³
In addition, as shown in Table 1, the g ′ values of the samples used in these comparative examples are 0.80 to 0.86, which is smaller than 1. When the g ′ value is also affected to some extent by the amount of comonomer, it is described in the document Polymer, 46, (2005), p5165-5182, and these samples do not exhibit strain hardening of elongational viscosity. The g ′ value is considered to be smaller than 1 due to the amount of comonomer.

[Example 1]
Perhexa 25B (Compound name: 2,5-Dicumyl-2,5-bis (t-butylperoxy) hexane) manufactured by Nippon Oil &Fats; 100 minutes by weight of the starting ethylene polymer obtained in Polymerization Example 1; 0.02 part by weight of an initial temperature of 179.8 ° C.) is added. 10 g of this was put into a melt kneading machine Xplore manufactured by DSM, homogenized by kneading for 5 minutes under the conditions of a screw rotation speed of 50 RPM and a barrel temperature of 130 ° C., and then the barrel temperature was raised to 190 ° C. After kneading at 100 RPM for 15 minutes, 0.02 g of Irg1010 was added as an antioxidant, and further, the sample was recovered by kneading at 190 ° C. and 100 RPM for 2 minutes at Xplore. This is a modified ethylene polymer. Table 2 shows the measurement results of MFR and MT of the modified ethylene polymer.

[Example 2]
It carried out similarly to Example 1 except having changed the quantity of the organic peroxide to add into 0.05 weight part. Table 2 shows the measurement results of MFR and MT of the modified ethylene polymer.

[Example 3]
It carried out similarly to Example 1 except having changed the quantity of the organic peroxide to add into 0.10 weight part. Table 2 shows the measurement results of MFR and MT of the modified ethylene polymer.

[Example 4]
The same procedure as in Example 2 was performed except that the raw material ethylene polymer obtained in Polymerization Example 2 was used as a raw material. Table 2 shows the measurement results of MFR and MT of the modified ethylene polymer.

[Comparative Example 1]
It carried out like Example 2 except having used KJ640T as a raw material ethylene polymer. Table 2 shows the measurement results of MFR and MT of the modified ethylene polymer.

[Comparative Example 2]
It carried out like Example 3 except having used KJ640T as a raw material ethylene polymer. Table 2 shows the measurement results of MFR and MT of the modified ethylene polymer.

[Comparative Example 3]
The same operation as in Example 2 was conducted except that KS571 was used as a raw material ethylene polymer. Table 2 shows the measurement results of MFR and MT of the modified ethylene polymer.

[Comparative Example 4]
The same operation as in Example 1 was performed except that KF370 was used as a raw material ethylene polymer and the number of revolutions at 190 ° C. was 50 rpm. Table 2 shows the measurement results of MFR and MT of the modified ethylene polymer.

[Comparative Example 5]
Perhexa 25B (compound name: 2,5-dicumyl-2,5-bis (t-butylperoxy) hexane; 1 minute half-life temperature 179.8 ° C.) was added except that Nippon Oil & Fats Perhexa 25B was used. Samples were obtained as well. The MFR of the sample after kneading was 16.3, which was higher than that of the raw material powder.

[Comparative Example 6]
Perhexa 25B (compound name: 2,5-dicumyl-2,5-bis (t-butylperoxy) hexane; 1 minute half-life temperature 179.8 ° C.) was added except that Nippon Oil & Fats Perhexa 25B was used. Samples were obtained as well. The MFR of the sample after kneading was 7.8.

[Evaluation]
FIG. 4A to FIG. 4C show plots of MFR and MT of Examples and Comparative Examples 1 to 4. As is apparent from the figure, in Examples 1 to 4 in which raw material ethylene polymers satisfying the characteristics (1) to (5) are used, MT is clearly higher than MFR in comparison with Comparative Examples. Thus, higher MT compared with the prior art means that the amount of organic peroxide added can be reduced in order to obtain a specific MT. Not only is it possible to reduce various problems such as hue, long-term durability and odor caused by the addition of substances, but it is also useful from the viewpoint of safety and economy.
FIG. 5 shows plots of MFR and MT of Examples 1 to 4 and Comparative Examples 5 and 6. Comparative Examples 5 and 6 are unmodified polyethylene satisfying the characteristics (1) to (5), and MT is already higher than MFR compared to Comparative Examples 1 to 4, but MT can be further improved by modifying it. Is clearly improved to 10 mN or more.

The method for producing a modified ethylene polymer of the present invention has a high melt tension (MT) relative to the fluidity compared to the prior art, and an ethylene polymer having the characteristics of improving various molding processes. To manufacture. The modified ethylene polymer produced according to the present invention can increase the fluidity while maintaining a high melt tension, so the load on the extruder during the molding process is reduced, and the power consumption during the molding process is reduced. Can be suppressed. This characteristic is very useful industrially in fields requiring high melt tension or elongational viscosity characteristics such as film molding, blow molding and foam molding.
In addition, when an ethylene polymer is modified with an organic peroxide to obtain a specific melt tension (MT), a high melt tension (MT) can be achieved by using a small amount of the organic peroxide. It is considered that the deterioration of the hue and the odor can be suppressed because the residue of the organic peroxide in the modified polyethylene can be suppressed.

Claims (6)

By blending 0.00001 to 5 parts by weight of an organic peroxide with respect to 100 parts by weight of a raw material ethylene polymer that satisfies the following characteristics (1) to (5), and melt-kneading, the melt tension is 10 mN. A method for producing a modified ethylene polymer, comprising the step of obtaining the modified ethylene polymer.
(1) MFR = 0.1-200 g / 10 min (2) Density = 0.88-0.97 g / cm ³
(3) Mw / Mn = 2-10
(4) The minimum value of the branching index g ′ measured by a GPC measuring apparatus combining a differential refractometer, a viscosity detector, and a light scattering detector is between 0.25 and 0 in a molecular weight of 100,000 to 1,000,000. .75.
(5) A polymer produced by a polymerization reaction of ethylene using a catalyst containing a transition metal metallocene compound . The method for producing a modified ethylene polymer according to claim 1, wherein the raw material ethylene polymer satisfies the following characteristic (6).
(6) Logarithmic plot of elongational viscosity η (t) (unit: Pa · second) and elongation time t (unit: second) measured at a temperature of 170 ° C. and an elongation strain rate of 2.0 (unit: 1 / second) , When the inflection point of the extension viscosity due to strain hardening is observed, the maximum extension viscosity after strain hardening is ηMax (t1), and the approximate straight line of the extension viscosity before hardening is ηLinear (t1). ) / ΗLinear (t1), the strain hardening degree λmax (2.0) is 1.2-30. In addition, t1 is the time (unit: second) when the maximum extensional viscosity was observed.   The method for producing a modified ethylene polymer according to claim 1 or 2, wherein the one-minute half-life decomposition temperature of the organic peroxide is 150 to 200 ° C. The method for producing a modified ethylene polymer according to any one of claims 1 to 3, wherein the raw material ethylene polymer is produced by a polymerization catalyst containing the following essential component (Ac). .
Component (Ac): Metallocene compound represented by the following general formula (1c)
[In formula (1c), M ^1c represents a transition metal of Ti, Zr or Hf. X ^1c and X ^2c are each independently a hydrogen atom, halogen, a hydrocarbon group having 1 to 20 carbon atoms, a hydrocarbon group having 1 to 20 carbon atoms including oxygen or nitrogen, or a hydrocarbon having 1 to 20 carbon atoms. A group-substituted amino group or an alkoxy group having 1 to 20 carbon atoms is shown. Q ^1c and Q ^2c represent a carbon atom, a silicon atom, or a germanium atom. zR ^1c each independently represents a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, and two or four R ^1c form a ring together with the bonded Q ^1c and Q ^2c. May be. ^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, halogen, 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 oxygen or a C1-C20 hydrocarbon group-substituted silyl group. R ^3c represents a substituted aryl group represented by the following general formula (1-ac). ]
[In formula (1-ac), Y1c represents an atom of Group 14, 15 or 16 of the periodic table. R ^5c , R ^6c , R ^7c , R ^8c and R ^9c each independently represents a hydrogen atom, a chlorine atom, a bromine atom, a hydrocarbon group having 1 to 20 carbon atoms, a C 1 to 20 carbon atom containing oxygen or nitrogen. Hydrocarbon group substituted amino group having 1 to 20 carbon atoms, alkoxy group having 1 to 20 carbon atoms, silicon-containing hydrocarbon group having 1 to 18 carbon atoms including 1 to 6 silicon atoms, 1 to carbon atoms 20 halogen-containing hydrocarbon group or a C1-C20 hydrocarbon group-substituted silyl group, wherein R ^5c , R ^6c , R ^7c , R ^8c and R ^9c are bonded to each other at adjacent R's. A ring may be formed together with the atom. n ^c is 0 or 1, if ^{n c} is ^0, there is no substituent ^{R 5c} to ^{Y 1c.} p ^c is 0 or 1, if ^{p c} is ^0, the carbon atom ^{to which R 8c} and ^{R 8c} is attached is ^absent, the carbon atom to which carbon atoms and ^{R 9c which R 7c} is attached is bound is a direct bond doing. 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 method for producing a modified ethylene polymer according to claim 4, wherein the polymerization catalyst further contains the following essential components (B) and (C).
Component (B): Compound that reacts with component (Ac) to form a cationic metallocene compound Component (C): Fine particle carrier   The method for producing a modified ethylene polymer according to any one of claims 1 to 5, wherein the melt kneading is performed in a temperature range of 140 to 210 ° C.