JP5767202B2 - Ethylene polymer, stretched molded body, microporous membrane, and battery separator - Google Patents

Description

  The present invention relates to an ethylene polymer and a stretch-molded product including the same, a microporous membrane, and a battery separator.

  Ethylene polymers are used in various applications such as sheets, films, microporous membranes, molded bodies and the like. In these applications, excellent puncture strength is required. The microporous membrane containing an ethylene polymer functions as a separator that separates the positive and negative electrodes and allows only ions to pass through in battery applications, and shuts down to prevent the risk of the battery reaction running away due to high temperature inside the battery. It is used as a member having both functions. In particular, a microporous film containing an ethylene polymer is used as a separator for a lithium ion battery or a lead storage battery (see, for example, Patent Document 1). Also in these uses, it is calculated | required that it is excellent in puncture strength, and the high-density polyethylene with a high crystallinity degree is mainly used (for example, refer patent document 2).

  In general, a process for stretching a microporous membrane or the like includes a stretching process. In such a case, except for a specific application such as a shrink film, in order to suppress the thermal shrinkage after stretching and the thermal shrinkage under the use environment, an annealing is usually performed to relax the molecular orientation (hereinafter, (Also referred to as “heat setting”). In the heat setting step, molecular orientation is relaxed by molecular movement of a component that is likely to undergo molecular movement even at a low temperature (hereinafter also referred to as “amorphous component”). However, high-density polyethylene having a high degree of crystallinity has a problem that the molecular orientation may not be sufficiently relaxed due to a small amount of amorphous components, and the thickness of the microporous film is not stable due to heat shrinkage.

  As a technique for solving the above problem, a method of blending a relatively low molecular weight ethylene polymer and an ultrahigh molecular weight ethylene polymer (for example, see Patent Document 3) is known. Patent Document 3 is a technique of blending an ethylene polymer having a viscosity average molecular weight (Mv) of 300,000 or less and a high molecular weight ethylene polymer having a viscosity average molecular weight (Mv) of 1,000,000 or more. In general, it is known that the crystalline component increases as the molecular weight increases, and it is considered that the ultrahigh molecular weight ethylene polymer contributes to the strength and the low molecular weight ethylene polymer contributes to the heat shrinkability. .

JP 60-23594 A WO2011 / 118735 JP-A-2-21559

  However, since the ultrahigh molecular weight ethylene polymer has a problem that it is inferior in melt fluidity and solubility in a solvent, an ethylene polymer that is excellent in strength and easy to handle is desired. On the other hand, ethylene polymers with low molecular weight are inferior in heat resistance and have problems such as not being able to sufficiently raise the annealing temperature in heat setting, so that they have moderate molecular mobility at low temperatures and excellent dimensional accuracy. A polymer is desired.

  The present invention has been made in view of the above problems, and an ethylene polymer having excellent strength and dimensional accuracy, and a stretch-molded product, a microporous membrane, and a battery including the same, excellent in strength and dimensional accuracy. An object of the present invention is to provide a separator.

  As a result of diligent research to solve the above problems, the present inventors have obtained a predetermined viscosity average molecular weight, a predetermined molecular weight distribution, and a predetermined elution amount of 103 ° C. measured by a cross fractionation chromatograph (CFC). It discovered that the ethylene polymer which it has can solve said subject, and came to this invention.

  That is, the present invention is as follows.
[1]
  The viscosity average molecular weight (Mv) is 200,000 or more and 500,000 or less,
  The molecular weight distribution (Mw / Mn) is 3.0 or more and 10.0 or less,
  There are two or more elution peaks measured by cross-fractionation chromatography (hereinafter referred to as “CFC”) measured using o-dichlorobenzene as a solvent under the following conditions (1) to (3):
  The elution amount at 103 ° C. measured by CFC is 10% by mass or more and 20% by mass or less of the total elution amount,
  Integral elution amount measured by CFC from 96 ° C to less than 100 ° C is 55% by mass or less of the total elution amount
And
  The integrated elution amount measured by CFC of 100 ° C or more and less than 104 ° C is 35% by mass or less of the total elution amount.
Above,
  Ethylene polymer.
    (1) Hold an o-dichlorobenzene solution of an ethylene polymer at 140 ° C. for 120 minutes.
    (2) The temperature of the ethylene polymer o-dichlorobenzene solution is lowered to 40 ° C. at 0.5 ° C./min, and then held for 20 minutes.
    (3) The temperature of the column is increased at a rate of 20 ° C./min by the temperature program shown in the following (a) to (e). Hold that temperature for 21 minutes at each temperature reached.
        (A) The temperature is increased from 40 ° C. to 60 ° C. at intervals of 10 ° C.
        (B) The temperature is raised from 60 ° C. to 75 ° C. at intervals of 5 ° C.
        (C) The temperature is raised from 75 ° C. to 90 ° C. at intervals of 3 ° C.
        (D) The temperature is increased from 90 ° C. to 110 ° C. at 1 ° C. intervals.
        (E) The temperature is raised from 110 ° C. to 120 ° C. at intervals of 5 ° C.
[2]
  The ethylene polymer according to [1], which is a homopolymer.
[3]
  The ethylene polymer according to [1] or [2], which is linear.
[4]
  The ethylene polymer according to any one of [1] to [3], wherein a melting point measured by a differential scanning calorimeter (DSC) is 133 ° C. or higher and 138 ° C. or lower.
[5]
  The ethylene polymer according to any one of [1] to [4] above, wherein an integrated elution amount of 40 ° C. or more and less than 96 ° C. measured by CFC is 10% by mass or less of the total elution amount.
[6]
  The ethylene polymer according to any one of [1] to [5], wherein the residual catalyst ash content is 50 ppm or less.
[7]
  A component having a molecular weight of 1,000,000 or more in terms of polystyrene is 10% by mass or less.
The ethylene polymer according to any one of [1] to [6] above.
[8]
  A stretch-molded product comprising the ethylene polymer according to any one of [1] to [7] above.
[9]
  A microporous membrane comprising the ethylene polymer according to any one of [1] to [7] above.
[10]
  A battery separator comprising the ethylene polymer according to any one of [1] to [7].

  ADVANTAGE OF THE INVENTION According to this invention, the extending | stretching molded object, the microporous film, and the battery separator which were excellent in the intensity | strength and dimensional accuracy containing this can be implement | achieved.

It is a temperature profile in cross fraction chromatography (CFC) measurement. It is an elution temperature-elution amount curve obtained by cross fraction chromatography (CFC) measurement.

  Hereinafter, a mode for carrying out the present invention (hereinafter also referred to as “the present embodiment”) will be described in detail. In addition, this invention is not limited to this embodiment, It can implement in various deformation | transformation within the range of the summary.

[Ethylene polymer]
The ethylene polymer of this embodiment has a viscosity average molecular weight (Mv) of 200,000 or more and 500,000 or less, a molecular weight distribution (Mw / Mn) of 3.0 or more and 10.0 or less, and cross fractionation chromatography. The amount of elution at 103 ° C. measured in (hereinafter also referred to as “CFC”) is 10% by mass or more and 20% by mass or less of the total elution amount. The above requirements will be described below.

[Viscosity average molecular weight (Mv)]
The viscosity average molecular weight (Mv) of the ethylene polymer of this embodiment is 200,000 or more and 500,000 or less, preferably 210,000 or more and 480,000 or less, more preferably 220,000 or more and 460,000. It is as follows. The Mv of the ethylene polymer can be adjusted by using a catalyst described later and appropriately adjusting the polymerization conditions and the like. Specifically, the viscosity average molecular weight (Mv) can be adjusted by allowing hydrogen to be present in the polymerization system or changing the polymerization temperature. By adding hydrogen as a chain transfer agent in the polymerization system, the molecular weight can be controlled within an appropriate range.

  When the viscosity average molecular weight (Mv) is 200,000 or more, the amount of the crystalline component measured by CFC increases, and a desired strength can be expressed. In addition, the stretched molded product, the microporous membrane, and the battery separator including the ethylene polymer of the present embodiment have excellent strength. On the other hand, when the viscosity average molecular weight (Mv) is 500,000 or less, melt fluidity, dissolution in a solvent, stretching, and the like are facilitated, and processability is improved.

For the viscosity average molecular weight (Mv) of the ethylene polymer of this embodiment, solutions prepared by dissolving ethylene polymers at different concentrations in decalin are prepared, and the solution viscosity at 135 ° C. of the solution is measured. The reduced viscosity calculated from the solution viscosity thus measured is extrapolated to a concentration of 0, the intrinsic viscosity is determined, and the calculated intrinsic viscosity [η] (dL / g) can be calculated by the following formula A. it can. More specifically, it can be measured by the method described in the examples.
Mv = (5.34 × 10 ⁴ ) × [η] ^1.49 Formula A

[Molecular weight distribution (Mw / Mn)]
The molecular weight distribution (Mw / Mn) of the ethylene polymer of this embodiment is from 3.0 to 10.0, preferably from 3.2 to 9.8, more preferably from 3.4 to 9. 5 or less. The molecular weight distribution of the ethylene polymer can be made small (10.0 or less) by using the catalyst of this embodiment or keeping the conditions (hydrogen concentration, temperature, ethylene pressure, etc.) in the polymerization system constant. . Therefore, it is preferable to perform polymerization in a continuous manner. On the other hand, as a method for increasing the molecular weight distribution of the ethylene polymer, the polymerization conditions are changed by batch polymerization (for example, the concentration of hydrogen as a chain transfer agent is changed during polymerization), or batch polymerization. And a method of intermittently introducing the catalyst.

  If the molecular weight distribution (Mw / Mn) is 3.0 or more, the ethylene polymer of the present embodiment has a more excellent moldability, and as a result, the stretch-molded product, the microporous material containing the ethylene polymer. The membrane and the battery separator have excellent dimensional accuracy and strength. On the other hand, if the molecular weight distribution (Mw / Mn) is 10.0 or less, the molecular chain length becomes uniform, which increases the amount of crystalline components measured by CFC, which will be described later. Can have.

  The number average molecular weight (Mn), the weight average molecular weight (Mw), and the molecular weight distribution (Mw / Mn) of the ethylene polymer of the present embodiment are obtained by gel permeation chromatography (hereinafter referred to as “orthodichlorobenzene solution”) in which the ethylene polymer is dissolved. , Also referred to as “GPC”), and can be determined based on a calibration curve prepared using commercially available monodisperse polystyrene. More specifically, it can be measured by the method described in the examples.

[103 ° C elution amount measured by cross-fractionation chromatography (CFC)]
The elution amount at 103 ° C. measured by CFC of the ethylene polymer of this embodiment is 10% by mass or more and 20% by mass or less, preferably 10.5% by mass or more and 19.5% by mass or less of the total elution amount. More preferably, it is 11 mass% or more and 19 mass% or less. When the elution amount at 103 ° C. is 10% by mass or more and 20% by mass or less of the total elution amount, high strength can be expressed without excessively increasing the crystallinity of the ethylene polymer. Therefore, molecular relaxation is sufficiently performed in the heat setting step, and a microporous film having excellent dimensional accuracy can be obtained.

  Here, “cross-fractionation chromatography (CFC)” is a device that combines a temperature-rise elution fractionation section (hereinafter also referred to as “TREF section”) that performs crystalline fractionation and a GPC section that performs molecular weight fractionation. Thus, by directly connecting the TREF part and the GPC part, the apparatus can analyze the mutual relationship between the composition distribution and the molecular weight distribution. Note that the measurement at the TREF unit may be referred to as the measurement at the CFC.

  The measurement by the TREF part is performed as follows based on the principle described in “Journal of Applied Polymer Science, Vol 26, 4217-4231 (1981)”. The ethylene polymer to be measured is completely dissolved in orthodichlorobenzene. Thereafter, it is cooled at a constant temperature to form a thin polymer layer on the surface of the inert carrier. At this time, a component having high crystallinity is first crystallized, and subsequently, a component having low crystallinity is crystallized as the temperature decreases. Next, when the temperature is raised stepwise, the components having low crystallinity are eluted in order from the components having high crystallinity, and the concentration of the eluted component at a predetermined temperature can be detected. The “elution amount at 103 ° C.” in the present embodiment indicates the amount of the ethylene polymer eluted at 103 ° C. when the temperature is increased.

  The elution amount and elution integration amount at each temperature of the ethylene polymer can be determined by measuring an elution temperature-elution amount curve as follows using a TREF section. FIG. 1 shows the temperature profile of the column. Specifically, first, the column containing the filler is heated to 140 ° C., and a sample solution (for example, concentration: 20 mg / 20 mL) in which an ethylene polymer is dissolved in orthodichlorobenzene is introduced and held for 120 minutes. .

  Next, after the temperature is lowered to 40 ° C. at a temperature lowering rate of 0.5 ° C./min, the sample is held for 20 minutes to precipitate the sample on the surface of the filler. Thereafter, the column temperature is sequentially raised at a rate of temperature rise of 20 ° C./min. From 40 ° C to 60 ° C, the temperature is increased at 10 ° C intervals, from 60 ° C to 75 ° C, the temperature is increased at 5 ° C intervals, from 75 ° C to 90 ° C, the temperature is increased at 3 ° C intervals, and from 90 ° C to 110 ° C. The temperature is increased at intervals of 1 ° C, and from 110 ° C to 120 ° C, the temperature is increased at intervals of 5 ° C. In addition, after hold | maintaining at each temperature for 21 minutes, it heats up and detects the density | concentration of the sample (ethylene polymer) eluted at each temperature. And the elution temperature-elution amount curve (FIG. 2) is measured from the value of the elution amount (% by mass) of the sample (ethylene polymer) and the temperature in the column (° C.) at that time, and the elution amount at each temperature, And the integrated amount of elution is obtained. More specifically, it can be measured by the method described in the examples.

  As means for adjusting the elution amount at 103 ° C. to 10% by mass or more and 20% by mass or less of the total elution amount, ethylene gas, a solvent, a catalyst, etc. are continuously supplied into the polymerization system, and the produced ethylene polymer In addition, the catalyst is continuously discharged with continuous polymerization, the catalyst is previously brought into contact with hydrogen and then added to the polymerization system, and the catalyst introduction line outlet is located as far as possible from the ethylene introduction line outlet. The ethylene polymer and the solvent are separated by a centrifugal separation method, and the amount of the solvent contained in the ethylene polymer before drying is set to 70% by mass or less based on the weight of the ethylene polymer. And carrying out after separating the solvent as much as possible by centrifugation.

  The integral elution amount of 40 ° C. or more and less than 96 ° C. measured by CFC of the ethylene polymer of the present embodiment is preferably 10% by mass or less, more preferably 9.5% by mass or less, More preferably, it is 9 mass% or less. Further, the integrated elution amount of 40 ° C. or more and less than 96 ° C. is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and further preferably 1.0% by mass or more. When the integrated elution amount of 40 ° C. or more and less than 96 ° C. is in the above range, the strength tends to be superior. The method for controlling the integrated elution amount of 40 ° C. or more and less than 96 ° C. to the above range is not particularly limited, but it is an ethylene homopolymer or a linear ethylene polymer, and further the elution amount of 103 ° C. It is possible to appropriately adjust the same means as the adjustment means.

  It is preferable that two or more elution peaks measured by CFC of the ethylene polymer of this embodiment exist. An ethylene polymer having excellent strength and dimensional accuracy preferably has an amorphous component that relaxes the molecular orientation and a crystalline component that maintains the shape, so that the low temperature derived from the amorphous component There are preferably two or more elution peaks, ie, a side elution peak (elution amount of less than 100 ° C.) and a high temperature side elution peak derived from a crystalline component (elution amount of 100 ° C. or more).

  Moreover, the integral elution amount of 96 ° C. or more and less than 100 ° C., which is the low temperature side elution peak, is 55% by mass or less of the total elution amount, and the integral elution amount of 100 ° C. or more and less than 104 ° C., which is the high temperature side elution peak. Preferably, the integrated elution amount at 96 ° C. or higher and lower than 100 ° C. is 54% by mass or lower, and the integrated elution amount at 100 ° C. or higher and lower than 104 ° C. is 36% by mass or higher. More preferably, the integral elution amount of 96 ° C. or more and less than 100 ° C. is 53% by mass or less, and the integral elution amount of 100 ° C. or more and less than 104 ° C. is 37% by mass or more. The integral elution amount of 96 ° C. or more and less than 100 ° C. is preferably 40% by mass or more, more preferably 41% by mass or more, and further preferably 42% by mass or more. The integrated elution amount at 100 ° C. or higher and lower than 104 ° C. is preferably 50% by mass or less, more preferably 49% by mass or less, and still more preferably 48% by mass or less. The integrated elution amount of 96 ° C. or more and less than 100 ° C. and the integrated elution amount of 100 ° C. or more and less than 104 ° C. are within the above ranges, so that an ethylene polymer having more excellent strength and dimensional accuracy, and strength, It tends to be a stretched molded product, a microporous membrane, and a battery separator having excellent dimensional accuracy. The method for controlling the integral elution amount of 96 ° C. or more and less than 100 ° C. and the integral elution amount of 100 ° C. or more and less than 104 ° C. to the above range is not particularly limited, but an ethylene homopolymer or a linear ethylene polymer In addition, it is possible to appropriately adjust the same means as the above-described adjusting means for the elution amount of 103 ° C.

  Although it does not specifically limit as an ethylene polymer of this embodiment, The copolymer of ethylene homopolymer or ethylene and another comonomer is mentioned. Although it does not specifically limit as another comonomer, For example, an alpha olefin and a vinyl compound are mentioned. Although it does not specifically limit as said alpha olefin, For example, C3-C20 alpha olefin is mentioned, Specifically, a propylene, 1-butene, 4-methyl-1- pentene, 1-hexene, Examples include 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, and 1-tetradecene. Furthermore, the vinyl compound is not particularly limited, and examples thereof include vinylcyclohexane, styrene and derivatives thereof. Further, if necessary, non-conjugated polyenes such as 1,5-hexadiene and 1,7-octadiene can be used as another comonomer. The copolymer may be a ternary random polymer. Another comonomer may be used individually by 1 type, and may use 2 or more types together.

  The ethylene polymer is preferably a homopolymer from the viewpoint of heat resistance. When the ethylene polymer contains a copolymer of ethylene and another comonomer, it is preferable to insert the comonomer in such a range that the heat resistance characteristics do not deteriorate. Specifically, the molar ratio of ethylene in the copolymer is preferably 50% or more and less than 100%, more preferably 80% or more and less than 100%, and still more preferably 90% or more and 100%. Is less than. The comonomer amount of the ethylene polymer can be confirmed by infrared analysis, NMR, or the like.

  Although the ethylene polymer of this embodiment is not specifically limited, It is preferable that it is linear. By being linear, the amount of the crystalline component is increased, and the heat resistance tends to be improved. The “linear ethylene polymer” refers to a polymer chain in which 10 or more long-chain (number average molecular weight 2,000 or more) branched chains do not exist. The branched chain of the ethylene polymer can be confirmed by infrared analysis, NMR, or the like. Examples of the references include polymer 30 volume July issue (1981) 545, introduction to plastic analysis (Maruzen Publishing) and the like.

Although the ethylene polymer of this embodiment is not specifically limited, It is preferable that a high density polyethylene is included. The density of the high-density polyethylene that can be contained is preferably 940 kg / cm ³ or more and 980 kg / cm ³ or less, more preferably 945 kg / m ³ or more and 980 kg / cm ³ or less, from the viewpoint of increasing the amount of the crystalline component. More preferably, it is 950 kg / m ³ or more and 980 kg / cm ³ or less. Although it does not specifically limit as a high density polyethylene, For example, an ethylene homopolymer (no comonomer) is mentioned. As the content of such high-density polyethylene increases, the amount of CFC eluted at 103 ° C. or more tends to increase, and a copolymer can be included in the above range of the CFC of this embodiment.

  The component having a molecular weight of 1,000,000 or more in terms of polyethylene of the ethylene polymer of the present embodiment is preferably 10% by mass or less, more preferably 9.8% by mass or less, and further preferably 9.5% by mass. It is as follows. The component having a molecular weight of 1,000,000 or more in terms of polyethylene is preferably 0.5% by mass or more, more preferably 1.0% by mass or more, and further preferably 1.5% by mass or more. is there. When the content of the component having a molecular weight of 1,000,000 or more in terms of polyethylene is in the above range, it tends to be more excellent in moldability. The amount of the component having a molecular weight of 1,000,000 or more in terms of polyethylene can be adjusted by allowing hydrogen to be present in the polymerization system or changing the polymerization temperature. By adding hydrogen as a chain transfer agent in the polymerization system, the molecular weight can be controlled within an appropriate range.

  The melting point (Tm) measured by a differential scanning calorimeter (DSC) of the ethylene polymer of this embodiment is preferably 133 ° C. or higher and 138 ° C. or lower, more preferably 134 ° C. or higher and 138 ° C. or lower, and still more preferably. Is 135 ° C. or higher and 138 ° C. or lower. When the melting point (Tm) is in the above range, it tends to be more excellent when used in a high temperature environment. In addition, melting | fusing point can be measured by the method as described in an Example. The melting point can be controlled by the type and amount of comonomer, the molecular weight of the ethylene polymer, and the like.

  The residual catalyst ash content of the ethylene polymer of this embodiment is preferably 50 ppm or less, more preferably 45 ppm, and even more preferably 40 ppm or less. Further, the smaller the residual catalyst ash content, the better. When the residual catalyst ash content is in the above range, the heat resistance tends to be superior. Here, “residual catalyst ash” refers to the total amount of Al, Mg, Ti, Zr, Cr and Cl. The residual catalyst ash can be measured by the method described in the examples. In order to control the residual catalyst ash to a low level, in the following ethylene polymer production method, the ethylene polymer and the solvent are separated by a centrifugal separation method.

[Catalyst component]
The catalyst component used for the production of the ethylene polymer of this embodiment is not particularly limited, and the ethylene polymer of this embodiment can be produced using a Ziegler-Natta catalyst, a metallocene catalyst, or the like.

Here, the Ziegler-Natta catalyst will be described. The Ziegler-Natta catalyst is a catalyst comprising a solid catalyst component [A] and an organometallic compound component [B], and the solid catalyst component [A] is soluble in the inert hydrocarbon solvent represented by Formula 1. What is the catalyst for olefin polymerization manufactured by making the organomagnesium compound (A-1) which is and the titanium compound (A-2) represented by Formula 2 react is preferable.
(A-1): (M ¹ ) _α (Mg) _β (R ² ) _a (R ³ ) _b Y ¹ _c Formula 1
(In the formula, M ¹ is a metal atom belonging to the group consisting of Groups 12, 13 and 14 of the periodic table, R ² and R ³ are hydrocarbon groups having 2 to 20 carbon atoms, Y ¹ is alkoxy, siloxy, allyloxy, amino, amide, —N═C—R ⁴ , R ⁵ , —SR ⁶ (where R ⁴ , R ^5, and R ⁶ are hydrocarbon groups having 1 to 20 carbon atoms. In the case where c is 2, Y ¹ may be different from each other.), A β-keto acid residue, and α, β, a, b, and c satisfy the following relationship: Real number 0 ≦ α, 0 <β, 0 ≦ a, 0 ≦ b, 0 ≦ c, 0 <a + b, 0 ≦ b / (α + β) ≦ 2, nα + 2β = a + b + c (where n is M ¹ Represents the valence.))
(A-2): Ti (OR ⁷ ) _d X ¹ _(4-d) Equation 2
(In the formula, d is a real number of 0 or more and 4 or less, R ⁷ is a hydrocarbon group of 1 to 20 carbon atoms, and X ¹ is a halogen atom.)

  In addition, although it does not specifically limit as an inert hydrocarbon solvent used for reaction of (A-1) and (A-2), Specifically, aliphatic hydrocarbons, such as butane, pentane, hexane, heptane; And aromatic hydrocarbons such as benzene, toluene and xylene; and alicyclic hydrocarbons such as cyclopentane, cyclohexane, methylcyclohexane and decalin.

  First, (A-1) will be described. (A-1) is shown as a complex form of organomagnesium soluble in an inert hydrocarbon solvent, but includes all dihydrocarbylmagnesium compounds and complexes of this compound with other metal compounds. Is. The relational expression nα + 2β = a + b + c of the symbols α, β, a, b, c indicates the stoichiometry between the valence of the metal atom and the substituent.

In Formula 1, the hydrocarbon group having 2 to 20 carbon atoms represented by R ² and R ³ is not particularly limited, and is specifically an alkyl group, a cycloalkyl group, or an aryl group, for example, ethyl Propyl, butyl, propyl, hexyl, octyl, decyl, cyclohexyl, phenyl group and the like. Of these, an alkyl group is preferable. When α> 0, as the metal atom M ¹ , a metal atom belonging to the group consisting of Groups 12, 13, and 14 of the periodic table can be used, and examples thereof include zinc, boron, and aluminum. Of these, aluminum and zinc are preferable.

The ratio β / α of magnesium to the metal atom M ¹ is not particularly limited, but is preferably 0.1 or more and 30 or less, and more preferably 0.5 or more and 10 or less. When a predetermined organomagnesium compound with α = 0 is used, for example, when R ² is 1-methylpropyl or the like, it is soluble in an inert hydrocarbon solvent, and such a compound is also included in this embodiment. Gives favorable results. In Formula 1, it is preferable that R ² and R ^{3 in} the case of α = 0 satisfy any one of the following three groups (1), (2), and (3).

It is preferable that at least one of the groups (1) R ² and R ³ is a secondary or tertiary alkyl group having 4 to 6 carbon atoms, more preferably R ² and R ³ both have 4 carbon atoms. The alkyl group is 6 or less and at least one is a secondary or tertiary alkyl group.
Group (2) R ² and R ³ are preferably different alkyl groups having different carbon atoms, more preferably R ² is an alkyl group having 2 or 3 carbon atoms, and R ³ is the number of carbon atoms. 4 or more alkyl groups.
Preferably, at least one of the groups (3) R ² and R ³ is a hydrocarbon group having 6 or more carbon atoms, more preferably an alkyl having 12 or more when the number of carbon atoms contained in R ² and R ³ is added. Be a group.

  These groups are specifically shown below. Specific examples of the secondary or tertiary alkyl group having 4 to 6 carbon atoms in the group (1) include 1-methylpropyl, 2-methylpropyl, 1,1-dimethylethyl, 2-methylbutyl. , 2-ethylpropyl, 2,2-dimethylpropyl, 2-methylpentyl, 2-ethylbutyl, 2,2-dimethylbutyl, 2-methyl-2-ethylpropyl group and the like. Of these, a 1-methylpropyl group is preferable.

  In the group (2), the alkyl group having 2 or 3 carbon atoms is not particularly limited, and specific examples thereof include ethyl, 1-methylethyl, propyl group and the like. Of these, an ethyl group is preferable. Further, the alkyl group having 4 or more carbon atoms is not particularly limited, and specific examples include butyl, pentyl, hexyl, heptyl, octyl group and the like. Of these, butyl and hexyl groups are preferable.

  Furthermore, in the group (3), the hydrocarbon group having 6 or more carbon atoms is not particularly limited, and specific examples include hexyl, heptyl, octyl, nonyl, decyl, phenyl, 2-naphthyl group and the like. Among the hydrocarbon groups, an alkyl group is preferable, and among the alkyl groups, hexyl and octyl groups are more preferable.

In general, when the number of carbon atoms contained in an alkyl group increases, it tends to be soluble in an inert hydrocarbon solvent, and the viscosity of the solution tends to increase. Therefore, it is preferable in handling to use an appropriate long-chain alkyl group. The organomagnesium compound can be used by diluting with an inert hydrocarbon solvent, although a small amount of Lewis basic compound such as ether, ester, amine or the like may be contained or remain in the solution. It can be used without any problem.
It will now be described ^{Y 1.} In Formula 1, Y ¹ is alkoxy, siloxy, allyloxy, amino, amide, —N═C—R ⁴ , R ⁵ , —SR ⁶ (wherein R ⁴ , R ⁵ and R ⁶ are each independently 2 or more carbon atoms) Represents a hydrocarbon group of 20 or less), or a β-keto acid residue.

The hydrocarbon group represented by R ⁴ , R ⁵ and R ⁶ in Formula 1 is preferably an alkyl group or aryl group having 1 to 12 carbon atoms, more preferably an alkyl group or aryl group having 3 to 10 carbon atoms. . Although not particularly limited, specifically, for example, methyl, ethyl, propyl, 1-methylethyl, butyl, 1-methylpropyl, 1,1-dimethylethyl, pentyl, hexyl, 2-methylpentyl, 2-ethylbutyl, Examples include 2-ethylpentyl, 2-ethylhexyl, 2-ethyl-4-methylpentyl, 2-propylheptyl, 2-ethyl-5-methyloctyl, octyl, nonyl, decyl, phenyl, naphthyl groups and the like. Of these, butyl, 1-methylpropyl, 2-methylpentyl and 2-ethylhexyl groups are preferred.

In Formula 1, Y ¹ is preferably an alkoxy group or a siloxy group. Although it does not specifically limit as an alkoxy group, Specifically, methoxy, ethoxy, propoxy, 1-methylethoxy, butoxy, 1-methylpropoxy, 1,1-dimethylethoxy, pentoxy, hexoxy, 2-methylpentoxy, 2-ethylbutoxy, 2-ethylpentoxy, 2-ethylhexoxy, 2-ethyl-4-methylpentoxy, 2-propylheptoxy, 2-ethyl-5-methyloctoxy, octoxy, phenoxy, naphthoxy group Is preferred. Of these, butoxy, 1-methylpropoxy, 2-methylpentoxy and 2-ethylhexoxy groups are more preferable. The siloxy group is not particularly limited. Specifically, hydrodimethylsiloxy, ethylhydromethylsiloxy, diethylhydrosiloxy, trimethylsiloxy, ethyldimethylsiloxy, diethylmethylsiloxy, triethylsiloxy groups and the like are preferable. Of these, hydrodimethylsiloxy, ethylhydromethylsiloxy, diethylhydrosiloxy, and trimethylsiloxy groups are more preferable.

In this embodiment, the synthesis method of (A-1) is not particularly limited, and is derived from the formula R ² MgX ¹ and the formula R ² ₂ Mg (R ² has the above-mentioned meaning and X ¹ is halogen). An organomagnesium compound belonging to the group, and the formulas M ¹ R ³ _n and M ¹ R ³ _(n-1) H (M ¹ and R ³ have the above-mentioned meanings, and n represents the valence of M ¹ ). An organometallic compound belonging to the group consisting of is reacted in an inert hydrocarbon solvent at 25 ° C. or higher and 150 ° C. or lower, and if necessary, the formula Y ¹ -H (Y ¹ is as defined above). in reacting a compound represented by, or can be synthesized by reacting an organic magnesium compound and / or an organoaluminum compound having a functional group represented by Y ^1. Among these, when the organomagnesium compound soluble in the inert hydrocarbon solvent is reacted with the compound represented by the formula Y ¹ -H, the order of the reaction is not particularly limited, and the formula Y ^{1 is} contained in the organomagnesium compound. Either a method of adding a compound represented by —H, a method of adding an organomagnesium compound to a compound represented by the formula Y ¹ —H, or a method of adding both at the same time can be used. it can.

In this embodiment, the range of the molar composition ratio c / (α + β) of Y ¹ with respect to all metal atoms in (A-1) is 0 ≦ c / (α + β) ≦ 2, and 0 ≦ c / (α + β) <1. It is preferable that When the molar composition ratio of Y ^{1 to} all metal atoms is 2 or less, the reactivity of (A-1) to (A-2) tends to be improved.

Next, (A-2) will be described. (A-2) is a titanium compound represented by Formula 2.
(A-2): Ti (OR ⁷ ) _d X ¹ _(4-d) Equation 2
(In the formula, d is a real number of 0 or more and 4 or less, R ⁷ is a hydrocarbon group of 1 to 20 carbon atoms, and X ¹ is a halogen atom.)

In the above formula 2, d is preferably 0 or more and 1 or less, and more preferably d is 0. Further, the hydrocarbon group represented by R ⁷ in Formula 2 is not particularly limited, and specifically, methyl, ethyl, propyl, butyl, pentyl, hexyl, 2-ethylhexyl, heptyl, octyl, decyl, allyl An aliphatic hydrocarbon group such as a group; an alicyclic hydrocarbon group such as a cyclohexyl, 2-methylcyclohexyl, or cyclopentyl group; an aromatic hydrocarbon group such as a phenyl or naphthyl group; Among these, an aliphatic hydrocarbon group is preferable. The halogen represented by X ^1, chlorine, bromine, and iodine. Of these, chlorine is preferred. In the present embodiment, (A-2) is more preferably titanium tetrachloride. In this embodiment, it is possible to use a mixture of two or more compounds selected from the above.

  Next, the reaction between (A-1) and (A-2) will be described. The reaction is preferably performed in an inert hydrocarbon solvent, and more preferably in an aliphatic hydrocarbon solvent such as hexane or heptane. The molar ratio of (A-1) to (A-2) in the above reaction is not particularly limited, but the molar ratio of Ti atoms contained in (A-2) to Mg atoms contained in (A-1) ( Ti / Mg) is preferably 0.1 or more and 10 or less, and more preferably 0.3 or more and 3 or less. Although it does not specifically limit about reaction temperature, It is preferable to carry out in the range of -80 degreeC or more and 150 degrees C or less, and it is more preferable to carry out in the range of -40 degreeC-100 degreeC. There is no restriction | limiting in particular in the addition order of (A-1) and (A-2), (A-2) is added following (A-1), (A-1) following (A-2) Any method of adding (A-1) and (A-2) at the same time is possible, but the method of simultaneously adding (A-1) and (A-2) is preferred. In the present embodiment, the solid catalyst component [A] obtained by the above reaction is used as a slurry solution using an inert hydrocarbon solvent.

Another example of the Ziegler-Natta catalyst component used in the present embodiment includes a solid catalyst component [C] and an organometallic compound component [B], and the solid catalyst component [C] is represented by Formula 3. A carrier (C-3) prepared by reacting an organomagnesium compound (C-1) that is soluble in an inert hydrocarbon solvent with a chlorinating agent (C-2) represented by formula 4 contains An olefin polymerization catalyst produced by supporting an organomagnesium compound (C-4) soluble in an inert hydrocarbon solvent represented by the formula (I) and a titanium compound (C-5) represented by the formula (6): preferable.
(C-1): (M ² ) _γ (Mg) _δ (R ⁸ ) _e (R ⁹ ) _f (OR ¹⁰ ) _g.
(In the formula, M ² is a metal atom belonging to the group consisting of Groups 12, 13 and 14 of the periodic table, and R ⁸ , R ⁹ and R ¹⁰ are each a hydrocarbon having 2 to 20 carbon atoms. Γ, δ, e, f, and g are real numbers that satisfy the following relationships: 0 ≦ γ, 0 <δ, 0 ≦ e, 0 ≦ f, 0 ≦ g, 0 <e + f, 0 ≦ g / (Γ + δ) ≦ 2, kγ + 2δ = e + f + g (where k represents the valence of M ² ))
(C-2): H _h SiCl _i R ¹¹ _{(4- (h + i))} Formula 4
(Wherein R ¹¹ is a hydrocarbon group having 1 to 12 carbon atoms, and h and i are real numbers satisfying the following relationship: 0 <h, 0 <i, 0 <h + i ≦ 4)
(C-4): (M ¹ ) _α (Mg) _β (R ² ) _a (R ³ ) _b Y ¹ _c Formula 5
(In the formula, M ¹ is a metal atom belonging to the group consisting of Groups 12, 13 and 14 of the periodic table, R ² and R ³ are hydrocarbon groups having 2 to 20 carbon atoms, Y ¹ is alkoxy, siloxy, allyloxy, amino, amide, —N═C—R ⁴ , R ⁵ , —SR ⁶ (where R ⁴ , R ⁵ and R ⁶ are hydrocarbon groups having 1 to 20 carbon atoms. In the case where c is 2, Y ¹ may be different from each other.), A β-keto acid residue, and α, β, a, b, and c satisfy the following relationship: Real number 0 ≦ α, 0 <β, 0 ≦ a, 0 ≦ b, 0 ≦ c, 0 <a + b, 0 ≦ b / (α + β) ≦ 2, nα + 2β = a + b + c (where n is M ¹ Represents the valence.))
(C-5): Ti (OR ⁷ ) _d X ¹ _(4-d) Formula 6
(In the formula, d is a real number of 0 or more and 4 or less, R ⁷ is a hydrocarbon group of 1 to 20 carbon atoms, and X ¹ is a halogen atom.)

  First, (C-1) will be described. (C-1) is shown as a complex form of organomagnesium soluble in an inert hydrocarbon solvent, but includes all dihydrocarbylmagnesium compounds and complexes of this compound with other metal compounds Is. The relational expression kγ + 2δ = e + f + g of the symbols γ, δ, e, f, and g in Formula 3 indicates the stoichiometry between the valence of the metal atom and the substituent.

In the above formula, the hydrocarbon group represented by R ⁸ to R ⁹ is not particularly limited, but specifically, it is an alkyl group, a cycloalkyl group or an aryl group, for example, methyl, ethyl, propyl, butyl. Propyl, hexyl, octyl, decyl, cyclohexyl, phenyl group and the like. Of these, preferably R ⁸ and R ⁹ are each an alkyl group. When α> 0, the metal atom M ² can be a metal atom belonging to the group consisting of Group 12, Group 13, and Group 14 of the Periodic Table, and examples thereof include zinc, boron, and aluminum. Of these, aluminum and zinc are preferable.

The ratio δ / γ of magnesium to metal atom M ² is not particularly limited, but is preferably 0.1 or more and 30 or less, and more preferably 0.5 or more and 10 or less. When a predetermined organomagnesium compound with γ = 0 is used, for example, when R ⁸ is 1-methylpropyl or the like, it is soluble in an inert hydrocarbon solvent, and such a compound is also included in this embodiment. Gives favorable results. In Formula 3, R ⁸ and R ⁹ when γ = 0 are preferably any one of the following three groups (1), (2), and (3).

In the group (1), at least one of R ⁸ and R ⁹ is preferably a secondary or tertiary alkyl group having 4 to 6 carbon atoms, more preferably R ⁸ and R ⁹ are both 4 to 6 carbon atoms. And at least one is a secondary or tertiary alkyl group.
Group (2) R ⁸ and R ⁹ are preferably alkyl groups having different carbon numbers, more preferably R ⁸ is an alkyl group having 2 or 3 carbon atoms, and R ⁹ is 4 or more carbon atoms. Must be an alkyl group.
In the group (3), at least one of R ⁸ and R ⁹ is preferably a hydrocarbon group having 6 or more carbon atoms, more preferably an alkyl group in which the sum of carbon atoms contained in R ⁸ and R ⁹ is 12 or more. There is.

  Hereinafter, these groups are specifically shown. Specific examples of the secondary or tertiary alkyl group having 4 to 6 carbon atoms in the group (1) include 1-methylpropyl, 2-methylpropyl, 1,1-dimethylethyl, 2-methylbutyl, Examples include 2-ethylpropyl, 2,2-dimethylpropyl, 2-methylpentyl, 2-ethylbutyl, 2,2-dimethylbutyl, and 2-methyl-2-ethylpropyl group. Of these, a 1-methylpropyl group is preferable.

  In group (2), examples of the alkyl group having 2 or 3 carbon atoms include ethyl, 1-methylethyl, and propyl groups. Among these, an ethyl group is preferable. Further, the alkyl group having 4 or more carbon atoms is not particularly limited, and specific examples thereof include butyl, pentyl, hexyl, heptyl, octyl group and the like. Of these, butyl and hexyl groups are preferable.

  Furthermore, in the group (3), the hydrocarbon group having 6 or more carbon atoms is not particularly limited, and specific examples include hexyl, heptyl, octyl, nonyl, decyl, phenyl, 2-naphthyl group and the like. Among the hydrocarbon groups, an alkyl group is preferable, and among the alkyl groups, hexyl and octyl groups are more preferable.

  In general, when the number of carbon atoms contained in the alkyl group increases, it tends to be soluble in an inert hydrocarbon solvent, and the viscosity of the solution tends to increase. Therefore, it is preferable in handling to use an appropriate long-chain alkyl group. In addition, although the said organomagnesium compound is used as an inert hydrocarbon solution, even if trace amount of Lewis basic compounds, such as ether, ester, an amine, are contained in this solution, it can be used without any problem.

Next, the alkoxy group (OR ¹⁰ ) will be described. The hydrocarbon group represented by R ¹⁰ is preferably an alkyl group or aryl group having 1 to 12 carbon atoms, and more preferably an alkyl group or aryl group having 3 to 10 carbon atoms. R ¹⁰ is not particularly limited, and specifically, methyl, ethyl, propyl, 1-methylethyl, butyl, 1-methylpropyl, 1,1-dimethylethyl, pentyl, hexyl, 2-methylpentyl, 2 -Ethylbutyl, 2-ethylpentyl, 2-ethylhexyl, 2-ethyl-4-methylpentyl, 2-propylheptyl, 2-ethyl-5-methyloctyl, octyl, nonyl, decyl, phenyl, naphthyl groups and the like can be mentioned. Of these, butyl, 1-methylpropyl, 2-methylpentyl and 2-ethylhexyl groups are preferred.

In this embodiment, the (C-1) is not particularly limited to the synthesis method, wherein ^R 8 MgX ¹ and wherein ^{R ₈} 2 Mg ^(R ₈ have the meaning described above, ^{X 1} is a halogen atom. And an organometallic compound belonging to the group consisting of formula M ² R ⁹ _k and formula M ² R ⁹ _(k-1) H (M ² , R ⁹ and k are as defined above) In an inert hydrocarbon solvent at a temperature of 25 ° C. or higher and 150 ° C. or lower, and if necessary, subsequently has a hydrocarbon group represented by R ⁹ (R ⁹ has the above-mentioned meaning). A method of reacting with an alkoxymagnesium compound having a hydrocarbon group represented by R ⁹ and / or an alkoxyaluminum compound soluble in an alcohol or an inert hydrocarbon solvent is preferred.

  Among these, when reacting an organomagnesium compound soluble in an inert hydrocarbon solvent with an alcohol, the order of the reaction is not particularly limited, and a method of adding alcohol to the organomagnesium compound, organomagnesium in the alcohol. Either a method of adding a compound or a method of adding both at the same time can be used. In the present embodiment, the reaction ratio between the organomagnesium compound soluble in the inert hydrocarbon solvent and the alcohol is not particularly limited. However, as a result of the reaction, the alkoxy group-containing organomagnesium compound has an alkoxy group with respect to all metal atoms. The molar composition ratio g / (γ + δ) is 0 ≦ g / (γ + δ) ≦ 2, and preferably 0 ≦ g / (γ + δ) <1.

Next, (C-2) will be described. (C-2) is represented by Formula 4, and at least one is a silicon chloride compound having a Si—H bond.
(C-2): H _h SiCl _i R ¹¹ _{(4- (h + i))} Equation 4
(Wherein R ¹¹ is a hydrocarbon group having 1 to 12 carbon atoms, and h and i are real numbers satisfying the following relationship: 0 <h, 0 <i, 0 <h + i ≦ 4)

The hydrocarbon group represented by R ¹¹ in Formula 4 is not particularly limited, and specific examples include an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group such as methyl, ethyl, and the like. Propyl, 1-methylethyl, butyl, pentyl, hexyl, octyl, decyl, cyclohexyl, phenyl group and the like. Among these, an alkyl group having 1 to 10 carbon atoms is preferable, and an alkyl group having 1 to 3 carbon atoms such as methyl, ethyl, propyl, and 1-methylethyl group is more preferable. H and i are numbers greater than 0 satisfying the relationship of h + i ≦ 4, and i is preferably 2 or more and 3 or less.

These compounds are not particularly limited, _{specifically, HSiCl 3, HSiCl 2 CH 3} , HSiCl 2 C 2 H 5, HSiCl 2 (C 3 H 7), HSiCl 2 (2-C 3 H 7) , HSiCl ₂ (C ₄ H ₉ ), HSiCl ₂ (C ₆ H ₅ ), HSiCl ₂ (4-Cl—C ₆ H ₄ ), HSiCl ₂ (CH═CH ₂ ), HSiCl ₂ (CH ₂ C ₆ H ₅₎ ), HSiCl ₂ (1-C ₁₀ H ₇ ), HSiCl ₂ (CH ₂ CH═CH ₂ ), H ₂ SiCl (CH ₃ ), H ₂ SiCl (C ₂ H ₅ ), HSiCl (CH ₃ ) ₂ , HSiCl _{(C 2 H 5) 2,} HSiCl (CH 3) (2-C 3 H 7), HSiCl (CH 3) (C 6 H 5), HSiCl (C 6 H 5) 2 and the like. A silicon chloride compound composed of these compounds or a mixture of two or more selected from these compounds is used. Among these, HSiCl ₃ , HSiCl ₂ CH ₃ , HSiCl (CH ₃ ) ₂ and HSiCl ₂ (C ₃ H ₇ ) are preferable, and HSiCl ₃ and HSiCl ₂ CH ₃ are more preferable.

  Next, the reaction between (C-1) and (C-2) will be described. In the reaction, (C-2) is preliminarily used as an inert hydrocarbon solvent, chlorinated hydrocarbon such as 1,2-dichloroethane, o-dichlorobenzene and dichloromethane; ether-based medium such as diethyl ether and tetrahydrofuran; It is preferable to use after diluting with a mixed medium. Among these, an inert hydrocarbon solvent is more preferable in terms of catalyst performance. Although the reaction ratio of (C-1) and (C-2) is not particularly limited, the silicon atom contained in (C-2) with respect to 1 mol of magnesium atom contained in (C-1) is 0.01 mol or more and 100 mol. Or less, more preferably 0.1 mol or more and 10 mol or less.

  There is no restriction | limiting in particular about the reaction method of (C-1) and (C-2), The method of simultaneous addition made to react, introducing (C-1) and (C-2) into a reactor simultaneously, ( A method in which (C-1) is introduced into the reactor after C-2) is charged to the reactor in advance, or (C-2) is charged into the reactor after (C-1) is charged in the reactor in advance. Any of the methods of introduction can be used. Among these, the method of introducing (C-1) into the reactor after charging (C-2) into the reactor in advance is preferable. The carrier (C-3) obtained by the above reaction is preferably separated by filtration or decantation and then thoroughly washed with an inert hydrocarbon solvent to remove unreacted products or by-products. .

  Although it does not specifically limit about the reaction temperature of (C-1) and (C-2), It is preferable that it is 25 to 150 degreeC, It is more preferable that it is 30 to 120 degreeC, 40 degreeC or more More preferably, it is 100 ° C. or lower. In the method of simultaneous addition in which (C-1) and (C-2) are simultaneously introduced into the reactor and reacted, the temperature of the reactor is adjusted to a predetermined temperature in advance, The reaction temperature is preferably adjusted to the predetermined temperature by adjusting the temperature to the predetermined temperature. In the method in which (C-1) is introduced into the reactor after (C-2) is charged into the reactor in advance, the temperature of the reactor charged with the silicon chloride compound is adjusted to a predetermined temperature, and the organomagnesium The reaction temperature is preferably adjusted to a predetermined temperature by adjusting the temperature in the reactor to a predetermined temperature while introducing the compound into the reactor. In the method of introducing (C-2) into the reactor after charging (C-1) into the reactor in advance, the temperature of the reactor charged with (C-1) is adjusted to a predetermined temperature, The reaction temperature is adjusted to a predetermined temperature by adjusting the temperature in the reactor to a predetermined temperature while introducing -2) into the reactor.

Next, the organomagnesium compound (C-4) will be described. (C-4) is represented by Formula 5 described above.
(C-4): (M ¹ ) _α (Mg) _β (R ² ) _a (R ³ ) _b Y ¹ _c Formula 5
(In the formula, M ¹ is a metal atom belonging to the group consisting of Groups 12, 13 and 14 of the periodic table, R ² and R ³ are hydrocarbon groups having 2 to 20 carbon atoms, Y ¹ is alkoxy, siloxy, allyloxy, amino, amide, —N═C—R ⁴ , R ⁵ , —SR ⁶ (where R ⁴ , R ⁵ and R ⁶ are hydrocarbon groups having 1 to 20 carbon atoms. In the case where c is 2, Y ¹ may be different from each other.), A β-keto acid residue, and α, β, a, b, and c satisfy the following relationship: Real number 0 ≦ α, 0 <β, 0 ≦ a, 0 ≦ b, 0 <a + b, 0 ≦ b / (α + β) ≦ 2, nα + 2β = a + b + c (where n represents the valence of M ¹ .))

  The amount of (C-4) used is preferably 0.1 or more and 10 or less in terms of a molar ratio of magnesium atoms contained in (C-4) to titanium atoms contained in (C-5). More preferably, it is 5 or less.

  The temperature of the reaction between (C-4) and (C-5) is not particularly limited, but is preferably −80 ° C. or higher and 150 ° C. or lower, and more preferably −40 ° C. or higher and 100 ° C. or lower. preferable.

  The concentration at the time of using (C-4) is not particularly limited, but is preferably 0.1 mol / L or more and 2 mol / L or less based on the titanium atom contained in (C-4), 0.5 mol / L More preferably, it is 1.5 mol / L or less. In addition, it is preferable to use an inert hydrocarbon solvent for the dilution of (C-4).

  The order of addition of (C-4) and (C-5) to (C-3) is not particularly limited, and (C-5) is added following (C-4), following (C-5). (C-4) and (C-4) and (C-5) can be added at the same time. Among these, the method of adding (C-4) and (C-5) simultaneously is preferable. The reaction between (C-4) and (C-5) is carried out in an inert hydrocarbon solvent, but it is preferable to use an aliphatic hydrocarbon solvent such as hexane or heptane. The catalyst thus obtained is used as a slurry solution using an inert hydrocarbon solvent.

Next, (C-5) will be described. In the present embodiment, (C-5) is a titanium compound represented by Formula 2 described above.
(C-5): Ti (OR ⁷ ) _d X ¹ _(4-d) Equation 6
(In the formula, d is a real number of 0 or more and 4 or less, R ⁷ is a hydrocarbon group of 1 to 20 carbon atoms, and X ¹ is a halogen atom.)

The hydrocarbon group represented by R ⁷ in Formula 6 is not particularly limited, and specifically, methyl, ethyl, propyl, butyl, pentyl, hexyl, 2-ethylhexyl, heptyl, octyl, decyl, allyl group, and the like An aliphatic hydrocarbon group such as cyclohexyl, 2-methylcyclohexyl and cyclopentyl groups; and an aromatic hydrocarbon group such as phenyl and naphthyl groups. Among these, an aliphatic hydrocarbon group is preferable. The halogen represented by X ¹ is not particularly limited, and specific examples include chlorine, bromine and iodine. Of these, chlorine is preferred. (C-5) selected from the above may be used singly or in combination of two or more.

  Although it does not specifically limit as the usage-amount of (C-5), 0.01-20 is preferable by molar ratio with respect to the magnesium atom contained in a support | carrier (C-3), and 0.05-10 is more preferable.

The reaction temperature of (C-5) is not particularly limited, but is preferably -80 ° C or higher and 150 ° C or lower, and more preferably -40 ° C or higher and 100 ° C or lower.
In the present embodiment, the method of supporting (C-5) with respect to (C-3) is not particularly limited, and a method of reacting excess (C-5) with (C-3), or a third method A method of efficiently supporting (C-5) by using components may be used, but a method of supporting by (C-5) and an organomagnesium compound (C-4) is preferable.

  Next, the organometallic compound component [B] in the present embodiment will be described. The solid catalyst component of this embodiment becomes a highly active polymerization catalyst by combining with the organometallic compound component [B]. The organometallic compound component [B] is sometimes called a “promoter”. The organometallic compound component [B] is preferably a compound containing a metal belonging to the group consisting of Group 1, Group 2, Group 12 and Group 13 of the Periodic Table, particularly organoaluminum compounds and / or Or an organomagnesium compound is preferable.

As the organoaluminum compound, a compound represented by the following formula 7 is preferably used alone or in combination.
AlR ¹² _j Z ¹ _(3-j) Equation 7
Wherein R ¹² is a hydrocarbon group having 1 to 20 carbon atoms, Z ¹ is a group belonging to the group consisting of hydrogen, halogen, alkoxy, allyloxy and siloxy groups, and j is a number of 2 to 3 .)

In the above formula 7, the hydrocarbon group having 1 to 20 carbon atoms represented by R ¹² is not particularly limited. Specifically, the hydrocarbon group is an aliphatic hydrocarbon, an aromatic hydrocarbon, or an alicyclic hydrocarbon. For example, trimethylaluminum, triethylaluminum, tripropylaluminum, tributylaluminum, tri (2-methylpropyl) aluminum (or triisobutylaluminum), tripentylaluminum, tri (3-methylbutyl) aluminum, trihexyl Trialkylaluminum such as aluminum, trioctylaluminum, tridecylaluminum; diethylaluminum chloride, ethylaluminum dichloride, bis (2-methylpropyl) aluminum chloride, ethylaluminum sesquichloride, di Aluminum halide compounds such as ethylaluminum bromide; alkoxyaluminum compounds such as diethylaluminum ethoxide and bis (2-methylpropyl) aluminum butoxide; dimethylhydrosiloxyaluminum dimethyl, ethylmethylhydrosiloxyaluminum diethyl, ethyldimethylsiloxyaluminum diethyl and the like Siloxyaluminum compounds; and mixtures thereof are preferred. Among these, a trialkylaluminum compound is more preferable.

As the organomagnesium compound, an organomagnesium compound that is soluble in the inert hydrocarbon solvent represented by the above formula 3 is preferable.
(M ² ) _γ (Mg) _δ (R ⁸ ) _e (R ⁹ ) _f (OR ¹⁰ ) _g ...
(In the formula, M ² is a metal atom belonging to the group consisting of Groups 12, 13 and 14 of the periodic table, and R ⁸ , R ⁹ and R ¹⁰ are each a hydrocarbon having 2 to 20 carbon atoms. Γ, δ, e, f, and g are real numbers that satisfy the following relationships: 0 ≦ γ, 0 <δ, 0 ≦ e, 0 ≦ f, 0 ≦ g, 0 <e + f, 0 ≦ g / (Γ + δ) ≦ 2, kγ + 2δ = e + f + g (where k represents the valence of M ² ))

This organomagnesium compound is shown as a complex form of organomagnesium soluble in an inert hydrocarbon solvent, but encompasses all dialkylmagnesium compounds and complexes of this compound with other metal compounds. is there. γ, δ, e, f, g, M ² , R ⁸ , R ⁹ , and OR ¹⁰ are as described above. However, since this organomagnesium compound preferably has higher solubility in an inert hydrocarbon solvent, β / α is preferably in the range of 0.5 to 10, and more preferably a compound in which M ² is aluminum.

  The method for adding the solid catalyst component and the organometallic compound component [B] to the polymerization system under the polymerization conditions is not particularly limited, and both may be added separately to the polymerization system, or both may be reacted in advance. You may make it add in a polymerization system, after making it. The ratio of the two to be combined is not particularly limited, but the organometallic compound component [B] is preferably 1 mmol or more and 3,000 mmol or less with respect to 1 g of the solid catalyst component.

[Method for producing ethylene polymer]
Examples of the polymerization method in the method for producing an ethylene polymer of the present embodiment include a method of (co) polymerizing ethylene or a monomer containing ethylene by a suspension polymerization method or a gas phase polymerization method. Among these, the suspension polymerization method that can efficiently remove the heat of polymerization is preferable. In the suspension polymerization method, an inert hydrocarbon medium can be used as a medium, and the olefin itself can also be used as a solvent.

  Although it does not specifically limit as said inert hydrocarbon medium, Specifically, Aliphatic hydrocarbons, such as propane, butane, isobutane, pentane, isopentane, hexane, heptane, octane, decane, dodecane, kerosene; cyclopentane, Examples thereof include alicyclic hydrocarbons such as cyclohexane and methylcyclopentane; aromatic hydrocarbons such as benzene, toluene and xylene; halogenated hydrocarbons such as ethyl chloride, chlorobenzene and dichloromethane, or mixtures thereof.

  The polymerization temperature in the method for producing an ethylene polymer of this embodiment is usually preferably 30 ° C. or higher and 100 ° C. or lower, more preferably 35 ° C. or higher and 90 ° C. or lower, and further preferably 40 ° C. or higher and 80 ° C. or lower. If the polymerization temperature is 30 ° C. or higher, industrially efficient production is possible. On the other hand, if the polymerization temperature is 100 ° C. or lower, stable operation can be continuously performed.

  The polymerization pressure in the method for producing an ethylene polymer of the present embodiment is usually preferably normal pressure or higher and 2 MPa or lower, more preferably 0.1 MPa or higher and 1.5 MPa or lower, and further preferably 0.1 MPa or higher and 1.0 MPa or lower. .

  The polymerization reaction can be carried out in any of batch, semi-continuous and continuous methods, but it is preferable to perform polymerization in a continuous manner. By continuously supplying ethylene gas, solvent, catalyst, etc. into the polymerization system and continuously discharging it together with the generated ethylene polymer, it becomes possible to suppress partial high temperature conditions due to rapid ethylene reaction. The inside of the polymerization system is further stabilized. When ethylene reacts in a uniform state in the system, the formation of branches, double bonds, etc. in the polymer chain is suppressed, or low molecular weight components and ultrahigh molecular weight polymers are produced by decomposition and crosslinking of the ethylene polymer. Is suppressed, and the crystalline component of the ethylene polymer is easily generated. This makes it easy to obtain a sufficient amount of crystalline component necessary for the strength of the film, microporous membrane, and the like. Therefore, a continuous system in which the inside of the polymerization system becomes more uniform is preferable. It is also possible to carry out the polymerization in two or more stages having different reaction conditions.

  The molecular weight of the ethylene polymer can be adjusted by, for example, allowing hydrogen to be present in the polymerization system or changing the polymerization temperature, as described in the specification of German Patent Publication No. 3127133. . By adding hydrogen as a chain transfer agent in the polymerization system, the molecular weight can be controlled within an appropriate range. When hydrogen in the polymerization system is added, the molar fraction of hydrogen is preferably 0 mol% or more and 30 mol% or less, more preferably 0 mol% or more and 25 mol% or less, and 0 mol% or more and 20 mol% or less. Is more preferable.

  Furthermore, it is preferable that hydrogen is added to the polymerization system from the catalyst introduction line after contacting with the catalyst in advance. Immediately after the catalyst is introduced into the polymerization system, the concentration of the catalyst near the outlet of the introduction line is high, and there is an increased possibility of partial high temperatures due to the rapid reaction of ethylene. By bringing the catalyst into contact before introduction, it is possible to suppress the initial activity of the catalyst, and it is also possible to suppress by-products and the like that hinder the generation of the crystalline component. Therefore, it is preferable to introduce hydrogen into the polymerization system in contact with the catalyst.

  For the same reason, the outlet of the catalyst introduction line in the polymerization system is preferably located as far as possible from the outlet of the ethylene introduction line. Specifically, ethylene may be introduced from the bottom of the polymerization solution, and the catalyst may be introduced from the middle between the liquid surface and the bottom of the polymerization solution.

  The solvent separation method in the method for producing an ethylene polymer of the present embodiment can be performed by a decantation method, a centrifugal separation method, a filter filtration method, or the like, but a centrifugal separation method with good separation efficiency between the ethylene polymer and the solvent is more preferable. The amount of the solvent contained in the ethylene polymer after the solvent separation is not particularly limited, but is 70% by mass or less, more preferably 60% by mass or less, further preferably 50% by mass or less, based on the weight of the ethylene polymer. is there. By removing the solvent by drying in a state where the amount of the solvent contained in the ethylene polymer is small, metal components and low molecular weight components contained in the solvent tend not to remain in the ethylene polymer. When these components do not remain, a crystalline component of the ethylene polymer is easily generated, so that a sufficient amount of the crystalline component necessary for the strength of a film, a microporous film, or the like is easily obtained. Therefore, it is preferable to separate the ethylene polymer and the solvent by a centrifugal separation method.

  The method for deactivating the catalyst used for synthesizing the ethylene polymer of the present embodiment is not particularly limited, but it is preferable to carry out after separating the ethylene polymer and the solvent. By introducing an agent for deactivating the catalyst after separation from the solvent, precipitation of low molecular weight components, catalyst components and the like contained in the solvent can be reduced.

  Examples of the agent that deactivates the catalyst system include oxygen, water, alcohols, glycols, phenols, carbon monoxide, carbon dioxide, ethers, carbonyl compounds, alkynes, and the like.

  The drying temperature in the method for producing an ethylene polymer of the present embodiment is usually preferably from 50 ° C. to 150 ° C., more preferably from 50 ° C. to 140 ° C., and further preferably from 50 ° C. to 130 ° C. If the drying temperature is 50 ° C. or higher, efficient drying is possible. On the other hand, if the drying temperature is 150 ° C. or lower, it is possible to dry in a state where the decomposition and crosslinking of the ethylene polymer are suppressed. In the present embodiment, in addition to the above components, other known components useful for the production of an ethylene polymer can be included.

[Additive]
Furthermore, the ethylene polymer of the present embodiment may contain additives such as a neutralizer, an antioxidant, and a light stabilizer.

  The neutralizing agent is used as a chlorine catcher contained in the ethylene polymer or a molding processing aid. Although it does not specifically limit as a neutralizing agent, Specifically, the stearate of alkaline-earth metals, such as calcium, magnesium, barium, is mentioned. Although content of a neutralizing agent is not specifically limited, It is 5000 ppm or less, More preferably, it is 4000 ppm or less, More preferably, it is 3000 ppm or less. In the ethylene polymer obtained by the slurry polymerization method using a metallocene catalyst, it is possible to exclude a halogen component from the catalyst components, and in this case, a neutralizing agent is unnecessary.

  Although it does not specifically limit as antioxidant, Specifically, dibutylhydroxytoluene, pentaeryristyl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], octadecyl-3 And phenolic antioxidants such as-(3,5-di-t-butyl-4-hydroxyphenyl) propionate. Although content of antioxidant is not specifically limited, 5,000 ppm or less is preferable, More preferably, it is 4,000 ppm or less, More preferably, it is 3,000 ppm or less.

  The light-resistant stabilizer is not particularly limited, and specifically, 2- (5-methyl-2-hydroxyphenyl) benzotriazole, 2- (3-t-butyl-5-methyl-2-hydroxyphenyl)- Benzotriazole light stabilizers such as 5-chlorobenzotriazole; bis (2,2,6,6-tetramethyl-4-piperidine) sebacate, poly [{6- (1,1,3,3-tetramethylbutyl ) Amino-1,3,5-triazine-2,4-diyl} {(2,2,6,6-tetramethyl-4-piperidyl) imino} hexamethylene {(2,2,6,6-tetramethyl) Hindered amine light stabilizers such as -4-piperidyl) imino}]. Although content of a light-resistant stabilizer is not specifically limited, It is 5000 ppm or less, More preferably, it is 4000 ppm or less, More preferably, it is 3000 ppm or less.

  The content of the additive contained in the ethylene polymer is determined by extracting the additive in the ethylene polymer by Soxhlet extraction using tetrahydrofuran (THF) for 6 hours, and separating and quantifying the extract by liquid chromatography. Can be sought.

  The ethylene polymer of the present embodiment can be blended with ethylene polymers having different viscosity average molecular weights, molecular weight distributions, etc., and other resins such as low density polyethylene, linear low density polyethylene, polypropylene, and polystyrene are blended. You can also Moreover, the ethylene polymer of this embodiment can be used conveniently even if it is a powder form or a pellet form.

[Usage]
The ethylene polymer obtained by the above can be applied to various uses by various processing methods. Since the molded body containing the ethylene polymer of the present embodiment is excellent in strength and dimensional accuracy, and is also excellent in heat resistance, it can be suitably used as a stretched molded body, a microporous film, or a battery separator. Examples of such molded bodies include secondary battery separators, particularly lithium ion secondary battery separators, high-strength fibers, microporous membranes, and gel spinning. As a specific method for producing the microporous membrane, there is a processing method through extrusion, stretching, extraction, and drying in an extruder equipped with a T-die in a wet method using a solvent. Such a microporous membrane can be suitably used for a secondary battery separator typified by a lithium ion secondary battery or a lead storage battery, particularly a lithium ion secondary battery separator.

  In addition, by taking advantage of the characteristics of high molecular weight ethylene polymer, such as abrasion resistance, high slidability, high strength, and high impact, by solid molding such as extrusion molding, press molding and cutting, Used for lining materials for gears, rolls, curtain rails, pachinko ball rails, lining sheets for storage silos such as grains, sliding coatings for rubber products, skis and ski soles, trucks and shovel cars, etc. Is mentioned. Moreover, it can be used for the molded object obtained by sintering an ethylene polymer, a filter, a dust trap material, etc.

  EXAMPLES Hereinafter, although this invention is demonstrated further in detail using an Example and a comparative example, this invention is not limited at all by the following examples.

[Reference Example] Catalyst synthesis example [Preparation of solid catalyst component [A]]
1,600 mL of hexane was added to an 8 L stainless steel autoclave sufficiently purged with nitrogen. While stirring at 10 ° C., 800 mL of 1 mol / L titanium tetrachloride hexane solution and 800 mL of hexane solution of organomagnesium compound represented by 1 mol / L composition formula AlMg ₅ (C ₄ H ₉ ) ₁₁ (OSiH) ₂ Added simultaneously over time. After the addition, the temperature was slowly raised and the reaction was continued at 10 ° C. for 1 hour. After completion of the reaction, 1600 mL of the supernatant was removed, and the solid catalyst component [A] was prepared by washing 5 times with 1,600 mL of hexane. The amount of titanium contained in 1 g of this solid catalyst component [A] was 3.05 mmol.

[Preparation of solid catalyst component [B]]
(1) (B-1) Synthesis of carrier Into a fully nitrogen-substituted 8 L stainless steel autoclave, 1,000 mL of a 2 mol / L hydroxytrichlorosilane hexane solution was charged and stirred at 65 ° C. with a composition formula of AlMg ₅ (C _{4 H 9) 11 (OC 4} H 9) hexane 2,550mL of organomagnesium compounds represented by ₂ (magnesium 2.68mol equivalent) was added dropwise over 4 hours, a further 1 hour stirring the reaction at 65 ° C. Was continued. After completion of the reaction, the supernatant was removed and washed 4 times with 1,800 mL of hexane. As a result of analyzing this solid ((B-1) support), magnesium contained per 1 g of the solid was 8.31 mmol.

(2) Preparation of solid catalyst component [B] (B-1) 110 mL of 1 mol / L titanium tetrachloride hexane solution and 1 mol / L composition while stirring at 10 ° C. in 1,970 mL of hexane slurry containing 110 g of support 110 mL of a hexane solution of an organomagnesium compound represented by the formula AlMg ₅ (C ₄ H ₉ ) ₁₁ (OSiH) ₂ was added simultaneously over 1 hour. After the addition, the reaction was continued at 10 ° C. for 1 hour. After completion of the reaction, 1100 mL of the supernatant was removed, and the solid catalyst component [B] was prepared by washing twice with 1,100 mL of hexane. The amount of titanium contained in 1 g of this solid catalyst component [B] was 0.75 mmol.

[Preparation of solid catalyst component [C]]
(1) (C-1) Preparation of Chromium Oxide Catalyst 4 mmol of chromium trioxide was dissolved in 80 mL of distilled water, and 20 g of silica (grade 952 manufactured by WR Grace and Company) was immersed in this solution. After stirring for a period of time, this slurry was heated to distill off water, followed by drying under reduced pressure at 120 ° C. for 10 hours, followed by firing with flowing dry air at 600 ° C. for 5 hours. A chromium oxide catalyst (C-1) containing 0% by mass was obtained.

(2) (C-2) Synthesis of organoaluminum compound Triethylaluminum 100 mmol, methylhydropolysiloxane (viscosity at 30 ° C .: 30 centistokes) 50 mmol (Si basis), hexane 150 mL were weighed in a glass pressure vessel under a nitrogen atmosphere. Then, the mixture was reacted for 24 hours at 50 ° C. with stirring using a magnetic stir bar to prepare an Al (C ₂ H ₅ ) _2.5 (OSi · H · CH ₃ · C ₂ H ₅ ) _0.5 hexane solution. Next, 100 mmol (Al standard) of this solution was weighed into a 200 mL flask under a nitrogen atmosphere, and a mixed solution of 50 mL of ethanol and 50 mL of hexane was added dropwise from a dropping funnel with ice-cooling and stirring. The reaction was carried out at temperature for 1 hour to prepare an Al (C ₂ H ₅ ) _2.0 (OC ₂ H ₅ ) _0.5 (OSi · H · CH ₃ · C ₂ H ₅ ) _0.5 hexane solution.

(3) Preparation of solid catalyst component [C] To 50 mg of the chromium oxide catalyst (C-1) synthesized in (1), 0.03 mmol (Al basis) of the organoaluminum compound (C-2) prepared in (2). In addition, it was reacted at room temperature for 1 hour to obtain a solid catalyst component [C].

[Example 1]
(Ethylene polymer polymerization process)
Hexane, ethylene, hydrogen, and catalyst were continuously supplied to a vessel type 300 L polymerization reactor equipped with a stirrer. The polymerization pressure was 0.5 MPa. The polymerization temperature was kept at 83 ° C. by jacket cooling. Hexane was fed from the bottom of the polymerizer at 40 L / hr. Solid catalyst component [A] and triisobutylaluminum were used as a cocatalyst. The solid catalyst component [A] was added at a rate of 0.2 g / hr from the middle between the liquid surface and the bottom of the polymerization vessel, and triisobutylaluminum was added at a rate of 10 mmol / hr from the middle between the liquid level and the bottom of the polymerization vessel. . The production rate of the ethylene polymer was 10 kg / hr. Hydrogen was continuously supplied by a pump so that the hydrogen concentration with respect to ethylene in the gas phase was 14 mol%. In addition, hydrogen was supplied from the catalyst introduction line in order to contact with the catalyst in advance, and ethylene was supplied from the bottom of the polymerization vessel. The catalytic activity was 80,000 g-PE / g-solid catalyst component [A]. The polymerization slurry was continuously drawn into a flash drum having a pressure of 0.05 Mpa and a temperature of 70 ° C. so that the level of the polymerization reactor was kept constant, and unreacted ethylene and hydrogen were separated.

  Next, the polymerization slurry was continuously sent to a centrifuge so that the level of the polymerization reactor was kept constant, and the polymer and other solvents were separated. At that time, the content of the solvent and the like with respect to the polymer was 45%.

  The separated ethylene polymer powder was dried while blowing nitrogen at 85 ° C. In this drying step, the catalyst and the cocatalyst were deactivated by spraying steam on the polymerized powder. To the obtained ethylene polymer powder, 1,500 ppm of calcium stearate (manufactured by Dainichi Chemical Co., Ltd., C60) was added and mixed uniformly using a Henschel mixer. The obtained ethylene polymer powder was removed by using a sieve having an opening of 425 μm and removing what did not pass through the sieve to obtain an ethylene polymer powder. The characteristics of the obtained ethylene polymer were measured by the method shown below. The results are shown in Table 1. FIG. 2 shows an elution temperature-elution amount curve obtained by CFC measurement.

(Method for producing microporous membrane)
To 100 parts by mass of ethylene polymer powder, 0.3 part by mass of pentaerythrityl-tetrakis- [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] as an antioxidant is added, and a tumbler is added. An ethylene polymer mixture was obtained by dry blending using a blender. The obtained ethylene polymer mixture was substituted with nitrogen, and then charged into a twin-screw extruder through a feeder under a nitrogen atmosphere. Further, 65 parts of liquid paraffin (P-350 (trademark) manufactured by Matsumura Oil Co., Ltd.) was injected into the extruder by side feed, kneaded at 200 ° C., extruded from a T-die installed at the tip of the extruder, and immediately The mixture was cooled and solidified with a cast roll cooled to 25 ° C. to form a gel sheet having a thickness of 1200 μm.

  The gel-like sheet was stretched 7 × 7 times at 120 ° C. using a simultaneous biaxial stretching machine, and then the stretched film was immersed in methyl ethyl ketone to extract and remove liquid paraffin, followed by drying. Furthermore, heat setting was performed at 125 ° C. for 3 minutes to obtain a microporous membrane. The physical properties of the obtained film were measured by the methods shown below. The results are shown in Table 1.

  As with the ethylene polymer, the properties of the microporous membrane were measured. The viscosity average molecular weight (Mv) was 237,000 g / mol, the molecular weight distribution (Mw / Mn) was 7.2, and measured by CFC. The elution amount at 103 ° C is 14.1% by mass of the total elution amount, the integrated elution amount at 40 ° C to less than 96 ° C is 8.2% by mass, and the integrated elution amount at 96 ° C to less than 100 ° C is the total elution amount. The integral elution amount of 50.2% by mass of the amount and not lower than 100 ° C. and lower than 104 ° C. was 39.2% by mass of the total elution amount. In this way, it is possible to confirm the ethylene polymer from the microporous membrane.

[Methods for measuring various properties and physical properties]
(1) Viscosity average molecular weight (Mv)
First, 20 mg of ethylene polymer was added to 20 mL of decalin (decahydronaphthalene) and stirred at 150 ° C. for 2 hours to dissolve the polymer. The drop time (t _s ) between the marked lines was measured using a Ubbelohde type viscometer for the solution in a thermostatic bath at 135 ° C. Similarly, three-point solutions were prepared by changing the weight of the ethylene polymer, and the drop time was measured. The falling time (t _b ) of only decalin without an ethylene polymer as a blank was measured. By plotting the reduced viscosity (η _sp / C) of the polymer determined according to the following equation, a linear expression of the concentration (C) (unit: g / dL) and the reduced viscosity (η _sp / C) of the polymer was derived. The intrinsic viscosity extrapolated to 0 ([η]) was determined.
_{η sp / C = (t s} / t b -1) / C ( unit: dL / g)
Next, using the following formula A, the viscosity average molecular weight (Mv) was calculated using the value of the intrinsic viscosity ([η]).
Mv = (5.34 × 10 ⁴ ) × [η] ^1.49 Formula A

(2) Molecular weight measurement For a sample solution prepared by introducing 15 mL of o-dichlorobenzene into 20 mg of an ethylene polymer and stirring at 150 ° C. for 1 hour, measurement of gel permeation chromatography (GPC) is performed under the following conditions. went. From the measurement results, the number average molecular weight (Mn), the weight average molecular weight (Mw), and the molecular weight distribution (Mw / Mn) were determined based on a calibration curve prepared using commercially available monodisperse polystyrene.
-Equipment: 150-C ALC / GPC manufactured by Waters
・ Detector: RI detector ・ Mobile phase: o-dichlorobenzene (for high performance liquid chromatograph)
Flow rate: 1.0 mL / min Column: One AT-807S manufactured by Shodex and two TSK-gelGMH-H6 manufactured by Tosoh were connected.
-Column temperature: 140 ° C

(3) Melting point (Tm)
A differential scanning calorimeter (Perkin Elmer DSC-7 type apparatus) was used and measured under the following conditions. 1) About 5 mg of a polymer sample was packed in an aluminum pan, heated to 200 ° C. at 200 ° C./min, and held at 200 ° C. for 5 minutes. 2) Next, the temperature was decreased from 200 ° C. to 50 ° C. at a rate of temperature decrease of 10 ° C./min, and held for 5 minutes after the temperature decrease was completed. 3) Next, the temperature was raised from 50 ° C. to 200 ° C. at a rate of 10 ° C./min. From the endothermic curve observed in the process of 3), the maximum temperature at the melting peak position was defined as the melting point (° C.).

(4) Residual catalyst ash (total content of Al, Mg, Ti, Zr, Cr and Cl)
0.2 g of sample was weighed in a Teflon (registered trademark) decomposition vessel, high-purity nitric acid was added, and after pressure decomposition with Milestone General's microwave decomposition apparatus ETHOS-TC, ultrapure water manufactured by Nihon Millipore was manufactured. Pure water purified with an apparatus and adjusted to a total volume of 50 mL was used as a test solution. Using the Thermocoupler Scientific Inductively Coupled Plasma Mass Spectrometer (ICP-MS) X Series 2, the internal standard method can be used to quantify Al, Mg, Ti, Zr, Cr, and Cl. went.

(5) CFC elution amount (TREF elution amount)
For the ethylene polymer, the elution temperature-elution amount curve by temperature rising elution fractionation (TREF) was measured as follows, and the elution amount and elution integral amount at each temperature were determined.
First, the column containing the packing was heated to 140 ° C., and a sample solution in which an ethylene polymer was dissolved in orthodichlorobenzene was introduced and held for 120 minutes. Next, the temperature of the column was lowered to 40 ° C. at a temperature lowering rate of 0.5 ° C./min, and then held for 20 minutes to deposit the sample on the surface of the packing material.

Thereafter, the column temperature was sequentially raised at a rate of temperature rise of 20 ° C./min. First, the temperature is increased from 40 ° C. to 60 ° C. at 10 ° C. intervals, from 60 ° C. to 75 ° C. at 5 ° C. intervals, from 75 ° C. to 90 ° C. at 3 ° C. intervals, from 90 ° C. to 110 ° C. The temperature was increased at 1 ° C intervals, and the temperature was increased from 110 ° C to 120 ° C at 5 ° C intervals. In addition, after holding the temperature at each temperature for 21 minutes, the temperature was raised, and the concentration of the sample (ethylene polymer) eluted at each temperature was detected. Then, an elution temperature-elution amount curve is measured from the value of the elution amount (mass%) of the sample (ethylene polymer) and the temperature in the column (° C.) at that time, and the elution amount and elution integration amount at each temperature. Asked. FIG. 1 shows a CFC temperature profile.
-Apparatus: Automated 3D analyzer CFC-2 manufactured by Polymer ChAR
Column: Stainless steel microball column (3/8 "o x d 150 mm)
Eluent: o-dichlorobenzene (for high performance liquid chromatograph)
Sample solution concentration: Sample (ethylene polymer) 20 mg / o-dichlorobenzene 20 mL
・ Injection volume: 0.5 mL
Pump flow rate: 1.0 mL / min Detector: Infrared spectrophotometer IR4 manufactured by Polymer ChAR
・ Detected wave number: 3.42 μm
-Sample dissolution conditions: 140 ° C x 120 min dissolution

(6) Film thickness The film thickness of the microporous film was measured at a room temperature of 23 ° C using a micro thickness gauge (type KBM (registered trademark)) manufactured by Toyo Seiki.

(7) Thermal contraction rate The microporous membrane was cut into a length of 10 mm and a length of 100 mm in the MD direction. The cut one was placed in a 125 ° C. hot air oven and heated for 15 minutes. The thermal contraction rate (%) was determined by the ratio of the contracted length to the original length (100 mm).

(8) Membrane state observation The heat shrinkage ratio before and after heat setting of the microporous membrane obtained by heat setting under the conditions of heat setting (temperature 130 ° C., heat setting time 90 seconds) and the state of the film Observed. The heat shrinkage rate was measured by the method (6).
-A sample having a thermal shrinkage rate of 3% or less and having no change in film thickness was marked as ◯.
-A sample having a thermal contraction rate of more than 3% and no change in film thickness was marked as Δ.
・ If the film was wrinkled, it was marked with x.

(9) Puncture strength Using a “KES-G5 Handy Compression Tester” (trademark) manufactured by Kato Tech, a puncture test was performed under the conditions of a radius of curvature of the needle tip of 0.5 mm and a puncture speed of 2 mm / sec. N) was measured.
・ If the piercing load exceeds 4.0, it was marked as ◎.
・ If the piercing load exceeds 3.5, it was rated as ○.
・ If the piercing load is 3.5 or less, it was marked as x.

[Example 2]
In the polymerization step, an ethylene polymer powder of Example 2 was obtained in the same manner as in Example 1 except that the solid catalyst component [B] was used without using the solid catalyst component [A]. The microporous membrane of Example 2 was obtained by the same operation as in Example 1.

[Example 3]
In the polymerization step, an ethylene polymer powder of Example 3 was obtained in the same manner as in Example 1 except that the hydrogen concentration was 5 mol%. The microporous membrane of Example 3 was obtained by the same operation as in Example 1.

[Example 4]
In the polymerization step, an ethylene polymer powder of Example 4 was obtained in the same manner as in Example 1 except that the hydrogen concentration was 12 mol% and triethylaluminum was used instead of triisobutylaluminum. The microporous membrane of Example 4 was obtained by the same operation as in Example 1.

[Comparative Example 1]
In the polymerization step, an ethylene polymer powder of Comparative Example 1 was obtained in the same manner as in Example 1 except that the hydrogen concentration was 25 mol%. The microporous membrane of Comparative Example 1 was obtained by the same operation as in Example 1.

[Comparative Example 2]
In the polymerization step, an ethylene polymer powder of Comparative Example 2 was obtained in the same manner as in Example 1 except that the hydrogen concentration was 10 mol%. The microporous membrane of Comparative Example 2 was obtained by the same operation as in Example 1.

[Comparative Example 3]
In the polymerization step, an ethylene polymer powder of Comparative Example 3 was obtained in the same manner as in Example 1 except that the polymerization temperature was 78 ° C. and the hydrogen concentration was 5 mol%. The microporous membrane of Comparative Example 3 was obtained by the same operation as in Example 1.

[Comparative Example 4]
In the polymerization step, an ethylene polymer powder of Comparative Example 4 was obtained in the same manner as in Example 1 except that instead of ethylene, a mixed gas of 97/3 mol% of ethylene and 1-butene was used. The microporous membrane of Comparative Example 4 was obtained by the same operation as in Example 1.

[Comparative Example 5]
An ethylene / hydrogen mixed gas (ethylene / hydrogen = 95/5 mol%) was supplied from the bottom of the polymerization vessel to a Bessel type 300 L polymerization reactor equipped with a stirrer containing 142 L (total amount) of hexane, and the polymerization pressure was 0.5 MPa. It was. By adding 0.25 mmol of triisobutylaluminum as a co-catalyst from the middle between the liquid surface and the bottom of the polymerization vessel, and then adding 0.2 g of the solid catalyst component [A] from the middle between the liquid surface and the bottom of the polymerization vessel. The polymerization reaction was started. During the polymerization reaction, an ethylene / hydrogen mixed gas was constantly supplied to keep the polymerization pressure at 0.5 MPa. The polymerization temperature was kept from 82 ° C. (polymerization start temperature) to 85 ° C. (maximum temperature reached) by jacket cooling. After 3 hours, the polymerization reactor was depressurized to remove unreacted ethylene and hydrogen, and the inside of the polymerization system was replaced with nitrogen. Thereafter, the polymerization slurry temperature was lowered to 45 ° C., and a small amount of methanol was added to completely stop the polymerization reaction. The catalytic activity was 50,000 g-PE / g-solid catalyst component [A].

  Next, the polymerization slurry was continuously sent to a centrifuge to separate the polymer from other solvents. At that time, the content of the solvent or the like with respect to the polymer was 48%. Subsequent steps were carried out in the same manner as in Example 1 to obtain an ethylene polymer powder of Comparative Example 5. The microporous membrane of Comparative Example 5 was obtained by the same operation as in Example 1.

[Comparative Example 6]
The solid catalyst component [A] and triisobutylaluminum were added from the bottom of the polymerization vessel, and then the resulting polymerization slurry was poured into methanol and allowed to stand for a while to precipitate the ethylene polymer powder, followed by decantation of methanol. The ethylene polymer powder of Comparative Example 6 was obtained in the same manner as in Example 1 except that methanol was again poured and washed, and then methanol was removed by decantation. In addition, content of the solvent etc. with respect to the polymer after a decantation was 230%. The microporous membrane of Comparative Example 6 was obtained by the same operation as in Example 1.

[Comparative Example 7]
Hexane, ethylene, hydrogen, and catalyst were continuously supplied to a vessel type 300 L polymerization reactor equipped with a stirrer. The polymerization pressure was 0.8 MPa. The polymerization temperature was kept at 74 ° C. by jacket cooling. Hexane was fed from the bottom of the polymerizer at 40 L / hr. The solid catalyst component [C] was used as the catalyst. The solid catalyst component [C] was added at a rate of 1.6 g / hr from the middle between the liquid surface and the bottom of the polymerization vessel, and diethylaluminum monoethoxide was added at a rate of 0.05 mmol / hr between the liquid level and the bottom of the polymerization vessel. Added from the middle. The production rate of the ethylene polymer was 9.1 kg / hr. Hydrogen was continuously supplied by a pump so that the hydrogen concentration with respect to ethylene in the gas phase was 6 mol%. In addition, hydrogen was supplied from the catalyst introduction line in order to contact with the catalyst in advance, and ethylene was supplied from the bottom of the polymerization vessel. The catalytic activity was 5,700 g-PE / g-solid catalyst component [C]. The polymerization slurry was continuously drawn into a flash drum having a pressure of 0.05 MPa and a temperature of 70 ° C. so that the level of the polymerization reactor was kept constant, and unreacted ethylene and hydrogen were separated.

  Next, the polymerization slurry was continuously sent to a centrifuge so that the level of the polymerization reactor was kept constant, and the polymer and other solvents were separated. At that time, the content of the solvent or the like with respect to the polymer was 51%.

  The separated ethylene polymer powder was dried while blowing nitrogen at 85 ° C. In this drying step, the catalyst and the cocatalyst were deactivated by spraying steam on the polymerized powder. To the obtained ethylene polymer powder, 1500 ppm of calcium stearate (manufactured by Dainichi Chemical Co., Ltd., C60) was added and uniformly mixed using a Henschel mixer to obtain an ethylene polymer powder of Comparative Example 7. The microporous membrane of Comparative Example 7 was obtained by the same operation as in Example 1.

  The ethylene polymer of the present invention is excellent in strength and dimensional accuracy, and a film or a microporous membrane containing the ethylene polymer is excellent in strength and dimensional accuracy. Furthermore, since the ethylene polymer of the present invention is also excellent in heat resistance, it can be annealed at a high temperature in a short time, particularly when forming a microporous film or film, and a molded body having high strength can be obtained. And can be suitably used for microporous membranes and films, and thus has high industrial applicability.

Claims (10)

The viscosity average molecular weight (Mv) is 200,000 or more and 500,000 or less,
The molecular weight distribution (Mw / Mn) is 3.0 or more and 10.0 or less,
There are two or more elution peaks measured by cross-fractionation chromatography (hereinafter referred to as “CFC”) measured using o-dichlorobenzene as a solvent under the following conditions (1) to (3) :
Elution amount of the measured 103 ° C. in the CFC, Ri 10 mass% or more and 20% by mass or less of the total elution amount,
Integral elution amount measured by CFC from 96 ° C to less than 100 ° C is 55% by mass or less of the total elution amount
And
The integrated elution amount measured by CFC of 100 ° C or more and less than 104 ° C is 35% by mass or less of the total elution amount.
Above,
Ethylene polymer.
(1) Hold an o-dichlorobenzene solution of an ethylene polymer at 140 ° C. for 120 minutes.
(2) The temperature of the ethylene polymer o-dichlorobenzene solution is lowered to 40 ° C. at 0.5 ° C./min, and then held for 20 minutes.
(3) The temperature of the column is increased at a rate of 20 ° C./min by the temperature program shown in the following (a) to (e). Hold that temperature for 21 minutes at each temperature reached.
(A) The temperature is increased from 40 ° C. to 60 ° C. at intervals of 10 ° C.
(B) The temperature is raised from 60 ° C. to 75 ° C. at intervals of 5 ° C.
(C) The temperature is raised from 75 ° C. to 90 ° C. at intervals of 3 ° C.
(D) The temperature is increased from 90 ° C. to 110 ° C. at 1 ° C. intervals.
(E) The temperature is raised from 110 ° C. to 120 ° C. at intervals of 5 ° C.   The ethylene polymer according to claim 1, which is a homopolymer.   The ethylene polymer according to claim 1 or 2, which is linear. The ethylene polymer according to any one of claims 1 to 3, wherein a melting point measured by a differential scanning calorimeter (DSC) is 133 ° C or higher and 138 ° C or lower. The ethylene polymer according to any one of claims 1 to 4, wherein an integrated elution amount measured by CFC of 40 ° C or more and less than 96 ° C is 10% by mass or less of the total elution amount. The ethylene polymer according to any one of claims 1 to 5 , wherein the residual catalyst ash content is 50 ppm or less. The ethylene polymer according to any one of claims 1 to 6 , wherein a component having a molecular weight of 1,000,000 or more in terms of polystyrene is 10% by mass or less. A stretch-molded product comprising the ethylene polymer according to any one of claims 1 to 7 . A microporous membrane comprising the ethylene polymer according to any one of claims 1 to 7 . Ethylene polymer containing body, a battery separator according to any one of claims 1-7.