JP5767203B2 - Ethylene polymer, stretched molded body, microporous membrane, and battery separator - Google Patents

Description

  The present invention relates to an ethylene polymer, a stretched molded product, a microporous membrane, and a battery separator.

  Ethylene polymers are used in various applications such as sheets, films, microporous membranes, fibers, and molded products. In these applications, excellent mechanical strength is required. A microporous membrane containing an ethylene polymer functions as a separator that separates the positive electrode and negative electrode and allows only ions to pass through in battery applications, and shutdown to prevent the risk of battery reaction runaway due to high temperature inside the battery It is used as a member having both functions. In particular, the demand as a separator has been growing rapidly in recent years, and a microporous film made of an ethylene polymer is used as a separator that is an important member of 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 intensity | strength, and the high molecular weight polyethylene with a large molecular weight is mainly used (for example, refer patent document 2). However, high-density polyethylene having a large molecular weight is difficult to dissolve or melt and has low fluidity. Therefore, there is a problem that molding is difficult and stable production is not possible.

  In general, the production process of a microporous membrane or the like includes a process of dissolving an ethylene polymer in liquid paraffin and extruding. In addition, the production process of a film or the like includes a process of melting and extruding an ethylene polymer. In such cases, it is important to dissolve or melt completely and quickly to a uniform state. Dissolution or melting of the ethylene polymer is initiated by molecular motion of a component that is likely to undergo molecular motion even at a low temperature (hereinafter also referred to as “amorphous component”). However, polyethylene with a large molecular weight has few amorphous components and poor molecular mobility, so it takes time to dissolve or melt. Therefore, the unmelted product tends to remain in the melt. If the unmelted material remains, the filter of the extruder is clogged, and the film thickness of the microporous film or the film is not stable, or the unmelted material that has passed through the filter remains on the film.

  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.

JP 60-23594 A Japanese Patent Laid-Open No. 2010-74073 JP-A-2-21559

  Patent Document 3 discloses a method of blending an ethylene polymer having a viscosity average molecular weight (Mv) of 300,000 or less and an ultrahigh molecular weight ethylene polymer having a viscosity of 1,000,000 or more. In general, it is known that the ethylene polymer increases in the crystalline component as the molecular weight increases. The ultra-high molecular weight ethylene polymer is responsible for the strength and the low molecular weight ethylene polymer is responsible for the moldability. It is considered a thing.

  However, an ethylene polymer having a viscosity average molecular weight (Mv) of 300,000 or less is not preferable from the viewpoint of strength and has a problem because it is inferior in heat resistance.

  The present invention has been made in view of the above problems, gives a molded article having excellent mechanical strength, exhibits excellent melting or melting properties, and has excellent molding processability, as well as stretching, It aims at providing a molded object, a microporous film, and a battery separator.

  Therefore, as a result of intensive studies to solve the above problems, the present inventors have determined a predetermined elution at 103 ° C. measured by a predetermined viscosity average molecular weight, a predetermined molecular weight distribution, and cross fractionation chromatography (CFC). It has been found that the above-mentioned problems can be solved by using an ethylene polymer having an amount, and the present invention has been completed.

That is, the present invention is as follows.
[1]
The viscosity average molecular weight (Mv) is 400,000 or more and 700,000 or less,
The molecular weight distribution (Mw / Mn) is 8.0 or more and 15.0 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 0.1% by mass or more and less than 10% by mass of the total elution amount,
The integral elution amount measured by CFC of 96 ° C. or more and less than 100 ° C. is 55% by mass or more of the total elution amount,
The integrated elution amount of 100 ° C. or more and less than 104 ° C. measured by CFC is 35% by mass or less of the total elution amount.
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 claim 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]
In the elution amount measured at CFC of 101 ° C. or higher, the weight average molecular weight (Mw) at the temperature at which the maximum elution amount is obtained is 500,000 or more. Ethylene polymer.
[7]
The ethylene polymer according to any one of [1] to [6], wherein a component having a molecular weight of 1,000,000 or more in terms of polyethylene is 10% by mass or more.
[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].

  According to the present invention, an ethylene polymer that gives a molded article having excellent mechanical strength, exhibits excellent solubility or meltability, and has excellent molding processability, and a stretch-molded article, a microporous membrane, and a battery including the same are provided. A separator can be realized.

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 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 400,000 or more and 700,000 or less, a molecular weight distribution (Mw / Mn) of 8.0 or more and 15.0 or less, and cross fractionation chromatography. The amount of elution at 103 ° C. measured in (hereinafter also referred to as “CFC”) is 0.1% by mass or more and less than 10% by mass. 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 400,000 or more and 700,000 or less, preferably 420,000 or more and 680,000 or less, more preferably 450,000 or more and 650,000. It is as follows. The viscosity average molecular weight (Mv) of the ethylene polymer can be adjusted by appropriately adjusting the polymerization conditions described later. Specifically, the viscosity average molecular weight (Mv) can be adjusted by making hydrogen exist as a chain transfer agent in the polymerization system or changing the polymerization temperature.

  When the viscosity average molecular weight (Mv) is 400,000 or more, a molded body such as a microporous film containing the ethylene polymer of the present embodiment has sufficient mechanical strength. On the other hand, when the viscosity average molecular weight (Mv) is 700,000 or less, the ethylene polymer of this embodiment is excellent in melt fluidity, solubility in a solvent, stretchability, and the like, and excellent in moldability. Therefore, when a film or a film is formed using the ethylene polymer of the present embodiment, uneven thickness hardly occurs.

The viscosity average molecular weight (Mv) of the ethylene polymer of this embodiment is prepared by preparing solutions in which ethylene polymer is dissolved at different concentrations in decalin, measuring the solution viscosity at 135 ° C. of the solution, and measuring the measured solution viscosity. The reduced viscosity calculated from the above is extrapolated to a concentration of 0 to determine the intrinsic viscosity, and can be calculated from the obtained intrinsic viscosity [η] (dL / g) according to the following formula A. 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 8.0 or more and 15.0 or less, preferably 9.0 or more and 14.8 or less, and more preferably 10.0 or more and 14.4. 5 or less. The molecular weight distribution (Mw / Mn) of the ethylene polymer of the present embodiment can be adjusted by appropriately adjusting the polymerization conditions described later. In addition, the molecular weight distribution of the ethylene polymer should be made small (15.0 or less) by using the catalyst of this embodiment or keeping the conditions (hydrogen concentration, temperature, ethylene pressure, etc.) in the polymerization system constant. Can do. On the other hand, as a method for increasing the molecular weight distribution of the ethylene polymer, the conditions during the polymerization are changed (for example, the concentration of hydrogen as a chain transfer agent is changed during the polymerization), or an ethylene polymer having a different molecular weight is used. The method of mixing etc. is mentioned.

  When the molecular weight distribution (Mw / Mn) is 8.0 or more, the ethylene polymer of this embodiment is excellent in melt fluidity, solubility in a solvent, stretchability, and the like, and excellent in moldability. In addition, since the molecular weight distribution (Mw / Mn) is 15.0 or less, low molecular weight components eluted at a low temperature can be reduced, and a molded body such as a film or a film containing the ethylene polymer of the present embodiment can be obtained. , Having sufficient strength.

  The number average molecular weight (Mn), weight average molecular weight (Mw), and molecular weight distribution (Mw / Mn) of the ethylene polymer of this embodiment are determined by gel permeation chromatography (hereinafter, “ It is also called “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 0.1% by mass or more and less than 10% by mass, preferably 0.3% by mass or more and less than 9.5% by mass. More preferably, it is 0.5 mass% or more and less than 9.0 mass%. When the elution amount at 103 ° C. is 0.1% by mass or more and less than 10% by mass of the total elution amount, even an ethylene polymer having a high molecular weight can be easily melted and melted and has excellent moldability. . Therefore, a molded body such as a microporous film containing the ethylene polymer of this embodiment has excellent mechanical strength and excellent dimensional accuracy.

  Here, “cross fractionation chromatography (CFC)” is an apparatus 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. This is an apparatus capable of analyzing the mutual relationship between the composition distribution and the molecular weight distribution by directly connecting the TREF part and the GPC part. Note that the measurement at the TREF unit may be referred to as the measurement at the CFC.

  The measurement by the TREF section can be 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 increased continuously or 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 elution 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. 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 is increased at 1 ° C intervals, and the temperature is increased from 110 ° C to 120 ° C at 5 ° C intervals. 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. Then, an elution temperature-elution amount curve (see 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 elution integrals are 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 0.1% by mass or more and less than 10% by mass of the total elution amount, batch polymerization to be described later, jacket cooling and condenser cooling are used in combination, and the polymerization temperature changes. Or reducing the slurry concentration to 20% by mass or less.

  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 of a molded product such as a film containing a polyethylene polymer or a microporous membrane tends to be more excellent. 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 possible to appropriately adjust the same means as the above-described adjusting means for the elution amount of 103 ° C.

  It is preferable that two or more elution peaks measured by CFC of the ethylene polymer of this embodiment exist. In order to improve the moldability while maintaining the molecular weight that expresses sufficient mechanical strength, the low temperature side elution peak derived from the amorphous component (elution amount less than 101 ° C) and the high temperature side elution derived from the crystalline component It is preferable that there are two peaks (elution amount of 101 ° C. or higher), or two or more elution peaks.

  Moreover, the integral elution amount of 96 ° C. or more and less than 100 ° C., which is a low temperature side elution peak, is 55% by mass or more of the total elution amount, and the integral elution amount of 100 ° C. or more and less than 104 ° C., which is a high temperature side elution peak. Preferably, the integrated elution amount from 96 ° C. to less than 100 ° C. is 56% by mass or more, and the integrated elution amount from 100 ° C. to less than 104 ° C. is 34% by mass or less. More preferably, the integrated elution amount from 96 ° C. to less than 100 ° C. is 57% by mass or more, and the integrated elution amount from 100 ° C. to less than 104 ° C. is 33% by mass or less. The integral elution amount of 96 ° C. or more and less than 100 ° C. is preferably 70% by mass or less, more preferably 69% by mass or less, and further preferably 68% by mass or less. The integrated elution amount at 100 ° C. or more and less than 104 ° C. is preferably 20% by mass or more, more preferably 21% by mass or more, and further preferably 22% by mass or more. An ethylene polymer which gives a molded article with more excellent mechanical strength and has excellent molding processability by having an integrated elution amount of 96 ° C. or more and less than 100 ° C. and an integrated elution amount of 100 ° C. or more and less than 104 ° C. And a stretched molded body, a microporous membrane, and a battery separator including the same. 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. For example, the means may be adjusted appropriately.

  In the elution amount measured by CFC of the ethylene polymer of the present embodiment, the weight average molecular weight (Mw) at the temperature at which the maximum elution amount (high temperature side elution peak) is obtained is 500,000 or more. Preferably, it is 520,000 or more, more preferably 540,000 or more. The weight average molecular weight (Mw) is preferably 1,000,000 or less, more preferably 980,000 or less, and further preferably 960,000 or less. When the weight average molecular weight (Mw) at the temperature at which the maximum elution peak is the maximum elution amount is 500,000 or more, the mechanical strength tends to be superior. Furthermore, the microporous membrane tends to retain its shape as a membrane even after it becomes hot and melts to close the microporous. That is, it is preferable because the film has excellent shutdown characteristics.

  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 mechanical strength, heat resistance, and heat shrinkage. When the ethylene polymer contains a copolymer of ethylene and another comonomer, it is preferable that the comonomer is inserted into the copolymer as long as the mechanical strength and the heat resistance are not deteriorated. 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 90% or more and less than 100%. More preferably it is. 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 heat resistance necessary for the microporous membrane can be exhibited, and the strength of the membrane tends to increase. 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.

The density of the ethylene polymer of the present embodiment 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, and further preferably 950 kg / m ³ or more. 980 kg / cm ³ or less. When the density is in the above range, the mechanical strength of a molded article such as a film containing the ethylene polymer of the present embodiment or a microporous film tends to be superior.

  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 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 component having a molecular weight of 1,000,000 or more in terms of polyethylene of the ethylene polymer of this embodiment is preferably 5% or more, more preferably 7% by mass or more, and further preferably 10% by mass or more. Moreover, it is preferable that the component of molecular weight 1,000,000 or more in polyethylene conversion is 30 mass% or less, More preferably, it is 28 mass% or less, More preferably, it is 26 mass% or less. 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, the mechanical strength of a molded article such as a film containing the ethylene polymer of this embodiment or a microporous film tends to be more excellent. . 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 as a chain transfer agent in the polymerization system or changing the polymerization temperature.

[Catalyst component]
The catalyst component used for the production of the ethylene polymer of this embodiment is not particularly limited, and 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 particularly 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 more 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. To a carrier (C-3) prepared by reacting an organomagnesium compound (C-1) soluble in an inert hydrocarbon solvent and a chlorinating agent (C-2) represented by formula 4, Olefin produced by supporting an organomagnesium compound (C-4) soluble in an inert hydrocarbon solvent represented by formula 5 and a titanium compound (C-5) represented by formula 6 Polymerization catalysts are preferred.
(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 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 6 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, die Aluminum halide compounds such as tilaluminum 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 the present embodiment is usually preferably from 30 ° C. to 100 ° C., more preferably from 35 ° C. to 95 ° C., and further preferably from 40 ° C. to 90 ° C. When the polymerization temperature is 30 ° C. or higher, industrially efficient production is possible. On the other hand, when the polymerization temperature is 100 ° C. or lower, stable operation can be continuously performed.

  From the viewpoint of suppressing a local high temperature state, the polymerization temperature is preferably controlled by using a jacket and a condenser for cooling the vaporized solvent or the like. By preventing the local high temperature state, the ethylene polymer is suppressed from adhering to the polymerization vessel, and tends to enable stable production. Moreover, it exists in the tendency which can prevent that the molecular weight of the attached ethylene polymer becomes large too much and the ultrahigh molecular weight body becomes an unmelted material. Further, conversely, the molecular weight tends to be too small and the mechanical strength of the film or film tends to be prevented from being lowered.

  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 batch manner. If it is a batch type, it becomes easy to adjust the molecular weight distribution, molecular weight composition, etc. of this embodiment as appropriate, and the particle size distribution of the produced ethylene polymer powder tends to be uniform. Therefore, in order to obtain the ethylene polymer of this embodiment, a batch type 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, hydrogen can be added into the system sequentially. By changing the hydrogen concentration during the polymerization reaction, the molecular weight distribution, the molecular weight composition, and the like can be appropriately adjusted.

  The slurry concentration in the ethylene polymer production method of the present embodiment is preferably 20% by mass or less, more preferably 18% by mass, from the viewpoint of controlling the polymerization temperature and suppressing the production of ethylene polymer powder having a large particle size. % Or less, more preferably 15% by mass or less. The “slurry concentration” refers to the ratio of the ethylene polymer powder to the total 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 drying temperature in the method for producing a heat-resistant ethylene polymer of this embodiment is usually preferably 50 ° C. or higher and 150 ° C. or lower, more preferably 50 ° C. or higher and 140 ° C. or lower, and further preferably 50 ° C. or higher and 130 ° C. or lower. When the drying temperature is 50 ° C. or higher, efficient drying is possible. On the other hand, when the drying temperature is 150 ° C. or lower, it is possible to dry in a state where decomposition and crosslinking of the ethylene polymer are suppressed.

  The powder size in the method for producing an ethylene polymer of the present embodiment is preferably such that the content of particles having a particle diameter of 420 μm or more is 2% by mass or less from the viewpoint of suppressing gels such as films and membranes. More preferably, it is 1.5 mass% or less, More preferably, it is 1 mass% or less. The said content rate can also be adjusted by removing large particle size powder with a sieve.

  As described above, the ethylene polymer of the present embodiment is a material that can achieve both mechanical strength and moldability when formed into a film or film, and suppresses the generation of low molecular weight components and ultrahigh molecular weight materials. is important. In the present embodiment, in addition to the above items, other known production methods useful for producing an ethylene polymer can be included.

[Additive]
Furthermore, you may add additives, such as a neutralizing agent, antioxidant, and a light-resistant stabilizer, to the ethylene polymer which concerns on this embodiment.

  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. The content of the neutralizing agent is not particularly limited, but is preferably 5,000 ppm or less, more preferably 4,000 ppm or less, and still more preferably 3,000 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, It is preferable that it is 5,000 ppm or less, 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 preferable that it is 5,000 ppm or less, More preferably, it is 4,000 ppm or less, More preferably, it is 3,000 ppm or less.

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

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. Can also be used.
Moreover, even if the ethylene polymer of this embodiment is a powder form or a pellet form, it can be used conveniently.

[Usage]
The ethylene polymer obtained as described above can have high heat resistance, is excellent in molding processability, and can be processed by various processing methods. For example, when the ethylene polymer of the present embodiment is dissolved in a solvent and molded, a molded body free from unmelted gel can be obtained. In addition, even when the powder is kneaded as it is in an extruder without being dissolved in a solvent, it is possible to suppress a decrease in melt fluidity resulting from the molecular weight being too high, and a state in which melt kneading cannot be performed (unmelted material remains, resulting in uneven thickness) Or the load on the extruder becomes too large).

  Moreover, the molded object containing an ethylene polymer can be applied to various uses. In particular, the ethylene polymer is suitable for a stretched molded body that is stretched and processed. For example, a molded body containing an ethylene polymer is suitable as a (secondary) battery separator, in particular, a lithium ion secondary battery separator, a high-strength fiber, a microporous membrane, or gel spinning. As a method for producing a microporous membrane, specifically, a wet method using a solvent and a processing method through extrusion, stretching, extraction, and drying in an extruder equipped with a T die can be mentioned. 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. Furthermore, as a method for producing high-strength fibers, in a wet method using a solvent, in an extruder equipped with a circular die, a gel is obtained, and a yarn is obtained by a processing method that undergoes stretching, extraction, and drying, The processing method which extends | stretches this further is mentioned. Such high-strength fibers can be used for fishing lines, blade-proof gloves, marine ropes, bulletproof vests, armored vehicle bulletproof covers, fishnets, sports equipment, sutures, and the like.

  In addition, by taking advantage of the characteristics of high molecular weight ethylene polymer, such as wear resistance, high slidability, high strength, and high impact properties, gears can be formed by solid molding such as extrusion molding, press molding and cutting. Can be used for lining materials for heavy equipment such as skis and ski soles, trucks and shovel cars Can be mentioned. Moreover, in sintering molding etc., it can use for 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.

[Measurement method and conditions]
(1) Viscosity average molecular weight (Mv)
About the viscosity average molecular weight of the ethylene polymer manufactured by the Example and the comparative example, it calculated | required by the method shown below. 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 distribution (Mw / Mn)
For a sample solution prepared by mixing 20 mg of the ethylene polymer produced in Examples and Comparative Examples and 15 mL of o-dichlorobenzene and stirring at 150 ° C. for 1 hour, gel permeation chromatography (GPC) was performed under the following conditions. ) Was measured. 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) Content of components having a molecular weight of 1,000,000 or more in terms of polyethylene From the GPC chart obtained in (2), the content of components having a molecular weight of 1,000,000 or more in terms of polyethylene was obtained.

(4) 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 an ethylene polymer sample produced in Examples and Comparative Examples 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.).

(5) CFC elution amount (TREF elution amount)
For the ethylene polymers produced in the examples and comparative examples, the elution temperature-elution amount curve by temperature rising elution fractionation (TREF) was measured as follows, the elution amount at each temperature, the elution integrated amount, and the high temperature side elution The weight average molecular weight (Mw) at the temperature at which the peak peak was eluted was 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, the 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 at each temperature are measured. The amount was determined. 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.d x 150mm)
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 (μm)
The film thickness of the microporous film formed in Examples and Comparative Examples was measured at a room temperature of 23 ° C. using a micro thickness gauge (type KBM (trademark)) manufactured by Toyo Seiki.

(7) Uneven thickness characteristics The uneven thickness characteristics of the microporous membranes formed in the examples and comparative examples were measured using a contact-type continuous thickness measuring device (ANRITSU K310D manufactured by Anritsu Electric Co., Ltd.) in the width direction of the film. Measurement was performed, and the height of the peak relative to the baseline was read at 1 μm intervals on the chart and evaluated based on the read value. In addition, when two or more peaks were expressed, it was set as the total value of each peak.
(Evaluation criteria)
◎ (very good) ... less than 0.1 µm ○ (no problem) ... 0.1 µm or more, less than 0.3 µm × (bad) ... 0.3 µm or more

(8) Average number of defects The defects of 0.5 mm ² or more derived from the unmelted polymer or the like in the microporous film formed in the examples and comparative examples were observed visually. The entire surface of the sample of 50 m ² was observed, and the average number of defects per 1 m ² was determined.

(9) TD direction tensile strength (MPa), TD direction tensile elongation (%)
TD direction (vertical direction) tensile strength (MPa) and TD direction tensile elongation (%) are based on JIS K7127, using a tensile tester manufactured by Shimadzu Corporation, Autograph AG-A type (trademark) Measurement was performed on TD samples (shape: width 10 mm × length 100 mm) of polyethylene polymers produced in Examples and Comparative Examples. In addition, the TD sample had a chuck spacing of 50 mm and a cellophane tape (manufactured by Nitto Denko Packaging System Co., Ltd., trade name: N.29) on one side of both ends (25 mm each) of the sample. Furthermore, in order to prevent sample slippage during the test, 1 mm-thick fluororubber was affixed inside the chuck of the tensile tester.

  The tensile elongation (%) in the TD direction was obtained by dividing the amount of elongation (mm) until rupture by the distance between chucks (50 mm) and multiplying by 100.

  The TD direction tensile strength (MPa) was determined by dividing the strength at break by the sample cross-sectional area before the test. The TD tensile strength (MPa) and TD tensile elongation (%) were measured at a temperature of 23 ± 2 ° C., a chuck pressure of 0.30 MPa, and a tensile speed of 200 mm / min.

[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 a 1 mol / L titanium tetrachloride hexane solution and 800 mL of a hexane solution of an 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, 1,600 mL of the supernatant was removed, and the solid catalyst component [A] was prepared by washing 3 times with 1,600 mL of hexane. The amount of titanium contained in 1 g of this solid catalyst component [A] was 2.95 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 2 hours, 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) carrier), magnesium contained per 1 g of the solid was 8.02 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 organic magnesium compound represented by the formula AlMg ₅ (C ₄ H ₉ ) ₁₁ (OSiH) ₂ was added simultaneously over 15 minutes. After the addition, the reaction was continued at 10 ° C. for 1 hour. After completion of the reaction, 1,100 mL of the supernatant was removed and washed once with 1,100 mL of hexane to prepare a solid catalyst component [B]. The amount of titanium contained in 1 g of this solid catalyst component [B] was 0.70 mmol.

[Example 1]
(Ethylene polymer polymerization process)
Supply ethylene and hydrogen (12-18 mol% with respect to 100 mol% of total ethylene and hydrogen) to a vessel type 30 L polymerization reactor equipped with a stirrer containing hexane 14 L (total amount) while intermittently changing the hydrogen concentration. The polymerization pressure was 0.5 MPa. The polymerization reaction was started by adding 0.025 mmol of triisobutylaluminum as a cocatalyst and then adding 0.02 g of the solid catalyst component [A]. Even during the polymerization reaction, ethylene was fed at a constant rate of 0.5 L / min. The polymerization temperature was maintained from 82 ° C. (polymerization start temperature) to 85 ° C. (maximum temperature reached) by jacket cooling and condenser cooling.

  After 3 hours, the polymerization temperature was lowered to 60 ° C., and the reactor was depressurized to remove unreacted ethylene and hydrogen. After replacing the inside of the polymerization system with nitrogen, the polymerization slurry was poured into methanol to completely stop the polymerization reaction. The slurry concentration was 10.0% by mass, and the catalytic activity was 50,000 g-PE / g-solid catalyst component [A].

  Next, the polymerization slurry was sent to a filtration tank with a filter to separate the polymer and the solvent. Then, the ethylene polymer of Example 1 was obtained by heat-drying at 85 degreeC for 12 hours with a hot air dryer.

  When the physical properties of the ethylene polymer of Example 1 were measured, the viscosity average molecular weight (Mv) was 442,000 g / mol, the molecular weight distribution (Mw / Mn) was 12.2, and the elution amount at 103 ° C. measured by CFC was 6.0% by mass of the total elution amount, 9.5% by mass of the total elution amount from 40 ° C. to less than 96 ° C., and 56.8% by mass of the total elution amount from 96 ° C. to less than 100 ° C. The integrated elution amount from 100 ° C. to less than 104 ° C. was 32.5% by mass of the total elution amount. Table 1 shows the characteristics of the ethylene polymer obtained by the above operation. FIG. 2 shows an elution temperature-elution amount curve obtained by CFC measurement.

(Method for producing microporous membrane)
To 100 parts by mass of the powdery ethylene polymer, 0.3 part by mass of pentaerythrityl-tetrakis- [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] is added as an antioxidant. Then, an ethylene polymer composition was obtained by dry blending using a tumbler blender. The obtained ethylene polymer composition was substituted with nitrogen, and then charged into a twin-screw extruder through a feeder under a nitrogen atmosphere. Furthermore, 65 parts of liquid paraffin (P-350 (trademark) manufactured by Matsumura Oil Co., Ltd.) was injected into the extruder by side feed and kneaded at a set temperature of 200 ° C. and a screw rotation speed of 240 rpm. The melt-kneaded material is passed through a Gnois disk filter type continuous screen exchanger equipped with a screen equivalent to 350 mesh, and then discharged from a T-die and cast with a roll to obtain a gel having a thickness of 1,250 μm. A shaped sheet was formed.

  The gel sheet was stretched at 124 ° C. using a simultaneous biaxial stretching machine at an MD magnification of 7.0 times and a TD magnification of 6.4 times, and the stretched film was immersed in methyl ethyl ketone to extract and remove liquid paraffin. And then dried. Next, the stretched film was guided to a TD tenter and heat-fixed to obtain a microporous film of Example 1. The stretching temperature during heat setting was 128 ° C., the magnification was 2.0 times, the temperature during subsequent relaxation was 133 ° C., and the relaxation rate was 0.80. Table 1 shows the physical properties of the obtained microporous membrane.

[Example 2]
In the polymerization step, the same procedure as in Example 1 was performed except that the solid catalyst component [B] was used instead of the solid catalyst component [A], to obtain an ethylene polymer of Example 2. . The microporous membrane was obtained by the same operation as in Example 1.

[Example 3]
In the polymerization step, an ethylene polymer of Example 3 was obtained by performing the same operation as in Example 1 except that the hydrogen concentration was 6 to 13 mol%. The microporous membrane was obtained by the same operation as in Example 1.

[Example 4]
In the polymerization step, the same operation as in Example 1 was performed, except that the solid catalyst component [B] was used instead of the solid catalyst component [A], and the hydrogen concentration was changed to 6 to 13 mol%. The ethylene polymer of Example 4 was obtained. The microporous membrane was obtained by the same operation as in Example 1.

[Comparative Example 1]
In the polymerization step, the same operation as in Example 1 was performed except that the hydrogen concentration was changed to 17 to 23 mol%, whereby an ethylene polymer of Comparative Example 1 was obtained. The microporous membrane was obtained by the same operation as in Example 1.

[Comparative Example 2]
In the polymerization step, the same operation as in Example 1 was performed except that the hydrogen concentration was set to 2 to 8 mol%, whereby an ethylene polymer of Comparative Example 2 was obtained. The microporous membrane was obtained by the same operation as in Example 1.

[Comparative Example 3]
In the polymerization step, the polymerization temperature is kept from 72 ° C. (polymerization start temperature) to 76 ° C. (maximum temperature reached), and the polymerization pressure is always increased from 0.48 MPa to 0.50 MPa while supplying ethylene and hydrogen (97/3 mol%). Except having been kept, the same operation as in Example 1 was performed to obtain an ethylene polymer of Comparative Example 3. The microporous membrane was obtained by the same operation as in Example 1.

[Comparative Example 4]
The same procedure as in Example 1 was performed except that the hydrogen concentration was changed to 9 to 21 mol% in the polymerization step, and an ethylene polymer of Comparative Example 4 was obtained. The microporous membrane was obtained by the same operation as in Example 1.

[Comparative Example 5]
In the polymerization step, an ethylene polymer of Comparative Example 5 was prepared in the same manner as in Example 1 except that instead of ethylene, a mixed gas of 96/4 mol% of ethylene and 1-butene was used and the hydrogen concentration was changed to 14 to 20 mol%. I got a powder. The microporous membrane was obtained by the same operation as in Example 1.

[Comparative Example 6]
Hexane, ethylene, hydrogen, and catalyst were continuously fed into 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 to the polymerization vessel at a rate of 0.2 g / hr, and triisobutylaluminum was added at a rate of 10 mmol / hr. The production rate of the ethylene polymer was 9 kg / hr. Hydrogen was continuously supplied by a pump so that the hydrogen concentration with respect to ethylene in the gas phase was 7 mol%. The slurry concentration was 30.0% by mass, and the catalyst activity was 65,000 g-PE / g-solid catalyst component [A]. The polymerization slurry is 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 is kept constant, unreacted ethylene and hydrogen are separated, and the polymerization slurry is poured into methanol. The polymerization reaction was completely stopped. 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. Then, the ethylene polymer of the comparative example 6 was obtained by heat-drying at 85 degreeC for 12 hours with a hot air dryer. Table 1 shows the characteristics of the ethylene polymer obtained by the above operation. The microporous membrane was obtained by the same operation as in Example 1.

  From the above results, the ethylene polymer of the present invention gives a molded article having excellent mechanical strength, and is excellent in solubility or meltability. Therefore, it is molded with less melted gel (defects) and uneven thickness in the molded article. It turns out that it will be excellent in workability. Further, in the comparative example, the average number of defects is high, the poorly soluble ethylene polymer powder remains in the film as it remains, and when the film is stretched, defects due to undissolved residue occur. However, it can be seen that the electrolyte membranes of the examples have a low average number of defects and good solubility.

  The ethylene polymer of the present invention gives a molded product having excellent mechanical strength, and the stretched molded product, microporous membrane, and battery separator containing the ethylene polymer of the present invention are excellent in strength and dimensional accuracy. Furthermore, since the ethylene polymer of the present invention is excellent in molding processability, it is possible to obtain a molded body free from gels derived from unmelted materials, and can be suitably used for microporous membranes and films. Have potential.

Claims (10)

The viscosity average molecular weight (Mv) is 400,000 or more and 700,000 or less,
The molecular weight distribution (Mw / Mn) is 8.0 or more and 15.0 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 volume of 103 ° C. as measured by CFC is state, and are less than 0.1% by weight to 10% by weight of the total elution amount,
The integral elution amount measured by CFC of 96 ° C. or more and less than 100 ° C. is 55% by mass or more of the total elution amount,
The integrated elution amount of 100 ° C. or more and less than 104 ° C. measured by CFC is 35% by mass or less of the total elution amount.
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 weight according to any one of claims 1 to 5 , wherein a weight average molecular weight (Mw) at a temperature at which the maximum elution amount is obtained at an elution amount of 101 ° C or higher measured by CFC is 500,000 or more. Coalescence. 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 polyethylene is 10% by mass or more. 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, separators for a battery according to any one of claims 1-7.