JP2007284664A - Ultra high molecular weight ethylene-based copolymer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultra high molecular weight ethylene-based copolymer whose transparency is improved by using a little amount of an α-olefin. <P>SOLUTION: The ultra high molecular weight ethylene-based copolymer is obtained by copolymerizing a monomer mixture of ethylene and the α-olefin whose carbon atom number is at least 3 and not more than 8, and has a viscosity average molecular weight of at least one million, and a content of a polymerization unit originated in α-olefin is at least 0.01 mol% and less than 1 mol% based on sum total of polymerization unit originated in ethylene and α-olefin whose carbon number is at least 3 and not more than 8, and relation between content �x(mol%)} of a polymer unit originated in the α-olefin and haze �y(%)} as an index of transparency of a polymer satisfies numerical formula (1); -107.5x+87≤y≤-43x+89 or numerical formula (2); 44≤y≤71.8. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an ultrahigh molecular weight ethylene copolymer. More specifically, a copolymer of a monomer mixture containing ethylene and an α-olefin having 3 to 8 carbon atoms, having a viscosity average molecular weight (Mv) of 1 million or more, relatively low density and transparency. The present invention relates to an ultra-high molecular weight ethylene copolymer excellent in.

  Conventionally, ultrahigh molecular weight olefins, particularly ultrahigh molecular weight polyethylene, are superior in impact resistance, wear resistance, slidability, and chemical resistance compared to general-purpose polyethylene, and can be used as sliding parts. Furthermore, since it has excellent long-term characteristics, it is also used for molded products such as pipes. However, ordinary high molecular weight polyethylene has high crystallinity and is white and opaque, and even if the pipe thickness is thin, it is inferior in transparency, and there is a problem that the distribution in the pipe cannot be seen. It was sought after.

  In order to improve the transparency of the ultrahigh molecular weight polyethylene, Patent Document 1 proposes an ultrahigh molecular weight ethylene copolymer obtained from ethylene and another α-olefin. Patent Document 1 discloses an ultra-high molecular weight polyethylene copolymer that exhibits high impact and high transparency while maintaining high strength, high elasticity, and abrasion resistance by copolymerization of ethylene and α-olefin. Has been. However, in this technique, it was necessary to introduce a large amount of α-olefin into the main chain in order to improve transparency.

Further, in the technique of Patent Document 1, since it is necessary to introduce a large amount of α-olefin into the main chain, the molecular weight of the produced copolymer tends to be remarkably lowered, and in order to avoid this, There is also a problem that the polymerization temperature needs to be lowered, and thus productivity is remarkably lowered. Further, Patent Document 1 does not describe the correlation between α-olefin content and haze, which is an index of transparency.
Japanese Patent Publication No. 5-86803

  An object of the present invention is to provide an ultrahigh molecular weight ethylene copolymer having improved transparency with a small amount of α-olefin.

  As a result of intensive studies to solve the above problems, the present inventors have determined that the main chain has a molecular weight and density, and further that the relationship between the α-olefin content in the copolymer and haze falls within a specific range. By introducing a small amount of α-olefin, a technology has been developed that can provide an ultra-high molecular weight ethylene copolymer having excellent transparency and high molecular weight while maintaining high productivity.

That is, the present invention is as follows.
[1] Ultra high molecular weight ethylene copolymer having a viscosity average molecular weight (Mv) of 1 million or more obtained by copolymerizing a monomer mixture containing ethylene and an α-olefin having 3 to 8 carbon atoms Coalesce,
(1) The content of polymerized units derived from α-olefin is 0.01 mol% or more and less than 1 mol% based on the total number of polymerized units derived from ethylene and α-olefin having 3 to 8 carbon atoms. Yes,
(2) Content of polymer units derived from α-olefin {x (mol%)} and copolymer content based on total polymerized units derived from ethylene and α-olefin having 3 to 8 carbon atoms When x is in the range of 0.01 mol% or more and less than 0.4 mol%, x is 0.4 mol% or more when the relationship with the haze {y (%)} which is an index of transparency is in the range of 0.01 mol% or more and less than 0.4 mol%. An ultra high molecular weight ethylene copolymer characterized by satisfying the following mathematical formula (2) in a range of less than 1.0 mol%.
−107.5x + 87 ≦ y ≦ −43x + 89 Expression (1)
44 ≦ y ≦ 71.8... Formula (2)
[2] The relationship between x and y satisfies the following formula (3) when x is in the range of 0.4 mol% or more and less than 1.0 mol%, Molecular weight ethylene copolymer.
44 ≦ y ≦ −43x + 89 Expression (3)
[3] A carrier prepared by reacting an organomagnesium compound soluble in an inert hydrocarbon solvent represented by the following general formula (1) with a chlorinating agent represented by the following general formula (2) (A -1) A solid catalyst produced by supporting a titanium compound (A-2) represented by the following general formula (3) and an organometallic compound (A-3) represented by the following general formula (4) Manufactured using an olefin polymerization catalyst comprising component [A] and an organomagnesium compound represented by the following general formula (5) or component [B] which is an organoaluminum compound represented by the following general formula (6) The ultrahigh molecular weight ethylene copolymer according to any one of [1] or [2] above, wherein
(M ¹ ) α (Mg) β (R ¹ ) _a (R ² ) _b (OR ³ ) _c Formula (1)
(In the formula, M ¹ is a metal atom other than magnesium belonging to the group consisting of Group 1, Group 2, Group 12 and Group 13 of the Periodic Table, and R ¹ , R ² and R ³ are each independently And α, β, a, b and c are real numbers satisfying the following relationship: 0 ≦ α, 0 <β, 0 ≦ a, 0 ≦ b , 0 ≦ c, 0 <a + b, 0 ≦ c / (α + β) ≦ 2, kα + 2β = a + b + c ( where, k is the valence of M ¹⁾⁾
H _d SiCl _e R ⁴ _{(4- (d + e))} (2)
(Wherein R ⁴ is a hydrocarbon group having 1 to 12 carbon atoms, and d and e are real numbers satisfying the following relationship: 0 <d, 0 <e, 0 <d + e ≦ 4)
Ti (OR ⁵ ) _f X ¹ _(4-f) Formula (3)
(In the formula, f is a real number of 0 or more and 4 or less, R ⁵ is a hydrocarbon group of 1 to 20 carbon atoms, and X ¹ is a halogen atom.)
(M ² ) γ (Mg) ε (R ⁶ ) _h (R ⁷ ) _i Y _j Expression (4)
(In the formula, M ² is a metal atom belonging to the group consisting of Group 1, Group 2, Group 12 and Group 13 of the periodic table, and R ⁶ and R ⁷ each independently represent 2 carbon atoms. 20 or less hydrocarbon group, Y is alkoxy, siloxy, allyloxy, amino, amide, —N═C—R ⁸ R ⁹ , —SR ¹⁰ (where R ⁸ , R ⁹ and R ¹⁰ are carbon atoms) Represents a hydrocarbon group of 2 or more and 20 or less), β-keto acid residues, and γ, ε, h, i and j are real numbers satisfying the following relationship: 0 ≦ γ, 0 <ε, 0 ≦ h, 0 ≦ i, 0 < h + i, 0 ≦ j / (γ + ε) ≦ 2, nγ + 2ε = h + i + j ( where, n represents the valence of M ²⁾⁾
(M ³ ) κ (Mg) λ (R ¹¹ ) _p (R ¹² ) _q (OR ¹³ ) _r Expression (5)
(In the formula, M ³ is a metal atom belonging to the group consisting of Group 1, Group 2, Group 12 and Group 13 of the Periodic Table; R ¹¹ , R ¹² and R ¹³ are each independently It is a hydrocarbon group having 2 to 20 carbon atoms, and κ, λ, p, q and r are numbers satisfying the following relationship: 0 ≦ κ, 0 <λ, 0 ≦ p, 0 ≦ q, 0 ≦ r, 0 <p + q, 0 ≦ r / (κ + λ) ≦ 2, kκ + 2λ = p + q + r (where k is the valence of M ³ ))
AlR ¹⁴ _s X ² _3-s (6)
(In the formula, each R ¹⁴ independently represents a linear, branched or cyclic alkyl group having 1 to 12 carbon atoms or an aryl group having 6 to 20 carbon atoms, and X ² is each independently And a halide, a hydride, or an alkoxide group having 1 to 10 carbon atoms, and s is a real number having 1 to 3 carbon atoms.)

  According to the present invention, an ultrahigh molecular weight ethylene copolymer having improved transparency with a small amount of α-olefin can be provided.

The present invention will be specifically described below.
The ultra high molecular weight ethylene copolymer provided by the present invention is an ultra high molecular weight ethylene copolymer derived from ethylene and an α-olefin having 3 to 8 carbon atoms. In the present invention, the mole fraction of polymer units derived from α-olefins relative to polymer units derived from ethylene and α-olefins having 3 to 8 carbon atoms contained in the ultrahigh molecular weight ethylene copolymer. The rate is also referred to as the olefin content.

In the present invention, the α-olefin having 3 to 8 carbon atoms is not particularly limited, and examples thereof include those represented by the following general formula (A).
CH ₂ = CR ¹⁵ R ¹⁶ ··· formula (A)
(R ¹⁵ and R ¹⁶ are each independently hydrogen atom or having 1 to 6 carbon is less hydrocarbon group. However, it is not possible R ¹⁵ and R ¹⁶ are not hydrogen atoms at the same time, also with R ¹⁵ The sum of the carbon number of R ¹⁶ is 6 or less.)

  Examples of the α-olefin contained in the general formula (A) include propene, 1-butene, 1-hexene, 1-octene, 3-methyl-1-pentene, 4-methyl-1-pentene, 3,3- Examples thereof include dimethyl-1-butene, and 1-butene and 1-hexene are more preferable.

The Mv of the ultrahigh molecular weight ethylene copolymer of the present invention is 1 million or more. The ultra high molecular weight ethylene copolymer having an Mv of less than 1 million may significantly deteriorate the abrasion resistance necessary for the copolymer. The Mv of the ultrahigh molecular weight ethylene copolymer of the present invention is η obtained by dissolving the ultrahigh molecular weight ethylene copolymer in decalin at different concentrations and extrapolating the solution viscosity obtained at 135 ° C. to a concentration of 0. It is a value calculated from (dl / g) by the following mathematical formula (4).
Mv = (5.34 × 10 ⁴ ) × η ^1.49 Expression (4)

When the ultrahigh molecular weight ethylene copolymer of the present invention is obtained using, for example, an α-olefin of the above general formula (A), a polymerization unit derived from ethylene (—CH ₂ —CH ₂ —) and It contains polymerized units (—CH ₂ —CR ¹⁵ R ¹⁶ —) derived from the α-olefin of the general formula (A).

In the present invention, the α-olefin content of the ultrahigh molecular weight ethylene copolymer is 0.01 mol% or more and less than 1 mol%, preferably 0.1 mol% or more and less than 1 mol%, More preferably, it is 0.2 mol% or more and less than 1 mol%. Further, the ultrahigh molecular weight ethylene copolymer of the present invention is more than 99 mol% and not more than 99.99 mol% on the basis of polymerized units derived from ethylene and an α-olefin having 3 to 8 carbon atoms, Preferably, it contains more than 99 mol% and 99.9 mol% or less, more preferably more than 99 mol% and 99.8 mol% or less of polymerized units derived from ethylene. In the present invention, the measurement of the olefin content is G.P. J. et al. In accordance with the method disclosed in Ray, et al., Macromolecules 10, 773 (1977), the α-olefin content is measured by using the methylene carbon signal observed by ¹³ C-NMR spectrum, Calculated from

  In the present invention, when the α-olefin content is 1 mol% or more, the density is unnecessarily lowered, and in the suspension polymerization method, because it dissolves in the solvent used or a bulk polymer is produced, Stable continuous operation may be difficult. Also in the gas phase polymerization method, the polymer tends to be sticky and a bulk polymer is produced, or it adheres as a scale to the inner surface of the reactor, so that stable continuous operation may be difficult.

Furthermore, in the ultrahigh molecular weight ethylene copolymer of the present invention, the relationship between the content {x (mol%)} of polymerized units derived from α-olefin and the haze {y (%)} is such that x is 0.00. It is important that the following formula (1) is satisfied in the range of 01 mol% or more and less than 0.4 mol%, and the following formula (2) is satisfied in the range where x is 0.4 mol% or more and less than 1.0 mol%.
−107.5x + 87 ≦ y ≦ −43x + 89 Expression (1)
44 ≦ y ≦ 71.8... Formula (2)

  When x and y satisfy the above relational expression, it means that the ultrahigh molecular weight ethylene copolymer contains the desired α-olefin, and the copolymer has good transparency. . Satisfying the above formula (1) is difficult with techniques other than the present invention.

  In the present invention, the relationship between x and y can be controlled by adjusting the polymerization temperature within a certain range or changing the type and concentration of the catalyst. That is, by adjusting the polymerization temperature within a certain range, the α-olefin is contained relatively uniformly, so that the relationship between x and y can be within the range of the above formula. Moreover, since the α-olefin can be uniformly contained also by changing the type and concentration of the catalyst, the relationship between x and y can be within the range of the above formula.

In the present invention, the ultrahigh molecular weight ethylene copolymer of the present invention has a relationship between the content {x (mol%)} of polymerized units derived from α-olefin and haze {y (%)}, where x is In the range of 0.4 mol% or more and less than 1.0 mol%, it is preferable that the following mathematical formula (3) is satisfied.
44 ≦ y ≦ −43x + 89 Expression (3)
Usually, when the content of the polymerized unit derived from α-olefin increases, the efficiency of improving haze deteriorates. Therefore, the relationship between x and y is generally asymptotic to y as x increases. It was the target. However, according to the present invention, even when x is large, y can be reduced as compared with the prior art.

The ultrahigh molecular weight ethylene copolymer of the present invention preferably satisfies the following formula (4), formula (5) and formula (6) from the viewpoint of improving haze.
−107.5x + 88 ≦ y ≦ −43x + 88 Expression (4)
45 ≦ y ≦ 70.8... Formula (5)
45 ≦ y ≦ −43x + 88 Expression (6)
In the present invention, haze, which is an index of transparency of an ultrahigh molecular weight ethylene copolymer, is a value measured by the method of ASTM D1003. The haze of the ultrahigh molecular weight ethylene copolymer of the present invention is 45% or more and 87.6% or less from the range of Equation 1, Equation 2, and x. When the haze is 45% or more, stable continuous operation is possible without the powders aggregating to form a bulk polymer. When the haze is 87.6% or less, the effect of improving the transparency is sufficiently exhibited.

In the present invention, a press sheet was prepared by pressing an ultrahigh molecular weight ethylene copolymer according to ASTM D1928 Procedure C using a mold having a length of 60 mm, a width of 60 mm, and a thickness of 2 mm. First, an aluminum plate having a thickness of 0.1 mm was placed on a smooth iron plate having a thickness of 5 mm, and a polyethylene terephthalate film having a thickness of 50 μm that was not coated with cellophane was placed thereon. A 60 mm long, 60 mm wide, 2 mm thick mold is placed on this, 8 g of an ultrahigh molecular weight ethylene copolymer is placed thereon, the above polyethylene terephthalate film is placed thereon, and the above aluminum plate is further placed thereon. Furthermore, the above-mentioned iron plate was mounted. This was put into a compression molding machine whose temperature was adjusted to 170 ° C., heated at 170 ° C. for 300 seconds, vented for 5 seconds (100 K / G), and pressurized at 200 K / G for 900 seconds. After the pressurization is completed, the sample is taken out, and after 5 seconds from the removal, it is put into a compression molding machine whose temperature is adjusted to 25 ° C., and is pressurized at 25 ° C. and 100 K / G for 600 seconds at a cooling rate of 15 ± 2 ° C./min. Cooled down. The cooling rate was adjusted by sandwiching the mold with cardboard. After cooling, the removed press sheet was used as a press plate for haze measurement.

Next, the manufacturing method of the ultrahigh molecular weight ethylene copolymer of this invention is demonstrated.
The catalyst for producing the ultrahigh molecular weight copolymer of the present invention is not particularly limited, but by using the catalyst described below, good transparency can be imparted to the obtained copolymer, This is preferred because continuous stable production is possible without the powders agglomerating to form a bulk polymer.

  In the present invention, it is preferable to use an olefin polymerization catalyst comprising a solid catalyst component [A] and a component [B] which is an organomagnesium compound or an organoaluminum compound. The solid catalyst component [A] was prepared by a reaction with an organomagnesium compound soluble in an inert hydrocarbon solvent represented by the general formula (1) and a chlorinating agent represented by the general formula (2). The carrier (A-1) is preferably prepared by supporting the titanium compound (A-2) and the organometallic compound (A-3), and the reaction between the organomagnesium compound and the chlorinating agent is preferably 60. It is preferable to be carried out at a temperature of from 150 ° C.

  In the present invention, the solid catalyst component [A] of the catalyst is preferably composed of a carrier (A-1), a titanium compound (A-2), and an organometallic compound (A-3). The carrier (A-1) is preferably prepared by reacting (A-2) and (A-3). In the present invention, when the carrier (A-1) is not used, it is preferable that the α-olefin is not efficiently contained in the ultrahigh molecular weight ethylene-based copolymer, so that the above formula (1) may not be satisfied. Absent. In the present invention, (A-1) which is the carrier of the solid catalyst component [A] of this catalyst is synthesized by the reaction of an organomagnesium compound soluble in an inert hydrocarbon solvent and a chlorinating agent. Is preferred.

In this invention, it is preferable that the organomagnesium compound used when synthesize | combining (A-1) is represented by following General formula (1).
(M ¹ ) α (Mg) β (R ¹ ) _a (R ² ) _b (OR ³ ) _c Formula (1)
(In the formula, M ¹ is a metal atom belonging to the group consisting of Group 1, Group 2, Group 12 and Group 13 of the Periodic Table; R ¹ , R ² and R ³ are each independently It is a hydrocarbon group having 2 to 20 carbon atoms, and α, β, a, b and c are numbers satisfying the following relationship: 0 ≦ α, 0 <β, 0 ≦ a, 0 ≦ b, 0 ≦ c, 0 <a + b, 0 ≦ c / (α + β) ≦ 2, kα + 2β = a + b + c (where k is the valence of M ¹ ))
This compound is shown as a complex form of organomagnesium soluble in an inert hydrocarbon solvent, but encompasses all dihydrocarbylmagnesium compounds and complexes of this compound with other metal compounds. . The relational expression kα + 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 the general formula (1), the hydrocarbon group represented by R ¹ to R ² is preferably an alkyl group, a cycloalkyl group or an aryl group, and is methyl, ethyl, propyl, butyl, propyl, hexyl, octyl. , Decyl, cyclohexyl, and phenyl groups are more preferable. R ¹ is preferably an alkyl group. When α> 0, the metal atom M ¹ is preferably lithium, sodium, potassium, beryllium, zinc, boron, or aluminum, and more preferably aluminum, boron, beryllium, or zinc.

The ratio β / α of magnesium to 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 an organomagnesium compound with α = 0 is used, any ^{one of} the following three groups (1), (2), and (3) is represented by R ¹ and R ^{2 in} the general formula (1). It is preferable to belong to.
(1) At least one of R ¹ and R ² is a secondary or tertiary alkyl group having 4 to 6 carbon atoms, preferably R ¹ and R ² both have 4 to 6 carbon atoms, At least one is a secondary or tertiary alkyl group.
(2) R ¹ and R ² are alkyl groups having different carbon atoms, preferably R ¹ is an alkyl group having 2 or 3 carbon atoms, and R ² is an alkyl group having 4 or more carbon atoms. Be a group.
(3) At least one of R ¹ and R ² is a hydrocarbon group having 6 or more carbon atoms, preferably an alkyl group that becomes 12 or more when the number of carbon atoms contained in R ¹ and R ² is added. .

  These groups are specifically shown below. The secondary or tertiary alkyl group having 4 to 6 carbon atoms in (1) includes 1-methylpropyl group, 2-methylpropyl group, 1,1-dimethylethyl group, 2-methylbutyl group, 2- Preferred are ethylpropyl group, 2,2-dimethylpropyl group, 2-methylpentyl group, 2-ethylbutyl group, 2,2-dimethylbutyl group, 2-methyl-2-ethylpropyl group, and 1-methylpropyl group is more preferable. preferable.

  In (2), the alkyl group having 2 or 3 carbon atoms is preferably an ethyl group, a 1-methylethyl group, or a propyl group, and more preferably an ethyl group. Examples of the alkyl group having 4 or more carbon atoms include a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, and the like, and a butyl group and a hexyl group are more preferable.

In (3), the hydrocarbon group having 6 or more carbon atoms is preferably a hexyl group, heptyl group, octyl group, nonyl group, decyl group, phenyl group or 2-naphthyl group. Among the hydrocarbon groups, an alkyl group is preferable, and among the alkyl groups, a hexyl group and an octyl group are particularly preferable. In general, an increase in the number of carbon atoms contained in an alkyl group facilitates dissolution in an inert hydrocarbon solvent. However, the use of an unnecessarily long alkyl group is not preferred in terms of handling because the solution viscosity increases. The organomagnesium compound is used as an inert hydrocarbon solution, but it can be used as long as a trace amount of Lewis basic compounds such as ethers, esters, and amines are contained or remain in the solution.

Next, the alkoxy group (OR ³ ) of the general formula (1) will be described. The hydrocarbon group represented by R ³ 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. Specifically, for example, methyl group, ethyl group, propyl group, 1-methylethyl group, butyl group, 1-methylpropyl group, 1,1-dimethylethyl group, pentyl group, hexyl group, 2-methylpentyl group 2-ethylbutyl group, 2-ethylpentyl group, 2-ethylhexyl group, 2-ethyl-4-methylpentyl group, 2-propylheptyl group, 2-ethyl-5-methyloctyl group, octyl group, nonyl group, decyl Group, phenyl group and naphthyl group are preferable, and butyl group, 1-methylpropyl group, 2-methylpentyl group and 2-ethylhexyl group are more preferable.

The organomagnesium compound of the above general formula (1) includes an organomagnesium compound belonging to the group consisting of the general formulas R ¹ MgX and R ¹ ₂ Mg (R ¹ is as defined above, X is halogen), An organometallic compound belonging to the group consisting of the formulas M ¹ R ² _k and M ¹ R ² _(k-1) H (M ¹ , R ² , k are as defined above) in an inert hydrocarbon solvent at room temperature Reaction between ˜150 ° C. and, if necessary, subsequently having the hydrocarbon group represented by R ³ soluble in an alcohol having an hydrocarbon group represented by R ³ or an inert hydrocarbon solvent It is synthesized by a method of reacting with an alkoxymagnesium compound and / or an alkoxyaluminum compound.

Among these, there is no particular limitation on the order of addition when reacting an organomagnesium compound soluble in an inert hydrocarbon solvent with an alcohol, a method of adding alcohol to the organomagnesium compound, an organomagnesium compound in the alcohol Any of the method of adding the above, or the method of adding both at the same time can be used. In the present invention, the reaction ratio between the organomagnesium compound soluble in the inert hydrocarbon solvent and the alcohol is not particularly limited, but as a result of the reaction, the alkoxy group-containing organomagnesium compound in the resulting alkoxy group-containing organomagnesium compound contains all of the alkoxy groups. The range of the molar composition ratio c / (α + β) is 0 ≦ c / (
More preferably, α + β) ≦ 2 and 0 ≦ c / (α + β) <1.

  Examples of the inert hydrocarbon solvent in the present invention include aliphatic hydrocarbons such as pentane, hexane, and heptane, aromatic hydrocarbons such as benzene and toluene, and alicyclic hydrocarbons such as cyclohexane and methylcyclohexane.

In the present invention, the chlorinating agent used when synthesizing (A-1) is represented by the following general formula (2), at least one of which is a silicon chloride compound having a Si—H bond. .
H _d SiCl _e R ⁴ _{(4- (d + e))} (2)
(Wherein R ⁴ is a hydrocarbon group having 1 to 12 carbon atoms, and d and e are real numbers satisfying the following relationship: 0 <d, 0 <e, 0 <d + e ≦ 4)
Although there is no restriction | limiting in particular in the hydrocarbon group represented by R < ⁴ > in said General formula (2), An aliphatic hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group are preferable, and C1-C10 And more preferably an alkyl group having 1 to 3 carbon atoms. Specifically, a methyl group, an ethyl group, a propyl group, a 1-methylethyl group, a butyl group, a pentyl group, a hexyl group, an octyl group, a decyl group, a cyclohexyl group, and a phenyl group are preferable. And more preferably a group, a propyl group, and a 1-methylethyl group. D and e are numbers larger than 0 satisfying the relationship of d + e ≦ 4, and e is 2
Or it is preferably 3.

These silicon chloride compounds include HSiCl ₃ , HSiCl ₂ CH ₃ , HSiCl ₂ C ₂ H ₅ , HSiCl ₂ C ₃ H ₇ , HSiCl ₂ (1-CH ₃ C ₂ H ₅ ), 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 SiClCH ₃ , H ₂ SiClC ₂ H ₅ , HSiCl (CH ₃ ) ₂ , HSiCl (C ₂ H ₅ ) ₂ , HSiClCH ₃ (1-CH ₃ C ₂ H ₅ ), HSiClCH ₃ ( _{C 6 H 5), HSiCl (} C 6 H 5) 2 and the _{like, HSiCl 3, HSiCl 2 CH 3} , HSiCl (CH 3) are preferred _{2, HSiCl 2 C 2 H 5} , HSiCl 3, HSiCl 2 CH 3 Is special Is preferable. These compounds can be used alone or as a mixture of two or more selected from these compounds.

  Next, the reaction between the organomagnesium compound and the silicon chloride compound in the present invention will be described. The reaction between the organomagnesium compound and the chlorinating agent is preferably performed at 60 ° C. or higher and 150 ° C. or lower, and more preferably 65 ° C. or higher. If the temperature of this reaction is less than 60 ° C., the reaction may not proceed sufficiently, and if it exceeds 150 ° C., side reactions such as decomposition of the silicon chloride compound may proceed.

  In the reaction, the silicon chloride compound is preliminarily used as a reaction solvent, for example, the above inert hydrocarbon solvent, chlorinated hydrocarbons such as 1,2-dichloroethane, o-dichlorobenzene, dichloromethane, or ethers such as diethyl ether and tetrahydrofuran. It is preferable to use after diluting with a medium or a mixed medium thereof. In particular, in view of the performance of the catalyst, an inert hydrocarbon solvent is preferable. Although there is no restriction | limiting in particular in the reaction ratio of an organomagnesium compound and a silicon chloride compound, Usually, it is 0.01-100 mol of silicon chloride compounds with respect to 1 mol of organomagnesium compounds, Preferably, with respect to 1 mol of organomagnesium compounds, It is the range of 0.1-10 mol of silicon chloride compounds.

There is no particular restriction on the reaction method, but a method of simultaneous addition in which an organomagnesium compound and a silicon chloride compound are introduced into the reactor at the same time and a reaction is performed, and the organomagnesium compound is reacted after the silicon chloride compound is charged in the reactor in advance. The method of introducing into the reactor or the method of introducing the organomagnesium compound into the reactor in advance and then introducing the silicon chloride compound into the reactor is preferred, and the organomagnesium compound is introduced into the reactor after the silicon chloride compound is introduced into the reactor in advance. More preferably, the method is introduced into. The solid component obtained by the above reaction may be used after separation by filtration or decantation, followed by thorough washing with an inert hydrocarbon solvent to remove unreacted products or by-products. preferable.

In the present invention, the carrier (A-1) can also be prepared by reacting an organomagnesium compound and a silicon chloride compound in the presence of a solid. This solid may be either an inorganic solid or an organic solid, but it is preferable to use an inorganic solid. The inorganic solid is not particularly limited, but the following are preferable:
(I) inorganic oxides;
(Ii) inorganic carbonates, silicates, sulfates;
(Iii) inorganic hydroxides;
(Iv) inorganic halides;
(V) Double salt, solid solution or mixture comprising (i) to (iv).

The inorganic solid is not particularly limited, but silica, alumina, silica / alumina, hydrated alumina, magnesia, tria, titania, zirconia, calcium phosphate / barium sulfate, calcium sulfate, magnesium silicate, magnesium / calcium, aluminum silicate [( Mg · Ca) O · Al ₂ O ₃ · 5SiO ₂ · nH ₂ O], potassium silicate · aluminum [K ₂ O · 3Al ₂ O ₃ · 6SiO ₂ · 2H ₂ O], magnesium iron silicate [(Mg · Fe) ₂ SiO ₄ ], aluminum silicate [Al ₂ O ₃ .SiO ₂ ], calcium carbonate, magnesium chloride and magnesium iodide are preferred, and silica, silica / alumina and magnesium chloride are more preferred. No particular limitation is imposed on the specific surface area of the inorganic solid but, is preferably 20 m ² / g or more, more preferably 90m ² / g or more.

  In the present invention, the support of the titanium compound (A-2) and the organometallic compound (A-3) on the support (A-1) is supported on the support (A-1) by the titanium compound (A-2) and the organometallic compound. The reaction is preferably carried out by reacting (A-3).

In the present invention, (A-2) is preferably a titanium compound represented by the following general formula (3).
Ti (OR ⁵ ) _f X ¹ _(4-f) Formula (3)
(In the formula, f is a real number of 0 or more and 4 or less, R ⁵ is a hydrocarbon group of 1 to 20 carbon atoms, and X ¹ is a halogen atom.)
Examples of the hydrocarbon group represented by R ⁵ include aliphatic hydrocarbon groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, 2-ethylhexyl, heptyl, octyl, decyl, and allyl groups, cyclohexyl, and 2-methylcyclohexyl. And alicyclic hydrocarbon groups such as cyclopentyl group, aromatic hydrocarbon groups such as phenyl and naphthyl groups, and the like, and aliphatic hydrocarbon groups are preferred. Examples of the halogen atom represented by X ¹ include chlorine, bromine and iodine, with chlorine being preferred. Two or more kinds of (A-2) selected from the above can be mixed and used.

  Although there is no restriction | limiting in particular in the usage-amount of (A-2), 0.01-20 is preferable in molar ratio with respect to the magnesium atom contained in a support | carrier, 0.05-10 is especially preferable. When the amount of the titanium compound (A-2) used is greater than 20 in terms of the molar ratio to the magnesium atom contained in the carrier, the α-olefin is not efficiently contained in the ultrahigh molecular weight ethylene copolymer, This is not preferable because there is a possibility that the above formula (1) may not be satisfied. Moreover, when the usage-amount of a titanium compound (A-2) is smaller than 0.01 by molar ratio with respect to the magnesium atom contained in a support | carrier, productivity of the ultra high molecular weight ethylene copolymer per catalyst is notable. This is not preferable because it may decrease.

Next, the organometallic compound (A-3) will be described. In the present invention, (A-3) is preferably an organometallic compound represented by the following general formula (4).
(M ² ) γ (Mg) ε (R ⁶ ) _h (R ⁷ ) _i Y _j Expression (4)
(In the formula, M ² is a metal atom belonging to the group consisting of Group 1, Group 2, Group 12 and Group 13 of the periodic table, and R ⁶ and R ⁷ each independently represent 2 carbon atoms. 20 or less hydrocarbon group, Y is alkoxy, siloxy, allyloxy, amino, amide, —N═C—R ⁸ R ⁹ , —SR ¹⁰ (where R ⁸ , R ⁹ and R ¹⁰ are each Independently represents a hydrocarbon group having 2 to 20 carbon atoms), β-keto acid residues, and γ, ε, h, i and j are real numbers satisfying the following relationship: 0 ≦ γ, 0 <ε, 0 ≦ h, 0 ≦ i, 0 <h + i, 0 ≦ j / (γ + ε) ≦ 2, nγ + 2ε = h + i + j (where n is the valence of M ² ))
The organometallic compound represented by the general formula (4) is shown as a complex form of organomagnesium soluble in an inert hydrocarbon solvent, and dihydrocarbylmagnesium compound and this compound and other metal compounds And all of the complexes. The relational expression nγ + 2ε = h + i + j of the symbols γ, ε, h, i, j indicates the stoichiometry between the valence of the metal atom and the substituent.

The hydrocarbon groups represented by R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ in the general formula (4) are each independently an alkyl group, a cycloalkyl group or an aryl group, and an alkyl group It is preferable that Specifically, a methyl group, an ethyl group, a propyl group, a butyl group, a propyl group, a hexyl group, an octyl group, a decyl group, and a cyclohexyl group are preferable. When γ> 0, the metal atom M ² is a metal element belonging to the group consisting of Groups 1 to 3 of the periodic table, and is preferably lithium, sodium, potassium, beryllium, zinc, boron, aluminum, More preferred are aluminum, boron, beryllium and zinc.

The ratio ε / 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 an organomagnesium compound with γ = 0 is used, R ⁶ and R ⁷ preferably belong to any one of the following three groups (1), (2), and (3).
(1) At least one of R ⁶ and R ⁷ is a secondary or tertiary alkyl group having 4 to 6 carbon atoms, preferably R ⁶ and R ⁷ both have 4 to 6 carbon atoms, At least one is a secondary or tertiary alkyl group.
(2) R ⁶ and R ⁷ are alkyl groups having different carbon atoms, preferably R ⁶ is an alkyl group having 2 or 3 carbon atoms, and R ⁷ is an alkyl group having 4 or more carbon atoms. Be a group.
(3) At least one of R ⁶ and R ⁷ is a hydrocarbon group having 6 or more carbon atoms, preferably an alkyl group that becomes 12 or more when the number of carbon atoms contained in R ⁶ and R ⁷ is added. .

  These groups are specifically shown below. The secondary or tertiary alkyl group having 4 to 6 carbon atoms in (1) includes 1-methylpropyl group, 2-methylpropyl group, 1,1-dimethylethyl group, 2-methylbutyl group, 2- Preferred are ethylpropyl group, 2,2-dimethylpropyl group, 2-methylpentyl group, 2-ethylbutyl group, 2,2-dimethylbutyl group, 2-methyl-2-ethylpropyl group, and 1-methylpropyl group is more preferable. preferable.

  In (2), the alkyl group having 2 or 3 carbon atoms is preferably an ethyl group, a 1-methylethyl group, or a propyl group, and more preferably an ethyl group. The alkyl group having 4 or more carbon atoms is preferably a butyl group, a pentyl group, a hexyl group, a heptyl group or an octyl group, more preferably a butyl group or a hexyl group.

In (3), the hydrocarbon group having 6 or more carbon atoms is preferably a hexyl group, heptyl group, octyl group, nonyl group, decyl group, phenyl group or 2-naphthyl group. Among the hydrocarbon groups, an alkyl group is preferable, and among the alkyl groups, a hexyl group and an octyl group are particularly preferable. In general, an increase in the number of carbon atoms contained in an alkyl group facilitates dissolution in an inert hydrocarbon solvent. However, the use of an unnecessarily long alkyl group is not preferred in terms of handling because the solution viscosity increases. The organomagnesium compound is used as an inert hydrocarbon solution, but it can be used as long as a trace amount of Lewis basic compounds such as ethers, esters, and amines are contained or remain in the solution.

Next, Y will be described. Y is an alkoxy group, a siloxy group, an allyloxy group, an amino group, an amide group, -N = C-R ⁸ R ⁹ , -SR ¹⁰ (where R ⁸ , R ⁹ and R ¹⁰ have 2 to 20 carbon atoms. Β-keto acid residue (which represents a hydrocarbon group), preferably an alkoxy group or a siloxy group.

No particular limitation is imposed on the synthesis method of an organometallic compound represented by the above general formula (4), a method of reacting an organometallic compound containing an organic magnesium compound and M ² having a substituent Y, the organomagnesium compound And a method of reacting an organometallic compound containing M ² having a substituent Y, a method of reacting an organomagnesium compound having substituent Y and an organometallic compound containing M ² having substituent Y, and an organomagnesium compound A method of reacting a compound that generates a Y residue after reacting with an organometallic compound containing M ² is preferred.

Specifically, an organomagnesium compound belonging to the group consisting of the general formulas R ⁶ MgY and R ⁶ ₂ Mg (R ⁶ and Y are as defined above), and the general formulas M ² R ⁷ _k and M ² R ⁷ _{( k-1)} reacting an organometallic compound belonging to the group consisting of H (M ² , R ⁷ , k is as defined above) in an inert hydrocarbon solvent in a range of 25 ° C. to 150 ° C., If necessary, a method of subsequently reacting with a compound represented by YH (Y is as defined above) is preferred. This reaction is preferably carried out in an inert hydrocarbon solvent. Although there is no restriction | limiting in particular in the temperature of reaction, It is preferable that it is 25 to 150 degreeC. As a result of this reaction, the range of the molar composition ratio j / (γ + ε) ≦ 2 of Y groups with respect to all metal atoms in the obtained organomagnesium compound is 0 ≦ j / (γ + ε) ≦ 2, and 0 <j / (γ + ε) < 1 is preferable.

  The amount of (A-3) used is preferably 0.01 or more and 20 or less, and particularly preferably 0.05 or more and 10 or less, in terms of the molar ratio of Mg contained in (A-3) to magnesium contained in the carrier. When the amount of the organometallic compound (A-3) used is greater than 20 in terms of the molar ratio of Mg contained in (A-3) to magnesium atoms contained in the carrier, the α-olefin is an ultrahigh molecular weight ethylene copolymer. Since it is not contained efficiently in the polymer, there is a possibility that the above formula (1) may not be satisfied. Further, when the amount of the organometallic compound (A-3) used is smaller than 0.01 in terms of the molar ratio of Mg contained in (A-3) to magnesium atoms contained in the carrier, the ultrahigh molecular weight per catalyst This is not preferable because the productivity of the ethylene-based copolymer may be significantly reduced.

  Next, the reaction of the carrier (A-1) with the titanium compound (A-2) and the organometallic compound (A-3) will be described. This reaction is preferably performed in an inert solvent, and more preferably in an aliphatic hydrocarbon solvent such as hexane or heptane. Although there is no restriction | limiting in particular about the temperature of this reaction, It is preferable to carry out in the range of -80 degreeC-150 degreeC, and it is more preferable to carry out in the range of -40 degreeC-100 degreeC. The order of adding (A-2) and (A-3) to the carrier (A-1) is not particularly limited, and (A-2) is added following (A-2). Any method of adding (A-2) following (3) and adding (A-2) and (A-3) at the same time is possible, but (A-2) and (A-3) are possible. ) Are preferably added simultaneously. The molar ratio of (A-3) to (A-2) is preferably in the range of 0.1 to 10, and more preferably in the range of 0.5 to 5. When the molar ratio of (A-3) to (A-2) is larger than 10, the α-olefin is not efficiently contained in the ultrahigh molecular weight ethylene copolymer, and thus the above formula (1). Is not preferable because there is a risk that Moreover, when the molar ratio of (A-3) to (A-2) is smaller than 0.1, the productivity of the ultrahigh molecular weight ethylene copolymer per catalyst may be significantly reduced. It is not preferable. The solid catalyst component [A] thus obtained is preferably used as a slurry solution using an inert hydrocarbon solvent.

  The solid catalyst component [A] of the present invention is combined with the component [B], which is an organomagnesium compound or an organoaluminum compound, to provide a more highly active polymerization catalyst.

As the organomagnesium compound of component [B], those represented by the general formula (5) are preferable.
(M ³ ) κ (Mg) λ (R ¹¹ ) _p (R ¹² ) _q (OR ¹³ ) _r Expression (5)
(In the formula, M ³ is a metal atom belonging to the group consisting of Group 1, Group 2, Group 12 and Group 13 of the Periodic Table; R ¹¹ , R ¹² and R ¹³ are each independently It is a hydrocarbon group having 2 to 20 carbon atoms, and κ, λ, p, q and r are numbers satisfying the following relationship: 0 ≦ κ, 0 <λ, 0 ≦ p, 0 ≦ q, 0 ≦ r, 0 <p + q, 0 ≦ r / (κ + λ) ≦ 2, kκ + 2λ = p + q + r (where k is the valence of M ³ ))
This compound is shown as a complex form of organomagnesium soluble in an inert hydrocarbon solvent, but includes all dialkylmagnesium compounds and complexes of this compound with other metal compounds. κ, λ, p, q, r, M ³ , R ¹¹ , R ¹² , and OR ¹³ are as described above. However, since a compound soluble in an inert hydrocarbon solvent is desirable, λ / κ is 0. It is preferable that it is in the range of 5 to 10, and a compound in which M ³ is aluminum is more preferable.

As the organoaluminum compound of component [B], those represented by the following general formula (6) are preferable.
AlR ¹⁴ _s X ² _3-s (6)
(In the formula, each R ¹⁴ independently represents a linear, branched or cyclic alkyl group having 1 to 12 carbon atoms or an aryl group having 6 to 20 carbon atoms, and X ² is each independently A halide, a hydride, or an alkoxide group having 1 to 10 carbon atoms, and s is a real number of 1 to 3)
Preferred organoaluminum compounds include trimethylaluminum, triethylaluminum, tripropylaluminum, triisobutylaluminum, tri (2-methylpropyl) aluminum, tripentylaluminum, tri (3-methylbutyl) aluminum, trihexylaluminum, trioctylaluminum, Trialkylaluminum such as tridecylaluminum, dialkylaluminum halide such as diethylaluminum halide, diisobutylaluminum halide, diethylaluminum chloride, ethylaluminum dichloride, di (2-methylpropyl) aluminum chloride, ethylaluminum sesquichloride, diethylaluminum bromide Aluminum halide compounds, diethylaluminum Preferred are alkoxyaluminum compounds such as muethoxide, di (2-methylpropyl) aluminum butoxide, siloxyaluminum compounds such as dimethylhydrosiloxyaluminum dimethyl, ethylmethylhydrosiloxyaluminum diethyl, ethyldimethylsiloxyaluminum diethyl, and mixtures thereof, trimethylaluminum, More preferred are triethylaluminum, tripropylaluminum, triisobutylaluminum, tri (2-methylpropyl) aluminum, trihexylaluminum, trioctylaluminum, and diisobutylaluminum halide.

  There is no particular limitation on the reaction method of the solid catalyst component [A] and the component [B] which is an organomagnesium compound or organoaluminum compound, but it is preferable to add both to the polymerization system separately under the polymerization conditions. When it is added to the polymerization system after reacting in advance, it is preferable because the α-olefin is not efficiently contained in the ultrahigh molecular weight ethylene-based copolymer, so that the above formula (1) may not be satisfied. Absent. The ratio of both components to be combined is preferably in the range of 1 mmol to 100 mmol of the component [B] which is an organomagnesium compound or organoaluminum compound with respect to 1 g of the solid catalyst component [A]. When the ratio of the component [B] which is an organomagnesium compound or organoaluminum compound to 1 g of the solid catalyst component [A] is larger than 100 mmol, the α-olefin is efficiently contained in the ultrahigh molecular weight ethylene copolymer. This is not preferable because there is a possibility that the numerical formula (1) is not satisfied. In addition, when the ratio of the component [B] which is an organomagnesium compound or an organoaluminum compound to 1 g of the solid catalyst component [A] is less than 1 millimolar, the reaction does not proceed sufficiently, so This is not preferable because the productivity of the high molecular weight ethylene copolymer may be significantly reduced.

  The ultrahigh molecular weight ethylene copolymer of the present invention can be produced by copolymerizing ethylene and an α-olefin by suspension polymerization or gas phase polymerization. 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.

  Specific examples of the inert hydrocarbon medium include aliphatic hydrocarbons such as propane, butane, isobutane, pentane, isopentane, hexane, heptane, octane, decane, dodecane, and kerosene; cyclopentane, cyclohexane, and methylcyclopentane. And alicyclic hydrocarbons such as benzene, toluene, xylene and the like; halogenated hydrocarbons such as ethyl chloride, chlorobenzene and dichloromethane, and mixtures thereof.

  The polymerization temperature in the present invention is usually preferably 40 ° C. or higher, more preferably 50 ° C. or higher, still more preferably 60 ° C. or higher and 100 ° C. or lower, more preferably 85 ° C. or lower. When the polymerization temperature is lower than 40 ° C., the α-olefin is not preferably contained in the ultrahigh molecular weight ethylene copolymer, which may not satisfy the above formula (1). In addition, when the polymerization temperature is higher than 100 ° C., the deactivation reaction of the catalyst proceeds preferentially, which may significantly reduce the productivity of the ultrahigh molecular weight ethylene copolymer per catalyst. Therefore, it is not preferable.

  Usually, the polymerization pressure is preferably normal pressure or higher and 2 MPa or lower, more preferably 0.1 MPa or higher and 1.5 MPa or lower, more preferably 0.1 MPa or higher and 1.0 MPa or lower. It can be carried out by either a semi-continuous method or a continuous method.

  The method for adjusting the molecular weight of the polymer to be obtained is not particularly limited. For example, the concentration of hydrogen present in the polymerization system, the polymerization temperature is changed, or the component is an organomagnesium compound or organoaluminum compound. It can be adjusted by changing the concentration of [B] or changing the concentration of the α-olefin having 3 to 8 carbon atoms.

  It is also possible to carry out the polymerization in two or more stages having different reaction conditions. Furthermore, as described in, for example, West German Patent Publication No. 3127133, the molecular weight of the resulting olefin polymer is adjusted by the presence of hydrogen in the polymerization system or by changing the polymerization temperature. You can also In addition, in this invention, the other component useful for manufacture of ultra high molecular weight ethylene copolymer other than each above components can be included.

  The ultrahigh molecular weight ethylene copolymer of the present invention can be molded using the same molding method as that of ordinary ultrahigh molecular weight polyethylene. For example, the ultra high molecular weight polyethylene powder of the present invention is obtained by various known molding methods such as a method of putting ultra high molecular weight polyethylene powder in a mold and compression molding with heating for a long time or extrusion molding with a ram extruder. be able to.

  Further, as the molded article of the ultrahigh molecular weight ethylene copolymer of the present invention, the ultrahigh molecular weight ethylene copolymer is mixed with an appropriate solvent or plasticizer, extruded into a film, stretched, and then used as a solvent or A microporous film that can be obtained by extracting a plasticizer is also included. This film can be used for battery separators and the like. In this case, a film mixed with an inorganic material such as silica can be used.

  Furthermore, the ultrahigh molecular weight ethylene copolymer powder of the present invention is dissolved or mixed in an appropriate solvent or plasticizer to prepare a gel mixture, and ultrahigh elastic modulus and high strength fibers are obtained by a known gel spinning technique. You can also.

The present invention will be described based on examples.
[Measurement of viscosity average molecular weight (Mv)]
20 mg of decalin was charged with 20 mg of polymer and stirred at 150 ° C. for 2 hours to dissolve the polymer. The dropping time (t _s ) between the marked lines was measured using a Ubbelohde type viscometer with the solution at a high temperature of 135 ° C. Incidentally, not putting the polymer as a blank was measured drop time of only decahydronaphthalene a (t _b). The specific viscosity (η _sp / C) of the polymer was plotted according to the following formula (9), and the intrinsic viscosity (η) extrapolated to a concentration of 0 was determined.
η _sp / C = (t _s / t _b −1) /0.1 (9)
From this η, the viscosity average molecular weight (Mv) was determined according to the following formula (10).
Mv = (5.34 × 10 ⁴ ) × η ^1.49 Expression (10)

[Create press sheet]
A press sheet was prepared by pressing an ultrahigh molecular weight ethylene copolymer in accordance with ASTM D1928 Procedure C using a mold having a length of 60 mm, a width of 60 mm, and a thickness of 2 mm. First, an aluminum plate having a thickness of 0.1 mm was placed on a smooth iron plate having a thickness of 5 mm, and a polyethylene terephthalate film having a thickness of 50 μm that was not coated with cellophane (Lumirror manufactured by Toray Industries, Inc.) was placed thereon. A 60 mm long, 60 mm wide, 2 mm thick mold is placed on this, 8 g of an ultrahigh molecular weight ethylene copolymer is placed thereon, the above polyethylene terephthalate film is placed thereon, and the above aluminum plate is further placed thereon. Furthermore, the above-mentioned iron plate was mounted. This was put into a compression molding machine (SFA-37 manufactured by Shindo Metal Industry Co., Ltd.) whose temperature was adjusted to 170 ° C., heated at 170 ° C. for 900 seconds, evacuated at 10 MPa for 5 seconds, and heated at 20 MPa for 300 seconds. Pressure was applied. After completion of pressurization, the sample is taken out, and after 5 seconds from taking out, the sample is put into a compression molding machine (SFA-37 manufactured by Kondo Metal Industry Co., Ltd.) whose temperature is adjusted to 25 ° C. and pressurized at 10 MPa at 25 ° C. for 600 seconds. Cooling was performed at a cooling rate of 15 ± 2 ° C./min. The cooling rate was adjusted by sandwiching the mold with cardboard. After cooling, the removed press sheet was used for haze measurement.

[Measurement of haze]
Haze was measured by the method of ASTM D 1003 using a haze meter (HM-100 manufactured by Murakami Color Research Laboratory). The press sheet was used as a test piece.
[Measurement of content of polymerized unit derived from α-olefin]
The measurement of the content {x (mol%)} of polymerized units derived from an α-olefin is as described in G. J. et al. This was performed according to the method disclosed in Ray et al., Macromolecules, 10, 773 (1977), and x was calculated from the area intensity using a signal of methylene carbon observed by a ¹³ C-NMR spectrum. The equipment used was Lambda-400 manufactured by JEOL. The solvent used was orthodichlorobenzene-d ₄ , the measurement temperature was 140 ° C., the observation frequency was 100 MHz ( ¹³ C), the pulse width was 45 ° (7.5 μsec), and the number of integrations was 10,000. The measurement standard was PE (-eeee-) signal, which was 29.9 ppm.

[Reference Example 1]
Preparation of solid catalyst component [A] (Synthesis of carrier (A-1))
A 1 mol milliliter of a 2 mol / liter hydroxytrichlorosilane hexane solution was charged into an 8 liter stainless steel autoclave thoroughly purged with nitrogen, and the composition formula AlMg ₅ (C ₄ H ₉ ) ₁₁ (OC ₄ H ₉ ) was stirred at 80 ° C. 3730 ml of an organic magnesium compound represented by ₂ (corresponding to 2.68 mol of magnesium) was added dropwise over 4 hours, and the reaction was continued while stirring at 80 ° C. for 1 hour. After completion of the reaction, the supernatant was removed, and the carrier (A-1) was prepared by washing 4 times with 2600 ml of hexane. As a result of analyzing this support, the amount of magnesium contained per 1 g of the support was 8.43 mmol.
(Preparation of solid catalyst component [A])
While stirring at 20 ° C. in 2880 ml of hexane slurry containing 160 g of the carrier (A-1), 160 ml of 1 mol / liter titanium tetrachloride hexane solution as (A-2) and 1 mol / liter as (A-3) One hundred liters of an organic magnesium compound hexane solution represented by the composition formula AlMg ₅ (C ₄ H ₉ ) ₁₁ (OSiH (C ₂ H ₅ ) ₂ ) ₂ was added simultaneously over 1 hour. After the addition, the reaction was continued at 20 ° C. for 1 hour. After completion of the reaction, 1600 ml of the supernatant was removed, and the solid catalyst component [A] was prepared by washing twice with 1600 ml of hexane. The amount of titanium contained in 1 g of this solid catalyst component was 0.98 mmol.

[Reference Example 2]
Preparation of solid catalyst component [C] 1600 milliliters of hexane was added to an 8 liter stainless steel autoclave sufficiently purged with nitrogen. While stirring at 20 ° C., 800 ml of a 1 mol / liter titanium tetrachloride hexane solution as (A-2) and 1 mol / liter of a composition of AlMg ₅ (C ₄ H ₉ ) ₁₁ (OSiH ( 800 mL of a hexane solution of an organomagnesium compound represented by C ₂ H ₅ ) ₂ ) ₂ was simultaneously added over 1 hour. After the addition, the temperature was raised slowly, and the reaction was continued at 20 ° C. for 1 hour. After completion of the reaction, 1600 ml of the supernatant was removed, and the solid catalyst component [C] was prepared by washing twice with 1600 ml of hexane. The amount of titanium contained in 1 g of this solid catalyst component was 3.61 mmol.

[Example 1]
As an organoaluminum compound of component [B], 0.4 ml of isobutylaluminum hydride was dehydrated and deoxygenated together with 0.8 liter of hexane and 2.5 ml of 1-butene, and the inside volume was degassed and replaced with nitrogen. Placed in a 5 liter autoclave. Next, the inside of the autoclave was kept at 70 ° C., and then 10 mg of the solid catalyst component [A] was added. Thereafter, the polymerization was started by adding ethylene to bring the total pressure to 0.2 MPa. Polymerization was carried out at 70 ° C. for 60 minutes while keeping the total pressure at 0.2 MPa by continuously supplying ethylene. The polymerization slurry was extracted, deactivated with methanol, filtered and dried at 90 ° C. for 1 hour. The polymer yield of the ultrahigh molecular weight ethylene copolymer thus obtained was 180 g, and the polymerization activity per 1 g of the catalyst was 18000 g / g-catalyst. The η in decalin (135 ° C.) was 14.5 dl / g, and the Mv determined from this η was 2.9 million. The haze y, which is an index of transparency, was 70% and was very excellent in transparency. x was 0.3 mol%. Table 1 includes other values. These x and y satisfied the above mathematical formula (1).

[Comparative Example 1]
Polymerization was performed in the same manner as in Example 1 except that 10 mg of the solid catalyst component [C] was used as the solid catalyst component. The polymer yield of the ultrahigh molecular weight ethylene copolymer obtained by this polymerization was 300 g, and the polymerization activity per 1 g of the catalyst was 30000 g / g-catalyst. The η in decalin (135 ° C.) was 12.8 dl / g, and the Mv determined from this η was 2.4 million. The haze as an index of transparency was 77%, which was inferior to that of Example 1. x was 0.3 mol%. Table 1 includes other values. This x and y did not satisfy the above formula (1).

[Example 2]
Polymerization was carried out in the same manner as in Example 1 except that the amount of 1-butene was changed to 5 ml. The polymer yield of the ultrahigh molecular weight ethylene copolymer thus obtained was 200 g, and the polymerization activity per 1 g of the catalyst was 20000 g / g-catalyst. Η in decalin (135 ° C.) was 14.0 dl / g, and Mv determined from this η was 2.7 million. The haze y as an index of transparency was 66%, and x was 0.4 mol%. Table 1 includes other values. These x and y satisfied the above formulas (2) and (3).

[Example 3]
Polymerization was carried out in the same manner as in Example 1 except that the amount of 1-butene was changed to 10 ml. The polymer yield of the ultrahigh molecular weight ethylene copolymer thus obtained was 250 g, and the polymerization activity per 1 g of the catalyst was 25000 g / g-catalyst. The η in decalin (135 ° C.) was 13.6 dl / g, and the Mv determined from this η was 2.6 million. The haze y as an index of transparency was 56%, and x was 0.6 mol%. Table 1 includes other values. The x and y satisfied the above mathematical expressions (2) and (3).

[Example 4]
Polymerization was carried out in the same manner as in Example 1 except that the amount of 1-butene was 20 ml. The polymer yield of the ultrahigh molecular weight ethylene copolymer thus obtained was 300 g, and the polymerization activity per 1 g of the catalyst was 30000 g / g-catalyst. The η in decalin (135 ° C.) was 12.0 dl / g, and the Mv determined from this η was 2.2 million. The haze y as an index of transparency was 52%, and x was 0.8 mol%. Table 1 includes other values. The x and y satisfied the above mathematical expressions (2) and (3).

[Example 5]
Polymerization was carried out in the same manner as in Example 3 except that the polymerization temperature was 60 ° C. The polymer yield of the ultrahigh molecular weight ethylene copolymer thus obtained was 200 g, and the polymerization activity per 1 g of the catalyst was 20000 g / g-catalyst. Η in decalin (135 ° C.) was 14.0 dl / g, and Mv determined from this η was 2.7 million. The haze y as an index of transparency was 60%, and x was 0.6 mol%. Table 1 includes other values. The x and y satisfied the above mathematical expressions (2) and (3).

[Example 6]
Polymerization was carried out in the same manner as in Example 1 except that the polymerization temperature was 50 ° C. and the amount of 1-butene was 25 ml. The polymer yield of the ultrahigh molecular weight ethylene copolymer thus obtained was 150 g, and the polymerization activity per 1 g of the catalyst was 15000 g / g-catalyst. Η in decalin (135 ° C.) was 12.4 dl / g, and Mv determined from this η was 2.3 million. The haze y as an index of transparency was 67%, and x was 0.8 mol%. Table 1 includes other values. The x and y satisfied the above mathematical formula (2).

[Example 7]
Polymerization was carried out in the same manner as in Example 1 except that the polymerization temperature was 75 ° C. and the amount of 1-butene was 25 ml. The polymer yield of the ultrahigh molecular weight ethylene copolymer thus obtained was 150 g, and the polymerization activity per 1 g of the catalyst was 34000 g / g-catalyst. Η in decalin (135 ° C.) was 9.8 dl / g, and Mv obtained from this η was 1,600,000. The haze y as an index of transparency was 46%, and x was 0.9 mol%. Table 1 includes other values. The x and y satisfied the above mathematical expressions (2) and (3).

[Example 8]
Polymerization was carried out in the same manner as in Example 1 except that the polymerization temperature was 80 ° C. and the amount of 1-butene was 4 ml. The polymer yield of the ultrahigh molecular weight ethylene copolymer thus obtained was 150 g, and the polymerization activity per 1 g of the catalyst was 29000 g / g-catalyst. The η in decalin (135 ° C.) was 11.2 dl / g, and the Mv obtained from this η was 1.95 million. The haze y as an index of transparency was 47%, and x was 0.4 mol%. Table 1 includes other values. The x and y satisfied the above mathematical expressions (2) and (3).

[Example 9]
Polymerization was carried out in the same manner as in Example 1 except that the polymerization temperature was 80 ° C. and the amount of 1-butene was 1.5 ml. The polymer yield of the ultrahigh molecular weight ethylene copolymer thus obtained was 150 g, and the polymerization activity per 1 g of the catalyst was 24000 g / g-catalyst. Η in decalin (135 ° C.) was 11.9 dl / g, and Mv determined from this η was 2.14 million. The haze y as an index of transparency was 67%, and x was 0.2 mol%. Table 1 includes other values. The x and y satisfied the above mathematical formula (1).

[Comparative Example 2]
Polymerization was performed in the same manner as in Example 2 except that 10 mg of the solid catalyst [C] was used instead of the solid catalyst component [A] in Example 2. The polymer yield of the ultrahigh molecular weight ethylene copolymer was 300 g, and the polymerization activity per 1 g of the catalyst was 30000 g / g-catalyst. The η in decalin (135 ° C.) was 12.0 dl / g, and the Mv determined from this η was 2.2 million. The haze as an index of transparency was 74%, and x was 0.6 mol%. Table 1 includes other values. The x and y did not satisfy the above formula (2).

[Comparative Example 3]
Polymerization was carried out in the same manner as in Example 3 except that 10 mg of the solid catalyst [C] was used instead of the solid catalyst component [A] in Example 3. The polymer yield of the ultrahigh molecular weight ethylene copolymer thus obtained was 300 g, and the polymerization activity per 1 g of the catalyst was 30000 g / g-catalyst. The η in decalin (135 ° C.) was 10.0 dl / g, and the Mv determined from this η was 1.65 million. The haze as an index of transparency was 73%, and x was 0.8 mol%. Table 1 includes other values. The x and y did not satisfy the above formula (2).

[Comparative Example 4]
Polymerization was carried out in the same manner as in Example 1 except that 1-butene was not used. The polymer yield of the ultrahigh molecular weight ethylene homopolymer thus obtained was 110 g, and the polymerization activity per 1 g of the catalyst was 11000 g / g-catalyst. Η in decalin (135 ° C.) was 17.1 dl / g, and Mv obtained from this η was 3.7 million. The haze as an index of transparency was 88%, and x was 0 mol%. Table 1 includes other values.

[Comparative Example 5]
Polymerization was carried out in the same manner as in Comparative Example 1 except that 1-butene was not used. The polymer yield of the ultrahigh molecular weight ethylene homopolymer thus obtained was 170 g, and the polymerization activity per 1 g of the catalyst was 17000 g / g-catalyst. Η in decalin (135 ° C.) was 15.3 dl / g, and Mv obtained from this η was 3.1 million. The haze as an index of transparency was 88%, and x was 0 mol%. Table 1 includes other values.

[Comparative Example 6]
Polymerization was conducted in the same manner as in Example 9 except that the polymerization temperature was 85 ° C. In the ultrahigh molecular weight ethylene homopolymer polymer thus obtained, a partially aggregated polymer was observed. This agglomerated polymer is expected to hinder continuous stable production. The yield was 250 g, and the polymerization activity per 1 g of the catalyst was 25000 g / g-catalyst. Η in decalin (135 ° C.) of the polymer excluding the agglomerated polymer was 10.5 dl / g, and Mv determined from this η was 1.78 million. The haze as an index of transparency was 52%, and x was 0.3 mol%. Table 1 includes other values. These x and y did not satisfy the above formula (1).

[Comparative Example 7]
Polymerization was conducted in the same manner as in Example 2 except that the polymerization temperature was 85 ° C. In the polymer of the ultrahigh molecular weight ethylene homopolymer obtained in this manner, a partially blocky polymer was observed. This bulk polymer is expected to cause problems in continuous stable production. The yield was 270 g, and the polymerization activity per 1 g of the catalyst was 17000 g / g-catalyst. Η in decalin (135 ° C.) of the polymer excluding the bulk polymer was 10.0 dl / g, and Mv obtained from this η was 1,650,000. The haze as an index of transparency was 42%, and x was 0.6 mol%. Table 1 includes other values. These x and y did not satisfy the above formula (2).

[Comparative Example 8]
Polymerization was carried out in the same manner as in Example 3 except that the polymerization temperature was 85 ° C. In the ultra high molecular weight ethylene homopolymer polymer thus obtained, many bulk polymers were observed. This bulk polymer is expected to cause problems in continuous stable production. The yield was 320 g, and the polymerization activity per 1 g of the catalyst was 32000 g / g-catalyst. Η in decalin (135 ° C.) of the polymer excluding the bulk polymer was 9.0 dl / g, and Mv determined from this η was 14.1 million. The haze as an index of transparency was 40%, and x was 0.8 mol%. Table 1 includes other values. These x and y did not satisfy the above formula (2).

  Since the ultrahigh molecular weight ethylene copolymer of the present invention is excellent in transparency and flexibility, and is excellent in wear resistance, low friction and strength, a sliding member such as a gear, a bearing member, and an artificial joint Alternatives, ski sliding surfaces, snowboard sliding surfaces, abrasives, various magnetic tape slip sheets, flexible disk liners, bulletproof materials, battery separators, various filters, foams, films, pipes, fibers, yarns , Fishing line, cutting board and the like.

Claims (3)

An ultrahigh molecular weight ethylene copolymer having a viscosity average molecular weight (Mv) of 1 million or more, obtained by copolymerizing a monomer mixture containing ethylene and an α-olefin having 3 to 8 carbon atoms. And
(1) The content of polymerized units derived from α-olefin is 0.01 mol% or more and less than 1 mol% based on the total number of polymerized units derived from ethylene and α-olefin having 3 to 8 carbon atoms. Yes,
(2) Content of polymer units derived from α-olefin {x (mol%)} and copolymer content based on total polymerized units derived from ethylene and α-olefin having 3 to 8 carbon atoms When x is in the range of 0.01 mol% or more and less than 0.4 mol%, x is 0.4 mol% or more when the relationship with the haze {y (%)} which is an index of transparency is in the range of 0.01 mol% or more and less than 0.4 mol%. An ultra high molecular weight ethylene copolymer characterized by satisfying the following mathematical formula (2) in a range of less than 1.0 mol%.
−107.5x + 87 ≦ y ≦ −43x + 89 Expression (1)
44 ≦ y ≦ 71.8... Formula (2) The ultrahigh molecular weight ethylene copolymer according to claim 1, wherein the relationship between x and y satisfies the following formula (3) when x is in a range of 0.4 mol% or more and less than 1.0 mol%. Polymer.
44 ≦ y ≦ −43x + 89 Expression (3) A carrier (A-1) prepared by reacting an organomagnesium compound soluble in an inert hydrocarbon solvent represented by the following general formula (1) with a chlorinating agent represented by the following general formula (2) A solid catalyst component produced by supporting a titanium compound (A-2) represented by the following general formula (3) and an organometallic compound (A-3) represented by the following general formula (4) [A] And an organomagnesium compound represented by the following general formula (5) or a component [B] which is an organoaluminum compound represented by the following general formula (6). The ultrahigh molecular weight ethylene copolymer according to claim 1, characterized in that:
(M ¹ ) α (Mg) β (R ¹ ) _a (R ² ) _b (OR ³ ) _c Formula (1)
(In the formula, M ¹ is a metal atom other than magnesium belonging to the group consisting of Group 1, Group 2, Group 12 and Group 13 of the Periodic Table, and R ¹ , R ² and R ³ are each independently And α, β, a, b and c are real numbers satisfying the following relationship: 0 ≦ α, 0 <β, 0 ≦ a, 0 ≦ b , 0 ≦ c, 0 <a + b, 0 ≦ c / (α + β) ≦ 2, kα + 2β = a + b + c (where k is the valence of M ¹ ))
H _d SiCl _e R ⁴ _{(4- (d + e))} (2)
(Wherein R ⁴ is a hydrocarbon group having 1 to 12 carbon atoms, and d and e are real numbers satisfying the following relationship: 0 <d, 0 <e, 0 <d + e ≦ 4)
Ti (OR ⁵ ) _f X ¹ _(4-f) Formula (3)
(In the formula, f is a real number of 0 or more and 4 or less, R ⁵ is a hydrocarbon group of 1 to 20 carbon atoms, and X ¹ is a halogen atom.)
(M ² ) γ (Mg) ε (R ⁶ ) _h (R ⁷ ) _i Y _j Expression (4)
(In the formula, M ² is a metal atom belonging to the group consisting of Group 1, Group 2, Group 12 and Group 13 of the periodic table, and R ⁶ and R ⁷ each independently represent 2 carbon atoms. 20 or less hydrocarbon group, Y is alkoxy, siloxy, allyloxy, amino, amide, —N═C—R ⁸ R ⁹ , —SR ¹⁰ (where R ⁸ , R ⁹ and R ¹⁰ are carbon atoms) Represents a hydrocarbon group of 2 or more and 20 or less), β-keto acid residues, and γ, ε, h, i and j are real numbers satisfying the following relationship: 0 ≦ γ, 0 <ε, 0 ≦ h, 0 ≦ i, 0 <h + i, 0 ≦ j / (γ + ε) ≦ 2, nγ + 2ε = h + i + j (where n is the valence of M ² ))
(M ³ ) κ (Mg) λ (R ¹¹ ) _p (R ¹² ) _q (OR ¹³ ) _r Expression (5)
(In the formula, M ³ is a metal atom belonging to the group consisting of Group 1, Group 2, Group 12 and Group 13 of the Periodic Table; R ¹¹ , R ¹² and R ¹³ are each independently It is a hydrocarbon group having 2 to 20 carbon atoms, and κ, λ, p, q and r are numbers satisfying the following relationship: 0 ≦ κ, 0 <λ, 0 ≦ p, 0 ≦ q, 0 ≦ r, 0 <p + q, 0 ≦ r / (κ + λ) ≦ 2, kκ + 2λ = p + q + r (where k is the valence of M ³ ))
AlR ¹⁴ _s X ² _3-s (6)
(Wherein, R ¹⁴ each independently represent the number 1 to 12 linear, branched or cyclic alkyl group or having 6 to 20 aryl group carbon, X ² are each independently And a halide, a hydride, or an alkoxide group having 1 to 10 carbon atoms, and s is a real number having 1 to 3 carbon atoms.)