JP6829166B2 - Polyethylene powder and its molded product - Google Patents

Description

The present invention relates to polyethylene powder and a molded product thereof.

Ultra-high molecular weight polyethylene powder is used as a raw material for a wide variety of products such as films, sheets, microporous membranes, fibers, foams, and pipes. Ultra-high molecular weight polyethylene is used in various fields as an engineering plastic having characteristics such as excellent impact resistance, wear resistance, and self-lubricating property. Since this high molecular weight polyethylene has a much higher molecular weight than general-purpose polyethylene, it is expected that a molded product having high strength and high elasticity can be obtained by highly oriented, and the high molecular weight polyethylene is highly oriented. Various studies have been made to make it.

Among the high molecular weight polyethylenes, especially the polymer with a high degree of polymerization called ultra high molecular weight polyethylene has a high molecular weight, which makes it difficult to perform molding from melt kneading, which is a general resin molding method. It is known that there is. Therefore, as a method for molding ultra-high molecular weight polyethylene, a solid phase stretch molding method has been developed in which ultra-high molecular weight polyethylene is physically pressure-bonded and stretched at a temperature below the melting point. Further, it is known that ultra-high molecular weight polyethylene for solid phase stretch molding hinders moldability due to entanglement between molecular chains generated during the polymerization, which adversely affects physical properties such as strength. Has been done. Therefore, as an ultra-high molecular weight polyethylene suitable for solid phase stretching processing, an ultra high molecular weight polyethylene having a high molecular weight and a low degree of entanglement between molecular chains has been developed.

For example, Patent Document 1 discloses a method for obtaining a molded product having high strength from ultra-high molecular weight polyethylene by a solid phase stretch molding method. More specifically, in this document, an organic metal complex ([3-t-Bu-2-O-C ₈ H ₃ CH = N (C ₆ F ₅ )] ₂ TiCl ₂ ) and aluminoxane are added to a toluene solution. In the dissolved state, polymerization is carried out in the presence of a prepared phenoxyimine (FI) catalyst to produce ultra-high molecular weight polyethylene, and the obtained ultra high molecular weight polyethylene is molded by a solid phase stretching molding method to obtain 3 GPa. It is disclosed that a sheet-type stretched molded article having the above breaking strength can be obtained.

Patent Document 2 describes a technique for designing a catalyst molecule having excellent industrial productivity (that is, control of molecular weight under high temperature polymerization conditions and suppression of excessive polymerization activity) by diligently developing a catalytic ligand structure of the FI catalyst. Is disclosed.

Non-Patent Document 1 requires a large excess of methylarmoxane (MAO) as a co-catalyst for catalyst activation during polymerization with respect to metallocene catalysts and post-metallocene catalysts, so-called single-site catalysts, transition metal molecular species. In addition, the trimethylaluminum contained in the production of this MAO forms a catalytically inactive Me-bridged dinuclear molecular species with the transition metal complex, and promotes the formation of an oligomeric polymer. Problems such as the catalyst are disclosed. In response to such problems, Non-Patent Document 1 describes by adding an appropriate amount of steric shielding phenol such as 2,6-di-t-butylphenol or its 4-Me-substituted homologue to MAO. A technique for improving the performance as a single-site catalyst is disclosed.

However, in the above-mentioned catalyst form of high molecular weight polyethylene suitable for solid phase stretching, that is, a polymerization method using a so-called homogeneous catalyst, a phenomenon in which a polymer adheres to a polymerization tank wall or a stirring blade during a polymerization reaction, so-called fouling, occurs. There is a problem that the shape and size of the obtained high molecular weight polyethylene are inhomogeneous and huge lumps such as lumps and fibers. For this reason, industrially stable production is extremely difficult with the methods for producing ethylene-based polymers described in Patent Documents 1 and 2 and Non-Patent Document 1.

Generally, when an olefin polymer is industrially produced using a single-site catalyst, the above-mentioned fouling in suspension polymerization or vapor phase polymerization is performed by using a supported catalyst in which aluminoxane is fixed to a solid inorganic substance such as silica. The problem is solved. That is, research and development of supported catalysts are widely carried out in order to produce industrial polymers using single-site catalysts.

For example, in Patent Document 3, a supported catalyst made of solid aluminoxane having a specific structure minimizes fouling of ultra-high molecular weight polyethylene produced by polymerization to a polymerization tank wall, a stirring blade, or the like, and is even higher. Developments exhibiting polymerization activity are disclosed.

In the solid phase stretching process, it is necessary to achieve a very peculiar crimping state of polyethylene, which completely eliminates the interface between polyethylenes without melting, in addition to the industrial productive problem of fouling. Therefore, for example, Patent Document 4 describes the surface shape and particle size of the obtained ultra-high molecular weight polyethylene in view of not only suppressing fouling but also increasing the contact points and contact areas when the particles come into contact with each other. A technique for polymerizing polyethylene suitable for solid phase stretching by miniaturization of the above is disclosed.

Japanese Patent No. 5511081 Special Table 2016-522844 Japanese Patent No. 5787674 Japanese Patent No. 5750212 Journal of the American Chemical Society 2003 125 12402-12403

In the solid phase stretching process, strength is developed by compressing and stretching ultra-high molecular weight polyethylene. The ideal structure of the molded product is that all the polyethylene chains are fully stretched and super-stretched until they have a chain crystal structure. Finally, a stretched sheet having a stretching ratio of several hundred times and a thickness of several μm is desired as an industrial molded product by processing below the melting point. The supported carrier catalysts of Patent Documents 3 and 4 are effective in fouling for industrial polyethylene production and eliminating interparticle crimping defects during compression processing in the initial stage of solid phase stretching, and have some effect. This is a technology that also contributes to improving the stretchability of polyethylene. However, the carrier particles of the catalyst not only serve as a starting point for causing the strength of the molded product and breaking during the stretching process, but also impurities in the molded product, so-called fish eye, for stretching at an ultra-high magnification of several hundred times. As a result, it causes uniform defects such as sheet thickness, and has a big problem in terms of strength and product stability.

Therefore, an object of the present invention is to provide a polyethylene powder having excellent fluidity, moldability during solid phase stretch molding (particularly during compression processing), and appearance when formed into a molded product, and a molded product thereof. ..

As a result of diligent research to solve the above problems, the present inventor has conducted intensive research, and found that the viscosity average molecular weight, the amount of heat absorbed by melting under predetermined conditions, the proportion of particles having a particle size within a predetermined range, and the particle size within a predetermined range. We have found that polyethylene powders having particles having a hardness within a specific range can solve the above problems, and have completed the present invention.

That is, the present invention is as follows.
[1]
A polyethylene powder having the following characteristics (1) to (4).
(1) The viscosity average molecular weight is 1 million or more and 15 million or less. (2) In the polyethylene powder after giving a heat history at 110 ° C. for 6 hours under a reduced pressure environment of 0.1 to 0.5 kPa. The melting heat absorption amount ΔH measured by the differential scanning calorific value analysis is 230 J / g or more and 293 J / g or less. (3) The proportion of particles having a particle diameter of 425 μm or more in the polyethylene powder is 10% by mass or more and 80. Mass% or less (4) In the crushing strength test of particles having a particle size of 300 μm or more and 1180 μm or less in the polyethylene powder, when the particle size of the particles is displaced to 40% of the particle size at the start of measurement. Load The load is 2.0N or more and 9.0N or less [2]
The polyethylene powder of [1] further having the following property (5).
(5) In the polyethylene powder, the circularity obtained by image analysis of particles having a particle diameter of 300 μm or more and 1180 μm or less is 95% or more [3].
The polyethylene powder of [1] or [2] further having the following property (6).
(6) The total content of Si, Mg, Ti, Zr, and Hf in the polyethylene powder by inductively coupled plasma mass spectrometry (ICP / MS) is 20 mass ppm or less [4].
A molded product containing the polyethylene powder according to any one of [1] to [3] as a component.
[5]
The molded product of [4], which is a solid phase stretched fiber.

According to the present invention, it is possible to provide a polyethylene powder having excellent fluidity, moldability during solid phase stretch molding (particularly during compression processing), and appearance when formed into a molded product, and a molded product thereof.

It is explanatory drawing for demonstrating the circularity ratio of a particle.

Hereinafter, embodiments for carrying out the present invention (hereinafter, referred to as “the present embodiment”) will be described in detail. The following embodiments are examples for explaining the present invention, and are not intended to limit the present invention to the following contents. The present invention can be appropriately modified and carried out within the scope of the gist thereof.

The polyethylene powder of this embodiment has the following properties (1) to (4). The polyethylene powder of the present embodiment has the following characteristics (1) to (4), so that it has fluidity, moldability during solid phase stretch molding (particularly during compression processing), and appearance when formed into a molded product. Excellent.
(1) The viscosity average molecular weight is 1 million or more and 15 million or less. (2) In the polyethylene powder after giving a heat history at 110 ° C. for 6 hours under a reduced pressure environment of 0.1 to 0.5 kPa. The melting heat absorption amount ΔH measured by the differential scanning calorific value analysis is 230 J / g or more and 293 J / g or less. (3) The proportion of particles having a particle diameter of 425 μm or more in the polyethylene powder is 10% by mass or more and 80 mass. % Or less (4) Load when the particle size of the particles is displaced to 40% of the particle size at the start of measurement in the crushing strength test of the particles having a particle size of 300 μm or more and 1180 μm or less in the polyethylene powder. The load is 2N or more and 9N or less

The polyethylene powder of the present embodiment (hereinafter, also referred to as "ethylene polymer", "powder", or "particle") is a powder composed of a polymer in which 99.5 mol% or more of the repeating unit is made of ethylene. The polyethylene powder is not particularly limited, and examples thereof include an ethylene homopolymer and a copolymer of ethylene and one or more other comonomer (for example, a binary or ternary copolymer). When the polyethylene powder is a copolymer, the amount of other comonomer in the copolymer can be measured by, for example, NMR.

The comonomer is not limited to the following, and examples thereof include α-olefins and vinyl compounds. The α-olefin is not particularly limited, and examples thereof include α-olefins having 3 to 20 carbon atoms, and more specifically, propylene, 1-butene, 4-methyl-1-pentene, 1-hexene, and the like. Examples thereof include 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene and 1-tetradecene. Among these, propylene and 1-butene are preferable from the viewpoint of heat resistance and strength of the molded product. One type of comonomer may be used alone, or two or more types may be used in combination.

[Viscosity average molecular weight (Mv)]
The viscosity average molecular weight (Mv) of the polyethylene powder of the present embodiment is 1 million or more and 15 million or less, preferably 1.5 million or more and 10 million or less, and more preferably 2 million or more and 7 million or less. The viscosity average molecular weight (Mv) of this embodiment can be measured by the method described in Examples described later.

When the viscosity average molecular weight is within the above range, the molded product has excellent strength, while the entanglement of the polymer chains is suppressed within an appropriate range, so that good molding processability can be realized.

In the present embodiment, as a method of controlling the viscosity average molecular weight (Mv) within the above range, for example, changing the polymerization temperature of the reactor when polymerizing ethylene and other comonomer as necessary can be mentioned. .. In general, the higher the polymerization temperature, the lower the molecular weight tends to be, and the lower the polymerization temperature, the higher the molecular weight tends to be. Further, as another method for controlling the viscosity average molecular weight (Mv) within the above range, for example, adding a chain transfer agent such as hydrogen or alkylaluminum when polymerizing ethylene or the like can be mentioned. By adding a chain transfer agent, the molecular weight of the ethylene polymer produced even at the same polymerization temperature tends to decrease. Further, as another method of controlling the viscosity average molecular weight (Mv) within the above range, changing the polymerization solvent can be mentioned. There is a tendency that a high molecular weight ethylene polymer can be obtained by increasing the compatibility between the polymerization solvent and the obtained ethylene polymer. This is because, in a solvent having high compatibility, the solvent invades and diffuses into the solidified polymer relatively easily, and the diffusion of the monomer in the solvent is promoted, so that the concentration of the dissolved monomer inside the polymer also increases. As a result, the degree of polymerization of ethylene is increased, and a high molecular weight ethylene polymer tends to be obtained.

[Melting heat absorption by differential scanning calorimeter (DSC)]
The ethylene polymer of the present embodiment is measured by a differential scanning calorimeter (DSC) in polyethylene powder after being subjected to a heat history of 110 ° C. for 6 hours under a reduced pressure environment of 0.1 to 0.5 kPa. The first melting heat absorption amount (ΔH) is 230 or more and 293 J / g or less. It is preferably 235 or more and 293 J / g or less, and more preferably 240 or more and 293 J / g or less. The details of the measurement will be described later in the examples, but the above-mentioned melting heat absorption amount is a value measured by Perkin Elmer Pilis1 DSC.

Since the ethylene polymer of the present embodiment has a melting heat absorption amount within the above range, uneven stretching is suppressed, the uniformity of mechanical strength is improved, and good moldability and high strength are realized. Suitable for phase stretch molding. This is considered to be due to the following reasons. However, for this reason, the present invention is not limited in any way. That is, in solid phase stretch molding, since the ethylene polymer is molded at a temperature equal to or lower than the melting point, the higher-order structure of the ethylene polymer controls the moldability. That is, low entanglement between molecules is a major factor controlling moldability. The ethylene polymer having low molecular chain entanglement has few amorphous parts in which an entangled structure exists and many crystal parts, that is, it has a high melting heat absorption amount as in the above range. As a result, there are few entangled structures at a high draw ratio, and stretching becomes easy. Further, since the number of defects is reduced, uneven stretching is suppressed, the uniformity of mechanical strength is improved, and good moldability and high strength are realized.

In the present embodiment, as a method of controlling the heat absorption amount for melting within the above range, for example, the catalyst is dissolved and sufficiently uniformly dispersed in the polymerization solvent. It is believed that this allows the catalytically activated sites to be sufficiently distant from each other to prevent substantial polymer entanglement during polymer formation.

[Particle size distribution]
In the polyethylene powder of the present embodiment, the proportion of particles having a particle diameter of 425 μm or more is 10% by mass or more and 80% by mass or less, preferably 12.5% by mass or more and 50% by mass or less, and more preferably. It is 15% by mass or more and 30% by mass or less. The particle size distribution of this embodiment can be measured by the method described in Examples described later.

When the proportion of particles having a particle size of 425 μm or more in the polyethylene powder of the present embodiment is 10% by mass or more, the fluidity and handleability are improved. The reason for this is considered as follows, but the present invention is not limited to this reason. That is, when the fine particle polyethylene powder is electrostatically adhered or the like, the polyethylene powder having a particle diameter of 425 μm or more is contained in an amount of 10% by mass or more, so that the polyethylene powder is interlocked and flows without staying. The property is sufficiently high, and the handling property is improved by suppressing the bridge such as the injection into the hopper and the weighing from the hopper. Further, when the particles are leveled for crimping the particles, it is better that the proportion of particles having a particle diameter of 425 μm or more is 10% by mass or more, rather than the fine particles having the same particle size being uniformly stacked. The filling is densely spread. In addition, when particles with different particle diameters (sizes) form a three-dimensionally discontinuous interface, that is, when the contacts of the particles are connected, tangents and tangent surfaces with periodicity over a wide range are not formed, so compression is performed. Since the particles are fixed to the pressure load during pressing and are difficult to deform or move, they tend to propagate efficiently to all particles without the concentration or force of the press being distorted.

Further, since the particles having a size of 425 μm or more are 80% by mass or less, a good compression step can be maintained, so that the molding processability in the compression step is excellent. The reason for this is considered as follows, but the present invention is not limited to this reason. That is, since the proportion of particles having a particle diameter of 425 μm or more is 80% by mass or less, when the polyethylene powder is spread and the particles are pressure-bonded to each other, the voids between the particles per unit volume increase, and the particles are filled. Since the rate is lowered, it is possible to prevent processing problems such as poor crimping of the compressed sheet and residual particle interface, so that a good compression process can be maintained.

In the present embodiment, the particle size distribution can be controlled, for example, by using a mixed solvent of a hydrocarbon and an aromatic hydrocarbon of the polymerization solvent to be used, or by the stirring ability during polymerization, that is, the number of rotations. It can also be controlled by the amount of co-catalyst with respect to the catalyst when the catalyst is activated. Although the clear causal relationship between the particle size distribution and the control factors is not clear, the dispersed state of the active species consisting of the catalyst and the co-catalyst, and the catalyst, co-catalyst, and oligomer at the stage where the polymerization proceeds and solidifies and precipitates as a polymer in the solvent. It is presumed that the aggregated state is determined by the number of revolutions and the ratio of the amount of catalyst to co-catalyst.

[Particle hardness]
In the crushing strength test of particles having a particle size of 300 μm or more and 1180 μm or less in the polyethylene powder of the present embodiment, a load is applied when the particle size of the particles is displaced to 40% of the particle size at the start of measurement (hereinafter, “” The load load at the time of 40% displacement ”is 2.0 N or more and 9.0 N or less, preferably 2.5 N or more and 8.5 N or less, and more preferably 3.0 N or more and 8.0 N or less. is there. The load of the polyethylene powder of the present embodiment in a constant displacement state can be measured by a crushing strength measuring device, and can be obtained by the method described in Examples described later.

When the load load at the time of 40% displacement is 2.0 N or more and 9.0 or less, not only the particle crimping becomes uniform, but also the time required for the crimping tends to be shortened, and the molding processability is excellent. The deformation load of polyethylene powder can be regarded as an index showing the hardness of the powder. If the load of the powder is less than 2.0 N, that is, it is too soft, the force will not be efficiently propagated to the small particle size powder filled in the voids even if the large particle size powder is deformed during compression processing. .. Since the small particle size is deformed and statically buried in the large particle size that is deformed due to the softness of the large particle size, uneven rolling and a state in which the interface does not disappear tend to occur. On the other hand, when the load is larger than 9.0 N, that is, when the hardness of the large particle size powder is too high, the elastic recovery of the powder is large and the progress of interparticle crimping is slowed down during crimping deformation below the melting point. Therefore, the particle interface tends to remain on the surface without disappearing, making it difficult to use as a drawing raw material.

Examples of the method of controlling the load at the time of 40% displacement of the polyethylene powder within the above range include a method of activating the catalyst. Specifically, it is preferable to use modified methylarmoxane (MMAO) in which an isobutyl group and a methyl group are ligands to aluminum as a co-catalyst, and further 2,6-di-t-butylphenol or 4-Me-substitution thereof. The co-catalyst may be modified by adding a three-dimensional shielding phenol such as an homologue. Although the clear theory of the causal relationship between polymer hardness and control factors is not clear, the trap of trialkylaluminum coexisting with the co-catalyst modified methylarmoxane in the reaction with a specific co-catalyst and additive phenol structure compound. It is considered that the modified methylarmoxane itself and the specific co-catalyst molecule obtained from the alkyl exchange of the phenol structure processed product have a function of controlling the higher-order structure of the polymer during polymerization. The polymerized polymer obtained by the catalytic activation of the co-catalyst is low in entanglement, and the single crystal growth of the molecular chain is promoted, so that the amorphous region between the crystal portions becomes a sparse structure, which is a macro of polyethylene powder. It is estimated that the hardness changes.

[Circular ratio]
The polyethylene powder of the present embodiment has a circularity of 95% or more, preferably 96%, more preferably 97%, which is obtained by image analysis of particles having a particle size of 300 μm or more and 1180 μm or less in the polyethylene powder. is there. The circularity of the present embodiment can be measured by the method described in Examples described later.

If the circularity is 100%, it means that the two-dimensional projection of the particles is a perfect circle. A circularity of 95% or more has the effect of improving fluidity, and when the particles are compressed, the force is dispersed 360 ° omnidirectionally in the particle compression plane, and the escape route of the spatial polymer is reduced. , It is presumed that the crimping progress is achieved evenly with other particles. However, this guess does not limit the present invention in any way.

As a method for controlling the circularity of the particles within the range of the present embodiment, the composition of the solvent during the polymerization and the concentration of the catalyst are controlled, the amount of the co-catalyst methylarmoxane modifier phenol structure compound added, and the catalyst. It is mentioned to control the addition method of. In particular, it is preferable that the position of the discharge port of the catalyst feed pipe is provided in the gas phase close to the solvent liquid surface in the polymerization reactor. When the solvent containing the catalyst is ejected from the gas phase into the polymerizer, minute spherical droplets are formed in a very short time in which the gas phase exists. This is because it reacts with vapor phase ethylene before entering the liquid phase and the initial polymerization is started, so that a true spherical polyethylene powder that follows the spherical shape of the droplet is easily produced.

[Total content of Si, Mg, Ti, Zr, and Hf]
The total content of the polyethylene powders Si, Mg, Ti, Zr, and Hf of the present embodiment is 20 mass ppm or less, preferably 15 mass ppm or less, more preferably 10 mass ppm or less, and less is preferable. .. When the total content of Si, Mg, Ti, Zr, and Hf of the polyethylene powder is within the above range, the generation of gel due to thermal deterioration of polyethylene is suppressed, and the amount of low molecular weight components generated by thermal deterioration is also reduced. Inorganic particles composed of these elements tend to be impurities and fish eyes in the stretched molded product, which may be a starting point of stretching inhibition of the molded product, or may be a drawback of poor strength.

As a method for controlling the total content of Si, Mg, Ti, Zr, and Hf of the polyethylene powder, a highly active catalyst is used, or a homogeneous catalyst that does not require an inorganic compound as a carrier is used. This includes deactivating the catalyst after separating the solvent as much as possible by the centrifugation method.

The polyethylene powder of the present embodiment may contain a neutralizing agent and an antioxidant additive.

The neutralizing agent functions as a supplement for chlorine and the like contained in the polyethylene powder, a molding processing aid, and the like. The neutralizing agent is not limited to the following, and examples thereof include stearates of alkaline earth metals such as calcium, magnesium, and barium. The content of the neutralizing agent is not particularly limited, but is preferably 5000 mass ppm or less, more preferably 4000 mass ppm or less, and further preferably 3000 mass ppm or less. In the polyethylene powder obtained by the slurry polymerization method using a metallocene catalyst, it is possible to exclude the halogen component from the catalyst constituents without using a neutralizing agent.

Antioxidants are not limited to the following, but for example, dibutylhydroxytoluene, pentaerythyl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], octadecyl-3. Phenolic compounds such as − (3,5-di-t-butyl-4-hydroxyphenyl) propionate can be mentioned. The content of the antioxidant is not particularly limited, but is preferably 5000 mass ppm or less, more preferably 4000 mass ppm or less, and further preferably 3000 mass ppm or less.

The content of the additive in the polyethylene powder can be determined, for example, by extracting for 6 hours by Soxhlet extraction using tetrahydrofuran (THF) and separating and quantifying the extract by liquid chromatography.

[Catalyst synthesis (activation)]
In the ethylene polymerization method according to the present embodiment, ethylene composed of a cocatalyst (D) formed by mixing a transition metal compound (hereinafter A), an organoaluminum oxy compound (hereinafter B) and a compound having a phenol structure (hereinafter C). It is preferable that a polymerization catalyst (liquid catalyst) is used.

[Transition metal compound A]
As the transition metal compound (A), a transition metal compound conventionally used for polymerization of olefins is used without limitation, but preferably, a periodic table 4 containing a ligand having a cyclopentadienyl skeleton shown below is used. Group transition metal compounds (I-1) to (I-4) or transition metal compounds (II) having a cyclic η-binding anion ligand, and the compound of (I-2) is particularly preferably used.

The transition metal compound (A) of Group 4 of the periodic table containing a ligand having a cyclopentadienyl skeleton is a transition metal compound represented by the following general formula (I-1).

M1Lx ... (I-1)
In the formula, M1 represents a transition metal atom selected from Group 4 of the periodic table, specifically zirconium, titanium or hafnium, preferably titanium. x is a number that satisfies the valence of the transition metal atom M1 and indicates the number of ligands L that coordinate with the transition metal atom M1. L indicates a ligand coordinated to a transition metal atom, at least one L is a ligand having a cyclopentadienyl skeleton, and L other than the ligand having a cyclopentadienyl skeleton is carbon. It is a hydrocarbon group having 1 to 20 atoms, a halogenated hydrocarbon group having 1 to 20 carbon atoms, an oxygen-containing group, a sulfur-containing group, a silicon-containing group, a halogen atom or a hydrogen atom.

Examples of the ligand having a cyclopentadienyl skeleton include a cyclopentadienyl group, a methylcyclopentadienyl group, a dimethylcyclopentadienyl group, a trimethylcyclopentadienyl group, a tetramethylcyclopentadienyl group, and a penta. Methylcyclopentadienyl group, ethylcyclopentadienyl group, methylethylcyclopentadienyl group, propylcyclopentadienyl group, methylpropylcyclopentadienyl group, butylcyclopentadienyl group, methylbutylcyclopentadienyl group Examples thereof include an alkyl-substituted cyclopentadienyl group such as a group and a hexylcyclopentadienyl group or an indenyl group, a 4,5,6,7-tetrahydroindenyl group, a fluorenyl group and the like. These groups may be substituted with (halogenated) hydrocarbon groups having 1 to 20 carbon atoms, oxygen-containing groups, sulfur-containing groups, silicon-containing groups, halogen atoms and the like.

When the compound represented by the above general formula (I-1) contains two or more ligands having a cyclopentadienyl skeleton, the ligands having two cyclopentadienyl skeletons are (1). It may be bonded via a divalent bonding group such as a (substituted) alkylene group or a (substituted) silylene group. A transition metal compound in which such a ligand having two cyclopentadienyl skeletons is bonded via a divalent bonding group is a transition represented by the general formula (I-3) as described later. Metal compounds can be mentioned.

Specific examples of the ligand L other than the ligand having a cyclopentadienyl skeleton include the following. Examples of the hydrocarbon group having 1 to 20 carbon atoms include an alkyl group, a cycloalkyl group, an alkenyl group, an arylalkyl group, and an aryl group, and more specifically, methyl, ethyl, propyl, butyl, and hexyl. , Alkyl groups such as octyl, nonyl, dodecyl, aicosyl; cycloalkyl groups such as cyclopentyl, cyclohexyl, norbornyl, adamantyl; alkyl groups such as vinyl, propenyl, cyclohexenyl; arylalkyl groups such as benzyl, phenylethyl, phenylpropyl; Aryl groups such as phenyl, trill, dimethylphenyl, trimethylphenyl, ethylphenyl, propylphenyl, biphenylyl, naphthyl, methylnaphthyl, anthryl, and phenanthryl can be mentioned.

Examples of the halogenated hydrocarbon group having 1 to 20 carbon atoms include a group in which the hydrocarbon group having 1 to 20 carbon atoms is substituted with halogen. Specific examples of the oxygen-containing group include a hydroxy group; an alkoxy group such as a methoxy group, an ethoxy group, a propoxy group, and a butoxy group; an aryloxy group such as a phenoxy group, a methylphenoxy group, a dimethylphenoxy group, and a naphthoxy group; a phenylmethoxy group. , Arylalkoxy groups such as phenylethoxy group and the like.

Specifically, as the sulfur-containing group, a substituent in which the oxygen of the oxygen-containing group is replaced with sulfur, a methyl sulphonate group, a trifluoromethane sulphonate group, a phenyl sulphonate group, a benzyl sulphonate group, p. -Sulfonate groups such as toluene sulphonate group, trimethylbenzene sulphonate group, triisobutylbenzene sulphonate group, p-chlorobenzene sulphonate group, pentafluorobenzene sulphonate group; methyl sulphonate group, phenyl Examples thereof include a sulfinate group such as a sulfinate group, a benzyl sulfinate group, a p-toluene sulfinate group, a trimethylbenzene sulfinate group and a pentafluorobenzene sulfinate group.

Specifically, the silicon-containing group is a monohydrocarbon-substituted silyl group such as a methylsilyl group or a phenylsilyl group; a dihydrocarbon-substituted silyl group such as a dimethylsilyl group or a diphenylsilyl group; a trimethylsilyl group, a triethylsilyl group, or a tripropylsilyl. Tricarbophilic substituted silyl group such as group, tricyclohexylsilyl group, triphenylsilyl group, dimethylphenylsilyl group, methyldiphenylsilyl group, tritrylsilyl group, trinaphthylsilyl group; silyl of hydrocarbon substituted silyl such as trimethylsilyl ether Examples thereof include ether; a silicon-substituted alkyl group such as a trimethylsilylmethyl group; and a silicon-substituted aryl group such as a trimethylsilylphenyl group.

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. Such a transition metal compound is more specifically represented by the following general formula (I-2) when, for example, the valence of the transition metal is 4.

R ₁ R ₂ R ₃ R ₄ M ₁ … (I-2)
In the formula, M ₁ represents a transition metal atom selected from Group 4 of the periodic table similar to the above, and is preferably a titanium atom.
R ₁ indicates a group (ligand) having a cyclopentadienyl skeleton, and R ₂ , R ₃ and R ₄ may be the same or different from each other, and a group having a cyclopentadienyl skeleton (coordination). (Child), (halogenated) hydrocarbon group having 1 to 20 carbon atoms, oxygen-containing group, sulfur-containing group, silicon-containing group, halogen atom or hydrogen atom.

In the transition metal compound represented by the above formula (I-2) in the present invention, R2, at least one of R ₃ and R ₄ is a group (ligand) having a cyclopentadienyl skeleton compound, e.g. Compounds in which R ₁ and R ₂ are groups (ligands) having a cyclopentadienyl skeleton are preferably used. When R ₁ and R ₂ are groups (ligands) having a cyclopentadienyl skeleton, R ₃ and R ₄ are groups having a cyclopentadienyl skeleton, an alkyl group, a cycloalkyl group, an alkenyl group, It is preferably an arylalkyl group, an aryl group, an alkoxy group, an aryloxy group, a trialkylsilyl group, a sulfonate group, a halogen atom or a hydrogen atom.

Hereinafter, with respect to the transition metal compound represented by the general formula (I-1) in which M ₁ is zirconium, specific compounds include bis (indenyl) zirconium dichloride, bis (indenyl) zirconium dibromid, and bis ( Indenyl) Zirconium Bis (p-Toluene Sulfonate), Bis (4,5,6,7-Tetrahydroindenyl) Zirconium Dichloride, Bis (Fluorenyl) Zirconium Dichloride, Bis (Cyclopentadienyl) Zirconium Dichloride, Bis (Cyclo) Pentazienyl) zirconium dibromide, bis (cyclopentadienyl) methylzirconium monolide, bis (cyclopentadienyl) ethylzirconium monolide, bis (cyclopentadienyl) cyclohexylzirconium monolide, bis (cyclopentadienyl) ) Phenylzirconium monolide, bis (cyclopentadienyl) benzyl zirconium monohydride, bis (cyclopentadienyl) zirconium monohydride, bis (cyclopentadienyl) methylzirconium monohydride, bis (cyclopentadienyl) Dimethylzirconium, bis (cyclopentadienyl) diphenylzirconium, bis (cyclopentadienyl) dibenzylzirconium, bis (cyclopentadienyl) zirconium methoxychloride, bis (cyclopentadienyl) zirconium ethoxychloride, bis (cyclopenta) Dienyl) zirconium bis (methanesulfonate), bis (cyclopentadienyl) zirconium bis (p-toluenesulfonate), bis (cyclopentadienyl) zirconium bis (trifluoromethanesulfonate), bis (methyl) Cyclopentadienyl) zirconium dichloride, bis (dimethylcyclopentadienyl) zirconium dichloride, bis (dimethylcyclopentadienyl) zirconium ethoxychloride, bis (dimethylcyclopentadienyl) zirconium bis (trifluoromethanesulfonate), bis (Ethylcyclopentadienyl) zirconium dichloride, bis (methylethylcyclopentadienyl) zirconium dichloride, bis (propylcyclopentadienyl) zirconium dichloride, bis (methylpropylcyclopentadienyl) zirconium dichloride, bis (butylcyclopenta) Dienil) Zirconium dichlori Do, bis (methylbutylcyclopentadienyl) zirconium dichloride, bis (methylbutylcyclopentadienyl) zirconium bis (methanesulfonate), bis (trimethylcyclopentadienyl) zirconium dichloride, bis (tetramethylcyclopentadienyl) Examples thereof include enyl) zirconium dichloride, bis (pentamethylcyclopentadienyl) zirconium dichloride, bis (hexylcyclopentadienyl) zirconium dichloride, and bis (trimethylsilylcyclopentadienyl) zirconium dichloride.

In the above example, the di-substituted cyclopentadienyl ring contains 1,2- and 1,3-substituted products, and the tri-substituted product is a 1,2,3- and 1,2,4-substituted product. including. Alkyl groups such as propyl group and butyl group contain isomers such as n-, i-, sec- and tert-.

Moreover, among the zirconium compounds as described above, a compound in which zirconium is replaced with titanium or hafnium can also be mentioned. Examples of the transition metal compound in which a ligand having two cyclopentadienyl skeletons is bonded via a divalent bonding group include a compound represented by the following formula (I-3).

(I-3)

In the formula, M ² represents a transition metal atom of Group 4 of the periodic table, specifically zirconium, titanium or hafnium, preferably titanium. R ⁵ , R ⁶ , R ⁷ and R ⁸ may be the same or different from each other, and contain a hydrocarbon group having 1 to 20 carbon atoms, a halogenated hydrocarbon group having 1 to 20 carbon atoms, and oxygen. Indicates a group, a sulfur-containing group, a silicon-containing group, a nitrogen-containing group, a phosphorus-containing group, a halogen atom or a hydrogen atom. Of the groups represented by R ⁵ , R ⁶ , R ⁷ and R ⁸ , some of the groups adjacent to each other may be bonded to form a ring together with the carbon atom to which these groups are bonded. R ⁵ , R ⁶ , R ⁷ and R ⁸ are displayed in two places each, but for example, R ⁵ and R ⁵ may be the same group or different groups, respectively. The groups represented by R with the same reference numerals indicate a preferable combination in the case of connecting them to form a ring.

Examples of the hydrocarbon group having 1 to 20 carbon atoms include an alkyl group, a cycloalkyl group, an alkenyl group, an arylalkyl group, and an aryl group similar to those in L.

Rings formed by combining these hydrocarbon groups include condensed ring groups such as a benzene ring, a naphthalene ring, an acenaphthene ring, and an inden ring, and the hydrogen atom on the condensed ring group is methyl, ethyl, propyl, butyl, or the like. Examples include groups substituted with alkyl groups.

Examples of the halogenated hydrocarbon group having 1 to 20 carbon atoms include a group in which the hydrocarbon group having 1 to 20 carbon atoms is substituted with halogen. Examples of the oxygen-containing group include a hydroxy group and an alkoxy group similar to the above L, an aryloxy group, an arylalkoxy group and the like.

Examples of the sulfur-containing group include a substituent in which the oxygen of the oxygen-containing group is replaced with sulfur. Examples of the silicon-containing group include the same monohydrocarbon-substituted silyl group, di-hydrocarbon-substituted silyl group, tri-hydrocarbon-substituted silyl group, hydrocarbon-substituted silyl group silyl ether, silicon-substituted alkyl group, and silicon-substituted aryl group as in L. And so on.

Nitrogen-containing groups include amino groups; methylamino groups, dimethylamino groups, diethylamino groups, dipropylamino groups, dibutylamino groups, dicyclohexylamino groups and other alkylamino groups; phenylamino groups, diphenylamino groups, ditrilamino groups, dinaphthyl. Examples thereof include an arylamino group such as an amino group and a methylphenylamino group, or an alkylarylamino group.

Examples of the phosphorus-containing group include a phosphosphino group such as a dimethylphosphino group and a diphenylphosphino group. Examples of the halogen atom include those similar to L.

Of these, hydrocarbon groups having 1 to 20 carbon atoms or hydrogen atoms are preferable, and in particular, hydrocarbon groups and hydrocarbons having 1 to 4 carbon atoms such as methyl group, ethyl group, propyl group and butyl group. The hydrogen atoms on the benzene ring formed by bonding groups and the benzene ring formed by bonding hydrocarbon groups are methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso. -It is preferable that the group is substituted with an alkyl group such as a butyl group or a tert-butyl group.

X ¹ and X ² may be the same or different from each other, and may contain 1 to 20 carbon atoms, a halogenated hydrocarbon group having 1 to 20 carbon atoms, an oxygen-containing group, a sulfur-containing group, and a silicon-containing group. Indicates a group, hydrogen atom, or halogen atom.

Examples of the hydrocarbon group having 1 to 20 carbon atoms include an alkyl group, a cycloalkyl group, an alkenyl group, an arylalkyl group, and an aryl group similar to those in L.

Examples of the halogenated hydrocarbon group having 1 to 20 carbon atoms include a group in which the hydrocarbon group having 1 to 20 carbon atoms is substituted with halogen. Examples of the oxygen-containing group include a hydroxy group and an alkoxy group similar to L, an aryloxy group, an arylalkoxy group and the like.

Examples of the sulfur-containing group include a substituent in which the oxygen of the oxygen-containing group is replaced with sulfur, a sulfonate group similar to that of L, a sulfinate group, and the like. Examples of the silicon-containing group include a silicon-substituted alkyl group and a silicon-substituted aryl group similar to L.

Examples of the halogen atom include the same group and atom as L. Of these, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, or a sulfonate group is preferable.

Y ¹ is a divalent hydrocarbon group having 1 to 20 carbon atoms, a divalent halogenated hydrocarbon group having 1 to 20 carbon atoms, a divalent silicon-containing group, and a divalent germanium-containing group. divalent tin-containing group, -O -, - CO -, - S -, - SO -, - SO2 -, - Ge -, - Sn -, - NR 9 -, - P (R 9) -, - P ^{(O) (R 9) -} , - BR 9 - or -AlR ⁹ - (provided that, R ⁹ may be the same or different and are each a hydrocarbon group having 1 to 20 carbon atoms, carbon atoms 1 to 20 halogenated hydrocarbon groups, hydrogen atoms or halogen atoms).

Specific examples of the divalent hydrocarbon group having 1 to 20 carbon atoms include a methylene group, a dimethylmethylene group, a 1,2-ethylene group, a dimethyl-1,2-ethylene group, and a 1,3-trimethylene group. Alkylene groups such as 1,4-tetramethylene group, 1,2-cyclohexylene group and 1,4-cyclohexylene group; arylalkylene groups such as diphenylmethylene group and diphenyl-1,2-ethylene group can be mentioned.

Specific examples of the divalent halogenated hydrocarbon group having 1 to 20 carbon atoms include a halogenated group of the divalent hydrocarbon group having 1 to 20 carbon atoms such as chloromethylene. ..

The divalent silicon-containing group includes a silylene group, a methyl silylene group, a dimethyl silylene group, a diethyl silylene group, a di (n-propyl) silylene group, a di (i-propyl) silylene group, a di (cyclohexyl) silylene group, and a methyl. Alkyl silylene groups such as phenyl silylene group, diphenyl silylene group, di (p-tolyl) silylene group, di (p-chlorophenyl) silylene group; alkylaryl silylene group; aryl silylene group; tetramethyl-1,2-disylylene group, Examples thereof include an alkyl disylylene group such as a tetraphenyl-1,2-disylylene group; an alkylaryl disylylene group; and an aryl disylylene group.

Examples of the divalent germanium-containing group include a group in which the silicon of the divalent silicon-containing group is replaced with germanium. Examples of the divalent tin-containing group include a group in which the silicon of the divalent silicon-containing group is replaced with tin.

Further, R ⁹ is a hydrocarbon group having 1 to 20 carbon atoms and a halogenated hydrocarbon group having 1 to 20 carbon atoms or a halogen atom similar to the above L. Of these, a substituted silylene group such as a dimethyl silylene group, a diphenyl silylene group, or a methylphenyl silylene group is particularly preferable.

Hereinafter, as the specific compound for the transition metal compound represented by the general formula (I-3), ethylene-bis (indenyl) dimethylzirconium,
Ethylene-bis (indenyl) zirconium dichloride, ethylene-bis (indenyl) zirconium bis (trifluoromethanesulfonate), ethylene-bis (indenyl) zirconium bis (methanesulfonate), ethylene-bis (indenyl) zirconium bis (p) -Toluene sulfonate), ethylene-bis (indenyl) zirconium bis (p-chlorobenzene sulfonate), ethylene-bis (4,5,6,7-tetrahydroindenyl) zirconium dichloride, isopropylidene-bis (cyclo) Pentazienyl) (fluorenyl) zirconium dichloride, isopropylidene-bis (cyclopentadienyl) (methylcyclopentadienyl) zirconium dichloride, dimethylsilylene-bis (cyclopentadienyl) zirconium dichloride, dimethylsilylene-bis (methylcyclo) Pentazienyl) zirconium dichloride, dimethylsilylene-bis (dimethylcyclopentadienyl) zirconium dichloride, dimethylsilylene-bis (trimethylcyclopentadienyl) zirconium dichloride, dimethylsilylene-bis (indenyl) zirconium dichloride, dimethylsilylene-bis Indenyl) Zirconium bis (trifluoromethanesulfonate), dimethylsilylene-bis (4,5,6,7-tetrahydroindenyl) zirconium dichloride, dimethylsilylene-bis (cyclopentadienyl) (fluorenyl) zirconium dichloride, diphenylcilylene -Bis (indenyl) zirconium dichloride, methylphenylcilylene-bis (indenyl) zirconium dichloride, rac-dimethylsilylene-bis (2,3,5-trimethylcyclopentadienyl) zirconium dichloride, rac-dimethylsilylene-bis (2, 4,7-trimethylcyclopentadienyl) zirconium dichloride, rac-dimethylsilylene-bis (2-methyl-4-tert-butylcyclopentadienyl) zirconium dichloride, isopropylidene- (cyclopentadienyl) (fluorenyl) zirconium Dichloride, dimethylsilylene- (3-tert-butylcyclopentadienyl) (indenyl) zirconium dichloride, isopropylidene- (4-methylcyclopentadienyl) (3-methylindenyl) zirconium dichloride, isopropylidene-(4-4-) tert-Butylcyclopentadienyl) (3-methylindenyl) zirconide, isopropylidene-(4-tert-butylcyclopentadienyl) (3-tert-butylindenyl) zirconidylide, dimethylsilylene- (4-4- Methylcyclopentadienyl) (3-methylindenyl) zirconidyllide, dimethylsilylene-(4-tert-butylcyclopentadienyl) (3-methylindenyl) zirconidyllide, dimethylsilylene-(4-tert-butylcyclo) Pentazienyl) (3-tert-butylindenyl) zirconium dichloride, dimethylsilylene-(3-tert-butylcyclopentadienyl) (fluorenyl) zirconide, isopropylidene- (3-tert-butylcyclopentadienyl) Examples include (fluorenyl) zirconium dichloride.

Further, a compound in which zirconium in the above-mentioned compound is replaced with titanium or funium can be mentioned. More specifically, the transition metal compound represented by the formula (I-3) includes a transition metal compound represented by the following general formula (I-4).

In the formula, M ² represents a transition metal atom of Group 4 of the periodic table, specifically titanium, zirconium or hafnium, preferably titanium. R ¹⁰ may be the same or different from each other and represents a hydrocarbon group having 1 to 6 carbon atoms. Specifically, a methyl group, an ethyl group, an n-propyl group, an isopropyl group and an n-butyl group. , Isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, neopentyl group, n-hexyl group, cyclohexyl group and other alkyl groups; vinyl group, propenyl group and other alkenyl groups and the like.

Of these, an alkyl group having a primary carbon atom bonded to an indenyl group is preferable, an alkyl group having 1 to 4 carbon atoms is preferable, and a methyl group and an ethyl group are particularly preferable.

R ¹¹ , R ¹³ , R ¹⁴ and R ¹⁵ may be the same or different from each other and represent a hydrogen atom, a halogen atom or a hydrocarbon group having 1 to 6 carbon atoms similar to R ¹⁰ . R ¹² may be the same or different from each other and represents an aryl group having 6 to 16 hydrogen atoms or carbon atoms, specifically, a phenyl group, an α-naphthyl group, a β-naphthyl group, an anthryl group, and the like. Examples thereof include a phenanthryl group, a pyrenyl group, an acenaphthyl group, a phenylenyl group, an acetylenyl group, a tetrahydronaphthyl group, an indanyl group and a biphenylyl group. Of these, a phenyl group, a naphthyl group, an anthryl group, and a phenanthryl group are preferable.

These aryl groups are halogen atoms such as fluorine, chlorine, bromine and iodine; methyl group, ethyl group, propyl group, butyl group, hexyl group, cyclohexyl group, octyl group, nonyl group, dodecyl group, icosyl group and norbornyl group. Alkyl groups such as adamantyl group; alkenyl groups such as vinyl group, propenyl group and cyclohexenyl group; arylalkyl groups such as benzyl group, phenylethyl group and phenylpropyl group; phenyl group, trill group, dimethylphenyl group and trimethylphenyl Group, ethylphenyl group, propylphenyl group, biphenyl group, α- or β-naphthyl group, methylnaphthyl group, anthryl group, phenanthryl group, benzylphenyl group, pyrenyl group, acenaphthyl group, phenalenyl group, acetylenyl group, tetrahydro A hydrocarbon group having 1 to 20 carbon atoms such as an aryl group such as a naphthyl group, an indanyl group and a biphenylyl group; may be substituted with an organic silyl group such as a trimethylsilyl group, a triethylsilyl group and a triphenylsilyl group.

X ¹ and X ² may be the same or different, it is the same as X ¹ and X ² in the general formula I-3) in. Of these, a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms is preferable.

Y ¹ is the same as Y ¹ in the general formula (I-3). Of these, a divalent silicon-containing group is preferable, a divalent germanium-containing group is preferable, a divalent silicon-containing group is more preferable, and an alkylsilylene, an alkylarylsilylene or an arylcyrylene is more preferable. preferable.

Specific examples of the transition metal compound represented by the above general formula (I-4) are as follows: rac-dimethylsilylene-bis {1- (2-methyl-4-phenylindenyl)} zirconium dichloride, rac. -Dimethylsilylene-bis {1- (2-methyl-4- (α-naphthyl) indenyl)} Zirconium dichloride, rac-dimethylsilylene-bis {1- (2-methyl-4- (β-naphthyl) indenyl)} Zirconium dichloride, rac-dimethylsilylene-bis {1- (2-methyl-4- (1-anthryl) indenyl)} Zirconium dichloride, rac-dimethylsilylene-bis {1- (2-methyl-4- (2-anthryl) indenyl)} ) Zirconium)} Zirconium dichloride, rac-dimethylsilylene-bis {1- (2-methyl-4- (9-anthril) indenyl)} Zirconium dichloride, rac-dimethylsilylene-bis {1- (2-methyl-4-) (9-Phenantril) indenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-methyl-4- (p-fluorophenyl) indenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2) -Methyl-4- (pentafluorophenyl) indenyl)} zirconium dichloride,
rac-dimethylsilylene-bis {1- (2-methyl-4- (p-chlorophenyl) indenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-methyl-4- (m-chlorophenyl) indenyl) } Zyrosine dichloride, rac-dimethylsilylene-bis {1- (2-methyl-4- (o-chlorophenyl) indenyl)} Zyrosine dichloride, rac-dimethylsilylene-bis {1- (2-methyl-4- (o,,) p-dichlorophenyl) phenylindenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-methyl-4- (p-bromophenyl) indenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1-( 2-Methyl-4- (p-tolyl) indenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-methyl-4- (m-tolyl) indenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-Methyl-4- (o-tolyl) indenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-methyl-4- (o, o'-dimethylphenyl) -1-indenyl) ) Zylzyl dichloride, rac-dimethylsilylene-bis {1- (2-methyl-4- (p-ethylphenyl) indenyl)} Zirconid dichloride, rac-dimethylsilylene-bis {1- (2-methyl-4- (pi) -Propylphenyl) indenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-methyl-4- (p-benzylphenyl) indenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-) Methyl-4- (p-biphenyl) indenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-methyl-4- (m-biphenyl) indenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1 -(2-Methyl-4- (p-trimethylsilylenephenyl) indenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-methyl-4- (m-trimethylsilylenephenyl) indenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-phenyl-4-phenylindenyl)} zirconium dichloride, rac-diethylsilylene-bis {1- (2-methyl) Lu-4-phenylindenyl)} zirconium dichloride, rac-di- (i-propyl) silylene-bis {1- (2-methyl-4-phenylindenyl)} zirconium dichloride, rac-di- (n-butyl) ) Silylen-bis {1- (2-methyl-4-phenylindenyl)} zirconium dichloride, rac-dicyclohexylsilylene-bis {1- (2-methyl-4-phenylindenyl)} zirconium dichloride, rac-methylphenyl Silylen-bis {1- (2-methyl-4-phenylindenyl)} zirconium dichloride, rac-diphenylsilylene-bis {1- (2-methyl-4-phenylindenyl)} zirconium dichloride, rac-di (p) -Trill) silylene-bis {1- (2-methyl-4-phenylindenyl)} zirconium dichloride, rac-di (p-chlorophenyl) silylene-bis {1- (2-methyl-4-phenylindenyl)} Zyrazine dichloride, rac-methylene-bis {1- (2-methyl-4-phenylindenyl)} zirconium dichloride, rac-ethylene-bis {1- (2-methyl-4-phenylindenyl)} zirconium dichloride, rac -Dimethylgermilene-bis {1- (2-methyl-4-phenylindenyl)} zirconium dichloride, rac-dimethylstanylene-bis {1- (2-methyl-4-phenylindenyl)} zirconium dichloride, rac -Dimethylsilylene-bis {1- (2-methyl-4-phenylindenyl)} zirconium dibromid, rac-dimethylsilylene-bis {1- (2-methyl-4-phenylindenyl)} zirconium dimethyl, rac- Dimethylsilylene-bis {1- (2-methyl-4-phenylindenyl)} zirconium methyl chloride, rac-dimethylsilylene-bis {1- (2-methyl-4-phenylindenyl)} zirconium chloride SO ₂ Me, rac-dimethylsilylene-bis {1- (2-methyl-4-phenylindenyl)} zirconium chloride OSO ₂ Me, rac-dimethylsilylene-bis {1- (2-ethyl-4-phenylindenyl)} zirconium dichloride , Rac-dimethylsilylene-bis {1- (2-ethyl-4- (α-naphthyl) indenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-ethyl-4- (β-) Naftyl) indenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-ethyl-4- (2-methyl-1-naphthyl) indenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2) -Ethyl-4- (5-acenaphtyl) indenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-ethyl-4- (9-anthryl) indenyl)} zirconium dichloride, rac-dimethylsilylene-bis { 1- (2-Ethyl-4- (9-phenanthril) indenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-ethyl-4- (o-methylphenyl) indenyl)} zirconium dichloride, rac- Dimethylsilylene-bis {1- (2-ethyl-4- (m-methylphenyl) indenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-ethyl-4- (p-methylphenyl) indenyl) } Zyrosine dichloride, rac-dimethylsilylene-bis {1- (2-ethyl-4- (2,3-dimethylphenyl) indenyl)} Zyrazine dichloride, rac-dimethylsilylene-bis {1- (2-ethyl-4-) (2,4-Dimethylphenyl) indenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-ethyl-4- (2,5-dimethylphenyl) indenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-Ethyl-4- (2,4,6-trimethylphenyl) indenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-ethyl-4- (o-chlorophenyl) indenyl)} Zylzyl dichloride, rac-dimethylsilylene-bis {1- (2-ethyl-4- (m-chlorophenyl) indenyl)} Zyrazine dichloride, rac-dimethylsilylene-bis {1- (2-ethyl-4- (p-chlorophenyl) indenyl)} ) Indenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-ethyl-4- (2,3-dichlorophenyl) indenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-ethyl-) 4- (2,6-dichlorophenyl) indenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-ethyl-4- (3,5-dichlorophenyl) in Denyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-ethyl-4- (2-bromophenyl) indenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-ethyl-4-) (3-Bromophenyl) indenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-ethyl-4- (4-bromophenyl) indenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1-( 2-Ethyl-4- (4-biphenylyl) indenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-ethyl-4- (4-trimethylsilylphenyl) indenyl)} zirconium dichloride, rac-dimethylsilylene- Bis {1- (2-n-propyl-4-phenylindenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-n-propyl-4- (α-naphthyl) indenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-n-propyl-4- (β-naphthyl) indenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-n-propyl-4- (2-) Methyl-1-naphthyl) indenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-n-propyl-4- (5-acenaphtyl) indenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-n-propyl-4- (9-anthril) indenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-n-propyl-4- (9-phenanthryl) indenyl)} zirconium dichloride, rac -Dimethylsilylene-bis {1- (2-i-propyl-4-phenylindenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-i-propyl-4- (α-naphthyl) indenyl) } Zyrosine dichloride, rac-dimethylsilylene-bis {1- (2-i-propyl-4- (β-naphthyl) indenyl)} Zyrazine dichloride, rac-dimethylsilylene-bis {1- (2-i-propyl-4) -(8-Methyl-9-naphthyl) indenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-i-propyl-4- (5-acenaphthyl) indenyl)} zirconium dichloride Do, ra c-dimethylsilylene-bis {1- (2-i-propyl-4- (9-anthryl) indenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-i-propyl-4-) (9-Phenantril) indenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-s-butyl-4-phenylindenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-s -Butyl-4- (α-naphthyl) indenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-s-butyl-4- (β-naphthyl) indenyl)} zirconium dichloride, rac-dimethylsilylene- Bis {1- (2-s-Butyl-4- (2-methyl-1-naphthyl) indenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-s-butyl-4- (5-acenaphthyl) indenyl)} ) Indenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-s-butyl-4- (9-anthryl) indenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-s-) Butyl-4- (9-phenanthryl) indenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-n-pentyl-4-phenylindenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-n-Pentyl-4- (α-naphthyl) indenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-n-butyl-4-phenylindenyl)} zirconium dichloride, rac-dimethylsilylene -Bis {1- (2-n-Butyl-4- (α-naphthyl) indenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-n-butyl-4- (β-naphthyl) indenyl) } Zyrosine dichloride, rac-dimethylsilylene-bis {1- (2-n-butyl-4- (2-methyl-1-naphthyl) indenyl)} Zyrazine dichloride, rac-dimethylsilylene-bis {1- (2-n -Butyl-4- (5-acenaphtyl) indenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-n-butyl-4- (9-anthryl) indenyl)} zirconium dichloride, rac-dimethylsilylene- Bis {1- (2-n-Butyl-4 -(9-Phenantril) indenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-i-butyl-4-phenylindenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-) i-Butyl-4- (α-naphthyl) indenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-i-butyl-4- (β-naphthyl) indenyl)} zirconium dichloride, rac-dimethylsilylene -Bis {1- (2-i-butyl-4- (2-methyl-1-naphthyl) indenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-i-butyl-4- (5-) Acenaphthyl) indenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-i-butyl-4- (9-anthryl) indenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-i -Butyl-4- (9-phenanthryl) indenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-neopentyl-4-phenylindenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1-( 2-Neopentyl-4- (α-naphthyl) indenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-n-hexyl-4-phenylindenyl)} zirconium dichloride, rac-dimethylsilylene-bis { 1- (2-n-hexyl-4- (α-naphthyl) indenyl)} zirconium dichloride, rac-methylphenylcilylene-bis {1- (2-ethyl-4-phenylindenyl)} zirconium dichloride, rac-methyl Phenylsilylene-bis {1- (2-ethyl-4- (α-naphthyl) indenyl)} zirconium dichloride, rac-methylphenylcilylene-bis {1- (2-ethyl-4- (9-anthryl) indenyl)} Zirconium dichloride, rac-methylphenylcilylene-bis {1- (2-ethyl-4- (9-phenanthryl) indenyl)} Zirconium dichloride, rac-diphenylcilylene-bis {1- (2-ethyl-4-phenylindenyl) )} Zirconium dichloride, rac-diphenylcilylene-bis {1- (2-ethyl-4- (α-naphthyl) indenyl)} Zirconium dichloride, rac-diphenylcilylene-bi Su {1- (2-ethyl-4- (9-anthryl) indenyl)} zirconium dichloride, rac-diphenylsilylene-bis {1- (2-ethyl-4- (9-phenanthryl) indenyl)} zirconium dichloride,
rac-diphenylsilylene-bis {1- (2-ethyl-4- (4-biphenylyl) indenyl)} zirconium dichloride, rac-methylene-bis {1- (2-ethyl-4-phenylindenyl)} zirconium dichloride, rac-methylene-bis {1- (2-ethyl-4- (α-naphthyl) indenyl)} zirconium dichloride, rac-ethylene-bis {1- (2-ethyl-4-phenylindenyl)} zirconium dichloride, rac -Ethyl-Ethyl-bis {1- (2-ethyl-4- (α-naphthyl) indenyl)} Zirconium dichloride, rac-Ethyl-bis {1- (2-n-propyl-4- (α-naphthyl) indenyl)} Zirconium dichloride, rac-dimethylgelmill-bis {1- (2-ethyl-4-phenylindenyl)} Zirconium dichloride, rac-dimethylgelmil-bis {1- (2-ethyl-4- (α-naphthyl)) Indenyl)} zirconium dichloride, rac-dimethylgelmil-bis {1- (2-n-propyl-4-phenylindenyl)} zirconium dichloride and the like.

Further, a compound in which zirconium in the above-mentioned compound is replaced with titanium or hafnium can also be mentioned. In the present embodiment, the racemate of the transition metal compound represented by the general formula (I-4) is usually used as a catalyst component, but R-type or S-type can also be used.

Such a transition metal compound represented by the general formula (I-4) is according to the Journal of Organometallic Chem.288 (1985), pp. 63-67, European Patent Application Publication No. 0,320,762 and Examples. Can be manufactured.

The transition metal compound (A) having a cyclic η-bonded anion ligand has the following general formula (II-1).
) Is a transition metal compound.

In the formula, M is a transition metal of Group 4 of the Long Periodic Table of the Periodic Table of Oxidation +2, +3, +4 having an η5 bond with one or more ligands L, and the transition metal is particularly preferably titanium. .. Further, L is a cyclic η-binding anion ligand, which is independently a cyclopentadienyl group, an indenyl group, a tetrahydroindenyl group, a fluorenyl group, a tetrahydrofluorenyl group, or an octahydrofluorenyl group. , These groups are hydrocarbon groups containing up to 20 non-hydrogen atoms, halogens, halogen-substituted hydrocarbon groups, aminohydrocarbi groups, hydrocarbioloxy groups, dihydrocarbylamino groups, dihydrocarbylphosphino groups, silyl groups. , Aminosilyl group, Hydrocarbyloxysilyl group and Halosilyl group may each have 1 to 8 substituents independently selected, and further, two Ls contain up to 20 non-hydrogen atoms. It may be bonded by a divalent substituent such as diyl, halohydrocarbaziyl, hydrocarbyleneoxy, hydrocarbyleneamino, diradiyl, halosiladiyl, aminosilane.

Each of X independently has a monovalent anionic sigma-bonded ligand having up to 60 non-hydrogen atoms, a divalent anionic sigma-bonded ligand that divalently binds to M, or M and It is a divalent anion σ-bonded ligand that binds to L with a valence of 1 each.

X'is a neutral Lewis base-coordinating compound independently selected from phosphines, ethers, amines, olefins, and / or conjugated diene, each of which has 4 to 40 carbon atoms.

Also, l is an integer of 1 or 2. p is an integer of 0, 1 or 2, and X is a divalent anionic sigma-bonded ligand that binds to a monovalent anionic sigma-bonded ligand or M and L with one valence each. When a child, p is less than l less than the formal oxidation number of M, or when X is a divalent anionic sigma-bonded ligand that divalently binds to M, p is less than the formal oxidation number of M. Less than l + 1. Further, q is 0, 1 or 2. As the transition metal compound, the case of l = 1 in the above formula (1) is preferable.

For example, a suitable example of the transition metal compound is represented by the following formula (II-2).

In the formula, M is titanium, zirconium, or hafnium having a formal oxidation number of +2, +3 or +4, and titanium is particularly preferable.

Further, each of R ³ is independently a hydrogen, a hydrocarbon group, a silyl group, a gelmil group, a cyano group, a halogen, or a composite group thereof, and each can have up to 20 non-hydrogen atoms.

Further, adjacent R ³ each other hydrocarbadiyl, Jirajiiru, or form a divalent derivative may become a cyclic such germadiyl.

Each X "is independently a halogen, a hydrocarbon group, a hydrocarbyloxy group, a hydrocarbylamino group, or a silyl group, each having up to 20 non-hydrogen atoms, and two X's having 5 to 30 carbon atoms. Neutral conjugated diene or divalent derivative may be formed.

Y is −O−, −S−, −NR ^* −, or −PR ^* −, and Z is SiR ^* ₂ , CR ^* ₂ , SiR ^* ₂ SiR ^* ₂ , CR ^* ₂ CR ^* ₂ , CR ^* ₂ ^. = CR ^* , CR ^* ₂ SiR ^* ₂ or GeR ^* ₂ , where R ^* is an independently alkyl or aryl group having 1 to 12 carbon atoms, respectively. Further, n is an integer of 1 to 3.

Further, more preferable examples of the transition metal compound are represented by the following formulas (II-3) and the following formulas (II-4).

In the formula, R ¹⁶ is independently a hydrogen, a hydrocarbon group, a silyl group, a gelmil group, a cyano group, a halogen, or a composite group thereof, and each can have up to 20 non-hydrogen atoms. The transition metal M is titanium, zirconium or hafnium, preferably titanium.

The definitions of Z, Y, X and X'are as described above. p is 0, 1 or 2, and q is 0 or 1. However, when p is 2 and q is 0, the oxidation number of M is +4, and X is halogen, hydrocarbon group, hydrocarbyloxy group, dihydrocarbylamino group, dihydrocarbylphosfide group, hydrocarbylsulfide group, silyl. It is a group or a composite group thereof and has up to 20 non-hydrocarbon atoms.

When p is 1 and q is 0, the oxidation number of M is +3, and X is an allyl group, 2- (N, N-dimethylaminomethyl) phenyl group or 2- (N, N-dimethyl). It is a stabilized anion ligand selected from −aminobenzyl groups, or M has an oxidation number of +4 and X is a derivative of a divalent conjugated diene, or both M and X are metallocyclopentene groups. Is forming.

Further, when p is 0 and q is 1, the oxidation number of M is +2, and X'is a neutral conjugated or unconjugated diene and is optionally substituted with one or more hydrocarbons. Well, the X'can contain up to 40 carbon atoms, forming a π-type complex with M.

Further, in the present invention, the most suitable examples as the transition metal compound are represented by the following formulas (II-5) and the following formulas (II-6).

In the formula, R ¹⁶ is independently hydrogen or an alkyl group having 1 to 6 carbon atoms. Further, M is titanium, Y is −O−, −S−, −NR ^* −, −PR ^* −, and Z ^* is SiR ^* ₂ , CR ^* ₂ , SiR ^* ₂ SiR ^* ₂ , CR ^* ₂ CR ^* ₂ , CR ^* = CR *, CR ^* ₂ SiR ₂ or GeR ^* ₂ , where R ^* is an independent hydrogen or hydrocarbon group, hydrocarbyloxy group, silyl group, alkyl halide. A group, an aryl halide group or a composite group thereof. The R ^* may have up to 20 non-hydrogen atoms, and medium-Z * 2 one R ^* s or Z Medium * optionally R ^* in the Y of R ^* is not a ring May be good.

p is 0, 1 or 2, and q is 0 or 1. However, when p is 2 and q is 0, the oxidation number of M is +4, and X is independently a methyl group or a hydrobenzyl group. Further, when p is 1 and q is 0, the oxidation number of M is +3, and X is a 2- (N, N-dimethyl) -aminobenzyl group, or the oxidation number of M is +4. , And X is 2-butene-1,4-diyl.

When p is 0 and q is 1, the oxidation number of M is +2, and X'is 1,4-diphenyl-1,3-butadiene or 1,3-pentadiene. The diene is an example of an asymmetric diene forming a metal complex, and is actually a mixture of each geometric isomer.

[Organoaluminium oxy compound (B)]
An annular aluminoxane having a structure represented by the general formula {-Al (R ¹⁷ ) -O-} j, and a structure represented by the general formula R ¹⁷ {-Al (R ¹⁷ ) -O-} _k AlR ¹⁷ _2. As a specific example of R ¹⁷ in the linear aluminoxane having, an alkyl group such as a methyl group, an ethyl group, a normal propyl group, an isopropyl group, a normal butyl group, an isobutyl group, a normal pentyl group and a neopentyl group can be exemplified. .. Further, R ¹⁷ may span a plurality of types in the same molecule. j is an integer of 2 or more, and k is an integer of 1 or more. Preferably R is a methyl group or an isobutyl group, j is 2-40 and k is 1-40.

The above aluminoxane is made by various methods. The method is not particularly limited and may be produced according to a known method. For example, it is prepared by contacting water with a solution of trialkylaluminum (for example, trimethylaluminum) in a suitable organic solvent (such as a service hydrocarbon such as benzene or an aliphatic hydrocarbon such as hexane). Further, a method of contacting trialkylaluminum (for example, trimethylaluminum) with a metal salt containing water of crystallization (for example, copper sulfate hydrate) can be exemplified. The aluminoxane thus obtained is usually considered to be a mixture of a cyclic structure and a linear structure.

[Compound (C) having a phenol structure]
A hindered phenolic compound that is generally used as an antioxidant is preferable.

In addition to phenolic ones, for example, there are bisphenol type, monophenol type, amine / ketone type, aromatic secondary amine type, polyphenol type and the like. These antioxidants may be used in combination with the above-mentioned hindered phenolic antioxidants.

As described above, the antioxidant used in the present invention is a hindered phenolic agent, and more specifically, n-octadecyl-3- (3', 5'-di-t-butyl-4'-. Hydroxyphenyl) -propionate, n-octadecyl-3- (3'-methyl-5'-t-butyl-4'-hydroxyphenyl) -propionate, n-tetradecyl-3- (3', 5'-di-t -Butyl-4'-hydroxyphenyl) -propionate, 1,6-hexanediol-bis- [3- (3,5-di-t-butyl-4-hydroxyphenyl) -propionate], 1,4-butanediol -Bis- [3- (3,5-di-t-butyl-4-hydroxyphenyl) -propionate], 2,2'-methylenebis- (4-methyl-t-butylphenol), triethylene glycol-bis- [ 3- (3-t-Butyl-5-methyl-4-hydroxyphenyl) -propionate], tetrakis [methylene-3- (3', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane , 3,9-bis [2- {3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionyloxy} -1,1-dimethylethyl] 2,4,8,10-tetraoxaspiro (5,5) Undecane, N, N'-bis-3- (3', 5'-di-t-butyl-4'-hydroxyphenyl) propionylhexamethylenediamine, N, N'-tetramethylene-bis- 3- (3'-methyl-5'-t-butyl-4'-hydroxyphenol) propionyldiamine, N, N'-bis- [3- (3,5-di-t-butyl-4-hydroxyphenol) Propionyl] hydrazine, N-salicyloyl-N'-salicylidene hydrazine, 3- (N-salicyloyl) amino-1,2,4-triazole, N, N'-bis [2- {3- (3,5-) Di-t-butyl-4-hydroxyphenyl) propionyloxy} ethyl] oxyamide, pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], N, N'- Hexamethylene bis- (3,5-di-t-butyl-4-hydroxy-hydrocinnamide and the like can be mentioned, but not limited to these, preferably triethylene glycol-bis- [3- (3). -T-Butyl-5-methyl-4-hydroxyphenyl) -propionate], tetrakis [methire N-3- (3', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane, 1,6-hexanediol-bis- [3- (3,5-di-t-butyl-) 4-Hydroxyphenyl) -propionate], pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], N, N'-hexamethylenebis- (3,5-) It is di-t-butyl-4-hydroxy-hydrocinnamide. Specific trade names of hindered phenolic compounds include "Adecastab" AO-20, AO-30, AO-40, AO-50, AO-60, AO-70, AO-80, of Asahi Denka Kogyo Co., Ltd. AO-330, "Irganox" manufactured by Chivas Specialty Chemical Co., Ltd. 245,259,565,1010,1035,107,1098,1222,1330, 1245,1520, 3114,5057, Sumitomo Chemical Co., Ltd. "Smilizer" BHT-R, Examples thereof include MDP-S, BBM-S, WX-R, NW, BP-76, BP-101, GA-80, GM, GS, and "Sianox" CY-1790 manufactured by Sianamide.
The aluminoxane (B) may contain unreacted trialkylaluminum in addition to the linear or cyclic organoaluminum polymer. The trialkylaluminum may cause chain transfer of the polyolefin, especially the polymer in the living polymerization, and inhibit the high molecular weight of the living polymer. By blending (C), this polymerization reaction inhibitory component can be detoxified, and the generation of a gel-like substance that does not solidify in a solvent starting from unreacted trialkylaluminum can be suppressed, so that the particle size is large. A spherical polyethylene powder can be obtained with.

As a method for preparing an ethylene polymerization catalyst, first, each of (A), (B), and (C) is dissolved and diluted with an inert hydrocarbon under an inert gas. After that, (B) and (C) are preferably mixed for 5 minutes or more and 2 hours, and then (A) is added to activate the mixture. By mixing (B) and (C) first and then adding (A), the generation of a gel-like substance that does not solidify in a solvent starting from unreacted trialkylaluminum is suppressed and promoted. Therefore, a spherical polyethylene powder having a large particle size can be obtained.

The mixing temperature at the time of mixing each of the above components is usually -30 to 80 ° C., preferably 0 to 50 ° C., and the contact time is 5 minutes to 5 hours, preferably 30 minutes to 2 hours.

The concentration of the activation catalyst obtained by mixing each of the above components is 10 ^-7 to 10 ^-4 mol, preferably 10 ^-6 to 10 ^-5 mol, as the molar concentration of the transition metal atom in the component (A). Prepared.

Specific examples of the inert hydrocarbon solvent used in the preparation of the olefin polymerization catalyst in the present invention are aliphatic hydrocarbons such as pentane, hexane, heptane, octane, decane, dodecane and kerosene; cyclopentane, cyclohexane and methylcyclopentane. Aliphatic hydrocarbons such as; aromatic hydrocarbons such as benzene, toluene and xylene; halogenated hydrocarbons such as ethylene chloride, chlorobenzene and dichloromethane or mixtures of these solvents can also be used. In particular, from the viewpoint of controlling the circularity of the polyethylene powder, the aromatic hydrocarbon of the mixed solvent is preferably 40% by mass or more, more preferably 50% by mass or more, still more preferably 60% by mass or more.

The molar ratio [Al / M] of the aluminum atom in the organoaluminum oxy compound (B) to the transition metal atom (M) in the component (A) is usually 50 or more and 50,000 or less, preferably 100 or more and 10000 or less. It is preferably used in an amount of 200 or more and 1000 or less. The molar ratio [Ph-OH / Al] of Al derived from trialkylaluminum existing as a monomer contained in the component (B) to the phenol group subject to steric shielding of the component (C) is usually 0.3 or more and 0. It is used in an amount of 0.7 or less, preferably 0.4 or more and 0.6 or less.

Conventionally, as a technological development of polyethylene powder suitable for solid phase stretching, the use of homogeneous catalysts has a problem of non-uniform shape of fouling and polymer, and it is difficult to achieve both good physical properties with low entanglement and industrial productivity. It was. On the other hand, the use of a supported heterogeneous catalyst has problems such as high entanglement of the polymer with active site proximity due to support, heterogeneous physical properties and reduced activity due to the heterogeneous catalyst active site structure in the supported state, and the presence of residues in the polymer. Existed. The present invention is generally considered in the addition of BHT for removing the reaction inhibitory component trialkylaluminum contained in the cocatalyst methylarmoxane in order to achieve both polymerization fouling of a homogeneous catalyst and poor shape and low entanglement. The amount of stoichiometric addition to detoxify and remove the trialkylaluminum is at least 2 equivalents, or it is effective to reduce the amount to 0.3 equivalents or more and less than 0.7 equivalents instead of excessive addition. This is a manufacturing method that cannot be easily derived by those skilled in the art.

[Manufacturing method of polyethylene powder]
As a method for producing the polyethylene powder, either a vapor phase polymerization method, a liquid phase polymerization method, or a slurry polymerization method is used. In the slurry polymerization method, as the polymerization solvent, for example, an aromatic solvent such as toluene or xylene, or a hydrocarbon (propane, cyclohexane, isobutane, n-butane, n-pentane, isopentane, neopentane, n-hexane and n-heptane) can be used. Etc.). Mixtures of these solvents can also be used. In particular, from the viewpoint of controlling the particle size distribution and molecular weight in which polyethylene powder having a certain size is present in a certain weight ratio or more, the hydrocarbon content of the mixed solvent is preferably 70 wt% or more, more preferably 80 wt% or more, and further. It is preferably 90 wt% or more. The polymerization temperature is −50 ° C. or higher and 100 ° C. or lower, preferably −20 ° C. or higher and 90 ° C. or lower, and more preferably 0 ° C. or higher and 80 ° C. or lower. The polymerization pressure is not particularly limited, but is, for example, 0.1 MPa or more and 9.8 MPa or less, preferably 0.3 MPa or more and 5.0 MPa or less, and more preferably 0.5 MPa or more and 2.0 MPa or less.

The polymerization reaction in the method for producing polyethylene powder can be carried out by any of batch type, semi-continuous type and continuous type, but it is preferable to carry out polymerization by a continuous type. By continuously supplying ethylene gas, solvent, catalyst, etc. into the polymerization system and continuously discharging it together with the produced ethylene polymer, the polyethylene powder residence time in the polymerizer varies, so that the polyethylene powder is uniformly uniform. A polyethylene powder that is not biased to a narrow particle size distribution can be obtained. Further, the relatively large polyethylene powder of 50 mesh or more of the present embodiment produced in the polymerization is discharged without growing too much. Therefore, the continuous type is preferable. It is also possible to carry out the polymerization in two or more stages having different reaction conditions.
Regarding the polymerization stirring in the polymerizer, the rotation speed of the rotary shaft of the stirring blade which is the stirring power source is preferably 200 to 1200 rpm, more preferably 400 to 1000 rpm, and 600 to 900 rpm from the viewpoint of the size of the obtained polyethylene powder. More preferred.

By adding hydrogen as a chain transfer agent in the polymerization system at an appropriate concentration, it tends to be possible to control the molecular weight in an appropriate range. By adding hydrogen to the polymerization system, in addition to controlling the molecular weight, there is a tendency that chain transfer of the catalyst can be promoted and polymerization growth can be suppressed. This tends to suppress the rapid growth of polymer chains and prevent the formation of distorted particles. When hydrogen is added into the polymerization system, the molar fraction of hydrogen is preferably 0 mol% or more and 30 mol% or less, and more preferably 3.0 mol% or more and 25 mol% or less with respect to the entire system. , 5.0 mol% or more and 20 mol% or less is more preferable.

Further, it is preferable that the catalyst and the co-catalyst are brought into contact with each other in advance. Although it is added into the polymerization system from the catalyst introduction line, it is preferable that the discharge port of the catalyst introduction line exists in a gas phase that does not come into contact with the liquid phase.

When the polymerization or copolymerization of ethylene is carried out using the polymerization catalyst (D) as described above, the polymerization catalyst has a reaction solvent 1 as the amount of the transition metal atom in the transition metal compound (A) contained in the catalyst. It is usually used in an amount such that it is usually 10-9 to 10-3 mol, preferably 10-7 to 10-4 mol, per liter. At this time, if necessary, an organoaluminum oxy compound (B) or a mixture of (B) and (C) can be used as a scavenger that traps the catalyst poison in the reactor before adding the catalyst. In this case, the amount of the organoaluminum oxy compound is 0.1 to 50,000, preferably 0.2 to 3000, more preferably 0.25 to 100 mol, per mol of the transition metal atom in the transition metal compound (A). The amount is desirable. Further, in the case of batch polymerization, the polymerization may be started by raising the monomer to which the polymerization catalyst (D) is added to the above pressure to stabilize it, or the monomer is first raised to a predetermined pressure and then the catalyst. May be added.
Further, the polymerization catalyst (D) activated after mixing (A), (B) and (C) and allowing a predetermined reaction time to elapse is preferably within 1 day until the polymerization is added to the reactor. Within hours is even more preferred, more preferably within 2 hours.

The solvent separation method can be performed by a decantation method, a centrifugation method, a filter filtration method, or the like, but a centrifugation method having good separation efficiency between the polyethylene powder and the solvent is more preferable. The amount of the solvent contained in the polyethylene powder after the solvent separation is not particularly limited, but is 70% by mass or less, more preferably 60% by mass or less, still more preferably 50% by mass or less, based on the weight of the polyethylene powder. By drying and removing the solvent in a state where the solvent contained in the polyethylene is small, the metal, the inorganic component, the low molecular weight component and the like contained in the solvent tend not to remain in the polyethylene powder.
The method for deactivating the catalyst used for the polyethylene powder of the present embodiment is not particularly limited, but it is preferably carried out after separating the polyethylene and the solvent. By introducing a drug for inactivating the catalyst after separation from the solvent, it is possible to reduce the precipitation of low molecular weight components, catalyst components and the like contained in the solvent.
Examples of the agent that inactivates the catalytic system include oxygen, water, alcohols, glycols, phenols, carbon monoxide, carbon dioxide, ethers, carbonyl compounds, and alkins.

The drying temperature after separating the solvent is not particularly limited, but is preferably 60 ° C. or higher and 120 ° C. or lower, more preferably 70 ° C. or higher and 115 ° C. or lower, from the viewpoint of controlling the surface area of the polyethylene powder. Yes, more preferably 80 ° C. or higher and 110 ° C. or lower. When the drying temperature is 60 ° C. or higher, efficient drying tends to be possible. Further, when the drying temperature is 120 ° C. or lower, the polyethylene powder obtained by the polymerization is prevented from being melted and highly entangled due to an excessive heat history. In addition, the polyethylene powder does not become an ambient environment above the melting point, which tends to prevent the particles from partially melting. As a result of the polyethylene powder particles colliding with each other and fusing together, there is a tendency to suppress the formation of macromolecules having a shape far from the perfect circle with a reduced circularity. For the same reason, the residence time in the dryer is not particularly limited, but is preferably 1.5 hours to 5 hours, more preferably 2 hours or more and 3 hours.

[Use]
The polyethylene powder of this embodiment can be used for various purposes. Among them, since it is excellent in solid phase stretchability, it can be used for sheets and fibers obtained by solid phase stretch molding. Therefore, the present invention includes a molded product (preferably solid phase stretched fiber) containing the polyethylene powder of the present embodiment as a component. The molded product (preferably solid phase stretched fiber) of the present invention can be obtained by molding, for example, the polyethylene powder of the present embodiment.

The fibers obtained by the solid-state stretching process according to the present invention can be used for various sports clothing, high-performance textiles such as bulletproof / protective clothing / protective gloves and various safety products, tag ropes / mooring ropes, yacht ropes, construction ropes, etc. Various rope products, various braided products such as fishing threads and blind cables, net products such as fishing nets and ball-proof nets, reinforcing materials such as chemical filters and battery separators or various non-woven fabrics, curtain materials such as tents, helmets and ski boards. It can be widely applied in industry, such as for sports such as, speaker cones, prepregs, and reinforcing fibers for composites such as concrete reinforcement.

The present embodiment will be described in more detail with reference to the following specific examples and comparative examples, but the present embodiment is not limited to the following examples and comparative examples as long as the gist of the present embodiment is not exceeded. Various physical properties and evaluations in Examples and Comparative Examples described later were measured and evaluated by the methods shown below.

(Physical characteristics 1) Particle size distribution The proportion (mass ratio) of particles having a particle size of 425 μm or more in polyethylene powder is 10 types of sieves specified in JIS Z8801 (opening: 710 μm, 500 μm, 425 μm, 355 μm, 300 μm, Prepare an integration curve obtained by integrating the mass of polyethylene powder remaining on various sieves from the side with a small opening, which is obtained when 100 g of polyethylene powder is classified using (212 μm, 150 μm, 106 μm, 75 μm, 53 μm). did. The ratio (weight ratio) of the weight of the particles having a size of 425 μm or more to the total weight was calculated.

(Physical characteristics 2) Particle hardness In polyethylene powder, particles having a particle size of 300 μm or more were separated from particles having a mesh size of 300 μm or more and 1180 μm or less using a sieve having an opening of 1180 μm. The load of the separated polyethylene powder in a displacement state of 40% particle size was measured by a crush strength test as an index of particle hardness. First, the polyethylene powder remaining on the sieve having a particle size distribution of (physical characteristics 1) of 300 μm or more was recovered. Next, using "BHT-500" manufactured by Seishin Enterprise Co., Ltd., under the conditions of room temperature of 20 ° C. and humidity of 31%, the load cell is 1000 gf and the crushing speed is 0.20 mm / sec for each particle. Crush strength test was carried out. From the obtained measurement data, the load was extracted when the particle size at the start of the measurement was 100% and the particle size displacement was 40% (40% particle size displacement state). For one sample, 100 particles were measured and the average value was calculated.

(Physical characteristics 3) Viscosity average molecular weight (Mv)
Using polyethylene powder as a sample, the viscosity average molecular weight (Mv) of polyethylene powder was determined according to ISO1628-3 (2010) by the method shown below. First, 20 mg of polyethylene powder is weighed in the melting tube, the melting tube is replaced with nitrogen, and then 20 mL of decahydronaphthalene (2,6-di-t-butyl-4-methylphenol added 1 g / L) is added. , 150 ° C. for 2 hours to dissolve the polyethylene powder. In a constant temperature bath of the solution 135 ° C., Cannon - Fenske viscometer (Shibatakagakukikaikogyo Co. Ltd. Product No. -100) was used to measure drop time between the marked lines (t _s). Similarly, the polyethylene powder quantity 10 mg, 5 mg, for even samples was changed to 2 mg, it was measured in the same manner as described above fall time between the marked lines (t _s). In addition, the fall time (t _b ) of only decahydronaphthalene without polyethylene powder as a blank was measured. The reduced viscosity (η _sp / C) of polyethylene powder obtained according to the following formula is plotted and a linear formula of the concentration (C) (unit: g / dL) and the reduced viscosity of polyethylene powder (η _sp / C). Was derived, and the ultimate viscosity ([η]) extrapolated to a concentration of 0 was determined.
_{η sp / C = (t s} / t b -1) /0.1 :( Unit: dL / g)
Next, the viscosity average molecular weight (Mv) was calculated using the value of the ultimate viscosity [η] in the following formula.
Mv = (5.34 × 10 ⁴ ) × [η] ^1.49

(Physical characteristics 4) Melting heat absorption by differential scanning calorimetry (DSC) ΔH
Measurements were made using a "Perkin Elmer Pyris1 DSC" as a differential scanning calorimetry (DSC). In a reduced pressure environment of 0.1 to 0.5 kPa, polyethylene powder given a heat history of 110 ° C. for 6 hours was used as a measurement sample, and 8.3 to 8.5 mg was weighed with an electronic balance and placed in an aluminum sample pan. I put it in. An aluminum cover was attached to this pan and installed in the differential scanning calorimeter. The sample and reference sample were held at 50 ° C. for 1 minute while purging nitrogen at a flow rate of 20 mL / min, then heated from 50 ° C. to 180 ° C. at a heating rate of 10 ° C./min, held at 180 ° C. for 5 minutes, and then cooled. It was cooled to 50 ° C. at 10 ° C./min. The baseline of the temperature rising DSC curve obtained at that time was corrected, the peak area was calculated with the analysis software "Pyris software (version7)", and the peak area was divided by the sample mass to measure the melt heat absorption amount ΔH and the peak top as the melting point. ..

(Physical properties 5) Circularity (Physical characteristics 2) Polyethylene powder separated by particle hardness was observed in the analysis mode of "Desktop Electron Microscope TM3030" manufactured by Hitachi High-Technology Co., Ltd., acceleration voltage 15 kV, magnification 600 times, and as an image. saved. Next, the image was analyzed with the image analysis software "A image-kun (manufactured by Asahi Kasei Engineering)". The powder site was extracted by binarization to obtain a two-dimensional projection drawing of the particles, and then the circularity ratio of the particle analysis program was selected for this extracted image and executed to obtain the circularity ratio. The average value obtained by analyzing 50 particles with respect to one sample was defined as the circularity.
The circularity is defined as the ratio of the object to the inside of the circle whose center is the center of gravity and whose diameter is the diameter of the circle whose area is equal to the area of the object. For example, in the case of the particle size shown in FIG. 1, the circularity is measured by the formula A.

Circularity (%)
= Area of S2 / (area of S2 + area of S4 + area of S5) × 100

(Physical characteristics 6) Measurement of total content of Si, Mg, Ti, Zr, and Hf (total content of specific inorganic elements) Approximately 0.2 g of polyethylene powder is weighed in a Teflon (registered trademark) decomposition container and high. Purity nitric acid is added, and after pressure decomposition with Milestone General's "Microwave decomposition device ETHOS-TC", the total volume is 50 mL with pure water purified with "Ultrapure water production device" manufactured by Nippon Millipore. Used as a test solution. For the above test solution, quantification of Si, Mg, Ti, Zr, and Hf by the internal standard method using "inductively coupled plasma mass spectrometer (ICP-MS) X series 2" manufactured by Thermo Fisher Scientific Co., Ltd. The total content of Si, Mg, Ti, Zr, and Hf in the polyethylene powder was measured.

(Evaluation 1) Particle adhesion in a high-temperature dry state (evaluation of fluidity)
With respect to the obtained polyethylene powder, 50 g of polyethylene powder was dropped using a funnel for drop time measurement (fluidity evaluation) conforming to JIS Z2502 in an environment of 70 ° C. and 30% relative humidity in a constant temperature and humidity chamber. It was. The dropped polyethylene powder was collected and dropped again from the upper part, which was repeated 10 times in total, and finally the weight of the polyethylene powder adhering to the inner slope (weight of adhering particles) was measured. The measured value was used as an index for liquidity evaluation and evaluated according to the following evaluation criteria.

(Evaluation criteria)
⊚: The weight of adhered particles is less than 8.0 mg.
◯: The weight of adhered particles is 8.0 mg or more and less than 20.0 mg.
X: The weight of adhered particles is 20 mg or more.

(Evaluation 2) Degree of pressure bonding between particles by short-time compaction (evaluation of moldability)
3 grams of polyethylene powder was pressed by a press molding machine at a maximum temperature of 126 ° C. and an average pressure of 11 MPa for 10 minutes (cooling was carried out at 25 ° C. for 10 minutes while maintaining 11 MPa). The obtained press sheet was preheated at 140 ° C. for 1 minute and rolled at 130 ° C. with a roll rolling mill having a roll feeding speed of 1 m / min so as to have a draw ratio of 6 times. The sheet obtained by the rolling process is cut out, set in a tensile tester (Instron Corporation, INSTRON5564) so that the chuck distance is 15 mm, and 100 from the press sheet in the same direction as roll rolling at 130 ° C. and 120 mm / min. It was stretched to double. The stretching test was performed 20 times, the presence or absence of breakage during stretching was counted, and the breaking rate was measured. The measured value was used as an index of sheet strength unevenness and evaluated according to the following evaluation criteria. A rating of ⊚ or 〇 means that the polyethylene powder has excellent molding processability.

(Evaluation criteria)
⊚: The breaking rate exceeded 0% and was 5% or less. ◯: The breaking rate exceeded 5% and was 10% or less.
X: The breaking rate exceeded 10%.

(Evaluation 3) Uniform thickness of stretched sheet after short-time compaction (appearance evaluation)
3 grams of polyethylene powder was pressed by a press molding machine at a maximum temperature of 126 ° C. and an average pressure of 11 MPa for 3 minutes (cooling was carried out at 25 ° C. for 10 minutes while maintaining 11 MPa). The obtained press sheet was preheated at 140 ° C. for 1 minute and rolled at 130 ° C. with a roll rolling mill having a roll feeding speed of 1 m / min so as to have a draw ratio of 6 times. The sheet obtained by the rolling process is cut out, set in a tensile tester (Instron Corporation, INSTRON5564) so that the chuck distance is 15 mm, and 100 from the press sheet in the same direction as roll rolling at 130 ° C. and 60 mm / min. It was stretched to double. The obtained sheet was cut into a width of 5 mm and a length of 100 mm, and the thickness was measured at intervals of 15 mm in the stretching flow direction. The difference between the maximum and minimum thickness values was calculated. The calculated value was used as an index of sheet thickness uniformity and evaluated according to the following evaluation criteria. If the evaluation is ⊚ or 〇, it means that the appearance when molding the polyethylene powder is excellent.

(Evaluation criteria)
⊚: The difference in thickness was 0.03 mm or less.
◯: The difference in thickness exceeded 0.03 mm and was 0.05 mm or less.
X: The difference in thickness exceeded 0.05 mm.

(Evaluation 4) White streak evaluation of sheet (appearance evaluation)
3 grams of polyethylene powder was pressed by a press molding machine at a maximum temperature of 126 ° C. and an average pressure of 11 MPa for 3 minutes (cooling was carried out at 25 ° C. for 10 minutes while maintaining 11 MPa). The obtained press sheet was preheated at 140 ° C. for 1 minute and rolled at 130 ° C. with a roll rolling mill having a roll feeding speed of 1 m / min so as to have a draw ratio of 6 times. The presence or absence of white streaks (opaque) in the sheet area inside 7 mm from the outer edge of the rolled sheet was visually evaluated according to the following evaluation criteria. If the evaluation is ⊚ or 〇, it means that the appearance when molding the polyethylene powder is excellent.

(Evaluation criteria)
⊚: White streaks could not be visually confirmed.
◯: There were white streaks with a width of less than 0.5 mm in the direction perpendicular to the stretching flow direction.
Δ: There were white streaks having a width of 0.5 mm or more and 1.5 mm or less in the direction perpendicular to the stretching flow direction.
X: There were white streaks with a width of more than 1.5 mm in the direction perpendicular to the stretching flow direction.

[Example 1]
2,6-di-tert-butyl-p-cresol in "MMAO-3A / toluene (modified methylarmoxane, 5.7 wt% toluene solution containing Al)" manufactured by Toso Finechem Co., Ltd. at 20 ° C. in a nitrogen atmosphere. A toluene solution (BHT) was added, and a modified MMAO solution [A-1] was prepared so that the molar ratio of BHT to Al of AlMe ₃ and Ali-Bu ₃ contained in MMAO-3A was 0.5. After stirring for 5 minutes, a toluene solution of [(N-t-butylamide) (tetramethyl-η5-cyclopentadienyl) dimethylsilane] titanium-dichloride (CGC dichloride complex) was added to the Al amount of MMAO with respect to CGC. Add the dichloride complex so that the molar ratio of Ti is 0.005, and further, so that the solvent ratio of toluene and n-hexane is 60:40, n-hexane manufactured by Maruzen Petrochemical (after simple distillation, molecular sieve). After adding (degassed for 20 minutes), the mixture was stirred for 30 minutes to prepare an activation solvent [A-2]. 800 mL of hexane was added to a 1.5 L autoclave fully substituted with nitrogen, and then the inside of the system was pressurized to 8.9 kg / cm ₂ of ethylene to keep the autoclave temperature at 45 ° C. while continuously supplying ethylene. 1.0 mL of the above [A-1] was added as a scavenger, and the mixture was stirred for 5 minutes. Then, the activation catalyst [A-2] was introduced into the autoclave 30 minutes after the reaction was completed by a pump in an amount such that the titanium concentration in the activation catalyst [A-2] was 7.5 × 10 ^-6 mol / L. did. The position of the feed discharge port at the time of introduction was set to 800 mL of hexane at the liquid level and at the gas phase site outside the liquid. At this time, the solvent composition during the polymerization was 99.5 / 0.5 with n-hexane / toluene. The mixture was stirred at a rotation speed of 600 rpm for 2 hours while maintaining the autoclave temperature at 45 ° C. After completion of the polymerization reaction, the unreacted gas is purged, the contents of the autoclave are put into 1000 ml of acidic methanol containing 5% by mass of hydrochloric acid, the precipitated polymer is filtered off, and the liquid content becomes 44% by mass in a stretching separator. The mixture was pre-dried until then dried under nitrogen at 70 ° C. for 2 hours to obtain 132 g of polyethylene powder PE. With respect to the polyethylene powder PE1 obtained in Example 1, the measurements and evaluations of (Physical Properties 1) to (Physical Properties 6) and (Evaluation 1) to (Evaluation 4) were carried out according to the above-mentioned method. The results are shown in Table 1.

[Example 2]
Polyethylene powder PE2 was obtained by the same operation as in Example 1 except that the metal complex CGC dichloride was used as the catalyst in place of bispentadienyl titanium dichloride. Table 1 shows the physical characteristics of the polyethylene powder PE2 and the results of each evaluation.

[Example 3]
Modified alumoxane MMAO-3A was used in "TMAO-200" manufactured by Toso Finechem Co., Ltd., the toluene / n-hexane composition ratio at the time of preparing the activation catalyst was 45/55, and the polymerization solvent n-hexane / toluene composition ratio was 70/30. Polyethylene powder PE3 was obtained by the same operation as in Example 1 except that the stirring rotation speed was changed to 1100 rpm. Table 1 shows the physical characteristics of the polyethylene powder PE3 and the results of each evaluation.

[Example 4]
Same as Example 1 except that the molar ratio of BHT to Al of AlMe ₃ and Ali-Bu ₃ contained in MAO was changed to 1, and the toluene / n-hexane composition ratio at the time of preparing the activation catalyst was changed to 30/70. Polyethylene powder PE4 was obtained by the above operation. Table 1 shows the physical characteristics of the polyethylene powder PE4 and the results of each evaluation.

[Example 5]
Preliminary drying by centrifuging the modified Armoxane MMAO-3A on TMAO-200 manufactured by Toso Finechem Co., Ltd., keeping the toluene / n-hexane composition ratio at 10/90 when preparing the activation catalyst, keeping the polymerization temperature at 60 ° C. Polyethylene powder PE5 was obtained by the same operation as in Example 1 except that the liquid content was changed to 80% by mass. Table 1 shows the physical characteristics of the polyethylene powder PE5 and the results of each evaluation.

[Comparative Example 1]
The polyethylene powder PE6 of Comparative Example 1 was obtained by the same operation as in Example 1 except that BHT was not added at the time of preparing the activation catalyst. Table 1 shows the physical characteristics of the polyethylene powder PE6 and the results of each evaluation.

[Comparative Example 2]
After adding the catalyst to MMAO during the preparation of the activation catalyst, the order of addition of BHT was changed, and the polymerization feed was carried out 5 hours after the activation reaction, and the position of the catalyst feed discharge port was set in the liquid phase. The polyethylene powder PE7 of Comparative Example 2 was obtained by the same operation as in Example 1 except for the above. Table 1 shows the physical characteristics of the polyethylene powder PE7 and the results of each evaluation.

[Comparative Example 3]
A modified MMAO solution [A-1] was prepared so that the molar ratio of BHT to Al of AlMe ₃ and Ali-Bu ₃ contained in MAO was 2, and the molar ratio of Ti of CGC to the amount of Al in MMAO was prepared. Prepared to a ratio of 8.3 × 10-4, and before performing catalytic feeding to the polymerization reactor, Aldrich 1,3,5,7,9,11-octaisobutyltetracyclo [7.3.3.15 , 11] Octasiloxane-endo-3,7-diol 97% (POSS diol) was added in an amount of 2.0 × 10-5 mol, and the polymerization stirring speed was changed to 1500 rpm by the same operation as in Example 1. , Polyethylene powder PE8 was obtained. Table 1 shows the physical characteristics of the polyethylene powder PE8 and the results of each evaluation.

[Comparative Example 4]
By the same operation as in Example 1 except that the toluene / n-hexane composition ratio at the time of preparing the activation catalyst was set to 30/70, the position of the catalyst feed discharge port was kept in the liquid phase, and the polymerization temperature was kept at 60 ° C. Polyethylene powder PE9 was obtained. Table 1 shows the physical characteristics of the polyethylene powder PE9 and the results of each evaluation.

[Comparative Example 5]
Polyethylene powder PE10 was obtained by the same operation as in Example 1 except that the polymerization temperature was maintained at 70 ° C. and 3 mol% of hydrogen was added to the polymerization reactor for polymerization. Table 1 shows the physical characteristics of the polyethylene powder PE10 and the results of each evaluation.

[Comparative Example 6]
After adding the catalyst to MMAO at the time of preparing the activation catalyst, the order of addition of BHT was changed so that the molar ratio of BHT to Al of AlMe ₃ and Ali-Bu ₃ contained in MAO was 4. A solution is prepared, and a polymerization feed is carried out 5 hours after the activation reaction. The position of the catalyst feed discharge port is kept in the liquid phase, the polymerization temperature is kept at 60 ° C. Polyethylene powder PE11 was obtained by the same operation as in Example 1 except that the liquid content of the pre-drying was changed to 80 wt%. Table 1 shows each physical property and each evaluation of polyethylene powder PE11.

From the above results, in the polyethylene powder of the present embodiment, the polyethylene powder having a relatively large particle size is present at a certain level or more, and the powder has a certain hardness, so that the particles can be efficiently separated from each other in the solid phase stretching process. It can be seen that the effect of crimping is recognized. The reason for this is not clear, but it is presumed that the filling of the particles is improved and the load on all the particles at the time of compaction is uniformly propagated. The present invention is not limited by this guess. Conventionally, in order to increase the contact surface of polyethylene powder in order to improve the molding processability of the solid phase stretching process, it is common knowledge of those skilled in the art to reduce the particle size and make the particle size of the polymer particles uniform. However, there is no one that pays attention to the existence of large particle size particles and their hardness.

Since the ethylene polymer particles of the present invention have a high molecular weight and crystallinity and have a specific surface shape, a molded product having particularly high strength can be obtained by solid-phase stretching molding, and solid-phase stretching molding can be obtained. The polyethylene powder ethylene of the present invention, which can be suitably used for various purposes, can suppress fouling to a polymerization reactor, a stirring blade, etc. to a minimum, so that plant shutdown does not occur in industrial production. It is also advantageous in terms of cost. In addition, when the obtained polyethylene powder is stretch-molded, the interface between the particles disappears and a uniform sheet can be achieved with high efficiency, so that the productivity of battery separators, gel-spun fibers, sheets, etc. can be further improved. You can expect it. In particular, since the stretched molded product molded by the solid phase stretch molding method has high strength, it can be suitably used for solid phase stretch molding.

Claims (5)

A polyethylene powder having the following characteristics (1) to (4).
(1) The viscosity average molecular weight is 1 million or more and 15 million or less. (2) In the polyethylene powder after giving a heat history at 110 ° C. for 6 hours under a reduced pressure environment of 0.1 to 0.5 kPa. The melting heat absorption amount ΔH measured by the differential scanning calorific value analysis is 230 J / g or more and 293 J / g or less. (3) The proportion of particles having a particle diameter of 425 μm or more in the polyethylene powder is 10% by mass or more and 80. Mass% or less (4) In the crushing strength test of particles having a particle size of 300 μm or more and 1180 μm or less in the polyethylene powder, when the particle size of the particles is displaced to 40% of the particle size at the start of measurement. Load Load is 2.0N or more and 9.0N or less The polyethylene powder according to claim 1, which further has the following property (5).
(5) In the polyethylene powder, the circularity obtained by image analysis of particles having a particle diameter of 300 μm or more and 1180 μm or less is 95% or more. The polyethylene powder according to claim 1 or 2, which further has the following property (6).
(6) The total content of Si, Mg, Ti, Zr, and Hf in the polyethylene powder by inductively coupled plasma mass spectrometry (ICP / MS) is 20 mass ppm or less. A molded product containing the polyethylene powder according to any one of claims 1 to 3 as a component. The molded product according to claim 4, which is a solid phase stretched fiber.