JP2007268777A - Manufacturing method of molded object by injection molding - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an injection molding method of polyethylene capable of preventing the scorching of a resin and capable of shortening the cooling time after injection. <P>SOLUTION: The injection molding method of polyethylene is characterized by injection-molding a mixture containing polyethylene with a density of 900-below 940(kg/m<SP>3</SP>) and an MI of 0.01-100 g/10 min and polyethylene wax of which the density is 890-980(kg/m<SP>3</SP>) and a number average molecular weight (Mn) in terms of polyethylene measured by gel permeation chromatography (GPC) is 500-4,000 and which satisfies the relation of formula (I): B≤0.0075×K [wherein B is the content ratio (wt.%) of the component, of which the molecular weight measured by GPC in terms of polyethylene is 20,000 or above in polyethylene wax and K is the melt viscosity (mPa s) of polyethylene wax at 140°C]. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for producing a molded body by injection molding, and more particularly, to a method for producing a molded body by injection molding using polyethylene in a specific density range and a specific polyethylene wax as raw materials.

  Thermoplastic resins such as polyethylene are plastics that are plasticized by heating and have fluidity, and various molded products are produced by various molding methods. At this time, when injection molding a thermoplastic resin, it is necessary to impart sufficient fluidity to the thermoplastic resin in order to prevent short shots. As a method of imparting sufficient fluidity to a thermoplastic resin, a method of injection molding by adding a plasticizer or a lubricant to the thermoplastic resin is known. For example, a method of molding by applying a molding aid such as oil or polyethylene wax to a thermoplastic resin to be molded has been studied (for example, Patent Documents 1 and 2). However, even if a thermoplastic resin such as polyethylene is injection molded using conventional molding aids, the molding properties themselves tend to improve, but the physical properties of the resulting molded product, such as mechanical strength and heat resistance, are reduced. There was a problem of doing.

On the other hand, as a method without adding a plasticizer or a lubricant, a method is known in which the molding temperature is raised to sufficiently plasticize the thermoplastic resin and injection molding is performed in this state. However, this method has problems such as burning of the resin and deterioration due to heating in order to increase the molding temperature. Further, in the case of continuous injection molding, it is necessary to cool the mold. However, if the molding temperature is raised, there is a problem that it takes time for cooling and productivity is lowered. For this reason, conventionally, in order to shorten the cooling time, a method such as increasing the capacity of the cooling device has been adopted, but a new capital investment is required, which is not economically preferable.
Japanese Patent Publication No. 5-80492 Special table 2003-528948 gazette

  The present invention is intended to solve the problems associated with the prior art as described above, and can prevent burning of the resin and shorten the cooling time after injection in polyethylene injection molding. It aims at providing the injection molding method of polyethylene.

  As a result of diligent research to solve the above problems, the present inventor can perform injection molding at a molding temperature lower than that of a conventional material when injection molding is performed using polyethylene of a specific density range and a specific polyethylene wax as raw materials, and a lubricant or the like. The present inventors have found that a molded product having physical properties equivalent to that of a molded product not using the plasticizer is obtained, and the present invention has been completed.

That is, in the injection molding method according to the present invention, the density measured according to the density gradient tube method of JIS K7112 is in the range of 900 (kg / m ³ ) or more and less than 940 (kg / m ³ ).
According to K7210, polyethylene having an MI measured in the range of 0.01 to 100 g / 10 min at 190 ° C. under a test load of 21.18 N, and a density measured according to the density gradient tube method of JIS K7112 is 890 to 980 (kg / m ³ ), the number average molecular weight (Mn) in terms of polyethylene measured by gel permeation chromatography (GPC) is in the range of 500 to 4,000, and is represented by the following formula (I) It is characterized by injection-molding a mixture containing polyethylene wax satisfying the above.
B ≦ 0.0075 × K (I)
(In the above formula (I), B is a content ratio (% by weight) of a component having a polyethylene conversion molecular weight of 20,000 or more in the polyethylene wax when measured by gel permeation chromatography, and K Is the melt viscosity (mPa · s) of the polyethylene wax at 140 ° C.)
The polyethylene wax preferably further satisfies the relationship represented by the following formula (II).
A ≦ 230 × K ^(-0.537) (II)
(In the above formula (II), A is a content ratio (% by weight) of a component in which the molecular weight in terms of polyethylene in the polyethylene wax is 1,000 or less when measured by gel permeation chromatography, and K Is the melt viscosity (mPa · s) of the polyethylene wax at 140 ° C.)

  According to the present invention, by adding polyethylene wax, the fluidity of polyethylene can be ensured even at low temperatures. As a result, it is possible to perform injection molding at a low temperature and prevent scorching of the resin during injection molding. Furthermore, since it has sufficient fluidity even at a molding temperature lower than that in the case of not containing polyethylene wax, the resin can be sufficiently filled to the details of the mold, and short shots can be prevented. In addition, the obtained molded product does not show deterioration in characteristics. Furthermore, since the molding temperature is low, the mold cooling time can be shortened, the molding cycle can be increased, and productivity in existing facilities can be improved.

Hereinafter, the present invention will be described in detail.
First, raw materials used in the injection molding of the present invention will be described.
〔polyethylene〕
In the present invention, polyethylene means a homopolymer of ethylene or ethylene and a small amount of α-, having an MI measured in the range of 0.01 to 100 g / 10 min at 190 ° C. and a test load of 21.18 N according to JIS K7210. A copolymer with olefin or a blend thereof.

The polyethylene used in the present invention has a density of 900 (kg / m ³ ) or more and 940 (kg
/ M ³ ) as long as it is less than the range. Specific examples include low density polyethylene, medium density polyethylene, linear linear low density polyethylene, ultra-low density polyethylene, or blends thereof.

In the present invention, the measurement conditions for the MI and density of polyethylene are as follows.
(MI)
The measurement was performed in accordance with JIS K7210 at 190 ° C. and a test load of 21.18 N.

(density)
It was measured according to the density gradient tube method of JIS K7112.
As described above, the polyethylene has a density of 900 (kg / m ³ ) or more and 940 (kg
/ M ³⁾ is in the range of less than, but preferably in the range of 900~930 (kg / m ^3).

When the density of polyethylene is in the above range, the resulting molded article is excellent in texture, rigidity, impact resistance, and chemical resistance.
Moreover, as MI of the said polyethylene, the range of 0.1-30.0 g / 10min is preferable, and the range of 0.5-15.0 g / 10min is more preferable. When the MI of polyethylene is in the above range, it is possible to obtain a molded article having an excellent balance of molding processability and mechanical strength, and excellent texture, rigidity, impact resistance and chemical resistance.

The shape of the polyethylene is not particularly limited, but is usually pellet-shaped or tablet-shaped particles.
[Polyethylene wax]
In the present invention, the polyethylene wax means a homopolymer of ethylene or ethylene and a small amount of α- in which the number average molecular weight (Mn) in terms of polyethylene measured by gel permeation chromatography (GPC) is in the range of 500 to 4,000. A copolymer with olefin or a blend thereof. The polyethylene-converted number average molecular weight (Mn) of the polyethylene wax is determined from gel permeation chromatography (GPC) measurement under the following conditions.

(Number average molecular weight (Mn))
The number average molecular weight was determined from GPC measurement. The measurement was performed under the following conditions. The number average molecular weight was determined based on the following conversion method by creating a calibration curve using commercially available monodisperse standard polystyrene.
Apparatus: Gel permeation chromatograph Alliance GPC2000 (manufactured by Waters)
Solvent: o-dichlorobenzene column: TSKgel column (manufactured by Tosoh Corporation) x 4
Flow rate: 1.0 ml / min Sample: 0.15 mg / mL o-dichlorobenzene solution temperature: 140 ° C.
Molecular weight conversion: PE conversion / General calibration method

In addition, the coefficient of the Mark-Houwink viscosity formula shown below was used for calculation of general-purpose calibration.
Coefficient of polystyrene (PS): KPS = 1.38 × 10 ⁻⁴ , aPS = 0.70
Coefficient of polyethylene (PE): KPE = 0.06 × 10 ⁻⁴ , aPE = 0.70
The polyethylene wax used in the present invention has a density in the range of 890 to 980 (kg / m ³ ). The density of the polyethylene wax is a value measured by the density gradient tube method of JISK7112.

The polyethylene wax of the present invention is characterized in that there is a specific relationship represented by the following formula (I) between its molecular weight and melt viscosity.
B ≦ 0.0075 × K (I)
Here, in the above formula (I), B is a content ratio (weight%) of a component having a polyethylene conversion molecular weight of 20,000 or more in the polyethylene wax when measured by gel permeation chromatography. ). K is the melt viscosity (mPa · s) at 140 ° C. of the polyethylene wax measured with a Brookfield (B type) viscometer.

The polyethylene wax that satisfies the above formula (I) exhibits good dispersibility with respect to polyethylene. When such a polyethylene wax is used, the fluidity is improved as compared with the case where no polyethylene wax is added, and an injection-molded body having the same mechanical properties can be obtained even by injection molding at a low molding temperature. A decrease in mechanical properties due to the addition of wax can be suppressed. In addition, this injection-molded body is excellent in mold releasability and can prevent mold contamination. Further, since injection molding at a low molding temperature is possible, the cooling time is shortened and the molding cycle is improved. Furthermore, by lowering the molding temperature, it is possible not only to suppress the thermal deterioration of the resin and the resin strength, but also to suppress the scorching and black spots of the resin.

  Conventionally, when polyethylene wax having a low melt viscosity is mixed with polyethylene and injection molding is performed, the viscosity of the entire mixture is lowered, so that the fluidity tends to be improved as compared with the case where polyethylene wax is not added. The mold releasability of the obtained molded product tends to decrease, and the mechanical properties are not always sufficient.

  As a result of investigation by the present inventors, in the mechanical properties of the molded product obtained by injection molding, the proportion of the component having a molecular weight of 20,000 or more in the polyethylene wax used is extremely important in relation to the melt viscosity. I understood that. Although the detailed mechanism is not clear, when the polyethylene wax and polyethylene are melt-kneaded in the molded body, among the whole polyethylene wax, the component having a molecular weight of 20,000 or more has a melting behavior even in the whole wax. From the viewpoint of the specific melt viscosity of the entire polyethylene wax, the polyethylene wax cannot be dispersed well in the polyethylene unless the molecular weight is 20,000 or more. It is presumed to affect the mechanical properties and mold releasability of the molded body.

  A polyethylene wax having a B value in the above range can be prepared using a metallocene catalyst. Among the metallocene catalysts, metallocene catalysts whose ligands are non-crosslinked are preferable. As such a metallocene catalyst, a metallocene compound represented by the general formula (1) described later can be exemplified.

  Further, the B value can be controlled by the polymerization temperature. For example, when a polyethylene wax is produced by a metallocene catalyst described later, the polymerization temperature is usually in the range of 100 to 200 ° C., but from the viewpoint of producing the polyethylene wax having the B value described above, the polymerization temperature is preferably Is in the range of 100 to 180 ° C, more preferably in the range of 100 to 170 ° C.

The polyethylene wax of the present invention preferably further has a specific relationship represented by the following formula (II) between its molecular weight and melt viscosity.
A ≦ 230 × K ^(-0.537) (II)
Here, in the above formula (II), A is the content ratio (weight%) of the component whose molecular weight in terms of polyethylene in the polyethylene wax is 1,000 or less when measured by gel permeation chromatography. ). K is the melt viscosity (mPa · s) of the polyethylene wax at 140 ° C.

  Molded articles using polyethylene wax that satisfies the above formula (II) tend to have the same mechanical properties as when polyethylene wax is not added, and the bleed-out from the molded article surface tends to decrease. is there. In addition, this injection-molded body is excellent in mold releasability and can prevent mold contamination. Further, since injection molding at a low molding temperature is possible, the cooling time is shortened and the molding cycle is improved. Furthermore, by lowering the molding temperature, it is possible not only to suppress the thermal deterioration of the resin and the resin strength, but also to suppress the scorching and black spots of the resin.

  As described above, conventionally, when polyethylene wax having a low melt viscosity is applied to polyethylene and injection molding is performed, the viscosity of the entire mixture is lowered, so that fluidity is improved as compared with the case where polyethylene wax is not added. Although there is a tendency, the mold releasability of the resulting molded product tends to decrease, the mechanical properties may be impaired, and bleeding out from the surface of the molded product may also be a problem. .

As a result of the study by the present inventors, the ratio of the component having a molecular weight of 1,000 or less in the polyethylene wax used is extremely important for the mechanical properties of the molded product obtained by injection molding in relation to the melt viscosity. It turns out that. Although the detailed mechanism is not clear, when polyethylene wax and polyethylene are melt-kneaded in a molded product, components having a molecular weight of 1,000 or less are easily melted in the whole polyethylene wax, and the melting behavior thereof is wax. From the viewpoint of the melt viscosity of polyethylene wax as a whole, if it is not less than a certain proportion of components with a molecular weight of 1,000 or less, it will ooze out to the surface, possibly causing deterioration, etc. It is presumed to affect the mechanical properties and bleed out of the body.

  A polyethylene wax having an A value in the above range can be prepared using a metallocene catalyst. Among the metallocene catalysts, metallocene catalysts whose ligands are non-crosslinked are preferable. As such a metallocene catalyst, a metallocene compound represented by the general formula (1) described later can be exemplified.

  Furthermore, the A value can be controlled by the polymerization temperature. For example, when a polyethylene wax is produced with a metallocene catalyst described later, the polymerization temperature is usually in the range of 100 to 200 ° C., but from the viewpoint of producing the polyethylene wax having the A value described above, the polymerization temperature is preferably Is in the range of 100 to 180 ° C, more preferably in the range of 100 to 170 ° C.

The polyethylene wax has a number average molecular weight (Mn) in the range of 500 to 4,000, preferably in the range of 1,000 to 3,800, and particularly preferably in the range of 2,000 to 3,500. When the number average molecular weight (Mn) of the polyethylene wax is in the above range, the dispersion of the polyethylene wax in the polyethylene tends to be better.

  Mn of the polyethylene wax can be controlled by the polymerization temperature or the like. For example, when a polyethylene wax is produced with a metallocene catalyst described later, the polymerization temperature is usually in the range of 100 to 200 ° C., but from the viewpoint of producing a polyethylene wax having the above-mentioned preferred range of Mn, the polymerization temperature is , Preferably, it is the range of 100-180 degreeC, More preferably, it is the range of 100-170 degreeC.

The density of the polyethylene wax ^{(D (kg / m 3)} ) is in the range of 890~980 (kg / m ^3), preferably in the range of ^{895~960 (kg / m 3),} 900~940 (k
The range of g / m ³ ) is more preferred. When the density (D) of the polyethylene wax is within the above range, the dispersion of the polyethylene wax in the polyethylene tends to be better.

  The density of the polyethylene wax depends on the number average molecular weight (Mn) of the polyethylene wax when the polyethylene wax is a homopolymer of ethylene. For example, if the molecular weight of polyethylene wax is lowered, the density of the resulting polymer can be controlled low. When the polyethylene wax is a copolymer of ethylene and α-olefin, the density of the polyethylene wax depends on the number average molecular weight (Mn), and the amount of α-olefin used for ethylene during polymerization. , And its type. For example, when the amount of α-olefin used relative to ethylene is increased, the density of the resulting polymer can be lowered.

From the viewpoint of the density of the polyethylene wax, an ethylene homopolymer, a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms, or a mixture thereof is preferable.
The α-olefin used for producing the copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms is preferably an α-olefin having 3 to 10 carbon atoms, and propylene, 1-butene, 1-pentene. 1-hexene, 4-methyl-1-pentene and 1-octene are more preferable, and propylene, 1-butene, 1-hexene and 4-methyl-1-pentene are particularly preferable.

It is preferable that the α-olefin used in the production of the copolymer of ethylene and α-olefin is in the range of 0 to 20 mol% with respect to all monomers used.
The density of the polyethylene wax can also be controlled by the polymerization temperature. For example, when a polyethylene wax is produced by a metallocene catalyst described later, the polymerization temperature is usually in the range of 100 to 200 ° C., but from the viewpoint of producing a polyethylene wax having a density in the preferred range described above, the polymerization temperature is , Preferably, it is the range of 100-180 degreeC, More preferably, it is the range of 100-170 degreeC.

Such polyethylene wax is solid at normal temperature and becomes a low-viscosity liquid at 65 to 130 ° C.
Further, the polyethylene wax preferably has the crystallization temperature [Tc (° C.)] measured by a differential scanning calorimeter (DSC) and the density (D (kg / m ³ )) measured by the density gradient method. Formula (III) below
0.501 × D-366 ≧ Tc (III)
More preferably, the following formula (IIIa)
0.501 × D-366.5 ≧ Tc (IIIa)
More preferably, the following formula (IIIb)
0.501 × D-367 ≧ Tc (IIIb)
Satisfy the relationship.

  When the crystallization temperature (Tc) and the density (D) in the polyethylene wax satisfy the relationship of the above formula, the dispersibility of the polyethylene wax in polyethylene tends to be good.

  A polyethylene wax that satisfies the relationship of the above formula can be prepared using a metallocene catalyst. Among the metallocene catalysts, metallocene catalysts whose ligands are non-crosslinked are preferable. As such a metallocene catalyst, a metallocene compound represented by the general formula (1) described later can be exemplified.

  Furthermore, the polyethylene wax satisfying the relationship of the above formula can also be produced by controlling the polymerization temperature. For example, when a polyethylene wax is produced by a metallocene catalyst described later, the polymerization temperature is usually in the range of 100 to 200 ° C., but from the viewpoint of producing the polyethylene wax having the B value described above, the polymerization temperature is preferably Is in the range of 100 to 180 ° C, more preferably in the range of 100 to 170 ° C.

Suitable metallocene catalysts in the present invention include, for example,
(A) a metallocene compound of a transition metal selected from Group 4 of the periodic table, and (B) (b-1) an organoaluminum oxy compound,
(b-2) a compound that reacts with the bridged metallocene compound (A) to form an ion pair, and
(b-3) An olefin polymerization catalyst comprising at least one compound selected from organoaluminum compounds.

These will be described in detail below.
<Metalocene compounds>
(A) Metallocene compound of transition metal selected from Group 4 of the periodic table The metallocene compound forming the metallocene catalyst is a metallocene compound of transition metal selected from Group 4 of the periodic table. The compound represented by Formula (1) is mentioned.
M ¹ Lx (1)
Here, M ¹ is a transition metal selected from Group 4 of the periodic table, x is a valence of the transition metal M ¹ , and L is a ligand. Examples of the transition metal represented by M ¹ include zirconium, titanium, hafnium and the like. L is a ligand coordinated to the transition metal M ^1, and at least one of the ligands L is a ligand having a cyclopentadienyl skeleton, and the ligand having this cyclopentadienyl skeleton. The ligand may have a substituent. Examples of the ligand L having a cyclopentadienyl skeleton include a cyclopentadienyl group, a methylcyclopentadienyl group, an ethylcyclopentadienyl group, an n- or i-propylcyclopentadienyl group, n-, alkyl such as i-, sec- or t-butylcyclopentadienyl group, dimethylcyclopentadienyl group, methylpropylcyclopentadienyl group, methylbutylcyclopentadienyl group, methylbenzylcyclopentadienyl group, An alkyl-substituted cyclopentadienyl group; and an indenyl group, 4,5,6,7-tetrahydroindenyl group, a fluorenyl group, and the like. The hydrogen of the ligand having a cyclopentadienyl skeleton may be substituted with a halogen atom or a trialkylsilyl group.

  When the metallocene compound has two or more ligands having a cyclopentadienyl skeleton as the ligand L, the ligands having two cyclopentadienyl skeletons are ethylene, propylene. Or a substituted alkylene group such as isopropylidene or diphenylmethylene; a substituted silylene group such as a silylene group or a dimethylsilylene group, a diphenylsilylene group, or a methylphenylsilylene group.

Examples of ligands other than ligands having a cyclopentadienyl skeleton (ligands having no cyclopentadienyl skeleton) L include hydrocarbon groups having 1 to 12 carbon atoms, alkoxy groups, aryloxy groups, sulfones. Acid-containing group (—SO ₃ R ¹ ), halogen atom or hydrogen atom (where R ¹ is an alkyl group, an alkyl group substituted with a halogen atom, an aryl group, an aryl group substituted with a halogen atom, or an alkyl group) A substituted aryl group).

<Example 1 of metallocene compound>
When the metallocene compound represented by the general formula (1) has a transition metal valence of 4, for example, it is more specifically represented by the following general formula (2).
R ² _k R ³ _l R ⁴ _m R ⁵ _n M ¹ (2)
Here, M ¹ is a transition metal selected from Group 4 of the periodic table, R ² is a group (ligand) having a cyclopentadienyl skeleton, and R ³ , R ⁴ and R ⁵ are each independently cyclopentadienyl. A group (ligand) having or not having a skeleton. k is an integer of 1 or more, and k + l + m + n = 4.

Examples of metallocene compounds in which M ¹ is zirconium and contains at least two ligands having a cyclopentadienyl skeleton are given below. Bis (cyclopentadienyl) zirconium monochloride monohydride, bis (cyclopentadienyl) zirconium dichloride, bis (1-methyl-3-butylcyclopentadienyl) zirconium bis (trifluoromethanesulfonate), bis (1, 3-dimethylcyclopentadienyl) zirconium dichloride and the like.

Among the above compounds, compounds in which the 1,3-position substituted cyclopentadienyl group is replaced with a 1,2-position substituted cyclopentadienyl group can also be used.
Another example of the metallocene compound is R ² , R ³ , R ^{4 in the} general formula (2).
And at least two of R ⁵ , for example, R ² and R ³ are groups having a cyclopentadienyl skeleton (
A bridge type metallocene compound in which at least two groups are bonded via an alkylene group, a substituted alkylene group, a silylene group, a substituted silylene group, or the like. At this time, R ⁴ and R ⁵ are each independently the same as the ligand L other than the ligand having the cyclopentadienyl skeleton described above.

  Examples of such bridge-type metallocene compounds include ethylenebis (indenyl) dimethylzirconium, ethylenebis (indenyl) zirconium dichloride, isopropylidene (cyclopentadienyl-fluorenyl) zirconium dichloride, diphenylsilylenebis (indenyl) zirconium dichloride, methyl Examples include phenylsilylene bis (indenyl) zirconium dichloride.

<Example 2 of metallocene compound>
Moreover, as an example of a metallocene compound, the metallocene compound of Unexamined-Japanese-Patent No. 4-268307 represented by following General formula (3) is mentioned.

Here, M ¹ is a Group 4 transition metal of the periodic table, and specifically includes titanium, zirconium, and hafnium.
R ¹¹ and R ¹² may be the same or different from each other, and are a hydrogen atom; an alkyl group having 1 to 10 carbon atoms; an alkoxy group having 1 to 10 carbon atoms; an aryl group having 6 to 10 carbon atoms; Aryloxy group having 6 to 10 carbon atoms; alkenyl group having 2 to 10 carbon atoms; arylalkyl group having 7 to 40 carbon atoms; alkylaryl group having 7 to 40 carbon atoms; arylalkenyl group having 8 to 40 carbon atoms Or a halogen atom, and R ¹¹ and R ¹² are preferably chlorine atoms.

R ¹³ and R ¹⁴ may be the same or different from each other, and are a hydrogen atom; a halogen atom; an optionally halogenated alkyl group having 1 to 10 carbon atoms; an aryl group having 6 to 10 carbon atoms; (R ²⁰ ) ₂ , —SR ²⁰ , —OSi (R ²⁰ ) ₃ , —Si (R ²⁰ ) ₃ or —P (R ²⁰ ) ₂ groups. R ²⁰ is a halogen atom, preferably a chlorine atom; an alkyl group having 1 to 10 carbon atoms, preferably 1 to 3 carbon atoms; or an aryl group having 6 to 10 carbon atoms, preferably 6 to 8 carbon atoms. R ¹³ and R ¹⁴ are particularly preferably hydrogen atoms.

R ¹⁵ and R ¹⁶ are the same as R ¹³ and R ¹⁴ except that they do not contain a hydrogen atom, and may be the same or different from each other, preferably the same. R ¹⁵ and R ¹⁶ are preferably an optionally halogenated alkyl group having 1 to 4 carbon atoms, specifically, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, trifluoromethyl and the like. Particularly preferred is methyl.
In the general formula (3), R ¹⁷ is selected from the following group.

= BR ²¹ , = AlR ²¹ , -Ge-, -Sn-, -O-, -S-, = SO, = SO ₂ , = N
R ²¹ , = CO, = PR ²¹ , = P (O) R ^{21 and the} like. M ² is silicon, germanium or tin,
Silicon or germanium is preferred. Here, R ²¹ , R ²² and R ²³ may be the same or different from each other, and are hydrogen atom; halogen atom; alkyl group having 1 to 10 carbon atoms; fluoroalkyl group having 1 to 10 carbon atoms; carbon atom An aryl group having 6 to 10 carbon atoms; a fluoroaryl group having 6 to 10 carbon atoms; an alkoxy group having 1 to 10 carbon atoms; an alkenyl group having 2 to 10 carbon atoms; an arylalkyl group having 7 to 40 carbon atoms; An arylalkenyl group having 8 to 40 carbon atoms; or an alkylaryl group having 7 to 40 carbon atoms. “R ²¹ and R ²² ” or “R ²¹ and R ²³ ” may form a ring together with the atoms to which they are bonded. R ¹⁷ may be = CR ²¹ R ²² , = SiR ²¹ R ²² , = GeR ²¹ R ²² , -O-, -S-, = SO, = PR ²¹ or = P (O) R ^21. preferable. R ¹⁸ and R ¹⁹ may be the same as or different from each other, and examples thereof include the same as R ²¹ . m and n may be the same or different and are each 0, 1 or 2, preferably 0 or 1, and m + n is 0, 1 or 2, preferably 0 or 1.

Examples of the metallocene compound represented by the general formula (3) include the following compounds. rac-ethylene (2-methyl-1-indenyl) ₂ -zirconium dichloride,
rac-dimethylsilylene (2-methyl-1-indenyl) ₂ -zirconium dichloride and the like. These metallocene compounds can be produced, for example, by the method described in JP-A-4-268307.

<Example 3 of metallocene compound>
Moreover, as a metallocene compound, the metallocene compound represented by following General formula (4) can also be used.

In Formula (4), M ³ represents a transition metal atom of Group 4 of the periodic table, and specifically, titanium, zirconium, hafnium, and the like. R ²⁴ and R ²⁵ may be the same or different and are each a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a halogenated hydrocarbon group having 1 to 20 carbon atoms, a silicon-containing group, oxygen A containing group, a sulfur-containing group, a nitrogen-containing group or a phosphorus-containing group; R ²⁴ is preferably a hydrocarbon group, and particularly preferably an alkyl group having 1 to 3 carbon atoms such as methyl, ethyl or propyl. R ²⁵ is preferably a hydrogen atom or a hydrocarbon group, particularly preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms such as methyl, ethyl or propyl. R ²⁶ , R ²⁷ , R ²⁸ and R ²⁹ may be the same or different from each other, and are a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, or a halogenated hydrocarbon having 1 to 20 carbon atoms. Indicates a group. Among these, a hydrogen atom, a hydrocarbon group, or a halogenated hydrocarbon group is preferable. At least one of R ²⁶ and R ²⁷ , R ²⁷ and R ²⁸ , and R ²⁸ and R ²⁹ may form a monocyclic aromatic ring together with the carbon atoms to which they are bonded. Good. When there are two or more hydrocarbon groups or halogenated hydrocarbon groups other than the group forming the aromatic ring, they may be bonded to each other to form a ring. When R ²⁹ is a substituent other than an aromatic group, it is preferably a hydrogen atom. X ¹ and X ² may be the same or different from each other, and are a hydrogen atom, a halogen atom, or a carbon atom number of 1
Y representing 20 hydrocarbon group, halogenated hydrocarbon group having 1 to 20 carbon atoms, oxygen atom-containing group or sulfur atom-containing group is a divalent hydrocarbon group having 1 to 20 carbon atoms, the number of carbon atoms 1-20 divalent halogenated hydrocarbon groups, divalent silicon-containing groups, divalent germanium-containing groups, divalent tin-containing groups, -O-, -CO-, -S-, -SO-, ^{_{-SO 2 -, - NR 30 -}} , -
^{P (R 30) -, -} P (O) (R 30) -, - BR 30 - or -AlR ³⁰ - (provided that, R ³⁰ is a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, A halogenated hydrocarbon group having 1 to 20 carbon atoms).

In the formula (4), at least one pair of R ²⁶ and R ²⁷ , R ²⁷ and R ²⁸ , R ²⁸ and R ²⁹ is bonded to each other, and is coordinated to M ³ Examples of the ligand include those represented by the following formula.

(In the formula, Y is the same as that shown in the previous formula.)
<Example 4 of metallocene compound>
As the metallocene compound, a metallocene compound represented by the following general formula (5) can also be used.

In the formula (5), M ³ , R ²⁴ , R ²⁵ , R ²⁶ , R ²⁷ , R ²⁸ and R ²⁹ are the same as those in the general formula (4). Of R ²⁶ , R ²⁷ , R ²⁸ and R ²⁹ , two groups including R ²⁶ are preferably alkyl groups, and R ²⁶ and R ²⁸ , or R ²⁸ and R ²⁹ are alkyl groups. preferable. This alkyl group is preferably a secondary or tertiary alkyl group. The alkyl group may be substituted with a halogen atom or a silicon-containing group. Examples of the halogen atom and silicon-containing group include the substituents exemplified for R ²⁴ and R ²⁵ . Of R ²⁶ , R ²⁷ , R ²⁸ and R ²⁹ , the group other than the alkyl group is preferably a hydrogen atom. R ²⁶ , R ²⁷ , R ^28, and R ²⁹ may form a monocyclic ring or a polycyclic ring other than an aromatic ring by combining two groups selected from these groups. Examples of the halogen atom are the same as those described above for R ²⁴ and R ²⁵ . Examples of X ¹ , X ² and Y are the same as those described above.

Specific examples of the metallocene compound represented by the general formula (5) are shown below. rac-dimethylsilylene-bis (4,7-dimethyl-1-indenyl) zirconium dichloride, r
ac-dimethylsilylene-bis (2,4,7-trimethyl-1-indenyl) zirconium dichloride, rac-dimethylsilylene-bis (2,4,6-trimethyl-1-indenyl) zirconium dichloride, and the like.

  In these compounds, transition metal compounds in which zirconium metal is replaced with titanium metal or hafnium metal can also be used. The transition metal compound is usually used as a racemate, but can also be used in the R-type or S-type.

<Examples of metallocene compounds-5>
As the metallocene compound, a metallocene compound represented by the following general formula (6) can also be used.

In the formula (6), M ³ , R ²⁴ , X ¹ , X ² and Y are the same as those in the general formula (4). R ²⁴ is preferably a hydrocarbon group, particularly preferably an alkyl group having 1 to 4 carbon atoms such as methyl, ethyl, propyl or butyl. R ²⁵ represents an aryl group having 6 to 16 carbon atoms. R ²⁵ is preferably phenyl or naphthyl. The aryl group may be substituted with a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, or a halogenated hydrocarbon group having 1 to 20 carbon atoms. X ¹ and X ² are preferably a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms.

  Specific examples of the metallocene compound represented by the general formula (6) are shown below. rac-dimethylsilylene-bis (4-phenyl-1-indenyl) zirconium dichloride, rac-dimethylsilylene-bis (2-methyl-4-phenyl-1-indenyl) zirconium dichloride, rac-dimethylsilylene-bis (2-methyl) -4- (α-naphthyl) -1-indenyl) zirconium dichloride, rac-dimethylsilylene-bis (2-methyl-4- (β-naphthyl) -1-indenyl) zirconium dichloride, rac-dimethylsilylene-bis (2 -Methyl-4- (1-anthryl) -1-indenyl) zirconium dichloride and the like. In these compounds, transition metal compounds in which zirconium metal is replaced with titanium metal or hafnium metal can also be used.

<Examples of metallocene compounds-6>
As the metallocene compound, a metallocene compound represented by the following general formula (7) can also be used.
LaM ⁴ X ³ ₂ (7)
Here, M ⁴ is a periodic table group 4 or lanthanide series metal. La is a derivative of a delocalized π bond group, and is a group imparting a constraining geometry to the metal M ⁴ active site. X ³ may be the same or different from each other, and is a hydrogen atom, a halogen atom, a hydrocarbon group having 20 or less carbon atoms, a silyl group containing 20 or less silicon, or a germanyl group containing 20 or less germanium.
Among these compounds, a compound represented by the following formula (8) is preferable.

In the formula (8), M ⁴ is titanium, zirconium or hafnium. X ³ is the same as that described in the general formula (7). Cp is a substituted cyclopentadienyl group having a π bond to M ⁴ and having a substituent Z. Z is oxygen, sulfur, boron or an element belonging to Group 4 of the periodic table (for example, silicon, germanium or tin). Y is a ligand containing nitrogen, phosphorus, oxygen or sulfur, and Z and Y may form a condensed ring. Specific examples of the metallocene compound represented by the formula (8) are shown below. (Dimethyl (t-butylamide) (tetramethyl-η ⁵ -cyclopentadienyl) silane) titanium dichloride, ((t-butylamide) (tetramethyl-η ⁵ -cyclopentadienyl) -1,2-ethanediyl) titanium Dichloride etc. In the metallocene compound, a compound in which titanium is replaced with zirconium or hafnium can be exemplified.

<Examples of metallocene compounds-7>
Moreover, as a metallocene compound, the metallocene compound represented by following General formula (9) can also be used.

In formula (9), M ³ is a transition metal atom of Group 4 of the periodic table, specifically titanium, zirconium or hafnium, preferably zirconium. R ³¹ may be the same as or different from each other, and at least one of them is an aryl group having 11 to 20 carbon atoms, an arylalkyl group having 12 to 40 carbon atoms, an arylalkenyl group having 13 to 40 carbon atoms, carbon An alkylaryl group having 12 to 40 atoms or a silicon-containing group, or at least two adjacent groups among the groups represented by R ³¹ , together with the carbon atoms to which they are bonded, one or more aromatic rings Or an aliphatic ring is formed. In this case, the ring formed by R ^31, it is 4 to 20 carbon atoms in all including carbon atoms to which R ³¹ is bonded. Aryl group, arylalkyl group, arylalkenyl group, an alkylaryl group and an aromatic ring, R ³¹ other than R ³¹ that forms an aliphatic ring is a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms Or a silicon-containing group. R ³² may be the same as or different from each other, and may be a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, or a carbon atom. An arylalkyl group having 7 to 40 carbon atoms, an arylalkenyl group having 8 to 40 carbon atoms, an alkylaryl group having 7 to 40 carbon atoms, a silicon-containing group, an oxygen-containing group, a sulfur-containing group, a nitrogen-containing group or a phosphorus-containing group It is. Further, at least two adjacent groups among the groups represented by R ³² may form one or more aromatic rings or aliphatic rings together with the carbon atoms to which they are bonded. In this case, the ring formed by R ³² has 4 to 20 carbon atoms in all including carbon atoms to which R ³² is bonded, an aromatic ring, other than R ³² that forms an aliphatic ring R ³² is a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, or a silicon-containing group. The group in which the two groups represented by R ^{32 form} one or more aromatic rings or aliphatic rings includes an embodiment in which the fluorenyl group has a structure represented by the following formula.

R ³² is preferably a hydrogen atom or an alkyl group, and particularly preferably a hydrogen atom or a hydrocarbon group having 1 to 3 carbon atoms such as methyl, ethyl or propyl. A suitable example of such a fluorenyl group having R ³² as a substituent is a 2,7-dialkyl-fluorenyl group. In this case, the 2,7-dialkyl alkyl group includes 1 to 1 carbon atoms. 5 alkyl groups. R ³¹ and R ³² may be the same as or different from each other. R ³³ and R ³⁴ may be the same as or different from each other, and are the same hydrogen atom, halogen atom, alkyl group having 1 to 10 carbon atoms, aryl group having 6 to 20 carbon atoms, and 2 to 2 carbon atoms. 10 alkenyl groups, arylalkyl groups having 7 to 40 carbon atoms, arylalkenyl groups having 8 to 40 carbon atoms, alkylaryl groups having 7 to 40 carbon atoms, silicon-containing groups, oxygen-containing groups, sulfur-containing groups, A nitrogen-containing group or a phosphorus-containing group. Of these, at least one of R ³³ and R ³⁴ is preferably an alkyl group having 1 to 3 carbon atoms. X ¹ and X ² may be the same or different and are each a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a halogenated hydrocarbon group having 1 to 20 carbon atoms, an oxygen-containing group, sulfur A conjugated diene residue formed from a containing group or a nitrogen-containing group, or X ¹ and X ² . As the conjugated diene residue formed from X ¹ and X ² , residues of 1,3-butadiene, 2,4-hexadiene, 1-phenyl-1,3-pentadiene and 1,4-diphenylbutadiene are preferable. These residues may be further substituted with a hydrocarbon group having 1 to 10 carbon atoms. X ¹ and X ² are preferably a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, or a sulfur-containing group. Y 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, a divalent germanium-containing group, a divalent Tin-containing group, —O—, —CO—, —S—, —SO—, —SO ₂ —, —N
^{R 35 -, - P (R} 35) -, - P (O) (R 35) -, - BR 35 - or -AlR ³⁵ - (provided that, R ³⁵ is a hydrogen atom, a halogen atom, carbon atom 20 And a halogenated hydrocarbon group having 1 to 20 carbon atoms). Among these divalent groups, those in which the shortest linking portion of -Y- is composed of one or two atoms are preferable. R ³⁵ is a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, or a halogenated hydrocarbon group having 1 to 20 carbon atoms. Y is preferably a divalent hydrocarbon group having 1 to 5 carbon atoms, a divalent silicon-containing group or a divalent germanium-containing group, more preferably a divalent silicon-containing group. Particularly preferred is silylene, alkylarylsilylene or arylsilylene.

<Examples of metallocene compounds-8>
As the metallocene compound, a metallocene compound represented by the following general formula (10) can also be used.

In formula (10), M ³ is a transition metal atom of Group 4 of the periodic table, specifically titanium, zirconium or hafnium, preferably zirconium. R ³⁶ may be the same as or different from each other, and includes a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, and silicon-containing Group, oxygen-containing group, sulfur-containing group, nitrogen-containing group or phosphorus-containing group. The alkyl group and alkenyl group may be substituted with a halogen atom. Of these, R ³⁶ is preferably an alkyl group, an aryl group or a hydrogen atom, particularly a hydrocarbon group having 1 to 3 carbon atoms such as methyl, ethyl, n-propyl and i-propyl, phenyl, α-naphthyl. And an aryl group such as β-naphthyl or a hydrogen atom. R ³⁷ may be the same or different from each other, and may be a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, or a carbon atom. An arylalkyl group having 7 to 40 carbon atoms, an arylalkenyl group having 8 to 40 carbon atoms, an alkylaryl group having 7 to 40 carbon atoms, a silicon-containing group, an oxygen-containing group, a sulfur-containing group, a nitrogen-containing group or a phosphorus-containing group It is. Note that the alkyl group, aryl group, alkenyl group, arylalkyl group, arylalkenyl group, and alkylaryl group may be substituted with halogen. Of these, R ³⁷ is preferably a hydrogen atom or an alkyl group, and particularly a hydrogen atom or a carbon atom having 1 to 4 carbon atoms such as methyl, ethyl, n-propyl, i-propyl, n-butyl, or tert-butyl. A hydrogen group is preferred. R ³⁶ and R ³⁷ may be the same as or different from each other. One of R ³⁸ and R ³⁹ is an alkyl group having 1 to 5 carbon atoms, and the other is a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkenyl group having 2 to 10 carbon atoms. A silicon-containing group, an oxygen-containing group, a sulfur-containing group, a nitrogen-containing group or a phosphorus-containing group. Among these, it is preferable that any one of R ³⁸ and R ³⁹ is an alkyl group having 1 to 3 carbon atoms such as methyl, ethyl, and propyl, and the other is a hydrogen atom. X ¹ and X ² may be the same or different and are each a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a halogenated hydrocarbon group having 1 to 20 carbon atoms, an oxygen-containing group, sulfur A conjugated diene residue formed from a containing group or a nitrogen-containing group, or X ¹ and X ² . Among these, a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms is preferable. Y 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, a divalent germanium-containing group, a divalent tin-containing group, -O -, - CO -, - S -, - SO -, - SO 2 -, - NR 40 -, - P (R 40) -,
—P (O) (R ⁴⁰ ) —, —BR ⁴⁰ — or —AlR ⁴⁰ — (wherein R ⁴⁰ is a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, or a group having 1 to 20 carbon atoms. A halogenated hydrocarbon group). Among these, Y is preferably a divalent hydrocarbon group having 1 to 5 carbon atoms, a divalent silicon-containing group, or a divalent germanium-containing group, and more preferably a divalent silicon-containing group. An alkylsilylene, an alkylarylsilylene or an arylsilylene is particularly preferable.

<Examples of metallocene compounds-9>
Further, as the metallocene compound, a metallocene compound represented by the following general formula (11) can also be used.

In the formula (11), Y is selected from carbon, silicon, germanium and tin atoms, M is Ti, Zr or Hf, and R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ and R ¹²
Are selected from hydrogen, a hydrocarbon group, and a silicon-containing group, and may be the same or different, and adjacent substituents from R ⁵ to R ¹² may be bonded to each other to form a ring, R ¹³ , R ¹⁴ is selected from a hydrocarbon group and a silicon-containing group, and may be the same or different, and R ¹³ and R ¹⁴ may be bonded to each other to form a ring. Q may be selected from a halogen, a hydrocarbon group, an anionic ligand, or a neutral ligand capable of coordinating with a lone electron pair in the same or different combination, and j is an integer of 1 to 4. )
Hereinafter, after describing sequentially the cyclopentadienyl group, the fluorenyl group, the crosslinked part, and other characteristics that are the chemical structure characteristics of the bridged metallocene compound according to the present invention, a preferable bridged metallocene compound having these characteristics will be described. .

Cyclopentadienyl group The cyclopentadienyl group may or may not be substituted. The cyclopentadienyl group which may or may not be substituted means that R ¹ , R ² , R ³ and R ⁴ possessed by the cyclopentadienyl group moiety in the general formula (11) are all hydrogen atoms. Or any one or more of R ¹ , R ² , R ³ and R ⁴ is a hydrocarbon group (f1), preferably a hydrocarbon group having 1 to 20 carbon atoms (f1 ′), or silicon-containing It means a cyclopentadienyl group substituted by a group (f2), preferably a silicon-containing group (f2 ′) having a total carbon number of 1 to 20. When two or more of R ¹ , R ² , R ³ and R ⁴ are substituted, these substituents may be the same as or different from each other. Further, the hydrocarbon group having 1 to 20 carbon atoms in total is an alkyl, alkenyl, alkynyl, or aryl group composed of only carbon and hydrogen. These include those in which any two adjacent hydrogen atoms are simultaneously substituted to form an alicyclic or aromatic ring. The hydrocarbon group having 1 to 20 carbon atoms in total (f1 ′) includes, in addition to alkyl, alkenyl, alkynyl and aryl groups composed only of carbon and hydrogen, some of the hydrogen atoms directly connected to these carbon atoms are halogen atoms. , An oxygen-containing group, a nitrogen-containing group, a heteroatom-containing hydrocarbon group substituted with a silicon-containing group, or a group in which any two adjacent hydrogen atoms form an alicyclic group. Such a group (f1 ')
As, methyl group, ethyl group, n-propyl group, allyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, linear hydrocarbon group such as n-decanyl group; isopropyl group, t-butyl group, amyl group, 3-methylpentyl group, 1,1-diethylpropyl group, 1,1-dimethylbutyl group, 1-methyl- Branched hydrocarbon groups such as 1-propylbutyl group, 1,1-propylbutyl group, 1,1-dimethyl-2-methylpropyl group, 1-methyl-1-isopropyl-2-methylpropyl group; cyclopentyl group, Cyclic saturated hydrocarbon groups such as cyclohexyl group, cycloheptyl group, cyclooctyl group, norbornyl group, adamantyl group; cyclic unsaturated hydrocarbon groups such as phenyl group, naphthyl group, biphenyl group, phenanthryl group, anthracenyl group and their nuclei Alkyl substitution A saturated hydrocarbon group substituted with an aryl group such as benzyl group or cumyl group; methoxy group, ethoxy group, phenoxy group, N-methylamino group, trifluoromethyl group, tribromomethyl group, pentafluoroethyl group, pentafluorophenyl And a heteroatom-containing hydrocarbon group such as a group.
The silicon-containing group (f2) is, for example, a group in which a ring carbon of a cyclopentadienyl group is directly covalently bonded to a silicon atom, and specifically an alkylsilyl group or an arylsilyl group. Examples of the silicon-containing group (f2 ′) having a total carbon number of 1 to 20 include a trimethylsilyl group and a triphenylsilyl group.

Fluorenyl group The fluorenyl group may or may not be substituted. The fluorenyl group which may or may not be substituted is R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ and R ¹² possessed by the fluorenyl group moiety in the general formula (11). Are all hydrogen atoms, or at least one of R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ and R ¹² is a hydrocarbon group (f1), preferably Total carbon number 1 to 2
It means a fluorenyl group substituted with 0 hydrocarbon group (f1 ′) or silicon-containing group (f2), preferably a silicon-containing group (f2 ′) having 1 to 20 carbon atoms in total. When two or more of R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ and R ¹² are substituted, the substituents may be the same or different from each other. Good. Further, R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ and R ¹² may be bonded to each other to form a ring. In view of the ease of production of the catalyst, those in which R ⁶ and R ¹¹ and R ⁷ and R ¹⁰ are the same are preferably used.
A preferred group of the hydrocarbon group (f1) is the above-described hydrocarbon group (f1 ′) having a total carbon number of 1 to 20, and a preferable example of the silicon-containing group (f2) is the above-described total number of carbon atoms of 1 to 20. It is a silicon-containing group (f2 ′).

Covalent bond bridge The main chain part of the bond connecting the cyclopentadienyl group and the fluorenyl group is a divalent covalent bond containing one carbon, silicon, germanium and tin atom. The important point in the high-temperature solution polymerization of the present invention is that the bridging atom Y of the covalent bond bridging portion has R ¹³ and R ¹⁴ which may be the same or different from each other. A preferred group of the hydrocarbon group (f1) is the above-described hydrocarbon group (f1 ′) having a total carbon number of 1 to 20, and a preferable example of the silicon-containing group (f2) is the above-described total number of carbon atoms of 1 to 20. It is a silicon-containing group (f2 ′).

Other characteristics of the bridged metallocene compound In the general formula (11), Q is halogen, a hydrocarbon group having 1 to 10 carbon atoms, or a neutral, conjugated or nonconjugated diene having 10 or less carbon atoms, They are selected from the same or different combinations from anionic ligands or neutral ligands that can coordinate with a lone pair of electrons. Specific examples of the halogen are fluorine, chlorine, bromine and iodine, and specific examples of the hydrocarbon group are methyl, ethyl, n-propyl, isopropyl, 2-methylpropyl, 1,1-dimethylpropyl, 2, 2-dimethylpropyl, 1,1-diethylpropyl, 1-ethyl-1-methylpropyl, 1,1,2,2-tetramethylpropyl, sec-butyl, tert-butyl, 1,1-dimethylbutyl, 1, Examples include 1,3-trimethylbutyl, neopentyl, cyclohexylmethyl, cyclohexyl, 1-methyl-1-cyclohexyl and the like. Specific examples of neutral, conjugated or non-conjugated dienes having 10 or less carbon atoms include s-cis-
Or s- trans eta ⁴ -1,3-butadiene, s- cis - or s- trans eta ^{4-1,4-diphenyl-1,3-butadiene,} s- cis - or s- trans eta ⁴ - 3-methyl-1,3-pentadiene, s-cis- or s-trans-η ⁴ -1,4-dibenzyl-1,3-butadiene, s-cis- or s-trans-η ⁴ -2,4- Hexadiene, s-cis- or s-trans-η ⁴ -1,3-pentadiene, s-cis- or s-trans-η ⁴ -1,4-ditolyl-1,3-butadiene, s-cis- or s -Trans-η ⁴ -1,4-bis (trimethylsilyl) -1,3-butadiene and the like. Specific examples of the anionic ligand include alkoxy groups such as methoxy, tert-butoxy and phenoxy, carboxylate groups such as acetate and benzoate, and sulfonate groups such as mesylate and tosylate. Specific examples of neutral ligands that can be coordinated by a lone pair include organophosphorus compounds such as trimethylphosphine, triethylphosphine, triphenylphosphine, diphenylmethylphosphine, tetrahydrofuran, diethyl ether, dioxane, 1,2- And ethers such as dimethoxyethane. j is an integer of 1 to 4, and when j is 2 or more, Qs may be the same or different from each other.

<Example of metallocene compound-10>
Moreover, as a metallocene compound, the metallocene compound represented by the following general formula (12) can also be used.

In the formula, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹³ , R ¹⁴ are hydrogen or a hydrocarbon group Selected from silicon-containing groups, which may be the same or different, and adjacent substituents from R ¹ to R ¹⁴ may be bonded to each other to form a ring, and M represents Ti, Zr
Or Hf, Y is a Group 14 atom, Q can be coordinated by halogen, hydrocarbon group, neutral having 10 or less carbon atoms, conjugated or non-conjugated diene, anionic ligand, and lone pair of electrons Selected from the group consisting of neutral ligands in the same or different combinations, n is an integer of 2 to 4, and j is an integer of 1 to 4.

  In the general formula (12), the hydrocarbon group is preferably an alkyl group having 1 to 20 carbon atoms, an arylalkyl group having 7 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or 7 to 20 carbon atoms. And may contain one or more ring structures.

Specific examples thereof include methyl, ethyl, n-propyl, isopropyl, 2-methylpropyl, 1,1-dimethylpropyl, 2,2-dimethylpropyl, 1,1-diethylpropyl, 1-ethyl-1-
Methylpropyl, 1,1,2,2-tetramethylpropyl, sec-butyl, tert-butyl, 1,1-dimethylbutyl, 1,1,3-trimethylbutyl, neopentyl, cyclohexylmethyl, cyclohexyl, 1-methyl- 1-cyclohexyl, 1-adamantyl, 2-adamantyl, 2-methyl-2-adamantyl, menthyl, norbornyl, benzyl, 2-phenylethyl, 1-tetrahydronaphthyl, 1-methyl-1-tetrahydronaphthyl, phenyl, naphthyl, tolyl Etc.

  In the general formula (12), the silicon-containing hydrocarbon group is preferably an alkyl or arylsilyl group having 1 to 4 silicon atoms and 3 to 20 carbon atoms. Specific examples thereof include trimethylsilyl and tert-butyldimethyl. Examples thereof include silyl and triphenylsilyl.

In the present invention, R ¹ to R ^{14 in} the general formula (12) are selected from hydrogen, a hydrocarbon group, and a silicon-containing hydrocarbon group, and may be the same or different. Specific examples of preferred hydrocarbon groups and silicon-containing hydrocarbon groups include the same as those described above.

The adjacent substituents from R ¹ to R ¹⁴ on the cyclopentadienyl ring of the general formula (12) may be bonded to each other to form a ring.
M in the general formula (12) is a group 4 element of the periodic table, that is, zirconium, titanium or hafnium, preferably zirconium.

Y is a Group 14 atom, preferably a carbon atom or a silicon atom. n is an integer of 2 to 4, preferably 2 or 3, particularly preferably 2.
Q is the same or different combination from the group consisting of halogen, hydrocarbon group, neutral having 10 or less carbon atoms, conjugated or non-conjugated diene, anionic ligand and neutral ligand capable of coordinating with a lone pair. To be elected. When Q is a hydrocarbon group, it is more preferably a hydrocarbon group having 1 to 10 carbon atoms.

Specific examples of the halogen are fluorine, chlorine, bromine and iodine, and specific examples of the hydrocarbon group are methyl, ethyl, n-propyl, isopropyl, 2-methylpropyl, 1,1-dimethylpropyl, 2, 2-dimethylpropyl, 1,1-diethylpropyl, 1-ethyl-1-methylpropyl, 1,1,2,2-tetramethylpropyl, sec-butyl, tert-butyl, 1,1-dimethylbutyl, 1, Examples include 1,3-trimethylbutyl, neopentyl, cyclohexylmethyl, cyclohexyl, 1-methyl-1-cyclohexyl and the like. Neutral having 10 or less carbon atoms, and specific examples of the conjugated or non-conjugated dienes, s- cis - or s- trans eta ^{4-1,3-butadiene,} s- cis - or s- trans eta ⁴ - 1,4-diphenyl-1,3-butadiene, s-cis- or s-trans-η ⁴ -3-methyl-1,3-pentadiene, s-cis- or s-trans-η ⁴ -1,4- Dibenzyl-1,3-butadiene, s-cis- or s-trans-η ⁴ -2,4-hexadiene, s-cis- or s-trans-η ⁴ -1,3-pentadiene, s-cis- or s -Trans-η ⁴ -1,4-ditolyl-1,3-butadiene, s-cis- or s-trans-η ⁴ -1,4-bis (trimethylsilyl) -1,3-butadiene and the like. Specific examples of the anionic ligand include alkoxy groups such as methoxy, tert-butoxy and phenoxy, carboxylate groups such as acetate and benzoate, and sulfonate groups such as mesylate and tosylate. Specific examples of the neutral ligand that can coordinate with a lone electron pair include organic phosphorus compounds such as trimethylphosphine, triethylphosphine, triphenylphosphine, and diphenylmethylphosphine, or tetrahydrofuran, diethyl ether, dioxane, 1,2- And ethers such as dimethoxyethane. When j is an integer greater than or equal to 2, several Q may be the same or different.

In the formula (12), there are a plurality of Ys of 2 to 4, but the Ys may be the same as or different from each other. The plurality of R ¹³ and the plurality of R ¹⁴ bonded to Y may be the same as or different from each other. For example, a plurality of R ¹³ bonded to the same Y may be different from each other, or a plurality of R ¹³ bonded to different Y may be the same as each other. R ¹³ or R ¹⁴ may form a ring.

  Preferable examples of the Group 4 transition metal compound represented by the formula (12) include a compound represented by the following formula (13).

In formula (13), R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² are hydrogen atoms, hydrocarbon groups, silicon R ¹³ , R ¹⁴ , R ¹⁵ , and R ¹⁶ are each a hydrogen atom or a hydrocarbon group, n is an integer of 1 to 3, and n = 1 In some cases, R ¹ to R ¹⁶ are not hydrogen atoms and may be the same or different. Adjacent substituents from R ⁵ to R ¹² may combine with each other to form a ring, and R
¹³ and R ¹⁵ may be bonded to each other to form a ring, and R ¹³ and R ¹⁵ may be bonded to each other to form a ring, and at the same time, R ¹⁴ and R ¹⁶ may be bonded to each other to form a ring. , Y ¹ and Y ² are group 14 atoms which may be the same or different from each other, M is Ti, Zr or Hf, Q is a halogen, a hydrocarbon group, an anionic ligand or a lone pair of electrons You may choose from the neutral ligand which can be coordinated by the same or different combination, and j is an integer of 1-4.
Examples of such metallocene compounds such as Examples-9 and 10 are listed in JP-A No. 2004-175707, WO2001 / 027124, WO2004 / 029062, WO2004 / 083265, and the like.

  The metallocene compounds described above are used alone or in combination of two or more. The metallocene compound may be diluted with a hydrocarbon or a halogenated hydrocarbon.

The catalyst component comprises (A) the bridged metallocene compound represented above, and (B) (b-1) an organoaluminum oxy compound, (b-2) reacts with the bridged metallocene compound (A) to form an ion pair. And at least one compound selected from (b-3) organoaluminum compounds.

Hereinafter, the component (B) will be specifically described.
<(B-1) Organoaluminum oxy compound>
As the (b-1) organoaluminum oxy compound used in the present invention, a conventionally known aluminoxane can be used as it is. Specifically, the following general formula (14)

  And / or general formula (15)

(Wherein R represents a hydrocarbon group having 1 to 10 carbon atoms, and n represents an integer of 2 or more). In particular, R is a methylaluminoxane in which methyl is a methyl group, and n is 3 More preferably, 10 or more are used. These aluminoxanes may be mixed with some organoaluminum compounds. A characteristic property in the high temperature solution polymerization of the present invention is that a benzene-insoluble organoaluminum oxy compound as exemplified in JP-A-2-78687 can also be applied. Further, organoaluminum oxy compounds described in JP-A-2-167305, aluminoxanes having two or more types of alkyl groups described in JP-A-2-24701, JP-A-3-103407, and the like It can be suitably used. The “benzene-insoluble” organoaluminum oxy compound used in the high-temperature solution polymerization of the present invention means that the Al component dissolved in benzene at 60 ° C. is usually 10% or less, preferably 5% or less, particularly preferably 5% or less. Is 2% or less, and is insoluble or hardly soluble in benzene.

  Examples of the organoaluminum oxy compound used in the present invention include modified methylaluminoxane as shown in (16) below.

(Here, R represents a hydrocarbon group having 1 to 10 carbon atoms, and m and n represent an integer of 2 or more.)
This modified methylaluminoxane is prepared using trimethylaluminum and an alkylaluminum other than trimethylaluminum. Such a compound [V] is generally called MMAO. Such MMAO can be prepared by the methods listed in US4960878 and US5041584. In addition, Tosoh Finechem Co., Ltd., etc., which are prepared using trimethylaluminum and triisobutylaluminum and whose R is an isobutyl group, are commercially produced under the names MMAO and TMAO. Such MMAO is an aluminoxane having improved solubility in various solvents and storage stability, and specifically, it is different from those insoluble or hardly soluble in benzene such as the above (14) and (15). It is soluble in aliphatic hydrocarbons and alicyclic hydrocarbons.

Further, the organoaluminum oxy compound used in the present invention includes the following general formula (1
An organoaluminum oxy compound containing boron represented by 7) can also be mentioned.

(In the formula, R ^c represents a hydrocarbon group having 1 to 10 carbon atoms. R ^d may be the same or different and each represents a hydrogen atom, a halogen atom or a hydrocarbon having 1 to 10 carbon atoms. Group.)
<(B-2) Compound that reacts with bridged metallocene compound (A) to form an ion pair>
Examples of the compound (b-2) that reacts with the bridged metallocene compound (A) to form an ion pair (hereinafter sometimes abbreviated as “ionic compound”) include JP-A-1-501950, Lewis acids and ionic properties described in 1-502036, JP-A-3-17905, JP-A-3-179006, JP-A-3-207703, JP-A-3-207704, USP5321106, etc. Examples thereof include compounds, borane compounds and carborane compounds. Furthermore, heteropoly compounds and isopoly compounds can also be mentioned.
In the present invention, the ionic compound preferably employed is a compound represented by the following general formula (18).

In the formula, R ^{e +} includes H ⁺ , carbenium cation, oxonium cation, ammonium cation, phosphonium cation, cycloheptyltrienyl cation, ferrocenium cation having a transition metal, and the like. R ^{f to} R ⁱ may be the same as or different from each other, and are organic groups, preferably aryl groups.

  Specific examples of the carbenium cation include trisubstituted carbenium cations such as triphenylcarbenium cation, tris (methylphenyl) carbenium cation, and tris (dimethylphenyl) carbenium cation.

  Specific examples of the ammonium cation include trialkylammonium cations such as trimethylammonium cation, triethylammonium cation, tri (n-propyl) ammonium cation, triisopropylammonium cation, tri (n-butyl) ammonium cation, and triisobutylammonium cation. N, N-dimethylanilinium cation, N, N-diethylanilinium cation, N, N-2,4,6-pentamethylanilinium cation, etc., N, N-dialkylanilinium cation, diisopropylammonium cation, dicyclohexyl And dialkyl ammonium cations such as ammonium cations.

  Specific examples of the phosphonium cation include triarylphosphonium cations such as triphenylphosphonium cation, tris (methylphenyl) phosphonium cation, and tris (dimethylphenyl) phosphonium cation.

Of these, Re ^{e +} is preferably a carbenium cation, an ammonium cation or the like, and particularly preferably a triphenylcarbenium cation, an N, N-dimethylanilinium cation or an N, N-diethylanilinium cation.

Specific examples of the carbenium salt include triphenylcarbenium tetraphenylborate, triphenylcarbeniumtetrakis (pentafluorophenyl) borate, triphenylcarbeniumtetrakis (3,5-ditrifluoromethylphenyl) borate, tris (4-methyl And phenyl) carbenium tetrakis (pentafluorophenyl) borate and tris (3,5-dimethylphenyl) carbenium tetrakis (pentafluorophenyl) borate.

Examples of ammonium salts include trialkyl-substituted ammonium salts, N, N-dialkylanilinium salts, dialkylammonium salts, and the like.
Specific examples of the trialkyl-substituted ammonium salt include triethylammonium tetraphenylborate, tripropylammonium tetraphenylborate, tri (n-
Butyl) ammonium tetraphenylborate, trimethylammonium tetrakis (p-tolyl) borate, trimethylammonium tetrakis (o-tolyl) borate, tri (n-butyl) ammonium tetrakis (pentafluorophenyl) borate, triethylammonium tetrakis (pentafluorophenyl) Borate, tripropylammonium tetrakis (
Pentafluorophenyl) borate, tripropylammonium tetrakis (2,4-dimethylphenyl) borate, tri (n-butyl) ammonium tetrakis (3,5-dimethylphenyl) borate, tri (n-butyl) ammonium tetrakis (4-tri Fluoromethylphenyl) borate, tri (n-butyl) ammonium tetrakis (3,5-ditrifluoromethylphenyl) borate, tri (n-butyl) ammonium tetrakis (o-tolyl) borate, dioctadecylmethylammonium tetraphenylborate, di Octadecylmethylammonium tetrakis (p-tolyl) borate, dioctadecylmethylammonium tetrakis (o-tolyl) borate, dioctadecylmethylammonium tetrakis (pentafluorophenyl) borate, dioctadecylmethylammonium tetrakis (2,4-dimethyl) Tilphenyl) borate, dioctadecylmethylammonium tetrakis (3,5-dimethylphenyl) borate, dioctadecylmethylammonium tetrakis (4-trifluoromethylphenyl) borate, dioctadecylmethylammonium tetrakis (3,5-ditrifluoromethylphenyl) borate And dioctadecylmethylammonium.

Specific examples of N, N-dialkylanilinium salts include N, N-dimethylanilinium tetraphenylborate, N, N-dimethylanilinium tetrakis (pentafluorophenyl) borate, N, N-dimethylanilinium tetrakis ( 3,5-ditrifluoromethylphenyl) borate, N, N-diethylanilinium tetraphenylborate, N, N-diethylanilinium tetrakis (pentafluorophenyl) borate, N, N-diethylanilinium tetrakis (3,5- Ditrifluoromethylphenyl) borate, N, N-2,4,6-pentamethylanilinium tetraphenylborate, N, N-2,4,6-pentamethylanilinium tetrakis (pentafluorophenyl) borate, etc. .

  Specific examples of the dialkylammonium salt include di (1-propyl) ammonium tetrakis (pentafluorophenyl) borate and dicyclohexylammonium tetraphenylborate.

In addition, ionic compounds disclosed by the present applicant (Japanese Patent Laid-Open No. 2004-51676) can also be used without limitation.
The ionic compound (b-2) as described above can be used as a mixture of two or more.

<(B-3) Organoaluminum compound>
Examples of the organoaluminum compound that forms the olefin polymerization catalyst (b-3) include, for example, an organoaluminum compound represented by the following general formula [X], a group 1 metal represented by the following general formula (19), and aluminum. Examples thereof include complex alkylated products.
R ^a _m Al (OR ^b ) _n H _p X _q ------ (19)
(In the formula, R ^a and R ^b may be the same or different from each other, each represents a hydrocarbon group having 1 to 15 carbon atoms, preferably 1 to 4 carbon atoms, X represents a halogen atom, and m represents 0. <M ≦ 3, n is 0 ≦ n <3, p is a number of 0 ≦ p <3, q is a number of 0 ≦ q <3, and m + n + p + q = 3). Specific examples of such compounds include tri-n-alkylaluminums such as trimethylaluminum, triethylaluminum, tri-n-butylaluminum, trihexylaluminum, trioctylaluminum; triisopropylaluminum, triisobutylaluminum, trisec-butylaluminum, Tri-tert-butylaluminum,
Tri-branched alkylaluminums such as tri-2-methylbutylaluminum, tri-3-methylhexylaluminum, tri-2-ethylhexylaluminum; tricycloalkylaluminums such as tricyclohexylaluminum and tricyclooctylaluminum; triphenylaluminum, tritolylaluminum, etc. triaryl aluminum; diisopropyl aluminum hydride, dialkylaluminum hydride such as diisobutylaluminum hydride; formula _{(iC 4 H 9) x Al} y (C 5 H 10) z ( wherein, x, y, z are positive numbers Yes, z ≦ 2x.)
Alkenyl aluminum alkoxide such as isobutylaluminum methoxide and isobutylaluminum ethoxide; Dialkylaluminum alkoxide such as dimethylaluminum methoxide, diethylaluminum ethoxide and dibutylaluminum butoxide; Alkyl aluminum sesquialkoxides such as ethoxide and butylaluminum sesquibutoxide; partially alkoxylated alkylaluminums having an average composition represented by the general formula R ^a _2.5 Al (OR ^b ) _{0.5 and the} like; diethylaluminum phenoxide and diethylaluminum Alkyl aluminum aryloxides such as (2,6-di-t-butyl-4-methylphenoxide); dimethylal Dialkylaluminum halides such as nium chloride, diethylaluminum chloride, dibutylaluminum chloride, diethylaluminum bromide, diisobutylaluminum chloride; alkylaluminum sesquichlorides such as ethylaluminum sesquichloride, butylaluminum sesquichloride, ethylaluminum sesquibromide; Partially halogenated alkylaluminums such as alkylaluminum dihalides; dialkylaluminum hydrides such as diethylaluminum hydride and dibutylaluminum hydride; alkylaluminum dihydrides such as ethylaluminum dihydride and propylaluminum dihydride and other partially Hydrogenated alk Aluminum; ethylaluminum ethoxy chloride, butyl aluminum butoxide cycloalkyl chloride, etc. partially alkoxylated and halogenated alkylaluminum such as ethylaluminum ethoxy bromide and the like.
M ² AlR ^a ₄ ----------- (20)
(In the formula, M ² represents Li, Na or K, and R ^a represents a hydrocarbon group having 1 to 15 carbon atoms, preferably 1 to 4 carbon atoms.)
A complex alkylated product of a group 1 metal and aluminum in the periodic table represented by: Examples of such a compound include LiAl (C ₂ H ₅ ) ₄ and LiAl (C ₇ H ₁₅ ) ₄ .

A compound similar to the compound represented by the general formula (20) can also be used, and examples thereof include an organoaluminum compound in which two or more aluminum compounds are bonded through a nitrogen atom. Specifically, as such a compound, (C ₂ H ₅ ) ₂ AlN (C ₂ H ₅ ) Al (C ₂ H ₅ ) ₂
And so on.
From the viewpoint of availability, trimethylaluminum and triisobutylaluminum are preferably used as the (b-3) organoaluminum compound.

<Polymerization>
The polyethylene wax used in the present invention can be obtained by homopolymerizing ethylene in a normal liquid phase or copolymerizing ethylene and an α-olefin in the presence of the metallocene catalyst. In the polymerization, the method of using each component and the order of addition are arbitrarily selected, and the following methods are exemplified.

[q1] A method of adding the component (A) alone to the polymerization vessel.
[q2] A method of adding the component (A) and the component (B) to the polymerization vessel in an arbitrary order.
In the method [q2], at least two or more of the catalyst components may be in contact with each other in advance. At this time, a hydrocarbon solvent is generally used, but an α-olefin may be used as a solvent. The monomers used here are as described above.

  The polymerization methods include suspension polymerization in which polyethylene wax is polymerized in the presence of particles in a solvent such as hexane, gas phase polymerization in which no solvent is used, and at a polymerization temperature of 140 ° C. or higher, polyethylene wax is mixed with the solvent. Solution polymerization that polymerizes in the coexistence or melted state is possible, and among these, solution polymerization is preferable in terms of both economy and quality.

The polymerization reaction may be performed by either a batch method or a continuous method. When the polymerization is carried out by a batch method, the above catalyst components are used in the concentrations described below.
When the olefin polymerization is carried out using the olefin polymerization catalyst as described above, the component (A) is usually 10 ⁻⁹ to 10 ⁻¹ mol, preferably 10 ⁻⁸ to 10 ⁻² mol per liter of reaction volume. It is used in such an amount that it becomes a mole.

Component (b-1) has a molar ratio [(b-1) / M] of component (b-1) to all transition metal atoms (M) in component (A) of usually 0.01 to 5, 000, preferably 0.05 to 2,000. In the component (b-2), the molar ratio [(b-2) / M] of the ionic compound in the component (b-2) and the total transition metal (M) in the component (A) is usually 0. 0.01 to 5,000, preferably 1 to 2,000. The component (b-3) has a molar ratio [(b-3) / M] of the component (b-3) and the transition metal atom (M) in the component (A) of usually 1-1.
The amount used is 0000, preferably 1 to 5000.

In the polymerization reaction, the temperature is usually 10 g of wax set on a filter, -20 to + 200 ° C., preferably 50 to 180 ° C., more preferably 70 to 180 ° C., and the pressure usually exceeds 0. It is performed under conditions of 8 MPa (80 kgf / cm ² , gauge pressure) or less, preferably more than 0 and 4.9 MPa (50 kgf / cm ² , gauge pressure) or less.

  In the polymerization, ethylene and the α-olefin used as needed are supplied to the polymerization system in such a proportion that the polyethylene wax having the specific composition described above can be obtained. In the polymerization, a molecular weight regulator such as hydrogen can be added.

When polymerized in this manner, the produced polymer is usually obtained as a polymerization solution containing the polymer, so that polyethylene wax can be obtained by treatment by a conventional method.
In the present invention, it is particularly preferable to use a catalyst containing the metallocene compound shown in <Example 1 of metallocene compound>.

When such a catalyst is used, a polyethylene wax having the above-described characteristics can be easily obtained.
The shape of the polyethylene wax of the present invention is not particularly limited, but is usually pellet-like or tablet-like particles.

[Other ingredients]
In the present invention, in addition to the polyethylene and the polyethylene wax, additives such as antioxidants, UV absorbers, light stabilizers, metal soaps, fillers, flame retardants, and the like are further used as necessary. May be used in addition to. Further, by adding a foaming agent, foam molding can be performed. In particular, when a low-temperature foaming agent is used, low-temperature foam molding is possible.

Examples of the stabilizer include antioxidants such as hindered phenol compounds, phosphite compounds, and thioether compounds;
UV absorbers such as benzotriazole compounds and benzophenone compounds;
Examples thereof include light stabilizers such as hindered amine compounds.

Examples of the metal soap include stearates such as magnesium stearate, calcium stearate, barium stearate, and zinc stearate.
Examples of the filler include calcium carbonate, titanium oxide, barium sulfate, talc, clay, and carbon black.

Examples of the flame retardant include halogen compounds such as halogenated diphenyl ether and halogenated polycarbonate such as degabromo diphenyl ether and octabromo diphenyl ether; antimony trioxide, antimony tetraoxide, antimony pentoxide, sodium pyroantimonate, aluminum hydroxide, etc. Inorganic compounds; phosphorus compounds and the like.

Moreover, a compound such as tetrafluoroethylene can be added as a flame retardant aid for preventing drip.
Examples of the antibacterial and antifungal agents include organic compounds such as imidazole compounds, thiazole compounds, nitrile compounds, haloalkyl compounds, and pyridine compounds;
Examples include inorganic substances such as silver, silver compounds, zinc compounds, copper compounds, and titanium compounds, and inorganic compounds.

Among these compounds, thermally stable silver and silver-based compounds are preferable.
As said silver type compound, silver salts, such as a silver complex, a fatty acid, and phosphoric acid, can be mentioned.
When silver and silver-based compounds are used as antibacterial and antifungal agents, these substances can be used in porous structures such as zeolite, silica gel, zirconium phosphate, calcium phosphate, hydrotalcite, hydroxyapatite, and calcium silicate. In some cases, it is used while being supported.
Examples of other additives include colorants, plasticizers, anti-aging agents, colorants, plasticizers, and oils.

[Raw material composition ratio]
The composition ratio of polyethylene and polyethylene wax used as a raw material of the present invention is not particularly limited as long as the physical properties of the obtained molded article are not impaired, but usually 0.01 to 10 parts by weight with respect to 100 parts by weight of polyethylene. The range is preferably 0.1 to 5 parts by weight, more preferably 0.5 to 3 parts by weight.

  When polyethylene and polyethylene wax are used at a composition ratio in the above range, the effect of improving fluidity is greater than when polyethylene wax is not added, and even when injection molding is performed at a low molding temperature, the same degree of machinery is used. An injection-molded article having specific physical properties can be obtained, and deterioration of mechanical properties due to the addition of wax can be suppressed. Further, when molding is performed at a low molding temperature, the cooling time is shortened and the molding cycle is improved. Furthermore, by lowering the molding temperature, it is possible not only to suppress the thermal deterioration of the resin and the resin strength, but also to suppress the scorching and black spots of the resin.

〔injection molding〕
In the method for producing a molded article of the present invention, the raw material is injection molded.
There is no restriction | limiting in particular about injection molding, A conventionally well-known method is applicable. Usually, raw materials such as polyethylene and polyethylene wax added from a hopper are melt-kneaded in a heating cylinder, and the melt-kneaded material is filled into a mold by an injection device, and the resin composition in the mold is cooled and solidified. After that, the molded product is taken out from the mold.

  Polyethylene and polyethylene wax may be mixed in advance (preliminary mixing) before being supplied to the injection device, or may be mixed by supplying polyethylene wax to the resin supplied to the injection device (for example, side feed). . In any of the above cases, a mixture of polyethylene and polyethylene wax is formed during injection. The premixing method is not particularly limited, and may be melt mixing or dry blending. Examples of the apparatus used for dry blending include a high-speed mixer such as a Henschel mixer, and a tumbler. Examples of the apparatus used for melt kneading include a plast mill, a kneader, a roll mixer, a Banbury mixer, a Brabender, a single screw extruder, a twin screw extruder, and the like.

According to the present invention, the injection molding temperature (resin temperature) is 5 ° C. or more, preferably 10 ° C., with respect to the temperature in the range of 140 to 300 ° C. when no polyethylene wax is added. As described above, it can be set at a temperature lower by 15 ° C. or more. Here, the “injection molding temperature in the case of not containing polyethylene wax” is an optimum injection molding temperature that is appropriately determined depending on the polyethylene to be used in consideration of the molding speed and the physical properties of the molded article to be obtained. For example, in the case of crystalline polyethylene, the optimum injection molding temperature Tpc ₀ can be determined from the crystal melting temperature T _{m according} to the following formula.

Tpc ₀ = 3/4 × T _m +100
On the other hand, the “injection molding temperature when polyethylene wax is included” is an injection molding temperature at which the screw torque is the same as the screw torque of the extruder at the injection molding temperature when polyethylene wax is not included. Here, the above “same” includes an error of about 5%.

  Thus, if the molding temperature can be lowered, scorching at the time of injection molding can be prevented. Moreover, even if polyethylene wax is added to the obtained injection-molded product, no deterioration in physical properties is observed. In addition, since the molding temperature can be lowered, the mold cooling time can be shortened. As a result, the molding cycle can be increased, and the productivity can be improved with existing equipment. Furthermore, since it can be injection-molded at a low temperature, foaming at a low temperature is also possible.

  In addition, conventionally well-known conditions can be employ | adopted for the injection molding conditions except injection molding temperature. Specifically, the injection pressure is usually 30 to 100 MPa, preferably 30 to 50 MPa, and the mold temperature is usually 20 to 40 ° C., preferably 25 to 35 ° C.

[Example]
EXAMPLES Hereinafter, although this invention is demonstrated further more concretely based on an Example, this invention is not limited to these Examples.

In the following examples, the physical properties of polyethylene and polyethylene wax were measured as follows.
(Number average molecular weight (Mn))
The number average molecular weight (Mn) is obtained from GPC measurement. The measurement was performed under the following conditions. Moreover, the number average molecular weight (Mn) calculated | required the molecular weight based on the following conversion method, creating a calibration curve using the commercially available monodisperse standard polystyrene.
Apparatus: Gel permeation chromatograph Alliance GPC2000 (manufactured by Waters)
Solvent: o-dichlorobenzene column: TSKgel column (manufactured by Tosoh Corporation) x 4
Flow rate: 1.0 ml / min Sample: 0.15 mg / mL o-dichlorobenzene solution temperature: 140 ° C.
Molecular weight conversion: PE conversion / General calibration method

In addition, the coefficient of the Mark-Houwink viscosity formula shown below was used for calculation of general-purpose calibration.
Coefficient of polystyrene (PS): KPS = 1.38 × 10 ⁻⁴ , aPS = 0.70
Coefficient of polyethylene (PE): KPE = 0.06 × 10 ⁻⁴ , aPE = 0.70
(A value, B value)
From the GPC measurement results described above, the proportion of the component having a molecular weight of 1,000 or less is determined by weight%,
A value was used. Further, from the measurement result of GPC, the ratio of the component having a molecular weight of 20,000 or more was determined by weight%, and the B value was obtained.

(Melt viscosity)
Measurements were made at 140 ° C. using a Brookfield viscometer.
(density)
It was measured according to the density gradient method of JIS K7112.

(Melting point)
It measured using the differential scanning calorimeter (DSC) [DSC-20 (made by Seiko Denshi Kogyo Co., Ltd.)]. First, the measurement sample was once heated to 200 ° C. and held for 5 minutes, and then immediately cooled to room temperature. About 10 mg of this sample was subjected to DSC measurement in the temperature range from −20 ° C. to 200 ° C. under the temperature rising rate of 10 ° C./min. The endothermic peak value of the curve obtained from the measurement results was taken as the melting point.

(Crystal melting temperature)
The crystal melting temperature (T _m , ° C.) was measured under the condition of a temperature drop rate of 2 ° C./min according to ASTM D 3417-75.

[Comparative Example 1]
Low-density polyethylene (trade name: Mirason 403P, manufactured by Prime Polymer Co., Ltd., crystal melting temperature: 108 ° C., density: 921 kg / m ³ , MI: 7.0 g / 10 min) is injection-molded under the following conditions to give a molded product It produced and evaluated various physical properties. The results are shown in Table 1.

[Injection molding conditions]
Injection molding machine: 55ton injection molding machine (IS55EPNi1.5B) manufactured by Toshiba Machine Co., Ltd.
Molding temperature (cylinder setting temperature): 180 ° C
Injection pressure (primary): 35 MPa
Injection speed: 80mm / sec
Injection time: 15 seconds Mold temperature: 30 ° C
Mold cooling time: 20 seconds

〔Evaluation of the physical properties〕
(Releasability)
A flat plate (110 mm in length x 120 mm in width x 2 mm in thickness) is injection-molded under the above conditions with the above-mentioned injection molding machine, and after cooling the mold for a predetermined time, the molded product in the mold is pushed out with an ejection pin, and the mold release at this time Sex was judged according to the following criteria.
○: The molded product is released without resistance and does not deform.
X: The molded product is deformed due to large release resistance due to sticking to the mold.

(Flow mark)
A flat plate (length 110 mm × width 120 mm × thickness 2 mm) was injection molded under the above conditions using the injection molding machine, and a flow mark was observed.
○: No flow mark ×: With flow mark (Tensile fracture stress, tensile yield stress)
A test piece (1BA type test piece) was prepared under the above-described conditions using the injection molding machine, and the tensile fracture stress and the tensile yield stress were measured at a tensile speed of 50 mm / min according to JIS K7161.

(Bending elastic modulus, bending strength)
Test pieces were prepared under the above conditions using the injection molding machine, and the flexural modulus and flexural strength were measured at a fulcrum distance of 48 mm and a test speed of 5.0 mm / min in accordance with JIS K7171.

(Heat-resistant)
A test piece was prepared under the above conditions using the above injection molding machine, and the Vicat softening point was measured by the A50 method in accordance with JIS K7206.

(Impact resistance)
A test piece (type 1A test piece with a notch) was prepared under the above conditions using the injection molding machine, and an Izod impact value was measured in accordance with JIS K7110.

[Comparative Example 2]
Except that the molding temperature was changed to 160 ° C., injection molding of low-density polyethylene (Mirason 403P) was attempted in the same manner as in Comparative Example 1, but a short shot was obtained, and a good molded body could not be obtained.

[Comparative Example 3]
Ziegler-based polyethylene wax (trade name: High Wax (registered trademark) 420P, manufactured by Mitsui Chemicals, Inc., ethylene content 97 mol%), density: 100 parts by weight of low-density polyethylene (Mirason 403P) 2 parts by weight of 930 kg / m ³ , average molecular weight (Mn): 2000, melt viscosity (140 ° C.): 700 mPa · s, A value: 8.3% by weight, B value: 6.2% by weight Mix well in a mixer to make a mixture of low density polyethylene and polyethylene wax.

  This mixture was used in place of low density polyethylene (Mirason 403P), the molding temperature was changed to 160 ° C., and the mold cooling time was changed to 15 seconds. Physical properties were evaluated. The results are shown in Table 1.

[Example 1]
Metallocene polyethylene wax prepared using a metallocene catalyst instead of Ziegler polyethylene wax (High Wax (registered trademark) 420P) (trade name: Excellex (registered trademark) 48070BT, manufactured by Mitsui Chemicals, Inc., ethylene content 92 mol %, Density: 902 kg / m ³ , average molecular weight (Mn): 3400, melt viscosity (140 ° C.): 13
50 mPa · s, A value: 4.7 wt%, B value: 8.7 wt%) were used in the same manner as in Comparative Example 3 except that 2 parts by weight were used, and various physical properties were evaluated. The results are shown in Table 1.

  A comparison between Example 1 and Comparative Examples 1 and 2 shows that when polyethylene wax is added to low density polyethylene, the physical properties of the molded product are not lowered even when the molding temperature is lower by 20 ° C. or more than when no molding temperature is added. It can be seen that injection molding is possible. Further, it can be seen that the mold cooling time can be shortened. Further, when Example 1 and Comparative Example 3 are compared, the low-density polyethylene has a relationship between the melt viscosity and the B value satisfying the relationship of the formula (I), and the melt viscosity and the A value satisfying the relationship of the formula (II). By adding polyethylene wax obtained using a catalyst that satisfies the requirements, it is possible to produce an injection-molded product with excellent mechanical properties compared to the case of using a conventional wax, and the mold release property is also good. I know that there is.

Claims (2)

The density measured according to the density gradient tube method of JIS K7112 is in the range of 900 (kg / m ³ ) or more and less than 940 (kg / m ³ ), MI measured under conditions of 190 ° C. and test load 21.18 N according to JIS K7210 Has a density measured in accordance with the density gradient tube method of JIS K7112 in the range of 890 to 980 (kg / m ³ ), and gel permeation chromatography (GPC) Molded by injection molding a mixture containing a polyethylene wax having a polyethylene-equivalent number average molecular weight (Mn) in the range of 500 to 4,000 and satisfying the relationship represented by the following formula (I) A method of manufacturing a body.
B ≦ 0.0075 × K (I)
(In the above formula (I), B is a content ratio (% by weight) of a component having a polyethylene conversion molecular weight of 20,000 or more in the polyethylene wax when measured by gel permeation chromatography, and K Is the melt viscosity (mPa · s) of the polyethylene wax at 140 ° C.) The method for producing a molded article by injection molding according to claim 1, wherein the polyethylene wax further satisfies a relationship represented by the following formula (II).
A ≦ 230 × K ^(-0.537) (II)
(In the above formula (II), A is a content ratio (% by weight) of a component in which the molecular weight in terms of polyethylene in the polyethylene wax is 1,000 or less when measured by gel permeation chromatography, and K Is the melt viscosity (mPa · s) of the polyethylene wax at 140 ° C.)