JPH11198920A - Clean ethylene polymer bottle with narrow molecular weight distribution - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ethylene polymer bottle that is excellent in moldability and cleanliness. SOLUTION: 0.01-0.3 pts.wt. of organic peroxide is added to 100 pts.wt. of material ethylene polymer having 0.8-5 g/10 min. of melt index MI2.16 (A), 3-5 molecular weight distribution by gel permeation chromatography (B) and 0.95 g/cm<3> or higher of density (C), and modified ethylene polymer, obtained after melting and mixing, in 0.1-0.5 g/10 min. of melt index MI2.16 (D), 4-7 molecular weight distribution by gel permeation chromatography (E), 0.95 g/cm<3> or more of density (F) and 50 or more in the radio of MI2.16 to MI2.16 , MI2.16 /MI2.16 , is formed into a molded article by blow molding.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an ethylene polymer bottle. More specifically, the present invention relates to a clean ethylene polymer bottle obtained by blow molding an ethylene polymer modified using a specific raw material ethylene polymer. More specifically, using a raw material ethylene polymer having a specific melt viscosity, molecular weight distribution, and density, partially cross-linking the raw material ethylene polymer with an organic peroxide, and molding the obtained specific modified ethylene polymer The present invention relates to a clean ethylene polymer bottle obtained by the above method.

[0002]

2. Description of the Related Art In recent years, medical containers and high-purity reagent containers have been required to have higher cleanliness, but there is no ethylene polymer satisfying cleanliness and moldability. For example, JP-A-9-77921 discloses a bimodal composition comprising a specific high molecular component and a low molecular component. Although this composition is somewhat satisfactory in formability, it is not satisfactory in terms of cleanliness. In this composition, the low molecular component has a moldability improving effect,
On the other hand, it greatly reduces the cleanliness of the container.

[0003] On the other hand, when a normal monomodal ethylene polymer is used, normal blow molding is difficult. Therefore, as a method for improving the melt moldability of a monomodal ethylene polymer, there is a method of inserting a long-chain branch into a molecule.
As a method for inserting the long-chain branch, a method of polymerizing ethylene in the presence of a special catalyst, or a small amount of a cross-linking reaction of a raw material ethylene polymer after polymerization by an appropriate method to form a long-chain branch in the molecule. There is a way to insert. An attempt to insert a long-chain branch by this cross-linking technique is disclosed in JP-A-52-82964.
Japanese Patent Application Laid-Open No. H07-271403 discloses an attempt to improve moldability by adding a radical generator to polyethylene, and a technique of modifying linear low-density polyethylene with a radical generator. .

However, the polyethylene used in the above technique is a conventional polyethylene polymerized with a Ziegler catalyst. This conventional polyethylene has a wide molecular weight distribution. Since the conventional polyethylene contains a large amount of low molecular weight components that degrade the cleanliness, which is the object of the present invention, even if the polyethylene is modified, sufficient cleanliness cannot be obtained.

In recent years, an attempt has been made to produce an ethylene polymer having improved mechanical properties by using a catalyst prepared from a metallocene compound and an aluminoxane.
Nos. 8-19309, 60-35006, 60-35007, 61-130314, 61-221208, and 62-12170.
Nos. 9 and 62-121711. However, even if the ethylene polymer obtained by these production methods is crosslinked in a small amount, sufficient moldability cannot be obtained.

[0006]

DISCLOSURE OF THE INVENTION An object of the present invention has been made in view of the above-mentioned problems, and has been made by using a modified ethylene polymer having excellent moldability and excellent in cleanliness. It is to provide a polymer bottle.

[0007]

Means for Solving the Problems As a result of intensive studies, the present inventors have found an ethylene polymer bottle using a modified ethylene polymer having excellent moldability, processability and cleanness.
That is, the present invention relates to (A) a melt index MI _2.16 at 190 ° C. under a load of 2.16 kg of 0.8 to 5 g / 10 min. (B) a molecular weight distribution measured by gel permeation chromatography of 3 to 5, C) 0.01 to 0.3 parts by weight of an organic peroxide was added to 100 parts by weight of a raw material ethylene polymer having a density of 0.95 g / cm ³ or more, and melt-mixed. Melt index MI _{2.16 under} 0.16 kg load is 0.1 to 0.5 g / 10 min, (E) molecular weight distribution measured by gel permeation chromatography is 4 to 7, (F) density is 0.95 g / cm ³ or more (G) Ratio of melt index MI _21.6 to MI _{2.16 at 21.6} kg load at 190 ° C. MI _21.6 / MI
_2.16 is a clean ethylene polymer bottle obtained by blow-molding a modified ethylene polymer having 50 or more.

Hereinafter, the present invention will be described in detail. The starting ethylene polymer used in the present invention is an ethylene homopolymer or a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms, preferably 4 to 20 carbon atoms. Examples of the α-olefin having 3 to 20 carbon atoms include propylene, butene-1, pentene-1,3-methylbutene-1, hexene-1,4-methylpentene-1, octene-1, decene-1, tetradecene-1, hexadecene-1, octadecene-1, eicocene-1 and the like. Can be used. Further, vinyl compounds such as vinylcyclohexane or styrene and derivatives thereof can also be used. If necessary, a ternary random polymer containing a small amount of a non-conjugated polyene such as 1,5-hexadiene and 1,7-octadiene may be used. The amount of the α-olefin to be inserted is such that the density (C) of the ethylene polymer is 0.95 g / cm ³ or more, preferably 0.96 g / cm ³ or more, and more preferably 0.96 g / cm ³ or more.
5 g / cm ³ . The density here is measured by a density gradient tube after heat-treating the strand obtained at the time of the melt index measurement at 120 ° C. for 1 hour and further cooling it at room temperature for 1 hour. If the density is less than 0.95 g / cm ³ , the crystallinity will be low and the cleanness will be poor.

The raw material ethylene polymer (A) has a melt index MI _2.16 at 190 ° C. under a load of 2.16 kg.
Is 0.8 to 5 g / 10 min, preferably 1.5 to 4 g
/ 10 minutes. Even if the raw material ethylene polymer of less than 0.8 g / 10 min is modified with an organic peroxide and the MI _2.16 of the modified ethylene polymer is adjusted from 0.1 to 0.5 g / 10 min, it is blown. Insufficient swell for molding. In addition, using a raw ethylene polymer exceeding 5 g / 10 min and modifying it with an organic peroxide, the modified ethylene polymer MI _2.16
If it is attempted to adjust the concentration to 0.1 to 0.5 g / 10 minutes, it is necessary to add a large amount of organic peroxide. As a result, a large amount of gel is generated in the modified ethylene polymer, and the appearance of the bottle becomes poor.

The molecular weight distribution (B) of the starting ethylene polymer used in the present invention is 3 to 5, preferably 3.5 to 4.5 as measured by gel permeation chromatography. If the molecular weight distribution is less than 3,
Blow molding cannot be performed due to insufficient swell of the modified ethylene polymer. If the molecular weight distribution exceeds 5, low molecular weight components are easily extracted, which causes a problem that cleanliness is reduced.

The measuring apparatus used for the gel permeation chromatography was 150-C manufactured by Waters.
ALC / GPC, column of Shodex A
T-807S and TSK-gelGMH manufactured by Tosoh Corporation
Measurement is performed at 140 ° C. using -H6 in series and trichlorobenzene as a solvent. Next, a method for producing a raw ethylene polymer having the characteristics (A) to (C) will be described.

The ethylene polymer used in the present invention comprises (A)
Carrier material (a) organic aluminum compound (c) borate compound having active hydrogen (d) using a supported catalyst prepared from a titanium compound η-bonded with a cyclopentadienyl or substituted cyclopentadienyl group, in a slurry state Ethylene alone or ethylene and α with 3 to 20 carbon atoms
-Obtained by copolymerization with olefin.

The carrier substance (A) may be either an organic carrier or an inorganic carrier. The organic carrier is preferably an α-olefin polymer having 2 to 10 carbon atoms, for example, (1) polyethylene, polypropylene, polybutene-1, ethylene-propylene copolymer, ethylenebutene-1 copolymer, ethylene-hexene-1 Copolymer, propylene butene-1 copolymer, propylene divinyl benzene copolymer, (2) aromatic unsaturated hydrocarbon polymer such as polystyrene, styrene divinyl benzene copolymer, and (3) polar group Containing polymers, such as polyacrylates, polymethacrylates,
Polyacrylonitrile, polyvinyl chloride, polyamide,
Polycarbonate and the like. As the inorganic carrier, for example, SiO ₂ , Al ₂ O ₃ , MgO, TiO ₂ , B
₂ O ₃ , CaO, ZnO, BaO, ThO, SiO ₂ -M
_{gO, SiO 2 -Al 2 O 3} , SiO 2 over MgO, SiO ₂
Over V ₂ O _5, etc., (4) an inorganic halogen compounds e.g. MgC
(5) inorganic carbonates such as l ₂ , AlCl ₃ , MnCl ₂ ,
Sulfates, nitrates such as Na ₂ CO ₃ , K ₂ CO ₃ , Ca
CO ₃ , MgCO ₃ , Al ₂ (SO ₄ ) ₃ , BaSO ₄ , KN
(6) oxides such as O ₃ , Mg (NO ₃ ) ₂ etc.
(OH) ₂ , Al (OH) ₃ , Ca (OH) _{2 and the} like. The most preferred support material is silica. The particle size of the carrier is arbitrary, but is generally preferably 1 to 3000 μm, more preferably 5 to 2000 μm, and particularly preferably 10 to 1000 μm.

The carrier material is treated with an organic aluminum compound (a). Examples of preferred organic aluminum compounds include trimethylaluminum, triethylaluminum, triisobutylaluminum, trihexylaluminum, trioctylaluminum, tridecylaluminum, diethylaluminum monochloride, diisobutylaluminum monochloride, ethylaluminum sesquichloride, ethylaluminum dichloride, Alkyl aluminum hydrides such as diethylaluminum hydride, diisobutylaluminum hydride, etc., aluminum alkoxides such as diethylaluminum ethoxide, dimethylaluminum trimethylsiloxide, dimethylaluminum phenoxide, etc., methylalumoxane, ethylaluminoxane, isobutyl Rumikisan,
Alumoxanes such as methylisobutylalumoxane and the like can be mentioned. Of these, trialkylaluminum, aluminum alkoxide and the like are preferable. Most preferred are trimethylaluminum, triethylaluminum and triisobutylaluminum.

Further, as a supported catalyst used in the process for producing ethylene homopolymer or copolymer used in the present invention, a borate compound having active hydrogen represented by the following general formula (1) is used. This borate compound is an activator that reacts with a titanium compound (d) that is η-bonded to a cyclopentadienyl or substituted cyclopentadienyl group to convert (d) into a cation. The group (TH) having active hydrogen forms a chemical bond or a physical bond with the carrier when the borate compound is carried on the carrier material.

[B ^- Qn (Gq (TH) r) z] A ⁺ (1) where B represents boron. G represents a multi-bonded hydrocarbon radical. Preferred examples of the multi-bonded hydrocarbon include alkylene, arylene, ethylene, and alkylene radicals each having 1 to 20 carbon atoms. Preferred examples of G include phenylene, bisphenylene, and naphthalene.
Examples include methylene, ethylene, 1,3-propylene, 1,4-butadiene and p-phenylenemethylene. The multibond radical G has an r + 1 bond, that is, one bond bonds to the borate anion, and the other bond of G bonds to the (TH) group.

T represents O, S, NR, or PR;
Represents a hydrocarbanyl radical, a trihydroicarbanylsilyl radical, a trihydrocarbanylgermanium radical, or a hydride. q is 1 or more, and preferably 1. -O for TH group
H, -SH, -NRH, or -PRH where R is C1
To C18, preferably C1 to C10 hydrocarbyl radicals or hydrogen. Preferred R groups are alkyl, cycloalkyl, allyl, allylalkyl or alkylallyl having 1 to 18 carbon atoms.
-OH, -SH, -NRH or -PRH is for example-
C (O) -OH, -C (S) -SH-C (O) -NR
H and C (O) -PRH may be used. The most preferred group having active hydrogen is an -OH group.

Q is hydride, dihydrocarbylamide, preferably dialkylamide, halide, hydrocarbyloxide, alkoxide, allyloxide,
Hydrocarbyl, substituted hydrocarbyl radicals and the like. Here, n + z is 4. Of the above-mentioned general formula [B ^over
Qn (Gq (TH) r) z], for example, triphenyl (hydroxyphenyl) borate, diphenyldi (hydroxyphenyl) borate, triphenyl (2,4 dihydroxyphenyl) borate tri (totril) (hydroxyphenyl) Borate, tris (pentafluorophenyl) (hydroxyphenyl) borate, tris (2,4-dimethylphenyl) (hydroxyphenyl) borate, tris (3,5-dimethylphenyl) (hydroxyphenyl) borate, tris (3,5- D-trifluoromethylphenyl) (hydroxyphenyl) borate, tris (pentafluorophenyl) (2-hydroxyethyl) borate, tris (pentafluorophenyl) (4-hydroxybutyl) borate, tris ( Pentafluorophenyl)
(4-hydroxy-cyclohexyl) borate, tris (pentafluorophenyl) (4- (4 ^, -hydroxyphenyl) phenyl) borate, tris (pentafluorophenyl) (6-hydroxy-2naphthyl) borate, most preferably tris (Pentafluorophenyl) (4-hydroxyphenyl) borate. Further, the --OH group of the borate compound is replaced with --NHR
(Where R is methyl, ethyl, t-butyl) is also preferable.

Examples of the counter cation of the borate compound include a carbonium cation, a tropylluium cation, an ammonium cation, an oxonium cation, a sulfonium cation, and a phosphonium cation. Metal cations and organic metal cations whose self-confidence is easily reduced can also be mentioned. Specific examples of these cations include triphenylcarbonium ion, diphenylcarbonium ion, cycloheptatrinium, indenium, triethylammonium, tripropylammonium, tributylammonium,
Dimethyl ammonium, dipropyl ammonium,
Dicyclohexylammonium, trioctylammonium, N, N-dimethylammonium, diethylammonium, 2,4,6-pentamethylammonium, N, N-dimethylbenzylammonium, di-ammonium
(I-propyl) ammonium, dicyclohexylammonium, triphenylphosphonium, triphosphonium, tridimethylphenylphosphonium, tri (methylphenyl) phosphonium, triphenylphosphonium ion, triphenyloxonium ion, triethyloxonium ion, Pyrinium,
Examples include silver ions, gold ions, platinum ions, copper ions, palladium ions, mercury ions, and ferrocenium ions. Of these, ammonium ions are particularly preferred.

A titanium compound (d) which is η-bonded to a cyclopentadienyl or substituted cyclopentadienyl group represented by the following general formula (2) is used.

[0021]

Embedded image

Here, Ti is a titanium atom in an oxidation state of +2, +3, +4, Cp is a cyclopentadienyl or substituted cyclopentadienyl group which is η-bonded to titanium, X1 is an anionic ligand, X2 is a neutral conjugated diene compound. n + m is 1 or 2, Y is -O-, -S-, -NR- or -PR-, and Z is
SiR ₂ , CR ₂ , SiR ₂ -SiR ₂ , CR ₂ CR ₂ , CR =
CR, CR ₂ SiR ₂ , GeR ₂ , BR ₂ , where R is hydrogen, hydrocarbyl, silyl, germum, cyano, halo or a combination thereof and 2
Selected from those combinations having up to zero non-hydrogen atoms.

The substituted cyclopentadienyl group includes 1
At least one C1 to C20 hydrocarbyl, a C1 to C20 halohydrocarbyl, a cyclopentadienyl, an indenyl, a tetrahydroindenyl substituted with a halogen or a C1 to C20 hydrocarbyl-substituted Group 14 metalloid group , Fluorenyl or octafluorenyl, preferably C1-C6
Is a cyclopentadienyl group substituted with an alkyl group.

As X1 and X2, for example, in the above general formula, when n is 2, m is 0 and the oxidation number of titanium is +4, X1 is selected from methyl and benzyl, and n is 1 and m
Is 0 and the oxidation number of titanium is +3, X1 is 2- (N,
If N-dimethyl) aminobenzyl and the oxidation number of titanium are +4, X1 is 2-butene-1,4-diyl, and if n is 0, m is 1 and the oxidation number of titanium is +2, X2 is 1,4. Diphenyl-1,3-butadiene or 1,3-pentadiene.

In the present invention, a molecular weight distribution of 3 to 5 of the raw material ethylene polymer suitable for the present invention can be obtained by slurry-polymerizing ethylene using the component (c) and the component (d). Such a wide molecular weight distribution cannot be obtained by conventional polymerization using a metallocene compound.
The catalyst used in the present invention can be obtained by supporting the component (a), the component (c), and the component (d) on the component (a), and the method of supporting the component (d) from the component (a) is optional. However, generally, a method of dissolving the components (a), (c) and (d) in an inert solvent in which each can be dissolved, mixing with the component (a), and distilling off the solvent. In addition, after dissolving the components (a), (c) and (d) in an inert solvent, the solids are concentrated within a range not causing precipitation of solids, and the whole amount of the next concentrated liquid can be retained in the particles. A method of adding an amount of the component (a), a method of first supporting the component (a) and the component (c) on the component (a), and then supporting the component (d), and a method of supporting the component (a) on the component (a) (D) a method of sequentially supporting component (c), component (a), component (a), component (c) and The co-milling the fine component (d),
Examples of the method of supporting are exemplified. Since the component (c) and the component (d) of the present invention are generally solid, and the component (a) has spontaneous combustion, these components are diluted with an inert solvent during loading. May be used.

The inert solvent used for this purpose includes:
For example, aliphatic hydrocarbons such as propane, butane, pentane, hexane, heptane, octane, decane, dodecane and kerosene; alicyclic hydrocarbons such as cyclopentane, cyclohexane and methylcyclopentane; aromatics such as benzene, toluene and xylene Hydrocarbon; and halogenated hydrocarbons such as ethyl chloride, chlorobenzene, and dichloromethane, and mixtures thereof. Such an inert hydrocarbon solvent, using a desiccant, an adsorbent, and the like,
It is desirable that impurities such as water, oxygen, and sulfur be removed before use.

For each gram of component (a), (a) is Al
1 × 10 in atom conversion^-5From 1 × 10 ^{ー 1}Mole is preferred,
More preferably, 1 × 10^{ー 4}5 × 10 from mole^{ー 2}Mole,
(C) is 1 × 10^-71 x 10 from mole^{ー 3}Mol is preferred
And more preferably 5 × 10 ^-75 × 10 from mole^{ー 4}Mo
Le, (d) is 1 × 10^-71 x 10 from mole^{ー 3}Prefer mol
And more preferably 5 × 10^-75 × 10 from mole^-Four
Range of moles. Each amount used and loading method are
Cost, powder characteristics, scale in the reactor, etc.
Is determined. The obtained supported catalyst is supported on a carrier.
Organic aluminum compounds, borate compounds,
Inert hydrocarbon solvent to remove tan compounds
Decantation or filtration using a medium
It can also be washed.

The above series of operations such as dissolving, contacting, washing, etc.
It is recommended to perform at a temperature in the range of −30 ° C. to 150 ° C. selected for each unit operation. A more preferable range of such a temperature is 0 ° C or higher and 100 ° C or lower. A series of operations for obtaining the supported catalyst is preferably performed in a dry inert atmosphere. The supported catalyst used in the present invention can be stored in a slurry state dispersed in an inert hydrocarbon solvent, or can be dried and stored in a solid state.

In the polymerization of the starting ethylene polymer, the polymerization pressure is generally preferably 1 to 100 atm, more preferably 3 to 30 atm, and the polymerization temperature is preferably 20 to 115 ° C. Preferably 50 ° C
~ 90 ° C is preferred. However, the upper limit of the temperature is a temperature at which the raw material ethylene polymer to be produced can substantially maintain a slurry state. When the temperature exceeds this value, the molecular weight distribution of the raw material ethylene polymer becomes less than 3.

As the solvent used in the slurry method, the inert hydrocarbon solvent described above in the present invention is preferable, and in particular, isobutane, isopentane, heptane, hexane,
Octane and the like are preferred. The comonomer that can be used in the present invention is an α-olefin represented by the following general formula (3).

H ₂ C ＝ CHR ₂ (3) (wherein R ₂ is an alkyl group having 1 to 18 carbon atoms or an aryl group having 6 to 20 carbon atoms;
It is branched or cyclic. Such comonomers include, for example, propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene,
-Tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, vinylcyclohexane, and styrene, and a cyclic olefin having 3 to 20 carbon atoms is, for example, cyclopentene, cycloheptene,
From norbornene, 5-methyl-2-norbornene, tetracyclododecene, and 2-methyl-1.4,5.8-dimethano-1,2,3,4,4a, 5,8,8a-octahydronaphthalene Selected from the group consisting of 4 to 2 carbon atoms
0 linear, branched or cyclic dienes are, for example, 1,
It is selected from the group consisting of 3-butadiene, 1,4-pentadiene, 1,5-hexadiene, 1,4-hexadiene, and cyclohexadiene.

In the present invention, propylene, 1-
Butene, 1-pentene, 1-hexene, 4-methyl-1
-Pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene and the like are preferred. The supported catalyst used in the present invention is capable of polymerizing ethylene or ethylene and α-olefin by itself, but is used in the presence of an organic aluminum compound as an additional component to prevent poisoning of the solvent and the reaction system. It is also possible. Examples of preferred organic aluminum compounds include trimethylaluminum, triethylaluminum, triisobutylaluminum, trihexylaluminum, trioctylaluminum, tridecylaluminum, diethylaluminum monochloride, diisobutylaluminum monochloride, ethylaluminum sesquichloride, ethylaluminum dichloride, Alkyl aluminum hydrides such as diethylaluminum hydride, diisobutylaluminum hydride, etc., aluminum alkoxides such as diethylaluminum ethoxide, dimethylaluminum trimethylsiloxide, dimethylaluminum phenoxide, etc., methylalumoxane, ethylaluminoxane, isobutyl Rumikisan, like alumoxane, such as methyl isobutyl alumoxane. Of these, trialkylaluminum, aluminum alkoxide and the like are preferable. Most preferred are trimethylaluminum, triethylaluminum and triisobutylaluminum.

The organic peroxide is decomposed into radicals in the melt-mixing step, and finely crosslinks the starting ethylene polymer. The organic peroxide is based on 100 parts by weight of the raw material ethylene polymer.
It is preferably 0.01 to 0.3 part by weight, more preferably 0.03 to 0.2 part by weight, particularly preferably 0.5 to 0.1 part by weight. If the amount is less than 0.01 part by weight, crosslinking is insufficient, and if it exceeds 0.3 part by weight, a large amount of ultrahigh molecular weight gel is generated in the bottle. As organic peroxides,

[0034]

Embedded image -Containing ketone peroxide compounds

[0035]

Embedded image Peroxyketal compound having a group R ₃ —O—O—H (6) Hydroperoxide compound having a group R ₃ —O—O—R ₃ (7) Dialkyl peroxide compound having a group

[0036]

Embedded image Diacyl Peroxide Compound Having a Group

[0037]

Embedded image Or

[0038]

Embedded image Peroxyester compound having a group

[0039]

Embedded image

And a peroxydicarbonate compound having a group (wherein R _3, R _{4 and} R ₅ represent an alkyl group, a substituted alkyl group, an alkylene group or a substituted alkylene group). Organic peroxides include dialkyl peroxide compounds such as dicumyl peroxide, 2.5
-Dimethyl-2,5-bis (t-butylperoxy) hexane and 2,5-dimethyl-2,5-bis (t-butylperoxy) hexyne-3 are preferred.

The temperature of the organic peroxide is preferably 180 ° C. or higher, more preferably 200 ° C. or higher, particularly preferably 230 ° C. or higher, as the temperature of melting and mixing with the raw material ethylene polymer. When this temperature is low, the decomposition of the organic peroxide is insufficient, and a sufficient reforming effect cannot be obtained. As the melt mixing of the raw material ethylene polymer and the organic peroxide, a known single-screw extruder, twin-screw extruder, Banbury mixer, roll mill, or the like is used. In consideration of productivity and the like, a single-screw and twin-screw extruder is preferable. After the melt mixing, a stabilizer such as a known antioxidant is added to the modified ethylene polymer to terminate the fine crosslinking reaction of the raw ethylene polymer.

The method of mixing the organic peroxide with the raw ethylene polymer is not particularly limited, but it is necessary to disperse the organic peroxide in the powder, pellet or melt of the raw ethylene polymer as uniformly as possible. In particular, a method of uniformly mixing an organic peroxide using a raw material ethylene polymer powder is most preferable. For example, a method in which an organic peroxide is dissolved in an appropriate solvent and added to a powder of the raw material ethylene polymer. Alternatively, a method using a high-concentration master batch or the like prepared by extruding an organic peroxide with an ethylene polymer at a low temperature may be used.

As an antioxidant for stopping the microcrosslinking reaction
Are phenolic stabilizers and / or organic phosphites
The stabilizer and / or the organic thioether-based stabilizer of the present invention
Add in a range that does not impair the purpose. Phenolic stability
As an agent, 2,6-di-tert-butyl-4-methylphen
Knoll, 2,6-dicyclohexyl 4-methylphen
Knoll, 2,6-diisopropyl-4-ethylphenol
2,6-zy t-amylose 4-methylphenol,
2,6-g-tert-octyl-4-n-propylphenol
2,6-dicyclohexyl 4-n-octyl
Enol, 2-isopropyl-4-methyl-6-t
Tylphenol, 2-t-butyl-2-ethyl-6-t
-Octylphenol, 2-isobutyl-4-ethyl-
6-t-hexylphenol, 2-cyclohexyl-4
-N-butyl-6-isopropylphenol, tetraki
(Methylene (3,5-di-tert-butyl-4-hydroxy)
B) Hydrocinnamate) methane, 2,2^,-Methylene bi
(4-methyl-6-t-butylphenol), 4,4^,
Butylidenebis (3-methyl-6-t-butylpheno
), 4,4^,-Thiobis (3-methyl-6-t butyl
Phenol, 2,2^,-Thiobis (4-methyl-6-
t-butylphenol), 1,3,5-trimethyl-
2,4,6 tris (3,5-zy t-butyl-4-hi
Droxyphenyl) benzylbenzene, 1,3,5
Squirrel (2-methyl-4-hydroxy-5-t-butylphenol)
Enol) methane, tetrakis (methylene (3.5
-Butyl-4-hydroxyphenyl) propionate
G) methane, β- (3,5-di-tert-butyl-4-hydr)
Roxyl phenol) alkyl propionate,
2,2^,-Oxamidobis (ethyl-3- (3.5-zy
(t-butyl-4-hydroxyphenyl) propione
G, tetrakis (methylene (2,4-g-t-butyl-
4-hydroxyl) propionate), n-octadecy
Roux 3 (4^,-Hydroxy-3,5-di-tert-butyl
Phenyl) propionate, 2,6-di-tert-butyl-
p-cresol, 2,4,6 tris (3^,, 5^,G
-Butyl-4^,-Hydroxybenzylthiono 1,3
5-triazine, 2,2^,-Methylenebis (4-methyl-
6-t-butylphenol), 4, 4^,Methylene bis
(2,6-Gee t-butylphenol), 2,2 ^,-Mechi
Lembis (6- (1-methylcyclohexyl) -palk
Resole), bis (3,5-bis (4-hydroxy-3
-T-butylphenyl) butyric acid) glycol
Ester, 4,4^,Butylidenebis (6-t-butyl
-M-cresol), 1,1,3 tris (2-methyl
-4-hydroxy-5-t-butylphenyl) butane,
1,3,5-tris (2,6-dimethyl-3-hydroxy
C4-tert-butylbenzyl) isocyanurate, 1,
3,5 tris (3,5-di-tert-butyl-4-hydro
Xybenzyl) -2,4,6-trimethylbenzene,
1,3,5 tris (3,5-z-t-butyl-4-hi
Droxybenzyl) isocyanate, 1,3,5-tri
((3.5-g t-butyl-4-hydroxyphenyl)
Le) propionyloxyethyl) isocyanurate,
2-octylthio-4,6-di (4-hydroxy-3,
5-Gee t-butyl) phenoxy-1,3,5-tria
Gin, 4, 4^,-Thiobis (6-t-butyl-m-cre
Sol) and the like.

As the organic phosphite stabilizer, trioctyl phosphite, trilauryl phosphite,
Tridecyl phosphite, octyl diphosphite,
Tris (2,4-di-tert-butylphenyl) phosphite, triphenylphosphite, tris (butoxyethyl) phosphite, tris (nonylphenyl) phosphite, distearylpentaerythritol diphosphite, tetra (tridecyl) -1,1,1 3-tris (2-methyl-5-tert-butyl-4-hydroxyphenyl) butane diphosphite, tetra (tridecyl) -4,4 ^,
-Butylidenebis (3-methyl-6-tert-butylphenol) diphosphite, tris (3,5-di-tert-butyl-4-hydroxyphenyl) phosphite, tris (mono- or dinonylphenyl) phosphite, hydrogenated-4,4 ^, -isopropylidene Dendiphenol polyphosphide, bis (octylphenyl) bis (4,4 ^, butylidenebis (3-methyl-6-t-butylphenol))
1,6-hexane-ol diphosphate sulfide, ^phenyl-4,4, chromatography isopropylidenediphenol pentaerythritol diphosphite sulfide, bis (2,4-di-t-butylphenyl) pentaerythritol diphosphite sulfide, bis (2,6-di-t-butyl-4 Methylphenyl) pentaerythritol diphosphide, tris ((4,4 ^,
-Isopropylidenebis (2-tert-butylphenol)) phosphide, di (nonylphenyl) pentaerythritol diphosphide, tris (1,3-distearoyloxyisopropyl) phosphite, 4,4 ^,
-Isopropylidenebis (2-t-butylphenol)
Di (nonylphenyl) phosphide, 9,10-dihydro-9-oxa10-phosphaphenanthrene-1
0 over oxide, tetrakis (2,4-di-t-butylphenyl) over 4,4 ^include over biphenylene phosphite sulfide and the like.

Examples of the organic thioether stabilizers include dialkylthiopropionates such as dilauryl, dimyristyl, and distearyl, and butyl, octyl, and the like.
Esters of polyhydric alcohols of alkylthiopropionic acids such as laurilu, stearyl-, etc. (eg glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, trishydroxyethyl isocyanurate) (eg, pentaerythitol tetralaurylthiopropionate) Is mentioned.

More specifically, dilauryl thiopropionate, dimyristyl thiopropionate, distearyl thiodipropionate, lauryl stearyl thiodipropionate, distearyl thiodibutyrate and the like can be mentioned. The modified ethylene polymer obtained by the above method has a melt index MI _2.16 at (D) 190 ° C. under a load of 2.16 kg of 0.1 to 0.5 g / 10.
(E) molecular weight distribution measured by gel permeation chromatography from 4 to 7, (F) density 0.95 g / c
m ³ or more, the ratio MI and the melt index MI _21.6 and MI _2.16 with 21.6kg load at 190 ° C. (G)
_21.6 / MI _2.16 is 50 or more.

The melt index MI _2.16 of the modified ethylene polymer at 190 ° C. under a load of 2.16 kg is:
0.1 to 0.5 g / 10 min, preferably 0.2 to 0.4 g / 10 min, more preferably 0.25 to 0.1 g / min.
35 g / 10 min. When the MI _2.16 is less than 0.1 g / 10, the load becomes large in the extrusion step in blow molding. When the MI _2.16 exceeds 0.5 g / 10 min, the swell required for blow molding is insufficient.

The modified ethylene polymer has a molecular weight distribution measured by gel permeation chromatography of 4 to 7, preferably 4.5 to 6.5. When the molecular weight distribution is less than 4, the swell is insufficient and blow molding is difficult, and when the molecular weight distribution exceeds 7, low molecular weight components increase and the cleanliness of the bottle decreases. The density of the modified ethylene polymer is 0.95 g / cm ³ or more, preferably 0.96 g / cm ³ . The density is 0.95g /
If it is less than ³ cm ^3, the cleanliness of the container will decrease.

Further, the modified ethylene polymer is blow-molded into the bottle of the present invention. In this blow molding method, the modified ethylene polymer satisfying the two steps of the extrusion step and the blow molding. It is necessary to have viscoelasticity of coalescence. As a measure of the viscoelasticity, the ratio of the melt flow index at different loads is used. That is, the modified ethylene polymer used in the present invention is 21.6 at 190 ° C.
The ratio of the melt index MI _21.6 to MI _2.16 under a kg load MI _21.6 / MI _2.16 needs to be 50 or more. Preferably it is 70 or more, more preferably 80 or more.

Before the blow molding, the modified ethylene polymer used in the present invention contains a phenolic stabilizer and / or an organic phosphite stabilizer and / or an organic thioether stabilizer and / or a fatty acid metal salt. It can be added within a range that does not impair the object of the invention. Also, pigments, dyes,
Additives added to polyolefins such as nucleating agents, lubricants, inorganic fillers such as carbon black, talc, and glass fibers or reinforcing materials, flame retardants, neutron blocking agents, etc. within a range that does not impair the purpose of the present invention. May be.

The modified ethylene polymer is formed into the bottle of the present invention by a forming method such as direct blow, stretch blow, and multilayer blow. The obtained bottle is particularly preferably used for medical or semiconductor high-purity reagent containers.

[0052]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described with reference to embodiments.
I do. In addition, physical property measurement is as follows. MI_2.16 According to ASTM D-1238, 190 ° C, load 2.1
This is a value measured at 6 kg. MI_21.6/ MI_2.16  Mel toy measured at a temperature of 190 ° C and a load of 21.6Kg
Index (MI_{twenty one .6}) At 190 ° C, load 2.
Measured at 16 kg, melt index (MI_{Two , 16}) Divided by
Value. The measuring device used for the molecular weight distribution measurement was 150-C manufactured by Waters.
ALC / GPC, column of AT-
807S and Tosoh TSK-gel GMH-H6
10 ppm of Irganox 101 in the solvent
Measure at 140 ° C using trichlorobenzene containing 0
Specified. A commercially available monodisperse polystyrene is used as a standard substance.
Was used to create a calibration curve. Evaluation of blow moldability Using a 50 mm diameter screw hollow molding machine, cylinder
500ml molded at a temperature of 200 ° C and a mold at 50 ° C
A round bottle (weight 40 g) was formed. Evaluation of moldability
Extrusion amount per unit time and gel on bottle surface
And the thickness irregularity of the bottle was evaluated as good, acceptable or unacceptable by visual observation. Evaluation of cleanliness Filtration of molded round bottle with 0.1μm filter
Add 150ml of ultrapure water and add 2000ml glass
Placed in a sterile container and sealed. 30 minutes at 110 ° C
1μm existing in pure water in the container after steam sterilization
The number of fine particles (cleanliness (particles / ml)
Unter (HIAC / ROYCO, Series 4100)
Was measured. All operations are performed in class 1000
We went in the lounge room.

[0053]

Example 1 Preparation of ethylene polymer 6.2 g (8.8 mmol) of triethylammonium tris (pentafluorophenyl) (4-hydroxyphenyl) borate was added to 4 l of toluene, and 9
The mixture was stirred at 0 ° C. for 30 minutes. Then add 1 mol / l to this solution
40 ml of a toluene solution of trihexylaluminum was added and stirred at 90 ° C. for 1 minute.

On the other hand, 1 g of silica P-10 (manufactured by Fuji Silysia K.K., Japan) was treated with a nitrogen stream at 500 ° C. for 3 hours, and the treated silica was placed in 500 ml of hexane and stirred. To this silica slurry solution, 5 ml of a hexane solution of triethylaluminum (concentration: 1M) was added, and the mixture was stirred for 1 hour, and unreacted triethylaluminum was decanted off to obtain 50 ml of a slurry. To this slurry was added a toluene solution of triethylammonium tris (pentafluorophenyl) (4-hydroxyphenyl) borate and trihexylaluminum, and the mixture was stirred at 90 ° C. for 3 hours.

Next, 206 ml of a 1 mol / l trihexylaluminum toluene solution was added, and 9
Stirred at 0 ° C. for 1 hour. Thereafter, the supernatant was decanted five times using toluene at 90 ° C. to remove excess trihexyl aluminum. 0.218 mol / l of dark purple titanum (N-1,1-dimethylethyl) dimethyl (1- (1,2,3,4,5, et)
a) -2,3,4,5-tetramethyl-2,4-cyclopentadien-1-yl) silanaminato) ((2-)
N) ISOPAR of chromatography (eta ⁴ over 1,3 Pentajien)
20 ml of ^TM E (Exxon Chemical Co., USA) solution was added to the above mixture and stirred for 3 hours to obtain a green supported catalyst. 0.8 l of hexane obtained by dehydrating and deoxidizing a part of the obtained supported catalyst
And into a 1.5 l reactor.

A gas mixture of ethylene, 1-butene and hydrogen (gas composition: ethylene 700
g, 1-butene 1 g, hydrogen 0.7 l) and the total pressure is 8 kg /
cm ² . By replenishing the mixed gas of the above composition,
Polymerization was carried out for 2 hours while maintaining the total pressure at 8 kg / cm ² to obtain a raw material ethylene polymer shown in Table 1. 2,5-dimethyl-2,5 is added to 100 parts by weight of the obtained raw material ethylene polymer powder.
0.1 part by weight of bis- (t-butylperoxy) hexane was added and extruded at a temperature of 230 ° C. using a single screw extruder.

Irganox 101 was added to the resulting pellet.
After adding 0,500 ppm and extruding again, a modified ethylene polymer was obtained. The obtained modified ethylene polymer was blow-molded, and the moldability was evaluated. The moldability is good, and the appearance and cleanliness of the bottle are also excellent.

[0058]

Examples 2 to 4 The starting ethylene polymers of Examples 2 to 4 were produced according to the production method of Example 1 except that the amount of butene-1 and the amount of hydrogen were changed. The starting ethylene polymer was finely crosslinked in the same manner as in Example 1 by using the modification method shown in Table 1.
The resulting modified ethylene polymer was blow molded. The obtained bottle is excellent in appearance and cleanness, and has no problem in moldability.

[0059]

Comparative Examples 1 to 5 The raw ethylene polymers of Comparative Examples 1 to 5 were produced according to the production method of Example 1 except that the amount of butene-1 and the amount of hydrogen were changed. The obtained raw ethylene polymer was modified to form a bottle. In Comparative Example 1, even if the raw material ethylene polymer had a low MI _2.16, sufficient moldability could not be ensured, and the appearance of the bottle was poor.

In Comparative Example 2, the MI _2.16 of the raw material was high, and as a result, the cleanliness of the bottle was reduced. In Comparative Example 3, the amount of the organic peroxide was too small and the organic peroxide was not sufficiently modified, so that a uniform bottle could not be formed. In Comparative Example 4, the amount of the organic peroxide was too large, the crosslinking was too advanced, and a large amount of gel was generated on the bottle surface. In Comparative Example 5, the density of the raw ethylene polymer was low and the cleanliness of the bottle was low.

[0061]

Comparative Example 6 Ethylene Polymer Using Ziegler Catalyst The raw ethylene polymer was polymerized using a known Ziegler catalyst prepared from magnesium chloride hexahydrate, 2-ethylhexanol, and magnesium chloride, and was further finely crosslinked. Was. The obtained bottle has poor cleanliness. This is because the raw ethylene polymer has a wide molecular weight distribution and contains many low molecular weight components.

[0062]

Comparative Example 7 Zirconocene-Catalyzed Ethylene Copolymer Silica (Grand 952, manufactured by Fuji Devison Co., Ltd.) was placed in a 200 ml flask which had been sufficiently dried with nitrogen.
g and toluene (40 ml) were added and cooled to -40 ° C.
30 ml of a toluene solution of methylalumoxane (MMAO-3 manufactured by Tosoh Akzo Co., Ltd.) was added and reacted for 1 hour. Thereafter, the reaction was carried out at 0 ° C. for 1 hour, further at 80 ° C. for 3 hours, and cooled to 20 ° C. after completion of the reaction. Thus, a silica carrier supporting methylalumoxane was obtained. Next, 1 μmol of 2.5 ml / liter of a toluene solution of bis (n-butylcyclopentadienyl) zirconium dichloride in terms of zirconium and 0.12 mmol of triisobutylaluminum (1.0 mol / liter) were added,
The catalyst was synthesized.

The resulting suspension was deaerated and deoxygenated, and the inside thereof was vacuum-degassed together with 0.8 l of hexane and placed in a 1.5 l reactor purged with nitrogen. 75 ° C inside container
The amount of a mixed gas of ethylene, 1-butene and hydrogen was adjusted as follows (gas composition: ethylene 700 g, 1-butene 2
g, hydrogen 0.5 l) to a total pressure of 8 kg / cm ² .
By supplying the mixed gas, polymerization was carried out for 2 hours while maintaining the total pressure at 10 kg / cm ² to obtain a raw ethylene polymer. The obtained ethylene polymer was modified and blow-molded. However, this modified ethylene polymer was particularly deficient in swell and the bottle was non-uniform.

[0064]

[Table 1]

[0065]

The clean ethylene polymer bottle using the specific modified ethylene polymer of the present invention is superior in cleanliness to the conventional one.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08L 23/26 C08L 23/26 // B29K 23:00 105: 24 B29L 22:00

Claims (5)

[Claims] 1. A melt index MI _2.16 at a load of 2.16 kg at 190 ° C. of 0.8 to 5 g / 10
(B) the molecular weight distribution measured by gel permeation chromatography is 3 to 5, and (C) the density is 0.95 g / c.
m ³ or more, 100 to 100 parts by weight of a raw material ethylene polymer, 0.01 to 0.3 parts by weight of an organic peroxide was added and melt-mixed, and the obtained (D) was obtained at 190 ° C. under a load of 2.16 kg. Melt index MI _2.16 from 0.1 to 0.5
g / 10 min, (E) the molecular weight distribution measured by gel permeation chromatography is 4 to 7, and (F) the density is 0.9.
5 g / cm ³ or more, (G) 21.6 k at 190 ° C.
A clean ethylene polymer bottle obtained by blow molding a modified ethylene polymer having a ratio of melt index MI _21.6 to MI _2.16 at g load of MI _21.6 / MI _2.16 of 50 or more. 2. The clean ethylene polymer bottle according to claim 1, wherein a dialkyl peroxide is used as the organic peroxide. 3. A modified ethylene polymer comprising (a) a carrier substance, (a) an organic aluminum compound, (c) a borate compound having active hydrogen, (d) cyclopentadienyl or a substituted cyclopentadienyl group. The clean ethylene polymer bottle according to claim 1, wherein the raw material ethylene polymer in a slurry state is modified by using a supported catalyst prepared from an η-bonded titanium compound. . 4. The clean ethylene polymer bottle according to claim 1, which is formed by direct blow molding. 5. The clean ethylene polymer bottle according to claim 1, wherein the bottle is used for a medicine container and a semiconductor cleaning reagent container.