JP3532106B2 - Polyethylene silane cross-linked pipe - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a silane crosslinked pipe molded by using a specific ethylene polymer. More specifically, using an ethylene homopolymer having a specific molecular weight distribution, density, and melt viscosity, or a copolymer of ethylene and an α-olefin, an organic peroxide, an organic unsaturated silane compound, and a silanol condensation catalyst are used. It relates to a crosslinked silane crosslinked pipe.

[0002]

2. Description of the Related Art At present, vinyl chloride pipes are used as water supply pipes for houses, and copper pipes are mainly used as hot water supply pipes. Conventional vinyl chloride pipes and copper pipes have a problem that they have a short service life, and in particular, copper pipes cause blue water, colored water such as red water, and water leakage due to rust. Further, since the copper pipe has a drawback that the contract workability is poor, a crosslinked polyolefin pipe is being used in recent years. Compared to uncrosslinked polyethylene pipes, crosslinked polyethylene pipes have significantly improved creep characteristics at high temperatures, and are superior to vinyl chloride pipes and copper pipes in terms of durability and also in workability. For this reason, cross-linked polyethylene pipes are said to be promising for water supply, hot water supply, and heating pipes.

As a typical method for producing a crosslinked polyethylene pipe, a resin composition prepared by blending polyethylene with an organic peroxide such as dicumyl peroxide is disclosed in Japanese Patent Publication No. 45658/1985. A method of extruding into a pipe shape while heating at a temperature equal to or higher than the decomposition temperature of the oxide is disclosed. In this process, the organic peroxide is thermally decomposed into an organic radical, and a radical is generated in polyethylene by the action of this organic radical, and the crosslinking of polyethylene proceeds through the radical. As another typical method, polyethylene is mixed with a silane compound such as vinylethoxysilane, an organic peroxide and a silanol condensation catalyst, and the obtained composition is extruded into a pipe while being heated. The exposed pipe is exposed to a moist environment to promote silane crosslinking.

Further, JP-A-7-258496 discloses a cross-linked molded article comprising a fluorine-containing resin, a silane-modified olefin polymer and a graft ethylene polymer, and JP-A-8-73.
No. 670 discloses a cross-linked polyethylene composition comprising a copolymer of ethylene and butene-1 having a specific melt index, and JP-A-9-25367 discloses a cross-linked polyolefin pipe comprising a composition comprising a polyolefin and vitamin E. Japanese Patent Application Laid-Open No. 9-324081 discloses a cross-linked polyethylene pipe composed of polyolefin and a specific antioxidant, and Japanese Patent Application Laid-Open No. 10-17625 discloses a cross-linked polyolefin pipe using polyolein obtained from a Phillips catalyst. JP-A-3-1709031 discloses a cross-linked pipe using a polyolefin containing a large amount of double bonds, JP-A-60-2351 discloses a cross-linked pipe to which activated carbon is added, and JP-A-57-170913 discloses a specific pipe. Cross-linked pipe using polyethylene having a density and a molecular weight, JP-A-9-242 20867 and No. Hei 7 -15
7568 discloses a cross-linked pipe using silane-modified graft polyethylene having a narrow molecular weight distribution,

JP-A-7-41610 discloses a cross-linking pipe for drinking water using a special organic peroxide, and JP-A-2-2.
Japanese Patent No. 53076 discloses a cross-linked pipe using a water-releasing substance,
JP-A-60-1252 discloses a crosslinked pipe containing activated carbon, silica and alumina, and JP-A-10-182757.
JP-A-5-163364 discloses a water supply and hot water supply pipe using a specific organic unsaturated silane and a specific radical generator.
Japanese Patent Application Laid-Open No. 7-330992 discloses a polyolefin pipe to which a special weathering agent is added, Japanese Patent Application Laid-Open No. 6-248033 discloses a resin composition containing polyolefin, an organic unsaturated silane, and a specific free radical generator. A method of adding an epoxy compound is disclosed in JP-A-6-248089.
In JP-A No. 57-59724 and JP-A No. 60-84322, a polyolefin pipe is once molded and then crosslinked by passing an aqueous silanol condensation catalyst solution. Method, JP-A-5
8-65388 discloses a chlorine-containing water transportation pipe.

However, the raw material polyethylenes used in the above-mentioned prior art are all ethylene polymers polymerized by a Ziegler polymerization catalyst or a Phillips type polymerization catalyst. Various problems arise in the above-mentioned attempts using these conventional ethylene polymers. That is, when a conventional ethylene polymer having a broader molecular weight distribution and a larger amount of comonomer inserted in the lower molecular weight component is used, crosslinking proceeds in the lower molecular weight component, while the higher molecular weight component is not sufficiently crosslinked. Therefore, the mechanical strength of the silane crosslinked pipe, especially the hot internal pressure creep property is poor. On the other hand, it is necessary to add a large amount of unsaturated silane compound in order to sufficiently promote silane crosslinking even in the high molecular weight component. When water is passed through the silane cross-linked pipe molded in this way, problems such as unpleasant odor derived from unsaturated silane compounds, etc. occur, and a large amount of eye bleeding also occurs during extrusion molding of the pipe. Long-term molding operation becomes difficult. Moreover, the hot internal pressure creep characteristics are not satisfactory.

In recent years, it has been attempted to produce an ethylene polymer having a molecular weight distribution of 2 to 3 by using a catalyst prepared from a metallocene compound and an aluminoxane, etc., JP-A-58-19309, 60-35006 and 60-. -35
007, ibid. 61-130314, ibid. 61-22120
No. 8, No. 62-121709, No. 62-121711 and the like. JP-A-10-193468
In the publication, a crosslinked pipe using polyethylene obtained with a metallocene catalyst is disclosed, but in the case of this ethylene polymer, it is preferable in terms of a uniform crosslinked product, but the molecular weight distribution is narrow, especially in the extrusion process of the pipe, Due to insufficient fluidity, heat generation in the extruder becomes large and premature cross-linking occurs partially. As a result, the surface condition of the extruded pipe deteriorates and the mechanical strength decreases. The polyethylene used in this publication has a long chain branch in the molecule, and sufficient mechanical properties, especially hot internal pressure creep properties can be obtained even if polyethylene having such a long chain branch is cross-linked. Absent.

[0008]

DISCLOSURE OF THE INVENTION The present invention is to solve the above-mentioned problems, and it is an ethylene homopolymer having specific characteristics, or a copolymer of ethylene and α-olefin, an organic peroxide, and an organic peroxide. Provided is a silane crosslinked pipe obtained by crosslinking a composition comprising a saturated silane compound with a silanol condensation catalyst. The silane cross-linked pipe of the present invention has excellent mechanical properties, has little odor during passage of water, and has no problems such as increased load on the extruder, heat generation, and eyesight during pipe molding.

[0009]

Means for Solving the Problems As a result of diligent studies, the present inventors have found that a pipe having excellent extrusion moldability and having a molded pipe grafted onto an ethylene polymer by hot water or steam in the presence of a silanol condensation catalyst. It was found that the silane cross-linked pipe obtained by cross-linking existing silane groups has excellent properties. That is, the present invention is: (1) 100 parts by weight of an ethylene homopolymer having the following characteristics (A) to (D) or a copolymer of ethylene and α-olefin, (A) a load of 2.16 kg at 190 ° C. Has a melt index (MI2.16) of 0.5 to 10 g / 10 min (B), the molecular weight distribution measured by gel permeation chromatography is 3 to 6 (C), the density is 0.925 g / cm ³ or more (D) 200. C., viscosity (.eta.100) under shear rate of 100 rad / s is 2000 Pa.s. s or less (2) 0.005 to 5 parts by weight of organic peroxide, (3) 0.1 to 10 parts by weight of an organic unsaturated silane compound, a silane crosslink obtained by crosslinking with a silanol condensation catalyst. Regarding pipes.

The present invention will be described in detail below. The 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, eicosene-1. Etc. can be used. Further, vinyl compounds such as vinylcyclohexane or styrene and its derivatives can also be used. Butene-1, hexene-1, and octene-1 are particularly preferred. It may be a ternary random polymer containing a small amount of non-conjugated polyene such as 1,5-hexadiene and 1,7-octadiene, if necessary.

The amount of insertion of these α-olefins is ethylene.
Density of copolymer is 0.925g / cm ³Above, silane cross-linking
When the pipe is applied to the sheathing method etc., preferably
0.930-0.944 g / cm³, And more preferably
0.935 to 0.942 g / cm³In the range of
It The density here was obtained when measuring the melt index.
Heat the strands at 100 ° C for 1 hour and
Measured with a density gradient tube after allowing to cool for 1 hour.
It Density is 0.925g / cm³If less than α-ole
Intramolecular insertion of the tertiary carbon generated by fin insertion
Becomes non-uniform, silane cross-linking progresses non-uniformly,
The mechanical strength and appearance of the bridge pipe are poor. Low density
In the case of the silane cross-linked pipe, the oxidation is prevented when passing water at high temperature.
The agent elutes from the silane cross-linked pipe,
There is a problem that the long-term oxidation resistance decreases.

The melt index (MI2.) Of the ethylene homopolymer or the copolymer of ethylene and α-olefin used in the present invention at 190 ° C. under a load of 2.16 kg.
16) is 0.5 to 10 g / 10 minutes, preferably 1 to 8 g
/ 10 minutes, more preferably 2 to 7 g / 10 minutes. When MI2.16 is less than 0.5 g / 10 min, extrusion molding of the pipe is difficult, and when it exceeds 10 g / 10 min, the obtained silane-crosslinked pipe has insufficient mechanical strength. The molecular weight distribution (Mw / M) of the ethylene homopolymer used in the present invention or the copolymer of ethylene and α-olefin is also used.
n) has a molecular weight distribution measured by gel permeation chromatography of 3 to 6, preferably 3.5 to 5.5. When the molecular weight distribution is less than 3, pipe extrusion is difficult. When the molecular weight distribution exceeds 6, there is a problem that the low molecular weight component in the polymer is crosslinked and the polymer component is not sufficiently crosslinked. The measuring device used for the measurement of gel permeation chromatography is W
Athers 150-C, ALC / GPC, and Shodex AT-807S and Tosoh T as columns.
SK-gelGMH-H6 was used in series, trichlorobenzene was used as the solvent, and the measurement was performed at 140 ° C.

The ethylene homopolymer or the copolymer of ethylene and α-olefin used in the present invention has good pipe extrusion moldability. That is, 200 ℃, 100 rad /
Viscosity (η100) under shear rate at 2000s is 2000P
a. s or less, preferably 1800P
a. s or less, more preferably 1600 Pa.s. s or less. This viscosity is 20000 Pa.s. If it exceeds s, it is difficult to extrude the pipe, the surface of the pipe becomes rough, and the resin temperature rises due to the heat generated during extrusion of the pipe, resulting in a non-uniform crosslinking reaction. Mechanical strength is reduced.

Such ethylene homopolymer or ethylene / α-olefin copolymer has a melt index MI21.6 at 190 ° C. under a load of 21.6 kg.
And the melt index MI2.16 under a load of 2.16 kg at 190 ° C., the ratio MI21.6 / MI2.16 is preferably 17 to 38, more preferably 18 to 26, and most preferably 19 to 23. This MI21.6 / MI2.16 is an index for evaluating the shear rate dependence of the melt viscosity of the ethylene polymer. The higher this index, the easier the extrusion molding of the pipe. Mechanical properties deteriorate.

Next, a method for producing an ethylene homopolymer or ethylene / α-olefin copolymer having the characteristics (A) to (D) will be described. The ethylene homopolymer or copolymer used in the present invention is, for example, at least (a)
A catalyst that reacts with a carrier material, (a) an organoaluminum compound, (c) a transition metal compound having a cyclic η-bonding anion ligand, and (d) a transition metal compound having a cyclic η-bonding anion ligand Obtained by homopolymerizing ethylene or copolymerizing ethylene with an α-olefin having 3 to 20 carbon atoms, using a supported catalyst prepared from an activator capable of forming an activity-expressing complex.

(A) The carrier substance may be either an organic carrier or an inorganic carrier. The organic carrier is preferably (1) an α-olefin (co) having 2 to 10 carbon atoms.
Polymers such as polyethylene, polypropylene, polybutene-1, ethylene-propylene copolymer, ethylene-butene-1 copolymer, ethylene-hexene-1 copolymer, propylene-butene-1 copolymer, propylene-divinylbenzene Copolymer, (2) aromatic unsaturated hydrocarbon polymer such as polystyrene, styrene-divinylbenzene copolymer, and (3) polar group-containing polymer such as polyacrylic acid ester, polymethacrylic acid ester, Examples thereof include polyacrylonitrile, polyvinyl chloride, polyamide and polycarbonate.

Examples of the inorganic carrier include (4) inorganic oxides, eg
For example, SiO₂, Al₂O₃, MgO, TiO₂, B₂
O₃, CaO, ZnO, BaO, ThO, SiO₂-M
gO, SiO₂-Al₂O₃, SiO₂-MgO, Si
O₂-V₂O_FiveEtc. (5) Inorganic halogen compounds, eg
For example, MgCl₂, AlCl₃, MnCl₂Etc. (6) None
Machine carbonates, sulphates, nitrates, eg Na₂CO₃,
K₂CO₃, CaCO₃, MgCO₃, Al₂(S
O_Four)₃, BaSO_Four, KNO₃, Mg (NO₃)
₂Etc. (7) Hydroxide, eg Mg (OH)₂, Al
(OH)₃, Ca (OH) ₂Etc. are illustrated. Most preferred
The preferred carrier material is silica. The particle size of the carrier is arbitrary
However, generally 1 to 3000 μm, preferably 5 to 20
00 μm, more preferably 10 to 1000 μm
Is.

The above carrier material is optionally treated with (a) an organoaluminum compound. Examples of preferred organoaluminum compounds include trimethylaluminum, triethylaluminum, triisobutylaluminum,
Alkyl aluminum such as trihexyl aluminum, trioctyl aluminum, tridecyl aluminum; diethyl aluminum monochloride, diisobutyl aluminum monochloride, ethyl aluminum sesquichloride, ethyl aluminum dichloride, diethyl aluminum hydride, diisobutyl aluminum hydride, etc. alkyl aluminum hydride; diethyl aluminum Aluminum alkoxides such as ethoxide, dimethyl aluminum methoxide and dimethyl aluminum phenoxide; alumoxanes such as methyl alumoxane, ethyl alumoxane, isobutyl alumoxane and methyl isobutyl alumoxane. Of these, trialkylaluminum,
Aluminum alkoxide and the like are preferable. Most preferred are trimethylaluminum, triethylaluminum and triisobutylaluminum.

The supported catalyst of the present invention is (c) a transition metal compound having a cyclic η-bonding anion ligand (hereinafter, may be simply referred to as "transition metal compound" in the present invention).
including. The transition metal compound of the present invention can be represented by, for example, the following general formula (1).

## STR00001 ## L1 MXp X'q (1) In the formula, M is an η5 bond with one or more ligands L, and a transition metal of Group 4 of the periodic table having an oxidation number of +2, +3 or +4. Is.

L is a cyclic η-bonding anion ligand, and each independently represents a cyclopentadienyl group, an indenyl group, a tetrahydroindenyl group, a fluorenyl group, a tetrahydrofluorenyl group, or octahydrofluorene group. Nyl groups, which are hydrocarbon groups containing up to 20 non-hydrogen atoms, halogens, halogen-substituted hydrocarbon groups, aminohydrocarbyl groups, hydrocarbyloxy groups, dihydrocarbylamino groups, hydrocarbylphosphino groups, silyl groups. , An aminosilyl group, a hydrocarbyloxysilyl group, and a halosilyl group, each optionally having 1 to 8 substituents, and further, two Ls are hydrocarbas containing up to 20 non-hydrogen atoms. Diyl, halohydrocarbadiyl, hydrocarbyleneoxy, hydrocarbi N'amino, siladiyl, Haroshirajiiru, may be linked by a divalent substituent of aminosilane or the like.

X is independently a monovalent anionic σ-bonding ligand having up to 60 non-hydrogen atoms, a divalent anionic σ-bonding ligand binding divalently with M, Alternatively, it is a divalent anionic σ-bonding ligand that binds to M and L with a valency of 1 each. X ′ is each independently a neutral Lewis base coordinating compound having 4 to 40 carbon atoms and selected from phosphine, ether, amine, olefin, and / or conjugated diene. Also, l is an integer of 1 or 2. p is an integer of 0, 1, or 2, and X is a monovalent anionic σ-bonding ligand or a divalent anionic σ-bonding ligand that binds to M and L with a valency of 1 each. As a child, p is less than the formal oxidation number of M by 1 or more, and X is M
When it is a divalent anionic σ-bonding ligand that binds divalently with, p is 1 + 1 or more less than the formal oxidation number of M. Also,
q is 0, 1 or 2. As the transition metal compound,
It is preferable that l = 1 in the general formula (1).

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

[Chemical 2] In the formula, M is titanium, zirconium, or hafnium having a formal oxidation number of +2, +3, or +4. R ³ is independently hydrogen, a hydrocarbon group, a silyl group, a germyl group,
A cyano group, a halogen, or a composite group thereof, each of which can have up to 20 non-hydrogen atoms, and adjacent R ^{3 s} are combined to form a divalent derivative such as hydrocarbadiyl, siladiyl, or germanadiyl. May be formed into a ring shape.

X "is independently a halogen, a hydrocarbon group,
Hydrocarbyloxy group, hydrocarbylamino group,
Or silyl group, each having up to 20 non-hydrogen atoms
And two X "are neutral covalent carbon atoms of 5 to 30
A role diene or a divalent derivative may be formed. Y is
-O-, -S-, -NR^*-,-PR^*− And Z is
SiR^* ₂, CR ^* ₂, SiR^* ₂SiR^* ₂, CR^*
₂CR^* ₂, CR^*= CR^*, CR^* ₂SiR^* ₂Also
Is GeR^* ₂And where R^*Each independently has 1 carbon
To 12 alkyl or aryl groups. Also,
n is an integer of 1 to 3.

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

[Chemical 3] Or

[Chemical 4]

In the formula, each R ³ independently represents hydrogen, a hydrocarbon group, a silyl group, a germyl group, a cyano group, a halogen, or a composite group thereof, and each can have up to 20 non-hydrogen atoms. . In addition, M is titanium, zirconium or hafnium. Z, Y, X and X ′ are the same as the above definitions. p is 0, 1 or 2,
Further, q is 0 or 1. However, when p is 2 and q is 0, the oxidation number of M is +4 and X is halogen, a hydrocarbon group, a hydrocarbyloxy group, a dihydrocarbylamide group, a dihydrocarbylphosphide group, a hydrocarbyl sulfide group, a silyl group. Or these complex groups,
It has up to 20 non-hydrogen atoms.

When p is 1 and q is 0, the oxidation number of M is +3 and X is an allyl group, 2- (N, N-dimethylaminomethyl) phenyl group or 2- (N, N- Is a stabilized anion ligand selected from dimethyl) -aminobenzyl group, or the oxidation number of M is +4 and X
Is a derivative of a divalent conjugated diene, or M and X
Together form a metallocyclopentene group. Also,
When p is 0 and q is 1, the oxidation number of M is +2, and X ′ is a neutral conjugated or non-conjugated diene, which may be optionally substituted with one or more hydrocarbon groups. Also, the X ′ can contain up to 40 carbon atoms and forms a π-type complex with M.

Further, in the present invention, the most preferable examples of the transition metal compound are the following general formulas (5) and (6).
It is represented by.

[Chemical 5] Or

[Chemical 6]

In the formula, each R ³ is independently hydrogen or an alkyl group having 1 to 6 carbon atoms. In addition, M is titanium, and Y is -O-, -S-, -NR ^* -, -PR ^* -.
Is. Z ^* is _{^{SiR * 2, CR * 2,}} SiR * 2 Si
R ^* ₂ , CR ^* ₂ CR ^* ₂ , CR ^* = CR ^* , CR ^* ₂
SiR ^* ₂ or GeR ^* ₂ , each R ^* independently represents hydrogen, a hydrocarbon group, a hydrocarbyloxy group, a silyl group, a halogenated alkyl group, a halogenated aryl group or a composite group thereof, R ^* can have up to 20 non-hydrogen atoms, and optionally Z
^* Two R ^* each other or Z ^* medium R ^* and R in Y, medium
^* And may be combined to form a ring.

P is 0, 1 or 2, and q is 0 or 1. However, when p is 2 and q is 0, the oxidation number of M is +
4 and X are each independently a methyl group or a benzyl group. When p is 1 and q is 0, the oxidation number of M is +3.
And X is 2- (N, N-dimethyl) aminobenzyl, or the oxidation number of M is +4 and X is 2-butene-1,4-diyl. If p is 0 and q
Is 1, the oxidation number of M is +2 and X ′ is 1,4-
It is diphenyl-1,3-butadiene or 1,3-pentadiene. The above-mentioned dienes exemplify asymmetric dienes that form a metal complex, and are actually a mixture of geometric isomers.

The metallocene catalyst of the present invention is
(D) An activator capable of reacting with a transition metal compound to form a complex exhibiting catalytic activity (hereinafter, may be simply referred to as “activator” in the present invention). Usually, in metallocene catalysts, the complex formed by the transition metal compound and the activator exhibits high olefin polymerization activity as a catalytically active species. In the present invention, examples of the activator include compounds defined by the following general formula (7).

[L-H] d + [Mm Qp] d -... (7) In the formula, [L-H] d + is a proton-providing Bronsted acid and L is a neutral Lewis base. .

In the formula, [Mm Qp] d- is a compatible non-coordinating anion, M is a metal or metalloid selected from Groups 5 to 15 of the periodic table, and Q is independent of each other. Hydride, dialkylamide group, halide, alkoxide group, allyloxide group, hydrocarbon group, carbon number 20
Up to 1 are substituted hydrocarbon groups, and Q, which is a halide, is 1 or less. Further, m is an integer of 1 to 7, and p
Is an integer of 2 to 14, d is an integer of 1 to 7, and pm = d.

In the present invention, more preferable examples of the activator are compounds defined by the following general formula (8).

[L-H] d + [Mm Qn (Gq (T-H) r) z] d -... (8) where [L-H] + is a proton-providing Bronsted acid. And L is a neutral Lewis base. In the formula, [Mm Qn (Gq (T-H) r) z] d- is a compatible non-coordinating anion, and M is a metal or metalloid selected from Groups 5 to 15 of the periodic table. And Q is independently a hydride, a dialkylamide group, a halide, an alkoxide group, an allyloxide group, a hydrocarbon group, or a carbon number of 20.
Up to 1 are substituted hydrocarbon groups, and Q, which is a halide, is 1 or less. Also, G is r + 1 which is connected to M and T
Is a polyvalent hydrocarbon group having a valence of, T is O, S, N
R, or PR, where R is hydrocarbyl, trihydrocarbylsilyl group, trihydrocarbyl germanium group, or hydrogen. Further, m is an integer of 1 to 7, n is an integer of 0 to 7, q is an integer of 0 or 1, r is an integer of 1 to 3, and z is 1 to 8
Is an integer, d is an integer of 1 to 7, and n + z-m
= D.

Further preferred examples of the activator are represented by the following general formula (9).

[L-H] + [BQ3Q ^* ] -... (9) In the formula, [L-H] + is a proton-providing Bronsted acid and L is a neutral Lewis base. In the formula, [BQ3Q ^* ]-is a compatible non-coordinating anion,
B represents a boron element, Q is a pentafluorophenyl group, and Q ^* has 6 carbon atoms having one OH group as a substituent.
To 20 substituted aryl groups.

Specific examples of the compatible non-coordinating anion of the present invention include, for example, triphenyl (hydroxyphenyl) borate and diphenyl-di (hydroxyphenyl).
Borate, triphenyl (2,4-dihydroxyphenyl) borate, tri (p-tolyl) (hydroxyphenyl) borate, tris (pentafluorophenyl) (hydroxyphenyl) borate, tris (2,4-dimethylphenyl) (hydroxyphenyl) ) Borate, tris (3,5-dimethylphenyl) (hydroxyphenyl)
Borate, tris (3,5-di-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-2-naphthyl) borate And the like, and most preferably tris (pentafluorophenyl) (hydroxyphenyl) borate.

Other preferred examples of compatible non-coordinating anions include those in which the hydroxy group of the above borate is NH.
Included are borate substituted with R groups. here,
R is preferably a methyl group, an ethyl group or tert-
It is a butyl group. Specific examples of the proton-providing Bronsted acid include, for example, triethylammonium, tripropylammonium, tri (n-butyl) ammonium, trimethylammonium, tributylammonium and tri (n-octyl) ammonium, diethylmethylammonium, Dibutylmethylammonium, dibutylethylammonium, dihexylmethylammonium, dioctylmethylammonium, didecylmethylammonium, didodecylmethylammonium,
Trialkyl group-substituted ammonium cations such as ditetradecylmethylammonium, dihexadecylmethylammonium, dioctadecylmethylammonium, diicosylmethylammonium, bis (hydrogenated tallowalkyl) methylammonium, and the like, and also,
N, N-dimethylanilinium,

N, N-diethylanilinium, N, N-
Also suitable are N, N-dialkylanilinium cations such as 2,4,6-pentamethylanilinium, N, N-dimethylbenzylanilinium and the like. In addition,
Dialkylammonium cations such as (i-propyl) ammonium, dicyclohexylammonium and the like are also suitable, and triaryls such as triphenylphosphonium, tri (methylphenyl) phosphonium, tri (dimethylphenyl) phosphonium and the like. A phosphonium cation, or dimethylsulfonium,
Diethyl fluphonium, diphenyl sulfonium and the like are also preferable, and further, triphenyl carbonium ion, diphenyl carbonium ion, cycloheptatrinium, indenium and the like are also preferable.

In the present invention, an organometallic oxy compound having a unit represented by the following formula (10) can also be used as an activator.

[Chemical 10] However, M ² is a metal or metalloid of Groups 13 to 15 of the Periodic Table, and R is independently a carbon number of 1 to 1.
2 is a hydrocarbon group or a substituted hydrocarbon group, n is a metal M
A ^second valence, m is an integer of 2 or more.

A preferred example of the activator of the present invention is an organoaluminum oxy compound containing a unit represented by the following formula (11).

[Chemical 11] However, R is an alkyl group having 1 to 8 carbon atoms, and m is 2
Is an integer from 60 to 60.

The most preferable example of the activator of the present invention is methylalumoxane containing a unit represented by the following formula (12).

[Chemical 12] However, m is an integer of 2 to 60. In the present invention,
In addition to the above (a) to (d) catalyst components, an organoaluminum compound can be used as a catalyst component, if necessary. The organoaluminum compound of the present invention is, for example, a compound represented by the following formula (13).

Embedded image AlR _n X _3-n (13) (wherein R is an alkyl group having 1 to 12 carbon atoms, an aryl group having 6 to 20 carbon atoms, and X is a halogen, hydrogen or an alkoxyl group. And the alkyl group is linear, branched or cyclic, and n is an integer of 1 to 3.) The organoaluminum compound of the present invention has the above general formula (1).
It may be a mixture of compounds represented by 3).

The catalyst used in the present invention can be obtained by loading the component (a) with the component (a), the component (c) and the component (d), and the component (a) is loaded with the component (d). Although the method is arbitrary, in general, the component (a), the component (c) and the component (d) are dissolved in an inert solvent in which each of them can be dissolved and mixed with the component (a), and then the solvent is added. Method of distilling off, component (a), component (c) and component (d)
After being dissolved in an inert solvent, the solution is concentrated within a range in which solid does not precipitate, and then the component (a) is added in such an amount that the total amount of the concentrated solution can be retained in the particles. Examples include a method of first supporting (a) and component (d) and then supporting component (c), a method of sequentially supporting component (a) and component (d) and component (c). To be done. The components (c) and (d) of the present invention are generally liquids or solids. In the present invention, the components (a), (c) and (d) may be used by diluting them with an inert solvent during loading.

As the inert solvent used for this purpose,
For example, propane, butane, pentane, hexane, heptane, octane, decane, dodecane, kerosene and other aliphatic hydrocarbons; cyclopentane, cyclohexane, methylcyclopentane and other alicyclic hydrocarbons; benzene, toluene,
Aromatic hydrocarbons such as xylene; and ethyl chloride,
Examples thereof include halogenated hydrocarbons such as chlorobenzene and dichloromethane, and mixtures thereof. It is desirable to use such an inert hydrocarbon solvent after removing impurities such as water, oxygen, and sulfur by using a desiccant, an adsorbent, or the like.

Component (a) is 1 × 10 ^-5 to 1 × 10 ^-1 mol, preferably 1 × 10 ^{-4 to} 5 × 10 ^-2 mol, in terms of Al atom, per gram of component (a). (C) is 1 x 10
^-7 to 1 x 10 ^-3 mol, preferably 5 x 10 ^{-7 to} 5 x 10
^-4 mol, component (D) is in the range of 1 × 10 ⁻⁷ to 1 × 10 ⁻³ mol, preferably 5 × 10 ^{−7 to} 5 × 10 ⁻⁴ mol. The amount of each component used and the loading method are determined by activity, economy, powder properties, scale in the reactor, and the like.
The obtained supported catalyst may be washed by a method such as decantation or filtration using an inert hydrocarbon solvent for the purpose of removing the organoaluminum compound, the borate compound and the titanium compound which are not supported on the carrier. it can.

The above series of operations such as dissolution, contact, washing, etc.
It is recommended to carry out at a temperature in the range of -30 ° C to 150 ° C selected for each unit operation. A more preferable range of such temperature is 0 ° C. or higher and 100 ° C. or lower. The 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 in which it is dispersed in an inert hydrocarbon solvent, or can be dried and stored in a solid state.

For the polymerization of the ethylene homopolymer or the copolymer of ethylene and α-olefin, known polymerization methods such as slurry polymerization method and gas phase polymerization method can be used. When the polymerization is carried out in the present invention, the polymerization pressure is generally 1 to 100 atm, preferably 3 to 30 atm,
The polymerization temperature is preferably 20 ° C to 115 ° C, preferably 50 ° C to 90 ° C. A slurry polymerization method is particularly suitable for achieving the object of the present invention. When using the slurry polymerization method in the present invention, the upper limit of the temperature is the temperature at which the produced ethylene homopolymer or copolymer can substantially maintain the slurry state. The molecular weight distribution of the copolymer is less than 3. As the solvent used in the slurry polymerization method, the inert hydrocarbon solvent described above in the present invention is preferable, and isobutane, isopentane, heptane, hexane, octane and the like are particularly preferable.

The comonomer which can be used in the present invention is an α-olefin represented by the following general formula. H ^₂ C = CHR ₂ (wherein, R ² is an alkyl group or an aryl group having 6 to 20 carbon atoms having 1 to 18 carbon atoms, the alkyl group is linear,
It is branched or annular. )

Examples of such comonomers include:
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, The cycloolefin having 3 to 20 carbon atoms, which is selected from the group consisting of vinylcyclohexane and styrene, is, for example, cyclopentene, cycloheptene, norbornene, 5-methyl-2-
Norbornene, tetracyclododecene, and 2-methyl-1.4,5.8-dimethano-1,2,3,4,4a,
5,8,8a-octahydronaphthalene is selected from the group consisting of linear, branched, or cyclic dienes having 4 to 20 carbon atoms, such as 1,3-butadiene, 1,4-pentadiene, and 1,5. -Selected from the group consisting of hexadiene, 1,4-hexadiene, and cyclohexadiene.
In the present invention, especially propylene, 1-butene, 1
-Pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1
-Eicosen 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 in order to prevent poisoning of the solvent and the reaction system, an organoaluminum compound coexists as an additional component. It is also possible to use it. Examples of preferable organoaluminum compounds include trimethylaluminum, triethylaluminum, triisobutylaluminum, trihexylaluminum, trioctylaluminum, tridecylaluminum, and other alkylaluminums; diethylaluminum monochloride, diisobutylaluminum monochloride, ethylaluminum sesquichloride,
Alkyl aluminum hydrides such as ethyl aluminum dichloride, diethyl aluminum hydride, and diisobutyl aluminum hydride; aluminum alkoxides such as diethyl aluminum ethoxide, dimethyl aluminum trimethyl siloxide, and dimethyl aluminum phenoxide; methyl alumoxane, ethyl aluminxane, isobutyl aluminxane, methyl Examples thereof include alumoxane such as isobutyl alumoxane. Of these, trialkylaluminum and aluminum alkoxide are preferable. Most preferred are trimethylaluminum, triethylaluminum and triisobutylaluminum.

Among the ethylene homopolymers or the copolymers of ethylene and α-olefins obtained by the above-mentioned production method, particularly in the present invention, ethylene homopolymers which do not substantially have long chain branching in the polymer. Alternatively, a copolymer of ethylene and α-olefin is preferable. The silane cross-linked pipe obtained by cross-linking an ethylene homopolymer having a long-chain branched branch in the molecule or a copolymer of ethylene and an α-olefin has insufficient hot internal pressure creep characteristics. Substantially no long chain branching means that ¹³ C-
It means that long chain branching cannot be confirmed by the nuclear magnetic resonance method.

In the present invention, (2) the organic peroxide added to the ethylene homopolymer or the copolymer of ethylene and α-olefin is decomposed into radicals in the extrusion step, and the organic unsaturated silane compound is converted into the ethylene homopolymer. Or ethylene and α
-Graft to a copolymer with olefin. The organic peroxide is 0.005 to 5 with respect to 100 parts by weight of an ethylene homopolymer or a copolymer of ethylene and an α-olefin.
The amount is preferably 0.007 to 1 part by weight, more preferably 0.01 to 0.5 part by weight. If it is less than 0.005 parts by weight, the graft reaction of the organic unsaturated silane compound does not proceed, and if it exceeds 5 parts by weight, the radicals formed in the ethylene polymer due to the organic peroxide are recombined.
Non-uniform cross-linking progresses, and the extrudability of the pipe is significantly reduced. Further, when a large amount of organic peroxide is used, the odor of the organic peroxide is generated during the passage of water through the silane cross-linked pipe.

As the organic peroxide, the already known dicumyl peroxide, 2,5-dimethyl-2,5-di-
(T-butyl-oxy) -hexyne-3,1,3-bis- (t-butyl-oxy-isopropyl) -benzene,
t-Butyl cumyl peroxide, 4,4, -di- (t
-Butylperoxy) valeric acid-butyl ester,
1,1-di- (t-butylperoxy) -3,3,5-
Trimethylcyclohexanexin-3, benzoyl peroxide, dicyclobenzoperoxide, di-t-butyl peroxide, lauroyl peroxide, di-t-butylperoxyisophthalate, a double bond group and a peroxide group in the molecule Examples of such compounds include dicumyl peroxide, which is economical and preferable.

(3) The organic unsaturated silane compound is 0.1 to 10 parts by weight, preferably 0.3 to 5 parts by weight, based on 100 parts by weight of an ethylene homopolymer or a copolymer of ethylene and an α-olefin. Parts by weight, more preferably 0.5 to 4 parts by weight. When the amount is less than 0.1 parts by weight, the silane crosslinking of the silane crosslinked pipe is insufficient, and when the amount is more than 10 parts by weight, a large amount of eye drops and a load increase at the time of extruding the pipe occur, thereby extruding the pipe. The quality becomes poor. Further, the organic unsaturated silane compound is expensive, and it is not economical to use it in a large amount. The organic unsaturated silane compound may be any conventionally known silane that can be crosslinked, for example, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltributoxysilane, allyltrimethoxysilane, vinylmethyldimethoxysilane,
Examples thereof include vinyltris (β-methoxyethoxy) silane. Such an organic unsaturated silane compound reacts with a radical in an ethylene homopolymer generated by the action of an organic peroxide or a copolymer of ethylene and an α-olefin and is grafted on the ethylene polymer.

The silanol condensation catalyst crosslinks the silane compound grafted to the ethylene polymer in the presence of hot water or steam. As the silanol condensation catalyst, already known dibutyltin dilaurate, stannous acetate, stannous caprylate, tin naphthenate, zinc caprylate, iron 2-ethylhexanoate, cobalt naphthenate, tetrabutyl titanate, Mention may be made of ethylamine, dibutylamine, especially dibutyltin dilaurylate, dibutyltin diacetate, dibutyl octate. The method of using these silanol condensation catalysts is not particularly limited.

For example, a silanol condensation catalyst is added to the composition of (1) ethylene polymer (2) organic peroxide (3) organic unsaturated silane compound of the present invention, and the mixture is melt-mixed by an extruder and then pipe-formed. Then, the obtained pipe is cross-linked with silane groups in the presence of warm water or steam, (1) ethylene polymer (2) organic peroxide (3) composition of organic unsaturated silane compound is extruded once to obtain A method of adding a silanol condensation catalyst to the obtained composition to form a pipe, and crosslinking the obtained pipe with a silane group in the presence of hot water or steam, (1) ethylene polymer (2) organic peroxide (3 ) A method of forming a pipe from a composition of an organic unsaturated silane compound and exposing the pipe to the presence of hot water or steam containing a silanol condensation catalyst to crosslink the silane groups.

Particularly when a silanol condensation catalyst is added to a composition of an ethylene polymer, an organic peroxide and an organic unsaturated silane compound, the amount of the silanol condensation catalyst is 0.00 based on 100 parts by weight of the composition.
1 to 10 parts by weight is preferable. If the amount is less than 0.001 parts by weight, it takes a long time to crosslink the silane, while if it exceeds 10 parts by weight, there is a problem that the silanol condensation catalyst is dissolved in water when water is passed through the silane crosslinking pipe. .
In the production of the silane crosslinked pipe, the ethylene polymer may be used in the form of pellets or powder. The organic peroxide, organic unsaturated silane compound, and silanol condensation catalyst may be used alone or as a masterbatch with an ethylene polymer.

The silane cross-linked pipe of the present invention has a gel fraction of 6
It is preferably at least 5%. This gel fraction has a high value when the organosilane compound in the polymer is uniformly grafted and the silane group is uniformly crosslinked by the silanol condensation catalyst. It is empirically known that a silane crosslinked pipe with a high gel fraction has excellent mechanical strength such as short-term and long-term hot internal pressure creep, but in order to obtain a high gel fraction in a conventional ethylene polymer, It is necessary to use a large amount of organic unsaturated silane compound. Moreover, conventionally, even if a high gel fraction is achieved in a silane crosslinked pipe using an ethylene polymer, the hot internal pressure creep property is not satisfactory. On the other hand, with the specific ethylene polymer used in the present invention, a high gel fraction can be obtained even with a small amount of the organic silane compound added, and sufficient mechanical properties can be achieved.

The method for measuring the gel fraction of the silane crosslinked pipe will be described below. The silane cross-linked pipe was cut into 10 g, extracted with a Soxhlet extractor using a xylene solvent for 10 hours, and the residual extraction amount was measured and calculated by the following formula.

[Formula 1]

The ethylene polymer or the copolymer of ethylene and α-olefin used in the present invention is a known phenolic stabilizer, organic phosphite stabilizer, organic thioether stabilizer, metal salt of higher fatty acid, etc. Stabilizer, pigment, weathering agent, dye, nucleating agent, lubricant such as calcium stearate, inorganic filler or reinforcing material such as carbon black, talc, glass fiber, flame retardant, compound added to polyolefin such as neutron blocker The agent can be added within a range that does not impair the object of the present invention. Further, an adsorbent such as activated carbon may be added in order to suppress elution of unreacted organic unsaturated silane compound, silanol condensation catalyst and organic peroxide from the silane cross-linked pipe.

Examples of the phenolic stabilizer include 2,6-di-t-butyl-4-methylphenol, 2,6-dicyclohexyl-4-methylphenol, 2,6-diisopropyl-4-ethylphenol, and 2,6-di-t-amilou. 4-methylphenol, 2,6-di-t-octyl-4-n-propylphenol, 2,6-dicyclohexyl-4-n-octylphenol, 2-isopropyl-4-methyl-6-t-butylphenol, 2-t-butyl-2-ethyl-6-t- Octylphenol, 2
-Isobutyl-4-ethyl-6-t-hexylphenol, 2-cyclohexyl-4-n-butyl-6-isopropylphenol, tetrakis (methylene (3,5-di-t-butyl-4-hydroxy) hydrocinnamate)
Methane, 2,2, -methylenebis (4-methyl-6-t
-Butylphenol), 4,4, -butylidene bis (3
-Methyl-6-t-butylphenol), 4,4, -thiobis (3-methyl-6-t-butylphenol),

2,2-thiobis (4-methyl-6-t)
-Butylphenol), 1,3,5-trimethyl-2,
4,6-tris (3,5-di-t-butyl-4-hydroxyphenyl) benzylbenzene, 1,3,5-tris (2-methyl-4-hydroxy-5-t-butylphenol) methane, tetrakis (methylene (3,5-di-butyl-4-hydroxyphenyl) ) Propionate) methane, β- (3,5-di-t-butyl-4-hydroxylphenol) propionic acid alkyl ester, 2,
2, -Oxamide bis (ethyl-3- (3,5-di-t
-Butyl-4-hydroxyphenyl) propionate,
Tetrakis (methylene (2,4-di-t-butyl-4-hydroxyl) propionate), n-octadecyl-3- (4, -hydroxy-3,5-di-t-butylphenyl) propionate,

2,6-di-t-butyl-p-cresol, 2,4,6-tris (3,5, di-t-butyl-4, -hydroxybenzylthiono 1,3,5-triazine, 2,2, -methylenebis (4-methyl-) 6-t-butylphenol), 4,4, -methylenebis (2,6
-T-butylphenol), 2,2, -methylenebis (6- (1-methylcyclohexyl) -p-cresol), bis (3,5-bis (4-hydroxy-3-t-butylphenyl) butyric acid) glycol ester, 4,4 , -Butylidene bis (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-4-t-butylbenzyl) isocyanurate, 1,3,3
5-tris (3,5-di-t-butyl-4-hydroxybenzyl) -2,4,6-trimethylbenzene, 1,
3,5-tris (3,5-di-t-butyl-4-hydroxybenzyl) isocyanate, 1,3,5-tris ((3,5-di-t-butyl-4-hydroxyphenyl) propionyloxyethyl) isocyanurate,
2-octylthio-4,6-di (4-hydroxy-3,3
Examples thereof include 5-di-t-butyl) phenoxy-1,3,5-triazine and 4,4-thiobis (6-t-butyl-m-cresol).

As the organic phosphite stabilizer, trioctyl phosphite, trilauryl phosphite,
Tridecyl phosphite, octyl diphosphite,
Tris (2,4-di-t-butylphenyl) phosphite, triphenylphosphite, tris (butoxyethyl) phosphite, tris (nonylphenyl) phosphite, distearyl pentaerythritol diphosphite, tetra (tridecyl) -1,1, 3-tris (2-methyl-5-t-butyl-4-hydroxyphenyl) butanediphosphite, tetra (tridecyl) -4,4
-Butylidene bis (3-methyl-6-t-butylphenol) diphosphite, tris (3,5-di-t-butyl-4-hydroxyphenyl) phosphite, tris (mono- or dinonylphenyl) phosphite,

Hydrogenated-4,4-isopropylidenediphenol polyphosphide, bis (octylphenyl)
Bis (4,4-butylidene bis (3-methyl-6-t
-Butylphenol)) 1,6-hexaneol diphosphide, phenyl-4,4, -isopropylidene diphenol pentaerythritol diphosphide, bis (2,4-di-t-butylphenyl) pentaerythritol diphosphide, bis (2,6 -T-butyl-4-methylphenyl) pentaerythritol diphosphide, tri ((4,4, -isopropylidene bis (2-t
-Butylphenol)) phosphide, di (nonylphenyl) pentaerythritol diphosphide, tris (1,3-distearoyloxyisopropyl) phosphite, 4,4, -isopropylidenebis (2-t-butylphenol) di (nonylphenyl) ) Phosphide, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, tetrakis (2,4-di-t-butylphenyl) -4,4, -biphenylenediphosphide and the like.

Examples of the organic thioether type stabilizers include dialkyl thiopropionates such as dilauryloo, dimyristyl, distearyl, and butyl, octyl,
Esters of polyhydric alcohols of alkylthiopropionic acids such as lauryl, stearyl, etc. (eg glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, trishydroxyethyl isocyanurate) (eg pentaerythritol tetralauryl thiopropionate) Is mentioned. More specifically, dilauryl thiopropionate, dimyristyl thiopropionate, distearyl thiodipropionate, lauryl stearyl thiodipropionate, distearyl thiodibutyrate and the like can be mentioned.

Examples of the metal salt of higher fatty acid include alkaline earth metal salts such as magnesium, calcium and barium salts of higher fatty acids such as stearic acid, oleic acid, lauric acid, caprylic acid, arachidic acid, palmitic acid and behenic acid. Cadmium salt, zinc salt, lead salt, sodium salt, potassium salt, lithium salt and the like are used. Magnesium stearate, magnesium laurate, magnesium palmitate, calcium stearate calcium oleate, barium stearate, barium laurate, barium laurate, magnesium, zinc stearate, zinc calcium oleate, zinc stearate, zinc laurate, Examples include lithium stearate, sodium stearate, sodium palmitate, sodium laurate, potassium stearate, potassium laurate, and calcium 12-hydroxystearate.

[0065]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail below with reference to Examples, but these do not limit the scope of the present invention. MI2.16; 190 according to ASTM-D-1238
It is a value measured at a temperature of 2.degree. C. and a load of 2.16 kg. MI21.6 / MI2.16; temperature 190 ° C, load 21.6
It is the value of the melt index (MI21.6) measured in kg, measured at 190 ° C. under a load of 2.16 kg, and divided by the melt index (MI2.16). Molecular weight distribution; measuring device used for measurement is Waters
150-C, ALC / GPC, Sh as column
AT-807S manufactured by odex and TSK-ge manufactured by Tosoh Corporation
It was measured at 140 ° C. by using 1GMH-H6 in series and using trichlorobenzene containing 10 ppm of Irganox 1010 (trade name) as a solvent. A commercially available monodisperse polystyrene was used as a standard substance to prepare a calibration curve.

Η 100 measurement: Rheometric, using ARES manufactured by Scientific Co., was used, and a flat plate having a diameter of 25 mm, a flat plate gap of 3 mm, and an ethylene homopolymer or a copolymer of ethylene and α-olefin were sandwiched between the plates and the temperature was adjusted to 2
The viscosity at a shear rate of 100 rad / s was evaluated at 00 ° C. Gel fraction; 10 g of silane cross-linked pipe was cut, extracted with a Soxhlet extractor for 10 hours using a xylene solvent,
The remaining extraction amount is measured and calculated by the following formula.

[Formula 2] 95 ° C hot internal pressure creep; crack was caused by applying a circumferential stress of 5.5 MPa to a silane crosslinked pipe in warm water of 95 ° C.
The time to leak was evaluated. Tensile properties of pipes: Tensile strength and elongation of silane cross-linked pipes were evaluated according to JIS-K6760. The tensile yield strength of the silane crosslinked pipe is an index for the flexibility evaluation required when the silane crosslinked pipe is used in a sheathing method or the like. Evaluation of odor: The appearance was evaluated using a silane cross-linked pipe, and the odor of water after the silane cross-linked pipe was soaked in warm water at 50 ° C. for 24 hours was evaluated (good, acceptable, not acceptable).

[0067]

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 90
The mixture was stirred at 0 ° C for 30 minutes. Next, 40 ml of a 1 mol / l trihexylaluminum toluene solution was added to this solution, and the mixture was stirred at 90 ° C. for 1 minute. On the other hand, silica P-10 (trade name, manufactured by Fuji Silysia Ltd., Japan) was treated with a nitrogen stream at 500 ° C. for 3 hours, and the treated silica was put in 1.7 l of toluene and stirred. To the silica slurry solution was added the toluene solution of triethylammonium tris (pentafluorophenyl) (4-hydroxyphenyl) borate and trihexylaluminum, and the mixture was stirred for 90 hours for 3 hours.
Stir at ℃.

Then, 206 ml of a 1 mol / l trihexylaluminum toluene solution was added, and the mixture was further stirred at 90 ° C. for 1 hour. Then, the supernatant was decanted 5 times using toluene at 90 ° C. to remove excess trihexylaluminum. 0.218 mol / l dark purple titanium (N-1,1-dimethylethyl) dimethyl (1- (1,2,3,4,5, -eta) -2,3
4,5-Tetramethyl-2,4-cyclopentadiene-
1-yl) silanaminate) ((2-) N)-(η4−
1,3-Pentadiene) ISOPARTME (E, USA)
20 ml of xxon chemical) solution was added to the above mixture and 3
After stirring for a time, a green supported catalyst was obtained. Part of the obtained supported catalyst was mixed with 0.8 liters of dehydrated and deoxygenated hexane for 1.5
It was placed in a 1-liter reactor. With the temperature inside the vessel set to 75 ° C., a mixed gas of ethylene, 1-butene and hydrogen (gas composition: 700 g of ethylene, 6 g of 1-butene, 0.5 liter of hydrogen) and total pressure of 8
It was set to kg / cm ² .

Polymerization was carried out for 2 hours while keeping the total pressure at 8 kg / cm ² by replenishing the mixed gas having the above composition to obtain an ethylene copolymer shown in Table 1. The amount of vinyltrimethoxysilane shown in Table 1 in the obtained ethylene copolymer powder,
The amount of dicumyl peroxide was Henschel mixed and extruded using a single screw extruder at an extrusion temperature of 260 ° C. 0.01 parts by weight of dioctyltin dilaurylate and Irganox 1010 per 100 parts by weight of the obtained pellets.
(Product name) 0.4 part by weight is mixed, and a single screw extruder (measured temperature 60-190-210-220-210-210 is again used.
℃, L / D22, compression ratio 3.5,) using nominal diameter 13
Molded pipe. The pipe was infiltrated with hot water at 90 ° C. for 9 hours to be crosslinked, to form the silane crosslinked pipe of the present invention. The obtained silane crosslinked pipe had a high gel fraction and had excellent mechanical properties. Moreover, the silane cross-linked pipe had no problem in appearance and odor.

[0070]

Examples 2 to 4 Example 2 shown in Table 1 was carried out according to the production method of Example 1, except that the butene-1 amount and the hydrogen amount were changed.
Three and four ethylene polymers were produced. Using the obtained ethylene polymer, the same operation as in Example 1 was carried out to obtain a silane crosslinked pipe. The obtained silane crosslinked pipe had a high gel fraction and had excellent mechanical strength. Further, the silane cross-linked pipe had no problem in appearance and odor.

[0071]

[Comparative Examples 1 to 7] Comparative Examples 1 to 1 shown in Table 1 according to the production method of Example 1 except that the butene-1 amount and the hydrogen amount were changed.
An ethylene polymer of 7 was produced. A silane crosslinked pipe was molded using the obtained ethylene polymer. In Comparative Example 1, the density of the ethylene polymer is low, the organosilane graft reaction proceeds nonuniformly, and the mechanical properties and appearance of the silane crosslinked pipe are poor. In Comparative Example 2, the ethylene polymer has a high melt flow index and the mechanical strength of the silane crosslinked pipe is poor. In Comparative Example 3, the ethylene polymer had a low melt flow index and pipe extrusion could not be performed.
In Comparative Example 4, the amount of vinylethoxysilane was insufficient,
The graft reaction is insufficient and the gel fraction is low. Therefore, the mechanical properties of the silane crosslinked pipe are poor.

Comparative Example 5 contains a large amount of vinylethoxysilane,
The appearance of the silane cross-linked pipe is poor, and a large amount of unreacted vinylethoxysilane remains in the silane cross-linked pipe, causing odor in water. Comparative Example 6 has a large amount of dicumyl peroxide, and during extrusion of the composition of the ethylene polymer, the organic peroxide, and the organic unsaturated silane compound, the resin temperature rises to 370 ° C. due to internal heat generation, and the extrusion load increases. Therefore, the composition could not be produced. In Comparative Example 7, since dicumyl peroxide was insufficient and the graft reaction of the organic unsaturated silane compound did not proceed, the gel fraction was low and the mechanical properties were insufficient.

[0073]

Comparative Example 8 Ziegler-catalyzed ethylene polymer Using a known Ziegler catalyst prepared from magnesium chloride hexahydrate, 2-ethylhexanol and titanium tetrachloride, the ethylene copolymer of Comparative Example 8 shown in Table 1 was used. The polymer was polymerized. The silane cross-linked pipe of the obtained ethylene copolymer has a low molecular weight and the components having many comonomers inserted are highly silane cross-linked, and the mechanical properties are poor because the silane cross-linking of the high molecular weight component is insufficient. . In addition, a sufficient gel fraction could not be obtained unless a large amount of organic unsaturated silane compound was added.

[0074]

Comparative Example 9 Zirconocene-Catalyzed Ethylene Copolymer Silica (Grande 952, manufactured by Fuji Debuisson Co., Ltd.) 4 in a 200 ml flask that had been thoroughly nitrogen-dried.
g and 40 ml of toluene were added, and the mixture was cooled to -40 ° C.
30 ml of a toluene solution of methylalumoxane (MMAO-3 manufactured by Tosoh Akzo Co., Ltd .: trade name) is added and reacted for 1 hour, then reacted at 0 ° C for 1 hour and further at 80 ° C for 3 hours, and cooled to 20 ° C after completion of the reaction. Then, a silica carrier carrying methylalumoxane was obtained. Next, 2.5 ml / l of a toluene solution of bis (n-butylcyclopentadienyl) zirconium dichloride was converted to 1 μm in terms of zirconium.
ol, and triisobutylaluminum (1.0mo
l / l) 0.12 mmol was added to synthesize the catalyst. The resulting suspension solution was dehydrated and deoxygenated, and together with 0.8 l of hexane, the inside was degassed in vacuum and placed in a 1.5 l reactor which was replaced with nitrogen.

With the temperature inside the container set to 75 ° C., ethylene and 1-
The amount of a mixed gas of butene and hydrogen was adjusted (gas composition: 700 g of ethylene, 1-butene: 6 g, hydrogen: 0.15 l) so that the total pressure was 8 kg / cm ² . Polymerization was carried out for 2 hours while keeping the total pressure at 10 kg / cm ² by replenishing the mixed gas to obtain an ethylene copolymer shown in Table 1. The obtained ethylene polymer was used to form a silane crosslinked pipe. Since the molecular weight distribution was narrower than that of the ethylene copolymer of Example 1, the extrusion load and the resin temperature increased during extrusion molding of the pipe. The gel fraction of the obtained silane crosslinked pipe is high, but the hot internal pressure creep property is insufficient.

[0076]

[Table 1]

[0077]

The silane cross-linked pipe using the specific ethylene homopolymer of the present invention or the copolymer of ethylene and α-olefin has uniform silane cross-linking,
It has an excellent appearance and has no odor during water passage. This silane cross-linked pipe is particularly preferably used for water supply, hot water supply, and heating pipes.

Continuation of front page (51) Int.Cl. ⁷ identification code FI C08K 5/541 C08L 23/08 C08L 23/08 F16L 11/04 F16L 11/04 C08K 5/54 (56) Reference JP-A-10-193468 (JP, A) JP 9-309926 (JP, A) JP 6-65443 (JP, A) JP 9-208637 (JP, A) JP 8-20605 (JP, A) Osaka "Plastic Reader" edited by the editorial committee of the Plastic Research Institute, Municipal Industrial Research Institute (August 15, 1992, Plastic Age Co., Ltd.)

Claims (8)

(57) [Claims] 1. (1) (a) carrier material, (b) organoaluminum compound, (c) titanium compound having cyclic η-bonding anion ligand, and (d) the cyclic η-bonding anion ligand. using a supported catalyst prepared from a complex capable of forming an activator which express catalytic activity by reacting with titanium compounds having obtained, and, having a characteristic from the following (a) (D) Rue 100 parts by weight of a copolymer of ethylene and α-olefin, (A) Melt index (MI2.16) at 190 ° C under a load of 2.16 kg of 0.5 to 10 g / 10 minutes (B) gel permeation chromatography The molecular weight distribution measured at 3.5-5.5 (C) has a density of 0.925 g / cm ³ or more (D) at 200 ° C. and a viscosity (η 100) at a shear rate F of 100 rad / s of 2000 Pa.s. s or less (2) 0.005 to 5 parts by weight of organic peroxide (3) A silane crosslinked pipe obtained by crosslinking 0.110 parts by weight of an organic unsaturated silane compound with a silanol condensation catalyst. . 2. (c) Having a cyclic η-bonding anionic ligand
Is a titanium compound represented by the following general formula (2):
The silane according to claim 1, which is a compound
Cross-linked pipe. [Chemical 1] (In the formula, M is a titania with a formal oxidation number of +2, +3, or +4.
Umm. R ³ is independently hydrogen or hydrocarbon.
Group, silyl group, germyl group, cyano group, halogen,
Are these complex groups, each containing up to 20 non-hydrogen atoms
R ³ which can be held and which are close to each other
Such as drocarbadiyl, siladiyl or germadiyl
It may form a divalent derivative to form a ring. ) 3. A copolymer of ethylene and α-olefin.
Is characterized by being obtained by a slurry polymerization method.
The silane cross-linked pipe according to claim 1 or 2. 4. A melt index (MI21.6) under a load of 21.6 kg at 190 ° C. and a melt index (MI2.16) under a load of 2.16 kg at 190 ° C.
4. An ethylene homopolymer having a ratio of MI21.6 / MI2.16 of 17 to 38, or a copolymer of ethylene and α-olefin is used .
Silane cross-linking pipe as claimed in. 5. The density is 0.930 to 0.944 g / cm.
³ a is ethylene, silane-crosslinked pipe according to any one of claims 1 to 4, characterized in that a copolymer of α- olefins. 6. silane cross pipe according to any one of claims 1 to 5 obtained by crosslinking with 0.001 to 10 parts by weight silanol condensation catalyst relative to 100 parts by weight of the composition of claim 1, wherein . 7. A gel fraction of 65% or more.
6. The silane crosslinked pipe according to any one of 6 . 8. A water supply, hot water supply, silane-crosslinked pipe according to any one of claims 1 to 7, characterized in that used in the heating pipe.