JP6146089B2 - Silanol condensation catalyst and silane cross-linked polyolefin - Google Patents

Description

  The present invention relates to a novel silanol condensation catalyst and a silane-crosslinked polyolefin containing the silanol condensation catalyst. The silane crosslinkable polyolefin containing the silanol condensation catalyst of the present invention is used for electric wire / cable coating materials, pipes, hoses, tubes, various containers, sealing materials, films, sheets and the like.

Silane-crosslinked polyolefin is produced by graft-copolymerizing a silane compound such as vinylalkoxysilane onto polyolefin and exposing it to warm water to cause a crosslinking reaction. The silanol condensation catalyst causes a hydrolysis reaction and a condensation reaction of the silane compound, bonds the molecules of the polymer, and thereby promotes crosslinking.
Conventionally, organotin compounds mainly used as silanol condensation catalysts have safety concerns due to environmental hormone problems, and organic sulfonic acids and their hydrolysis precursors proposed as non-tin condensation catalysts are colored and odorous. There's a problem.

Moreover, as a silanol condensation catalyst, organic zinc compounds such as zinc laurate, zinc octylate, zinc stearate, zinc pt-butylbenzoate, and organic aluminum compounds such as aluminum adipate, aluminum laurate, aluminum octylate, etc. Development has also been made (Patent Document 1, Patent Document 2, etc.).
The organoaluminum compound is advantageous in terms of cross-linking performance because it is not colored compared to other metal compounds, but conventional organoaluminum compounds have not been sufficient in terms of cross-linking performance.

JP 2002-146150 A Special table 2004-526808 gazette

  An object of the present invention is to provide a novel silanol condensation catalyst having excellent crosslinking performance and low environmental load, and a silane-crosslinked polyolefin using the same.

The present inventors have found that a specific organoaluminum compound can be an excellent silanol condensation catalyst capable of achieving the above-mentioned problems, and have completed the present invention.
That is, the gist of the present invention is as follows [1] to [9].
[1] Silanol condensation comprising an aluminum compound represented by the following (1), an aluminum compound represented by the following formula (2), and an organoaluminum compound selected from trialkylcarbonyloxyaluminum catalyst.
Al (OH) _a (R ¹ ) _b (1)
(In the formula, R ¹ represents an alkylcarbonyloxy group substituted with a hydrophilic group, a represents an integer of 0 to 2, and b represents an integer of 1 to 3.)
Al (OH) _c (R ² ) _d (2)
(In the formula, R ² represents an alkylcarbonyloxy group, c represents an integer of 1 to 2, and d represents an integer of 1 to 2)
[2] an organic aluminum compound, acetylacetone aluminum, stearate aluminum tri, characterized in that it is a bis (2-ethylhexanoate NOR g) hydroxy aluminum, one or more compounds selected from aluminum glycinate [1] The silanol condensation catalyst according to 1.
[3] A silanol condensation catalyst-containing polyolefin comprising the silanol condensation catalyst according to [1] or [2] and a polyolefin.
[4] The silanol condensation catalyst-containing polyolefin according to [3], wherein the content of the silanol condensation catalyst is 1000 mass ppm or more and 40001 mass ppm or less with respect to the polyolefin.
[5] A silane-crosslinked polyolefin, wherein the silane-modified polyolefin contains the silanol condensation catalyst according to [1] or [2] or the silanol condensation catalyst-containing polyolefin according to [3] or [4]. .
[6] The silane-crosslinked polyolefin as described in [5], wherein the content of the silanol condensation catalyst is 50 mass ppm or more and 2000 mass ppm or less with respect to the silane-modified polyolefin.
[7] The silane-crosslinked polyolefin according to [5] or [6], further comprising an antioxidant.
[8] The silane-crosslinked polyolefin according to any one of [5] to [7], which is a molded product.
[9] The silane-crosslinked polyolefin according to [8], wherein the molded product is an electric wire / cable coating material, a pipe, a hose, a tube, various containers, a sealing material, a film, or a sheet.

  According to the present invention, it is possible to provide a silanol condensation catalyst that is excellent in crosslinking performance, has little elution into warm water, and has no environmental load, odor, coloring, or the like. The silane crosslinkable polyolefin containing the silanol condensation catalyst of the present invention can be particularly suitably used as a molded product of an electric wire / cable coating material, pipe, hose, tube, various containers, sealing material, film, sheet and the like.

Hereinafter, the present invention will be described in more detail. The present invention is not limited to the embodiments described below, and can be implemented with various modifications within the scope of the gist.
(1) Silanol condensation catalyst The silanol condensation catalyst of the present invention comprises an organoaluminum compound. Examples of the organoaluminum compound include the following compounds.

For example, the following formula (1):
Al (OH) _a (R ¹ ) _b (1)
(Wherein R ¹ represents an alkylcarbonyloxy group substituted with a hydrophilic group, a represents an integer of 0 to 2, and b represents an integer of 1 to 3), Following formula (2):
Al (OH) _c (R ² ) _d (2)
(Wherein R ² represents an alkylcarbonyloxy group, c represents an integer of 1 to 2, and d represents an integer of 1 to 2) or a trialkylcarbonyloxyaluminum represented by Can be mentioned.

Following formula (1):
Al (OH) _a (R ¹ ) _b (1)
(Wherein R ¹ represents an alkylcarbonyloxy group substituted with a hydrophilic group, a represents an integer of 0 to 2, and b represents an integer of 1 to 3), and R 1 represents a hydrophilic group. A substituted alkylcarbonyloxy group is shown. The alkyl group of the alkylcarbonyloxy group is usually a linear, branched or cyclic saturated or unsaturated hydrocarbon group having 1 to 20 carbon atoms, preferably 2 to 10 carbon atoms. Examples of these include methyl, ethyl, propyl, butyl, hexyl, octyl and the like substituted with a hydrophilic group, and among these, methyl, ethyl and the like substituted with a hydrophilic group are preferred.

The substituent of the alkylcarbonyloxy group is usually a hydrophilic group, and examples thereof include a hydroxyl group, a carboxyl group, an amino group, and the like. Among these, a hydroxyl group and an amino group are preferable. The number of hydrophilic groups is preferably 1 to 2. Moreover, what reacts with water and forms the said hydrophilic group is also contained.
a shows the integer of 0-2. b shows the integer of 1-3. Although it is preferable that a hydroxyl group is directly bonded to Al, even if it is absent, it is sufficient that the alkylcarbonyloxy group is substituted with a hydrophilic group.

  Examples of the compound represented by the above formula (1) include tris ((2-hydroxypropionic acid) aluminum (aluminum lactate), aminoacetic acid dihydroxyaluminum (aluminum glycinate), and tris (2,4-pentadionato) aluminum. (III) (aluminum acetylacetonate, acetylacetone aluminum) is preferred, and these compounds have particularly good crosslinking performance.

Following formula (2):
Al (OH) _c (R ² ) _d (2)
In the formula, R ² represents an alkylcarbonyloxy group, c represents an integer of 1 to 2, and d represents an integer of 1 to ² , and R ² represents an alkylcarbonyloxy group. The alkyl group of the alkylcarbonyloxy group is usually a linear, branched or cyclic saturated or unsaturated hydrocarbon group having 1 to 20 carbon atoms, preferably 2 to 10 carbon atoms. Examples of these include methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, n-pentyl, methylpentyl, ethylpentyl and the like.

c shows the integer of 1-2. It is preferable that a hydroxyl group is directly bonded to Al. d shows the integer of 1-2.
As such a compound represented by the above formula (2), bis (2-ethylhexanoato) hydroxyaluminum is preferable. This compound has particularly good crosslinking performance.
Trialkylcarbonyloxyaluminum having an alkyl carbon number of 13 or more, preferably 15 or more, more preferably 17 or more is preferable. The upper limit of the alkyl is not particularly limited, but it may be substantially available, for example, 23. Among these, aluminum tristearate (aluminum stearate tri) is preferable. This compound has particularly good crosslinking performance.

There is no restriction | limiting in particular in content of the silanol condensation catalyst of this invention, What is necessary is just content which can express the function as a silanol condensation catalyst in the content which can become use conditions mentioned later, and the use conditions mentioned later.
As described above, organotin compounds that have been used mainly as conventional silanol condensation catalysts have safety concerns due to environmental hormone problems. Moreover, the organic sulfonic acid proposed as a non-tin condensation catalyst and its hydrolysis precursor (for example, refer patent document 1) have a problem of coloring and odor. In contrast, the silanol condensation catalyst of the present invention has excellent catalytic performance, no environmental hormone problems, no coloring or odor problems, little elution into warm water, and easy handling. Is.

(2) Silanol condensation catalyst-containing polyolefin The silanol condensation catalyst-containing polyolefin of the present invention is characterized by containing the above silanol condensation catalyst and polyolefin. This silanol condensation catalyst-containing polyolefin is used as a master batch of a silanol condensation catalyst when preparing a silane-crosslinked polyolefin described later.

A silanol condensation catalyst-containing polyolefin can be obtained by kneading and granulating a silanol condensation catalyst and a polyolefin. The silanol condensation catalyst-containing polyolefin is usually in the form of granules in the form of granules or pellets, preferably pellets.
Examples of polyolefins that can be used for the silanol condensation catalyst-containing polyolefin include, for example, ethylene homopolymer (polyethylene), α-olefins other than ethylene and ethylene as main components, vinyl esters (for example, vinyl acetate), and unsaturated carboxylic acid esters (for example, And a propylene homopolymer, a copolymer of main component propylene and an α-olefin (including ethylene) other than propylene, and the like. Among these, polyethylene and copolymers of ethylene and α-olefins other than ethylene are particularly preferable. These may be used alone or in combination of two or more in any combination.

The silanol condensation catalyst of the present invention may be used alone or in combination of two or more in any combination. Moreover, you may use together another silanol condensation catalyst as needed.
The content of the silanol condensation catalyst is usually 1000 ppm by mass or more, preferably 2000 ppm by mass or more, more preferably 3000 ppm by mass or more with respect to the polyolefin used for the silanol condensation catalyst-containing polyolefin, and the upper limit is usually 40001 ppm by mass or less. , Preferably it is 30001 mass ppm or less, More preferably, it is 20001 mass ppm or less. If the content is too small, the crosslinking reaction does not proceed sufficiently, and if it is too large, the appearance tends to deteriorate.
If necessary, miscible thermoplastic resins, antioxidants (stabilizers), lubricants, fillers, colorants, foaming agents, and other auxiliary materials can be added to the silanol condensation catalyst-containing polyolefin. These additives may be those commonly used and known per se, and those similar to those described later are used.

(3) Silane-crosslinked polyolefin The silane-crosslinked polyolefin of the present invention is characterized in that the silane-modified polyolefin contains the above-mentioned silanol condensation catalyst or silanol condensation catalyst-containing polyolefin. Here, the silane-crosslinked polyolefin includes a molded product. In addition, the silane-modified polyolefin includes those prepared by performing a silanol condensation catalyst simultaneously with the silane modification (grafting reaction) of the polyolefin. That is, the silane-crosslinked polyolefin of the present invention includes all of the silane-crosslinked polyolefin containing the silanol condensation catalyst of the present invention regardless of its production method or molding state. Furthermore, what contains additives, such as antioxidant, is also included in the silane crosslinked polyolefin of this invention.
This will be described in more detail below.

(A) Silane-modified polyolefin Examples of the polyolefin in the silane-modified polyolefin used in the present invention include ethylene homopolymer (polyethylene), α-olefin other than ethylene and ethylene as main components, vinyl esters (for example, vinyl acetate, etc.) Examples thereof include a copolymer with a saturated carboxylic acid ester (for example, ethyl acrylate), a propylene homopolymer, a copolymer of propylene as a main component and an α-olefin (including ethylene) other than propylene. Among these, polyethylene and copolymers of ethylene and α-olefins other than ethylene are particularly preferable. These may be used alone or in combination of two or more in any combination.

  The silane-modified polyolefin is obtained by, for example, copolymerizing the above polyolefin with an olefinically unsaturated silane compound having a hydrolyzable organic group in a molding processing machine such as an extruder in the presence of a radical generator. can get. In this reaction, the unsaturated silane compound is grafted to the polyolefin so that it becomes a cross-linking point between the polyolefins as the base. The obtained silane-modified polyolefin is sometimes referred to as “polyolefin grafted with a silane compound”.

Here, the olefinically unsaturated silane compound having a hydrolyzable organic group is represented by the following formula (3):
RSiR ′ _n Y _3-n (3)
(In the formula, R represents a monovalent olefinically unsaturated hydrocarbon group, Y represents a hydrolyzable organic group, and R ′ is the same as a monovalent hydrocarbon group other than aliphatic unsaturated hydrocarbon or Y. And n represents 0, 1 or 2.)
The silane compound represented by these.

In the formula (2), R is preferably a vinyl group, allyl group, isopropenyl group, butenyl group, R ′ is preferably a methyl group, ethyl group, propyl group, decyl group, phenyl group or the like, Y is a methoxy group, An ethoxy group, formyloxy group, acetoxy group, propionoxy group, alkyl or arylamino group is preferred.
Moreover, as a preferable silane compound, for example, the following formula (4)
CH ₂ = CHSi (OA) ₃ (4)
(In the formula, A represents a monovalent hydrocarbon group having 1 to 8 carbon atoms.)
The compound represented by these is mentioned.

More specifically, for example, represented by vinyltrimethoxysilane, _{vinyltriethoxysilane, CH 2 = C (CH 3} ) COOC 3 H 6 Si (OA) 3 ( where, A is as defined above.) Examples thereof include γ-methacryloyloxypropyltrimethoxysilane, γ-methacryloyloxypropyltriethoxysilane, and the like. Among these, vinyltrimethoxysilane, vinyltriethoxysilane, and γ-methacryloyloxypropyltriethoxysilane are preferable.

These may be used alone or in combination of two or more in any combination.
The addition amount of these compounds is usually 0.01% by mass or more, preferably 0.1% by mass or more, more preferably 0.7% by mass or more, based on the total mass of the silane-modified polyolefin. Is usually 15% by mass or less, preferably 10% by mass or less, more preferably 7% by mass or less, and further preferably 4% by mass or less. If the addition amount is too small, sufficient grafting tends to be difficult, and if it is too much, molding tends to be poor and it is not economical. This added amount has the same meaning as the unit derived from the silane compound in the silane-modified polyolefin.

  Examples of the radical generator used include various organic peroxides and peresters having a strong polymerization initiating action, such as dicumyl peroxide, α, α'-bis (t-butylperoxydiisopropyl) benzene, di-t. -Butyl peroxide, t-butylcumyl peroxide, di-benzoyl peroxide, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexane, t-butylperoxypivalate, di-t- Examples include butyl peroxide and t-butyl peroxy-2-ethylhexanoate. Of these, dicumyl peroxide and benzoyl peroxide are preferred. These radical generators may be used alone or in combination of two or more in any combination.

  The amount of the radical generator used is usually 0.01% by mass or more, preferably 0.02% by mass or more, more preferably 0.03% by mass or more, based on the total mass of the silane-modified polyolefin. The upper limit is usually 0.5% by mass or less, preferably 0.4% by mass or less, and more preferably 0.2% by mass or less. If the amount used is too small, a sufficient grafting reaction tends to be difficult, and if it is too large, the extrusion processability is lowered and the molding surface tends to be deteriorated.

The silane-modified polyolefin is a normal random copolymer of the silane compound with, for example, ethylene, and is a copolymer obtained by radical copolymerization under normal high pressure polymerization conditions in low density polyethylene. There may be. In the case of this radical copolymerization, vinyl acetate, acrylic acid, methacrylic acid and esters thereof may be further copolymerized. The content of units derived from the silane compound in these copolymers is the same as described above.

  Of the silane-modified polyolefins, polyolefins grafted with silane compounds are preferred. In addition, the silane-modified polyolefin used in the present invention may be a blend of two or more silane-modified polyolefins or a blend of silane-modified polyolefin and polyolefin if the content of units derived from the silane compound is appropriate. Used.

(B) Content of silanol condensation catalyst The content of the silanol condensation catalyst in the silane-crosslinked polyolefin is usually 50 ppm by mass or more, preferably 100 ppm by mass or more, more preferably 200 ppm by mass or more with respect to the polyolefin. Usually, it is 2000 mass ppm or less, preferably 1500 mass ppm or less, more preferably 1000 mass ppm or less. If the content is too small, the crosslinking reaction does not proceed sufficiently, and if it is too large, the appearance tends to deteriorate. Here, the content of the silanol condensation catalyst is the content of the aluminum compound represented by the formula (1) or the formula (2).

  The silanol condensation catalyst may be contained by dry blending or may be contained as a master batch, and the addition method is not particularly limited. Preferably, the silanol condensation catalyst of the present invention is contained as a master batch. This has the advantageous effect of uniform dispersion of the catalyst during molding and good handling. Moreover, you may use together silanol condensation catalyst other than the silanol condensation catalyst of this invention as needed.

(C) Additives The silane-crosslinked polyolefin of the present invention may contain miscible thermoplastic resins, antioxidants, lubricants, fillers, colorants, foaming agents, and other auxiliary materials as necessary. Can do. These additives may be those commonly used and known per se.
Among these, it is preferable to contain an antioxidant particularly for improving the heat-resistant deterioration characteristics. Examples of the antioxidant that can be used include 2,2-thio-diethylenebis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], pentaerythrityl-tetrakis [3- (3 , 5-di-t-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, 2,4-bis- (n-octylthio) -6- (4-hydroxy-3,5-di-t-butylanilino) -1,3,5-triazine, bis [2-methyl-4- {3-n-alkyl (C12 or C14) thiopropionyloxy} -5-tert-butylphenyl] sulfide, 4,4'-thiobis (3-methyl-6-tert-butylphenol), dilauryl thiodipropionate, dimyri Chi thiodipropionate, distearyl thiodipropionate, ditridecyl thiodipropionate, tetrakis (methylene-dodecyl thiodipropionate) methane, and the like.

These antioxidants may be used alone or in combination of two or more in any combination.
The additive content of the antioxidant per 100 parts by mass with respect to the silane-crosslinked polyolefin, the lower limit is usually 10 mass ppm or more, preferably 50 mass ppm or more, more preferably 100 mass ppm or more, and the upper limit is usually 20001 mass. ppm or less, preferably 15000 mass ppm or less, more preferably 13000 mass ppm or less. If the amount added is too small, the improvement in heat-resistant deterioration characteristics is not sufficient, and if it is too large, the appearance may deteriorate due to precipitation on the surface of the molded product.

Additives such as antioxidants may be in the form of a dry blend with respect to the polyolefin, or a master batch in which these antioxidants are mixed in the polyolefin in a high concentration may be added. Further, it can be dissolved in a silane compound and mixed with polyolefin in a molding machine such as an extruder together with the addition of the silane compound.
(D) Preparation of Silane Crosslinked Polyolefin The silane crosslinked polyolefin can be prepared by adding a silanol condensation catalyst and, if necessary, an additive to the silane modified polyolefin.

Specific examples of the method for incorporating the silanol condensation catalyst into the silane-modified polyolefin include a method in which the silanol condensation catalyst is dissolved or dispersed in an organic solvent or the like, and this is impregnated or contacted with the silane-modified polyolefin. Although the organic solvent in this case is not limited, For example, toluene, xylene, acetone, etc. are mentioned.
Other methods for incorporating the silanol condensation catalyst into the silane-modified polyolefin include a method of melt-kneading the silane-modified polyolefin and the silanol condensation catalyst, or a silanol condensation catalyst previously contained in a resin different from the silane-modified polyolefin. And a method of melt-kneading the resin and silane-modified polyolefin. Although the apparatus and conditions at the time of melt-kneading are not specifically limited here, the apparatus and conditions which can be used when performing said graft modification by melt-kneading are applicable similarly.

  In the present invention, the preparation of a silane-crosslinked polyolefin is introduced into a polyolefin in a molding machine such as an extruder together with a silane compound and a radical generator, a silanol condensation catalyst, and an additive such as an antioxidant as required. At the same time as the silane modification (grafting reaction) of the polyolefin, a silane crosslinkable polyolefin can be prepared and subsequently formed into a molded product according to the application.

(E) Molded product The silane-crosslinked polyolefin is usually subjected to practical use as a molded product after being molded according to the use and then crosslinked with moisture. As described above, the molding may be performed using an appropriate molding machine such as an extruder.
The crosslinking method is not particularly limited, but for example, a method of immersing the molded product in a constant temperature water bath, a method of leaving (immersing) in a steam, or a method of leaving under humidification is preferable. The lower limit of the temperature is usually 10 ° C or higher, preferably 40 ° C or higher, more preferably 60 ° C or higher, and the upper limit is usually 130 ° C or lower, preferably 120 ° C or lower, more preferably 110 ° C or lower. The lower limit of the humidity is usually 30% RH or more, preferably 40% RH or more, more preferably 50% RH or more, and the lower limit is usually 100% RH or less.

  The gel fraction of the silane-crosslinked polyolefin in the present invention is usually 30% by mass or more, preferably 40% by mass or more, more preferably 50% by mass or more. When the gel fraction of the silane-crosslinked polyolefin is within the above range, good heat resistance can be obtained. The upper limit of the gel fraction of the silane-crosslinked polyolefin is not particularly limited, and may be complete crosslinking (gel fraction 100% by mass). In addition, the value of the said gel fraction is a thing after the bridge | crosslinking by a water | moisture content. The silane-crosslinked polyolefin of the present invention includes those having a gel fraction of less than 50%.

Here, the gel fraction represents the insoluble matter when extracted with boiling xylene using a Soxhlet extractor for 10 hours as a percentage of the mass before extraction.
The silane-crosslinked polyolefin of the present invention can be particularly suitably used as a molded product of an electric wire / cable coating material, a pipe, a hose, a tube, various containers, a sealing material, a film, a sheet, and the like.

Molded articles for these uses can be produced by a method known per se as described above, but the following (i)
The method (ii) is preferred.
(I) A master batch containing a silanol condensation catalyst at a high concentration is prepared, and this is fed together with a silane-modified polyolefin to an extruder and extruded (two-shot method).
(Ii) An additive containing a silanol condensation catalyst and a radical generator is supplied to the polyolefin in the extruder, whereby the graft reaction of the silane compound to the polyolefin and the extrusion molding are simultaneously performed in one extruder (one-shot method). .

In addition, as a method of making the silanol condensation catalyst act on polyolefin, it is possible to infiltrate from the surface of the molded polyolefin other than the method of kneading the silanol catalyst into the polyolefin as described above.
A molded product suitable for a desired use can be obtained by crosslinking with moisture after molding as described above.

  Hereinafter, the present invention will be described more specifically with reference to experimental examples (Examples, Comparative Examples, Reference Examples). In addition, the values of various production conditions and evaluation results in the following examples have meanings as preferable values of the upper limit or the lower limit in the embodiment of the present invention, and the preferable range is the above-described upper limit or lower limit value. It may be a range defined by a combination of values of the following examples or values of the examples.

[Examples 1-4, Comparative Examples 1-2]
Polyolefin resin (LD400, manufactured by Nippon Polyethylene), silanol condensation catalyst (acetylacetone aluminum; manufactured by Sigma Aldrich, aluminum lactate; manufactured by Kishida Chemical Co., Ltd., bis (2-ethylhexanoato) hydroxyaluminum; manufactured by Tokyo Chemical Industry Co., Ltd., aluminum glycy Naruto: Tokyo Chemical Industry Co., Ltd., Tris stearic acid Al; Kishida Chemical Co., Ltd., Aluminum Laurate; Kishida Chemical Co., Ltd.), Antioxidant-1 (RA1010, manufactured by BASF), Antioxidant-2 (MD1024, BASF) ), Antioxidant-3 (Sumilyzer WXRC, manufactured by Sumitomo Chemical Co., Ltd.), and lubricant-1 (Viton Free Flow SCPL100, manufactured by DuPont) at the ratio shown in Table 1 at a set temperature of 180 mm using a 30 mmφ twin-screw kneader. Strands kneaded and extruded at ℃ are pelletized with a pelletizer A silanol condensation catalyst master batch was prepared.

  A mixture of 5 parts by mass of the obtained silanol condensation catalyst masterbatch with 100 parts by mass of silane-modified polyolefin (Linkron XCF800N, manufactured by Mitsubishi Chemical Corporation) was extruded at a temperature of 210 ° C. with a 20 mmφ extruder and extruded with a thickness of 1 mm. Created a sheet. The obtained extruded sheet was immersed in 95 ° C. steam for 168 hours to carry out a crosslinking treatment to obtain a silane-crosslinked polyolefin. The gel fraction was measured using the extruded sheet of the obtained silane-crosslinked polyolefin. These results are shown in Table 1.

  In addition, the compounding ratio in a table | surface is a weight part. The viscosity is a value measured at 25 ° C. using an E-type viscometer. The gel fraction was obtained by subjecting a sheet of silane-crosslinked polyolefin (thickness 1 mm) to Soxhlet extraction for 10 hours in boiling xylene at 144 ° C., and then measuring the mass after drying the undissolved resin. It is a value calculated as a ratio (%) to the mass.

As is clear from the value of the gel fraction, each of Examples 1 to 4 shows a better gel fraction than Comparative Example 1, and it is recognized that it has a low elution property with respect to water. This is an excellent silanol condensation catalyst that can be used in place of a known silanol condensation catalyst and has no low elution and no environmental hormone problem, and its usefulness is great.

Claims (9)

A silanol condensation catalyst comprising an aluminum compound represented by the following (1), an aluminum compound represented by the following formula (2), and an organoaluminum compound selected from trialkylcarbonyloxyaluminum .
Al (OH) _a (R ¹ ) _b (1)
(In the formula, R ¹ represents an alkylcarbonyloxy group substituted with a hydrophilic group, a represents an integer of 0 to 2, and b represents an integer of 1 to 3.)
Al (OH) _c (R ² ) _d (2)
(In the formula, R ² represents an alkylcarbonyloxy group, c represents an integer of 1 to 2, and d represents an integer of 1 to 2) The organic aluminum compound, acetylacetone aluminum, stearate aluminum tri, bis (2-ethylhexanoate NOR g) hydroxy aluminum, according to claim 1, characterized in that one or more compounds selected from aluminum glycinate Silanol condensation catalyst.   3. A silanol condensation catalyst-containing polyolefin comprising the silanol condensation catalyst according to claim 1 or 2 and a polyolefin.   The silanol condensation catalyst-containing polyolefin according to claim 3, wherein the content of the silanol condensation catalyst is 1000 mass ppm or more and 40000 mass ppm or less with respect to the polyolefin.   A silane-crosslinked polyolefin, wherein the silane-modified polyolefin contains the silanol condensation catalyst according to claim 1 or 2 or the silanol condensation catalyst-containing polyolefin according to claim 3 or 4.   The silane-crosslinked polyolefin according to claim 5, wherein the content of the silanol condensation catalyst is 50 mass ppm or more and 2000 mass ppm or less with respect to the silane-modified polyolefin.   Furthermore, antioxidant is contained, The silane crosslinked polyolefin of Claim 5 or 6 characterized by the above-mentioned.   The silane-crosslinked polyolefin according to any one of claims 5 to 7, which is a molded product.   The silane-crosslinked polyolefin according to claim 8, wherein the molded product is an electric wire / cable coating material, a pipe, a hose, a tube, various containers, a sealing material, a film, or a sheet.