JP2019116581A - Catalyst composition for silane crosslink, silane crosslinkable resin composition and wiring material - Google Patents

Abstract

To provide a catalyst composition for silane crosslink capable of being prepared by suppressing foam even when a benzimidazole-based antioxidant, and capable of adding excellent heat resistance, aging resistance and appearance to a crosslinked body of a silane graft resin by using for crosslink of a silane graft resin, and a silane crosslinkable resin composition and a wiring material using the same.SOLUTION: There is provided a catalyst composition for silane crosslink used for crosslink of a silane graft resin by grafting reaction of a silane coupling agent having a hydrolyzable silyl group, containing 100 pts.mass of a carrier resin containing a polyolefin resin, 15 to 50 pts.mass of a benzimidazole-based antioxidant, 25 pts.mass or less of hydrazine-based metal inactivation agent, and 0.05 to 5 pts.mass of a silanol condensation catalyst and having melt flow rate at 190°C and 2.16 kg of 0.1 to 15 g/10 min., and a silane crosslinkable resin composition and a wiring material using the same.SELECTED DRAWING: None

Description

  The present invention relates to a silane crosslinking catalyst composition, a silane crosslinking resin composition, and a wiring material.

A wiring material such as an insulated wire, a tube, a cable, a cord, an optical fiber core wire or an optical fiber cord (optical fiber cable) has a covering layer made of, for example, a polyolefin resin. By crosslinking the polyolefin resin forming the coating layer, the heat resistance of the coating layer can be improved.
As a method of crosslinking a polyolefin resin, a silane crosslinking method is known which has an advantage such as not requiring special equipment. In the silane crosslinking method of a polyolefin resin, generally, first, a silane obtained by grafting a silane coupling agent having a hydrolyzable silyl group and an unsaturated group to a polyolefin resin in the presence of an organic peroxide. A grafted polyolefin resin is prepared. The hydrolyzable silyl group is then condensed by contacting the resulting silane-grafted polyolefin resin with water in the presence of a silanol condensation catalyst. In this way, the polyolefin resin can be silane crosslinked. As an example to which the silane crosslinking method is applied, for example, Patent Document 1 discloses an inorganic filler surface-treated with a silane coupling agent to a resin component formed by mixing a polyolefin resin and a maleic anhydride resin, a silane coupling agent, an organic peroxide A method has been proposed in which the oxide and the crosslinking catalyst are sufficiently melt-kneaded in a kneader and then molded in a single screw extruder.

JP 2001-101928 A

The wiring material is required to have characteristics according to the application. For example, wiring materials used for heat-resistant parts of vehicles such as automobiles can maintain their characteristics not only in heat resistance that is resistant to deformation even under high temperatures, but also in continuous or intermittent high temperature environments ( High aging resistance is required to withstand long-term use.
In general, high aging resistance can be achieved by forming the coating layer of the wiring material with a crosslinked product of a resin composition containing a high content of an antioxidant.

By the way, in the above-mentioned silane crosslinking method, there is a method using a silane graft resin and a catalyst composition for silane crosslinking (catalyst master batch) containing a silanol condensation catalyst.
When a compounding amount of anti-aging agent such as benzimidazole-based anti-aging agent, hydrazine-based heavy metal deactivator, etc. is particularly increased and applied to this silane cross-linking method, the polyolefin resin can be produced by the usual method (electron beam cross-linking or It has been found that a problem which does not exist in the method of crosslinking the resin by chemical crosslinking using an oxide, etc. is manifested. When an antiaging agent is used in the silane crosslinking method, it is contained in a catalyst master batch (also referred to as catalyst MB) in that the dispersibility of the antiaging agent is enhanced and the silane grafting reaction is not inhibited. However, when using a benzimidazole-based anti-aging agent and further a hydrazine-based heavy metal deactivator when preparing a catalyst masterbatch containing an anti-aging agent, melt mixing with the carrier resin used for preparing the catalyst master batch At the same time, gas is generated, and the gas remains in the obtained catalyst master batch to form bubbles (voids) (which is porous (sponge-like)). As a result, bubbles also remain in the cross-linked product obtained by cross-linking the silane graft resin using this catalyst master batch, causing appearance defects. Moreover, when the content of the antiaging agent is increased, the above-mentioned problem of foaming becomes significant. Further, if the cross-linked product of the silane graft resin is subjected to secondary processing, such a cross-linked product may be foamed at high temperatures to impair the required properties of the product.

  The present invention solves the above-mentioned problems, and it can be prepared by suppressing foaming even by using a benzimidazole-based anti-aging agent and further a hydrazine-based heavy metal deactivator, and furthermore, a silane using a silane graft resin It is an object of the present invention to provide a silane crosslinking catalyst composition capable of imparting excellent heat resistance, aging resistance and appearance to a crosslinked product of a silane graft resin obtained by using the crosslinking method. In addition, the present invention is a silane crosslinkable resin composition exhibiting excellent formability, which can form a crosslinked product of a silane cross-linked resin while suppressing appearance defects and bumps by using the catalyst composition for silane cross-linking. It is an object of the present invention to provide a wiring material which has excellent heat resistance, aging resistance and appearance using a silane crosslinkable resin composition and which is difficult to foam even in secondary processing.

  The present inventors have used a carrier resin containing a polyolefin resin in a catalyst composition for silane crosslinking that promotes silanol condensation (silane crosslinking) of a silane graft resin, and the carrier resin comprises a silanol condensation catalyst, benzimidazole based aging Each of the inhibitors, furthermore, hydrazine heavy metal deactivator (also referred to as hydrazine antidegradant) is compounded in a specific amount, and the melt flow rate (flowability) of the resulting silane crosslinking catalyst composition is set. As a result, foaming at the time of preparation as described above can be suppressed, and a silane crosslinkable resin composition using this catalyst composition for silane crosslinking exhibits excellent moldability, and further, for this silane crosslinking. The wiring material using the catalyst composition exhibits excellent heat resistance, aging resistance and appearance, and it has been found that foaming during secondary processing can be suppressed. It was. Based on this finding, the present inventors have further studied and made the present invention.

That is, the object of the present invention is achieved by the following means.
[1]
What is claimed is: 1. A catalyst composition for silane crosslinking, which is used for crosslinking of a silane graft resin grafted with a silane coupling agent having a hydrolyzable silyl group,
Containing 15 to 50 parts by mass of benzimidazole based antioxidant, 25 parts by mass or less of hydrazine based heavy metal deactivator, and 0.05 to 5 parts by mass of silanol condensation catalyst with respect to 100 parts by mass of carrier resin containing polyolefin resin And a catalyst composition for silane crosslinking having a melt flow rate of 0.1 to 15 g / 10 min at 190 ° C. and 2.16 kg.
[2]
The catalyst composition for silane crosslinking according to [1], which contains 30 parts by mass or less of a phenolic antioxidant.
[3]
The catalyst composition for silane crosslinking as described in [1] or [2] whose melt flow rate in said 190 degreeC and 2.16 kg is 0.5-10 g / 10min.
[4]
The catalyst composition for silane crosslinking according to any one of [1] to [3], wherein the carrier resin contains 20% by mass or more of a styrene-based elastomer.
[5]
It is a molten mixture of the catalyst composition for silane crosslinking according to any one of [1] to [4] and a silane graft resin composition containing a base resin, and the base resin is a hydrolyzable silyl group. The silane crosslinking resin composition containing the silane graft resin which the silane coupling agent which has graft-grafted.
[6]
The silane crosslinking resin composition as described in [5] in which the said base resin contains a styrene-type elastomer 10 mass% or more.
[7]
The silane crosslinking resin composition as described in [5] or [6] which contains 10-400 mass parts of inorganic fillers with respect to a total of 100 mass parts of the carrier resin of the said catalyst composition for silane crosslinking, and the said base resin. .
[8]
Wiring material which has a coating layer which consists of hardened | cured material of the silane crosslinking resin composition as described in any one of [5]-[7].
[9]
The wiring material according to [8], which is a heat-resistant wire or cable.

  The numerical range represented using "-" in this specification means the range which includes the numerical value described before and after "-" as a lower limit and an upper limit.

  The present invention can be prepared by suppressing foaming even if it contains a benzimidazole-based anti-aging agent and further a hydrazine-based heavy metal deactivator, and furthermore, it can be used as a silane by being used for crosslinking a silane graft resin. It is possible to provide a silane crosslinking catalyst composition capable of imparting excellent heat resistance, aging resistance and appearance to a crosslinked product of a graft resin. In addition, the present invention is a silane crosslinkable resin composition exhibiting excellent formability, which can form a crosslinked product of a silane cross-linked resin while suppressing appearance defects and bumps by using the catalyst composition for silane cross-linking. Can provide Furthermore, the present invention can provide a wiring material which has excellent heat resistance, aging resistance and appearance using a silane crosslinkable resin composition and is difficult to foam even in secondary processing.

[Catalyst composition for silane crosslinking]
The catalyst composition for silane crosslinking of the present invention comprises a carrier resin, a benzimidazole antioxidant, a hydrazine heavy metal deactivator, and a silanol condensation catalyst in a specific mass ratio, and has a melt flow rate in a specific range. .
The silane crosslinking catalyst composition can be prepared by suppressing foaming due to gas or the like generated at the time of preparation (during melt mixing).

The catalyst composition for silane crosslinking of the present invention is used in a silane crosslinking method in combination with a silane graft resin to which a silane coupling agent having a hydrolyzable silyl group is grafted.
In the present invention, to use the catalyst composition for silane crosslinking and the silane graft resin in combination may be used as long as the catalyst composition for silane crosslinking and the silane graft resin can be used in combination, and other components are further used in combination Also includes. That is, in addition to the embodiment in which the silane crosslinking catalyst composition and the silane graft resin are used in combination, the embodiment in which the silane crosslinking catalyst composition and the silane graft resin composition are used in combination is included.
Moreover, using the catalyst composition for silane crosslinking in the silane crosslinking method means using in the method of silane crosslinking silane graft resin. That is, in addition to the embodiment used to crosslink the silane graft resin (to form a crosslinked product of the silane graft resin), the embodiment used to cure the silane graft resin composition (to form a cured product of the silane crosslinkable resin composition) Include.

When the silane crosslinking resin composition of the present invention is used in combination with a silane graft resin, foaming can be suppressed when preparing (melt and mixing) the silane crosslinkable resin composition. In addition, it is possible to obtain a silane crosslinkable resin composition having excellent formability such that appearance defects and formation of bumps are suppressed at the time of molding. Furthermore, when used in a silane crosslinking method in combination with a silane graft resin, a foamed product is suppressed, and a crosslinked product of a silane graft resin having excellent heat resistance, aging resistance, and appearance (silane crosslinkable resin composition The cured product of By utilizing this characteristic, it is possible to manufacture a wiring material provided with a coating layer containing a cross-linked body of a silane graft resin having excellent characteristics.
In the present invention, the cured product of the silane crosslinkable resin composition of the present invention (silanol condensation cured product obtained by forming the silane crosslinkable resin composition of the present invention after forming the silane crosslinkable resin) is referred to as a silane crosslinked resin molded article is there.

  Each component of the silane crosslinking catalyst composition of the present invention will be described.

<Carrier resin>
The carrier resin contains a polyolefin resin. The carrier resin may further contain a mineral oil.

-Polyolefin resin-
The polyolefin resin is not particularly limited as long as it is a resin comprising a polymer obtained by homopolymerization or copolymerization of a compound having an ethylenically unsaturated bond, and known resins conventionally used in resin compositions Can be used. The polyolefin resin is preferably a resin which is mixed (compatible) with a silane graft resin described later.
Examples of resin components included in the polyolefin resin include polyethylene resin, polypropylene resin, ethylene-α-olefin copolymer resin, polyolefin copolymer resin having an acid copolymer component or an acid ester copolymer component, and And resins such as rubber and elastomers. As a rubber or an elastomer, ethylene-alpha-olefin copolymer rubber, a styrene system elastomer, ethylene acrylic rubber etc. are mentioned, for example.
In the present invention, the polyolefin resin or the resin component may be used alone or in combination of two or more.

(Polyethylene resin)
The polyethylene resin may be a polymer resin containing an ethylene component, and a homopolymer consisting only of ethylene, a copolymer of ethylene and an α-olefin (preferably 5 mol% or less) (corresponding to polypropylene) And resins composed of a copolymer of ethylene and a non-olefin (preferably 1 mol% or less) having only carbon, oxygen and hydrogen atoms as functional groups. In addition, the above-mentioned alpha-olefylene and the non-olefin are used without being restrict | limited in particular the well-known thing conventionally used as a copolymerization component of polyethylene.
The polyethylene resin that can be used in the present invention is high density polyethylene (HDPE), low density polyethylene (LDPE), ultra high molecular weight polyethylene (UHMW-PE), linear low density polyethylene (LLDPE) or ultra low density polyethylene (VLDPE) Can be mentioned. Among them, high density polyethylene, low density polyethylene, and linear low density polyethylene are preferable, and linear low density polyethylene or low density polyethylene is more preferable. The polyethylene resin may be used alone or in combination of two or more.

  Melt flow rate of polyethylene resin (hereinafter sometimes referred to as MFR. In the present invention, unless otherwise specified, MFR is a value measured at 190 ° C. under a load of 2.16 kg according to JIS K 7210. 0.05 to 10 g / 10 min is preferable, and 0.5 to 5.0 g / 10 min is more preferable. By setting the melt flow rate to 0.05 to 10 g / 10 min, it is possible to suppress foaming due to a gas or the like generated from a mixture with a benzimidazole based antioxidant, and to obtain a silane crosslinked resin molded article having an excellent appearance as well. .

(Polypropylene resin)
The polypropylene resin may be a polymer containing a propylene component as a main component, and a resin such as a homopolymer of propylene (homopolypropylene resin), an ethylene-propylene random copolymer, an ethylene-propylene block copolymer, etc. is used can do.
The ethylene-propylene random copolymer refers to one having an ethylene component content of about 1 to 10% by mass, and means an ethylene component randomly incorporated in a propylene chain. In addition, the ethylene-propylene block copolymer refers to one having an ethylene or ethylene-propylene rubber (EPR) component content of about 5 to 20% by mass, and the ethylene or EPR component is independently present in the propylene component. Mean a sea-island structure. Particularly preferable as a polypropylene resin is an ethylene-propylene random copolymer resin in terms of appearance. The ethylene component content is a value measured in accordance with the method described in ASTM D3900.

  The melt flow rate of a polypropylene resin (a value measured under the conditions of a temperature of 230 ° C. and a weight of 2.16 kg according to JIS K 7210) is preferably 0.05 to 25 g / 10 min, and more preferably 0.1 to 20 g / min. 10 g / 10 min is more preferable. By setting the melt flow rate to 0.05 to 25 g / 10 min, it is possible to suppress foaming due to a gas or the like generated from a mixture with a benzimidazole based antioxidant, and to obtain a silane cross-linked resin molded article having an excellent appearance as well. . In addition, the heat distortion characteristics may be improved.

(Ethylene-α-olefin copolymer resin)
Preferred examples of the ethylene-α-olefin copolymer resin include resins of copolymers of ethylene and an α-olefin having 3 to 12 carbon atoms (excluding those corresponding to the above-mentioned polyethylene and polypropylene). Although it does not specifically limit as an alpha-olefin, For example, 1-propylene, 1-butene, 1-hexene, 4-methyl-1- pentene, 1-octene, 1-decene or 1-dodecene is mentioned. The ethylene-α-olefin copolymer may be used alone or in combination of two or more.

  0.05-10 g / 10min is preferable and, as for the melt flow rate of ethylene-alpha-olefin copolymer resin, 0.5-5 g / 10 min is more preferable. By setting the melt flow rate to 0.05 to 10 g / 10 min, it is possible to suppress foaming due to a gas or the like generated from a mixture with a benzimidazole based antioxidant, and to obtain a silane crosslinked resin molded article having an excellent appearance as well. . Moreover, there are cases where it is possible to obtain a silane cross-linked resin molded product which is excellent in tensile strength as compared to a polyethylene resin.

(Ethylene-α-olefin copolymer rubber)
The ethylene-α-olefin copolymer rubber is not particularly limited as long as it is a rubber composed of a copolymer of ethylene and the above α-olefin. For example, ethylene-propylene copolymer rubber (EP rubber (EPM)), which is a rubbery copolymer of ethylene and propylene can be mentioned. Here, an ethylene-propylene copolymer rubber means that whose ethylene component content is about 40-75 mass% normally. The content of the ethylene component in the ethylene-propylene copolymer rubber is preferably 50 to 75% by mass, more preferably 55 to 70% by mass. The ethylene component content is a value measured in accordance with the method described in ASTM D3900.

  Ethylene-α-olefin copolymer rubber is an ethylene-propylene terpolymer having a repeating unit having an unsaturated group as a third component other than ethylene and α-olefin (propylene) (eg, ethylene, α-olefin and diene) And terpolymers (EPDM) of In the present invention, either or both of EPM and EPDM may be used as the ethylene-α-olefin copolymer rubber.

  0.01-2 g / 10 min is preferable and, as for the melt flow rate of ethylene-alpha-olefin copolymer rubber, 0.1-1.5 g / 10 min is more preferable. By setting the melt flow rate to 0.01 to 2 g / 10 min, it is possible to suppress foaming due to a gas or the like generated from a mixture with a benzimidazole based antioxidant, and obtain a silane crosslinked resin molded article of excellent appearance . In addition, flexibility may also be imparted to the silane-crosslinked resin molded product.

(Polyolefin copolymer resin having an acid copolymer component or an acid ester copolymer component)
The acid copolymer component or acid ester copolymer component in the polyolefin copolymer resin having an acid copolymer component or acid ester copolymer component is not particularly limited, but carboxylic acid compounds such as (meth) acrylic acid, and acetic acid And acid ester compounds such as vinyl and alkyl (meth) acrylates. Here, the alkyl group of alkyl (meth) acrylate preferably has 1 to 12 carbon atoms. Examples of the polyolefin copolymer resin having an acid copolymerization component or an acid ester copolymerization component include ethylene-vinyl acetate copolymer (EVA), ethylene- (meth) acrylic acid copolymer, and ethylene- (meth) acrylic acid. An acid alkyl copolymer etc. are mentioned. The polyolefin copolymer having the acid copolymerization component or the acid ester copolymerization component may be used alone or in combination of two or more.

  0.05-10 g / 10min is preferable and, as for the melt flow rate of polyolefin copolymer resin which has an acid copolymerization component or an acid ester copolymerization component, 1-3 g / 10 min is more preferable. By setting the melt flow rate to 0.05 to 10 g / 10 min, it is possible to suppress foaming due to a gas or the like generated from a mixture with a benzimidazole based antioxidant, and to obtain a silane crosslinked resin molded article having an excellent appearance as well. . Moreover, it may be strongly bonded to the inorganic filler, and may give high tensile strength and abrasion resistance to the silane-crosslinked resin molded product.

(Ethylene acrylic rubber)
The ethylene acrylic rubber is not particularly limited, but a rubber elastic body composed of a copolymer obtained by copolymerizing ethylene with an alkyl acrylate such as ethyl acrylate or butyl acrylate as a component is preferable. Particularly preferably used is a rubber composed of a copolymer of ethylene and a copolymer of a terpolymer obtained by further copolymerizing an unsaturated hydrocarbon having a carboxy group in the side chain with the copolymer. Can. Examples of the ethylene acrylic rubber composed of a binary copolymer include Baymac DP and Baymac DLS. Examples of the ethylene acrylic rubber composed of a ternary copolymer include Baymac G, Baymac HG, Baymac LS, and Baymac GLS (trade names, all manufactured by Mitsui & Dupont Polychemicals Co., Ltd.).

  0.01-2 g / 10min is preferable and, as for the melt flow rate of ethylene acrylic rubber, 0.1-1 g / 10 min is more preferable. By setting the melt flow rate to 0.01 to 2 g / 10 min, it is possible to suppress foaming due to a gas or the like generated from a mixture with a benzimidazole based antioxidant and to obtain a silane-crosslinked resin molded article having an excellent appearance. . In addition, oil resistance and flame retardancy can be imparted to the silane-crosslinked resin molded product.

(Styrenic elastomer)
As a styrene-type elastomer, what has an aromatic vinyl compound as a structural component in a molecule | numerator is said. As such a styrene-type elastomer, the block copolymer and random copolymer of a conjugated diene compound and an aromatic vinyl compound, or those hydrogenated substances etc. are mentioned. As such a styrene-based elastomer, for example, styrene-ethylene-butylene-styrene block copolymer (SEBS), styrene-isoprene-styrene block copolymer (SIS), hydrogenated styrene-butadiene-styrene block copolymer (Hydrogenated SBS), styrene-ethylene-ethylene-propylene-styrene block copolymer (SEEPS), styrene-ethylene-propylene-styrene block copolymer (SEPS), styrene-butadiene rubber (SBR), hydrogenated SIS, Hydrogenated styrene-butadiene rubber (HSBR) etc. can be mentioned. The styrene-based elastomer may be used alone or in combination of two or more.
By containing a styrenic elastomer, foaming at the time of secondary processing of the silane-crosslinked resin molded article can be effectively suppressed. In particular, when a styrene-based elastomer is used in combination with another polyolefin resin, foaming during secondary processing can be further effectively suppressed. This suppression effect is enhanced particularly when using a styrene elastomer having a high molecular weight (molecular weight: about 100,000 to 500,000). The reason is considered to be that the flowability of the carrier resin can be effectively reduced.

  The polyolefin resin, i.e. the polymer may be acid modified. It does not specifically limit as an acid used for acid modification, The unsaturated carboxylic acid etc. which are normally used are mentioned.

-Mineral oil-
The mineral oil used in the present invention is a mixed oil comprising an oil having an aromatic ring, an oil having a naphthene ring and an oil having a paraffin chain. Paraffin oil means that the carbon number (CP) of paraffin chain is 50% or more and less than 75% of the total carbon number of aromatic ring, naphthene ring and paraffin chain, and the carbon number (CN) of naphthene chain is 20 or more and less than 40%, carbon number of the aromatic ring (CA) is 3 or more and less than 10%. Naphthenic oils are those with 40 to 60% CN, 30% to 50% CP, and 8% to 16% CA with respect to the total carbon number, and aromatic oils are CA Is said to be 16% or more.
As mineral oil (softener for rubber), paraffin oil or naphthene oil can be used, and paraffin oil is preferable in terms of mechanical strength.
The mineral oil preferably has a dynamic viscosity of 20 to 500 cSt at 40 ° C, a pour point of -10 to -15 ° C, and a flash point (COC) of 180 to 300 ° C.
Examples of the mineral oil include “Diana Process Oil” (trade name, manufactured by Idemitsu Kosan Co., Ltd.), “Cosmo Neutral” (trade name, manufactured by Cosmo Petroleum Lubricants, Inc.), and the like.

  The content of the polyolefin resin in 100% by mass of the carrier resin is preferably 60 to 100% by mass in total.

In the present invention, the content of each of the above resin components in the carrier resin is appropriately set in a range satisfying the above content of the polyolefin resin in the carrier resin, and can be set, for example, to the following content.
0-100 mass% is preferable in 100 mass% of carrier resins, and, as for the content rate of polyethylene resin, 40-100 mass% is more preferable.
The content of the polypropylene resin is preferably 0 to 100% by mass with respect to 100% by mass of the carrier resin, and the catalyst composition for silane crosslinking or the silane crosslinking resin composition can be prepared to be flowable for molding, suppressing appearance defects 20-60 mass% is more preferable from a viewpoint which can be carried out.
0-100 mass% is preferable in 100 mass% of carrier resin, 20-100 mass% is more preferable, and, as for the content rate of ethylene-alpha-olefin copolymer resin, 40-100 mass% is still more preferable.
0-100 mass% is preferable in 100 mass% of carrier resin, and, as for the content rate of ethylene-alpha-olefin copolymer rubber, 5-50 mass% is more preferable.
As for the content rate of the polyolefin copolymer which has an acid copolymerization component or an acid ester copolymerization component, 0-100 mass% is preferable in 100 mass% of carrier resins. The function and effect of the present invention are not impaired, but from the viewpoint of being able to suppress adhesion of the catalyst MB to metal parts such as devices, 0 to 50% by mass is more preferable, and 5 to 30% by mass is particularly preferable.
0-100 mass% is preferable in 100 mass% of carrier resins, and, as for the content rate of ethylene acrylic rubber, 5-50 mass% is more preferable.
20 mass% or more is preferable in 100 mass% of carrier resins, and, as for the content rate of a styrene-type elastomer, 25-50 mass% is more preferable.

  0-40 mass% is preferable in 100 mass% of carrier resins, and, as for the content rate of mineral oil, 10-40 mass% is more preferable. When the content of the mineral oil is in the above range, generation of bumps can be suppressed, and bleeding out of the mineral oil can be prevented. As a result, a silane cross-linked resin molded product having an excellent appearance can be produced.

  It is also preferable to use a low density polyethylene, a styrenic elastomer, and a mineral oil in combination from the viewpoint of suppressing the generation of gel butts during extrusion molding, and the content of each component in this case is set to the above range. However, it is preferable to set the low density polyethylene 40 to 80% by mass, the styrenic elastomer 10 to 40% by mass, and the mineral oil 10 to 40% by mass in 100% by mass of the carrier resin.

<Silanol condensation catalyst>
The silanol condensation catalyst has a function of causing a silanol condensation reaction (promoting) of a hydrolyzable silyl group derived from a silane coupling agent in a silane graft resin described later in the presence of water. Based on the function of the silanol condensation catalyst, the resins forming the silane graft resin are crosslinked via the silane coupling agent. Therefore, the silane-crosslinked resin molded product obtained is excellent in heat resistance and, if necessary, in strength.
The silanol condensation catalyst used in the present invention is not particularly limited, and examples thereof include organic tin compounds, metal soaps, and platinum compounds. Specifically, organotin compounds such as dibutyltin dilaurate, dioctyltin dilaurate, dibutyltin diacrylate, dibutyltin diacetate, etc., zinc stearate, lead stearate, barium stearate, calcium stearate, sodium stearate, sodium stearate, lead naphthenate, sulfuric acid Lead, zinc sulfate, organic platinum compounds and the like can be mentioned.
The silanol condensation catalyst may be used alone or in combination of two or more.

  The content of the silanol condensation catalyst in the silane crosslinking catalyst composition is 0.05 to 5 parts by mass, and more preferably 0.3 to 2 parts by mass with respect to 100 parts by mass of the carrier resin. By setting the content of the silanol condensation catalyst in the above range, it can be suitably used for crosslinking of the silane graft resin. However, the content of the silanol condensation catalyst is appropriately determined in consideration of the mixing ratio with the silane graft resin composition to be used in combination, the required characteristics of the silane cross-linked resin molded product, and the like. Although the details will be described later, the content of the silanol condensation catalyst in the catalyst composition for silane crosslinking and the mass ratio described later with respect to the total amount of the carrier resin and the base resin contained in the silane graft resin composition Preferably, the mixing ratio of the silane crosslinking catalyst composition is set.

<Anti-aging agent>
The catalyst composition for silane crosslinking of the present invention contains 15 to 50 parts by mass of a benzimidazole based antioxidant with respect to 100 parts by mass of a carrier resin, and 25 parts by mass or less of a hydrazine based heavy metal deactivator. The catalyst composition for silane crosslinking of the present invention may further contain a phenolic antioxidant. In the present invention, the benzimidazole antioxidant, the hydrazine heavy metal deactivator, and the phenolic antioxidant may be collectively referred to as "anti-aging agent".
The antiaging agent has a function to suppress deterioration of the silane-crosslinked resin molded product in long-term use and to enhance aging resistance.

  The benzimidazole based antioxidant is not particularly limited as long as it is generally used in the field of wiring materials and the like. For example, a zinc salt of 2-mercaptobenzimidazole (Nocrac MBZ, trade name, 1,3-dihydro-2H-benzoimidazole-2-thione, 0.5 zinc, manufactured by Ouchi Emerging Chemical Industry Co., Ltd.) and the like can be mentioned. The benzimidazole based antioxidant may be used alone or in combination of two or more.

  The hydrazine heavy metal deactivator is not particularly limited as long as it is generally used in the field of wiring materials and the like. For example, 1,2-bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyl] hydrazine (ADEKA STAB CDA-10 (trade name), manufactured by ADEKA Corporation), 1,2-bis [ 3- (4-hydroxy-3,5-di-tert-butylphenyl) propionyl] hydrazine (IRGANOX MD 1024 (trade name), manufactured by BASF Corp.) and the like can be mentioned. The hydrazine heavy metal deactivator may be one kind or two or more kinds.

  The phenolic antioxidant is not particularly limited as long as it is usually used in the field of wiring materials and the like. For example, hindered phenolic anti-aging agents are preferable, for example, octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate (IRGANOX 1076 (trade name), manufactured by BASF) or penta Erythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate (IRGANOX 1010 (trade name), manufactured by BASF Corp.) and N, N'-bis 3- (3'5'-) Di-t-butyl-4'-hydroxyphenyl) propionyl hexamethylene diamine (IRGANOX 1098 (trade name), manufactured by BASF) and the like can be mentioned, among which IRGANOX 1010 is preferable. The phenolic antioxidant may be used alone or in combination of two or more.

  In the present invention, the antiaging agent is a hydrazine based heavy metal deactivator even if it has a phenol structure and / or a benzimidazole structure in addition to the hydrazine structure in the molecule. In addition to the benzimidazole structure in the molecule, the anti-aging agent is a benzimidazole-based anti-aging agent even if it has a phenol structure.

  In the present invention, the catalyst composition for silane crosslinking may contain at least a benzimidazole-based anti-aging agent as an anti-aging agent; It may contain one or both of the inhibitors. The combination of these anti-aging agents is appropriately determined, for example, to suppress the aging (deterioration) of the cross-linked body due to the contact of the wiring material with the conductor (metal), and general aging other than aging due to the contact with metal. From the viewpoint of suppressing simultaneously, it is preferable to use a benzimidazole based antioxidant and a hydrazine based heavy metal deactivator in combination. On the other hand, it is preferable to use a benzimidazole based antioxidant and a phenolic based antioxidant in combination from the viewpoint of imparting to the crosslinked body at a higher level general aging resistance other than aging due to contact with the metal. . Furthermore, from the viewpoint of achieving the above-mentioned properties, it is preferable to use a benzimidazole based antioxidant, a hydrazine based heavy metal deactivator, and a phenolic based antioxidant together.

The content of the benzimidazole-based antioxidant is 15 to 50 parts by mass, preferably 20 to 45 parts by mass, and more preferably 30 to 40 parts by mass with respect to 100 parts by mass of the carrier resin. Within this range, both suppression of foaming and excellent aging resistance can be achieved, and furthermore, the appearance is also excellent.
The content of the hydrazine-based heavy metal deactivator is 0 to 25 parts by mass with respect to 100 parts by mass of the carrier resin. When the content is 25 parts by mass or less, foaming can be suppressed. From the point of coexistence of suppression of foaming and suppression of deterioration due to contact with metal, 5 to 20 parts by mass is preferable, and 10 to 15 parts by mass is more preferable.
The content of the phenolic antioxidant is preferably 0 to 30 parts by mass, more preferably 5 to 20 parts by mass, and still more preferably 10 to 15 parts by mass with respect to 100 parts by mass of the carrier resin. Within this range, both suppression of foaming and excellent aging resistance can be achieved.
From the viewpoint of aging resistance, although depending on the type of antiaging agent to be combined, it is preferable to set the total content of the antiaging agent to a high blending amount of about 25 to 100 parts by mass with respect to 100 parts by mass of the carrier resin. . More preferably, it is 45-70 mass parts.

<Additives>
The catalyst composition for silane crosslinking includes various additives generally used in electric wires, electric cables, electric cords, automobile members, OA devices, building members, sundries, sheets, foams, tubes, pipes, etc. You may contain suitably in the range which does not impair the aimed effect. As such an additive, for example, a crosslinking assistant, a lubricant, a metal deactivator, a flame retardant (auxiliary), and a resin other than the above resin component can be mentioned.
The crosslinking coagent refers to a compound which forms a partially crosslinked structure between resin components in the presence of an organic peroxide. For example, polyfunctional compounds and the like can be mentioned.
As the lubricant, lubricants such as hydrocarbons, siloxanes, fatty acids, fatty acid amides, esters, alcohols, metal soaps and the like can be mentioned.

  The melt flow rate of the silane crosslinking catalyst composition is 0.1 to 15 g / 10 min. By setting MFR to 0.1 to 15 g / 10 min, foaming can be suppressed at the time of preparation of the catalyst composition for silane crosslinking. Moreover, when it uses for the silane crosslinking method, the silane crosslinking resin composition excellent in the moldability can be obtained. The MFR is more preferably 0.5 to 10 g / 10 min, and still more preferably 1 to 3 g / 10 min, in terms of achieving both foam suppression and formability at a higher level.

The catalyst composition for silane crosslinking of the present invention can be prepared at the time of preparation of the catalyst composition for silane crosslinking, even if the benzimidazole antioxidant and the hydrazine heavy metal deactivator are used, particularly if the content thereof is increased. It is possible to suppress foaming during secondary processing of a wiring material obtained using the catalyst composition for silane crosslinking, and further, excellent heat resistance and aging resistance to a crosslinked product of a silane graft resin. And it can give the appearance. Although the reason is not clear, it is considered as follows.
According to the findings of the present inventors, a gas is generated when a silanol condensation catalyst and an antiaging agent (particularly, a benzimidazole based antioxidant and a hydrazine based heavy metal deactivator) come in contact with each other or a decomposition product thereof under high temperature. Do. The evolution of gas is particularly pronounced at high loadings of anti-aging agents. However, in the present invention, the catalyst composition for silane crosslinking contains a polyolefin resin as a carrier resin, and contains a specific amount of silanol condensation catalyst and an antiaging agent, and the melt flow rate is within the above range and the flow Sex is low. As a result of the cooperation of these, even if a gas is generated, the resin component is not easily expanded by this gas, and the gas is easily discharged to the outside of the silane crosslinking catalyst composition. Therefore, it is considered that the gas generated at the time of preparation of the catalyst composition for silane crosslinking is unlikely to remain and foaming is suppressed.
On the other hand, at the time of secondary processing of the silane-crosslinked resin molded product, the silanol condensation catalyst usually disappears, and the generation of gas due to the contact with the anti-aging agent does not occur. However, it is considered that the silane-crosslinked resin molded product contains a gas or the like remaining in the silane crosslinking catalyst composition or a low molecular weight component or the like. When a silane-crosslinked resin molded product containing such components is subjected to secondary processing at a temperature higher than that at the time of preparation, these components (air bubbles) may be expanded to cause foaming. However, even if the silane cross-linked resin molded product of the present invention is subjected to secondary processing, foaming due to the above components can be suppressed. Furthermore, foaming can be suppressed also under high temperature at the time of preparing the silane crosslinking resin composition using the catalyst composition for silane crosslinking, and its silane crosslinking resin molded object.
In general, when the flowability is low, the formability, particularly the high-speed formability, is deteriorated, and appearance defects and formation of bumps are observed. However, the catalyst composition for silane crosslinking of the present invention is excellent in fluidity, the gas generated as described above is unlikely to remain, and a silane crosslinking resin composition containing such a catalyst composition for silane crosslinking is molded Foaming at the time can be suppressed. For this reason, it is considered that molding at a relatively high temperature is possible, and a wiring material having an excellent appearance can be obtained.
Furthermore, by using the catalyst composition for silane crosslinking of the present invention, the silane crosslinkable resin composition is subjected to silane crosslinking to exhibit high heat resistance without impairing the above-mentioned foam suppressing effect and appearance, and a high content is achieved. The aging resistance which was excellent by the anti-aging agent to be contained can be provided to a silane crosslinked resin molded article.

<Method of producing catalyst composition for silane crosslinking>
The catalyst composition for silane crosslinking is obtained by heat-mixing (kneading) the carrier resin, the benzimidazole antioxidant, the silanol condensation catalyst, and, if necessary, various additives. The heating temperature can be set above the melting temperature of the carrier resin, and is preferably set, for example, at 150 to 230 ° C. Other conditions, for example, the mixing time can be set as appropriate.
As a mixing method, a method commonly used for rubber, plastic and the like can be adopted without particular limitation. As a mixing apparatus, a single screw extruder, a twin screw extruder, a roll, a Banbury mixer, or various kneaders etc. are used, for example.

  In the catalyst composition for silane crosslinking of the present invention, the method of setting MFR to 0.1 to 15 g / 10 min is not particularly limited, but, for example, the type, MFR or content of the polyolefin resin (the above respective resin components) Is a method of changing the type or content of each anti-aging agent. Besides this, a method of adding a lubricant may also be mentioned. In the present invention, the MFR is set as needed.

[Silane Crosslinkable Resin Composition]
Next, the silane crosslinkable resin composition of the present invention will be described.
The silane crosslinkable resin composition of the present invention is a melt mixture of a silane graft resin composition containing a base resin containing a silane graft resin as a resin component, and the catalyst composition for silane crosslinking of the present invention. The silane crosslinkable resin composition is obtained by melt mixing the silane graft resin composition and the silane crosslinking catalyst composition of the present invention. In the silane crosslinkable resin composition, it is desirable that the hydrolyzable silyl group derived from the silane coupling agent is not condensation-reacted, but some condensation may occur during melting or the like. Even in this case, the hydrolyzable silyl group is prepared by suppressing the condensation reaction to such an extent that the silane crosslinkable resin composition has moldability in the molding step described later.
The silane-crosslinkable resin composition of the present invention is excellent in moldability and enables molding at a relatively high speed. In addition, it is possible to obtain a silane-crosslinked resin molded product excellent in heat resistance, aging resistance and appearance. The silane crosslinking resin composition of the present invention can also be prepared by suppressing foaming at the time of preparation.

<Silane graft resin composition>
The silane graft resin composition (silane master batch: silane MB) is a composition containing a base resin containing a silane graft resin, and an aspect consisting of a base resin (an aspect of using a base resin alone), a base resin, and necessary According to the above, the embodiment includes both the embodiments including the other components (the embodiment used as a composition). In addition, the base resin contained in the silane graft resin composition is an aspect comprising a silane graft resin (an aspect in which the silane graft resin is used alone), an aspect containing the silane graft resin, and other components as necessary ( It includes both aspects of the aspect used as a resin mixture.
When the silane graft resin is synthesized according to the step (a) or the like described later, the silane graft resin composition and the base resin are a condensation product of an organic peroxide decomposition product, an unreacted silane coupling agent and a silane coupling agent You may contain unreacted substances, such as a thing, or a by-product.

-Base resin-
The base resin contains a silane graft resin, and optionally contains other components. However, the base resin does not contain the inorganic filler described later.
(Silane graft resin)
The silane graft resin is formed by subjecting a resin to a grafting reaction (bonding reaction between a crosslinkable group of the silane coupling agent and a crosslinking site of a resin component) of a silane coupling agent having a hydrolyzable silyl group. The silane graft resin is formed of a silane coupling agent and a resin, and has a constituent component derived from the silane coupling agent as a graft chain (pendent).
In this silane graft resin, the grafting reaction amount of the silane coupling agent is not particularly limited. In general, the grafting reaction amount obtained by reacting the silane coupling agent and the resin in the compounding amount described later may be used.

The resin forming the silane graft resin is capable of grafting reaction in the presence of a site capable of grafting reaction of the silane coupling agent (also referred to as a grafting reaction site) and, for example, radicals generated by decomposition of the organic peroxide. (For example, unsaturated bond sites of a carbon chain, and a polymer component having a carbon atom having a hydrogen atom in or at the end of the main chain). Such a polymer component is not particularly limited, but a polyolefin resin is preferable, and in addition to the polyolefin resin, a resin component having a graftable reaction site may be contained.
The polyolefin resin is not particularly limited as long as it is a resin comprising a polymer obtained by homopolymerization or copolymerization of a compound having an ethylenically unsaturated bond, and it is known that it is conventionally used in a resin composition. Can be used. For example, the polyolefin resin described in the above carrier resin can be mentioned. Moreover, the acid modified resin which modified | denatured this resin by the unsaturated carboxylic acid is also mentioned.
The resin is preferably ethylene-vinyl acetate copolymer (EVA), ethylene- (meth) acrylate copolymer (for example, ethylene-ethyl acrylate copolymer resin), low density polyethylene, etc., and low density polyethylene Is more preferred.
The resin forming the silane graft resin may be used alone or in combination of two or more.

As a silane coupling agent for forming a silane graft resin, a grafting reaction site (group or atom) capable of grafting reaction to a site capable of grafting reaction of the above-mentioned resin, and a hydrolyzable silyl group capable of silanol condensation There is no particular limitation as long as it is possessed. The grafting reaction site (group or atom) is preferably, for example, one that can undergo a grafting reaction in the presence of a radical generated by decomposition of the organic peroxide.
As such a silane coupling agent, the silane coupling agent conventionally used for the silane crosslinking method is mentioned. Among them, those having a vinyl group and an alkoxysilyl group at the end are preferable. As such a silane coupling agent, for example, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltributoxysilane, vinyldimethoxyethoxysilane, vinyldimethoxybutoxysilane, vinyldiethoxybutoxysilane, allyltrimethoxysilane, allyltriethoxy Examples thereof include silane, vinylsilane such as vinyltriacetoxysilane, and (meth) acryloxysilane such as methacryloxypropyltrimethoxysilane, methacryloxypropyltriethoxysilane, and methacryloxypropylmethyldimethoxysilane. Among them, vinyltrimethoxysilane or vinyltriethoxysilane is particularly preferable.
The silane coupling agent that forms the silane graft resin may be used alone or in combination of two or more.

  As the silane graft resin, one synthesized by a known method or a method described later may be used, or a commercially available product may be used. Commercially available products include Lincron (trade name, manufactured by Mitsubishi Chemical Corporation) and the like.

When synthesizing a silane graft resin, it is preferable to use an organic peroxide. The organic peroxide generates radicals at least by thermal decomposition, and the grafting reaction by the radical reaction of the silane coupling agent to the resin (the grafting reaction site of the silane coupling agent and the graftable reaction site of the polyolefin resin) And (also referred to as (radical) addition reaction). For example, when the silane coupling agent contains an ethylenically unsaturated group as a grafting reaction site, the grafting reaction by the radical reaction (including the abstraction of hydrogen radicals from the polyolefin resin) of the ethylenically unsaturated group and the polyolefin resin is It works to make it happen. The organic peroxide is not particularly limited as long as it generates a radical, and, for example, general formulas: R ¹ -OO-R ² , R ³ -OO-C (= O) R ⁴ , R ⁵ C (= O) -OO (C = O) compounds represented by ^{R 6} is preferably. Here, R ^{1 to} R ⁶ each independently represent an alkyl group, an aryl group or an acyl group. Among R ^{1 to} R ⁶ of each compound, preferred are those in which all are alkyl groups, or those in which either is an alkyl group and the remainder is an acyl group.

  As such an organic peroxide, for example, dicumyl peroxide (DCP), di-tert-butyl peroxide, 2,5-dimethyl-2,5-di- (tert-butylperoxy) hexane, 2 5-dimethyl-2,5-di (tert-butylperoxy) hexyne-3, 1,3-bis (tert-butylperoxyisopropyl) benzene, 1,1-bis (tert-butylperoxy) -3 , 3,5-trimethylcyclohexane, n-butyl-4,4-bis (tert-butylperoxy) valerate, benzoyl peroxide, p-chlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, tert-butylperoxide Oxybenzoate, tert-butylperoxyisopropyl carbonate, diaceto Peroxide, lauroyl peroxide, may be mentioned tert- butyl cumyl peroxide and the like. Among these, dicumyl peroxide, 2,5-dimethyl-2,5-di- (tert-butylperoxy) hexane, 2,5-dimethyl-2 in terms of odor, color and scorch stability. Preferred is 5-di (tert-butylperoxy) hexyne-3.

80-195 degreeC is preferable and, as for the decomposition temperature of an organic peroxide, 125-180 degreeC is especially preferable.
In the present invention, the decomposition temperature of the organic peroxide means a temperature at which a decomposition reaction occurs in two or more kinds of compounds in a certain temperature or temperature range when heating the organic peroxide of a single composition. means. Specifically, it refers to a temperature at which heat absorption or heat generation starts when heated from room temperature at a temperature rising rate of 5 ° C./minute in a nitrogen gas atmosphere by thermal analysis such as DSC method.

  The silane graft resin is obtained by reacting the resin and the silane coupling agent at a temperature above the decomposition temperature of the organic peroxide. Specific reaction conditions include melt mixing conditions of step (a) described later.

(Other components that the base resin may contain)
Although it does not restrict | limit especially as another component which base resin may contain, Resin other than silane graft resin, mineral oil, etc. are mentioned. As resin and mineral oil other than silane graft resin, polyolefin resin and mineral oil which were explained in the above-mentioned carrier resin are mentioned.
The content of the silane graft resin in 100% by mass of the base resin is preferably 50 to 100% by mass.
The base resin preferably contains a styrene-based elastomer as a resin other than the silane graft resin. The content of the styrene-based elastomer in the base resin is preferably 10% by mass or more, and more preferably 10 to 40% by mass.
The base resin, in particular the base resin containing a styrenic elastomer, may contain the mineral oil described above. The content of the mineral oil in the base resin is preferably 0 to 30% by mass.

  When the base resin is used as a resin mixture, the base resin can be prepared by mixing the silane graft resin and the other components by a common mixing method.

-Other components which the silane graft resin composition may contain-
The other component which the silane graft resin composition may contain is not particularly limited as long as it is a component other than the other component which the above-mentioned base resin may contain, and an inorganic filler and a catalyst composition for silane crosslinking are included. The above-mentioned various additives etc. which may be contained are mentioned.

(Inorganic filler)
The inorganic filler which may be contained in the silane graft resin composition is not particularly limited as long as it is usually used, and the surface thereof may be a hydrolyzable silyl group of a silane coupling agent or a hydrogen bond or a covalent bond or the like It is preferable to have a site capable of chemically bonding, etc. by intermolecular bonding. Examples of the site that may be chemically bonded to the hydrolyzable silyl group include an OH group (hydroxyl group, water molecule of water or water of crystallization, OH group such as carboxy group), an amino group, an SH group and the like.
When such an inorganic filler is used particularly in the step (a) described later, a silane graft resin in which a silane coupling agent which is weakly bonded to the inorganic filler is graft-reacted, and a silane coupling agent which is strongly bonded to the inorganic filler are grafted. And the reacted silane graft resin can be formed. By cross-linking reaction of such two types of silane graft resins, it is possible to form a silane cross-linked resin molded product having both heat resistance and strength.
Here, as the weak bond with the inorganic filler, an interaction by hydrogen bond, an interaction among ions, partial charges or dipoles, an action by adsorption, and the like can be mentioned. Moreover, as a strong bond with the inorganic filler, a chemical bond with a site capable of chemically bonding on the surface of the inorganic filler and the like can be mentioned.

The above-mentioned inorganic filler is not particularly limited, and, for example, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, aluminum oxide, aluminum borate, aluminum borate Examples thereof include metal hydrates such as whiskers, hydrated aluminum silicates, hydrated magnesium silicates, basic magnesium carbonate, hydrotalcite, and compounds having a hydroxyl group or crystallization water such as talc. Also, boron nitride, silica (crystalline silica, amorphous silica, etc.), carbon, clay, zinc oxide, tin oxide, titanium oxide, titanium oxide, molybdenum oxide, antimony trioxide, silicone compound, quartz, zinc borate, white carbon, Zinc borate, zinc hydroxystannate, zinc stannate and the like can also be mentioned. Among them, aluminum hydroxide or magnesium hydroxide is preferable.
An inorganic filler can also be used for what was surface-treated by various surface treatment agents.
One type of inorganic filler may be used alone, or two or more types may be used in combination.
The content of the inorganic filler in the silane graft resin composition is not particularly limited, and can be set as appropriate. Preferably, it is set so that it will become a compounding quantity in a process (a2) mentioned below to a total of 100 mass parts of career resin and base resin.

The silane graft resin composition can be prepared by mixing the base resin and the above-mentioned other components by a common mixing method, and can also be prepared as in the step (a) described later. In the present invention, it is preferable to prepare as step (a) described later.
In addition, when base resin contains the said other component, the resin mixture prepared beforehand may be used as base resin, and you may use silane graft resin and another component separately.

[Kit for preparing silane cross-linked resin molded product]
The catalyst composition for silane crosslinking of the present invention can also be used as a kit for preparing a silane crosslinked resin molded article which is combined with a silane graft resin composition.
In the silane crosslinked resin molded body preparation kit, a silane graft resin may be used alone as the silane graft resin composition and combined with the silane crosslinking catalyst composition.
The kit for preparing a silane-crosslinked resin molded product may be used in any production method as long as it can produce a silane-crosslinked resin molded product. Preferably, it is used for the manufacturing method of the silane crosslinked resin molded object mentioned later, especially the process (b) of this manufacturing method.
In the silane crosslinked resin molded body preparation kit, the mixing ratio of the silane graft resin composition and the silane crosslinking catalyst composition is not particularly limited, but at least when used, it should be used at the mixing ratio described in step (b) described later. Is preferred.

[Manufacturing method of silane crosslinkable resin composition, silane crosslinked resin molded article and wiring material]
Next, a method for producing a silane crosslinkable resin composition, a silane crosslinkable resin molded article and a wiring material using the catalyst composition for silane crosslinking of the present invention will be described.

The method for producing a silane crosslinkable resin composition includes, for example, a step of melt-mixing a silane graft resin composition and the catalyst composition for silane crosslinking of the present invention. Melt mixing can be applied without any particular limitation to the usual method (conditions) and apparatus, for example, the method (conditions) and apparatus described in the melt mixing in step (b) of the method for producing a silane cross-linked resin molded product described below Is applicable.
The method for producing the silane-crosslinked resin molded product is not particularly limited as long as it is a silane crosslinking method using the catalyst composition for silane crosslinking of the present invention, and a common silane crosslinking method can be applied. For example, the silane crosslinking method which has the following process (b) and (c) is mentioned.
Step (b): a step of melt-mixing the silane graft resin composition and the catalyst composition for silane crosslinking of the present invention and then molding the same Step (c): the molded product (of the molten mixture) obtained in step (b) Step of Crosslinking by Contact with Water The method of producing the wiring material may be any method as long as the coating layer can be formed of a cured product of the silane crosslinkable resin composition, for example, the method of producing a silane cross-linked resin molded article The method is mentioned.

Hereinafter, the steps (b) and (c) in the method for producing a silane crosslinked resin molded product will be described in order.
The melt mixing method of the silane graft resin composition and the silane crosslinking catalyst composition of the present invention in the step (b) is not particularly limited as long as it is a method generally used for rubber, plastic and the like. A mixing apparatus is suitably selected according to the compounding quantity of an inorganic filler, for example. As a mixing apparatus, a single screw extruder, a twin screw extruder, a roll, a Banbury mixer, various kneaders, etc. are used. From the viewpoint of dispersibility of the resin component, it is preferable to use a closed mixer such as a Banbury mixer or various kneaders. The melting temperature is appropriately selected according to the melting temperature of the base resin or the carrier resin, and is, for example, preferably 80 to 250 ° C., more preferably 100 to 240 ° C. Other conditions, for example, the mixing time can be set as appropriate. Step (b) is carried out by suppressing the silanol condensation reaction of the coupling agent grafted onto the resin. For example, it is preferable to carry out under conditions where the amount of water present is small, and it is also preferable that the mixture of the silane graft resin composition and the silanol condensation catalyst is not kept in a high temperature state for a long time.

  Prior to melt mixing of the silane graft resin composition and the catalyst composition for silane crosslinking of the present invention, dry blending can be performed. The method and conditions of dry blending are not particularly limited, and examples thereof include dry mixing and conditions thereof in step (a2-1) described later.

  The mixing ratio of the silane graft resin composition and the silane crosslinking catalyst composition of the present invention is preferably set from the viewpoint of the mixing ratio of the silanol condensation catalyst or the carrier resin.

The mixing ratio of the silanol condensation catalyst is 0.02 to 0.5 based on the total 100 parts by mass of the base resin in the silane graft resin composition and the carrier resin in the silane crosslinking catalyst composition of the present invention. Preferably, it is set to parts by mass. That is, the silane crosslinking catalyst composition of the present invention and the silane graft resin composition are mixed at a ratio of 0.02 to 0.5 parts by mass of the silanol condensation catalyst with respect to the total 100 parts by mass. preferable. When the mixing ratio of the silanol condensation catalyst is in this range, appearance defects and generation of bumps can be effectively suppressed, and the crosslinking reaction in step (c) to be described later can be sufficiently advanced. Therefore, the obtained silane crosslinkable resin composition can be made excellent in moldability, and high heat resistance can be imparted to the obtained silane cross-linked resin molded product. The mixing ratio of the silanol condensation catalyst is preferably 0.05 to 0.4 parts by mass, more preferably 0.08 to 0.3 parts by mass with respect to 100 parts by mass in total.
Here, when the silane graft resin composition is synthesized and used in the step (a) described later, the amount (parts by mass) of the base resin is the resin used to synthesize the silane graft resin (a resin forming the silane graft resin) ), A silane coupling agent, a resin other than a silane graft resin, and a mineral oil.

  The mixing ratio of the carrier resin is preferably set to 2 to 60% by mass in 100% by mass in total of the base resin and the carrier resin. That is, the carrier resin is preferably mixed with the silane graft resin composition in a proportion of 2 to 60% by mass in the total 100% by mass. When the mixing ratio of the carrier resin is in this range, generation of bumps can be effectively suppressed, and the crosslinking reaction can be sufficiently advanced in the process described later. The mixing ratio of the carrier resin is more preferably set to 15 to 40% by mass, and further preferably set to 18 to 35% by mass.

Thus, a molten mixture (silane crosslinkable resin composition) can be obtained. The content of each component in this melt mixture is the content of the corresponding component in the silane graft resin composition and the catalyst composition for silane crosslinking of the present invention, the silane graft resin composition, and the catalyst composition for silane crosslinking of the present invention And the mixing ratio at the time of melt mixing.
For example, in a silane crosslinkable resin composition using a silane graft resin composition in which the base resin contains 10% by mass or more of a styrene-based elastomer, the content of the styrene-based elastomer is 100% by mass in total of the base resin and the carrier resin. On the other hand, it is preferable that it is 5 mass% or more.
In addition, for example, in the silane crosslinkable resin composition, the content of the silane graft resin is preferably 50 to 100% by mass, and 60 to 90% by mass with respect to 100% by mass in total of the base resin and the carrier resin. It is more preferable that

In step (b), the resulting molten mixture is shaped.
In this molding step, a molten mixture can be molded, and an appropriate molding method and molding conditions are selected according to the form of the silane cross-linked resin molded product. The molding method includes extrusion molding using an extruder, extrusion molding using an injection molding machine, and molding using another molding machine.
Extrusion is preferably applied when the product comprising the silane cross-linked resin molding is a wiring material, in particular a wire or an optical fiber cable. Extrusion can be performed using a general-purpose extruder. The extrusion temperature depends on the type of base resin or carrier resin and conditions of extrusion speed (take-up speed), but the cylinder part is 120 to 150 ° C and the crosshead part (die temperature) is about 160 to 200 ° C. It is preferable to set to.
When the molding in step (b) is carried out by extrusion, the molding speed (extrusion speed) of the molten mixture is not particularly limited, and is usually set to less than 1 to 20 mm / min, preferably 1 to 10 mm / min at linear velocity. it can. Further, in the present invention, the molding speed can be set to a high speed of 20 to 200 mm / min as a linear speed in order to further improve the productivity.

  In the step (b), the forming step can be performed simultaneously with or sequentially to the melt mixing step. That is, as an embodiment of melt mixing in the melt mixing step, for example, an embodiment in which a molding material (silane graft resin composition and catalyst composition for silane crosslinking of the present invention) is melted and mixed immediately before or during extrusion molding can be mentioned. For example, the molding materials may be mixed at normal temperature or high temperature (in a non-molten state), introduced into a molding machine, and melted and mixed. Alternatively, the molding material may be melt mixed and pelletized, and then introduced into a molding machine to be melt mixed again. In this case, more specifically, the mixture of the silane graft resin composition and the catalyst composition for silane crosslinking of the present invention is melt mixed in a coating apparatus, and then extrusion coated on the outer peripheral surface of a conductor or the like, A series of steps can be employed to form the shape of. Thus, dry blending is performed by dry blending the silane graft resin composition and the catalyst composition for silane crosslinking of the present invention, and the dry blend is introduced into a molding machine to be shaped, thereby forming silane crosslinkability. A crosslinkable resin molded product is obtained as a molded product of the resin composition.

The crosslinkable resin molded product obtained in the step (b) is an uncrosslinked product in which the hydrolyzable silyl group derived from the silane coupling agent is not subjected to silanol condensation. In practice, partial cross-linking (partial cross-linking) can not be avoided when melt-blended in step (b), but at least the moldability of the resulting crosslinkable resin molded article is maintained. It is preferable to do. It is also preferable not to reduce the appearance.
When using and synthesize | combining and using a silane graft resin composition by process (a) mentioned later, as for a crosslinkable resin molding, one part hydrolysable silyl group may couple | bond with or adsorb | suck an inorganic filler. In this case, in the crosslinkable resin molded product, the silane graft resin grafted with the silane coupling agent bonded or adsorbed to the inorganic filler by the hydrolyzable silyl group and the hydrolyzable silyl group are not bonded or adsorbed to the inorganic filler And a silane graft resin grafted with a silane coupling agent.

In the step (c), the crosslinkable resin molded product obtained in the step (b) is brought into contact with water. By carrying out the step (c), the crosslinkable resin molded article is made into a (final) crosslinked silane crosslinked resin molded article. That is, the hydrolyzable silyl group which the silane graft resin has is hydrolyzed to become silanol (OH group bonded to a silicon atom), and the hydroxyl groups of silanol are (dehydrated) by the silanol condensation catalyst present in the crosslinkable resin molded product By condensation, a crosslinking reaction takes place.
The treatment itself of this step (c) can be performed by a conventional method. The above condensation reaction proceeds in the presence of a silanol condensation catalyst only by storage at normal temperature. Therefore, in the step (c), the crosslinkable resin molded product does not have to be positively contacted with water. In order to accelerate this condensation reaction, the crosslinkable resin molding can also be contacted with water. For example, it is possible to adopt a method in which water is actively brought into contact such as water immersion in warm water, charging to a moist heat tank, exposure to high temperature water vapor and the like. In addition, pressure may be applied to allow water to permeate inside.
Thus, a silane cross-linked resin molded product is produced.

The silane graft resin composition used in the step (b) may be a commercial product or a preparation (synthetic product). The method for preparing the silane graft resin composition is not particularly limited, and examples thereof include a method using a commercially available silane graft resin and a method including a synthesis step of the silane graft resin.
As a method of using a commercially available silane graft resin, for example, a method of mixing a silane graft resin, a base resin component other than the silane graft resin, an inorganic filler and the like can be mentioned. The mixing method and the mixing conditions are not particularly limited, and can be set as appropriate.

  As a method including a synthesis step (a) of a silane graft resin, for example, a method including a step (a1) of synthesizing a silane graft resin without using an inorganic filler and a silane graft resin synthesized in the presence of an inorganic filler Preferred is a method including step (a2). In the present invention, step (a1) is preferred. The step (a2) is preferable from the viewpoint of promoting the crosslinking to improve the heat resistance.

That is, the preferable one aspect | mode of the manufacturing method of a silane crosslinked resin molded object has following process (a1) and said process (b) and (c). The silane graft resin composition obtained in the step (a1) is used in the above step (b).
Step (a1): A resin that forms a silane graft resin to be contained in the base resin when the base resin and the carrier resin to be mixed in step (b) are 100 parts by mass in total (hereinafter, for forming a silane graft resin Resin), 0.003 to 0.3 parts by mass of an organic peroxide, and 2 parts by mass of a silane coupling agent having a grafting reaction site, and 15.0 parts by mass or less of the organic peroxide A silane containing a base resin containing a silane graft resin by melting and mixing at a temperature above the decomposition temperature and causing a silane coupling agent to graft onto the resin for forming a silane graft resin by radicals generated from an organic peroxide. Step of obtaining a graft resin composition Another preferred embodiment of the method for producing a silane-crosslinked resin molded article is the following step (a2): In place of). The silane graft resin composition containing an inorganic filler obtained by the step (a2) is used in the above step (b).
Step (a2): The resin for forming a silane graft resin and the organic peroxide 0.003 to 0.3 parts by mass, based on 100 parts by mass in total of the base resin and the carrier resin to be mixed in step (b) And 10 to 400 parts by mass of an inorganic filler and 25.0 parts by mass or less of a silane coupling agent having a grafting reaction site by melting and mixing at a temperature above the decomposition temperature of the organic peroxide And a step of obtaining a silane graft resin composition containing a base resin containing a silane graft resin by causing a silane coupling agent to graft onto a resin for forming a silane graft resin by radicals generated from an organic peroxide. In (a1) and (a2), if necessary, resins other than the above-mentioned silane graft resin, mineral oil and additives may be mixed. The compounding quantity of resin and mineral oil other than silane graft resin is determined in consideration of the compounding quantity of resin for silane graft resin formation. The compounding quantity of an additive is suitably set in the range which does not impair the object of the present invention.

  The step (a1) and the step (a2) are collectively described as a step (a).

  In the step (a), the compounding amount of the organic peroxide is preferably 0.003 to 0.3 parts by mass, and 0.005 to 0.3 parts by mass with respect to 100 parts by mass in total of the base resin and the carrier resin. A part is more preferable and 0.005-0.1 mass part is still more preferable. By setting the compounding amount of the organic peroxide in the above range, the grafting reaction can be carried out in an appropriate range, and generation of bumps is suppressed to prepare a silane graft resin composition excellent in extrudability. it can.

  In a process (a2), 10-400 mass parts is preferable with respect to the said total of 100 mass parts, and, as for the compounding quantity of an inorganic filler, 30-280 mass parts is more preferable. By making the compounding quantity of an inorganic filler into the said range, high heat resistance and the outstanding appearance can be provided to a silane crosslinked resin molded object.

  In the step (a), the compounding amount of the silane coupling agent is more than 2.0 parts by mass, preferably 15.0 parts by mass or less, more preferably 3 to 12.0 parts by mass, in the total 100 parts by mass. Further preferred is 12.0 parts by mass. By making the compounding quantity of a silane coupling agent into the said range, high heat resistance and the outstanding external appearance can be provided to a silane crosslinked resin molded object.

In the present invention, “a resin for forming a silane graft resin, an organic peroxide, and a silane coupling agent are melt mixed” (step (a1)), “a resin for forming a silane graft resin, and an organic peroxide, And “inorganic filler and the silane coupling agent are melt mixed” (step (a2)) does not specify the order of mixing at the time of melt mixing, and any mixing may be performed. It means good.
In the step (a2), it is preferable to melt and mix the above-described components in the following steps (a2-1) and (a2-2).
Step (a2-1): Step of mixing a mixture by mixing at least an inorganic filler and a silane coupling agent having a grafting reaction site Step (a2-2): the mixture obtained in step (a2-1) and silane The resin for graft resin formation is melted and mixed in the presence of the organic peroxide at a temperature higher than the decomposition temperature of the organic peroxide, and the resin generated from the organic peroxide is a resin for silane graft resin formation. A step of obtaining a silane graft resin composition containing a base resin containing a silane graft resin by grafting a silane coupling agent

The method of mixing the inorganic filler and the silane coupling agent in the step (a2-1) is not particularly limited, and wet mixing or dry mixing may be used. In the present invention, dry blending (dry blending) in which a silane coupling agent is mixed with an inorganic filler with or without heating is preferred. The silane coupling agent thus premixed is present to surround the surface of the inorganic filler, and a part or all of the silane coupling agent is adsorbed or bonded to the inorganic filler. This can reduce the volatilization of the silane coupling agent during the subsequent melt mixing. The dry mixing is performed at a temperature lower than the decomposition temperature of the organic peroxide, and the above components are mixed while suppressing the occurrence of the grafting reaction. The mixing temperature is preferably 10 to 50 ° C., more preferably room temperature (25 ° C.) to 40 ° C., and the inorganic filler and the silane coupling agent can be set to conditions of several minutes to several hours.
The organic peroxide may be present in the step (a2-2), and may be mixed in the step (a2-1) or may be mixed in the step (a2-2).

  Next, the mixture obtained in step (a2-1) and the resin for forming a silane graft resin are melt mixed (step (a2-2)). In this way, the grafting reaction site of the silane coupling agent and the graftable reaction site of the resin for forming a silane graft resin are caused to undergo a grafting (bonding) reaction by radicals generated from the organic peroxide.

  In melt mixing of each of the step (a1), the step (a2) and the step (a2-2), the temperature for melting and mixing the above components is a temperature equal to or higher than the decomposition temperature of the organic peroxide, preferably 150 to 230 ° C. . Other mixing conditions, for example, mixing time can be set appropriately. As a result, the organic peroxide is decomposed on the melted component, and the generated radicals act to cause the grafting reaction site of the silane coupling agent and the graftable reaction site of the resin for forming the silane graft resin. The grafting reaction (coupling) proceeds. The melt mixing method is not particularly limited, and the mixing may be carried out in the same manner as the above-mentioned step (b).

  In the step (a), the resin other than the silane graft resin, the mineral oil and the additive may be mixed in any of the above steps.

Thus, the step (a) can be carried out to prepare a silane graft resin composition containing a silane graft resin.
The step (a) can be carried out simultaneously or continuously with the melt mixing of the step (b).

Step (a) is preferably performed in the absence of a silanol condensation catalyst to suppress the condensation reaction of the silane coupling agent. In the present invention, to melt and knead in the absence of a silanol condensation catalyst means to melt and knead substantially without blending the silanol condensation catalyst. That is, it does not exclude the silanol condensation catalyst which is inevitably present, and means that it may be present as long as the problems of the following kneadability and formability by the silanol condensation of the silane coupling agent do not occur. Do. For example, the silanol condensation catalyst may be present as long as it is 0.01 parts by mass or less with respect to 100 parts by mass of the resin composition. By performing the melt-kneading in the absence of the silanol condensation catalyst, the condensation reaction of the silane coupling agent can be suppressed, the kneadability is excellent (easy to melt and knead), and the formability is excellent (desired shape Can be extruded into
Thus, a silane graft resin composition is synthesized by causing the resin for forming a silane graft resin and the silane coupling agent to undergo a grafting reaction, whereby a silane graft resin composition containing this silane graft resin as a reaction composition is prepared. Ru. In this grafting reaction, usually, one molecule of silane coupling agent is added to one graftable site, but the present invention is not limited thereto. This silane graft resin composition is a reaction composition containing a silane graft resin in which a silane coupling agent is grafted to a base resin to such an extent that molding is possible by the above-mentioned step (b).

  In the step (a2-2), at least the following may be mentioned as an embodiment in which the silane coupling agent grafts to the resin for forming a silane graft resin. The silane coupling agent bound or adsorbed to the inorganic filler in a weak bond in the step (a2-1) is released from the inorganic filler, and undergoes a grafting reaction on the resin for forming a silane graft resin in the step (a2-2). In addition, the silane coupling agent bonded or adsorbed to the inorganic filler by a strong bond undergoes a grafting reaction on the resin for forming a silane graft resin while maintaining the bond with the inorganic filler.

As described above, a silane cross-linked resin molded product is produced. The silane cross-linked resin molded product contains a cross-linked resin obtained by cross-linking the above-mentioned silane graft resin.
One form of the silane cross-linked resin molded product produced through the above step (a1) is a cross-linking reaction between the silane coupling agents which have been grafted to the resin for forming a silane graft resin (silanol condensation reaction between hydrolyzable silyl groups) Containing a crosslinked product of a silane graft resin bonded (crosslinked) via at least two silane coupling agents.
One form of the silane-crosslinked resin molded article produced through the above step (a2) is considered to contain the following cross-linked silane graft resin. A crosslinked product of a silane graft resin bonded (crosslinked) via a silane coupling agent is contained by crosslinking reaction of the silane coupling agent which has been desorbed from the inorganic filler and grafted to the resin for forming a silane graft resin. In addition to this, the silane coupling agent that has been grafted to the resin for forming a silane graft resin in a state that holds a bond with the inorganic filler is unlikely to cause a crosslinking reaction, and bonds with the inorganic filler via the silane coupling agent (crosslinking) Containing a crosslinked product of the silane graft resin. The silane-crosslinked resin molded product containing the cross-linked body of these resins exhibits excellent appearance and high heat resistance without losing high aging resistance, and further has high strength.

<Application of the manufacturing method of silane cross-linked resin molded product>
The method for producing a silane crosslinked resin molded article can be applied to the production of a product (including a semifinished product, a part, and a member) comprising the silane crosslinked resin molded article. This product may be a product containing a silane-crosslinked resin molded product or a product consisting only of a silane-crosslinked resin molded product. As such products, for example, covering materials of wiring materials such as heat-resistant wires, cables or optical fiber cables, rubber mold materials (for example, glass run channels for automobiles, weather strips, rubber hoses, wiper blade rubbers, anti-vibration rubbers), etc. may be mentioned. Be In addition, silane cross-linked resin molded articles can be used as a substitute for polyolefin materials that have been cross-linked or chemically vulcanized by electron beam irradiation, and EP rubber materials.
A product containing a silane cross-linked resin molded product can be produced by molding with other members using a silane cross-linking catalyst composition and a silane graft resin composition in a conventional manner.

[Wiring material]
The wiring material of the present invention has a coating layer made of a cured product of a silane crosslinkable resin composition. In other words, the wiring material of the present invention is a product including a silane-crosslinked resin molded product, and has a coating layer formed of the silane-crosslinked resin molded product. This coating layer is formed using the catalyst composition for silane crosslinking of the present invention, contains a crosslinked product of a silane graft resin as its base (matrix), and further contains an antioxidant at a high content. Therefore, the wiring material provided with this covering layer is excellent in heat resistance, aging resistance and appearance, and is not easily foamed at the time of secondary processing.
As the wiring material, a heat resistant wire, a cable, a cord, an optical fiber core wire or an optical fiber cord used for internal wiring or external wiring of electric / electronic equipment may be mentioned, and a heat resistant wire or cable is preferable.
The wiring material of the present invention is particularly required to have a high degree of aging resistance, such as wiring materials used around car engines, wiring materials for air conditioners, wiring materials for microwave ovens, etc. Can be preferably used as a wiring material used for a long time).

The wiring material of the present invention can be produced by a known method, and is suitably produced by the method for producing a silane-crosslinked resin molded article.
When the wiring material of the present invention is produced by extrusion molding using the catalyst composition for silane crosslinking of the present invention in the method of producing a silane crosslinked resin molded product, preferably, the catalyst composition for silane crosslinking of the present invention and silane grafting A molding material mixed with a resin composition is melt mixed in an extruder (extrusion coating apparatus) and extruded around the periphery of a conductor or the like, and then brought into contact with water to provide a coating layer composed of a silane crosslinked resin molding Wiring material can be manufactured.
The conductor to be used may be a single wire or a stranded wire, or may be a bare wire or a tin-plated or enamel-coated one. As a metal material which forms a conductor, soft copper, a copper alloy, aluminum etc. are mentioned. The thickness of the insulating layer formed around the conductor is not particularly limited, but is usually about 0.15 to 5 mm.

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited thereto.
In Tables 1 to 3, numerical values relating to the compounding amount of each example represent parts by mass unless otherwise specified. Moreover, a blank for each component means that the compounding quantity of a corresponding component is 0 mass part.

The detail of each component (compound) shown in Table 1-Table 3 is shown below.
Hindered phenolic anti-aging agent: Irganox 1010 (trade name, pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], manufactured by BASF)
Hydrazine based heavy metal deactivator: Irganox MD 1024 (trade name, 1,2-bis [3- (4-hydroxy-3,5-di-tert-butylphenyl) propionyl] hydrazine, manufactured by BASF Corp.)
Benzimidazole anti-aging agent: Nocrac MBZ (trade name, 1,3-dihydro-2H-benzoimidazole-2-thione, 0.5 zinc salt, manufactured by Ouchi Shinko Chemical Co., Ltd.)

Silanol condensation catalyst: Adekastab OT-1 (trade name, dioctyl tin dilaurate, manufactured by Adeka)

HDPE: Hi-Zex 5305 E (trade name, high density polyethylene, MFR 0.8 g / 10 min, made by Prime Polymer Co.)
LLDPE: Evolue SP 0540 (trade name, linear low density polyethylene, MFR 3.8 g / 10 min, made by Prime Polymer Co.)
PP: PB222A (trade name, polypropylene, MFR 0.7 g / 10 min (230 ° C., 2.16 kg), manufactured by Sun Aroma Co., Ltd.)
EVA: Evaflex EV 360 (trade name, ethylene-vinyl acetate copolymer, MFR 2 g / 10 min, Mitsui-Dupont Polychemicals Co., Ltd.)
EEA: NUC 6510 (trade name, ethylene-ethyl acrylate copolymer resin, MFR 0.5 g / 10 min, manufactured by NUC)
EPDM: Nordel 3720P (trade name, ethylene-α-olefin copolymer rubber, MFR 0.7 g / 10 min, manufactured by Dow)
Ethylene acrylic rubber: Baymac DP (trade name, MFR 0.7 g / 10 min or less, manufactured by DuPont)
SEPS: Septon 4077 (trade name, manufactured by Kuraray)
OIL: Diana Process PW90 (trade name, paraffinic oil, dynamic viscosity 96 cSt at 40 ° C, pour point 15 ° C, flash point (COC) 250 ° C or higher, Idemitsu Kosan Co., Ltd.)
Silane-grafted LLDPE: Lyndron XCF 730 M (trade name, manufactured by Mitsubishi Chemical Corporation)

(Examples 1 to 20 and Comparative Examples 1 to 8)
First, after melt-mixing each component shown in the "catalyst master batch" column of Tables 1-3 at 200 degreeC using the Banbury mixer, it pelletized and obtained the pellet of the catalyst master batch. The catalyst masterbatch contained a benzimidazole antioxidant, a hydrazine heavy metal deactivator, and a hindered phenolic antioxidant in the amounts described in Tables 1 to 3.
Moreover, about Example 19 and 20, after melt-mixing each component shown in the "silane master batch" column at 200 degreeC using the Banbury mixer, it pelletized and obtained the pellet of the silane master batch.

Moreover, each component shown in the "silane master batch" column of Tables 1-3 or the silane master batch prepared above and the catalyst master batch prepared above were dry-blended to obtain a dry blend. The mixing ratio at this time is the mixing ratio shown in the "silane masterbatch" column for the silane graft resin, and the mass shown in the "catalyst masterbatch mixed with the silane masterbatch" column in Tables 1 to 3 for the catalyst masterbatch. The ratio (the total of the base resin and the carrier resin is 100 parts by mass).
Each mixing ratio described in the column of "the catalyst masterbatch mixed with the silane masterbatch" in Tables 1 to 3 corresponds to the mixing ratio with respect to 100 parts by mass of the total amount of the base resin and the carrier resin.

Next, a 25 mm diameter extruder (ratio of screw effective length L to diameter D: L / D = 25) was added to the die temperature of 160 ° C., to the feeder side, C3 = 150 ° C., C2 = 140 ° C., C1 = 130 ° C. The extrusion temperature conditions of were set. The dry blend prepared in this extruder is charged and melt mixed to prepare a melt mixture (silane crosslinkable resin composition), and this melt mixture is placed on a 0.8 mm diameter conductor made of bare soft copper wire and has an outer diameter It extrusion-coated so that it might be set to 1.2 mm diameter and 0.2 mm in thickness.
The obtained coated conductor (crosslinkable resin molded body) was left in an environment of 23 ° C. and 50% relative humidity for 24 hours to be in contact with water. Thus, a wire having a coating layer comprising a cured product of the silane crosslinkable resin composition was produced.

  The following tests were conducted for each pellet obtained in the same manner as the extrusion coating, each coated conductor obtained above, or each manufactured electric wire, and the results are shown in Tables 1 to 3.

[Bubble test 1 (foaming suppression evaluation at the time of catalyst MB preparation)]
The central portion of 10 randomly selected particles of the catalyst masterbatch pellets obtained above was cut (cut at the center of the long axis and perpendicular to the long axis), and the cut surface was visually observed. As a result, those which did not see foaming on the cut surface of all the pellets (pass) were represented as "○", and those where even one foam was viewed (not acceptable) were represented as "x".
Here, the fact that foaming is not observed means a case where air bubbles (voids) having a size of 0.05 mm or more are not observed in the cut surface.

[Bubbling test 2 (foaming suppression evaluation at the time of secondary processing)]
As a foaming test of the electric wire, a solder heat resistance test was conducted on the assumption of the presence or absence of foaming at the time of secondary processing. Specifically, the coating layer of the electric wire was peeled 5 mm from the tip, and the portion of the conductor 3 mm in length from the tip of the conductor exposed by peeling the coating layer was dipped and held in a solder bath set at 330 ° C. Thereafter, the electric wire was pulled up from the solder bath, and the presence or absence of foaming in a cross section perpendicular to the length direction of the conductor of a portion 5 mm long from the tip of the exposed conductor of the coating layer of the electric wire was confirmed. Observation of foaming was performed using a microscope. Here, the fact that foaming is not observed means a case where air bubbles (voids) having a size of 0.01 mm or more are not observed in the cross section.
In the said immersion, the presence or absence of foaming was evaluated by the following evaluation criteria by the longest immersion time in which foaming is not observed in a coating layer cross section.
The case where the longest immersion time is 10 seconds or more is described as "◎", the case where it is less than 5 to 10 seconds is described as "○", and the case where it is less than 1 to 5 is "△" In the case where it is less than 1 second (rejected) is indicated by "x".

[Aging resistance]
The conductor was removed from the wire to make a tubular piece, and a tensile test was performed. The test was conducted at 25 mm between marked lines and at a tensile speed of 50 mm / min to measure the tensile strength and the elongation at break. The tensile test was conducted at normal temperature (25 ° C.) and normal humidity (relative humidity: 50%) according to UL758.
On the other hand, each wire was heated at 180 ° C. for 2, 4, 7 or 10 days in a thermostat. The tensile strength and the elongation at break were measured in the same manner as described above using a tubular piece obtained by removing the conductor from the heat-treated wire. For each of the measured tensile strength and the elongation at break, the ratio to the tensile strength and the elongation at break (tensile strength retention and elongation retention at break) of the wire before heat treatment was determined.
The residual tensile strength and tensile elongation obtained were evaluated according to the following.
The tensile strength after 10 days and the residual ratio of tensile elongation are both 80% or more: ◎
After 10 days, either tensile strength or tensile elongation residual rate is less than 80%, but after 7 days, both of these residual rates are 80% or more: ○
After 7 days, either tensile strength or tensile elongation residual ratio is less than 80%, but after 4 days, both of these residual ratios are 80% or higher: ○ △
After 4 days, either tensile strength or tensile elongation residual ratio is less than 80%, but after 2 days, both of these residual ratios are 80% or more: Δ
Either of the tensile strength and the tensile elongation residual ratio after 2 days is 80% or less (failed): x

[Formability]
The moldability (extrusion moldability) of the silane crosslinkable resin composition was evaluated using the dry blend prepared in each of the above examples.
The dry blend prepared in each example was extrusion coated in the same manner as the extrusion coating except that the linear velocity was changed to obtain a wire.
In this extrusion coating, the formability was evaluated by the following evaluation criteria by the maximum production speed (maximum linear velocity) which can be extrusion-coated. Here, the maximum production speed that can be extrusion-coated is the highest in linear speed without appearance defects in the extrusion-coated coating layer and in which no bumps are observed.
The case where the maximum linear velocity is 150 mm / min or more is indicated by “◎”, and the case where it is 100 mm / min or more and less than 150 mm / min is indicated by “○”, 40 mm / min or more and less than 100 mm / min The case where it exists was described by "(triangle | delta)", and when it was less than 40 mm / min (rejected) was described by "x".
Here, the appearance defect means foaming and unevenness, such as so-called melt fracture, on the surface of a molded product, or roughness. About foaming, the presence or absence of foaming in the external appearance of the coating layer of the electric wire was confirmed. The observation of foaming was performed visually. Here, the fact that foaming is not observed means that bubbles of a size of 0.05 mm or more are not observed on the surface. The term "butsu" refers to agglomerates formed by cross-linking, which are agglomerated without being compatible with each other.

[Heating deformation test (heat resistance)]
The heat distortion characteristics of the coating layer were measured for each wire. By this test, the degree of crosslinking reaction (heat resistance of the silane-crosslinked resin molded product) can be evaluated.
The heat deformation test was performed according to UL758. At a measurement temperature of 121 ° C., a load of 2.45 N was applied to each wire in the direction perpendicular to the longitudinal direction. At this time, the rate of deformation of the coating layer ([(thickness of coating layer before heating−thickness of coating layer after heating) / thickness of coating layer before heating] × 100) is less than 30% "○", those with 30% or more and less than 50% were made "Δ", and those with 50% or more (failed) were made "×".

From the results of Tables 1 to 3, the following can be understood.
Comparative Example 1 using a catalyst masterbatch containing too much content of hydrazine heavy metal deactivator even if the content of benzimidazole type antioxidant is within the range specified in the present invention is a preparation of a catalyst masterbatch Foaming was observed in the foam inhibition test during time and secondary processing. Moreover, the maximum production speed which can be extrusion-molded was slow, and the silane crosslinking resin composition was inferior to the moldability.
In Comparative Example 2 in which the catalyst masterbatch containing too much content of the benzimidazole based antioxidant was used, foaming was observed at the time of preparation of the catalyst masterbatch, and the moldability of the silane crosslinkable resin composition was inferior.
The comparative example 3 using the catalyst masterbatch in which the content of the benzimidazole based antioxidant was too low was inferior in aging resistance.
Comparative Example 4 using a catalyst masterbatch in which the MFR is too high even if the contents of the benzimidazole based antioxidant and the hydrazine based heavy metal deactivator satisfy the range specified in the present invention is the time of preparation of the catalyst masterbatch And foaming was seen in the foaming suppression test at the time of secondary processing. On the other hand, Comparative Example 5 using a catalyst master batch in which the MFR is too low even if the contents of the benzimidazole based antioxidant and the hydrazine based heavy metal deactivator satisfy the range specified in the present invention is a silane crosslinkable resin The moldability of the composition was not sufficient.
The comparative example 6 using the catalyst masterbatch in which the content of the silanol condensation catalyst is too small even though the antioxidant and MFR satisfy the range specified in the present invention was inferior in the heat resistance of the obtained electric wire. On the other hand, in Comparative Example 7 using the catalyst master batch in which the content of the silanol condensation catalyst is too large even though the range defined in the present invention is satisfied, the silane crosslinkable resin composition did not exhibit sufficient moldability.
The comparative example 8 using the catalyst masterbatch with too much content of a benzimidazole type anti-aging agent showed the appearance defect by foaming.

On the other hand, all of the catalyst masterbatches of Examples 1 to 20, which contain specific amounts of benzimidazole based antioxidant, hydrazine based heavy metal deactivator and silanol condensation catalyst and MFR in a specific range, are pellets. Foaming during preparation is suppressed. Moreover, the electric wire of Examples 1-20 which used the catalyst masterbatch of this invention in combination with the silane graft resin in a specific ratio has an excellent appearance, heat resistance, and aging resistance, and suppresses foaming at the time of secondary processing. Foaming is suppressed in the test. Thus, the catalyst masterbatch of Examples 1-20 can manufacture the electric wire excellent in an external appearance, heat resistance, and aging resistance by using for the silane crosslinking method. Moreover, the silane crosslinkable resin composition using these catalyst masterbatch has shown the outstanding moldability which can shape | mold the crosslinked body of silane crosslinked resin, suppressing appearance defect and generation | occurrence | production of a bump.
As described above, the catalyst masterbatch of the present invention can impart excellent heat resistance, aging resistance and appearance while reducing foaming, even if it contains a relatively large amount of benzimidazole based antioxidant. .

Claims (9)

What is claimed is: 1. A catalyst composition for silane crosslinking, which is used for crosslinking of a silane graft resin grafted with a silane coupling agent having a hydrolyzable silyl group,
Containing 15 to 50 parts by mass of benzimidazole based antioxidant, 25 parts by mass or less of hydrazine based heavy metal deactivator, and 0.05 to 5 parts by mass of silanol condensation catalyst with respect to 100 parts by mass of carrier resin containing polyolefin resin And a catalyst composition for silane crosslinking having a melt flow rate of 0.1 to 15 g / 10 min at 190 ° C. and 2.16 kg.   The catalyst composition for silane crosslinking according to claim 1, containing 30 parts by mass or less of a phenolic antioxidant.   The silane crosslinking catalyst composition according to claim 1 or 2, wherein the melt flow rate at 190 ° C and 2.16 kg is 0.5 to 10 g / 10 min.   The catalyst composition for silane crosslinking according to any one of claims 1 to 3, wherein the carrier resin contains 20% by mass or more of a styrene-based elastomer.   It is a molten mixture of the catalyst composition for silane crosslinking according to any one of claims 1 to 4 and a silane graft resin composition containing a base resin, and the base resin has a hydrolyzable silyl group. Silane crosslinkable resin composition containing the silane grafting resin which the silane coupling agent grafted.   The silane crosslinkable resin composition according to claim 5, wherein the base resin contains 10% by mass or more of a styrene-based elastomer.   The silane crosslinking resin composition of Claim 5 or 6 which contains an inorganic filler 10-400 mass parts with respect to a total of 100 mass parts of the carrier resin of the catalyst composition for silane crosslinking, and the said base resin.   The wiring material which has a coating layer which consists of hardened | cured material of the silane crosslinking resin composition of any one of Claims 5-7. The wiring material according to claim 8, which is a heat-resistant wire or a cable.