JP6523513B2 - Crosslinked resin molded article and crosslinkable resin composition, method for producing them, silane master batch, and molded article - Google Patents

Description

  The present invention relates to a crosslinked resin molded article, a crosslinkable resin composition, a method for producing them, a silane master batch, and a molded article. More specifically, a crosslinked resin molded article having excellent appearance and mechanical properties while maintaining high heat resistance, and more preferably capable of reducing the weight and a method for producing the same, a silane master batch capable of forming the crosslinked resin molded article, crosslinkability The present invention relates to a resin composition and a method for producing the same, and a molded article such as an electric wire, a rubber grommet, a rubber hose, or a vibration-proof rubber using the crosslinked resin molded body as an insulator or a sheath.

Wires, rubber hoses (also referred to as rubber tubes), tires, rubber products such as grommets and antivibration rubbers are widely used as members requiring physical properties or characteristics such as flexibility, elasticity, resilience, and permanent compressibility. ing.
A wide range of rubber materials such as ethylene-propylene-diene rubber (EPDM), styrene butylene rubber (SBR), nitrile butylene rubber (NBR) and fluororubber are used as rubber materials for forming these rubber products.
In addition, cross-linked polyethylene materials are widely used as coating materials and members for various cables, taking advantage of their heat resistance.

These rubber materials and crosslinked polyethylene are manufactured into rubber products as follows. That is, a crosslinking agent such as an organic peroxide or a phenol compound is blended in the rubber in advance, and molding is performed in a state where these crosslinking agents do not react sufficiently. Thereafter, the uncrosslinked molded product is crosslinked by heating and cooled to obtain a crosslinked molded product having rubber elasticity and flexibility.
For example, in the case of continuous production of electric wires, rubber materials and the like are molded at a low temperature of 120 ° C. or lower, and in that state, they are crosslinked through a vulcanizing tube warmed with, for example, steam, and further cooled with water or the like. Through a cooling pipe.
Thus, when using the above-mentioned rubber material or crosslinked polyethylene, when molding these rubber materials etc., molding is carried out at a temperature at which the crosslinking agent does not react, and then the crosslinking agent is decomposed and reacted while maintaining the molded state Sufficient heating at temperature is required to proceed the crosslinking and to cool it. Therefore, a long time is required for manufacturing time.
In addition, generally, it is necessary to mold the rubber material or the like at a temperature at which the crosslinking agent does not react, and there is a problem that it is difficult to mold by a specific method such as injection molding.

As a method of solving these problems, vinyl aromatic heats, which use thermoplastic elastomers and block copolymers shown in Patent Documents 1 to 3 as base resins, and a softener for non-aromatic rubber as a softener are added A method has been proposed for dynamic crosslinking of plasticized elastomeric compositions with organic peroxides via silane surface-treated metal hydrates.
However, although these thermoplastic elastomers have flexibility, they melt at high temperatures and can not be used as rubber products.

By the way, as a method of crosslinking polyolefin resin such as polyethylene, an electron beam crosslinking method using an electron beam, a silane crosslinking method and the like can be mentioned.
However, the electron beam crosslinking method is not only extremely expensive in equipment cost, but also limited in the thickness of a molded product that can be produced, and can not be used for various rubber products.
On the other hand, in the silane crosslinking method, a crosslinked product is obtained by causing a silane grafting reaction of a silane coupling agent in the presence of an organic peroxide to obtain a silane graft polymer, and then bringing it into contact with moisture in the presence of a silanol condensation catalyst. It is a way to get. This silane crosslinking method often does not require special equipment.
Therefore, among the above crosslinking methods, in particular, the silane crosslinking method is used in a wide range of fields.

Generally, when mixing filler with resin, a Banbury mixer, a kneader mixer or a twin screw extruder is used.
However, when a resin containing a filler is crosslinked by a silane crosslinking method, if a kneader or a Banbury mixer is used, the silane coupling agent has high volatility and volatilizes before the silane grafting reaction. Therefore, it becomes difficult to prepare a silane masterbatch containing a silane graft polymer and a filler. In addition, even in the case of using a twin-screw extruder, there is a problem that resin pressure control is difficult and foaming is likely to occur.

  Therefore, when producing a silane master batch with a Banbury mixer or a kneader, a silane coupling agent is added to a master batch obtained by melting and mixing polyolefin and a filler such as a flame retardant or reinforcing material, and the silane is added to the polyolefin with a single screw extruder. A method is conceivable in which a coupling agent is subjected to a silane grafting reaction. However, this method may cause appearance defects. Moreover, when an anti-aging agent is contained in a masterbatch, inhibition of a silane grafting reaction may occur and desired heat resistance may not be obtained.

As another method, in Patent Document 4, an inorganic resin surface-treated with an olefin resin with a silane coupling agent, a silane coupling agent, an organic peroxide, and a crosslinking catalyst are melt-kneaded with a kneader, and a single screw extruder is used. Methods of forming are described.
However, in this method, during melt-kneading in a kneader, olefin resins cross-link with each other to cause appearance defects. In addition, most of silane coupling agents other than the silane coupling agent which surface-treated the inorganic filler volatilize, or silane coupling agents will condense. Therefore, not only the desired heat resistance can not be obtained, but also the condensation of the silane coupling agents may cause the appearance deterioration.

  In any of the above methods, it is necessary to blend a large amount of filler and the like in order to exert desired properties such as mechanical properties, abrasion resistance and flame retardancy to the rubber product.

Unexamined-Japanese-Patent No. 2000-143935 JP, 2000-315424, A JP 2001-240719 A JP 2001-101928 A

The present invention solves the above problems and is produced by suppressing volatilization of a silane coupling agent, which is excellent in appearance and mechanical properties while maintaining high heat resistance, and more preferably can be reduced in weight. And providing a method of manufacturing the same.
Another object of the present invention is to provide a silane masterbatch, a crosslinkable resin composition, and a method for producing the same, which can form the crosslinked resin molded article.
Furthermore, this invention makes it a subject to provide the molded article containing a crosslinked resin molded object.

  The present inventors have made the silane coupling agent and the silica satisfy the specific value of X value defined by the following formula (I) when graft reacting a silane coupling agent to a polyolefin resin in the presence of silica. It has been found that when used in combination, it is possible to prevent volatilization of the silane coupling agent, to produce a crosslinked resin molded article having heat resistance, appearance and mechanical properties in a well-balanced manner, and also possible to reduce the weight. The present inventors have further researched on the basis of these findings and made the present invention.

That is, the object of the present invention is achieved by the following means.
It is a manufacturing method of the crosslinked resin molded object which has <1> following process (1), process (2), and process (3) ,
Process (1): Polyole containing 25% by mass or more of ethylene-propylene-diene rubber
Organic peroxide 0.02 to 0.6 quality per 100 parts by mass of fin-based resin
Parts, 0.1 to 140 parts by mass of silica, and an ethylenically unsaturated group
2 to 15.0 parts by mass of a silane coupling agent containing
The silane coupling agent and the polyolefin are mixed with a cocatalyst.
By including a resin with a resin, a bridge containing a silane crosslinkable resin is obtained.
Step to obtain a bridge resin composition (2): to obtain a molded body by molding the said crosslinkable resin composition obtained in step (1)
Step (3): The molded product obtained in the step (2) is brought into contact with water to obtain a crosslinked resin molded product
Process

The manufacturing method of the crosslinked resin molding whose said process (1) has following process (a)-process (d) .
Process (a): The organic peroxide and the X value defined by the following formula (I) are 33.3 to 10
Mixing the silica satisfying 00 and the silane coupling agent
Formula (I) X = ΣA / B
(Wherein ΣA is the BET specific surface area (m ² / g) of silica and the blending amount of silica
And B represents the compounding amount of the silane coupling agent. )
Step (b): The mixture obtained in the step (a) and all of the polyolefin resin
Partially melt-mix at a temperature above the decomposition temperature of the organic peroxide ,
Grafting reaction between the silane coupling agent and the polyolefin resin
To obtain a silane masterbatch containing a silane crosslinkable resin
Process step (c): the above-mentioned polyolefin-based resin as the silanol condensation catalyst and carrier resin
Process of mixing the resin different from fat or the remaining part of the polyolefin-based resin Process (d): Silane master batch obtained in the process (b), and the process (c)
Step of obtaining a crosslinkable resin composition by mixing the obtained mixture <2> The silane coupling agent is more than 4 parts by mass and 15.0 parts by mass or less with respect to 100 parts by mass of the polyolefin resin The manufacturing method of the crosslinked resin molded object as described in <1> mixed by the compounding quantity of these.
The manufacturing method of the crosslinked resin molded object as described in <1> or <2> whose <3> above-mentioned silica is crystalline silica.
The manufacturing method of the crosslinked resin molded object as described in any one of <1>-<3> whose <4> silane coupling agent is vinyl trimethoxysilane or vinyl triethoxysilane.

Organic peroxide 0.02 to 0.6 parts by mass and silica 0.1 to 140 parts by mass with respect to 100 parts by mass of a polyolefin resin containing 25 mass% or more of a <5> ethylene-propylene-diene rubber, By mixing 2 to 15.0 parts by mass of a silane coupling agent containing a group containing an ethylenically unsaturated group with a silanol condensation catalyst, and causing the silane coupling agent and the polyolefin resin to undergo a grafting reaction , a crosslinkable resin composition comprising a silane-crosslinkable resin having obtained Ru process, a process for the preparation of a crosslinkable resin composition,
The manufacturing method of the crosslinkable resin composition whose process to mix has a following process (a)-process (d) .
Process (a): The organic peroxide and the X value defined by the following formula (I) are 33.3 to 10
Mixing the silica satisfying 00 and the silane coupling agent
Formula (I) X = ΣA / B
(Wherein ΣA is the BET specific surface area (m ² / g) of silica and the blending amount of silica
And B represents the compounding amount of the silane coupling agent. )
Step (b): The mixture obtained in the step (a) and all of the polyolefin resin
Partially melt-mix at a temperature above the decomposition temperature of the organic peroxide ,
Grafting reaction between the silane coupling agent and the polyolefin resin
To obtain a silane masterbatch containing a silane crosslinkable resin
Process step (c): the above-mentioned polyolefin-based resin as the silanol condensation catalyst and carrier resin
Process of mixing the resin different from fat or the remaining part of the polyolefin-based resin Process (d): Silane master batch obtained in the process (b), and the process (c)
Step of obtaining a crosslinkable resin composition by mixing the obtained mixture <6> A crosslinkable resin composition produced by the method for producing a crosslinkable resin composition according to <5>.
The crosslinked resin molded object manufactured with the manufacturing method of the crosslinked resin molded object of any one of <7> said <1>-<4>.
The molded article containing the crosslinked resin molded object as described in <8> said <7>.
0.02 to 0.6 parts by mass of an organic peroxide, 0.1 to 140 parts by mass of silica, and 100 parts by mass of a polyolefin resin containing 25% by mass or more of a <9> ethylene-propylene-diene rubber, By mixing 2 to 15.0 parts by mass of a silane coupling agent containing a group containing an ethylenically unsaturated group with a silanol condensation catalyst, and causing the silane coupling agent and the polyolefin resin to undergo a grafting reaction It is a silane masterbatch used for the production of the crosslinkable resin composition obtained ,
The silane masterbatch obtained by the following process (a) and process (b) .
Process (a): The organic peroxide and the X value defined by the following formula (I) are 33.3 to 10
Mixing the silica satisfying 00 and the silane coupling agent
Formula (I) X = ΣA / B
(Wherein ΣA is the BET specific surface area (m ² / g) of silica and the blending amount of silica
And B represents the compounding amount of the silane coupling agent. )
Step (b): The mixture obtained in the step (a) and all of the polyolefin resin
Partially melt-mix at a temperature above the decomposition temperature of the organic peroxide ,
Grafting reaction between the silane coupling agent and the polyolefin resin
Step of

  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.

According to the present invention, volatilization of the silane coupling agent at the time of kneading can be suppressed by mixing the silica and the silane coupling agent before and / or at the time of kneading with the polyolefin resin, and the method can be simplified. Crosslinked resin moldings can be produced efficiently. Moreover, by using a specific silica in combination with a silane coupling agent, it is possible to overcome the problems of the conventional silane crosslinking method and to produce a crosslinked resin molded article excellent in heat resistance, appearance and mechanical properties. Furthermore, a lightweight crosslinked resin molded product can be produced.
Therefore, according to the present invention, it is possible to provide a crosslinked resin molded article which is excellent in appearance and mechanical properties while maintaining high heat resistance, more preferably reduced in weight, which can be produced by suppressing volatilization of a silane coupling agent. .
Moreover, the present invention can provide a silane masterbatch, a crosslinkable resin composition, and a method for producing the same, which can form a crosslinked resin molded article excellent in such properties.
Furthermore, it is possible to provide a molded article comprising the crosslinked resin molded article excellent in the above-mentioned properties.

  Hereinafter, preferred embodiments of the present invention will be described in detail.

All of the “method for producing a crosslinked resin molded product” of the present invention and the “method for producing a crosslinkable resin composition” of the present invention at least perform the following step (1). Moreover, the "silane masterbatch" of this invention is manufactured by the following process (a) and process (b).
Therefore, the "method for producing a cross-linked resin molded product" of the present invention and the "method for producing a cross-linkable resin composition" of the present invention ), Will be described below. Further, in the method for producing the "silane master batch" of the present invention, the common parts to the method of the present invention will be described together.

Step (1): 0.02 to 0.6 parts by mass of organic peroxide, 0.1 to 140 parts by mass of silica, and 2 to 15.0 parts of silane coupling agent based on 100 parts by mass of polyolefin resin Step of mixing a part and a silanol condensation catalyst to obtain a mixture step (2): forming the mixture obtained in the step (1) to obtain a formed body step (3): in the step (2) Step of contacting the obtained molded body with water to obtain a crosslinked resin molded body

A process (1) has the following process (a), a process (b), a process (c), and a process (d).
Step (a): Process formula (I) X = ΣA / B in which an organic peroxide, a silica satisfying an X value defined by the following formula (I) of 5 to 1000 and a silane coupling agent are mixed
(Wherein, ΣA represents the total amount of the BET specific surface area of the silica (m ² / g) × the blended amount of the silica, and B represents the blended amount of the silane coupling agent)
Step (b): a step of melting and mixing the mixture obtained in step (a) and all or part of the polyolefin resin at a temperature above the decomposition temperature of the organic peroxide step (c): silanol condensation catalyst and carrier resin Process of mixing the resin which is different from polyolefin resin and the remaining part of the above-mentioned polyolefin resin as a process (d): the process of mixing the fusion mixture obtained at process (b), and the mixture obtained at process (c)

First, each component used in the present invention will be described.
<Polyolefin resin>
The polyolefin-based resin used in the present invention is not particularly limited, and examples thereof include resins used for forming materials, rubber materials, cable materials and the like which form the above-mentioned rubber products. For example, each resin which consists of a polyethylene, a polypropylene, a polybutene, an ethylene-alpha-olefin copolymer, a copolymer which has an acid copolymerization component or an acid ester copolymerization component, a rubber | gum, an elastomer, etc. which consist of these polymers are mentioned.
Among these, each resin such as polyethylene, polypropylene, ethylene-α-olefin copolymer, ethylene- (meth) alkyl ester copolymer or ethylene-vinyl acetate copolymer, or ethylene-propylene rubber, ethylene-propylene -Each rubber such as diene rubber or ethylene-butene rubber is preferable.
The polyolefin resins may be used alone or in combination of two or more.
When the polyolefin resin contains a plurality of components, the content of each component is appropriately adjusted so that the total of each component is 100% by mass, and preferably selected from the following range.

The polyethylene is not particularly limited, and, for example, homopolymers consisting only of ethylene, high density polyethylene (HDPE), low density polyethylene (LDPE), ultrahigh molecular weight polyethylene (UHMW-PE), linear low density polyethylene ( LLDPE), very low density polyethylene (VLDPE). Among them, linear low density polyethylene and low density polyethylene are preferable.
It is preferable that it is 0-95 mass% in polyolefin resin, and, as for the compounding quantity of polyethylene, it is more preferable that it is 0-60 mass%.

Polypropylene includes homopolymers of propylene, ethylene-propylene copolymers such as random polypropylene and block polypropylene.
It is preferable that it is 0-50 mass% in polyolefin resin, and, as for the compounding quantity of a polypropylene, it is more preferable that it is 0-30 mass%.

It does not specifically limit as an ethylene-alpha-olefin copolymer, Preferably, the copolymer of ethylene and a C3-C12 alpha-olefin is mentioned. It does not specifically limit as a specific example of (alpha) -olefin, For example, propylene, 1-butene, 1-hexene, 4-methyl- 1-pentene, 1-octene, 1-decene, 1-dodecene etc. are mentioned. The ethylene-α-olefin copolymer is not particularly limited, and specifically, it is synthesized in the presence of an ethylene-propylene copolymer (EPR), an ethylene-butylene copolymer (EBR), and a single site catalyst And ethylene-.alpha.-olefin copolymers.
It is preferable that it is 0-95 mass% in polyolefin resin, and, as for the compounding quantity of ethylene-alpha-olefin copolymer, it is more preferable that it is 0-80 mass%.

It does not specifically limit as a copolymer which has an acid copolymerization component or an acid ester copolymerization component, For example, ethylene-vinyl acetate copolymer, ethylene- (meth) acrylic acid copolymer, ethylene- (meth) acrylics An acid alkyl copolymer etc. are mentioned. Among these, ethylene-vinyl acetate copolymer, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-butyl acrylate copolymer are preferable, and further, the receptivity to silica and flame retardant From the viewpoint of the properties, ethylene-vinyl acetate copolymer is preferred.
The blending amount of the acid copolymerization component or the copolymer having the acid ester copolymerization component is preferably 0 to 80% by mass, and more preferably 0 to 50% by mass in the polyolefin resin.

In addition, as a polyolefin-based resin, a resin obtained by modifying the above-mentioned polymer or the like with an unsaturated carboxylic acid, for example, an acid anhydride such as maleic anhydride-modified polyethylene and its modified product (acid-modified resin) Can.
When using these as polyolefin resin, it is preferable that the compounding quantity in polyolefin resin is 0.5-30 mass parts.

The elastomer used in the present invention is not particularly limited. For example, styrene-butylene-styrene block copolymer (SBS), styrene-isoprene-styrene block copolymer (SIS), styrene-ethylene-propylene-styrene block copolymer Styrene elastomers, such as a polymer (SEPS), a styrene- ethylene- ethylene- propylene- styrene block copolymer (SEEPS), a styrene- ethylene- butylene- styrene block copolymer (SEBS), are mentioned.
The blending amount of the elastomer is preferably 0 to 95% by mass, and more preferably 0 to 80% by mass, in the polyolefin resin.

The rubber used in the present invention is not particularly limited, but ethylene rubber is preferable. The ethylene rubber is not particularly limited as long as it is a rubber (including an elastomer) composed of a copolymer obtained by copolymerizing a compound having an ethylenically unsaturated bond. More preferably, a copolymer of ethylene and an α-olefin, and a rubber composed of a ternary copolymer of ethylene, an α-olefin and a diene can be mentioned. As a rubber which consists of a copolymer of ethylene and an alpha olefin, ethylene propylene rubber, ethylene butene rubber, ethylene octene rubber etc. are mentioned, for example. Examples of the rubber composed of a terpolymer of ethylene, an α-olefin and a diene include ethylene-propylene-diene rubber and ethylene-butene-diene rubber.
It is preferable that it is 0-95 mass% in polyolefin resin, and, as for the compounding quantity of ethylene rubber, it is more preferable that it is 0-80 mass%.

In the present invention, the polyolefin resin may contain paraffin oil or naphthenic oil. In particular, it is preferable to use the above rubber (ethylene rubber) or styrenic elastomer in combination with paraffin oil or naphthenic oil. The oil is preferably paraffin oil in terms of mechanical strength.
The blending amount of the oil is preferably 0 to 60% by mass, and more preferably 0 to 40% by mass, in the polyolefin resin.
In the present invention, the oil is included in the polyolefin resin.

  The resin may contain, in addition to the components described above, additives described later, or resin components other than the above resin components.

<Organic peroxide>
The organic peroxide functions to generate a radical at least by thermal decomposition to cause a grafting reaction of the silane coupling agent to the polyolefin resin as a catalyst.
The organic peroxide used in the present invention is not particularly limited as long as it generates a radical, and, for example, general formulas: R ¹ -OO-R ² , R ¹ -OO-C (= O) R ³ The compound represented by R < ⁴ > C (= O) -OO (C = O) R < ⁵ > is preferable. Here, R ¹ , R ² , R ³ , R ⁴ and R ⁵ each independently represent an alkyl group, an aryl group or an acyl group. Among them, in the present invention, it is preferable that all of R ¹ , R ² , R ³ , R ⁴ and R ⁵ are alkyl groups, or one of them 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-butylperoxy Benzoate, tert-butyl peroxyisopropyl carbonate, diaceto Peroxide, lauroyl peroxide, may be mentioned tert- butyl cumyl peroxide and the like. Among them, 2,5-dimethyl-2,5-di- (tert-butylperoxy) hexane, 2,5-dimethyl-2,5-di- in view of odor, color and scorch stability. (Tert-butylperoxy) hexyne-3 is preferred.

The decomposition temperature of the organic peroxide is preferably 120 to 190 ° C., particularly preferably 125 to 180 ° C.
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./min in a nitrogen gas atmosphere by thermal analysis such as DSC method.

<Silica>
The silica used in the present invention is not particularly limited, and any of crystalline silica, non-crystalline silica, silica produced by a melting method, silica produced by a wet method, silica produced by a dry method, etc. Can also be used. As silica, crystalline silica is preferable. When a large amount of silica is used, crystalline silica prepared by a melting method is preferable. As the silica produced by the melting method, those commercially available from Ryumori Co., Ltd., Electric Chemical Industry Co., Ltd., etc. can be used. As silica manufactured by a wet process, what is marketed from Nippon Aerosil, Tosoh, etc. can be used.
The silica may be surface-treated with a silane coupling agent or other surface treatment agent, or may be untreated.

The BET specific surface area Yi (m ² / g) of the silica is not particularly limited as long as the X value defined by the formula (I) described later satisfies the following range. Without reducing the amount of the silane coupling agent that binds to the silica surface, in that it can reduce the amount of silica, BET specific surface area of silica is preferably ^{2~400m 2 / g, 2~350m 2 /} g is More preferably, 3 to 300 m ² / g, still more preferably 20 to 350 are more preferable.
The BET specific surface area Yi (m ² / g) of silica is a value measured using nitrogen gas as an adsorbate in accordance with the “carrier gas method” of JIS Z 8830: 2013. For example, it is a value measured using a specific surface area / pore distribution measuring apparatus “Flow Sorve” (manufactured by Shimadzu Corporation).

  The silica may be used alone or in combination of two or more.

<Inorganic fillers other than silica>
In the present invention, inorganic fillers other than silica can be used as long as the intended effects are not impaired. The inorganic filler other than silica is not particularly limited. For example, metal hydroxides such as aluminum hydroxide and magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide And metal hydrates such as metal compounds with hydroxyl group or water of crystallization such as aluminum oxide, aluminum nitride, aluminum borate whisker, hydrated aluminum silicate, hydrated magnesium silicate, basic magnesium carbonate, hydrotalcite etc. Be Besides, boron nitride, carbon, clay, zinc oxide, tin oxide, titanium oxide, molybdenum oxide, antimony trioxide, silicone compound, talc, zinc borate, white carbon, kaolin, zinc borate, zinc hydroxystannate, Zinc stannate is mentioned.
Among the inorganic fillers other than silica, at least one of aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, aluminum oxide (boehmite), kaolin, zinc borate, calcined clay and talc is preferable.
The BET specific surface area Yi (m ² / g) of the inorganic filler other than silica is not particularly limited. For example, 0.3 to ²⁰ m ² / g is preferable.
The inorganic fillers other than silica may be used singly or in combination of two or more.

The inorganic filler (including silica unless otherwise specified) may be surface-treated or non-treated.
Examples of the surface treatment agent include fatty acids such as stearic acid and oleic acid, silane coupling agents, phosphoric esters, titanate coupling agents, colloidal silica and the like.

  When the inorganic filler is a powder, the average particle diameter is preferably 0.1 to 20 μm, more preferably 0.5 to 5 μm, and still more preferably 0.6 to 2.5 μm. . When the average particle diameter of the inorganic filler is in the above range, heat resistance can be imparted to the crosslinked resin molded product. An average particle diameter says the average value calculated | required from the particle size of 100 inorganic fillers measured by TEM, SEM, etc.

<Silane coupling agent>
The silane coupling agent (also referred to as a hydrolyzable silanol compound) used in the present invention is not particularly limited, and examples thereof include silane coupling agents conventionally used in a silane crosslinking method. The silane coupling agent is preferably, for example, a compound represented by the following general formula (1).

In the general formula (1), R _a11 is a group containing an ethylenically unsaturated group, R _b11 is an aliphatic hydrocarbon group, a hydrogen atom or Y ¹³ . Y ¹¹ , Y ¹² and Y ¹³ are hydrolyzable organic groups. Y ¹¹ , Y ¹² and Y ¹³ may be the same or different.

In the general formula (1), R _a11 may include, for example, a vinyl group, a (meth) acryloyloxyalkylene group, a p-styryl group and the like, preferably a vinyl group.

R _b11 is an aliphatic hydrocarbon group, a hydrogen atom or Y ¹³ described later, and as the aliphatic hydrocarbon group, a monovalent aliphatic hydrocarbon group having 1 to 8 carbon atoms excluding an aliphatic unsaturated hydrocarbon group And preferably Y ¹³ described below.

Y ¹¹ , Y ¹² and Y ¹³ are hydrolyzable organic groups, and examples thereof include an alkoxy group, an aryloxy group and an acyloxy group, with an alkoxy group being preferable. As a hydrolyzable organic group, a methoxy, an ethoxy, butoxy, an acyloxy etc. can be mentioned, for example. Among these, methoxy or ethoxy is preferable in terms of reactivity.

The silane coupling agent is preferably a silane coupling agent having a high hydrolysis rate, more preferably a silane coupling agent in which R _b11 is Y ¹³ and Y ¹¹ , Y ¹² and Y ¹³ are the same as each other. is there. Specifically, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltributoxysilane, vinyldimethoxyethoxysilane, vinyldimethoxybutoxysilane, vinyldiethoxybutoxysilane, allyltrimethoxysilane, allyltriethoxysilane, vinyltriacetoxysilane And silane coupling agents having an ethylenically unsaturated group at the end such as methacryloxypropyltrimethoxysilane, methacryloxypropyltriethoxysilane, methacryloxypropylmethyldimethoxysilane and the like. These silane coupling agents may be used alone or in combination of two or more. Among such crosslinkable silane coupling agents, silane coupling agents having a vinyl group and an alkoxy group at the end are more preferable, and vinyltrimethoxysilane and vinyltriethoxysilane are particularly preferable.
The silane coupling agent may be used as it is or diluted with a solvent or the like.

<Silanol condensation catalyst>
The silanol condensation catalyst has a function of causing a condensation reaction of a silane coupling agent grafted on a polyolefin resin in the presence of water. Based on the function of the silanol condensation catalyst, the resin components are crosslinked via the silane coupling agent. As a result, a crosslinked resin molded product having excellent heat resistance is obtained.

  The silanol condensation catalyst is not particularly limited, and examples thereof include organic tin compounds, metal soaps, and platinum compounds. As a general silanol condensation catalyst, for example, dibutyltin dilaurate, dioctyltin dilaurate, dibutyltin diacrylate, dibutyltin diacetate, zinc stearate, lead stearate, barium stearate, calcium stearate, sodium stearate, Lead naphthenate, lead sulfate, zinc sulfate, organic platinum compounds and the like are used.

<Carrier resin>
It does not specifically limit as carrier resin used for this invention, The thing similar to the said polyolefin resin can be used. Preferably, it is polyethylene and polypropylene. The carrier resin may contain a resin component such as ethylene rubber or a styrene elastomer, or an oil.
When using a part of polyolefin resin in a process (a), carrier resin can use the remainder of polyolefin resin.
In the present invention, "a part of polyolefin resin" means a part of the resin used in the step (a) among the polyolefin resins. In part of this, a part of the polyolefin resin itself (having the same composition as the polyolefin resin), a part of the resin component constituting the polyolefin resin (for example, less than the total amount of specific resin components), and a polyolefin It includes some resin components (e.g., the total amount of a specific resin component among a plurality of resin components) constituting the system resin.
Moreover, "the remainder of polyolefin resin" means the polyolefin resin except the one part used at a process (a) among polyolefin resin. The remainder includes the remainder of the polyolefin resin itself (having the same composition as the polyolefin resin), the remainder of the resin component that constitutes the polyolefin resin, and the remaining resin component that constitutes the polyolefin resin.

<Additives>
Crosslinked resin moldings and crosslinkable resin compositions are various additives generally used in electric wires, electric cables, electric cords, members for automobiles, building members, sundries, sheets, foams, tubes and pipes. May be blended appropriately as long as the intended effect is not impaired. As such an additive, for example, a crosslinking assistant, an antioxidant, a lubricant, a metal deactivator, a flame retardant (auxiliary), another resin and the like can be mentioned.

  The coagent means a compound which forms a partially crosslinked structure with the resin component in the presence of the organic peroxide. For example, polyfunctional compounds and the like can be mentioned.

  Antioxidants such as, for example, 4,4′-dioctyl diphenylamine, N, N′-diphenyl-p-phenylenediamine, polymers of 2,2,4-trimethyl-1,2-dihydroquinoline, etc. Agent, pentaerythrityl-tetrakis (3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate), octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate A phenolic antioxidant such as 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, bis (2-methyl-4- (3) -N-alkylthiopropionyloxy) -5-tert-butylphenyl) sulfide, 2-mercaptobenzimidazole and Zinc salts, pentaerythritol - tetrakis - (3-laurylthiopropionate) sulfur antioxidants, and the like. The antioxidant can be added in an amount of preferably 0.1 to 15.0 parts by mass, more preferably 0.1 to 10 parts by mass, with respect to 100 parts by mass of the resin.

As metal deactivators, 1,2-bis (3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyl) hydrazine, 3- (N-salicyloyl) amino-1,2,4- And triazoles, 2,2'-oxamidobis- (ethyl 3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate) and the like.
As the lubricant, lubricants such as hydrocarbons, siloxanes, fatty acids, fatty acid amides, esters, alcohols, metal soaps and the like can be mentioned.

Next, the production method of the present invention will be specifically described.
In the production method of the present invention, the step (1) comprises, per 100 parts by mass of the polyolefin resin, 0.02 to 0.6 parts by mass of an organic peroxide, 0.1 to 140 parts by mass of silica, and a silane cup It is a process of mixing 2 to 15.0 parts by mass of a ring agent with a silanol condensation catalyst. Thereby, a crosslinkable resin composition is obtained as a mixture.

  Although the compounding quantity of polyolefin resin is not specifically limited in a process (1), It is preferable that it is the quantity used as 50 mass% or more in the content in the crosslinkable resin composition obtained by a process (1), and 70 It is preferable that it is the quantity used as mass% or more.

  In the step (1), the compounding amount of the organic peroxide is 0.02 to 0.6 parts by mass, preferably 0.04 to 0.4 parts by mass with respect to 100 parts by mass of the polyolefin resin. By setting the organic peroxide in this range, it is possible to prepare a silane grafter having excellent extrudability, without the cross-linking reaction between the resin components which are side reactions progressing and without generation of bumps. .

In the present invention, the compounding amount of silica is 0.1 to 140 parts by mass with respect to 100 parts by mass of the polyolefin resin. If the compounding amount of silica is less than 0.1 parts by mass, the silane coupling agent is easily volatilized, and the heat resistance of the obtained crosslinkable resin composition and the crosslinked resin molded product may be lowered. In addition, bumps may be generated, the molding material may be foamed, or the adhesiveness of the molding material may be increased, and in any case, problems in production may occur. On the other hand, if it exceeds 140 parts by mass, the heat resistance of the crosslinkable resin composition or the crosslinked resin molded product may be lowered, or the appearance, gel texture or the like may be generated. Furthermore, it may not be possible to produce a light-weight crosslinked resin molded article which is excellent in the above-mentioned properties.
The blending amount of silica can be reduced as long as the X value defined by the above formula (I) satisfies 5-1000. For example, the compounding amount of silica is 0.1 to 60 parts by mass in that a lightweight crosslinked resin molded product can be produced while satisfying the X value defined by the above formula (I) and maintaining the above characteristics. Is preferable, and 0.3 to 10 parts by mass is more preferable.

  The compounding quantity of a silane coupling agent is 2-15.0 mass parts with respect to 100 mass parts of polyolefin resin. A crosslinking reaction does not fully advance that the compounding quantity of a silane coupling agent is less than 2 mass parts, and desired flame resistance and mechanical characteristics can not be provided to a crosslinkable resin composition or a crosslinked resin molded object. There is. On the other hand, if it exceeds 15.0 parts by mass, melt-kneading may be difficult, and it may not be able to be formed into a desired shape during extrusion molding. The compounding amount of the silane coupling agent is preferably more than 4 parts by mass and 15 parts by mass or less, and more preferably more than 4 parts by mass and 12 parts by mass or less.

In the present invention, the BET specific surface area and the compounding amount of the silica and the compounding amount of the silane coupling agent are within the above-mentioned ranges so that the X value defined by the following formula (I) falls within the range of 5 to 1000. Is adjusted. That is, silica and a silane coupling agent are used in the combination in which the following X value becomes in the range of 5-1000.
Formula (I): X = ΣA / B
In the formula, ΣA represents the total amount of the product of the BET specific surface area Yi (m ² / g) of silica and the loading amount Zi of silica. Therefore, when using several silica, let the total amount of the product of BET specific surface area Yi and the compounding quantity Zi of each silica be ΣA. B represents the compounding quantity of a silane coupling agent.
The compounding amount Zi of silica and the compounding amount of the silane coupling agent are the ratio (parts by mass) with respect to 100 parts by mass of the polyolefin resin in the step (1).

  In the present invention, the X value defined by the above formula (I) defines the relationship (X value) between the silica used in step (a) and the silane coupling agent. This is based on the assumption that the relationship between the silane coupling agent and the silica is important even if an inorganic filler other than the silica is present. That is, since silica has good compatibility with the silane coupling agent, it is easy to form a strong bond between the silane coupling agent and the silica when the surface treatment is performed with the silane coupling agent. As a result, even if an inorganic filler other than silica is present, the silane coupling agent easily bonds to the silica. Therefore, it is considered that most of the silane coupling agent for silane grafting to the polyolefin resin is bonded to silica. Therefore, the above excellent properties or physical properties of the resulting crosslinked resin molded article are increased by the silane coupling agent bonded to the silica.

In the production method of the present invention, when the X value defined by the formula (I) falls within the range of 5 to 1000, it is possible to produce a light-weight crosslinked resin molded article having both heat resistance, appearance and mechanical properties.
Although the mechanism of the action is not clear yet, it is presumed as follows.
In the step (1), the polyolefin resin is heated and kneaded together with the silica and the silane coupling agent in the presence of the organic peroxide above the decomposition temperature of the organic peroxide. As a result, the organic peroxide is decomposed to generate a radical, and grafting of the polyolefin resin with the silane coupling agent occurs. In addition, the heating at this time also partially promotes the formation reaction of a chemical bond by the covalent bond between the silane coupling agent and a group such as a hydroxyl group on the surface of silica.

That is, in the production method of the present invention, silica and a silane coupling agent are used before and / or at the time of kneading with a polyolefin resin. As a result, the silane coupling agent is bonded to the silica by the alkoxy group, and is bonded to the uncrosslinked portion of the polyolefin resin by the ethylenically unsaturated group such as the vinyl group present at the other end to be held. Alternatively, the alkoxy group is physically and chemically adsorbed and retained in the holes or surface of the silica without being bonded to the silica. As described above, the silane coupling agent (which is considered to form a chemical bond with, for example, a hydroxyl group on the surface of the silica, etc.), which is strongly bound to the silica The reason is that, for example, interaction by hydrogen bond, interaction among ions, partial charge or dipole, action by chemical or physical adsorption, etc. can be formed.
In this state, when an organic peroxide is added and kneading is performed, at least two types of silane crosslinkable resins in which a silane coupling agent having a different bond to silica graft-reacts with a polyolefin resin are formed.

  Among the silane coupling agents, the silane coupling agent having a strong bond with the silica retains the bond with the silica by the above-mentioned kneading, and the ethylenically unsaturated group as the crosslinking group is a crosslink of the polyolefin resin It grafts with the site. In particular, when a plurality of silane coupling agents are present on the surface of one silica particle through a strong bond, a plurality of polyolefin resins bond via the silica particle. These reactions or bonds broaden the cross-linked network through the silica.

  The X value defined by formula (I) represents the surface area of silica relative to the amount of the silane coupling agent capable of binding to the surface. As the value of X, ie, the surface area Yi of the silica capable of binding a silane coupling agent, increases, the surface area of a certain amount of silica particles increases, and thus more silane coupling agents can be bound per unit surface area of the silica particles. Therefore, even if the loading of silica is reduced, the amount of silane coupling agent bound to silica can be maintained. As a result, the crosslinked network with silica is maintained, and the crosslinked resin molded product exhibits the above-described excellent properties.

However, when the X value becomes too small and becomes less than 5, the surface area of silica to the silane coupling agent becomes small, and the silane coupling agent becomes difficult to bond to silica (the amount of bonding is reduced). Therefore, the silane coupling agent may volatilize or cause a side reaction during melt-kneading. As a result, the resulting crosslinked resin molded product may have poor heat resistance and, in some cases, poor appearance. Moreover, it may become difficult to manufacture a crosslinked resin molded product.
On the other hand, when the X value becomes too large and exceeds 1050, the surface area of silica to the silane coupling agent becomes large, and the silane coupling agent is bonded to the silica by a strong bond. Therefore, almost no silane coupling agent can be formed which is weakly bonded to silica. For this reason, it becomes difficult to produce a silane grafting reaction, heat resistance can not be maintained, or polymer chains will be couple | bonded by a crosslinking agent. As a result, the resulting crosslinked resin molded product may be inferior in heat resistance, and in some cases, in appearance or mechanical properties.

  The X value defined by the formula (I) is preferably 5 to 650, more preferably 10 to 450, and still more preferably 10 to 350, from the viewpoint of achieving particularly excellent heat resistance. preferable.

  The X value defined by the formula (I) can be appropriately adjusted by the BET specific surface area or the compounding amount of silica or the compounding amount of the silane coupling agent.

  In the step (1), the blending amount of the silanol condensation catalyst is not particularly limited. For example, the amount is preferably 0.01 to 1 part by mass with respect to 100 parts by mass of the polyolefin resin, and 0.03 to 0. The amount is more preferably 6 parts by mass, and still more preferably 0.05 to 0.5 parts by mass. When the amount of the silanol condensation catalyst is in the above range, the crosslinking reaction sufficiently proceeds, and the heat resistance (particularly, high temperature heat resistance) and the deformability are excellent. In addition, the reaction between the silane coupling agents can be suppressed, and the foaming can be suppressed by gelation, bubbling and volatilization of the silane coupling agent.

In the case where an inorganic filler other than silica is used in the step (1), the amount of the inorganic filler to be added is appropriately set within a range that does not impair the intended effect. For example, the upper limit thereof is preferably 350 parts by mass, more preferably 300 parts by mass, and 250 parts by mass with respect to 100 parts by mass of the polyolefin resin in total with the compounding amount of the above-mentioned silica. It is further preferred that If the amount of the inorganic filler is too large, the silane coupling agent may be adsorbed to the inorganic filler, and the silane grafting reaction may not proceed smoothly, or mechanical properties may be affected.
In the step (1), the blending amounts of the other resins that can be used in addition to the above components and the above additives are appropriately set as long as the object of the present invention is not impaired.
In the step (1), it is preferred that the crosslinking coagent be not substantially mixed. Here, "not substantially contained or not mixed" means not actively adding or mixing the crosslinking aid, and does not exclude the unavoidable contained or mixed.

A process (1) has following process (a)-process (d). When the step (1) has these steps, the respective components can be melted and mixed uniformly, and the desired effect can be obtained.
Step (a): Process formula (I) X = ΣA / B in which an organic peroxide, a silica satisfying an X value defined by the following formula (I) of 5 to 1000 and a silane coupling agent are mixed
(Wherein, ΣA represents the total amount of the BET specific surface area of the silica (m ² / g) × the blended amount of the silica, and B represents the blended amount of the silane coupling agent)
Step (b): a step of melting and mixing the mixture obtained in step (a) and all or part of the polyolefin resin at a temperature above the decomposition temperature of the organic peroxide step (c): silanol condensation catalyst and carrier resin And (b) processing the remaining portion of the resin different from the polyolefin resin or the polyolefin resin step (d): the molten mixture obtained in the step (b) and the mixture obtained in the step (c), the polyolefin resin Melt mixing at a temperature above the melting temperature of

In the step (a), an organic peroxide, the above-mentioned silica, a silane coupling agent, and, if desired, another resin or an inorganic filler other than silica are mixed at the above-mentioned content. The mixing may be any treatment that can mix these components, and includes blending at a temperature below the decomposition temperature of the organic peroxide, for example, room temperature (25 ° C.).
In the step (a), a polyolefin resin may be present as long as the temperature is maintained.

  Next, the mixture and all or part of the polyolefin resin are melt-kneaded (also referred to as melt mixing) while being heated using a mixer such as a Banbury mixer (step (b)). This gives a silane masterbatch as a molten mixture.

The kneading temperature is a temperature equal to or higher than the decomposition temperature of the organic peroxide, preferably 150 to 230 ° C. At this kneading temperature, the above components melt, the organic peroxide decomposes and acts, and the necessary silane grafting reaction proceeds. The kneading conditions such as the kneading time can be set appropriately.
The kneading method may be any method commonly used for rubber, plastic and the like. As a kneading apparatus, a single screw extruder, a twin screw extruder, a roll, a Banbury mixer, various kneaders, etc. are used, for example.

  In the present invention, the step of preparing the mixture (step (a)) is a separate step from the step of melting and kneading (step (b)), the organic peroxide, the silica, the silane coupling agent and the polyolefin. The base resins and the like can be mixed together to prepare a melt mixture. For example, the step (a) can be performed in one step in combination with the step (b) of melting and mixing with a kneader or the like. Specifically, each component used for process (a) can be blended in the initial stage of a kneading process.

  In any of the step (a) and the step (b), it is preferable to mix the above-mentioned components without mixing the silanol condensation catalyst. Thereby, the condensation reaction of the silane coupling agent can be suppressed.

  The silane masterbatch prepared in step (b) contains at least two types of silane crosslinkable resins (silane graft polymers) in which a silane coupling agent graft-reacts with a polyolefin resin.

In the present invention, the silanol condensation catalyst and the carrier resin are mixed separately from the above steps (a) and (b) (step (c)). This gives a crosslink promoted masterbatch. This mixing may be any process that allows uniform mixing, and examples include mixing (melting mixing) performed under melting of the carrier resin.
As a carrier resin, when using a part of polyolefin resin at a process (b), the remainder of polyolefin resin can be used. In this case, preferably 99 to 40 parts by mass, more preferably 98.5 to 60 parts by mass are blended in the step (b), and 1 to 60 parts by mass in the step (c), more preferably Is blended in 1.5 to 40 parts by mass. In the present invention, a total of 100 parts by mass of the polyolefin-based resin used in both the step (b) and the step (c) is the basis of the blending amount of each component.

  On the other hand, when all of the polyolefin resins are used in the step (b), another resin different from this can be used in the step (c). Other resins are not particularly limited, and various resins can be mentioned. In this case, the blending amount of another resin is preferably 1 to 50 parts by mass, and more preferably 3 to 30 parts by mass with respect to 100 parts by mass of the polyolefin resin.

  The compounding amount of the silanol condensation catalyst is as described above, and is appropriately determined according to the compounding amount of the carrier resin.

Next, in the production method of the present invention, the melt mixture (silane masterbatch) obtained in step (b) and the mixture obtained in step (c) (crosslinking acceleration masterbatch) are melt mixed while heating ( Step (d)). Thereby, a crosslinkable resin composition is obtained as a molten mixture.
The mixing temperature may be a temperature that is equal to or higher than the melting temperature of the polyolefin resin or the carrier resin, and 150 to 230 ° C. is preferable.
Melt mixing can be performed, for example, in the same manner as melt mixing in step (b).
A process (1) can perform process (a)-(d) simultaneously or continuously.

  The resulting crosslinkable resin composition contains at least two types of silane crosslinkable resins. The crosslinkable resin composition is an uncrosslinked body in which the silane coupling agent is not silanol condensed. In practice, although partial crosslinking (partial crosslinking) is unavoidable under the melt mixing in step (d), the resulting crosslinkable resin composition retains at least the formability in the molding in step (2). Shall be

Next, the method for producing a crosslinked resin molded product of the present invention performs step (2) and step (3). That is, in the method for producing a crosslinked resin molded article of the present invention, the step (2) of obtaining a molded article by molding the obtained mixture is performed. In this step (2), it is sufficient that the mixture can be formed, and an appropriate forming method and forming conditions are selected according to the form of the formed article of the present invention. The molding method includes extrusion molding using an extruder, extrusion molding using an injection molding machine, and molding using another molding machine.
This step (2) can be carried out simultaneously with or sequentially to the step (d). That is, as an embodiment of the melt mixing in the step (d), there is an aspect in which the molding raw material is melt mixed in the melt molding, for example, in the extrusion molding or immediately before that. For example, in the case of producing an insulated wire or the like, molding materials of a silane masterbatch and a crosslinking promoting masterbatch are melt mixed, for example, in a coating apparatus, and then extrusion coated on the outer peripheral surface of a conductor, for example, A series of processes can be adopted.

  Like the crosslinkable resin composition, the molded article obtained in the step (2) is in a partially crosslinked state in which partial crosslinking is inevitable but the moldability in the step (2) is maintained.

In the method for producing a crosslinked resin molded article of the present invention, the step (3) of bringing the molded article obtained in the step (2) into contact with water is performed. Thereby, the silane coupling agent can be silanol-condensed to obtain a crosslinked resin molded product crosslinked.
The step (3) hydrolyzes the silane coupling agent grafted to the polyolefin-based resin with moisture by leaving the molded body in a wet heat treatment, warm water treatment, immersion in normal temperature water or standing at normal temperature, and cross linking Can be promoted. The contact conditions such as the contact time can be set as appropriate.

  Thus, the crosslinked resin molded article of the present invention is produced. As described later, this crosslinked resin molded product contains a resin component in which each of two types of silane crosslinkable resins is condensed via a siloxane bond.

In the present invention, it is possible to obtain a multicomponent base material and a very low specific gravity crosslinked resin molding. Therefore, for example, it is possible to obtain a low specific gravity rubber cross-linked body having reinforcing properties, a filler such as silica, and a low specific gravity rubber cross-linked body having wear resistance.
In that case, although depending on the base resin (polyolefin resin), by setting the compounding amount of silica to 10 parts by mass or less, the specific gravity is, for example, 1.0 g / cm ³ or less, further 0.95 g / cm. It is possible to obtain a molded body with a very low specific gravity of ³ or less.

The details of the reaction mechanism and the like in the production method of the present invention are not clear yet, but are considered as follows.
That is, by mixing the silane coupling agent with the silica before and / or at the time of kneading with the polyolefin resin, the volatilization of the silane coupling agent at the time of kneading can be suppressed. Therefore, the heat resistance and the appearance of the heat-resistant silane-crosslinked resin molded product can be prevented from being degraded. In addition, it is possible to form a silane coupling agent linked to a strong hydrogen bond with silica and a silane coupling agent linked to a weak bond.
Here, it is as above-mentioned that the relationship between a silica and a silane coupling agent is important.

When surface-treated silica is kneaded with a polyolefin resin at a temperature above its melting point in the presence of an organic peroxide, the surface-treated silica has a strong bond with silica A bond can be created between the polyolefin resin and the surface-treated silica via a silane coupling agent (reaction k).
On the other hand, the silane coupling agent having a weak bond with the silica is released from the silica and bonded with the polyolefin resin by a grafting reaction (reaction m). The silane coupling agent grafted onto the polyolefin resin by this (reaction m) is then mixed with a silanol condensation catalyst and brought into contact with moisture to cause a condensation reaction, resulting in crosslinking due to siloxane bond (reaction n).

Thus, the silane coupling agent bonded to the silica by a strong bond mainly contributes to high mechanical strength (tensile strength), and further to abrasion resistance, trauma resistance and reinforcement. In addition, the silane coupling agent bonded to the silica by a weak bond mainly contributes to the improvement of the degree of crosslinking.
Therefore, by controlling these bonds, it is possible to control the degree of crosslinking and mechanical strength as well as the abrasion resistance, the resistance to injury and the reinforcement.

  Therefore, the BET specific surface area of silica and the compounding amount thereof, and the compounding amount of the unsaturated group-containing silane coupling agent are adjusted to a specific range in which the X value defined by the above formula (I) satisfies 5-1000. In addition to the high heat resistance, the reaction k, the reaction m, and the reaction n, in combination with each other, have excellent mechanical properties and appearance, and further abrasion resistance, in the crosslinked resin molded article and the crosslinkable resin composition. Trauma resistance can be provided.

  In addition, since silica has a large surface area per unit mass, it is possible to achieve a combination of high mechanical strength, wear resistance, reinforcement, trauma resistance and heat resistance with a small blending amount. Therefore, it becomes possible to obtain a crosslinked resin molded product having low specific gravity heat resistance, high mechanical strength, further abrasion resistance, reinforcement, and trauma resistance, and a crosslinkable resin composition capable of forming the same.

  Furthermore, a material imparting flame retardancy, for example, a metal hydrate such as magnesium hydroxide and aluminum hydroxide, a flame retardant auxiliary such as antimony trioxide, and a flame retardant such as a bromine flame retardant or a chlorine flame retardant By doing this, excellent flame retardancy can be imparted. Moreover, heat resistance, high mechanical strength, wear resistance, reinforcement, and trauma resistance are given by adding various fillers such as thermal conductivity by adding boron nitride and alumina. In addition, various physical properties can be satisfied.

The production method of the present invention is applied to the production of products (including semi-finished products and parts) requiring heat resistance, products requiring strength, products requiring flame retardancy, and products such as rubber materials. Can. Therefore, the molded article of the present invention is regarded as such a product. At this time, the molded article may be a molded article containing a crosslinked resin molded article, or may be a molded article formed only of the crosslinked resin molded article.
As a molded article of the present invention, for example, covering material of electric wire such as heat resistant flame retardant insulated wire or heat resistant flame retardant cable, material of rubber alternative electric wire / cable, other heat resistant flame retardant electric wire parts, flame retardant heat resistant sheet, flame retardant heat resistant film Automotive automotive parts, automotive cushioning materials, power plugs, connectors, packings, cushioning materials, vibration-proof materials, boxes, tape substrates, tubes, sheets, wiring materials used for internal and external wiring of electric and electronic devices , Insulators of electric wires, sheaths and the like.

When the molded article of the present invention is an extrusion molded article such as a wire, a cable, a tube, a cushion material, a conductor is coated and molded while being melt-kneaded in an extrusion coating apparatus, or extruded into a tube shape It can be extruded into a rod-like or sheet-like form (step (d) and step (2)).
Moreover, when inject-molding to a box, various components, etc., it can obtain by introduce | transducing a molding material into an injection molding machine and inject-molding.
It is possible to maintain high heat resistance by bringing these molded articles into contact with moisture such as standing at normal temperature, standing with moist heat, warm water treatment or the like to cause crosslinking.
The thickness of these molded articles is not generally determined depending on the application etc., but is usually about 0.1 to 50 mm.

EXAMPLES The present invention will be described in more detail based on examples given below, but the invention is not meant to be limited by these.
In Tables 1 to 4, the numerical values relating to the composition in each example represent parts by mass unless otherwise specified.

Examples 1 to 25 (Examples 2, 8, 9, 13, 15, and 18 to 20 have a missing number), Comparative Examples 1 to 5 and Reference Examples 1 to 8 use the following components, and The source was set to the conditions shown in Tables 1 to 4, and the evaluation described later was shown together.

The detail of each compound shown in Table 1-Table 4 is shown below.
<Polyolefin resin>
(Polyethylene: PE)
"Evolue SP 0540 F" (trade name, manufactured by Prime Polymer Co., Ltd., linear metallocene polyethylene (LLDPE))
"UE320" (Novatec PE (trade name), manufactured by Japan Polyethylene Corporation, linear low density polyethylene (LLDPE))
(Ethylene-vinyl acetate copolymer: EVA)
"V 5274" (Evaflex V 5274 (trade name), ethylene-vinyl acetate copolymer resin, VA content 17% by mass, Mitsui-Dupont Chemical Co., Ltd.)
(Polypropylene: PP)
"PB222A" (trade name, manufactured by Sun Aroma, random polypropylene)
(Ethylene-propylene-diene rubber: EPDM)
"Nodel IP-4760P" (trade name, manufactured by Dow Chemical Co.)
"Nodell IP-4520P" (trade name, manufactured by Dow Chemical Co.)
(Styrenic elastomer: SEPS)
"Septon 4077" (trade name, manufactured by Kuraray, SEPS, styrene content: 30% by mass)
(Oil: OIL)
"Diana Process Oil PW-90" (brand name, Idemitsu Kosan, paraffin oil)

<Silica>
"Aerosil 200" (trade name, manufactured by Nippon Aerosil, hydrophilic fumed silica, non-crystalline silica, BET specific surface area Yi: 200 m ² / g)
"Crystalite 5X" (trade name, manufactured by Ryumori, crystalline silica, BET specific surface area Yi: 12 m ² / g)
"Aerosil 90" (trade name, manufactured by Nippon Aerosil, hydrophilic fumed silica, non-crystalline silica, BET specific surface area Yi: 90 m ² / g)
"Aerosil OX50" (trade name, manufactured by Nippon Aerosil, hydrophilic fumed silica, non-crystalline silica, BET specific surface area Yi: 50 m ² / g)
“SFP-20M” (trade name, manufactured by Denki Kagaku Kogyo Co., Ltd., crystalline silica, BET specific surface area Yi: 11.3 m ² / g)
"SFP-30M" (trade name, manufactured by Denki Kagaku Kogyo Co., Ltd., crystalline silica, BET specific surface area Yi: 6.2 m ² / g)

<Inorganic fillers other than silica>
(Calcium carbonate)
"SOUNDON 2200" (trade name, manufactured by Bihoku Powder Co., Ltd., BET specific surface area 2.2 m ² / g)
(Magnesium hydroxide)
"Kisuma 5L" (trade name, manufactured by Kyowa Chemical Co., Ltd., BET specific surface area 5.8 m ² / g)
(Aluminum hydroxide)
"HIZU-LIGHT H42M" (trade name, manufactured by Showa Denko KK, BET specific surface area 5 m ² / g)
(talc)
"K-1 Talc" (trade name, manufactured by Nippon Talc Industrial Co., Ltd., BET specific surface area Yi: 7 m ² / g)

<Silane coupling agent>
"KBM 1003" (trade name, manufactured by Shin-Etsu Chemical Co., Ltd., vinyltrimethoxysilane)
<Organic peroxide>
"Perhexa 25B" (trade name, manufactured by NOF Corporation, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexane, decomposition temperature 149 ° C)
<Silanol condensation catalyst>
Adekastab OT-1 (trade name, manufactured by ADEKA, dioctyl tin dilaurate)

<Antioxidant>
“Irganox 1010” (trade name, manufactured by BASF, pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate])

(Examples 1 to 25, Comparative Examples 1 to 5 and Reference Examples 1 to 8 )
In each example, a part (25 parts by mass with respect to the total amount of the polyolefin-based resin) of the polyolefin-based resin was used as a carrier resin of the crosslinking-promoting masterbatch (sometimes referred to as crosslinking-promoted MB). This carrier resin was polyethylene "UE320" which is one of resin components constituting the polyolefin resin.

First, Example 3, 5, 7, 11, 12, 23 and Example except Example 1, For the comparative examples and reference examples, Table 1 to Table 4 "Composition P (composition of silane masterbatch)" column Dry the silica, inorganic filler other than silica (calcium carbonate, magnesium hydroxide, aluminum hydroxide, aluminum oxide or talc), silane coupling agent and organic peroxide for 3 minutes at room temperature (25 ° C) Blended.
Next, the mixture obtained and the remaining components shown in the "composition P" column of Tables 1 to 4 are mixed in the mixing ratio shown in the "composition P" columns of Tables 1 to 4 by 2L Banbury mixer made by Nippon Roll To the After kneading for about 12 minutes at a rotation number of 35 rpm with this mixer, the material was discharged at a temperature of 180 to 190 ° C. to obtain a silane master batch (sometimes referred to as silane MB).

For Examples 3 , 5 , 7 and Reference Example 1, all the components shown in the "Composition P" column of Table 1 were introduced into Nippon Roll 2L Banbury Mixer at the mixing ratio shown in the "Composition P" column of Table 1. . After idling for about 2 minutes with this mixer, the mixture was kneaded for about 12 minutes and then discharged at a material discharge temperature of 180 to 190 ° C. to obtain silane MB.

For Examples 11, 12 and 23 , the silane coupling agent and the organic peroxide are first mixed at room temperature (25 ° C.) in the compounding ratio shown in the “composition P” column of Table 2 and Table 3, and then polyolefin A system resin, silica, an inorganic filler other than silica, and an antioxidant were charged into a 2L Banbury mixer made by Nippon Roll Co., and thereafter, a mixture of a silane coupling agent and an organic peroxide was charged. Thereafter, they were mixed in a Banbury mixer at room temperature (25 ° C.), and subsequently melt mixed at a material discharge temperature of 180 ° C. to 190 ° C. at a rotational speed of 35 rpm for about 15 minutes to obtain silane MB.

Each of the silanes MB obtained in Examples 1 to 25 and Reference Examples 1 to 8 contains at least two types of silane crosslinkable resins in which a silane coupling agent is graft-reacted to a polyolefin resin.
In addition to the compounding quantity of each component, X value etc. prescribed | regulated by said Formula (I) were shown in the "composition P" column of Table 1-4.

  Then, the components shown in the “composition Q (composition of crosslinking acceleration MB)” column in Tables 1 to 4 are mixed by the Banbury mixer at the mixing ratio shown in the “composition Q” columns in Tables 1 to 4 It melt-mixed by discharge temperature 180-190 degreeC, and obtained crosslinking acceleration | stimulation MB.

Then, dry blend the silane MB and the crosslinking accelerating MB at the mixing ratio shown in the “mixing ratio” column of Tables 1 to 4, and use a 40 mm extruder with L / D = 24 (compression section screw temperature 190 ° C., head temperature 200 ° C. ) And molded by T-die extrusion into two types of sheet-like compacts 1 mm thick and 2 mm thick while being melt mixed in the extruder screw.
Further, in the same manner using an extruder, silane MB and crosslink-promoted MB were coated on the outside of the 1 / 0.8 TA conductor with a thickness of 1 mm to obtain a wire having an outer diameter of 2.8 mm.

The obtained two sheet-like compacts and wires were left in an atmosphere at a temperature of 60 ° C. and a humidity of 95% for 24 hours. Thus, the insulated wire which has a sheet | seat which consists of each of 2 types of crosslinked resin molded objects, and a crosslinked resin molded object as coating | coated was manufactured.
The cross-linked resin molded product was foaming in both of the two types of sheets and the insulated wire manufactured in Comparative Example 1.

  The following evaluation was performed about the manufactured sheet | seat and an insulated wire, and the result was shown in Table 1-Table 4.

<Specific gravity>
The specific gravity of the 2 mm-thick sheet produced in Examples 1 and 3 and Reference Examples 1 to 3 was measured.
Specific gravity was measured based on JIS K 7221 (Method A).

<Mechanical characteristics>
Tensile tests were carried out on the 1 mm thick sheets produced in each example. This tensile test was conducted based on JIS K 6723 using a JIS No. 3 dumbbell test piece punched out of a crosslinked resin molded sheet. The measurement was carried out at a measurement temperature of 25 ° C., a marked line of 20 mm, and a tensile speed of 200 mm / min, and the tensile strength (MPa) and the elongation (%) were measured.
When the tensile strength is 10 MPa or more, the product level passes, and when the elongation is 200% or more, the product level passes.

<Heating deformation test (sheet)>
The following heat distortion test was done as heat resistance of the sheet which consists of a crosslinked resin molding. In this heat deformation test, the heat deformation rate was measured under the conditions of a measurement temperature of 120 ° C. and a load of 5 N based on the “heat deformation test” prescribed in JIS K 6723 for a sheet of 2 mm in thickness.
In the evaluation, a case where the heat deformation rate is 40% or less is regarded as a product level, and a case where it exceeds 40% is regarded as a product level (represented by “C” in Tables 1 to 4).
In Tables 1 to 4, in addition to the heat deformation rate, the results of the heat deformation test of the sheet also include the following evaluation symbols. The evaluation symbol is “C” when rejected, “B” when the heating deformation rate is more than 35% and 40% or less, “A”, 30 when it is more than 30% and 35% or less. The case of% or less is represented by "AA".

<Heating deformation test (insulated wire)>
The following heat distortion test was done as heat resistance of the insulated wire which has a covering which consists of a crosslinked resin molding. In this heating deformation test, the rate of decrease in thickness of the insulated wire was measured based on JIS C 3005 under the conditions of a measurement temperature of 120 ° C. and a load of 5 N.
In the evaluation, when the reduction rate is 50% or less, it is regarded as a product level, and when it exceeds 50%, it is regarded as a product level.
In Tables 1 to 4, in addition to the reduction rate, the results of the heating deformation test of the insulated wire are shown together with the following evaluation symbols. The evaluation symbol is “C” for rejection, “B” for reduction rate of more than 40% and 50% or less, “A”, 35% and 40% or less. The following cases are represented by "AA".

<Extrusion appearance characteristics of insulated wire>
The extrusion appearance characteristics of the insulated wire were evaluated by observing the extruded appearance when manufacturing the insulated wire. Specifically, when the molten mixture of silane MB and crosslink-promoting MB was extruded with a screw diameter of 30 mm at a linear velocity of 15 m / min, the appearance of the electric wire was "A" when the appearance was good Those that were somewhat bad were designated as "B", and those that were significantly inferior in appearance were designated as "C". "A" and "B" pass as product level.

The following can be understood from the results of Tables 1 to 4.
According to Examples 1 to 25, a sheet made of a crosslinked resin molded article having excellent heat resistance, appearance and mechanical properties, and an insulated wire having a coating formed of the crosslinked resin molded article can be manufactured. In particular, even if the blending amount of silica is as small as 0.3 to 60 parts by mass with respect to 100 parts by mass of the polyolefin-based resin, it is possible to manufacture a sheet and an insulated wire sufficiently exhibiting desired heat resistance.
In addition, when silica and a silane coupling agent are used in combination so that the X value defined by the above formula (I) falls within the above-mentioned preferable range, heat resistance can be achieved without impairing the appearance and mechanical properties of the crosslinked resin molded product. I was able to improve further.
Furthermore, the sheets produced in Examples 1 and 3 were small in specific gravity and lightweight. In the insulated wire manufactured in Examples 1 and 3 , and in the sheet and the insulated wire manufactured in Examples other than Examples 1 and 3 , the weight can be similarly reduced.

  In particular, in Examples 21 to 24, the X value defined by the above-mentioned formula (I) is fixed, and the blending amount of magnesium hydroxide which is an inorganic filler other than silica is gradually increased. In these examples, mechanical properties tended to decrease as the content of magnesium hydroxide increased. However, the mechanical properties maintained the pass level, and the thermal deformation rates were approximately the same value. Thus, when silica is used as the filler, when the X value defined by the above formula (I) is set within the above range for silica, the resulting crosslinked resin molded article has excellent heat resistance, appearance and mechanical properties. It turned out that it had it.

  Further, according to Examples 1 to 25, a crosslinkable resin composition and a silane master batch capable of producing a crosslinked resin molded article having both excellent heat resistance, appearance and mechanical properties, and more preferably lightweight were able to be prepared.

On the other hand, in Comparative Example 1, the X value defined by the above-mentioned formula (I) was small, and the tensile strength, the heat deformation test and the extrusion appearance property were not acceptable. On the other hand, in each of Comparative Examples 2, 3 and 5, the X value defined by the above-mentioned formula (I) was large, and at least the heat deformation test failed.
In Comparative Example 4, the blending amount of the silane coupling agent was small, and the heat deformation test was not successful.

Claims (9)

It is a manufacturing method of the crosslinked resin molding which has following process (1), process (2), and process (3) ,
Process (1): Polyole containing 25% by mass or more of ethylene-propylene-diene rubber
Organic peroxide 0.02 to 0.6 quality per 100 parts by mass of fin-based resin
Parts, 0.1 to 140 parts by mass of silica, and an ethylenically unsaturated group
2 to 15.0 parts by mass of a silane coupling agent containing
The silane coupling agent and the polyolefin are mixed with a cocatalyst.
By including a resin with a resin, a bridge containing a silane crosslinkable resin is obtained.
Step to obtain a bridge resin composition (2): to obtain a molded body by molding the said crosslinkable resin composition obtained in step (1)
Step (3): The molded product obtained in the step (2) is brought into contact with water to obtain a crosslinked resin molded product
Process

The manufacturing method of the crosslinked resin molding whose said process (1) has following process (a)-process (d) .
Process (a): The organic peroxide and the X value defined by the following formula (I) are 33.3 to 10
Mixing the silica satisfying 00 and the silane coupling agent
Formula (I) X = ΣA / B
(Wherein ΣA is the BET specific surface area (m ² / g) of silica and the blending amount of silica
And B represents the compounding amount of the silane coupling agent. )
Step (b): The mixture obtained in the step (a) and all of the polyolefin resin
Partially melt-mix at a temperature above the decomposition temperature of the organic peroxide ,
Grafting reaction between the silane coupling agent and the polyolefin resin
To obtain a silane masterbatch containing a silane crosslinkable resin
Process step (c): the above-mentioned polyolefin-based resin as the silanol condensation catalyst and carrier resin
Process of mixing the resin different from fat or the remaining part of the polyolefin-based resin Process (d): Silane master batch obtained in the process (b), and the process (c)
Step of mixing with the obtained mixture to obtain a crosslinkable resin composition   The method for producing a crosslinked resin molded article according to claim 1, wherein the silane coupling agent is mixed in an amount of more than 4 parts by mass and 15.0 parts by mass or less with respect to 100 parts by mass of the polyolefin resin.   The method for producing a crosslinked resin molded product according to claim 1, wherein the silica is crystalline silica.   The method for producing a crosslinked resin molding according to any one of claims 1 to 3, wherein the silane coupling agent is vinyltrimethoxysilane or vinyltriethoxysilane. Ethylene - propylene - diene rubber per 100 parts by mass of the polyolefin resin containing 25% by mass or more, and an organic peroxide 0.02 to 0.6 parts by weight of silica 0.1 to 140 parts by weight, ethylenically unsaturated A silane crosslinking agent is obtained by mixing 2 to 15.0 parts by mass of a silane coupling agent containing a group having a saturated group with a silanol condensation catalyst and causing the silane coupling agent and the polyolefin resin to undergo a grafting reaction. having obtained Ru step a crosslinkable resin composition comprising rESIN, a method for producing a crosslinkable resin composition,
The manufacturing method of the crosslinkable resin composition whose process to mix has a following process (a)-process (d) .
Process (a): The organic peroxide and the X value defined by the following formula (I) are 33.3 to 10
Mixing the silica satisfying 00 and the silane coupling agent
Formula (I) X = ΣA / B
(Wherein ΣA is the BET specific surface area (m ² / g) of silica and the blending amount of silica
And B represents the compounding amount of the silane coupling agent. )
Step (b): The mixture obtained in the step (a) and all of the polyolefin resin
Partially melt-mix at a temperature above the decomposition temperature of the organic peroxide ,
Grafting reaction between the silane coupling agent and the polyolefin resin
To obtain a silane masterbatch containing a silane crosslinkable resin
Process step (c): the above-mentioned polyolefin-based resin as the silanol condensation catalyst and carrier resin
Process of mixing the resin different from fat or the remaining part of the polyolefin-based resin Process (d): Silane master batch obtained in the process (b), and the process (c)
Step of mixing with the obtained mixture to obtain a crosslinkable resin composition   A crosslinkable resin composition produced by the method for producing a crosslinkable resin composition according to claim 5.   The crosslinked resin molded object manufactured with the manufacturing method of the crosslinked resin molded object of any one of Claims 1-4.   A molded article comprising the crosslinked resin molded article according to claim 7. Ethylene - propylene - diene rubber per 100 parts by mass of the polyolefin resin containing 25% by mass or more, and an organic peroxide 0.02 to 0.6 parts by weight of silica 0.1 to 140 parts by weight, ethylenically unsaturated Crosslinking obtained by mixing 2 to 15.0 parts by mass of a silane coupling agent containing a group having a saturated group with a silanol condensation catalyst and causing the silane coupling agent and the polyolefin resin to undergo a grafting reaction A silane masterbatch used in the production of a functional resin composition,
The silane masterbatch obtained by the following process (a) and process (b) .
Process (a): The organic peroxide and the X value defined by the following formula (I) are 33.3 to 10
Mixing the silica satisfying 00 and the silane coupling agent
Formula (I) X = ΣA / B
(Wherein ΣA is the BET specific surface area (m ² / g) of silica and the blending amount of silica
And B represents the compounding amount of the silane coupling agent. )
Step (b): The mixture obtained in the step (a) and all of the polyolefin resin
Partially melt-mix at a temperature above the decomposition temperature of the organic peroxide ,
Grafting reaction between the silane coupling agent and the polyolefin resin
Step of