JP6639937B2 - Method for producing heat-resistant silane-crosslinked thermoplastic elastomer molded article, silane masterbatch, and heat-resistant product - Google Patents

Description

  The present invention relates to a method for producing a heat-resistant silane-crosslinked thermoplastic elastomer molded article, a silane masterbatch for obtaining the molded article, and a heat-resistant product. In particular, the present invention relates to a heat-resistant silane cross-linked molded article of a thermoplastic elastomer excluding styrene-based and olefin-based thermoplastic elastomers.

  Thermoplastic elastomers are materials that have the flexibility and elasticity of rubber but flow at a certain temperature or higher and can be processed in the same manner as thermoplastic resins. It is used in various fields such as parts for use.

In general, a molded article of a rubber composition (eg, EPDM, CR, NBR, ACM, etc.) is used for applications requiring high flexibility or elasticity. In order to use the rubber composition as a molded article, generally, It is necessary to crosslink the rubber. This is because the rubber that has not been crosslinked is a fluid and flows when a force is applied for a long period of time, and the molded body is deformed.
As a method for crosslinking the rubber in the rubber composition, a chemical crosslinking method such as peroxide crosslinking or sulfur crosslinking is generally used. However, in the chemical cross-linking method, it is necessary to hold the molded article of the rubber composition at a high temperature and a high pressure for a relatively long time. Therefore, a large-scale facility is required for the rubber cross-linking step, and the production speed is slow, which causes an increase in production cost.

  In contrast, thermoplastic elastomers have the moldability of thermoplastic resins that can be molded and molded at high temperatures, but have the property of being flexible and exhibiting rubber elasticity without undergoing a crosslinking step after cooling. Have. For this reason, thermoplastic elastomers generally have higher manufacturability than rubber products, and the manufacturing cost can be reduced. Therefore, it is widely used as a substitute for rubber products.

  By the way, in the crosslinked rubber (crosslinked rubber), a new covalent bond is introduced between the molecular chains of the rubber, whereby the fluidity of the rubber is impaired, and the rubber exhibits elasticity. On the other hand, a thermoplastic elastomer is generally composed of a soft segment that is flexible at a use temperature and a hard segment that is rigid at a use temperature, and this hard segment is a crosslinked structure referred to as a crosslinked rubber (for example, the above-described covalent bond). Formation). At a temperature higher than the temperature at which the hard segment flows, the thermoplastic elastomer has fluidity, and therefore has a moldability similar to that of the thermoplastic resin at a high temperature as described above.

  However, since the thermoplastic elastomer exhibits rubber elasticity according to the above-described principle, the thermoplastic elastomer becomes plastic as it approaches the flow temperature of the hard segment, and cannot be used near the flow temperature. For this reason, the thermoplastic elastomer may be inferior to the crosslinked rubber from the viewpoint of heat resistance.

Therefore, to improve the heat resistance of the thermoplastic elastomer, cross-linking of the thermoplastic elastomer has been studied.
As a method for crosslinking a thermoplastic elastomer, generally, in addition to the above-described chemical crosslinking, an electron beam crosslinking method and a silane crosslinking method (also referred to as a water crosslinking method) can be mentioned. Above all, the silane cross-linking method does not require special equipment compared to the chemical cross-linking method and the electron beam cross-linking method. No cross-linking step is required. Therefore, the silane cross-linking method is advantageous from the viewpoint of manufacturability, and is suitable as a method of cross-linking a thermoplastic elastomer in that it utilizes the high manufacturability of a thermoplastic elastomer.

  As a method for crosslinking a thermoplastic elastomer, for example, a method described in Patent Document 1 can be mentioned. Specifically, a silane compound having an unsaturated group in a polyolefin-based thermoplastic elastomer, a composition containing a free radical generator and a silanol condensation catalyst is melt-kneaded to obtain a silane-grafted polyolefin-based resin composition, and then This is a method in which this is molded and the molded product is brought into contact with moisture to cause silane crosslinking.

JP-A-10-237136

  However, in the method described in Patent Document 1, when a thermoplastic elastomer other than a styrene-based or polyolefin-based thermoplastic elastomer is used instead of the polyolefin-based thermoplastic elastomer, heat resistance to an uncrosslinked thermoplastic elastomer is improved. A thermoplastic elastomer molded article (excellent in heat resistance) and also excellent in appearance could not be obtained.

The present invention solves the above-mentioned problems, and uses a thermoplastic elastomer other than styrene-based and olefin-based, a method for producing a heat-resistant silane-crosslinked thermoplastic elastomer molded article having excellent heat resistance and appearance, and a method for producing the same. An object of the present invention is to provide a heat-resistant silane crosslinked thermoplastic elastomer molded article to be obtained.
Another object of the present invention is to provide a silane masterbatch capable of forming the heat-resistant silane-crosslinked thermoplastic elastomer molded article.
A further object of the present invention is to provide a heat-resistant product comprising the heat-resistant silane-crosslinked thermoplastic elastomer molded article having the above-mentioned excellent properties.

  The present inventors have found that even with a base elastomer containing a thermoplastic elastomer other than styrene-based and olefin-based elastomers, a graft reaction of a silane coupling agent to the thermoplastic elastomer can be sufficiently caused by a specific silane crosslinking method described below. Further, they have found that the crosslinked thermoplastic elastomer molded article obtained by this production method has both excellent heat resistance and appearance. That is, a mixture containing a base elastomer containing a thermoplastic elastomer other than a styrene-based or olefin-based elastomer and an organic peroxide, an inorganic filler, and a silane coupling agent in a specific ratio is melted at a temperature equal to or higher than the decomposition temperature of the organic peroxide. By kneading, mixing the obtained composition and the silanol condensation catalyst, and by a specific production method including a molding step, it has been found that a heat-resistant silane-crosslinked thermoplastic elastomer molded article having excellent heat resistance and appearance can be produced. . The present inventors have further studied based on this finding, and have accomplished the present invention.

That is, the object of the present invention has been achieved by the following means.
(1) to the scan styrene-based and the base elastomer 100 parts by weight containing a thermoplastic elastomer other than the olefin, and an organic peroxide 0.01 to 0.5 parts by weight, the inorganic filler 0.5 to 300 parts by weight And a heat-resistant silane-crosslinked thermoplastic elastomer molded article having 1 to 15 parts by mass of a silane coupling agent having a graft reaction site capable of performing a graft reaction with the base elastomer and capable of binding or adsorbing to the inorganic filler. In manufacturing
Step (a-1): a step of preparing a mixture by mixing at least the inorganic filler and the silane coupling agent in the above-mentioned quantitative ratio,
Step (a-2): melt-kneading the mixture obtained in the step (a-1) and the base elastomer at a temperature not lower than the decomposition temperature of the organic peroxide in the presence of the organic peroxide. A step of preparing a silane master batch containing a silane crosslinkable thermoplastic elastomer by performing a graft reaction between the base elastomer and the silane coupling agent.
A step of having (a),
Shaping after mixing the pre Symbol step (a) silane masterbatch silanol condensation catalyst obtained by the (b),
Method for producing a heat resistant silane crosslinked thermoplastic elastomer molded body and a step (c) to crosslink with the previous SL molded body obtained in step (b) is contacted with water.
(2) Production of the heat-resistant silane-crosslinked thermoplastic elastomer molded article according to (1), wherein the thermoplastic elastomer has at least one of an amide bond, a urethane bond, an ester bond, and an imide bond in a main chain. Method.
(3) The step (b) comprises:
(B-1) a step of mixing a silanol condensation catalyst and a carrier to prepare a catalyst master batch;
(B-2) a step of molding after mixing the masterbatch and the catalyst masterbatch,
The method for producing a heat-resistant silane-crosslinked thermoplastic elastomer molded article according to (1) or (2), comprising:
(4) The inorganic filler according to any one of (1) to (3), wherein the inorganic filler contains at least one selected from the group consisting of silica, magnesium hydroxide, aluminum hydroxide, calcium carbonate, and antimony trioxide. A method for producing the heat-resistant silane-crosslinked thermoplastic elastomer molded article according to the above.
(5) The method for producing a heat-resistant silane-crosslinked thermoplastic elastomer molded article according to any one of (1) to (4), wherein the inorganic filler contains silica.
(6) The heat-resistant silane-crosslinked thermoplastic elastomer molding according to any one of (1) to (5), wherein the content of the inorganic filler is 1 to 150 parts by mass with respect to 100 parts by mass of the base elastomer. How to make the body.
(7) The heat-resistant silane crosslinking heat according to any one of (1) to (6), wherein the silane coupling agent includes at least one selected from the group consisting of vinyltrimethoxysilane and vinyltriethoxysilane. A method for producing a plastic elastomer molded article.
(8) The method for producing a heat-resistant silane-crosslinked thermoplastic elastomer molded article according to any one of (1) to (7), wherein the melt-kneading in the step (a) is performed by a closed mixer.
(9) A heat-resistant silane-crosslinked thermoplastic elastomer molded article produced by the production method according to any one of (1) to (8).
(10) A heat-resistant product comprising the heat-resistant silane crosslinked thermoplastic elastomer molded article according to (9).
(11) The heat-resistant product according to (10), wherein the heat-resistant silane-crosslinked thermoplastic elastomer molded article is a coating of an electric wire or an optical fiber cable.
(12) With respect to 100 parts by mass of a base elastomer containing a thermoplastic elastomer other than styrene-based and olefin-based, 0.01 to 0.5 parts by mass of an organic peroxide and 0.5 to 300 parts by mass of an inorganic filler. A master batch mixture obtained by mixing 1 to 15 parts by mass of a silane coupling agent and a silanol condensation catalyst having a graft reaction site capable of performing a graft reaction with the base elastomer and capable of bonding or adsorbing to the inorganic filler . A silane master batch used for production,
A mixture obtained by mixing at least the inorganic filler and the silane coupling agent in the above-described ratios and the base elastomer are melt-kneaded at a temperature equal to or higher than the decomposition temperature of the organic peroxide in the presence of the organic peroxide. And a silane crosslinkable thermoplastic elastomer obtained by a graft reaction between the base elastomer and the silane coupling agent.

  In this specification, a numerical range represented by using “to” means a range including numerical values described before and after “to” as a lower limit and an upper limit.

According to the present invention, by cross-linking the thermoplastic elastomer by the silane cross-linking method described above, heat resistance can be further improved, and cross-linking having an excellent appearance when processed into, for example, an electric wire or a cable. A molded article (heat-resistant silane crosslinked thermoplastic elastomer molded article) can be obtained with high production efficiency.
Therefore, according to the present invention, a method for producing a heat-resistant silane-crosslinked thermoplastic elastomer molded article having excellent heat resistance and appearance using a thermoplastic elastomer other than styrene-based and olefin-based thermoplastic elastomer molded articles and a heat-resistant silane-crosslinked thermoplastic elastomer molded article. Can be provided. Further, it is possible to provide a silane masterbatch capable of forming the heat-resistant silane-crosslinked thermoplastic elastomer molded article, and a heat-resistant product containing the heat-resistant silane-crosslinked thermoplastic elastomer molded article.

First, each component used in the present invention will be described.
<Base elastomer>
The base elastomer used in the present invention contains at least one type of thermoplastic elastomer other than styrene and olefin.

  Thermoplastic elastomer is a polymer material that can be molded by plasticizing at a certain temperature or higher and exhibiting fluidity, and having both elasticity and flexibility like rubber at a temperature lower than the predetermined temperature. It is. The thermoplastic elastomer has a soft segment having flexibility at a use temperature and a hard segment which does not flow but maintains a shape like a crosslinking point. The hard segment has no fluidity in the operating temperature range. The thermoplastic elastomer may be a block polymer in which a soft segment and a hard segment are present in one polymer chain, and are a blend of a rigid polymer (hard segment) and a soft polymer (soft segment). There may be.

The thermoplastic elastomer used in the present invention is preferably a thermoplastic elastomer having at least one of an ester bond, an amide bond, a urethane bond, and an imide bond in the main chain of the thermoplastic elastomer. More preferably, it is in the inner hard segment.
The thermoplastic elastomer having at least one of an ester bond, an amide bond, a urethane bond, and an imide bond in the main chain is not particularly limited, and examples thereof include a polyester elastomer, a polyamide elastomer, a polyurethane elastomer, and a polyimide elastomer, respectively. And the like.
Further, the thermoplastic elastomer may have two or more kinds of the above-mentioned bonds in the main chain, and may have an ether bond and / or a carbonate bond in addition to the above-mentioned bonds. Examples of such a thermoplastic elastomer include, for example, a polyester elastomer having a polyether in a soft segment in a main chain, a polyurethane elastomer having a polyester in a soft segment in a main chain, and a polyamide elastomer having a polyester in a soft segment in a main chain. , Polyimide urethane elastomer, polyimide ester elastomer and the like.

  Examples of the thermoplastic elastomer having an ester bond in at least a part of the main chain include a polyester elastomer. Specifically, an elastomer having an ester bond in the hard segment in the main chain, or a polyamide elastomer having an ester bond in the soft segment in the main chain, a polyurethane elastomer having a urethane bond in the soft segment in the main chain, or An elastomer having an ester bond in a soft segment in the main chain, such as a polyimide ester elastomer, may be used. The polyester elastomer is preferably an elastomer having an ester bond in a hard segment in the main chain, more preferably having an ester bond in a hard segment in the main chain, and more preferably having an ether bond or an ester bond in a soft segment in the main chain. .

  Examples of the thermoplastic elastomer having an amide bond in at least a part of the main chain include a polyamide elastomer. The polyamide elastomer is preferably an elastomer having an amide bond in the hard segment in the main chain, having an amide bond in the hard segment in the main chain, and having an ether bond or an ester bond or both in the soft segment in the main chain. Are more preferred.

  Examples of the thermoplastic elastomer having a urethane bond in at least a part of the main chain include a polyurethane elastomer. The polyurethane elastomer is preferably an elastomer having a urethane bond in the hard segment in the main chain, has a urethane bond in the hard segment in the main chain, and has an ether bond or an ester bond or both in the soft segment in the main chain. Are more preferred.

  Examples of the thermoplastic elastomer having an imide bond in at least a part of the main chain include a polyimide urethane elastomer. The polyimide elastomer is preferably an elastomer having an imide bond in a hard segment in the main chain, and more preferably having an imide bond in a hard segment in the main chain and having a urethane bond in a soft segment in the main chain.

  The thermoplastic elastomer preferably has a melting temperature of 250 ° C. or lower, more preferably 220 ° C. or lower. Here, the melting temperature refers to a melting point in the case of a thermoplastic elastomer having a melting point, and refers to a flow start temperature in the case of a thermoplastic elastomer having no melting point. Specifically, the melting point of the thermoplastic elastomer is determined by measuring the endothermic peak temperature of the DSC curve obtained by performing differential operation calorimetry (DSC) on the thermoplastic elastomer at a temperature rising rate of 10 ° C./min from room temperature under a nitrogen atmosphere. And The flow start temperature is a temperature at which the sample starts to flow when measurement is performed at a temperature rising rate of 3 ° C./min and a load of 490 N (50 kgf) in a Koka flow tester.

  The thermoplastic elastomer is preferably a polyester elastomer, a polyamide elastomer or a polyurethane elastomer, more preferably a polyester elastomer or a polyurethane elastomer, and further preferably a polyester elastomer.

As such a thermoplastic elastomer, an appropriately synthesized one may be used, or a commercially available one may be used. Further, two or more kinds of a plurality of grades or different thermoplastic elastomers can be used.
When two or more kinds of thermoplastic elastomers are used in combination, the combination of the thermoplastic elastomers is not particularly limited, and is appropriately determined.

  The content of the thermoplastic elastomer is preferably 20 to 100% by mass, more preferably 30 to 100% by mass, and still more preferably 40 to 100% by mass based on 100% by mass of the base elastomer.

  The base elastomer used in the present invention can be used by mixing an arbitrary resin or the like in addition to the thermoplastic elastomer. Examples of the resin that can be mixed include a polyolefin resin, rubber, and an elastomer. Specifically, polyethylene (PE), polypropylene (PP), ethylene vinyl acetate resin (EVA), ethylene-ethyl acrylate copolymer resin (EEA), ethylene-methyl acrylate copolymer resin (EMA), or a resin modified with an acid And polyolefin resins such as acid-modified resins. Examples of the rubber include acrylic rubber, nitrile rubber, chloroprene rubber, and chlorinated polyethylene. The elastomer is not particularly limited as long as it is other than the above-mentioned thermoplastic elastomer. For example, a styrene-based elastomer or an olefin-based elastomer can be used.

  The above-mentioned polyolefin resin is not particularly limited as long as it is generally used. For example, as the polyethylene resin, a homopolymer composed only of ethylene, high-density polyethylene (HDPE), low-density polyethylene (LDPE), ultra-high-molecular-weight polyethylene (UHMW-PE), linear low-density polyethylene (LLDPE), Each resin of low density polyethylene (VLDPE) can be used. Among them, resins of linear low-density polyethylene, low-density polyethylene (preferably polymerized by a high-pressure method) or high-density polyethylene are preferable.

  The elastomer is not particularly limited as long as it is usually used. For example, as the styrene-based elastomer, a copolymer elastomer of a conjugated diene compound and an aromatic vinyl compound, or a hydrogenated product thereof can be used. The styrene-based elastomer is not particularly limited. For example, styrene-butylene-styrene block copolymer (SBS), styrene-isoprene-styrene block copolymer (SIS), styrene-ethylene-propylene-styrene block copolymer (SEPS), styrene-ethylene-ethylene-propylene-styrene block copolymer (SEEPS), styrene-ethylene-butylene-styrene block copolymer (SEBS), hydrogenated SBS, hydrogenated SIS, hydrogenated styrene-butadiene rubber (HSBR) and the like.

  Examples of the olefin elastomer include a mixture (TPO, TPV) of polypropylene (PP) and ethylene-propylene (EP) rubber, and a polypropylene resin having a controlled crystal structure.

  The (total) content of any of the above resins is not particularly limited, but is preferably from 0 to 80% by mass, more preferably from 0 to 70% by mass, based on 100% by mass of the base elastomer. ~ 60 mass% is more preferred. The reason is that heat resistance and appearance are impaired.

  In the present invention, the base elastomer may further contain an oil component and a plasticizer.

The oil component is not particularly limited, but includes an organic oil or a mineral oil.
Organic oils include soybean oil and epoxidized soybean oil, and mineral oils include paraffin oil and naphthenic oil.
The content of the oil is not particularly limited. When the base elastomer contains an oil, the content is preferably 0 to 50% by mass, more preferably 0 to 30% by mass, based on 100% by mass of the base elastomer. If the oil content is too large, it will bleed or the strength will decrease.

The plasticizer is not particularly limited, and includes various types commonly used for thermoplastic elastomers. For example, trialkyl trimellitate (C8, C10), pyromellitic acid ester plasticizer, phthalic acid ester plasticizer, adipic acid ester plasticizer, polyester plasticizer and the like can be mentioned.
The content of the plasticizer is not particularly limited, but when the resin contains a plasticizer, the content is preferably 0 to 50% by mass, more preferably 0 to 30% by mass based on 100% by mass of the base elastomer. . If the content of the plasticizer is too large, it bleeds or the strength is reduced.

  In the base elastomer, the content of each component is appropriately determined so that the total of each component such as an oil component and a plasticizer such as a thermoplastic elastomer and another resin is 100% by mass, and preferably the content is within the above range. Selected.

<Organic peroxide>
The organic peroxide generates a radical at least by thermal decomposition, and acts as a catalyst to cause a graft reaction by a radical reaction of the silane coupling agent to the base elastomer. In particular, when the reaction site of the silane coupling agent contains, for example, an ethylenically unsaturated group, a graft reaction by a radical reaction between the ethylenically unsaturated group and the base elastomer component (including a reaction for extracting hydrogen radicals from the base elastomer component) is performed. It works to make it happen.
The organic peroxide is not particularly limited as long as it generates a radical. For example, general formulas: R ¹ -OO-R ² , R ³ -OO-C (＝ O) R ⁴ , R ⁵ C A compound represented by (＝ O) —OO (C ＝ O) R ⁶ is preferable. Here, R ^{1 to} R ⁶ each independently represent an alkyl group, an aryl group or an acyl group. Of R ^{1 to} R ⁶ of each compound, those in which all are alkyl groups, or those in which any one is an alkyl group and the rest are acyl groups, are preferred.

  Such organic peroxides include, for example, dicumyl peroxide (DCP), di-tert-butyl peroxide, 2,5-dimethyl-2,5-di- (tert-butylperoxy) hexane, , 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-butyl peroxyisopropyl carbonate, diacetate Peroxide, lauroyl peroxide, it may be mentioned tert- butyl cumyl peroxide and the like. Among them, dicumyl peroxide, 2,5-dimethyl-2,5-di- (tert-butylperoxy) hexane, and 2,5-dimethyl-2 are preferable in terms of odor, coloring, and scorch stability. , 5-Di (tert-butylperoxy) hexyne-3 is preferred.

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

<Inorganic filler>
In the present invention, the inorganic filler is not particularly limited as long as the surface has a site capable of chemically bonding to a reaction site such as a silanol group of a silane coupling agent with a hydrogen bond or a covalent bond, or an intermolecular bond on its surface. It can be used without. Examples of the part of the inorganic filler that can chemically bond with the reaction part of the silane coupling agent include an OH group (OH group such as a hydroxyl group, a water molecule containing water or water of crystallization, an OH group such as a carboxy group), an amino group, and an SH group. Can be

  The inorganic filler is not particularly limited, for example, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, aluminum oxide, aluminum nitride, aluminum borate whisker, Metal hydrates such as hydrated aluminum silicate, hydrated magnesium silicate, basic magnesium carbonate, hydrotalcite, talc, and other compounds having a hydroxyl group or water of crystallization. Also, boron nitride, silica (crystalline silica, amorphous silica, etc.), carbon, clay, zinc oxide, tin oxide, titanium oxide, molybdenum oxide, antimony trioxide, silicone compounds, quartz, zinc borate, white carbon, Zinc borate, zinc hydroxy stannate, zinc stannate and the like can be mentioned.

  As the inorganic filler, a surface-treated inorganic filler surface-treated with a silane coupling agent or the like can be used. For example, as the silane coupling agent surface-treated inorganic filler, Kisuma 5L and Kisuma 5P (both are trade names, magnesium hydroxide, manufactured by Kyowa Chemical Industry Co., Ltd.) and the like are exemplified. Although the surface treatment amount of the inorganic filler with the silane coupling agent is not particularly limited, it is, for example, 3% by mass or less.

Among these inorganic fillers, at least one selected from the group consisting of silica, aluminum hydroxide, magnesium hydroxide, calcium carbonate and antimony trioxide is preferable, and silica is more preferable.
One type of inorganic filler may be used alone, or two or more types may be used in combination.

  When the inorganic filler is a powder, the average particle size of the inorganic filler is preferably from 0.2 to 10 μm, more preferably from 0.3 to 8 μm, still more preferably from 0.4 to 5 μm, particularly preferably from 0.4 to 3 μm. preferable. When the average particle size is within the above range, the effect of holding the silane coupling agent is high and the heat resistance is excellent. In addition, the inorganic filler does not easily undergo secondary agglomeration when mixed with the silane coupling agent, resulting in an excellent appearance. The average particle size is obtained by dispersing an inorganic filler in alcohol or water, and using an optical particle size measuring device such as a laser diffraction / scattering type particle size distribution measuring device.

<Silane coupling agent>
The silane coupling agent used in the present invention can chemically bond an inorganic filler with a grafting reaction site (group or atom) capable of performing a graft reaction on a base elastomer in the presence of a radical generated by decomposition of an organic peroxide. Any site may be used as long as it has at least a reaction site capable of reacting with a site and capable of silanol condensation (including a site generated by hydrolysis, such as a silyl ester group). Examples of such a silane coupling agent include silane coupling agents conventionally used in a silane crosslinking method.

  As the silane coupling agent, for example, a compound represented by the following general formula (1) can be used.

In the general formula (1), R _a11 is a group containing an ethylenically unsaturated group, and 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.

_Ra11 is a grafting reaction site, and is preferably a group containing an ethylenically unsaturated group. Examples of the group containing an ethylenically unsaturated group include a vinyl group, a (meth) acryloyloxyalkylene group, and a p-styryl group. Among them, a vinyl group is preferred.

R _b11 represents an aliphatic hydrocarbon group, a hydrogen atom or Y ¹³ described later. Examples of the aliphatic hydrocarbon group include a monovalent aliphatic hydrocarbon group having 1 to 8 carbon atoms excluding an aliphatic unsaturated hydrocarbon group. R _b11 is preferably below ^{Y 13.}

Y ¹¹ , Y ¹² and Y ¹³ represent a reactive site capable of silanol condensation (hydrolyzable organic group). Examples thereof include an alkoxy group having 1 to 6 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, and an acyloxy group having 1 to 4 carbon atoms, and an alkoxy group is preferable. Specific examples of the hydrolyzable organic group include methoxy, ethoxy, butoxy, acyloxy and the like. Among them, methoxy or ethoxy is more preferable from the viewpoint of the reactivity of the silane coupling agent.

The silane coupling agent is preferably a silane coupling agent having a high hydrolysis rate, and 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. A ring agent or a silane coupling agent in which at least one of Y ¹¹ , Y ¹² and Y ¹³ is a methoxy group.

Specific examples of the silane coupling agent include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltributoxysilane, vinyldimethoxyethoxysilane, vinyldimethoxybutoxysilane, vinyldiethoxybutoxysilane, allyltrimethoxysilane, and allyltrimethoxysilane. Examples thereof include vinyl silanes such as ethoxy silane and vinyl triacetoxy silane, and (meth) acryloxy silanes such as methacryloxy propyl trimethoxy silane, methacryloxy propyl triethoxy silane, and methacryloxy propyl methyl dimethoxy silane.
Among the above silane coupling agents, a silane coupling agent having a vinyl group and an alkoxy group at a terminal is more preferable, and at least one of vinyltrimethoxysilane and vinyltriethoxysilane is particularly preferable.

  One type of silane coupling agent may be used alone, or two or more types may be used in combination. Further, it may be used as it is, or may be diluted with a solvent or the like.

<Silanol condensation catalyst>
The silanol condensation catalyst has a function to cause the silane coupling agent grafted to the base elastomer to undergo a condensation reaction in the presence of moisture. Based on the function of the silanol condensation catalyst, the base elastomers are cross-linked via the silane coupling agent. As a result, a heat-resistant silane-crosslinked thermoplastic elastomer molded article having excellent heat resistance can be obtained.

  Examples of the silanol condensation catalyst used in the present invention include organotin compounds, metallic soaps, platinum compounds and the like. Typical silanol condensation catalysts include, for example, dibutyltin dilaurate, dioctyltin dilaurate, dibutyltin dioctate, 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. Of these, organic tin compounds such as dibutyltin dilaurate, dioctyltin dilaurate, dibutyltin dioctate, and dibutyltin diacetate are particularly preferred.

<Carrier>
The silanol condensation catalyst is used after being mixed with a carrier, if desired. Such a carrier is not particularly limited, but the elastomer, resin, or rubber described for the base elastomer can be used. This carrier is preferably melt-kneaded with the above-mentioned base elastomer, particularly the above-mentioned thermoplastic elastomer, from the viewpoint of compatibility with the silane masterbatch. For example, as the carrier, it is preferable to use one or more kinds of thermoplastic elastomers or resins used for the silane masterbatch (base elastomer), and it is more preferable to use the thermoplastic elastomer used for the base elastomer. In the present invention, in the case where a resin or rubber is used in addition to the elastomer in addition to the case where the elastomer is used as the carrier, the carrier may be referred to as a carrier elastomer for convenience.

<Additives>
The heat-resistant silane-crosslinked thermoplastic elastomer molded article is used in various kinds of additives generally used in electric wires, electric cables, electric cords, sheets, foams, tubes, and pipes, so long as the effects of the present invention are not impaired. May be contained. Examples of such additives include a crosslinking aid, an antioxidant, a lubricant, a metal deactivator, a filler (including a flame retardant (auxiliary) agent), and a brominated flame retardant.

  The cross-linking aid refers to one that forms a partially cross-linked structure with the base elastomer in the presence of the organic peroxide. Examples include (meth) acrylate compounds such as polypropylene glycol diacrylate and trimethylolpropane triacrylate, allyl compounds such as triallyl cyanurate, and polyfunctional compounds such as maleimide compounds and divinyl compounds.

  Although it does not specifically limit as an antioxidant, For example, an amine antioxidant, a phenol antioxidant, a sulfur antioxidant, etc. are mentioned. Examples of the amine antioxidant include 4,4′-dioctyldiphenylamine, N, N′-diphenyl-p-phenylenediamine, and a polymer of 2,2,4-trimethyl-1,2-dihydroquinoline. . Examples of the phenol antioxidant include pentaerythrityl-tetrakis (3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate) and octadecyl-3- (3,5-di-tert-butyl). -4-hydroxyphenyl) propionate, 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene and the like. Examples of the sulfur antioxidant include bis (2-methyl-4- (3-n-alkylthiopropionyloxy) -5-tert-butylphenyl) sulfide, 2-mercaptobenzimidazole and its zinc salt, pentaerythritol-tetrakis (3-lauryl-thiopropionate) 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, based on 100 parts by mass of the base elastomer.

  Examples of the metal deactivator include N, N'-bis (3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyl) hydrazine, 3- (N-salicyloyl) amino-1,2,4 -Triazole, 2,2'-oxamidobis (ethyl 3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate) and the like.

  Flame retardant (auxiliary) agents (excluding the following brominated flame retardants), fillers include carbon, clay, zinc oxide, tin oxide, titanium oxide, magnesium oxide, molybdenum oxide, antimony trioxide, silicone compounds, quartz, Examples include talc, calcium carbonate, magnesium carbonate, zinc borate, and white carbon. These fillers may be used when mixing a silane coupling agent as a filler, or may be added to a carrier.

  Examples of the lubricant include hydrocarbons, siloxanes, fatty acids, fatty acid amides, esters, alcohols, and metallic soaps. These lubricants should be added to the carrier.

The brominated flame retardant used in the present invention is not particularly limited as long as it is used as a flame retardant. For example, brominated ethylene bisphthalimide and its derivatives, bisbrominated phenylterephthalamide and its derivatives, brominated bisphenol ( For example, tetrabromobisphenol A) and its derivatives, 1,2-bis (bromophenyl) ethane and its derivatives, polybromodiphenyl ether (for example, decabromodiphenyl ether) and its derivatives, and polybromobiphenyl (for example, tribromophenyl) and its derivatives Organic bromine-containing flame retardants such as derivatives, hexabromocyclododecane, brominated polystyrene, and hexabromobenzene can be used. Here, the “derivative” refers to a compound having an organic group such as an alkyl group as a substituent, or a compound having a different number of bromine atoms.
Among these, from the viewpoint of safety, brominated bisphenol (particularly, tetrabromobisphenol A), brominated polystyrene, brominated ethylene bisphthalimide represented by the following structural formula 1, and 1,2 represented by the following structural formula 2 -Bis (bromophenyl) ethane derivatives are preferable, and brominated ethylenebisphthalimide represented by the following structural formula 1 and 1,2-bis (bromophenyl) ethane derivatives represented by the following structural formula 2 are more preferable.
In the structural formula 2, n is independently an integer of 1 to 5, preferably an integer of 3 to 5.

Next, the production method of the present invention will be specifically described.
The method for producing a heat-resistant silane-crosslinked thermoplastic elastomer molded article of the present invention includes the following steps (a) to (c).
The silane masterbatch of the present invention is produced by the following step (a), and the masterbatch mixture of the present invention is produced by the following steps (a) and (b).

(A) 0.01 to 0.5 parts by mass of an organic peroxide and 0.5 to 300 parts by mass of an inorganic filler with respect to 100 parts by mass of a base elastomer containing a thermoplastic elastomer other than styrene and olefin. (B) preparing a silane masterbatch by melt-kneading 1 to 15 parts by mass of a silane coupling agent at a temperature not lower than the decomposition temperature of the organic peroxide; and (b) preparing a silane masterbatch obtained in the step (a). (C) a step of molding the silanol condensation catalyst after mixing with the catalyst, and a step of cross-linking the molded article obtained in the step (b) by bringing it into contact with moisture. Here, mixing means obtaining a uniform mixture. Say.

  In the step (a), the amount of the organic peroxide is 0.01 to 0.5 part by mass, preferably 0.05 to 0.3 part by mass, based on 100 parts by mass of the base elastomer. If the compounding amount of the organic peroxide is less than 0.01 parts by mass, the graft reaction does not proceed, the unreacted silane coupling agents condense or the unreacted silane coupling agent volatilizes, and the heat resistance is sufficient. May not be available. On the other hand, if it exceeds 0.5 parts by mass, many of the base elastomer components are directly crosslinked by a side reaction to form bumps, which may cause poor appearance. In addition, a silane master batch having excellent extrudability may not be obtained. That is, by setting the compounding amount of the organic peroxide within this range, a graft reaction can be performed within an appropriate range, and a silane master excellent in extrudability without generating gel-like bumps (agglomerates). Batches and the like can be obtained.

  The amount of the inorganic filler is 0.5 to 300 parts by mass, preferably 1 to 150 parts by mass, based on 100 parts by mass of the base elastomer. If the blending amount of the inorganic filler is less than 0.5 part by mass, the graft reaction of the silane coupling agent becomes non-uniform, and it may not be possible to impart excellent heat resistance to the heat-resistant silane-crosslinked thermoplastic elastomer molded article. Further, the graft reaction of the silane coupling agent becomes non-uniform, and the appearance of the heat-resistant silane crosslinked thermoplastic elastomer molded article may be deteriorated. On the other hand, if it exceeds 300 parts by mass, the load during molding or kneading becomes extremely large, and secondary molding may be difficult. In addition, heat resistance and appearance may be reduced.

The compounding amount of the silane coupling agent is 1 to 15 parts by mass with respect to 100 parts by mass of the base elastomer. If the compounding amount of the silane coupling agent is less than 1.0 part by mass, the crosslinking reaction does not sufficiently proceed, and excellent heat resistance may not be exhibited. In addition, when molding is performed together with the silanol condensation catalyst, lumps may occur, and when the extruder is stopped, many lumps may occur. As a result, appearance defects occur. On the other hand, if it exceeds 15.0 parts by mass, the silane coupling agent cannot be completely adsorbed on the surface of the inorganic filler, and the silane coupling agent volatilizes during kneading, which is not economical. In addition, the silane coupling agent that does not adsorb may be condensed, and the heat-resistant silane crosslinked thermoplastic elastomer molded article may be crosslinked and burnt, resulting in deterioration in appearance.
From the above viewpoint, the compounding amount of the silane coupling agent is preferably 3 to 12.0 parts by mass, more preferably 4 to 12.0 parts by mass, based on 100 parts by mass of the base elastomer.

  The amount of the silanol condensation catalyst is not particularly limited, and is preferably 0.0001 to 0.5 part by mass, more preferably 0.001 to 0.2 part by mass, based on 100 parts by mass of the base elastomer. When the amount of the silanol condensation catalyst is within the above range, the crosslinking reaction by the condensation reaction of the silane coupling agent tends to proceed almost uniformly, and the heat resistance, appearance and physical properties of the heat-resistant silane crosslinked thermoplastic elastomer molded article are excellent. , Productivity also improves. That is, if the blending amount of the silanol condensation catalyst is too small, the crosslinking by the condensation reaction of the silane coupling agent becomes difficult to proceed, and the heat resistance of the heat-resistant silane crosslinked thermoplastic elastomer molded body is not readily improved, and the productivity is reduced. Or the crosslinking may be non-uniform. On the other hand, if the content is too large, the silanol condensation reaction proceeds very quickly, and partial gelation may occur, which may lower the appearance. Further, the physical properties of the heat-resistant silane crosslinked thermoplastic elastomer molded article (resin) may be reduced.

In the present invention, "melt and mix the base elastomer, the organic peroxide, the inorganic filler and the silane coupling agent" does not specify the mixing order at the time of melt mixing, but in any order. Also means good. The mixing order in the step (a) is not particularly limited. In the present invention, the inorganic filler is preferably used in a mixture with a silane coupling agent. That is, in the present invention, it is preferable that the above components are (melted) mixed in the following steps (a-1) and (a-2).
Step (a-1): Step of preparing a mixture by mixing at least an inorganic filler and a silane coupling agent Step (a-2): All or one of the mixture obtained in Step (a-1) and the base elastomer And melting the mixture at a temperature equal to or higher than the decomposition temperature of the organic peroxide in the presence of the organic peroxide.

The step (a-2) includes "an aspect in which the entire amount (100 parts by mass) of the base elastomer is blended" and "an aspect in which a part of the base elastomer is blended". When a part of the base elastomer is blended in the step (a-2), the remaining part of the base elastomer is preferably blended in the step (b).
In the present invention, "part of the base elastomer" refers to a resin used in the step (a-2) of the base elastomer, and a part of the base elastomer itself (having the same composition as the base elastomer), And a part of the base elastomer (for example, the total amount of a specific resin component among a plurality of resin components).
In addition, the “residue of the base elastomer” refers to the remaining resin of the base elastomer except for a part used in the step (a-2). Specifically, the remaining resin of the base elastomer itself, The remainder of the constituent components and the remaining components of the base elastomer are referred to.
When a part of the base elastomer is blended in the step (a-2), 100 parts by mass of the base elastomer in the steps (a) and (b) are mixed in the steps (a-2) and (b). The total amount of base elastomer used.
Here, when the remainder of the base elastomer is blended in the step (b), the base elastomer is preferably blended in the step (a-2) in an amount of 80 to 99% by mass, more preferably 85 to 95% by mass, In the step (b), preferably 1 to 20% by mass, more preferably 5 to 15% by mass is blended.

In the present invention, the silane coupling agent is preferably premixed with the inorganic filler as described above (step (a-1)).
The method of mixing the inorganic filler and the silane coupling agent is not particularly limited, and examples thereof include a mixing method such as a wet treatment and a dry treatment. Specifically, a wet treatment in which the silane coupling agent is dispersed in a state in which the inorganic filler is dispersed in a solvent such as alcohol or water, or in an untreated inorganic filler, or in advance with stearic acid, oleic acid, a phosphate ester or Dry treatment in which a silane coupling agent is added with heating or non-heating to an inorganic filler whose part has been surface-treated with a silane coupling agent and mixed, and both of them are given. In the present invention, a dry treatment in which a silane coupling agent is added to or mixed with an inorganic filler, preferably a dried inorganic filler, with or without heating is preferred.
The silane coupling agent premixed in this manner exists so as 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. Thereby, volatilization of the silane coupling agent at the time of subsequent melt mixing can be reduced. In addition, it is possible to prevent the silane coupling agent that does not adsorb or bind to the inorganic filler from condensing and making melt-kneading difficult. Further, a desired shape can be obtained at the time of extrusion molding.

As such a mixing method, the inorganic filler and the silane coupling agent are preferably mixed at a temperature lower than the decomposition temperature of the organic peroxide, preferably at room temperature (25 ° C.), for several minutes to several hours, in a dry or wet manner. After (dispersion), a method of melt-mixing the mixture and the base elastomer in the presence of an organic peroxide may be mentioned. This mixing is preferably performed by a mixer-type kneader such as a Banbury mixer or a kneader. By doing so, an excessive crosslinking reaction between the base elastomer components can be prevented, and the appearance becomes excellent.
In this mixing method, the base elastomer may be present as long as the temperature below the decomposition temperature is maintained. In this case, it is preferable that the metal oxide and the silane coupling agent are mixed together with the base elastomer at the above temperature (step (a-1)) and then melt-mixed.

The method of mixing the organic peroxide is not particularly limited, as long as it is present when the mixture and the base elastomer are melt-mixed. The organic peroxide, for example, may be mixed simultaneously with the inorganic filler or the like, or may be mixed at any of the mixing stages of the inorganic filler and the silane coupling agent, to a mixture of the inorganic filler and the silane coupling agent They may be mixed. For example, the organic peroxide may be mixed with the inorganic filler after being mixed with the silane coupling agent, or may be separately mixed with the inorganic filler separately from the silane coupling agent. Depending on the production conditions, only the silane coupling agent may be mixed with the inorganic filler, and then the organic peroxide may be mixed.
The organic peroxide may be mixed with other components, or may be used alone.

  In the method of mixing the inorganic filler and the silane coupling agent, in wet mixing, since the binding force between the silane coupling agent and the inorganic filler is increased, volatilization of the silane coupling agent can be effectively suppressed, The silanol condensation reaction may be difficult to proceed. On the other hand, in the dry mixing, the silane coupling agent is easily volatilized, but the bonding force between the inorganic filler and the silane coupling agent is relatively weak, so that the silanol condensation reaction easily proceeds easily.

  In a preferred production method of the present invention, then, the obtained mixture, all or a part of the base elastomer, and the remaining components not mixed in step (a-1) are mixed in the presence of an organic peroxide. Melt kneading while heating to a temperature equal to or higher than the decomposition temperature of the organic peroxide (step (a-2)).

In the step (a-2), the temperature at which the above components are melt-mixed (also referred to as melt-kneading or kneading) is equal to or higher than the decomposition temperature of the organic peroxide, preferably the decomposition temperature of the organic peroxide + (25 to 110). It is a temperature of ° C. This decomposition temperature is preferably set after the base elastomer component is melted. At the mixing temperature, the components are melted, the organic peroxide is decomposed and acts, and the necessary silane graft reaction proceeds sufficiently in the step (a-2). Other conditions, for example, the mixing time can be set as appropriate.
The mixing method is not particularly limited as long as it is a method usually used for rubber, plastic, and the like. The mixing device is appropriately selected according to, for example, the blending amount of the inorganic filler. As a kneading device, a single-screw extruder, a twin-screw extruder, a roll, a Banbury mixer, various kneaders, or the like is used. In view of the dispersibility of the base elastomer component and the stability of the crosslinking reaction, a closed mixer such as a Banbury mixer or various kneaders is preferable.
When such an inorganic filler is usually mixed in an amount exceeding 100 parts by mass with respect to 100 parts by mass of the base elastomer, kneading is performed by a continuous kneader, a pressure kneader, or a closed mixer such as a Banbury mixer. Is good.
The method for mixing the base elastomer is not particularly limited. For example, a base elastomer prepared by mixing in advance may be used, or each component, for example, the above-mentioned thermoplastic elastomer, another resin, an oil component, and a plasticizer may be separately mixed.

  In the present invention, the above components can be melt-mixed at once. In this case, the conditions of the melt-mixing are not particularly limited, but the conditions of the step (a-2) can be adopted. In this case, a part or all of the silane coupling agent is adsorbed or bonded to the inorganic filler during melt mixing.

  In the step (a), particularly in the step (a-2), it is preferable to knead the above-mentioned components without substantially mixing the silanol condensation catalyst. Thereby, the condensation reaction of the silane coupling agent can be suppressed, the mixture can be easily melt-mixed, and a desired shape can be obtained during extrusion molding. Here, "substantially not mixed" does not exclude the inevitably present silanol condensation catalyst, but exists to such an extent that the above-mentioned problem due to silanol condensation of the silane coupling agent does not occur. Also means good. For example, in the step (a-2), the silanol condensation catalyst may be present as long as it is 0.01 part by mass or less based on 100 parts by mass of the base elastomer.

In the step (a), the compounding amount of other resins and the above additives which can be used in addition to the above components is appropriately set within a range not to impair the object of the present invention.
In the step (a), the above-mentioned additives, particularly the antioxidant and the metal deactivator, may be mixed in any step or with the component, but the silane coupling agent mixed with the inorganic filler is added to the base elastomer. It is preferable to mix with a carrier so as not to hinder the graft reaction.
In the step (a), particularly in the step (a-2), it is preferable that the crosslinking aid is not substantially mixed. If the crosslinking aid is not substantially mixed, the organic peroxide hardly causes a crosslinking reaction between the base elastomer components during the melt mixing, resulting in an excellent appearance. Further, a graft reaction of the silane coupling agent to the base elastomer hardly occurs, and the heat resistance is excellent. Here, “not substantially mixed” does not exclude the inevitable cross-linking aid, but means that it may be present to such an extent that the above-mentioned problem does not occur.

  Thus, the step (a) is performed to prepare a silane masterbatch (also referred to as silane MB) used for producing a masterbatch mixture. The silane MB contains a silane crosslinkable thermoplastic elastomer in which a silane coupling agent is grafted on the base elastomer to such an extent that it can be molded in the step (b) described below.

Next, in the production method of the present invention, a step (b) of molding after mixing the silane MB obtained in the step (a) and the silanol condensation catalyst is performed.
In the present invention, the step (b) preferably includes the following steps (b-1) and (b-2).
Step (b-1): Step of preparing a catalyst master batch by mixing a silanol condensation catalyst and a carrier Step (b-2): Step of mixing and mixing the obtained silane master batch and the catalyst master batch

  In the step (b-1), as described above, the remainder of the base elastomer or another elastomer different from the base elastomer can be used as the carrier. In the present invention, it is preferable to use an elastomer different from the base elastomer.

  When a part of the base elastomer is melt-mixed in the step (a-2), the remainder of the base elastomer as a carrier is melt-mixed with a silanol condensation catalyst to prepare a catalyst masterbatch (also referred to as catalyst MB). It is preferable to use the catalyst MB (step (b-1)). In addition, other elastomers and the like can be used in addition to the rest of the base elastomer.

In the step (b-1), the mixing ratio of the remainder of the elastomer as a carrier and the silanol condensation catalyst is not particularly limited, but is preferably set so as to satisfy the above-mentioned compounding amount in the step (a).
Mixing may be any method as long as it can be uniformly mixed, and examples include mixing performed under melting of a resin (melt mixing). The melt mixing can be performed in the same manner as the melt mixing in the step (a-2). For example, the mixing can be performed at a temperature of 80 to 250 ° C, more preferably 100 to 240 ° C. Other conditions, for example, the mixing time can be set as appropriate.
The catalyst MB thus prepared is a mixture of a silanol condensation catalyst, a carrier elastomer and optionally a filler.

When all of the resin is melt-mixed in the step (a-2), a silanol condensation catalyst itself or a mixture of another elastomer or the like as a carrier and a silanol condensation catalyst (step (b-1). The mixing method with the silanol condensation catalyst is the same as the mixing method in the step (b-1) for preparing the catalyst MB.
The compounding amount of the carrier elastomer is preferably 1 to 60 parts by mass with respect to 100 parts by mass of the base elastomer, in that the graft reaction can be promoted in the step (a-2) and that there is hardly any bumps during molding. , More preferably 2 to 50 parts by mass, still more preferably 2 to 40 parts by mass.

In the production method of the present invention, a silane MB and a silanol condensation catalyst (a silanol condensation catalyst itself, a prepared catalyst MB, or a mixture of a silanol condensation catalyst and a carrier elastomer) are mixed.
The mixing method may be any mixing method as long as a uniform mixture can be obtained as described above. For example, the mixing is basically the same as the melt mixing in the step (a-2). There are resin components whose melting points cannot be measured by DSC or the like, for example, elastomers, but kneading is performed at a temperature at which at least one component of the base elastomer and the carrier is melted. The melting temperature is appropriately selected according to the melting temperature of the base elastomer or the carrier, and is, for example, preferably 80 to 250 ° C, more preferably 100 to 240 ° C. Other conditions, for example, mixing (kneading) time can be appropriately set.
In step (b), in order to avoid a silanol condensation reaction, it is preferable that the silane MB and the silanol condensation catalyst are not kept at a high temperature for a long time in a mixed state.

  In the step (b), the silane MB and the silanol condensation catalyst may be mixed, and the silane MB and the catalyst MB are preferably melt-mixed.

  In the present invention, the silane MB and the silanol condensation catalyst can be dry-blended before being melt-mixed. The method and conditions of the dry blending are not particularly limited, and include, for example, dry mixing in step (a-1) and its conditions. By this dry blending, a master batch mixture containing silane MB and a silanol condensation catalyst is obtained.

  In the step (b), an inorganic filler may be used. In this case, the amount of the inorganic filler is not particularly limited, but is preferably 350 parts by mass or less based on 100 parts by mass of the carrier. If the amount of the inorganic filler is too large, the silanol condensation catalyst is difficult to disperse, and the crosslinking is difficult to progress. On the other hand, if the amount of the inorganic filler is too small, the degree of cross-linking of the molded article is reduced, and sufficient heat resistance may not be obtained.

  In the present invention, the mixing of the steps (a) and (b) can be performed simultaneously or continuously.

In the step (b), the mixture thus obtained is molded.
In this molding step, it is sufficient that the mixture can be molded, and a molding method and molding conditions are appropriately selected according to the form of the heat-resistant product of the present invention. Examples of the molding method include extrusion molding using an extruder, extrusion molding using an injection molding machine, and molding using another molding machine. Extrusion is preferred when the heat-resistant product of the present invention is an electric wire or an optical fiber cable.

In the step (b), the molding step can be performed simultaneously or continuously with the mixing step. That is, as one embodiment of the melt mixing in the mixing step, there is an embodiment in which the forming raw materials are melt mixed at the time of melt molding, for example, at the time of, or immediately before, extrusion molding. For example, pellets such as a dry blend may be mixed at room temperature or high temperature and introduced into a molding machine (melt mixing), or they may be mixed and melt-mixed, then pelletized again, and introduced into a molding machine. Is also good. More specifically, a series of steps of melt-kneading a mixture (molding material) of silane MB and a silanol condensation catalyst in a coating apparatus, and then extruding and coating the outer peripheral surface of a conductor or the like to form a desired shape. Can be adopted.
In this way, a silane masterbatch and a silanol condensation catalyst are dry-blended to prepare a masterbatch mixture, and the masterbatch mixture is introduced into a molding machine and molded to form a heat-resistant silane crosslinkable thermoplastic elastomer composition. The body is obtained.

Here, the molten mixture of the master batch mixture contains silane crosslinkable thermoplastic elastomers having different crosslinking methods. In this silane crosslinkable thermoplastic elastomer, the reaction site of the silane coupling agent may be bonded or adsorbed to the inorganic filler, but is not silanol-condensed as described later. Therefore, the silane crosslinkable thermoplastic elastomer is based on a silane crosslinkable thermoplastic elastomer in which a silane coupling agent bonded or adsorbed to an inorganic filler is grafted to the base elastomer, and a silane coupling agent not bonded or adsorbed to the inorganic filler. A silane crosslinkable thermoplastic elastomer grafted to the elastomer. Further, the silane crosslinkable thermoplastic elastomer may have a silane coupling agent to which an inorganic filler is bonded or adsorbed and a silane coupling agent to which an inorganic filler is not bonded or adsorbed. Further, it may contain a base elastomer component that has not reacted with the silane coupling agent.
As described above, the silane crosslinkable thermoplastic elastomer is an uncrosslinked body in which the silane coupling agent has not been subjected to silanol condensation. In practice, when melt-mixed in step (b), partial crosslinking (partial crosslinking) is inevitable, but at least the moldability of the resulting heat-resistant silane-crosslinkable thermoplastic elastomer composition at the time of molding is low. Shall be retained.
Like the above mixture, the molded article obtained in the step (b) is in a partially crosslinked state in which the crosslinkability cannot be avoided, but retains the moldability that can be molded in the step (b). Therefore, the heat-resistant silane-crosslinked thermoplastic elastomer molded article of the present invention is formed into a crosslinked or finally crosslinked molded article by performing the step (c).

In the method for producing a heat-resistant silane-crosslinked thermoplastic elastomer molded article of the present invention, a step (c) of bringing the molded article obtained in the step (b) into contact with water is performed. As a result, the reaction site of the silane coupling agent is hydrolyzed to silanol, and the hydroxyl groups of silanol are condensed by the silanol condensation catalyst present in the molded body to cause a crosslinking reaction. In this way, a heat-resistant silane crosslinked thermoplastic elastomer molded article in which the silane coupling agent is silanol-condensed and crosslinked can be obtained.
The processing itself of the step (c) can be performed by a usual method. Condensation between silane coupling agents proceeds only by storage at room temperature.
Therefore, in the step (c), there is no need to positively contact the molded body with water. In order to accelerate this crosslinking reaction, the molded article can be brought into contact with moisture. For example, a method of positively contacting with water, such as immersion in warm water, introduction into a wet heat tank, or exposure to high-temperature steam, can be adopted. At that time, pressure may be applied to make water permeate inside.

  Thus, the method for producing a heat-resistant silane-crosslinked thermoplastic elastomer molded article of the present invention is carried out, and a heat-resistant silane-crosslinked thermoplastic elastomer molded article is produced. This heat-resistant silane-crosslinked thermoplastic elastomer molded article contains a silane-crosslinked thermoplastic elastomer obtained by condensing a (silane-crosslinkable) thermoplastic elastomer through a silanol bond (siloxane bond). One form of this heat-resistant silane-crosslinked thermoplastic elastomer molded article contains a silane-crosslinked thermoplastic elastomer and an inorganic filler. Here, the inorganic filler may be bonded to the silane coupling agent of the silane crosslinked thermoplastic elastomer. Therefore, the present invention includes an embodiment in which a base elastomer containing a thermoplastic elastomer is crosslinked with an inorganic filler via a silanol bond. Specifically, in this silane-crosslinked thermoplastic elastomer, a plurality of silane-crosslinked thermoplastic elastomers are bonded or adsorbed to an inorganic filler by a silane coupling agent, and are bonded (crosslinked) via the inorganic filler and the silane coupling agent. The reaction site of the silane crosslinked thermoplastic elastomer and the silane coupling agent grafted on the silane crosslinkable thermoplastic elastomer is hydrolyzed and silanol-condensed with each other to form a silane crosslinked thermoplastic crosslinked via the silane coupling agent. At least an elastomer. In the silane crosslinked thermoplastic elastomer, a bond (crosslinking) via an inorganic filler and a silane coupling agent and a crosslink via a silane coupling agent may be mixed. Further, it may contain a resin component not reacted with the silane coupling agent and / or a silane crosslinkable thermoplastic elastomer which is not crosslinked.

The manufacturing method of the present invention can be expressed as follows.
A method for producing a heat-resistant silane-crosslinked thermoplastic elastomer molded article having the following steps (A), (B) and (C), wherein step (A) has the following steps (A1) to (A4). A method for producing a heat-resistant silane-crosslinked thermoplastic elastomer molded article.
Step (A): 0.01 to 0.5 parts by mass of an organic peroxide and 0.5 to 300 parts by mass of an inorganic filler based on 100 parts by mass of a base elastomer containing a thermoplastic elastomer other than styrene and olefin. Step (B) of mixing a mixture, 1 to 15 parts by mass of a silane coupling agent, and a silanol condensation catalyst to obtain a mixture: a step of molding the mixture obtained in Step (A) to obtain a molded body (C): a step of bringing the molded article obtained in the step (B) into contact with water to obtain a heat-resistant silane-crosslinked thermoplastic elastomer molded article (A1): a step of mixing at least an inorganic filler and a silane coupling agent (A2): a step of melting and mixing all or a part of the mixture obtained in the step (A1) and the resin at a temperature equal to or higher than the decomposition temperature of the organic peroxide in the presence of the organic peroxide; step (A3): Step (A4) of mixing a lanol condensation catalyst and an elastomer different from the base elastomer or the remainder of the base elastomer as a carrier: the molten mixture obtained in Step (A2) and the melt mixture obtained in Step (A3) Step of mixing with a mixture In the above method, step (A) corresponds to the mixing of steps (a) and (b), and step (B) corresponds to the molding step of step (b). Step (C) corresponds to step (c) above. In addition, the step (A1) corresponds to the step (a-1), the step (A2) corresponds to the step (a-2), and the steps (A3) and (A4) correspond to the step (b). Each corresponds.

Although the details of the reaction mechanism in the production method of the present invention are not yet clear, it is considered as follows.
In the present invention, a mixture containing a base elastomer containing a thermoplastic elastomer other than styrene-based and olefin-based elastomers, and an organic peroxide, an inorganic filler and a silane coupling agent in a specific ratio, the decomposition temperature of the organic peroxide or more When melt-kneading is performed, preferably, the inorganic filler and the silane coupling agent are preliminarily mixed and melt-mixed with the base elastomer or the like, and the silane coupling agent is bonded or adsorbed to the inorganic filler at a site where the chemical bonding is possible. It is considered that the silane coupling agent bonded or adsorbed to the inorganic filler in this way causes a graft reaction to the base elastomer. Further, it is considered that the occurrence of the graft reaction relatively suppressed the decomposition reaction and / or the crosslinking reaction of the base elastomer, thereby suppressing the deterioration of the appearance and the deterioration of the physical properties of the molded article.
In the above melt mixing, the silane coupling agent bonded or adsorbed to the inorganic filler by a weak bond (interaction by hydrogen bond, interaction between ions, partial charges or dipoles, operation by adsorption, etc.) It desorbs and undergoes a graft reaction to the base elastomer. The silane coupling agent thus graft-reacted then undergoes a condensation reaction (crosslinking reaction) at a silanol-condensable reaction site to form a crosslinked thermoplastic elastomer via silanol condensation. The heat resistance of the heat-resistant silane-crosslinked thermoplastic elastomer molded article obtained by this crosslinking reaction is increased, and a heat-resistant silane-crosslinked thermoplastic elastomer molded article that does not melt even at a high temperature can be obtained.
On the other hand, the silane coupling agent bonded to the inorganic filler by a strong bond (a chemical bond with a hydroxyl group or the like on the surface of the inorganic filler) is less likely to cause a condensation reaction in the presence of water with the silanol condensation catalyst, so that the bonding with the inorganic filler is difficult. Is held. For this reason, bonding (crosslinking) between the base elastomer and the inorganic filler via the silane coupling agent occurs. As a result, the adhesion between the base elastomer and the inorganic filler is strengthened, and a molded article having good mechanical strength and abrasion resistance and resistant to damage is obtained. In particular, a plurality of silane coupling agents can be bonded to the surface of one inorganic filler particle, and high mechanical strength can be obtained.
By molding these silane-grafted thermoplastic elastomers together with a silanol condensation catalyst, and then contacting with moisture, it is possible to obtain a heat-resistant silane-crosslinked thermoplastic elastomer molded article having high heat resistance and even oil resistance. Is estimated.

  In the present invention, based on 100 parts by mass of the base elastomer, 0.01 parts by mass or more of organic peroxide, preferably 0.03 parts by mass or more, and 0.5 part by mass or less, preferably 0.3 part by mass. By mixing in the following ratio, and further mixing the silane coupling agent in a ratio of 1 to 15 parts by mass in the presence of the inorganic filler, to obtain a heat-resistant silane-crosslinked thermoplastic elastomer molded article having high heat resistance. Can be.

The production method of the present invention provides products requiring heat resistance (including semi-finished products, parts and members), products requiring flexibility and rubber elasticity, products requiring strength, and flame retardancy. It can be applied to the manufacture of required components, components of products such as rubber materials, or members thereof. Therefore, the heat-resistant product of the present invention is such a product. In particular, it is preferable that the product is required to have flexibility, rubber elasticity and heat resistance.
At this time, the heat-resistant product may be a product containing a heat-resistant silane-crosslinked thermoplastic elastomer molded article, or may be a product composed of only a heat-resistant silane-crosslinked thermoplastic elastomer molded article.
Examples of the heat-resistant product of the present invention include electric wires such as heat-resistant flame-retardant insulated wires, coating materials for heat-resistant flame-retardant cables or optical fiber cables, materials for rubber-substituted wires and cables, and other heat-resistant and flame-retardant electric wire parts, and flame-resistant heat-resistant materials. A sheet, a flame-resistant heat-resistant film, and the like. In addition, power plugs, connectors, sleeves, boxes, tape bases, tubes, sheets, packings, cushioning materials, earthquake-proof materials, wiring materials used for internal and external wiring of electrical and electronic equipment, especially electric wires and optical fiber cables No. Examples of products requiring flexibility, rubber elasticity, and heat resistance include electric wires and cables for televisions and automobiles (particularly for brakes) among electric wires and optical fiber cables.

The production method of the present invention is suitably applied particularly to the production of electric wires and optical fiber cables among the above products, and can form these coating materials (insulators, sheaths).
When the heat-resistant product of the present invention is an extrusion-molded product such as an electric wire or an optical fiber cable, preferably, the molding material is melt-kneaded in an extruder (extrusion coating apparatus) and heat-resistant silane-crosslinkable crosslinked thermoplastic elastomer composition. , The heat-resistant silane-crosslinkable crosslinked thermoplastic elastomer composition is extruded to the outer periphery of a conductor or the like to cover the conductor or the like. Such heat-resistant products can be prepared by using a general-purpose extrusion coating device without using a special machine such as an electron beam cross-linking machine, even if a large amount of an inorganic filler is added to the heat-resistant silane-crosslinkable crosslinked thermoplastic elastomer composition. , Around the conductor, or by extrusion coating the tensile strength fiber around the vertically laid or twisted conductor. For example, a single wire or a stranded wire of soft copper can be used as the conductor. In addition to the bare wire, a tin-plated conductor or a conductor having an enamel-coated insulating layer can be used as the conductor. The thickness of the insulating layer (coating layer made of the heat-resistant silane-crosslinkable crosslinked thermoplastic elastomer composition of the present invention) 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 detail with reference to Examples, but the present invention is not limited to these Examples.
In Tables 1 and 2, numerical values relating to the blending amount in each example represent parts by mass unless otherwise specified.

Details of each compound shown in Tables 1 and 2 are shown below.
<Base elastomer>
“Hytrel 2401” (trade name, manufactured by Toray DuPont, polyester elastomer, hard segment: polyester, soft segment: polyether, melting point: 163 ° C.)
“Perprene P40H” (trade name, manufactured by Toyobo Co., Ltd., polyester elastomer, hard segment: polyester, soft segment: polyether, melting point: 172 ° C.)
"Rezamin P-2288" (trade name, manufactured by Dainichi Seika Kogyo Co., Ltd., polyurethane elastomer, hard segment: polyurethane, soft segment: polyether, flow start temperature: 170 ° C)
"Pebax 4033" (trade name, manufactured by Arkema, polyamide elastomer, hard segment: polyamide, soft segment: polyether, melting point: 160 ° C)
"Eraslen 401A" (trade name, manufactured by Showa Denko KK, chlorinated polyethylene, chlorine content 40% by mass)
"Evaflex EV180" (trade name, manufactured by Du Pont-Mitsui Chemicals, ethylene vinyl acetate resin, vinyl acetate (VA) content 33% by mass)
"Septon 4077" (trade name, manufactured by Kuraray Co., Ltd., styrene-based elastomer (SEPS), styrene content 30% by mass)
"Evolu SP1540" (trade name, product of Prime Polymer, polyolefin resin (LLDPE))
"Diana Process Oil PW90" (trade name, manufactured by Idemitsu Kosan Co., Ltd., paraffin oil)

<Inorganic filler>
"Aerosil 200V" (trade name, manufactured by Nippon Aerosil Co., Ltd., hydrophilic fumed silica)
"Magsee's FK621" (trade name, manufactured by Kamishima Chemical Co., Ltd., magnesium hydroxide)
"Heidilite H42S" (trade name, manufactured by Showa Denko KK, aluminum hydroxide)
"Softon 1200" (trade name, Bihoku Powder Chemical Industry Co., Ltd., calcium carbonate)

<Silane coupling agent>
"KBM1003" (trade name, manufactured by Shin-Etsu Chemical Co., Ltd., vinyltrimethoxysilane)
"KBE1003" (trade name, manufactured by Shin-Etsu Chemical Co., Ltd., vinyltriethoxysilane)

<Organic peroxide>
“Perhexa 25B” (trade name, manufactured by NOF CORPORATION, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexane, decomposition temperature: 149 ° C.)
"Park Mill D" (trade name, manufactured by NOF Corporation, dicumyl peroxide, decomposition temperature 151 ° C)
<Antioxidant>
"Irganox 1076" (trade name, manufactured by BASF, octadecyl 3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate)
<Silanol condensation catalyst>
"ADEKA STAB OT-1" (trade name, manufactured by ADEKA, dioctyltin dilaurate)

(Examples 1 to 9 and Comparative Examples 2 to 7)
In Examples 1 to 9 and Comparative Examples 2 to 7, 5% by mass of the base elastomer was used as a carrier of the catalyst MB.

  First, an inorganic filler and a silane coupling agent were put into a 10 L Henschel mixer manufactured by Toyo Seiki Co., Ltd. at the mass ratios shown in column A of Tables 1 and 2, and mixed at room temperature (25 ° C.) for 1 hour to obtain a powder mixture. I got Next, the powder mixture thus obtained, the components and the organic peroxides shown in column A of Tables 1 and 2 were mixed at a mass ratio shown in column A of Tables 1 and 2 in Japan. It is put into a roll 2L Banbury mixer, kneaded at a temperature higher than the decomposition temperature of the organic peroxide, specifically at 190 ° C. for 10 minutes, then discharged at a material discharge temperature of 190 ° C., and pelletized to obtain silane MB. Was. The obtained silane MB contains a silane crosslinkable thermoplastic elastomer obtained by grafting a silane coupling agent to a base elastomer.

  On the other hand, the carrier, the silanol condensation catalyst, and the antioxidant are melt-mixed with a Banbury mixer at 180 to 190 ° C at a mass ratio shown in column B of Table 1 and Table 2, and discharged at a material discharge temperature of 180 to 190 ° C. Then, the mixture was pelletized to obtain a catalyst MB. This catalyst MB is a mixture of a carrier and a silanol condensation catalyst.

Next, the silane MB and the catalyst MB were charged into a closed type ribbon blender, and were dry-blended at room temperature (25 ° C.) for 5 minutes to obtain a dry blend (master batch mixture). At this time, the mixing ratio between the silane MB and the catalyst MB is the mass ratio shown in Tables 1 and 2.
Next, the obtained dry blend was extruded with a screw having a ratio of L / D (the ratio of the effective screw length L to the diameter D) = 24 and a screw diameter of 30 mm (compression part screw temperature 170 ° C., head temperature 200 ° C.). ). While the dry blend was melt-mixed in this extruder, the single-core conductor (soft copper conductor, 1 piece / 0.8 mmφ) was coated on the outside to obtain a coated conductor having an outer diameter of 2.4 mmφ. The coated conductor was left for one day in an atmosphere at a temperature of 60 ° C. and a relative humidity of 95%.

  Thus, an electric wire having a coating layer made of a heat-resistant silane-crosslinked thermoplastic elastomer molded article on the outer peripheral surface of the conductor was produced. The heat-resistant silane-crosslinked thermoplastic elastomer molded article as the coating layer has the above-mentioned silane-crosslinked thermoplastic elastomer.

(Comparative Example 1)
The components shown in columns A and B of Table 2 were collectively charged into the Banbury mixer used in Example 1, and the temperature was higher than the decomposition temperature of peroxide, specifically, 190 ° C. for 10 minutes. After kneading, the mixture was produced at a material discharge temperature of 190 ° C. and pelletized. Next, the obtained pellets were introduced into the extruder (compression part screw temperature 170 ° C., head temperature 200 ° C.) used in Example 1, and melted in the extruder while a single-core conductor (soft copper conductor, /0.8 mmφ) to obtain a coated conductor having an outer diameter of 2.4 mmφ. The coated conductor was left in an atmosphere at a temperature of 60 ° C. and a relative humidity of 95% for one day to produce an electric wire.

  The following tests were performed on the manufactured electric wires, and the results are shown in Tables 1 and 2.

(1) Wire appearance test The appearance test was performed by observing the appearance of the manufactured wire.
The appearance was visually checked for the presence or absence of variation in the outer diameter of the electric wire and the state of the surface.
The outer diameter of the electric wire fluctuates and is unstable, the surface is rough (the surface has irregularities that can be visually confirmed continuously), or a large number of local protrusions are found. "C" indicates that the molding was not possible, and "B" indicates that the molding was possible, although the surface was slightly roughened and bumpy, but neither the outer diameter variation, the roughening nor the bumping was recognized. The sample having good appearance was designated as "A".

(2) Hot set test A hot set test was performed in accordance with JIS C 3660-2-1. However, the oven was set at 200 ° C. Specifically, when a load of 10 N / cm ² was applied to one end of a tubular piece obtained by extracting a conductor from a manufactured electric wire in an oven at 200 ° C. for 15 minutes, the cut piece was rejected. "C" and not cut, but "B" was obtained by elongating 60%, "A" was not cut and elongation was less than 60%, and "B" and "A" were accepted.

  As is clear from the results shown in Tables 1 and 2, Examples 1 to 9 all passed the wire appearance test and the hot set test. As described above, according to the present invention, an electric wire having a heat-resistant silane-crosslinked thermoplastic elastomer molded article having excellent heat resistance and appearance as a coating could be produced. Therefore, according to the present invention, it was found that the heat-resistant silane-crosslinked thermoplastic elastomer molded article having the above excellent properties can be produced with high productivity.

  On the other hand, Comparative Example 1 in which the above components were collectively melt-mixed failed the wire appearance test. Further, Comparative Example 2 in which the content of the inorganic filler was too small did not pass the hot set test. Comparative Example 3 in which the content of the inorganic filler was too large did not pass the electric wire appearance test. Comparative Example 4, which contained too little organic peroxide, failed the hot set test. Comparative Example 5, which contained too much organic peroxide, failed the wire appearance test. Comparative Example 6, in which the content of the silane coupling agent was too small, did not pass the hot setting test, and Comparative Example 7, in which the content of the silane coupling agent was too large, did not pass the wire appearance test.

Claims (12)

The base elastomer 100 parts by weight containing scan styrene-based and thermoplastic elastomer other than the olefin, and an organic peroxide 0.01 to 0.5 parts by weight of an inorganic filler 0.5 to 300 parts by weight, the A heat-resistant silane-crosslinked thermoplastic elastomer molded article having a grafting reaction site capable of performing a graft reaction on a base elastomer and 1 to 15 parts by mass of a silane coupling agent capable of binding or adsorbing with the inorganic filler is produced. Hits the,
Step (a-1): a step of preparing a mixture by mixing at least the inorganic filler and the silane coupling agent in the above-mentioned quantitative ratio,
Step (a-2): melt-kneading the mixture obtained in the step (a-1) and the base elastomer at a temperature not lower than the decomposition temperature of the organic peroxide in the presence of the organic peroxide. A step of preparing a silane master batch containing a silane crosslinkable thermoplastic elastomer by performing a graft reaction between the base elastomer and the silane coupling agent.
A step of having (a),
Shaping after mixing the pre Symbol step (a) silane masterbatch silanol condensation catalyst obtained by the (b),
Method for producing a heat resistant silane crosslinked thermoplastic elastomer molded body and a step (c) to crosslink with the previous SL molded body obtained in step (b) is contacted with water.   The method for producing a heat-resistant silane-crosslinked thermoplastic elastomer molded article according to claim 1, wherein the thermoplastic elastomer has at least one of an amide bond, a urethane bond, an ester bond, and an imide bond in a main chain. The step (b) comprises:
(B-1) a step of mixing a silanol condensation catalyst and a carrier to prepare a catalyst master batch;
(B-2) a step of molding after mixing the masterbatch and the catalyst masterbatch,
The method for producing a heat-resistant silane-crosslinked thermoplastic elastomer molded article according to claim 1, which has:   The heat-resistant silane according to any one of claims 1 to 3, wherein the inorganic filler contains at least one selected from the group consisting of silica, magnesium hydroxide, aluminum hydroxide, calcium carbonate, and antimony trioxide. A method for producing a crosslinked thermoplastic elastomer molded article.   The method for producing a heat-resistant silane-crosslinked thermoplastic elastomer molded article according to any one of claims 1 to 4, wherein the inorganic filler contains silica.   The method for producing a heat-resistant silane-crosslinked thermoplastic elastomer molded article according to any one of claims 1 to 5, wherein the content of the inorganic filler is 1 to 150 parts by mass with respect to 100 parts by mass of the base elastomer.   The heat-resistant silane-crosslinked thermoplastic elastomer molded article according to any one of claims 1 to 6, wherein the silane coupling agent includes at least one selected from the group consisting of vinyltrimethoxysilane and vinyltriethoxysilane. Production method.   The method for producing a heat-resistant silane-crosslinked thermoplastic elastomer molded article according to any one of claims 1 to 7, wherein the melt-kneading in the step (a) is performed by a closed mixer.   A heat-resistant silane-crosslinked thermoplastic elastomer molded article produced by the production method according to claim 1.   A heat-resistant product comprising the heat-resistant silane crosslinked thermoplastic elastomer molded article according to claim 9.   The heat-resistant product according to claim 10, wherein the heat-resistant silane-crosslinked thermoplastic elastomer molded article is a coating of an electric wire or an optical fiber cable. Based on 100 parts by mass of a base elastomer containing a thermoplastic elastomer other than styrene and olefin, 0.01 to 0.5 part by mass of an organic peroxide, 0.5 to 300 parts by mass of an inorganic filler, and a silane cup 1 to 15 parts by mass of a ring agent and a grafting reaction site capable of performing a graft reaction on the base elastomer, and used for producing a masterbatch mixture obtained by mixing a silanol condensation catalyst capable of binding or adsorbing with the inorganic filler. Silane master batch,
A mixture obtained by mixing at least the inorganic filler and the silane coupling agent in the above-described ratios and the base elastomer are melt-kneaded at a temperature equal to or higher than the decomposition temperature of the organic peroxide in the presence of the organic peroxide. And a silane crosslinkable thermoplastic elastomer obtained by a graft reaction between the base elastomer and the silane coupling agent.