JP2008239900A - Resin composition, resin molding made from the resin composition, and insulated electric wire covered with the resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition excellent in flame retardancy, mechanical properties, heat resistance and environmental adaptability, used for automobiles, electric/electronic appliances, etc., as a construction material of resin moldings or as an insulating coating material of insulated electric wires, and to provide a resin molding made from the resin composition, and insulated electric wires coated with the resin composition. <P>SOLUTION: This resin composition comprises 1-6 pts.mass phenolic antioxidant, 2-32 pts.mass imidazole-based antioxidant surface-treated with a silane coupling agent, and 60-200 pts.mass inorganic hydrate based on 100 pts.mass synthetic resins. The composition is good in flame retardancy, mechanical properties and heat resistance, and environmentally friendly, and thus can be used, for example, as an insulating coating material of insulated electric wires mounted on automobiles or electric/electronic appliances, or a construction material of parts or members. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a resin composition, a resin molded body made of the resin composition, and an insulated wire coated with the resin composition. More specifically, the present invention relates to an insulated wire coated with the resin composition used for automobiles, electrical / electronic devices, and the like.

  Various properties such as flame retardancy, mechanical properties, and heat resistance are required for resin compositions used in automobiles, electrical / electronic devices, etc. as insulation coating materials for resin molded products and insulated wires. A resin composition containing a polyvinyl chloride resin having excellent performance and low cost, a polyvinyl chloride compound, and a halogen flame retardant containing a chlorine atom or a bromine atom in a molecule was widely used. .

  On the other hand, since polyvinyl chloride resin contains halogen, it generates a large amount of smoke when incinerated in a fire, etc., or generates harmful gas such as halogen gas and dioxins depending on combustion conditions, causing environmental destruction. There was a problem of causing it. Therefore, in recent years, a resin composition (low halogen flame retardant resin composition) in which the blending amount of the halogen-based flame retardant is reduced, a flame retardant containing no halogen, and a resin composition composed of a resin (non-halogen flame retardant resin composition) Used). Such non-halogen flame retardant resin compositions are generally those based on polyolefins, ethylene copolymers, etc., which are highly filled with inorganic hydrates. Examples of inorganic hydrates include magnesium hydroxide and water. Aluminum oxide is used (see, for example, Patent Document 1 and Patent Document 2).

Japanese Patent Application Laid-Open No. 2002-226641 ([0006], [0023]) JP 2003-113276 A ([Claims], [0013])

  By the way, conventionally used polyvinyl chloride compound is kneaded, temperature at the time of molding process, and temperature when used as a member after molding process, compared with resin composition using polyolefin or ethylene copolymer. Since it is low, it was almost unnecessary to add an antioxidant for the purpose of imparting heat resistance to the compound. On the other hand, low halogen flame retardant resin compositions and non-halogen flame retardant resin compositions also have high temperatures during kneading and molding, and in particular, non-halogen flame retardant resin compositions contain a large amount of inorganic hydrates. Since the heat resistance of products tends to be low, the addition of an antioxidant has been considered essential for the purpose of improving this.

  On the other hand, the antioxidant added to the resin composition generally has a higher melting point or a higher molecular weight, and can impart higher heat resistance to the resin composition. However, the resin composition is kneaded and molded. For those that do not melt at the temperature, it becomes difficult to disperse in the resin composition, so the compatibility with the resin composition is poor, the effect of imparting heat resistance to the resin composition is not seen, and by aggregation Problems such as a decrease in mechanical properties of the resin composition and an increase in the difference in mechanical properties before and after the heat resistance test have occurred. This is also pointed out in “Japan Rubber Association Journal Vol. 63, No. 10, p. 630” and the like.

  The present invention has been made in view of the above-mentioned problems, and a resin composition used for an automobile, an electric / electronic device, etc. as an insulating coating material for a resin molded body or an insulated wire, mechanically before and after a heat resistance test. Resin composition comprising excellent flame retardancy, mechanical properties, heat resistance, and low environmental impact when disposed of by landfill, incineration, etc. The object is to provide a molded body and an insulated wire coated with the resin composition.

  In order to solve the above-mentioned problem, the resin composition according to claim 1 of the present invention is (b) 1 to 6 parts by mass of a phenolic antioxidant, c) 2 to 32 parts by mass of an imidazole antioxidant surface-treated with a silane coupling agent, and (d) 60 to 200 parts by mass of an inorganic hydrate.

  The resin composition according to claim 2 of the present invention is characterized in that, in the above-described claim 1, the (a) synthetic resins have a polyolefin resin as a main component.

  The resin composition according to claim 3 of the present invention is the resin composition according to claim 1 or 2, wherein the silane coupling agent has a vinyl group, a methacryloxy group, an acryloxy group, a mercapto group, or a sulfide group as a functional group. It is characterized by being any one or a mixture thereof.

  The resin composition according to a fourth aspect of the present invention is the resin composition according to any one of the first to third aspects, wherein the (d) inorganic hydrate is aluminum hydroxide and / or magnesium hydroxide. And

  The resin composition according to claim 5 of the present invention is characterized in that in any one of claims 1 to 4, the resin composition is crosslinked.

  According to a sixth aspect of the present invention, there is provided a resin molding comprising the resin composition according to any one of the first to fifth aspects.

  An insulated wire according to claim 7 of the present invention is characterized in that the resin composition according to any one of claims 1 to 5 is extrusion-coated on a conductor.

  The resin composition according to claim 1 of the present invention comprises a synthetic resin as a base polymer, a specific amount of a phenolic antioxidant, an imidazole antioxidant surface-treated with a silane coupling agent, and an inorganic hydrate Therefore, the resin composition has excellent flame retardancy, mechanical properties, and heat resistance, and the mechanical properties of the resin composition are such that deterioration in mechanical properties before and after the heat resistance test is also suppressed. In addition, since the component does not contain a halogen component, it is environmentally friendly and becomes a resin composition with less environmental impact when disposed by landfill or incineration.

  In the resin composition according to claim 2 of the present invention, since the synthetic resins used as the base polymer of the resin composition employ a polyolefin resin, which is a general-purpose resin, as a main component, a conventionally used polyvinyl chloride compound It is also optimal from the standpoint of replacement, and can also impart predetermined mechanical properties and the like as the base polymer of the resin composition.

  Since the resin composition which concerns on Claim 3 of this invention has selected the specific thing as a silane coupling agent which surface-treats the imidazole-type antioxidant which comprises a resin composition, the mechanical characteristic of a resin composition The heat resistance is efficiently improved, and even when the resin composition is crosslinked, the crosslinking treatment is not adversely affected.

  Since the resin composition according to claim 4 of the present invention uses magnesium hydroxide or aluminum hydroxide as a metal hydrate that is a constituent material of the resin composition, the flame retardancy of the resin composition is ensured. Can be improved.

  Since the resin composition according to claim 5 of the present invention is subjected to a crosslinking treatment, a resin composition with further improved heat resistance can be provided.

  Since the resin molded body according to claim 6 of the present invention is composed of the resin composition of the present invention, the resin molded body of the present invention enjoys the effects exhibited by the above-described resin composition of the present invention, flame retardancy, mechanical properties, heat resistance, and It becomes a resin molded body having adaptability to the environment.

  Since the insulated wire according to claim 7 of the present invention is formed by extrusion-coating the resin composition of the present invention on a conductor, the effect obtained by the resin composition of the present invention described above is enjoyed, and flame retardancy and mechanical properties are obtained. It becomes an insulated wire that combines heat resistance and adaptability to the environment.

  Hereinafter, the resin composition of the present invention will be described. The resin composition of the present invention comprises (a) 100 parts by mass of a synthetic resin, (b) 1 to 6 parts by mass of a phenol-based antioxidant, and (c) an imidazole-based oxidation surface-treated with a silane coupling agent. It contains 2 to 32 parts by mass of the inhibitor and (d) 60 to 200 parts by mass of the inorganic hydrate.

(A) Synthetic resins:
The (a) synthetic resins constituting the resin composition of the present invention serve as the base polymer of the resin composition, and make the resin composition have good mechanical properties, heat resistance and cold resistance. Examples of synthetic resins that can be used in the present invention as synthetic resins include polyethylene, polypropylene, ethylene / α-olefin copolymers, ethylene / vinyl acetate copolymers, ethylene / acrylic acid ester copolymers, ethylene・ Polymethacrylate resins such as methacrylic acid ester copolymers, ethylene / acrylic acid copolymers, ethylene / methacrylic acid copolymers, thermoplastic resins such as ionomers, polyamides, polyurethanes, polyesters, polystyrenes, thermoplastic elastomers, styrene butadiene Examples thereof include synthetic rubbers such as rubber, butadiene rubber, isoprene rubber, acrylonitrile butadiene rubber, ethylene propylene rubber, ethylene propylene terpolymer, butyl rubber, acrylic rubber, and silicone rubber. One of these synthetic resins may be used alone, or two or more of these may be used in combination.

  Specific examples of polypropylene include propylene homopolymer (H-PP), ethylene / propylene block copolymer (B-PP), and ethylene / propylene random copolymer (R-PP). Specific examples of polyethylene include very low density polyethylene (VLDPE), linear low density polyethylene (LLDPE), low density polyethylene (LDPE), medium density polyethylene (MDPE), and high density polyethylene (HDPE). Is mentioned.

  Moreover, as synthetic resin which comprises the resin composition of this invention, what was modified | denatured with the unsaturated carboxylic acid and / or its derivative about the above-mentioned synthetic resin (acid modified substance) can also be used. Examples of the unsaturated carboxylic acid include maleic acid, itaconic acid, and fumaric acid, and examples of the unsaturated carboxylic acid derivative include maleic acid monoester, maleic acid diester, maleic anhydride, itaconic acid monoester, itaconic acid diester, Examples include itaconic anhydride, fumaric acid monoester, and fumaric acid diester. Synthetic resins and these acid-modified products may be used alone or in combination of two or more.

  In the present invention, the above-described synthetic resins or synthetic resins modified with an unsaturated carboxylic acid and / or a derivative thereof are used as the base polymer of the resin composition, and conventionally used polyvinyl chloride compounds. In particular, it is preferable to use a polyolefin resin as a main component (50% by mass or more based on the entire synthetic resin) as a synthetic resin.

(B) Phenolic antioxidants:
The phenolic antioxidant (b) constituting the resin composition of the present invention is added for the purpose of imparting heat resistance to the resin composition. Examples of the phenolic antioxidant that can be used in the present invention include triethylene glycol-bis (3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate), 1,6-hexane. Diol-bis (3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate), pentaerythrityl-tetrakis (3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate ), Octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, 1,3,5-trimethyl-2,4,6-tris (3,5, -di-t-butyl) -4-hydroxybenzyl) benzene, tris (3,5-di-t-butyl-4-hydroxybenzyl) isocyanurate, isooctyl-3- (3 5-di-t-butyl-4-hydroxyphenyl) propionate and the like. Among these, 3,5-di-t-butyl-4-hydroxyphenyl is preferred because it imparts high heat resistance to the resin composition. And a group having two or more 3,5-di-t-butyl-4-hydroxybenzyl groups are preferred. One of these phenolic antioxidants may be used alone, or two or more of these may be used in combination.

  Content of the phenolic antioxidant with respect to a resin composition is 1-6 mass parts with respect to 100 mass parts of synthetic resins. By containing the phenolic antioxidant in such a range with respect to 100 parts by mass of the synthetic resin, the heat resistance of the resin composition can be reliably improved. On the other hand, when the content of the phenolic antioxidant is less than 1 part by mass, it is difficult to obtain the antioxidant effect and the heat resistance may not be improved, and the content of the phenolic antioxidant is 6 masses. When the amount exceeds 50 parts, the antioxidant is saturated with respect to the synthetic resin, and the characteristics commensurate with the content cannot be obtained. Further, depending on the type of the resin composition, there is a risk of blooming. It is preferable that content of the phenolic antioxidant with respect to a synthetic resin is 2-4 mass parts with respect to 100 mass parts of synthetic resins.

(C) Imidazole-based antioxidant surface-treated with a silane coupling agent:
The imidazole antioxidant surface-treated with the (c) silane coupling agent constituting the resin composition of the present invention can improve the heat resistance of the resin composition by adding to the resin composition, Furthermore, by being treated with a silane coupling agent, not only heat resistance but also mechanical properties can be improved.

  Examples of the imidazole antioxidant that can be used in the present invention include 2-mercaptobenzimidazole, 2-mercaptomethylbenzimidazole, a mixture of 2-mercaptobenzimidazole and a phenol condensate, and 2-mercaptobenzimidazole. Zinc salts, zinc salts of 2-mercaptomethylbenzimidazole, zinc salts of 4 and 5-mercaptomethylbenzimidazole, zinc salts of 4 and 5-mercaptomethylbenzimidazole, and the like.

  Examples of silane coupling agents include vinyl methoxy silane, vinyl triethoxy silane, 2- (3,4-epoxycyclohexyl) ethyl trimethoxy silane, 3-glycidoxy propyl trimethoxy silane, and 3-glycidoxy propyl methyl. Diethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3 -Methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, N-2- (aminoethyl) -3-aminopropylme Rutrimethoxysilane, N-2- (aminoethyl) -3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N- (1,3- Dimethyl-butylidene) propylamine, N-phenyl-3-aminopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, bis (triethoxysilylpropyl) tetrasulfide, 3-isocyanatopropyltri An ethoxysilane etc. are mentioned.

  Further, in consideration of the fact that the resin composition of the present invention may be crosslinked in order to improve mechanical properties, heat resistance, etc., among these silane coupling agents, among these silane coupling agents, a vinyl group as a functional group. It is preferable to employ one having a double bond in the structure such as methacryloxy group or acryloxy group or one having sulfur in the structure such as mercapto group or sulfide group. One of these silane coupling agents may be used alone, or a combination of two or more thereof may be used.

  The surface treatment method for imidazole antioxidants with these silane coupling agents is not particularly limited, but since the surface can be uniformly treated, a stirrer such as attritor (stirring pulverization), sand mill, bead mill, ball mill, etc. is used. Thus, it is preferable to use a method of slurrying with a silane coupling agent or a dilute solution of the silane coupling agent.

  The applied amount of the imidazole antioxidant surface-treated with the silane coupling agent is preferably 0.01 to 10 parts by mass of the silane coupling agent with respect to 1 part by mass of the imidazole antioxidant. When the application amount of the silane coupling agent is less than 0.01 parts by mass, it is difficult to improve heat resistance and mechanical properties. On the other hand, when the application amount of the silane coupling agent exceeds 10 parts by mass, improvement in properties is obtained. Even if the silane coupling agent is used, the silane coupling agent may bleed from the resin composition and may not be practically used.

  In forming a slurry, it is preferable to adjust the slurry viscosity with an additive such as a dispersant. As such a dispersant, for example, any of an anionic surfactant, a cationic surfactant, an amphoteric surfactant, a nonionic surfactant, a polymer surfactant, and the like can be used. Considering this, it is preferable to use a polymer surfactant. Examples of the polymeric surfactant include AWS-0851, Marialim AAB-0851, Marialim AFB-1521, Marialim AKM-053, Polystar OM, Polystar OMR, Polystar A-1060 (all manufactured by Nippon Oil & Fats Co., Ltd.) Is mentioned.

  Content of the imidazole antioxidant surface-treated with the silane coupling agent with respect to the resin composition is 2 to 32 parts by mass with respect to 100 parts by mass of the synthetic resins. By including the imidazole antioxidant surface-treated with the silane coupling agent in such a range with respect to 100 parts by mass of the synthetic resin, the heat resistance and mechanical properties of the resin composition can be reliably improved. . On the other hand, if the content of the imidazole antioxidant is less than 2 parts by mass, the heat resistance and mechanical properties may not be improved, and the content of the imidazole antioxidant is 32 parts by mass. When it exceeds, the characteristic according to content and cost cannot be acquired, and there exists a possibility that it may bloom depending on the kind of resin composition. It is preferable that content of the phenolic antioxidant with respect to a synthetic resin is 8-24 mass parts with respect to 100 mass parts of synthetic resins.

(D) Inorganic hydrate:
The inorganic hydrate (d) constituting the resin composition of the present invention is added for the purpose of improving the flame retardancy of the resin composition of the present invention. The inorganic hydrate that can be used in the present invention is not particularly limited and conventionally known hydrates can be used. For example, aluminum hydroxide, magnesium hydroxide, hydrated aluminum silicate, hydrated silicate Examples thereof include compounds having a hydroxyl group or crystal water such as magnesium, basic magnesium carbonate and hydrotalcite. These inorganic hydrates may be used alone or in combination of two or more.

  In the present invention, among these inorganic hydrates, it is preferable to use magnesium hydroxide or aluminum hydroxide, or to use a mixture thereof in combination, and these are used as inorganic hydrates. Thus, the flame retardancy of the resin composition of the present invention can be improved efficiently. Examples of the inorganic hydrate include magnesium hydroxide such as Kisuma (manufactured by Kyowa Chemical Co., Ltd.) and magnifin (manufactured by Albemarle).

  In addition to inorganic hydrates that have not been surface-treated, those that have been surface-treated with fatty acids, silane coupling agents, phosphate esters, and the like can be used as appropriate. By subjecting magnesium hydroxide to a surface treatment with a silane coupling agent or the like, the dispersibility of the inorganic hydrate in the resin composition can be improved. About this surface treatment, you may make it use individually a silane coupling agent, a fatty acid, and phosphate ester, or may combine these. Such surface treatment agents include alkali metal salts of higher fatty acids such as sodium caprate, sodium laurate, sodium myristate, sodium palmitate, sodium stearate, potassium stearate, sodium oleate, potassium oleate, linole. Sodium fatty acid, higher fatty acids such as capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, fatty acid amides, fatty acid esters, higher aliphatic alcohols, titanium coupling agents such as isopropyltriiso Stearoyl titanate, isopropyl tris (dioctyl borophosphate) titanate, tetraisopropyl bis (dioctyl phosphite) titanate, silane coupling agents such as vinyl tris Tokishishiran, .gamma.-methacryloxypropyltrimethoxysilane, .gamma.-glycidoxypropyltrimethoxysilane, amino coupling agent, mention may be made of silicon oil, various phosphoric acid esters and the like.

  Further, the inorganic hydrate has, for example, an average particle size in the range of 0.3 to 1.5 μm, particularly preferably an average particle size of 0 in order to improve the dispersibility in the resin composition. Those having a thickness of 0.5 to 1.0 μm and having almost no aggregation are preferable from the viewpoint of improving the mechanical properties of the resin composition.

  Content of the inorganic hydrate with respect to the resin composition of this invention is 60-200 mass parts with respect to 100 mass parts of synthetic resins. By containing the inorganic hydrate in such a range with respect to 100 parts by mass of the synthetic resin, the flame retardancy of the resin composition can be improved. On the other hand, if the content of the inorganic hydrate is less than 60 parts by mass, the flame retardancy required for a resin composition or the like used in automobiles, electrical / electronic devices, etc. cannot be obtained, and the content is 200 masses. If it exceeds the range, mechanical properties such as tensile properties are deteriorated, and the inherent flexibility of the synthetic resin is lost, and there is a problem that molding processability is deteriorated. The content of the inorganic hydrate is preferably 60 to 150 parts by mass with respect to 100 parts by mass of the synthetic resins.

  It should be noted that various resin components and rubber components other than those described above and various additives may be appropriately added to the resin composition of the present invention as necessary within the range not hindering the object and effect of the present invention. it can. Conventionally known additives can be used as additives, for example, lubricants, antioxidants other than phenolic antioxidants, light stabilizers, process oils, silicon oils, ultraviolet absorbers, carbon black, dispersants. Pigments, dyes, anti-blocking agents, cross-linking agents, cross-linking aids, metal deactivators, flame retardants, etc., and depending on applications, conventionally used red phosphorus, polyphosphoric acid compounds, hydroxystannic acid Flame retardant aids such as zinc, zinc stannate, zinc borate, calcium carbonate, hydrotalcite, and antimony oxide may be added.

  The resin composition of the present invention can be easily obtained by melt-kneading the above-described components and additives added as necessary with a conventionally known kneading apparatus such as a twin-screw kneading extruder, a Banbury mixer, a kneader, or a roller. Can be manufactured. Moreover, when a biaxial kneading extruder is used, a process can be implemented continuously.

  The kneading temperature is preferably set to be equal to or lower than the decomposition temperature of the inorganic hydrate (for example, 340 ° C. or lower when magnesium hydroxide is used as the inorganic hydrate). About other manufacturing conditions, such as extrusion amount, it can determine suitably with kinds, such as a resin component to be used.

  Moreover, you may make it bridge | crosslink the resin composition of this invention as needed. The heat resistance of the resin composition can be further improved by subjecting the resin composition to a crosslinking treatment. As a crosslinking method, a conventional electron beam irradiation crosslinking method or chemical crosslinking method can be employed. The irradiation dose of the electron beam is suitably 1 to 30 Mrad, and in order to perform crosslinking efficiently, crosslinking functionalities such as methacrylate compounds, allyl compounds, maleimide compounds, and divinyl compounds are added to the resin composition. You may add as an agent.

  In the case of the electron beam irradiation cross-linking method, the cross-linking can be performed by irradiating an electron beam by a conventional method after molding the resin composition of the present invention. On the other hand, in the case of the chemical crosslinking method, an organic peroxide or the like may be added to the resin composition as a conventionally known crosslinking agent, and after the molding, heat treatment may be performed by a conventional method for crosslinking.

  The resin composition of the present invention described above contains a synthetic resin as a base polymer, a specific amount of a phenolic antioxidant, an imidazole antioxidant surface-treated with a silane coupling agent, and an inorganic hydrate. Therefore, the resin composition has excellent flame retardancy, mechanical properties, and heat resistance, and can suppress a decrease in mechanical properties before and after the heat resistance test.

  In addition, since the resin composition of the present invention does not contain a halogen component, no toxic gas such as halogen gas or dioxin is generated during combustion, preventing the generation of toxic gas or secondary disaster in the event of a fire. The resin composition is environmentally friendly and can be disposed of without inconvenience during disposal such as incineration or landfill.

  Therefore, an insulated wire obtained by extrusion-coating a metal conductor such as a copper wire, a tin-plated copper wire, an aluminum wire, or an optical fiber (hereinafter sometimes referred to simply as “conductor”) with the resin composition of the present invention. In addition, a cable obtained by extrusion-coating the resin composition of the present invention on a cable core can be used as an insulated wire or cable having flame retardancy, heat resistance, mechanical properties, and adaptability to the environment. In particular, when an insulated wire that is extrusion-coated with the resin composition of the present invention is used as an insulated wire that is installed in an automobile or electrical / electronic device that requires heat resistance, etc., the effect is maximized. can do. These insulated wires and cables can be easily obtained by extruding and coating the outer periphery of the conductor or cable core with the resin composition of the present invention using a known extrusion molding method.

  Moreover, the resin composition of this invention can provide the resin molding which enjoys the above-mentioned outstanding effect by setting it as a resin molding. There is no restriction | limiting in particular in the shape, structure, etc. of this resin molding, For example, a power plug, a connector, a sleeve, a box, a tape base material, a tube, a sheet | seat etc. can be mentioned. These resin moldings can be easily obtained by molding the resin composition of the present invention by a conventionally known molding method such as an extrusion molding method or an injection molding method.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated more concretely, this invention is not restrict | limited at all by these Examples.

[Examples 1 to 3, Comparative Examples 1 and 2]
The structures of the resin compositions of Examples 1 to 3 and Comparative Examples 1 and 2 are shown in Table 1. The details of the materials used (synthetic resins, phenolic antioxidants, imidazole antioxidants surface treated with silane coupling agents, inorganic hydrates and additives) are as follows. Here, the content in Table 1 is shown as parts by mass when the whole synthetic resin is 100 parts by mass (for each resin material constituting the synthetic resin, the whole synthetic resin is 100% by mass. (Consent with the content (% by mass)).

(Configuration of resin composition)

(Materials used: (a) Synthetic resins)
(1) Ethylene copolymer UBE V220 (manufactured by Ube Maruzen Polyethylene Co., Ltd.)
(2) Modified polyethylene Adtex L-6100M (Nippon Polyethylene)

(Materials used: (b) phenolic antioxidants)
(3) Pentaerythrityl-tetrakis (3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate)
Irganox 1010 (Ciba Specialty Chemicals)

(Material used: (c) Imidazole type antioxidant surface-treated with silane coupling agent)
(4) For the imidazole antioxidant (silane-treated imidazole antioxidant) surface-treated with a silane coupling agent, the following silane coupling agent and imidazole antioxidant are mixed in a mass ratio. / Imidazole-based antioxidant = 6/4 mixed solution was slurried using a bead mill with the following specifications. In addition, the following polymer surfactant was used as a dispersing agent.

  In Comparative Example 1, the silane coupling agent, the imidazole antioxidant and the polymer surfactant are mixed as they are, and in Comparative Example 2, the imidazole antioxidant and the polymer surfactant are mixed as they are. used.

(Silane coupling agent)
(4-1) 3-Methacryloxypropylmethyldiethoxysilane)
KBE-502 (manufactured by Shin-Etsu Chemical Co., Ltd.)

(Imidazole type antioxidant)
(4-2) Zinc salt of 2-mercaptobenzimidazole NOCRACK MBZ (manufactured by Ouchi Shinsei Chemical Co., Ltd.)

(Dispersant)
(4-3) Polymer surfactant (polymer carboxylic acid)
Marialim AWS-0851 (manufactured by NOF Corporation)

(Bead mill specifications)
Bead mill: Vessel (capacity 0.5L)
Rotor outer diameter: 65mm
Rotor rotation speed: 2800 rpm
Bead diameter: 0.3 mm (fills 75% of the mill volume)
Vessel residence time: 12 minutes

(Material used: (d) inorganic hydrate)
(5) Aluminum hydroxide Heidilite H-42M (manufactured by Showa Denko KK)

(Material used: Additive)
(6) Metal deactivator (2 ′, 3-bis [[3- [3,5-di-tert-butyl-4-hydroxyphenyl] propionyl]] propionohydrazide)
Irganox MD1024 (Ciba Specialty Chemicals Co., Ltd.)
(7) Lubricant (calcium stearate)
Calcium stearate (Nitto Kasei Kogyo Co., Ltd.)
(8) Methacrylate crosslinking aid (trimethylolpropane trimethacrylate)
Ogmont (made by Shin-Nakamura Chemical Co., Ltd.)

  For the compositions of Examples 1 to 3 and Comparative Examples 1 and 2 shown in Table 1, the corresponding components of (1) to (8) are melt-kneaded using a known Banbury mixer to obtain a resin composition. It was a thing.

[Test Example 1]
The resin compositions obtained in Examples 1 to 3 and Comparative Examples 1 and 2 were made into sheets by the following method, and changes in tensile properties after the heat resistance test were confirmed for the samples obtained by punching the obtained sheets with dumbbells. did. Specifically, the original product (tensile test (1)), placed in an aging layer set at 180 ± 2 ° C., left for 168 hours (tensile test (2)), after left for 336 hours (tensile test (3)) “Tensile strength (tensile breaking strength) (MPa)” and “Elongation (%)” were measured under the conditions of a standard line of 20 mm and a tensile speed of 200 mm / min in accordance with JIS C3005. The results are shown in Table 2. In Table 2, () in the tensile test (2) and the tensile test (3) indicates the remaining rate (%) relative to the original product.

(Sheet manufacturing method)
Using the resin compositions obtained in Examples 1 to 3 and Comparative Examples 1 and 2, an open roll and a press were used to prepare a sheet having a thickness of 1 mm as a molded body. The prepared sheet having a thickness of 1 mm was crosslinked by electron beam irradiation under the condition of 1 MeV · 120 KGy.

(result)

  As shown in Table 2, the resin compositions of Examples 1 to 3 of the present invention did not impair the tensile strength and tensile elongation even after 180 ° C. × 336 hours (tensile test (3)), and Comparative Example 1 It turns out that it has the outstanding heat resistance with respect to 2 resin compositions. From these results, the resin composition of the present invention using an imidazole antioxidant surface-treated with a silane coupling agent becomes a resin composition in which the difference in mechanical properties after the heat resistance test is suppressed. Was confirmed.

  The resin composition of the present invention has good flame resistance, mechanical properties, heat resistance, and is environmentally friendly. For example, an insulating coating material for an insulated wire disposed in an automobile or an electric / electronic device, It can be advantageously used as a constituent material for parts and members.

Claims (7)

  (A) 1 to 6 parts by mass of a phenolic antioxidant, (c) 2 to 32 parts by mass of an imidazole antioxidant surface-treated with a silane coupling agent, with respect to 100 parts by mass of synthetic resins And (d) a resin composition comprising 60 to 200 parts by mass of an inorganic hydrate.   The resin composition according to claim 1, wherein the synthetic resin (a) contains a polyolefin resin as a main component.   The silane coupling agent is any one having a vinyl group, a methacryloxy group, an acryloxy group, a mercapto group, or a sulfide group as a functional group, or a mixture thereof. Resin composition.   The resin composition according to any one of claims 1 to 3, wherein the (d) inorganic hydrate is aluminum hydroxide and / or magnesium hydroxide.   The resin composition according to any one of claims 1 to 4, wherein the resin composition is crosslinked.   A resin molded body comprising the resin composition according to any one of claims 1 to 5. An insulated wire obtained by extrusion-coating the resin composition according to any one of claims 1 to 5 on a conductor.