Silane-modified resin composition and molded article using the same

Abstract

In a silane-modified resin composition that is lightweight, flexible, has excellent low-temperature flexibility and heat resistance, the volume resistivity is 1 × 10 without affecting the appearance or other physical properties. 15 To provide a silane-modified resin composition that can produce molded articles with high electrical insulation properties of Ω·cm or more. [Solution] A silane-modified resin composition comprising the following component (a) and the following component (b), wherein the amount of component (b) is 0.1 to 10 parts by mass per 100 parts by mass of component (a). Component (a): Olefin polymer component in which at least a portion of the olefin polymer is modified with an unsaturated silane compound, resulting in a silane-modified olefin polymer. Component (b): Magnesium hydroxide with an average major axis of 0.5–10 μm, an average thickness of 0.01–0.5 μm, and an average aspect ratio (ratio of average major axis to average thickness) of 10–100.

Description

[Technical Field]

[0001] The present invention relates to a silane-modified resin composition with excellent electrical insulation properties and a molded article using the same. [Background technology]

[0002] Silane-modified olefin resin compositions are used as coating materials for molded products and wires / cables used in construction, electrical equipment, and electronic equipment. A cable comprises a wire and an outer sheath layer covering the outer circumference of the wire. The wire has a conductor and an insulating layer covering the outer circumference of the conductor, and the outer sheath layer is provided on the outer circumference of the insulating layer.

[0003] In covering materials such as the outer sheath of the cable and the insulating layer of the electric wire, crosslinking is often performed to chemically bond the polymer molecules of the covering material in order to improve various properties, including heat resistance. Known crosslinking methods include electron beam crosslinking, chemical crosslinking, and water crosslinking.

[0004] Chemical crosslinking involves heating an olefin resin composition containing a peroxide, such as dicumyl peroxide, as a crosslinking agent to induce a crosslinking reaction. However, completing the crosslinking reaction requires a process where the molded product is heated again above the peroxide decomposition temperature to decompose the peroxide, followed by cooling. This necessitates very long and large-scale equipment. Furthermore, chemical crosslinking is difficult to control, resulting in low productivity. Electron beam crosslinking is a method of causing a crosslinking reaction in an olefin-based resin composition by irradiating it with an electron beam. Furthermore, water crosslinking involves combining a silane-modified olefin resin, which has been modified with an unsaturated silane compound such as vinyltrimethoxysilane, with a crosslinking catalyst (silanol condensation catalyst) such as an organotin compound, and crosslinking in the presence of hot water or steam. Methods using electron beam crosslinking or water crosslinking are generally used as manufacturing methods for insulated wires because, compared to chemical crosslinking, the crosslinking reaction is relatively easy to control and productivity is also good.

[0005] In recent years, due to the demand for heat resistance, materials employing this cross-linking method have been used in automotive molded parts, wires, and cables. The need for these materials is particularly high in plug-in hybrid vehicles and electric vehicles. One application of cables for plug-in hybrid vehicles and electric vehicles is charging cables, which supply electricity to the vehicles.

[0006] Not only charging cables like this one, but also various other cables such as automotive harnesses and robotic cables require the following characteristics in addition to the essential cable property of electrical insulation. (1) Lightweight design for easy handling in manual labor. (2) Flexibility to enhance design by increasing the freedom of installation space and handling within a narrow installation space. (3) Low-temperature flexibility (cold resistance) that maintains flexibility even in low-temperature environments such as winter. (4) Heat resistance to withstand high-temperature conditions when supplying large currents.

[0007] However, because automotive charging cables need to supply large amounts of current, the wires are designed to be thick and the insulation layer thick, which tends to make them stiff and heavy.

[0008] Olefin-based materials are known for their low specific gravity, high cold resistance, low flexural strength, and excellent flexibility. However, materials with excellent flexibility generally have low melting points and insufficient heat resistance. For this reason, conventionally, olefin-based materials have been crosslinked with silane to improve their heat resistance (see, for example, Patent Document 1).

[0009] Although an olefin polymer blended with magnesium hydroxide as a flame retardant and blended with calcined clay and silica (Patent Document 2) has been proposed, no sufficient effect of improving the volume resistivity has been obtained.

[0010] On the other hand, magnesium hydroxide has conventionally been known as a non-halogenated flame retardant. Patent Document 3 proposes an ethylene-based copolymer composition having flame retardancy and excellent tear strength, which is blended with magnesium hydroxide having a high aspect ratio with an average aspect ratio of 10 or more.

[0011] Patent Document 4 proposes a flame-retardant polyolefin resin composition excellent in flame retardancy, tensile properties, and molding processability, which is blended with scaly magnesium hydroxide in an ethylene-based resin component. However, in Patent Document 4, there is no description about silane modification, and also, evaluation of the volume resistivity for electrical insulation has not been performed.

Prior Art Documents

Patent Documents

[0012]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0013] According to the inventor's detailed examination of Patent Documents 1 to 4, a material that is lightweight, excellent in flexibility, low-temperature flexibility, heat resistance, does not affect the appearance and other physical properties, has a sufficiently high volume resistivity, and can impart excellent electrical insulation has not been obtained.

[0014] The present invention relates to a silane-modified resin composition that is lightweight, flexible, has excellent low-temperature flexibility and heat resistance, and has a volume resistivity of 1 × 10 without affecting appearance or other physical properties. 15 The objective is to provide a silane-modified resin composition that can produce a molded article having high electrical insulation properties of Ω·cm or more, and a molded article made from this silane-modified resin composition. [Means for solving the problem]

[0015] The inventors of the present invention have conducted extensive research to achieve the above objectives and have found that the above problems can be solved by creating a silane-modified resin composition in which magnesium hydroxide, having an average major axis of 0.5 to 10 μm, an average thickness of 0.01 to 0.5 μm, and an average aspect ratio of 10 to 100 (ratio of average major axis to average thickness), is blended with a silane-modified olefin polymer in a predetermined proportion. This has led to the completion of the present invention. In other words, the gist of this invention is as follows:

[0016] [1] A silane-modified resin composition comprising the following component (a) and the following component (b), wherein the amount of component (b) is 0.1 to 10 parts by mass per 100 parts by mass of component (a). Component (a): Olefin polymer component in which at least a portion of the olefin polymer is modified with an unsaturated silane compound, resulting in a silane-modified olefin polymer. Component (b): Magnesium hydroxide with an average major axis of 0.5–10 μm, an average thickness of 0.01–0.5 μm, and an average aspect ratio (ratio of average major axis to average thickness) of 10–100.

[0017] [2] At least a portion of the olefin polymer of component (a) has a density of 860-910 kg / m³ 3 A silane-modified resin composition according to [1], comprising an ethylene-α-olefin polymer in the range of [1].

[0018] [3] The silane-modified olefin polymer of component (a) has a density of 860-910 kg / m³ 3The silane-modified resin composition according to [2], wherein the ethylene-α-olefin polymer in the range is a silane-modified olefin polymer that has been graft-modified with an unsaturated silane compound.

[0019] [4] The silane-modified resin composition according to any one of [1] to [3], wherein component (a) comprises an olefin polymer modified with a polar group.

[0020] [5] A silane-modified resin composition according to any one of [1] to [4], further comprising a styrene-based rubber.

[0021] [6] A silane-modified resin composition according to any one of [1] to [5], further comprising an olefin-based rubber.

[0022] [7] A silane-modified resin composition according to any one of [1] to [6], further comprising one or more flame retardants selected from the group consisting of phosphorus-based flame retardants, metal hydroxide-based flame retardants with an average aspect ratio of 6 or less, and brominated flame retardants.

[0023] [8] A silane-modified resin composition according to any one of [1] to [7], further comprising a silanol condensation catalyst.

[0024] [9] A molded article obtained by crosslinking a silane-modified resin composition described in [8].

[0025]

[10] The molded article according to [9], comprising a resin composition comprising at least component (a) and a masterbatch comprising component (b) and a silanol condensation catalyst.

[0026]

[11] A molded article obtained by electron beam crosslinking a silane-modified resin composition described in any of [1] to [8]. [Effects of the Invention]

[0027] According to the silane-modified resin composition of the present invention, a silane-modified resin composition that is lightweight, flexible, has excellent low-temperature flexibility and heat resistance, and has a volume resistivity of 1 × 10 without affecting appearance or other physical properties. 15 This allows us to provide molded articles with high electrical insulation properties of Ω·cm or higher. [Modes for carrying out the invention]

[0028] The present invention will be described in detail below, but the following description is merely one example of an embodiment of the present invention, and the present invention is not limited to the following description. It can be modified and implemented as desired, within the scope of achieving the effects of the invention. In this specification, when "~" is used to enclose numerical values ​​or physical properties, it is intended to include the values ​​before and after it.

[0029] [Silane-modified resin composition] The silane-modified resin composition of the present invention comprises the following component (a) and the following component (b), wherein the amount of component (b) is 0.1 to 10 parts by mass per 100 parts by mass of component (a). Component (a): Olefin polymer component in which at least a portion of the olefin polymer is modified with an unsaturated silane compound, resulting in a silane-modified olefin polymer. Component (b): Magnesium hydroxide with an average major axis of 0.5–10 μm, an average thickness of 0.01–0.5 μm, and an average aspect ratio (ratio of average major axis to average thickness) of 10–100.

[0030] [Ingredients (a)] Component (a) in the embodiment of the present invention is an olefin polymer component in which at least a portion of the olefin polymer is modified with an unsaturated silane compound, resulting in a silane-modified olefin polymer. That is, component (a) in the embodiment of the present invention may consist only of a silane-modified olefin polymer modified with an unsaturated silane compound, or it may be a mixture of a silane-modified olefin polymer and an unmodified olefin polymer. Furthermore, component (a) according to the embodiment of the present invention may further include an olefin polymer modified with a polar group (polar group-modified olefin polymer) as described later. However, the term "polar group" as used herein does not include substituents after modification with an unsaturated silane compound. That is, component (a) in the embodiment of the present invention may contain a mixture of silane-modified olefin polymers and unmodified olefin polymers, and may also contain polar group-modified olefin polymers, insofar as the silane-modified resin composition of the present invention crosslinks with silane.

[0031] <Silane-modified olefin polymer> The silane-modified olefin polymer according to the embodiment of the present invention is obtained by graft-modifying an oleic polymer with an unsaturated silane compound. This silane-modified olefin polymer can be obtained by copolymerizing an olefin polymer with an olefinic unsaturated silane compound having a hydrolyzable organic group in the presence of a radical generator. In this reaction, the unsaturated silane compound is grafted onto the olefin polymer so as to act as crosslinking points between the base olefin polymers.

[0032] The silane-modified olefin polymer according to the embodiment of the present invention can be crosslinked with silane by contact with water in the presence of a silanol condensation catalyst or by electron beam irradiation, and a molded article with excellent heat resistance can be obtained by adopting a crosslinked structure. As described above, the silane that becomes the crosslinking component is introduced into the olefin polymer by a radical reaction of an olefinic unsaturated silane compound having a hydrolyzable organic group in the presence of a radical generator.

[0033] (Olefin polymer) The olefin polymers used in the production of silane-modified olefin polymers are not particularly limited, but include ethylene, propylene, 1-butene, 1-pentene, 2-methyl-1-butene, 3-methyl-1-butene, 1-hexene, 3-methyl-1-pentene, 4-methyl-1-pentene, 3,3-dimethyl-1-butene, 1-heptene, methyl-1-hexene, dimethyl-1-pentene, trimethyl-1-butene, ethyl-1-pentene, 1-octene, methyl-1-pentene, dimethyl-1-hexene, trimethyl-1-pentene, Examples include homopolymers of linear or branched α-olefins (including ethylene) having 2 to 20 carbon atoms, such as ethyl-1-hexene, methylethyl-1-pentene, diethyl-1-butene, propyl-1-pentene, 1-decene, methyl-1-nonene, dimethyl-1-octene, trimethyl-1-heptene, ethyl-1-octene, methylethyl-1-heptene, diethyl-1-hexene, 1-dodecene, and he-1-hexadodecene, or copolymers using any two or more of these α-olefins (including ethylene) as raw material monomers. Furthermore, these olefin polymers may also be copolymers of copolymerizable monomers other than α-olefins.

[0034] For example, propylene polymers and ethylene polymers can be used as olefin polymers.

[0035] As for propylene polymers, commercially available products can be used. Examples of commercially available polypropylene products include "Novatec® PP" manufactured by Nippon Polypropylene Co., Ltd., "Prime Polypro®" manufactured by Prime Polymer Co., Ltd., "Sumitomo Noplen®" manufactured by Sumitomo Chemical Co., Ltd., "Polypropylene Block Copolymer" manufactured by Sun Allomer Co., Ltd., and "Moplen®" manufactured by LyondellBasell.

[0036] Examples of ethylene-based polymers include low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and high-density polyethylene (HDPE). Ethylene-based copolymers such as ethylene-vinyl acetate copolymer (EVA) and ethylene-(meth)acrylic acid ester copolymer can also be used.

[0037] Commercially available ethylene polymers can also be used. Examples of commercially available polyethylenes include "Novatec® PE" from Nippon Polyethylene Co., Ltd., "LDPE" from ENEOS NUC Corporation, "Suntec®" from Asahi Kasei Corporation, "Sumikasen®" from Sumitomo Chemical Co., Ltd., and "UBE Polyethylene" from Ube Maruzen Polyethylene Co., Ltd. Examples of commercially available ethylene-vinyl acetate copolymers include "Evaflex®" from Mitsui Dow Polychemical Co., Ltd. and "Ultrasene®" from Tosoh Corporation.

[0038] As for olefin polymers, from the standpoint of flexibility, a density of 860-910 kg / m³ is desirable. 3 It is desirable to use ethylene-α-olefin copolymers within this range. If the density of the ethylene-α-olefin copolymer is above the lower limit, it will have poor flexibility, and if it is below the upper limit, it will have excellent flexibility. The density of the ethylene-α-olefin copolymer is more preferably 860 to 908 kg / m³. 3 Here, the density of the ethylene-α-olefin copolymer is the value measured by the water displacement method in accordance with JIS K-7112.

[0039] As such ethylene-α-olefin copolymers, copolymers of ethylene and linear or branched α-olefins having 3 to 10 carbon atoms are preferred. Specifically, examples of linear or branched α-olefins having 3 to 20 carbon atoms include propylene, 1-butene, 1-pentene, 1-hexene, 3-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-pentene, 4-ethyl-1-hexene, 1-octene, 3-ethyl-1-hexene, and 1-decene. These may be used individually or two or more may be copolymerized with ethylene. As for α-olefins, those having 3 to 10 carbon atoms are particularly preferred from the viewpoint of versatility and cost, and specifically, one or more of propylene, 1-butene, 1-hexene, and 1-octene are preferred.

[0040] Regarding the content of each constituent unit in the ethylene-α-olefin copolymer, it is preferable that the ratio of the content of constituent units derived from ethylene (ethylene units) to the content of constituent units derived from at least one compound selected from α-olefins having 3 to 10 carbon atoms (α-olefin units) is 95:5 to 50:50, preferably 85:15 to 60:40, as a mass ratio. In ethylene-α-olefin copolymers, although it depends on the ratio with other olefin polymers, if the ratio of ethylene units is too high, it tends to lack flexibility. Therefore, it is preferable that the ratio of α-olefin units be above the lower limit mentioned above. On the other hand, if there are too many α-olefin units, the physical properties will be inferior, so it is preferable that the ratio of α-olefin units be below the above upper limit. As long as physical properties such as moldability and tensile strength are not impaired, the ethylene-α-olefin copolymer may be a copolymer of monomer components other than ethylene and α-olefin.

[0041] Catalysts for copolymerizing ethylene and α-olefins include Ziegler-Natta catalysts and metallocene catalysts. However, ethylene-α-olefin copolymers obtained using metallocene catalysts are generally low in density and highly flexible, so it is preferable to use metallocene catalysts.

[0042] Commercially available ethylene-α-olefin copolymers can also be used. Examples of commercially available ethylene-α-olefin copolymers include "ENGAGE®" manufactured by Dow Chemical Ltd., "Tafmer®" manufactured by Mitsui Chemicals, Inc., "Adflex®" manufactured by Sun Allomer Co., Ltd. (Lyondellbasell), and "Dowlex®" manufactured by Dow.

[0043] These olefin polymers may be used individually, or two or more polymers with different copolymerization components, copolymerization ratios, and physical properties may be mixed and used together. The same applies to ethylene-α-olefin copolymers, which are suitable as olefin polymers. One type may be used alone, or two or more types with different copolymerization components, copolymerization ratios, and physical properties may be mixed and used.

[0044] (Unsaturated silane compounds) For silane modification of olefinic polymers, olefinic unsaturated silane compounds having hydrolyzable organic groups (hereinafter sometimes simply referred to as "unsaturated silane compounds") are preferably those represented by the following general formula (1). RSiR' n Y 3-n (1) (In the formula, R represents a monovalent olefinic unsaturated hydrocarbon group, Y represents a hydrolyzable organic group, R' represents a monovalent hydrocarbon group other than an aliphatic unsaturated hydrocarbon group or the same as Y, and n represents 0, 1, or 2.)

[0045] In general formula (1), R is preferably a vinyl group, allyl group, isopropenyl group, butenyl group, etc., R' is preferably a methyl group, ethyl group, propyl group, decyl group, phenyl group, etc., and Y is preferably a methoxy group, ethoxy group, formyloxy group, acetoxy group, propionoxy group, alkylamino group, arylamino group.

[0046] A more preferred unsaturated silane compound is, for example, the compound represented by the following general formula (2). CH2=CHSi(OA)3(2) (In the formula, A represents a monovalent hydrocarbon group having 1 to 8 carbon atoms.) Examples of compounds represented by the above general formula (2) include vinyltrimethoxysilane and vinyltriethoxysilane.

[0047] As an unsaturated silane compound, compounds represented by the following general formula (3) can also be preferably used. CH2=C(CH3)COOC3H6Si(OA)3(3) (In the formula, A is equivalent to the one in the general formula (2) above.) Examples of compounds represented by the above general formula (3) include γ-methacryloyloxypropyltrimethoxysilane and γ-methacryloyloxypropyltriethoxysilane.

[0048] Among these, vinyltrimethoxysilane, vinyltriethoxysilane, and γ-methacryloyloxypropyltriethoxysilane are preferred as unsaturated silane compounds. These unsaturated silane compounds may be used individually or in any combination of two or more.

[0049] The amount of unsaturated silane compound added for silane modification is typically 0.01% by mass or more, preferably 0.1% by mass or more, more preferably 0.7% by mass or more, based on the total mass of the olefin polymer, and typically 15% by mass or less, preferably 10% by mass or less, more preferably 7% by mass or less, and even more preferably 4% by mass or less. If the amount of unsaturated silane compound added is too small, sufficient grafting tends to be difficult, and if it is too large, it tends to cause poor appearance due to aggregation and the generation of discharge, as well as becoming uneconomical. Here, the amount of unsaturated silane compound added has the same meaning as the unit derived from the unsaturated silane compound in silane-modified olefin polymers.

[0050] (Radical generator) Examples of radical generators used during silane modification include various organic peroxides and peresters with strong polymerization initiation properties, such as dicumyl peroxide, α,α'-bis(t-butylperoxydiisopropyl)benzene, di-t-butyl peroxide, t-butylcumyl peroxide, di-benzoyl peroxide, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane, t-butyl peroxypivalate, di-t-butyl peroxide, and t-butylperoxy-2-ethylhexanoate. Among these, dicumyl peroxide, benzoyl peroxide, and di-t-butyl peroxide are preferred. These radical generators may be used individually or in any combination of two or more.

[0051] The amount of the radical generator added needs to be adjusted in consideration of the balance with the MFR (melt flow rate) which is an index of the fluidity of the resulting silane-modified olefin polymer and the amount of the unsaturated silane compound added. Based on the total mass of the resulting silane-modified olefin polymer, it is usually 0.01% by mass or more, preferably 0.03% by mass or more, more preferably 0.05% by mass or more, and usually 0.5% by mass or less, preferably 0.4% by mass or less, more preferably 0.2% by mass or less. If the amount of the radical generator used is too small, a sufficient grafting reaction tends not to proceed. If it is too large, the MFR of the resulting silane-modified olefin polymer decreases, the molding processability such as extrusion processability deteriorates, and the surface appearance of the resulting molded body tends to deteriorate.

[0052] The silane-modified olefin polymer contained in the component (a) may be only one kind, or may be two or more kinds having different types of the olefin polymer before modification, types of the unsaturated compound used for the modification, and the amount of the modification, etc.

[0053] <Unmodified olefin polymer> The component (a) according to the embodiment of the present invention may contain an unmodified olefin polymer that has not been silane-modified. Examples of the unmodified olefin polymer include those described above as the olefin polymer to be subjected to silane modification in the production of the silane-modified olefin polymer, and preferred ones are the same. That is, as the unmodified olefin polymer, for the same reasons as those described above in the explanation of the silane-modified olefin polymer, an ethylene·α-olefin copolymer having a density in the range of 860 to 910 kg / cm 3 is preferred. Regarding the unmodified olefin polymer such as the unmodified ethylene·α-olefin copolymer, only one kind may be included, or two or more kinds having different copolymer components, copolymerization ratios, physical properties, etc. may be included.

[0054] Furthermore, the silane-modified olefin polymer obtained by silane modification of the aforementioned olefin polymer with the aforementioned amounts of unsaturated silane compound and radical generator may also contain unmodified olefin polymers. In the embodiment of the present invention, the unmodified olefin polymer in component (a) corresponds to the sum of the unmodified olefin polymer contained in this silane-modified olefin polymer and the olefin polymer blended separately from this silane-modified olefin polymer.

[0055] <Polar group-modified olefin polymers> Component (a) in the embodiment of the present invention may contain an olefin polymer modified with a polar group. Polar group-modified olefin polymers can be obtained, for example, by modifying an unmodified olefin polymer with a compound having polar groups. Polar group-modified olefin polymers have the effect of improving the dispersibility of magnesium hydroxide, which is component (b).

[0056] (Denaturant) As compounds having polar groups used to modify olefin polymers (hereinafter also referred to as "modifiers"), unsaturated carboxylic acids, preferably α,β-unsaturated carboxylic acids, can be suitably used. Examples of α,β-unsaturated carboxylic acids include acrylic acid, methacrylic acid, ethacrylic acid, maleic acid, fumaric acid, tetrahydrophthalic acid, itaconic acid, citraconic acid, crotonic acid, and isocrotonic acid. Derivatives of these α,β-unsaturated carboxylic acids may also be used as modifiers, and examples of derivatives include acid anhydrides and esters of these α,β-unsaturated carboxylic acids. Furthermore, derivatives of acid halides, amides, imides, etc., may also be used. Among these, maleic anhydride or its derivatives are particularly preferred. That is, the modifier is preferably at least one selected from the group consisting of maleic anhydride and its derivatives.

[0057] (Olefin polymer) The olefin polymer subjected to modification with the above-mentioned modifying agent is not particularly limited, but examples include those exemplified as olefin polymers subjected to silane modification in the silane-modified olefin polymer described above.

[0058] As the olefin polymer subjected to modification with the above-mentioned modifying agent, from the viewpoint of moldability, an ethylene-based polymer or a propylene-based polymer is preferred, having a melt flow rate (MFR: measured under conditions of 190°C and 21.2N load for polymers mainly composed of ethylene, and under conditions of 230°C and 21.2N load for polymers mainly composed of propylene) in accordance with JIS K-7210:2014, preferably 0.01 to 200 g / 10 min, more preferably 0.1 to 100 g / 10 min.

[0059] The ethylene-based polymers and propylene-based polymers mentioned above can also be commercially available. Examples of commercially available ethylene-based polymers include "Novatec® PE" from Nippon Polyethylene Co., Ltd., "LDPE" from ENEOS NUC Corporation, "Suntec®" from Asahi Kasei Corporation, "Sumikasen®" from Sumitomo Chemical Co., Ltd., and "UBE Polyethylene" from Ube Maruzen Polyethylene Co., Ltd. Examples of commercially available propylene-based polymers include "Novatec® PP" from Nippon Polypropylene Co., Ltd., "Prime Polypro®" from Prime Polymer Co., Ltd., "Sumitomo Noplen®" from Sumitomo Chemical Co., Ltd., "Polypropylene Block Copolymer" from Sun Allomer Co., Ltd., and "Moplen®" from LyondellBasell.

[0060] The modification rate in polar group-modified olefin polymers is preferably 0.01 to 10% by mass, and more preferably 0.2 to 10% by mass. By setting the modification rate within the above numerical range, the inclusion of unreacted substances and by-products is suppressed, and the desired polar group-modified olefin polymer can be stably produced.

[0061] Furthermore, if the polar group-modified olefin polymer is an α,β-unsaturated carboxylic acid-modified olefin polymer, the modification rate by the α,β-unsaturated carboxylic acid is, for example, 1 This can be confirmed by methods such as H-NMR, infrared absorption spectroscopy, and ICP emission spectrometry using a high-frequency plasma emission spectrometer. For example, if the α,β-unsaturated carboxylic acid is maleic acid, the absorption characteristic of maleic acid in a sample pressed into a sheet about 100 μm thick, specifically 1900-1600 cm⁻¹, can be identified. -1 This can be determined by measuring the carbonyl characteristic absorption in the (C=O stretching vibration band). The amount of α,β-unsaturated carboxylic acid in the α,β-unsaturated carboxylic acid-modified olefin polymer measured in this manner is the sum of the amount of α,β-unsaturated carboxylic acid grafted onto the pre-modification olefin polymer, which serves as the modification substrate for the α,β-unsaturated carboxylic acid-modified olefin polymer, and the α,β-unsaturated carboxylic acid components that are not grafted onto this pre-modification olefin polymer. In this specification, the amount of α,β-unsaturated carboxylic acid, which is the sum of the α,β-unsaturated carboxylic acid grafted onto the olefin polymer modification substrate and the α,β-unsaturated carboxylic acid components that are not grafted onto the olefin polymer, measured by the above measurement method, is defined as the modification rate.

[0062] There are no particular restrictions on the modification method for producing polar group-modified olefin polymers such as α,β-unsaturated carboxylic acid-modified olefin polymers. Solution modification methods, which involve reaction in an organic solvent, and melt modification methods, which involve modification in an extruder, can be employed.

[0063] From the viewpoint of ease of controlling the modification rate, preferred α,β-unsaturated carboxylic acid-modified olefin polymers used in the present invention are maleic anhydride-modified ethylene polymers (including copolymers of ethylene and α-olefins) or maleic anhydride-modified propylene homopolymers.

[0064] As polar group-modified olefin polymers such as α,β-unsaturated carboxylic acid-modified olefin polymers, commercially available products can also be used. For example, a commercially available maleic anhydride-modified polyethylene is "Modic® 730T" manufactured by Mitsubishi Chemical Corporation.

[0065] Such polar group-modified olefin polymers may be used individually, or two or more may be mixed and used, differing in the type of α,β-unsaturated carboxylic acid used as a modifying agent, the degree of modification, and the type of olefin polymer used as the modification base.

[0066] <Content ratio> As described above, the content of the silane-modified olefin polymer in component (a) according to the embodiment of the present invention should be such that the silane-modified resin composition of the present invention is crosslinkable with silane. For example, it is preferable from the viewpoint of silane crosslinkability that component (a) contains 10 parts by mass or more, particularly 15 parts by mass or more, and especially 20 to 100 parts by mass, of the silane-modified olefin polymer produced by the aforementioned amounts of unsaturated silane compound and radical generator per 100 parts by mass of total component (a). Here, the silane-modified olefin polymer produced by the aforementioned amounts of unsaturated silane compound and radical generator may also contain an unmodified olefin polymer. Hereafter, the silane-modified olefin polymer that may contain the unmodified olefin polymer produced in this manner may be referred to as "(silane-modified) olefin polymer". Furthermore, component (a) according to the embodiment of the present invention may contain an unmodified olefin polymer. The unmodified olefin polymer, which is blended separately from the (silane-modified) olefin polymer, may contain 90 parts by mass or less, for example, 0 to 90 parts by mass, per 100 parts by mass of the total amount of component (a). Since silane-modified olefin polymers tend to generate a buildup of glue during extrusion molding, blending an unmodified olefin polymer separately from the (silane-modified) olefin polymer is effective in reducing the buildup of glue. However, if the amount of this blending is too high, the silane crosslinking properties may be impaired.

[0067] When embodiment (a) of the present invention contains a polar group-modified olefin polymer, its content is preferably 20 parts by mass or less, for example, 0 to 10 parts by mass, per 100 parts by mass of the total amount of component (a). As mentioned above, incorporating a polar group-modified olefin polymer improves the dispersibility of magnesium hydroxide in component (b). However, if the amount is too high, the physical properties tend to decrease, and blemishes may appear on the molded surface. Therefore, it is preferable to include it within the range described above.

[0068] <Ingredient (b)> Component (b) according to the embodiment of the present invention consists of magnesium hydroxide having an average major axis of 0.5 to 10 μm, an average thickness of 0.01 to 0.5 μm, and an average aspect ratio of 10 to 100, which is the ratio of the average major axis to the average thickness.

[0069] In other words, while commonly used magnesium hydroxide is in the form of particles, the magnesium hydroxide of component (b) according to the present invention is in the form of flake-shaped magnesium hydroxide that satisfies the above-mentioned specific average major axis, average thickness, and average aspect ratio.

[0070] The mechanism by which the volume resistivity increases due to the flaky magnesium hydroxide of component (b) is thought to be that component (b) takes on a dispersion form in which two crystallites form a flaky, layered structure within the resin matrix, and this layered structure functions as intercalation. In particular, magnesium hydroxide that satisfies the above-mentioned specific average major axis, average thickness, and average aspect ratio is more likely to take on this dispersion form and effectively functions to improve volume resistivity. Furthermore, magnesium hydroxide is alkaline and electrically negatively charged, and it is thought that the decrease in volume resistivity can be suppressed by incorporating cations, which are free ions such as metal ions in the olefin polymer of component (a), which is a factor in lowering volume resistivity.

[0071] The major axis of magnesium hydroxide, if it is a circular flake-shaped magnesium hydroxide in plan view, corresponds to the diameter measured by SEM observation. If the flake-shaped magnesium hydroxide has a shape other than circular in plan view, it corresponds to the distance between two parallel plates when the surface of the flake-shaped magnesium hydroxide is sandwiched between them, at the point where the distance between the plates is greatest. The average major axis is usually calculated as the average of the major axes of 100 or more flake-shaped magnesium hydroxide particles obtained by such SEM observation. Similarly, the average thickness of the flake-shaped magnesium hydroxide is calculated as the average of the thicknesses of 100 or more flake-shaped magnesium hydroxide particles measured by SEM observation. The average aspect ratio can be calculated using these ratios. However, for commercially available products, the average diameter, average thickness, and average aspect ratio can be based on catalog values. In the present invention, the average major axis, average thickness, and average aspect ratio of magnesium hydroxide refer to the average major axis, average thickness, and average aspect ratio of magnesium hydroxide used as a raw material before mixing with component (a), etc.

[0072] The average major axis of component (b) magnesium hydroxide is 0.5 μm or more, preferably 1 μm or more, more preferably 2 μm or more, and the upper limit of the average major axis is 10 μm, preferably 8 μm or less. If the average major axis is above the lower limit mentioned above, it is easier to adopt the aforementioned laminated structure dispersion form, resulting in excellent improvement in volume resistivity. If the average major axis is below the upper limit mentioned above, the impact on moldability, the physical properties of the resulting molded product, and its appearance can be minimized.

[0073] The average thickness of component (b) magnesium hydroxide is 0.01 to 0.5 μm, preferably 0.01 to 0.2 μm, and more preferably 0.01 to 0.1 μm. If the average thickness is below the above upper limit, it is easier to achieve the aforementioned laminated structure dispersion, and the effect of improving volume resistivity is excellent. Magnesium hydroxide with an average thickness below the above lower limit has inferior mechanical strength and is easily damaged during melt mixing with component (a), etc. Damage makes it difficult to achieve the aforementioned laminated structure dispersion, and it is also difficult to handle.

[0074] The average aspect ratio (average major axis / average thickness) of component (b) magnesium hydroxide is 10 to 100, preferably 20 to 90, and more preferably 30 to 90. Magnesium hydroxide with an average aspect ratio less than 10 has difficulty forming a layered dispersion structure, making it difficult to achieve an improvement in volume resistivity. Magnesium hydroxide with an average aspect ratio exceeding the above upper limit has inferior mechanical strength due to its shape, is easily damaged during melt mixing with component (a), etc., and this damage makes it difficult to form the aforementioned layered dispersion structure, and also makes it difficult to handle.

[0075] The magnesium hydroxide content of component (b) in the silane-modified resin composition of the present invention is 0.1 to 10 parts by mass, preferably 0.2 to 8 parts by mass, and more preferably 0.5 to 6 parts by mass, per 100 parts by mass of component (a). If the content of component (b) is low, the effect of improving the volume resistivity by blending component (b) with component (a) cannot be sufficiently obtained, resulting in a volume resistivity of 1 × 10⁻⁶. 15 It becomes difficult to obtain a silane-modified resin composition with high electrical insulation of Ω·cm or more. Even if component (b) is added in amounts exceeding 10 parts by mass, the effect of improving volume resistivity not only saturates, but it also tends to affect the appearance and physical properties of the resulting molded article. In other words, in the silane-modified resin composition of the present invention, the desired volume resistivity improvement effect can be obtained with a relatively small amount of magnesium hydroxide (component (b)) of 10 parts by mass or less per 100 parts by mass of component (a). Therefore, a molded article with excellent electrical insulation properties can be obtained without impairing the inherent properties of the olefin polymer component, including the (silane-modified) olefin polymer (component (a)), such as lightness, flexibility, low-temperature flexibility, and heat resistance.

[0076] The magnesium hydroxide component (b) according to the present invention may be surface-treated with, for example, one or more compounds selected from the group consisting of stearic acid, anionic surfactants, phosphate esters, silane coupling agents, titanate coupling agents, aluminum coupling agents, silicone-based treatment agents, water glass, silica, and cationic surfactants.

[0077] As component (b) of the present invention, commercially available magnesium hydroxide can be used. An example of a commercially available component (b) is "Kisma® 10A" manufactured by Kyowa Chemical Industry Co., Ltd.

[0078] In the present invention, as component (b), only one type of magnesium hydroxide may be used, provided that its average major axis, average thickness, and average aspect ratio are within the above range. Alternatively, two or more types of magnesium hydroxide with different average major axis, average thickness, and average aspect ratio are used, provided that these values ​​are within the above range. Furthermore, two or more types with or without surface treatment or with different types of surface treatment agents may be used.

[0079] Furthermore, component (b), magnesium hydroxide, can also be used as a masterbatch in the production of silane-modified resin compositions together with the silanol condensation catalyst described later.

[0080] [Silanol condensation catalyst] A silane-modified resin composition according to an embodiment of the present invention, which includes the aforementioned (silane-modified) olefin polymer, can be subjected to a crosslinking reaction in the presence of a silanol condensation catalyst, thereby converting the (silane-modified) olefin polymer into a silane-crosslinked olefin polymer, and thus forming a silane-crosslinked molded article. Therefore, the silane-modified resin composition according to the embodiment of the present invention may contain a silanol condensation catalyst.

[0081] Examples of silanol condensation catalysts include tin catalysts such as dibutyltin dilaurate, stannous acetate, dibutyltin diacetate, dibutyltin dioctoate, and dioctyltin dilaurate; lead catalysts such as lead naphthenate and lead stearate; zinc catalysts such as zinc caprylate and zinc stearate; cobalt catalysts such as cobalt naphthenate and titanium catalysts such as tetrabutyl titanate; cadmium catalysts such as cadmium stearate; and organometallic catalysts such as alkaline earth metal catalysts such as barium stearate and calcium stearate. Among these, tin catalysts are preferred from the viewpoint of crosslinking effect. These silanol condensation catalysts may be used individually or in any combination of two or more types.

[0082] When the silane-modified resin composition according to the embodiment of the present invention contains a silanol condensation catalyst, the content of the silanol condensation catalyst in the silane-modified resin composition is usually 0.01% by mass or more, preferably 0.02% by mass or more, more preferably 0.05% by mass or more, and usually 5% by mass or less, preferably 3% by mass or less, and more preferably 2% by mass or less, based on the total mass of the (silane-modified) olefin polymer in component (a). If the content of the silanol condensation catalyst is too low, the crosslinking reaction will not proceed sufficiently, and if it is too high, it will be disadvantageous in terms of cost.

[0083] In general, it is convenient to add silanol condensation catalysts as a masterbatch. A masterbatch of silanol condensation catalysts can be produced, for example, by adding the silanol condensation catalyst to one or more polyolefins such as ethylene homopolymer (polyethylene) or ethylene-α-olefin copolymer and kneading them together.

[0084] When using a silanol condensation catalyst as a masterbatch in which the silanol condensation catalyst is blended with a polyolefin, there are no particular restrictions on the content of the silanol condensation catalyst in the masterbatch, but it is generally preferable to have a content of about 0.1 to 5.0% by mass.

[0085] The silanol condensation catalyst-containing masterbatch may optionally contain other miscible thermoplastic resins, stabilizers, lubricants, fillers, colorants, foaming agents, and other additives. These additives may be any commonly used and known ones.

[0086] Commercially available products can be used as the silanol condensation catalyst-containing masterbatch. For example, Mitsubishi Chemical Corporation's "Linkron® QCM294," "LZ082," and "LZ033" can be used.

[0087] As mentioned above, in the present invention, component (b) magnesium hydroxide may be used in the production of the silane-modified resin composition of the present invention by forming a masterbatch together with a silanol condensation catalyst. By using magnesium hydroxide (b) as a masterbatch together with a silanol condensation catalyst, and then adding and mixing component (b) as a magnesium hydroxide / silanol condensation catalyst-containing masterbatch after melt-kneading component (a) and other components as needed (described later), damage to the flaky magnesium hydroxide during melt-kneading can be prevented, effectively forming the aforementioned laminated structure dispersion in the resin matrix, and potentially achieving a more effective improvement in volume resistivity. In this case, the silanol condensation catalyst content in the magnesium hydroxide / silanol condensation catalyst-containing masterbatch and the polyolefin used for masterbatching are the same as in the silanol condensation catalyst-containing masterbatch described above. The magnesium hydroxide content in the magnesium hydroxide / silanol condensation catalyst-containing masterbatch is preferably 3 to 70% by mass, and particularly preferably 10 to 60% by mass.

[0088] [Other ingredients] The silane-modified resin composition according to the embodiment of the present invention may be mixed with other polymers or rubbers other than component (a), specifically, styrene-based rubbers such as vinyl aromatic compound polymer block copolymers, olefin-based rubbers such as ethylene-α-olefin-non-conjugated diene copolymer rubbers, etc., as long as the objectives of the present invention are not impaired. Furthermore, various additives such as flame retardants, oils such as hydrocarbon-based rubber softeners, organic peroxides, etc., may also be mixed in.

[0089] <Styrene-based rubber> The silane-modified resin composition according to the embodiment of the present invention may include a vinyl aromatic compound polymer block copolymer as the styrene-based rubber.

[0090] The vinyl aromatic compound polymer block copolymer is not particularly limited as long as it has a structure comprising a vinyl aromatic compound polymer block (A1) and a conjugated diene polymer block (B1a) or a hydrogenated block (B1b) in which some or all of the carbon-carbon double bonds of the conjugated diene polymer block (B1a) are hydrogenated, and may be linear, branched, radial, etc., but it is preferable that it is a hydrogenated vinyl aromatic compound polymer block copolymer obtained by hydrogenating a block copolymer represented by the following formula (I) or (II).

[0091] A1-(B1-A1) p (I) (A1-B1) q (II) (In the formula, A1 represents a vinyl aromatic compound polymer block (A1), B1 represents a conjugated diene polymer block (B1a) or its hydrogenated block (B1b), p represents an integer from 1 to 5, and q represents an integer from 1 to 5.)

[0092] In equation (I) or (II), larger values ​​of p and q are preferable in terms of lowering the order-to-disorder transition temperature of the rubbery polymer, but smaller values ​​are preferable in terms of ease of manufacture and cost.

[0093] As for the hydrogenated block copolymer of vinyl aromatic compound polymer block copolymers, the hydrogenated block copolymer represented by formula (I) is preferred over the hydrogenated block copolymer represented by formula (II) because of its excellent rubber elasticity, the hydrogenated block copolymer represented by formula (I) with p of 3 or less is more preferred, the hydrogenated block copolymer represented by formula (I) with p of 2 or less is even more preferred, and the hydrogenated block copolymer represented by formula (I) with p of 1 is the most preferred.

[0094] From the viewpoint of compatibility with component (a) and furthermore, the inclusion of hydrocarbon-based rubber softeners described later, it is preferable that the vinyl aromatic compound polymer block copolymer is at least one selected from the group consisting of (A1)-(B1) block copolymers and (A1)-(B1)-(A1) block copolymers, which consist of a vinyl aromatic compound polymer block (A1) and a conjugated diene polymer block (B1a) or a hydrogenated block (B1b) in which some or all of the carbon-carbon double bonds of the conjugated diene polymer block (B1a) are hydrogenated.

[0095] Examples of vinyl aromatic compounds constituting the vinyl aromatic compound polymer block (A1) include one or more of styrene, t-butylstyrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 1,3-dimethylstyrene, vinylnaphthalene, and vinylanthracene, with styrene and α-methylstyrene being particularly preferred, and styrene being the most preferred.

[0096] The content of vinyl aromatic compound polymer block (A1) relative to 100% by mass of total polymer block in the vinyl aromatic compound polymer block copolymer is preferably 10% by mass or more, more preferably 15% by mass or more, and even more preferably 20% by mass or more, from the viewpoint of mechanical properties such as tensile strength and heat resistance. The content of vinyl aromatic compound polymer block (A1) is preferably 50% by mass or less, more preferably 45% by mass or less, and even more preferably 40% by mass or less, from the viewpoint of flexibility and rubber elasticity, and from the viewpoint of bleeding suppression when used in combination with the hydrocarbon-based rubber softener described later. For example, the ratio of the vinyl aromatic compound polymer block (A1) to 100% by mass of the total polymer block contained in the vinyl aromatic compound polymer block copolymer can be 10 to 50% by mass.

[0097] The vinyl aromatic compound polymer block copolymer may contain hydrogenated blocks (B1b) with a hydrogenation rate of preferably 80% or more, more preferably 85% or more, and even more preferably 90% or more. The inclusion of such hydrogenated blocks (B1b) in the vinyl aromatic compound polymer block copolymer is preferable because it improves durability against heat and weathering.

[0098] Examples of conjugated diene polymer blocks (B1a) or hydrogenated blocks (B1b) of vinyl aromatic compound polymer block copolymers include, for example, a conjugated diene polymer block derived from at least one selected from the group of conjugated diene monomers consisting of butadiene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, 4,5-diethyl-1,3-octadiene, and 3-butyl-1,3-octadiene; a conjugated diene polymer block derived from a combination of isoprene and at least one selected from the group of conjugated diene monomers; or a hydrogenated block in which some or all of the carbon-carbon double bonds of the conjugated diene polymer block are hydrogenated. Of these, those derived solely from butadiene, or from butadiene and isopropylene, with a mass ratio of butadiene / isoprene = 2 / 8 to 6 / 4, are particularly preferred.

[0099] The lower limit of the mass-average molecular weight of the vinyl aromatic compound polymer block copolymer, measured by gel permission chromatography in terms of polystyrene, is preferably 80,000 or higher, from the viewpoint of rubber elasticity, mechanical strength, and, when used in combination with the hydrocarbon-based rubber softener described later, bleed suppression. The upper limit of the mass-average molecular weight of the vinyl aromatic compound polymer block copolymer is preferably 1,000,000 or less, more preferably 600,000 or less, and even more preferably 400,000 or less, from the viewpoint of fluidity. For example, the mass-average molecular weight of a vinyl aromatic compound polymer block copolymer rubber measured by the above method can be between 80,000 and 1,000,000.

[0100] The method for producing vinyl aromatic compound polymer block copolymers can be any method as long as the above structure and physical properties are obtained. For example, the method described in Japanese Patent Publication No. 40-23798, or the method of carrying out block polymerization in an inert solvent in the presence of a lithium catalyst, can be employed. Furthermore, the hydrogenation treatment of these block copolymers can be carried out in an inert solvent in the presence of a hydrogenation catalyst by methods described in, for example, Japanese Patent Publication No. 42-8704, Japanese Patent Publication No. 43-6636, Japanese Unexamined Patent Publication No. 59-133203, Japanese Unexamined Patent Publication No. 60-79005, etc.

[0101] Furthermore, the hydrogenated block copolymer of the vinyl aromatic compound polymer block copolymer may be a block copolymer in which the polymer molecular chain is extended or branched via coupling agent residues. Examples of coupling agents used in this case include diethyl adipate, divinylbenzene, tetrachlorosilicon, butyltrichlorosilicon, tetrachlorotin, butyltrichlorotin, 1,2-dibromoethane, 1,4-chloromethylbenzene, 1,2-bis(trichlorosilyl)ethane, epoxidized linseed oil, tolylene diisocyanate, and 1,2,4-benzenetriisocyanate.

[0102] Examples of commercially available vinyl aromatic compound polymer block copolymers include "TAIPOL®" manufactured by TSRC, "KRATON®-G" manufactured by Kraton Polymers, "Septon®" manufactured by Kuraray Co., Ltd., and "ToughTec®" manufactured by Asahi Kasei Chemicals Corporation.

[0103] A single vinyl aromatic compound polymer block copolymer may be used, or two or more types with different block compositions and physical properties may be mixed and used.

[0104] If the silane-modified resin composition according to the embodiment of the present invention contains a styrene-based rubber such as a vinyl aromatic compound polymer block copolymer, the content of the rubber is preferably 40 parts by mass or less, for example, 5 to 30 parts by mass, per 100 parts by mass of component (a). While the inclusion of styrene-based rubber can improve flexibility and other properties, too little content will not provide sufficient benefits, while too much will reduce heat resistance and tensile strength.

[0105] <Hydroxide-based rubber softener> The silane-modified resin composition according to the embodiment of the present invention may contain a hydrocarbon-based rubber softener. In particular, if the above-mentioned styrene-based rubber is included, it is preferable to include a hydrocarbon-based rubber softener.

[0106] For rubber blistering agents, hydrocarbons with a mass-average molecular weight of typically 300 to 2,000, preferably 500 to 1,500, are used, and mineral oil-based hydrocarbons or synthetic resin-based hydrocarbons are preferred. Here, the mass-average molecular weight is the molecular weight on a polystyrene basis, measured by gel permission chromatography.

[0107] Generally, hydrocarbon-based rubber softeners are mixtures of aromatic hydrocarbons, naphthenic hydrocarbons, and paraffinic hydrocarbons. Aromatic oils are those in which the proportion of carbon atoms of aromatic hydrocarbons is 35% by mass or more of the total carbon content, naphthenic oils are those in which the proportion of carbon atoms of naphthenic hydrocarbons is 30-45% by mass, and paraffinic oils are those in which the proportion of carbon atoms of paraffinic hydrocarbons is 50% by mass or more. In the embodiments of the present invention, paraffinic oils are preferably used, and paraffinic oils with a mass-average molecular weight of 300-2,000 are more preferably used. The suitable kinematic viscosity, pour point, and flash point of the paraffin-based oil are the same as those for the oil-expanded ethylene-α-olefin-non-conjugated diene copolymer rubber described later.

[0108] A single hydrocarbon-based rubber softener may be used, or two or more may be used in mixture form.

[0109] If the silane-modified resin composition according to the embodiment of the present invention contains a hydrocarbon-based rubber softener, the amount thereof is preferably 200 parts by mass or less, for example, 20 to 180 parts by mass, per 100 parts by mass of the styrene-based rubber. By including a hydrocarbon-based rubber softener, it is possible to increase flexibility, lower the viscosity of styrene-based rubber, and improve moldability. However, if the amount is too low, these effects cannot be fully obtained, and if it is too high, bleeding of the hydrocarbon-based rubber softener may occur. In this context, the content of the hydrocarbon-based rubber softener refers to the total amount of the hydrocarbon-based rubber softener, including the amount in the oil-expanded ethylene-α-olefin-non-conjugated diene copolymer rubber described later, when the silane-modified resin composition according to the embodiment of the present invention contains the oil-expanded ethylene-α-olefin-non-conjugated diene copolymer rubber.

[0110] <Olefin-based rubber> The silane-modified resin composition according to the embodiment of the present invention may contain olefin-based rubber (excluding those corresponding to component (a)).

[0111] As an olefin-based rubber, ethylene-α-olefin-non-conjugated diene copolymer rubber can be used from the viewpoint of improving moldability and flexibility. Ethylene-α-olefin-non-conjugated diene copolymer rubber is a copolymer containing ethylene, α-olefin, and a non-conjugated diene compound as copolymer components.

[0112] Ethylene-α-olefin-non-conjugated diene copolymer rubber includes an oil-expanding type, which is a mixture of ethylene-α-olefin-non-conjugated diene copolymer rubber and a hydrocarbon-based rubber softener (hereinafter sometimes referred to as "oil-expanding ethylene-α-olefin-non-conjugated diene copolymer rubber"), and a non-oil-expanding type, which does not contain a hydrocarbon-based rubber softener. In this embodiment, the oil-expanding type copolymer rubber is intended, but low-oil-expanding types or non-oil-expanding types can also be suitably used. That is, in the present invention, ethylene-α-olefin-non-conjugated diene copolymer rubber can be used in either oil-expanding or non-oil-expanding types. Only one type of oil-expanding or non-oil-expanding type may be used alone, or two or more types may be used in any combination and ratio. One or more oil-expanding types and one or more non-oil-expanding types may also be used in any combination and ratio.

[0113] Examples of α-olefins constituting the ethylene-α-olefin-non-conjugated diene copolymer rubber include propylene, 1-butene, 3-methyl-1-butene, 1-pentene, 4-methyl-1-pentene, 4,4-dimethyl-1-pentene, 1-hexene, 4-methyl-1-hexene, 1-heptene, 1-octene, 1-decene, and 1-octadecene, which have 3 to 20 carbon atoms, more preferably 3 to 8 carbon atoms, but are not particularly limited to these. Among these, propylene, 1-butene, 3-methyl-1-butene, and 1-pentene are preferred from the viewpoint of crosslinking properties by the crosslinking agent during dynamic crosslinking and suppression of bloom-out, and propylene and 1-butene are more preferred. Note that α-olefins can be used individually or in any combination and ratio of two or more types.

[0114] Examples of non-conjugated diene compounds include dicyclopentadiene, 1,4-hexadiene, cyclohexadiene, cyclooctadiene, dicyclooctadiene, 1,6-octadiene, 5-methyl-1,4-hexadiene, 3,7-dimethyl-1,6-octadiene, 1,3-cyclopentadiene, 1,4-cyclohexadiene, 2-methyl-1,5-hexadiene, 6-methyl-1,5-heptadiene, Examples of suitable compounds include 7-methyl-1,6-octadiene, tetrahydroindene, methyltetrahydroindene, 5-isopropylidene-2-norbornene, 5-vinyl-2-norbornene, vinylidene norbornene, ethylidene norbornene such as 5-ethylidene-2-norbornene (ENB), and methylene norbornene such as 5-methylene-2-norbornene (MNB), but the compound is not particularly limited to these. Among these, dicyclopentadiene, ethylidene norbornene, and vinylidene norbornene are preferred from the viewpoint of crosslinking properties by the crosslinking agent during dynamic crosslinking, and more preferably dicyclopentadiene, 5-ethylidene-2-norbornene, and vinylidene norbornene. The non-conjugated diene compound can be used alone or in any combination and ratio of two or more types.

[0115] Specific examples of ethylene-α-olefin-non-conjugated diene copolymer rubber include ethylene-propylene-5-ethylidene-2-norbornene copolymer rubber, ethylene-propylene-dicyclopentadiene copolymer rubber, ethylene-propylene-1,4-hexadiene copolymer rubber, ethylene-propylene-5-vinyl-2-norbornene copolymer rubber, and other ethylene-propylene-non-conjugated diene copolymer rubbers (EPDM), as well as ethylene-1-butene-5-ethylidene-2-norbornene copolymer rubber, but are not particularly limited to these. Among these, ethylene-propylene-non-conjugated diene copolymer rubber (EPDM) is preferred from the viewpoint of crosslinking properties by the crosslinking agent during dynamic crosslinking and suppression of bloom-out. Note that ethylene-α-olefin-non-conjugated diene copolymer rubber can be used alone or in any combination and ratio of two or more types.

[0116] The ethylene unit content in the ethylene-α-olefin-non-conjugated diene copolymer rubber is not particularly limited, but is preferably 50 to 90% by mass, more preferably 55 to 85% by mass, and even more preferably 60 to 80% by mass. When the ethylene unit content is within the above preferred range, it is easier to obtain a silane-modified resin composition with excellent mechanical strength and rubber elasticity.

[0117] Furthermore, the content of α-olefin units in the ethylene-α-olefin-non-conjugated diene copolymer rubber is not particularly limited, but is preferably 10 to 50% by mass, more preferably 15 to 45% by mass, and even more preferably 20 to 40% by mass. When the content of α-olefin units is within the above preferred range, it is easier to obtain a silane-modified resin composition that is excellent in mechanical strength, moderate flexibility, and rubber elasticity.

[0118] Furthermore, the content of non-conjugated diene units in the ethylene-α-olefin-non-conjugated diene copolymer rubber is not particularly limited, but is preferably 0.5 to 30% by mass, more preferably 1 to 20% by mass, and even more preferably 2 to 10% by mass. When the content of non-conjugated diene units is within the above preferred range, it becomes easier to adjust the crosslinkability and moldability, and a silane-modified resin composition with excellent mechanical strength and rubber elasticity tends to be obtained.

[0119] The content of each constituent unit of ethylene-α-olefin-non-conjugated diene copolymer rubber can be determined by infrared spectroscopy.

[0120] As for ethylene-α-olefin-non-conjugated diene copolymer rubber, ethylene-propylene-non-conjugated diene copolymer rubber rubber copolymers are particularly preferred, having an ethylene unit content of 55 to 75% by mass, a propylene unit content of 15 to 40% by mass, and a content of at least one non-conjugated diene unit selected from the group consisting of dicyclopentadiene, 5-ethylidene-2-norbornene, and vinylidene norbornene of 1 to 10% by mass.

[0121] As a method for producing ethylene-propylene-non-conjugated diene copolymer rubber (EPDM), known polymerization methods using known olefin polymerization catalysts can be applied. For example, EPDM can be produced by slurry polymerization, solution polymerization, bulk polymerization, gas-phase polymerization, etc., using complex catalysts such as Ziegler-Natta catalysts, metallocene complexes, and non-metallocene complexes. Here, Ziegler-Natta catalysts are polymerization catalysts consisting of titanium compounds or vanadium compounds and organoaluminum compounds, while metallocene complex catalysts are highly active polymerization catalysts consisting of cyclopentadienyl derivatives of transition metals such as titanium and zirconium and co-catalysts. Generally, solution polymerization using aliphatic hydrocarbons as solvents is mainly employed, and in some cases, slurry polymerization using monomers as the main solvent is also employed. In addition, gas-phase polymerization, in which the polymerization reaction is carried out in monomer gas using various inert materials (e.g., carbon black) as dispersants, has also been industrialized. Unlike gas-phase polymerization, synthesis by solution polymerization does not contain carbon black or the like in the polymer, so it is excellent at suppressing bloom-out. Furthermore, using metallocene-based complex catalysts yields even better results in suppressing bloom-out. On the other hand, synthesis by gas-phase polymerization can produce polymers with higher molecular weight than by solution polymerization or slurry polymerization, resulting in higher Mooney viscosity, which is effective in improving oil resistance and compression set.

[0122] The mass-average molecular weight of ethylene-α-olefin-non-conjugated diene copolymer rubber, calculated as polypropylene by gel permeation chromatography (GPC), is not particularly limited, but is preferably 100,000 or more, more preferably 200,000 or more, even more preferably 300,000 or more, preferably 1,000,000 or less, more preferably 900,000 or less, and even more preferably 800,000 or less. When the mass-average molecular weight of ethylene-α-olefin-non-conjugated diene copolymer rubber is within the above preferred range, moldability and processability are improved, and the bleed-out of hydrocarbon-based rubber softeners tends to be suppressed.

[0123] In this specification, the measurement conditions for the mass-average molecular weight of ethylene-α-olefin-non-conjugated diene copolymer rubber in terms of polypropylene, based on the GPC method, are as follows. Equipment :Waters 150C Column: Shodex AD806MS x 3 (8.0mm inner diameter x 300mm length) Detector: IR (dispersive, 3.42 μm) Solvent: ODCB (o-dichlorobenzene) Temperature: 140℃ Flow rate: 1.0mL / min Injection volume: 200μL Concentration: 10mg / mL Calibration sample: Polydispersible standard polyethylene Calibration method: Using the Mark-Houwink formula to convert to polypropylene

[0124] The density of ethylene-α-olefin-non-conjugated diene copolymer rubber is not particularly limited, but is approximately 0.850 g / cm³. 3 Preferably, it is 0.860 g / cm³ or more, and more preferably 0.860 g / cm³. 3 That is all, on the other hand, 0.900 g / cm³ 3 Preferably, it is less than or equal to 0.890 g / cm³. 3 The following applies: When the density of the ethylene-α-olefin-non-conjugated diene copolymer rubber is within the above preferred range, it tends to be easier to obtain a silane-modified resin composition with excellent processability, moldability, flexibility, etc. This density can be measured according to JIS K-7112:1999.

[0125] Mooney viscosity (ML) of non-oil-spread ethylene-α-olefin-non-conjugated diene copolymer rubber (pre-oil-spread ethylene-α-olefin-non-conjugated diene copolymer rubber) 1+4 The Mooney viscosity (ML) of the oil-expanded ethylene-α-olefin-conjugated diene copolymer rubber is not particularly limited, but is preferably 15 to 400, more preferably 30 to 300. 1+4The temperature (up to 125°C) is not particularly limited, but is preferably 15 to 100, more preferably 30 to 80. The Mooney viscosity of the α-olefin-non-conjugated diene copolymer rubber is preferably above the lower limit from the viewpoint of improving the appearance of the resulting molded article, and preferably below the upper limit from the viewpoint of moldability and low-temperature impact resistance.

[0126] Mooney viscosity (ML) of ethylene-α-olefin-non-conjugated diene copolymer rubber before oil spreading. 1+4 Mooney viscosity (ML) of oil-expanded ethylene-α-olefin-non-conjugated diene copolymer rubber (at 125℃). 1+4 The relationship between the temperature (125°C) and the Mooney viscosity (ML) of the oil-spread ethylene-α-olefin-non-conjugated diene copolymer rubber is expressed by the following formula, as described in Japanese Patent Publication No. 1-103639. 1+4 (At 125°C) ML2 can be calculated by measuring the Mooney viscosity ML1 of the ethylene-α-olefin-non-conjugated diene copolymer rubber before oil application, using the following formula. Calculation formula: log(ML1 / ML2)=0.0066(ΔPHR) ML1: Mooney viscosity of oil-spread ethylene-α-olefin-non-conjugated diene copolymer rubber before oil spreading. ML2: Mooney viscosity of oil-spread ethylene-α-olefin-non-conjugated diene copolymer rubber ΔPHR: Oil spread per 100 parts by mass of ethylene-α-olefin-non-conjugated diene copolymer rubber

[0127] In oil-spread ethylene-α-olefin-conjugated diene copolymers, hydrocarbon-based rubber softeners are used to soften the ethylene-α-olefin-non-conjugated diene copolymer rubber, increasing its flexibility and elasticity, and to improve the processability and fluidity of the resulting silane-modified resin composition.

[0128] Examples of hydrocarbon-based rubber softeners used in oil-expanded ethylene-α-olefin-conjugated diene copolymer rubber include mineral oil-based rubber softeners and synthetic resin-based rubber softeners. Among these, mineral oil-based rubber softeners are preferred from the viewpoint of affinity with other components. As mentioned above, hydrocarbon-based rubber softeners are mixtures of aromatic hydrocarbons, naphthenic hydrocarbons, and paraffinic hydrocarbons, and the details of paraffinic oils, naphthenic oils, and aromatic oils are as described above. Among these, paraffinic rubber softeners (paraffinic oils) are preferred as hydrocarbon-based rubber softeners for oil-expanded ethylene-α-olefin-conjugated diene copolymer rubber. Furthermore, a single type of hydrocarbon-based rubber softener may be used alone, or two or more types may be used in any combination and ratio.

[0129] The paraffin-based oil used in oil-expanded ethylene-α-olefin-non-conjugated diene copolymer rubber is not particularly limited, but it is preferable to use one with a kinematic viscosity at 40°C of 20 cSt (centistokes) or higher, preferably 50 cSt or higher, and usually 800 cSt or lower, preferably 600 cSt or lower. Furthermore, the pour point is usually -40°C or higher, preferably -30°C or higher, and preferably 0°C or lower. In addition, the flash point (COC) is usually 200°C or higher, preferably 250°C or higher, and usually 400°C or lower, preferably 350°C or lower.

[0130] When using oil-expanded ethylene-α-olefin-non-conjugated diene copolymer rubber, the content ratio of ethylene-α-olefin-non-conjugated diene copolymer rubber to hydrocarbon-based rubber softener is not particularly limited, but the content of hydrocarbon-based rubber softener is usually 10 parts by mass or more, preferably 20 parts by mass or more, per 100 parts by mass of ethylene-α-olefin-non-conjugated diene copolymer rubber, while it is usually 200 parts by mass or less, preferably 160 parts by mass or less, and more preferably 120 parts by mass or less.

[0131] The method for preparing oil-expanded ethylene-α-olefin-non-conjugated diene copolymer rubber (oil-expanding method) is not particularly limited, and known methods can be used. Examples of oil-expanding methods include a method in which ethylene-α-olefin-non-conjugated diene copolymer rubber and a hydrocarbon-based rubber softener are mechanically kneaded together using a mixing roll or Banbury mixer and then oil-expanded; a method in which a predetermined amount of hydrocarbon-based rubber softener is added to ethylene-α-olefin-non-conjugated diene copolymer rubber and then the solvent is removed by methods such as steam stripping; and a method in which a mixture of crumb-like ethylene-α-olefin-non-conjugated diene copolymer rubber and a hydrocarbon-based rubber softener is stirred and impregnated using a Henschel mixer or the like. From the viewpoint of preparing high molecular weight oil-expanded ethylene-α-olefin-non-conjugated diene copolymer rubber, a method in which a predetermined amount of hydrocarbon-based rubber softener is added to a polymerization reaction solution or suspension of ethylene-α-olefin-non-conjugated diene copolymer rubber and then the solvent is removed is preferred.

[0132] Furthermore, ethylene-α-olefin-non-conjugated diene copolymer rubbers of various grades are commercially available from domestic and international manufacturers, and these commercially available products can be used. Examples of commercially available products include "JSR EPR" from JSR Corporation, "Mitsui EPT" from Mitsui Chemicals, Inc., "Esplen®" from Sumitomo Chemical Co., Ltd., and "Keltan®" from ARLANXEO.

[0133] If the silane-modified resin composition according to the embodiment of the present invention contains these ethylene-α-olefin-non-conjugated diene copolymer rubbers, the content thereof is preferably 20 parts by mass or less, for example, 0 to 10 parts by mass, per 100 parts by mass of component (a). While the inclusion of ethylene-α-olefin-non-conjugated diene copolymer rubber can improve flexibility and moldability, if the content is too low, these effects cannot be fully achieved, and if it is too high, it is prone to degradation when in contact with metals such as conductors.

[0134] <Flame retardant> The silane-modified resin composition according to the embodiment of the present invention may contain, as a flame retardant, magnesium hydroxide with an aspect ratio of less than 10, metal hydroxides such as aluminum hydroxide, phosphorus-based flame retardants, melamine cyanurate compounds, zinc borate, halogen-based flame retardants such as brominated flame retardants, and antimony-based flame retardants such as antimony trioxide.

[0135] Of these, it is preferable to include one or more selected from the group consisting of phosphorus-based flame retardants, metal hydroxide-based flame retardants with an average aspect ratio of 6 or less, and bromine-based flame retardants, as this can impart flame retardancy.

[0136] If the silane-modified resin composition according to the embodiment of the present invention contains these flame retardants, it is preferable that the amount is 70 parts by mass or less, for example, 10 to 70 parts by mass, per 100 parts by mass of component (a). If the amount of flame retardant is above the lower limit mentioned above, the flame retardant effect can be effectively obtained. However, if the amount is too high, the moldability and physical properties will deteriorate.

[0137] <Organic peroxide> A silane-modified resin composition according to an embodiment of the present invention, containing components (a) and (b) as essential components, can be produced by heating and mixing components (a) and (b) together with other polymer components and rubber components as needed using a mixer such as an extruder. In this process, organic peroxides and crosslinking aids may be mixed in to perform a crosslinking treatment.

[0138] Examples of organic peroxides include dimethyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-di-(t-butylperoxy)hexane, 2,5-dimethyl-2,5-di-(t-butylperoxy)hexyn-3, 1,3-bis(t-butylperoxyisopropyl)benzene, 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane, n-butyl-4,4-bis(t-butylperoxy)valerate, benzoyl peroxide, p-chlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, t Examples include butylperoxybenzoate, t-butylperoxyisopropyl carbonate, diacetyl peroxide, lauroyl peroxide, and t-butylcumyl peroxide, preferably 2,5-dimethyl-2,5-di-(t-butylperoxy)hexane, 2,5-dimethyl-2,5-di-(t-butylperoxy)hexyn-3, 1,3-bis(t-butylperoxyisopropyl)benzene, 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane, and n-butyl-4,4,-bis(t-butylperoxy)valerate. These organic peroxides can be used individually or in combination of two or more.

[0139] The organic peroxide is typically used in the range of 0.01 to 3 parts by mass, preferably 0.02 to 2 parts by mass, based on 100 parts by mass of the total of component (a) and other polymer components and rubber components that are optionally blended.

[0140] In these crosslinking treatments using organic peroxides, peroxycrosslinking aids such as sulfur, p-quinone dioxime, p,p'-dibenzoylquinone dioxime, N-methyl-N-4-dinitrosoaniline, nitrosobenzene, diphenylguanidine, and trimethylolpropane-N,N'-m-phenylenedimaleimide, polyfunctional methacrylate monomers such as divinylbenzene, triallyl cyanurate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, and allyl methacrylate, and polyfunctional vinyl monomers such as vinyl butyrate and vinyl acetate can be incorporated as crosslinking aids.

[0141] The above-mentioned crosslinking aid is typically used in an amount of 0.1 to 5 parts by mass, preferably 0.2 to 4 parts by mass, relative to 100 parts by mass of the total amount of component (a) and other polymer components and rubber components that may be blended as needed.

[0142] <Other additives> The silane-modified resin composition according to the embodiment of the present invention may optionally contain various additives such as metal deactivators, stabilizers, lubricants, antioxidants, ultraviolet absorbers, foaming agents, colorants, and fillers, as long as they do not impair the objectives of the present invention.

[0143] As a metal deactivator, N,N'-bis(3-(3,5-di-t-butyl-4-hydro Xyphenyl)propionyl)hydrazine, 3-(N-salicyloyl)amino-1,2, 4-Triazole, and 2,2'-Oxamide bis-(ethyl 3-(3,5-di-t- Examples include butyl-4-hydroxyphenyl (propionate) and others.

[0144] As a stabilizer, it is preferable to include an antioxidant. Examples of antioxidants include monophenols, bisphenols, tri-polyphenols or more, thiobisphenols, naphthylamines, diphenylamines, and phenylenediamines. Among these, monophenols, bisphenols, tri-polyphenols or more, and thiobisphenol antioxidants are preferred. When an antioxidant is added, the amount added is usually 0.01 to 8 parts by mass, preferably 0.05 to 5 parts by mass, per 100 parts by mass of the total of component (a) and other polymer components and rubber components as needed. If the amount added is less than 0.01 parts by mass, the antioxidant effect is difficult to obtain, and if it exceeds 8 parts by mass, the improvement effect commensurate with the amount added is not obtained, which is undesirable from a cost perspective.

[0145] Examples of fillers include glass fibers, hollow glass spheres, carbon fibers, talc, calcium carbonate, mica, potassium titanate fibers, silica, metal soaps, titanium dioxide, and carbon black. These can be used individually or in any combination and ratio of two or more types.

[0146] [Method for producing silane-modified resin compositions] The silane-modified resin composition according to the embodiment of the present invention can be produced by mixing, kneading, or melt-kneading a blend of materials containing at least component (a) and component (b), and optionally other polymer components, rubber components, organic peroxides, crosslinking aids, and various additives, in accordance with conventional methods using a conventional extruder, Banbury mixer, pressure kneader mixing roll, roll, brabender plastograph, kneader brabender, etc.

[0147] When producing a silane-modified resin composition according to an embodiment of the present invention by melt-kneading, it is preferable to perform a dynamic heat treatment in which the mixture is melt-kneaded while heated to a temperature of 80 to 300°C, preferably 100 to 250°C. The processing time for the dynamic heat treatment is not particularly limited, but considering productivity and other factors, it is usually 0.1 to 30 minutes.

[0148] [Molding of silane-modified resin compositions] The silane-modified resin composition according to the embodiment of the present invention can be molded using molding machines such as injection molding machines, single-screw extruders, twin-screw extruders, compression molding machines, and calendering machines. Of these, extrusion molding is preferred because it is suitable for components such as cables and electric wires.

[0149] [Water bridge] In the silane-modified resin composition according to the embodiment of the present invention, the above-mentioned silanol condensation catalyst is incorporated, and after molding by various molding methods such as extrusion molding, injection molding, and press molding, the crosslinking reaction between silanol groups is promoted by exposure to an aqueous atmosphere to obtain a molded article made of the crosslinked silane-modified resin composition. In this case, the silanol condensation catalyst can be incorporated as a silanol condensation catalyst-containing masterbatch, as described above. Furthermore, component (b) can also be incorporated as a magnesium hydroxide / silanol condensation catalyst-containing masterbatch. Various methods can be used to expose the product to a watery atmosphere, including leaving it in air containing moisture, blowing in air containing water vapor, immersing it in a water bath, and spraying warm water in a mist.

[0150] The rate of the crosslinking reaction depends on the conditions under which the material is exposed to a water atmosphere, but typically, exposure within a temperature range of 20-130°C and for 10 minutes to 2 weeks is sufficient. Particularly preferred conditions are a temperature range of 60-110°C and exposure for 30 minutes to 24 hours. When using air containing moisture, the relative humidity should be selected from a range of 1-100%.

[0151] The degree of crosslinking of the silane-modified resin composition obtained in this way can be adjusted by changing the type and amount of silanol condensation catalyst, the conditions for crosslinking (temperature, time), etc.

[0152] [Electron beam crosslinking] The silane-modified resin composition according to the embodiment of the present invention can also be formed into a crosslinked molded article by electron beam crosslinking. In this case, the silane-modified resin composition according to the embodiment of the present invention does not necessarily need to contain a silanol condensation catalyst. By irradiating a molded article obtained by molding a silane-modified resin composition without a silanol condensation catalyst using the method described above with an electron beam, a crosslinked molded article with excellent heat resistance, mechanical properties, etc., can be obtained. In this case, for example, electron beam irradiation is performed such that the irradiation intensity is preferably 60 kGy or more, more preferably 80 kGy or more. Once the above irradiation intensity is obtained, the acceleration voltage and speed can be set arbitrarily. The time required for crosslinking by electron beam irradiation depends on the irradiation intensity, but is usually a few seconds to a few minutes. Compared to the 30 minutes to 24 hours required for water crosslinking as mentioned above, electron beam irradiation can significantly reduce the crosslinking time.

[0153] [Application] The silane-modified resin composition and molded articles obtained according to the embodiment of the present invention exhibit excellent flexibility due to component (a), and a stable, high volume resistivity due to component (b), resulting in excellent electrical insulation properties. Therefore, they can be suitably used as insulators and sheaths for electric wires and cables. Furthermore, they can be suitably used for tubes that bundle multiple resin-coated electric wires, as well as for various insulating films, insulating pipes, power boxes, and the like. In particular, they can be used in a wide range of current supply wire fields, including automotive charging cables, automotive cables, electric wire components, electric wire coatings, and busbars. [Examples]

[0154] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist of the invention. The various manufacturing conditions and evaluation result values ​​in the following examples are meant as preferred upper or lower limits in the embodiments of the present invention, and the preferred range may be defined by a combination of the aforementioned upper or lower limits and the values ​​of the following examples or the values ​​of the examples themselves.

[0155] [raw materials] The abbreviations for the raw materials used in the production of the silane-modified resin compositions in the following examples and comparative examples are as follows:

[0156] <Ingredients (a)> TPO-1: Ethylene-α-olefin copolymer Ethylene-1-butene random copolymer Density: 861kg / m 3 MFR (230℃, load 21.18N): 0.9g / 10min TPO-2: Ethylene-α-olefin copolymer Ethylene-1-octene random copolymer Density: 870kg / m 3 MFR (230℃, load 21.18N): 1.0g / 10min TPO-3: Ethylene-α-olefin copolymer Ethylene-1-octene random copolymer Density: 870kg / m 3 MFR (230℃, load 21.18N): 5.0g / 10min • PE-1: High-density polyethylene (HDPE) Density: 941kg / m 3 MFR (190℃, load 21.18N): 2.5g / 10min Flexural modulus: 580 MPa Melting point: 126℃ • PE-2: Linear low-density polyethylene (LLDPE) Density: 920kg / m 3 MFR (190℃, load 21.18N): 0.7g / 10min Flexural modulus: 300 MPa Melting point: 119℃ XLP-1: Silane-modified ethylene-α-olefin copolymer XLP-2: Silane-modified ethylene-α-olefin copolymer • XLP-3: Silane-modified HDPE • MAH-PE-1: Maleic anhydride-modified polyethylene (manufactured by Mitsubishi Chemical Corporation, product name: Modic® 730T) Ethylene-α-olefin copolymer Density: 890kg / m 3 MFR (190℃, 21.2N load): 1.8g / 10min

[0157] <Ingredient (b)> • MDH-1: Magnesium hydroxide (manufactured by Kyowa Chemical Industry Co., Ltd., product name: Kisma (registered trademark) 10A) Average length: 4.00 μm Average thickness: 0.06 μm Average aspect ratio: 70

[0158] <Component (b'): Magnesium hydroxide other than component (b)> • MDH-2: Magnesium hydroxide (manufactured by Kyowa Chemical Industry Co., Ltd., product name: Kisma (registered trademark) 5P) Average length: 0.8 μm Thickness: 0.16 μm Average aspect ratio: 5 • MDH-3: Magnesium hydroxide (manufactured by Kamishima Chemical Industry Co., Ltd., product name Magsies (registered trademark) S6) Average length: 1.0 μm Average thickness: 0.2 μm Average aspect ratio: 4

[0159] <Other ingredients> • KAO-1: Calcined kaolin (manufactured by Shiraishi Calcium Co., Ltd., product name: BURGESS30) • CLA-1: Calcined clay (manufactured by Shiraishi Calcium Co., Ltd., product name: KAOCAL9560)

[0160] <Silanol Condensation Catalyst Masterbatch> • SCC-1: Silanol condensation catalyst masterbatch prepared by the method described below.

[0161] [Preparation of silane-modified olefin polymers XLP-1 to XLP-3] After blending each component in the proportions shown in Table 1, the mixture was extruded using a JSW twin-screw extruder "TEX25" with a gravimetric feeder at 200°C and a screw rotation speed of 300 rpm to obtain pellets of silane-modified olefin polymers XLP-1 to XLP-3, respectively. In Table 1, "Perbutyl (registered trademark) D" is di-t-butyl peroxide manufactured by NOF Corporation.

[0162] [Preparation of Silanol Condensation Catalyst Masterbatch SCC-1] High-density polyethylene (MFR: 5g / 10 min, Density: 953 kg / m³) 3 To 100 parts by mass of (flexural modulus: 820 MPa, melting point: 132°C), 0.1 parts by mass of dioctyl tin dilaurate and 0.1 parts by mass of tetrakis[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane ("Irganox® 1010" manufactured by Ciba Specialty Chemicals Co., Ltd.) were added and mixed. After blending each component, the mixture was extruded using a JSW twin-screw extruder "TEX25" with a gravimetric feeder at 200°C and a screw rotation speed of 300 rpm to obtain pellets of silanol condensation catalyst masterbatch SCC-1.

[0163] [Table 1]

[0164] [Examples 1-6, Comparative Examples 1-11] <Preparation of silane-modified resin composition> Each component other than the silanol condensation catalyst masterbatch was blended in the amounts shown in Tables 2 to 4, and 0.1 parts by mass of tetrakis[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane ("Irganox® 1010" manufactured by Ciba Specialty Chemicals Co., Ltd.) was added as a stabilizer and mixed. The mixture was melt-kneaded at 170°C in a "Mix Lab ML-1000" manufactured by Nippon Spindle Manufacturing Co., Ltd., with a jacket temperature of 80°C and a rotor rotation speed of 90 rpm, then discharged, extruded into a sheet using a mill roll at 160°C, and pelletized using a pelletizer to obtain pellets of the silane-modified resin composition.

[0165] <Manufacturing of evaluation sheets> The pellets obtained above were blended with silanol condensation catalyst masterbatches in the proportions shown in Tables 2 to 4. Using an extrusion molding machine (Thermoplastic Industries Co., Ltd. "TPM-20S model"), an extruded body with a width of 50 mm and a thickness of 1 mm was produced at a cylinder temperature of 190°C and a rotation speed of 60 rpm. Immediately afterward, four of these extruded bodies were stacked and pressed in a compression press at a temperature of 160°C to obtain a 1 mm thick body. Normally, crosslinking occurs in a high-humidity environment, but to avoid the influence of moisture on the obtained body, it was left for two weeks in an environment of 23°C and 50% RH to obtain an evaluation sheet consisting of a silane-crosslinked body.

[0166] <Measurement of volume resistivity> From the evaluation sheet obtained as described above, a sheet-like test piece measuring 1 mm thick x 100 mm wide x 100 mm long was cut out, and its volume resistivity was measured in accordance with JIS K-6723. The results are shown in Tables 2 to 4. The volume resistivity measured in this way is 1 × 10⁻⁶ in various applications such as electric wires and cables. 14 It is preferable that it be Ω·cm or more, 1 × 10 15 A value of Ω·cm or greater is more preferable.

[0167] [Table 2]

[0168] [Table 3]

[0169] [Table 4]

[0170] As shown in Tables 2 to 4, in Examples 1 to 6, which correspond to the silane-modified resin composition of the present invention, the volume resistivity is 1 × 10⁻⁶ in all cases. 15 High electrical insulation properties of Ω·cm or higher are achieved. In contrast, Comparative Examples 1-11 have a volume resistivity of 1 × 10⁻⁶. 15 Electrical insulation of Ω·cm or higher cannot be achieved. In other words, Comparative Examples 1, 6, 9, and 11 contain only component (a) and do not contain component (b), resulting in a volume resistivity of 1 × 10⁻⁶. 15 Although less than Ω·cm, in Examples 1 to 6, in which component (a) was combined with component (b) MDH-1, the volume resistivity was 1 × 10⁻⁶ in all cases. 15 It has achieved a value of Ω·cm or higher. Furthermore, even with similar magnesium hydroxide, comparative examples 2-3, 7, and 10, which contained MDH-2 or MDH-3 that did not satisfy the requirements of component (b) according to the present invention, did not show an improvement in volume resistivity. In Comparative Examples 4, 5, and 8, where calcined kaolin or calcined clay was used instead of component (b), a sufficient improvement in volume resistivity was not achieved. [Industrial applicability]

[0171] The silane-modified resin composition according to the embodiment of the present invention can achieve high electrical insulation without affecting appearance or other physical properties, unlike conventional silane-modified resin compositions that were highly flexible but could not obtain high volume resistivity. By improving electrical insulation, it can be advantageously used in a wide range of fields, including automotive wires, robot cables, and industrial cables.

Claims

1. A silane-modified resin composition comprising the following component (a) and the following component (b), wherein the amount of component (b) is 0.1 to 10 parts by mass per 100 parts by mass of component (a). Component (a): Olefin polymer component in which at least a portion of the olefin polymer is modified with an unsaturated silane compound, resulting in a silane-modified olefin polymer. Component (b): Magnesium hydroxide with an average major axis of 0.5–10 μm, an average thickness of 0.01–0.5 μm, and an average aspect ratio of 10–100 (ratio of average major axis to average thickness).

2. The olefin polymer of component (a) has a density of 860 to 910 kg / m³ ３ The silane-modified resin composition according to claim 1, comprising an ethylene-α-olefin polymer within the range.

3. The silane-modified olefin polymer of component (a) has a density of 860 to 910 kg / m³. ３ The silane-modified resin composition according to claim 2, wherein the ethylene-α-olefin polymer in the range is a silane-modified olefin polymer graft-modified with an unsaturated silane compound.

4. The silane-modified resin composition according to claim 1, wherein component (a) comprises an olefin polymer modified with a polar group.

5. Furthermore, the silane-modified resin composition according to claim 1, further comprising styrene-based rubber.

6. Furthermore, the silane-modified resin composition according to claim 1, further comprising olefin rubber.

7. The silane-modified resin composition according to claim 1, further comprising one or more flame retardants selected from the group consisting of phosphorus-based flame retardants, metal hydroxide-based flame retardants with an average aspect ratio of 6 or less, and bromine-based flame retardants.

8. Furthermore, the silane-modified resin composition according to any one of claims 1 to 7 contains a silanol condensation catalyst.

9. A molded article obtained by crosslinking the silane-modified resin composition described in claim 8 with silane.

10. A molded article according to claim 9, comprising a mixture of a resin composition containing at least component (a) and a masterbatch containing component (b) and a silanol condensation catalyst.

11. A molded article obtained by electron beam crosslinking a silane-modified resin composition according to any one of claims 1 to 8.

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