Modified elastomer composition, crosslinked elastomer composition, and molded article

Abstract

To provide a modified elastomer composition, a crosslinked elastomer composition, and a molded article that have high ductility, excellent moldability (specifically, extrusion moldability), and high temperature resistance. [Solution] A modified elastomer composition comprising: (A) ethylene-α-olefin copolymer rubber, (B) propylene resin, (C) at least one of styrene-conjugated diene block copolymer and hydrogenated styrene-conjugated diene block copolymer, and (D) an unsaturated silane compound, and grafted with (E) a peroxide, wherein when the total of components (A) to (C) is 100 parts by mass, component (A) is 30 parts by mass or more and 75 parts by mass or less, component (B) is 14 parts by mass or more and 60 parts by mass or less, and the mass ratio of the content of component (C) to the content of component (B) (component (C) / component (B)) is 0.25 or more and 1.00 or less.

Description

[Technical Field]

[0001] The present invention relates to a modified elastomer composition, a crosslinked elastomer composition, and a molded article. [Background technology]

[0002] Thermoplastic elastomers are elastomers that soften and become fluid when heated, and exhibit rubber-like elasticity when cooled. Thermoplastic elastomers have similar moldability to thermoplastic resins, as well as rubber-like elasticity and are recyclable, making them widely used in applications such as automotive parts, building components, medical components, wire insulation, and general merchandise.

[0003] Thermoplastic elastomers are modified to have properties suitable for various applications. For example, automotive elastomer components such as glass run channels, weatherstrips, rubber hoses, and wiper blade rubber, as well as industrial rubber elastomer products such as packings, gaskets, and vibration-damping rubber, require low compression set from the standpoint of sealing, adhesion, and resistance to deformation. However, thermoplastic elastomers contain thermoplastic resins such as polyolefins to ensure thermoplasticity, resulting in insufficient compression set properties. Therefore, modifications are made to impart compression set properties to thermoplastic elastomers.

[0004] Examples of thermoplastic elastomer compositions with improved compression set properties include ethylene-α-olefin-non-conjugated diene copolymer rubber; ethylene-α-olefin copolymer rubber that does not contain non-conjugated diene units; styrene-based thermoplastic elastomers; polyethylene, polypropylene, or propylene-α-olefin copolymers; modified elastomer compositions obtained by graft-modifying compositions containing unsaturated silane compounds with peroxides, or crosslinked elastomer compositions obtained by further crosslinking these (see Patent Document 1). Patent Document 1 describes that the modified elastomer composition and the crosslinked elastomer composition can be used to obtain a molded article that combines compression set characteristics equivalent to those of thermosetting rubber with the same ease of moldability as that of thermoplastic elastomers. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2018-154815 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] However, the modified elastomer composition and crosslinked elastomer composition described in Patent Document 1 lacked sufficient flexibility and extruded appearance, and further improvements were needed. Furthermore, with the recent rise in global temperatures, resin molded products are expected to be used in high-temperature environments. For example, vehicles such as automobiles are directly exposed to sunlight, causing temperatures to rise easily, especially in the summer, and the resin molded products incorporated into these vehicles are also exposed to high temperatures. Elastomer components are prone to degradation and may lose strength in high-temperature environments exceeding 70°C, so thermoplastic elastomers are required to have high-temperature resistance.

[0007] Therefore, the object of the present invention is to provide a modified elastomer composition, a crosslinked elastomer composition, and a molded article that have high ductility, excellent moldability (specifically, extrusion moldability), and high temperature resistance. [Means for solving the problem]

[0008] As a result of diligent research to solve the above problems, the inventors have found that a modified elastomer composition comprising ethylene-α-olefin copolymer rubber, a propylene resin, a styrene-conjugated diene block copolymer and / or its hydrogenated product, and an unsaturated silane compound, grafted with a peroxide, wherein the composition contains ethylene-α-olefin copolymer rubber and propylene resin in specific ranges, and the mass ratio of the styrene-conjugated diene block copolymer and / or its hydrogenated product to the propylene resin content is within a specific range, can solve the above problems, and have completed the present invention.

[0009] One aspect of the present invention is a modified elastomer composition comprising the following components (A) to (D) and grafted with the following component (E), wherein when the total amount of components (A) to (C) is 100 parts by mass, component (A) is 30 parts by mass or more and 75 parts by mass or less, component (B) is 14 parts by mass or more and 60 parts by mass or less, and the mass ratio of the content of component (C) to the content of component (B) (component (C) / component (B)) is 0.25 or more and 1.00 or less. Component (A): Ethylene-α-olefin copolymer rubber Component (B): Propylene resin Component (C): At least one of a styrene-conjugated diene block copolymer and a hydrogenated styrene-conjugated diene block copolymer. Component (D): Unsaturated silane compound Ingredient (E): Peroxide

[0010] Aspect 2 of the present invention is a modified elastomer composition of Aspect 1 in which, when the total of components (A) to (C) is 100 parts by mass, component (C) is contained in an amount of 5 parts by mass or more and 40 parts by mass or less.

[0011] A third aspect of the present invention is a modified elastomer composition according to aspect 1 or 2, wherein component (C) is a styrene-conjugated diene block copolymer.

[0012] Aspect 4 of the present invention is a modified elastomer composition according to any one of Aspects 1 to 3, wherein the end melting peak temperature measured by a differential scanning calorimeter (DSC) of the component (A) is 115°C or higher.

[0013] Aspect 5 of the present invention is a modified elastomer composition according to any one of Aspects 1 to 4, wherein the component (D) is a compound represented by the following formula (1). RSi(R’)3···(1) (In formula (1), R is an ethylenically unsaturated hydrocarbon group, R’ are each independently a hydrocarbon group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms, and at least one of R’ is an alkoxy group having 1 to 10 carbon atoms.)

[0014] Aspect 6 of the present invention is a modified elastomer composition according to any one of Aspects 1 to 5, further comprising component (F): a softening agent for hydrocarbon rubber, in an amount of 1 part by mass or more and 200 parts by mass or less based on 100 parts by mass in total of the component (A) and the component (B).

[0015] Aspect 7 of the present invention is a crosslinked elastomer composition obtained by crosslinking a modified elastomer composition according to any one of Aspects 1 to 6 with component (G): a silanol catalyst.

[0016] Aspect 8 of the present invention is a crosslinked elastomer composition according to Aspect 7, wherein the durometer A hardness in JIS K6253 (2012) (Duro-A) is 75 or higher.

[0017] Aspect 9 of the present invention is a molded article containing a modified elastomer composition according to any one of Aspects 1 to 6.

[0018] Aspect 10 of the present invention is a molded article according to Aspect 9, which is a hose for automotive parts.

[0019] Aspect 11 of the present invention is a molded article containing the crosslinked elastomer composition according to Aspect 7 or 8.

[0020] Aspect 12 of the present invention is a molded body of the present invention that is a hose for an automobile part, in which case the molded body is the present invention. [Effects of the Invention]

[0021] According to the present invention, it is possible to provide a modified elastomer composition and a crosslinked elastomer composition that can produce molded articles with excellent moldability and high temperature resistance, and a molded article using the same. [Modes for carrying out the invention]

[0022] Embodiments of the present invention will be described in detail below, but the present invention is not limited to the following description and can be modified and implemented as appropriate without departing from the spirit of the invention.

[0023] [Modified elastomer composition] The modified elastomer composition of the present invention comprises the following components (A) to (D) and is grafted with the following component (E), and more preferably comprises the following component (F). Component (A): Ethylene-α-olefin copolymer rubber Component (B): Propylene resin Component (C): At least one of a styrene-conjugated diene block copolymer and a hydrogenated styrene-conjugated diene block copolymer. Component (D): Unsaturated silane compound Ingredient (E): Peroxide Ingredient (F): Hydrocarbon rubber softener Furthermore, the modified elastomer composition of the present invention contains, when the total amount of components (A) to (C) is 100 parts by mass, 30 parts by mass or more and 75 parts by mass or less of component (A), and 14 parts by mass or more and 60 parts by mass or less of component (B), and the mass ratio of the content of component (C) to the content of component (B) (component (C) / component (B)) is 0.25 or more and 1.00 or less.

[0024] <Mechanism> The mechanism by which the modified elastomer composition of the present invention yields molded articles with excellent moldability, specifically extrusion moldability and high-temperature resistance, is presumed to be as follows. Components (A) and (C) are grafted by components (D) and (E), resulting in high rubber elasticity. The inclusion of component (B) improves ductility and provides good extrudeability (molding stability). Furthermore, the inclusion of component (C) improves flexibility, resulting in a good appearance for molded articles containing the modified elastomer composition of the present invention. When the total amount of components (A) to (C) is 100 parts by mass, the content of component (A) is 30 parts by mass or more and 75 parts by mass or less, the content of component (B) is 14 parts by mass or more and 60 parts by mass or less, and the content ratio of component (C) / component (B) is 0.25 or more and 1.00 or less. This balances appropriate flexibility with sufficient heat resistance, resulting in a molded article that possesses high-temperature resistance and can suppress strength reduction in high-temperature environments. Furthermore, the inclusion of component (F) further improves the flexibility of the modified elastomer composition and can impart a good extruded appearance.

[0025] <Component (A): Ethylene-α-olefin copolymer rubber> Component (A) is ethylene-α-olefin copolymer rubber. Ethylene-α-olefin copolymer rubber is a copolymer that contains the most ethylene units among its constituent units, and known ethylene-α-olefin copolymer rubbers can be used as appropriate. The ethylene unit content of the ethylene-α-olefin copolymer rubber is preferably 60% by mass or more and 99% by mass or less, and more preferably 60% by mass or more and 85% by mass or less. When the ethylene unit content is within the above range, it is easier to obtain a modified elastomer composition with excellent mechanical strength and rubber elasticity.

[0026] The density of the ethylene-α-olefin copolymer rubber component (A) used in this invention (measured according to JIS K6922-1,2:1997) is preferably 0.855 g / cm³. 3 More than 0.900g / cm 3 The following is the result: 0.860 g / cm³ 3 More than 0.895g / cm3 It is more preferable that the following is the case: 0.860 g / cm³ 3 More than 0.890g / cm 3 It is even more preferable that the following is the case: 0.860 g / cm³ 3 More than 0.880g / cm 3 The following are particularly preferable: If the density is below the above upper limit, it tends to be flexible and have excellent resistance to compression set. If the density is above the above lower limit, it has excellent tensile strength.

[0027] Specific examples of the ethylene-α-olefin copolymer rubber used in the present invention include copolymer rubbers of ethylene, such as ethylene-propylene copolymer, ethylene-1-butene copolymer, ethylene-4-methyl-1-pentene copolymer, ethylene-1-hexene copolymer, and ethylene-1-octene copolymer, and one or more α-olefins having 3 to 10 carbon atoms.

[0028] The type of catalyst used in the production of ethylene-α-olefin copolymer rubber is not particularly limited, but examples include Ziegler-Natta catalysts and metallocene catalysts. Among these, ethylene-α-olefin copolymer rubber produced using a metallocene catalyst is preferred.

[0029] The ethylene-α-olefin copolymer rubber used in this invention preferably has a melting termination peak temperature (hereinafter sometimes referred to as the "melting termination point") of 115°C or higher, as measured by a differential scanning calorimeter (DSC). A melting termination point of 115°C or higher allows the shape to be maintained by crystallization even at high temperatures. From this viewpoint, a melting termination point of ethylene-α-olefin copolymer rubber of 115°C or higher, and particularly 117°C or higher, is preferred. However, if the melting termination point of ethylene-α-olefin copolymer rubber is excessively high, there is a risk of unmelted material during molding heating or premature crystallization (melt fracture) during molding cooling, resulting in poor appearance. Therefore, the melting termination point of ethylene-α-olefin copolymer rubber is usually 145°C or lower. The melting termination point of ethylene-α-olefin copolymer rubber is measured by the method described in the Examples section below.

[0030] The content of each constituent unit of component (A) can be determined by infrared spectroscopy and NMR spectroscopy. The content of each constituent unit of component (B), described below, can be determined by infrared spectroscopy.

[0031] The melt flow rate (MFR) of the ethylene-α-olefin copolymer rubber used in the present invention is the melt flow rate (MFR) measured under conditions of 190°C and 21.2N load in accordance with JIS K7210 (2014), and is preferably 0.01 g / 10 min or more and 30 g / 10 min or less. By setting the upper limit of the MFR of the ethylene-α-olefin copolymer rubber used in the present invention to 30 g / 10 min or less, flexibility is increased and good sealing properties can be maintained. Furthermore, by setting the lower limit of the MFR to 0.01 g / 10 min or more, it is possible to suppress the deterioration of productivity due to the increase in resin pressure when manufacturing the modified elastomer composition of the present invention by melt extrusion. From these viewpoints, the MFR of the ethylene-α-olefin copolymer rubber is more preferably 0.1 g / 10 min or more, and more preferably 20 g / 10 min or less.

[0032] The ethylene-α-olefin copolymer rubber used in this invention can be obtained as a commercially available product. For example, the appropriate product can be selected and used from the ENGAGE (registered trademark) series manufactured by Dow Chemical, the KERNER (registered trademark) series manufactured by Nippon Polyethylene Co., Ltd., the INFUSE (registered trademark) series manufactured by Dow Chemical, the TAFMER (registered trademark) series manufactured by Mitsui Chemicals, and the EVOLU (registered trademark) series manufactured by Mitsui Chemicals.

[0033] The ethylene-α-olefin copolymer rubber of component (A) can be used alone or in any combination and ratio of two or more types.

[0034] <Component (B): Propylene resin> The propylene resin of component (B) used in the present invention is a propylene resin in which the content of propylene units relative to the total monomer units contained in the resin is 40% by mass or more and 100% by mass or less, and preferably the content of ethylene units is 0% by mass or more and 50% by mass or less.

[0035] The type of propylene resin in component (B) is not particularly limited, and any of the following can be used: propylene homopolymer, propylene random copolymer, propylene block copolymer, etc. Furthermore, one of these may be used, or two or more may be used in combination.

[0036] When component (B) is a propylene random copolymer or a propylene block copolymer, examples of monomers copolymerized with propylene include one or more α-olefins such as ethylene, 1-butene, 2-methylpropylene, 1-pentene, 3-methyl-1-butene, 1-hexene, 4-methyl-1-pentene, and 1-octene. Furthermore, when component (B) is a propylene block copolymer, examples include propylene block copolymers obtained by multi-step polymerization, more specifically, propylene block copolymers obtained by polymerizing polypropylene in the first step and propylene-ethylene copolymer in the second step.

[0037] The propylene unit content in the polypropylene resin of component (B) is 40% by mass or more, preferably 50% by mass or more. A propylene unit content above the above lower limit tends to result in good moldability and molded appearance. On the other hand, there is no particular upper limit to the propylene unit content, and it is usually 100% by mass.

[0038] The melt flow rate (MFR) of the propylene resin of component (B) is measured according to JIS K 7210 (2014) at 230°C and a load of 21.2 N, and is usually 0.01 g / 10 min or more, preferably 0.1 g / 10 min or more, more preferably 0.2 g / 10 min or more, and even more preferably 0.3 g / 10 min or more from the viewpoint of fluidity. On the other hand, it is usually 100 g / 10 min or less, and from the viewpoint of moldability and high-temperature strength, it is preferably 30 g / 10 min or less, more preferably 20 g / 10 min or less, and even more preferably 10 g / 10 min or less. In other words, the melt flow rate (MFR) of the propylene resin of component (B) is preferably in the range of 0.01 g / 10 min or more and 100 g / 10 min or less.

[0039] As a method for producing the propylene resin of component (B), known polymerization methods using known olefin polymerization catalysts can be used. For example, a multi-stage polymerization method using a Ziegler-Natta catalyst can be used. This multi-stage polymerization method can include slurry polymerization, solution polymerization, bulk polymerization, gas-phase polymerization, etc., and two or more of these may be combined for production.

[0040] The propylene resin component (B) is available commercially. For example, Prim Polypro® (manufactured by Prime Polymer Inc.), Sumitomo Noblen® (manufactured by Sumitomo Chemical Co., Ltd.), Propylene-Ethylene Random Copolymer (manufactured by Sun Allomer Co., Ltd.), Novatec® PP (manufactured by Nippon Polypropylene Co., Ltd.), Moplen® (manufactured by LyondellBasell Inc.), Adflex® (manufactured by Adflex®), Hiflex® (manufactured by Hifax®), ExxonMobil PP (manufactured by ExxonMobil Inc.), Formolene® (manufactured by Formosa Plastics Inc.), Borealis PP (manufactured by Borealis Inc.), SEETEC PP (manufactured by LG Chemical Inc.), ASI POLYPROPYLENE (manufactured by A. Schulman Inc.), INEOS PP (manufactured by INEOS Olefins & Polymers Inc.), Braskem PP (manufactured by Braskem Inc.), Samsung Total Petrochemicals Inc., Sabic® PP (manufactured by Sabic Inc.), TOTAL PETROCHEMICALS Polypropylene can be selected and used from the following options: YUPLENE® manufactured by SK Corporation.

[0041] The propylene resin of component (B) can be used alone or in any combination and ratio of two or more types.

[0042] <Component (C): Styrene-conjugated diene block copolymer and / or hydrogenated thereof> The modified elastomer composition of the present invention contains at least one of a styrene-conjugated diene block copolymer and a hydrogenated styrene-conjugated diene block copolymer as component (C). By containing a styrene-conjugated diene block copolymer and / or its hydrogenated counterpart, the flexibility, high-temperature strength, and moldability of the modified elastomer composition are improved, and the decrease in compression set can be suppressed.

[0043] The styrene-conjugated diene block copolymer is preferably a block copolymer having at least two polymer blocks P derived from a vinyl aromatic compound and at least one polymer block Q derived from a conjugated diene.

[0044] The vinyl aromatic monomers constituting block P are not particularly limited, but styrene derivatives such as styrene and α-methylstyrene are preferred. Among these, styrene is preferred as the main component. Here, "main component" in component (C) means that the content of the said constituent unit in the block is 50% by mass or more. Note that block P may also contain monomers other than vinyl aromatic compounds as raw materials.

[0045] Examples of monomers other than the vinyl aromatic compounds mentioned above include ethylene and α-olefins. Furthermore, when block P contains monomers other than the vinyl aromatic compounds as raw materials, their content is 50% by mass or less, preferably 40% by mass or less. Having a content of monomers other than the vinyl aromatic compounds within this range tends to result in good heat resistance and flexibility.

[0046] The conjugated dienes of the monomers constituting block Q are not particularly limited, but it is preferable that they be mainly butadiene and / or isoprene, and more preferably that they be mainly butadiene. Block Q may also contain monomers other than conjugated dienes as raw materials.

[0047] Examples of monomers other than the conjugated dienes mentioned above include isobutylene and styrene. Furthermore, when block Q contains monomers other than the conjugated dienes as raw materials, their content is 50% by mass or less, preferably 40% by mass or less. Bleed-out tends to be suppressed when the content of monomers other than the conjugated dienes is within this range.

[0048] The styrene-conjugated diene block copolymer preferably has a structure having at least two polymer blocks P and at least one polymer block Q, and may be linear, branched, radial, etc., but is preferably a block copolymer represented by the following formula (2) or (3).

[0049] P-(Q-P) m ···(2) (P-Q) n ···(3) (In the formula, P represents the polymer block P, Q represents the polymer block Q, m represents an integer of 1 or more and 5 or less, and n represents an integer of 2 or more and 5 or less.)

[0050] In formula (2) or formula (3), m and n are preferably larger in terms of lowering the order-disorder transition temperature as a rubbery polymer, but are preferably smaller in terms of ease of production and cost.

[0051] The mass ratio of block P to block Q constituting the styrene-conjugated diene block copolymer is arbitrary, but from the viewpoint of the good touch feeling of the modified elastomer composition of the present invention, it is preferable that there is more block P, while from the viewpoints of flexibility, bleed-out suppression, and compression set resistance, it is preferable that there is less block P.

[0052] The content of block P in the styrene-conjugated diene block copolymer is preferably 10% by mass or more, more preferably 15% by mass or more, still more preferably 20% by mass or more, and is preferably 60% by mass or less, more preferably 50% by mass or less, still more preferably 45% by mass or less. That is, the content of block P in the styrene-conjugated diene block copolymer is preferably in the range of 10% by mass to 60% by mass.

[0053] The hydrogenated styrene-conjugated diene block copolymer is preferably a hydrogenated block copolymer obtained by hydrogenating a block copolymer having at least two polymer blocks P derived from the vinyl aromatic compound described above and at least one polymer block Q derived from a conjugated diene. More specifically, it is preferably a hydrogenated block copolymer in which hydrogen is added to the double bond of block Q of the block copolymer. The hydrogenation rate of block Q is not particularly limited, but is preferably 80% by mass or more and 100% by mass or less, more preferably 90% by mass or more and 100% by mass or less.

[0054] In the hydrogenated block copolymer represented by formula (2) and / or formula (3) above, when block Q is composed solely of butadiene, it is preferable for the proportion of 1,2-bonds (1,2-addition structures) in the microstructure of block Q to be 20% by mass or more and 90% by mass or less in order to maintain its properties as an elastomer. To obtain flexibility and good mechanical strength, it is more preferable for the proportion of 1,2-bonds in the microstructure of block Q to be 50% by mass or more and 90% by mass or less, and even more preferable for it to be 60% by mass or more and 80% by mass or less.

[0055] Examples of styrene-conjugated diene block copolymers and / or hydrogenated thereof include styrene-butadiene block copolymers and / or hydrogenated thereof, styrene-butadiene-styrene block copolymers and / or hydrogenated thereof, styrene-isoprene-styrene block copolymers and / or hydrogenated thereof, styrene-butadiene-isoprene block copolymers and / or hydrogenated thereof, and styrene-isoprene-butadiene-styrene block copolymers and / or hydrogenated thereof.

[0056] Examples of hydrogenated styrene-butadiene block copolymers include styrene-butadiene-butylene copolymer (SBB), styrene-ethylene-butylene copolymer (SEB), and styrene-ethylene-butylene copolymer (SEB). Examples of hydrogenated styrene-butadiene-styrene block copolymers include styrene-ethylene-butylene-styrene copolymer (SEBS). Examples of hydrogenated materials for styrene-isoprene-styrene block copolymers include styrene-ethylene-propylene-styrene copolymer (SEPS). Examples of hydrogenated styrene-isoprene-butadiene-styrene block copolymers include styrene-ethylene-ethylene-propylene-styrene copolymer (SEEPS).

[0057] Among these, from the viewpoint of high-temperature resistance, styrene-conjugated diene block copolymers and / or hydrogenated thereof are preferred, as are styrene-butadiene-styrene block copolymers and their hydrogenated versions, and styrene-isoprene-butadiene-styrene block copolymers and their hydrogenated versions.

[0058] The styrene-conjugated diene block copolymer and / or hydrogenated thereof used in the present invention preferably has a melt flow rate (MFR) of 10 g / 10 min or less, measured at a temperature of 200°C and a load of 49 N in accordance with JIS K7210 (2014). By setting the upper limit of the MFR of component (C) used in the present invention to 10 g / 10 min or less, excessive compression set can be suppressed, good rubber elasticity can be maintained, and high-temperature strength can be further improved. Furthermore, the MFR is more preferably 5 g / 10 min or less, and even more preferably 1 g / 10 min or less. The MFR of component (C) used in the present invention may be 0 g / 10 min.

[0059] The density (measured according to JIS K6922-1,2:1997) of the styrene-conjugated diene block copolymer and / or hydrogenated thereof used in the present invention is preferably 0.88 g / cm³. 3 More than 1.00g / cm 3 The following is the value: 0.89 g / cm³ 3 More than 0.98g / cm 3 It is more preferable that the following is the case: 0.89 g / cm³ 3 More than 0.96g / cm3 The following are particularly preferable: If the density is below the above upper limit, it tends to be flexible and have excellent compression set. If the density is above the above lower limit, it tends to have excellent heat resistance.

[0060] The method for producing component (C) in the present invention is not particularly limited and can be any method as long as the above-described structure and physical properties are obtained. For example, a block copolymer can be obtained by performing block polymerization in an inert solvent using a lithium catalyst or the like, as described in Japanese Patent Publication No. 40-23798. Furthermore, hydrogenation of the block copolymer can be carried out in an inert solvent in the presence of a hydrogenation catalyst, as described in Japanese Patent Publication No. 42-8704, Japanese Patent Publication No. 43-6636, Japanese Unexamined Patent Publication No. 59-133203 and Japanese Unexamined Patent Publication No. 60-79005, etc.

[0061] Component (C) is available commercially. Examples of commercially available components (C) include Kraton Polymer's "Kraton®-G series," Kuraray's "Septon® series" and "Hybler® series," Asahi Kasei's "Asaprene® series" and "ToughTec® series," and TSRC's "TAIPOL series." You can select and use the appropriate product from among these.

[0062] Component (C) may be used alone, or two or more components with different block compositions and physical properties may be mixed and used.

[0063] <Component (D): Unsaturated silane compound> The unsaturated silane compound of component (D) used in the present invention is not limited, but an unsaturated silane compound represented by the following formula (1) is preferably used. RSi(R')3···(1)

[0064] In formula (1) above, R is an ethylenically unsaturated hydrocarbon group, and R' are independently a hydrocarbon group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms, and at least one of R' is an alkoxy group having 1 to 10 carbon atoms.

[0065] In formula (1), R is preferably an ethylenically unsaturated hydrocarbon group having 2 to 10 carbon atoms, and more preferably an ethylenically unsaturated hydrocarbon group having 2 to 6 carbon atoms. Specifically, examples include alkenyl groups such as vinyl groups, propenyl groups, butenyl groups, and cyclohexenyl groups.

[0066] In formula (1), R' is preferably a hydrocarbon group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms, and more preferably a hydrocarbon group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms. Furthermore, at least one of R' is preferably an alkoxy group having 1 to 6 carbon atoms, and more preferably an alkoxy group having 1 to 4 carbon atoms. The hydrocarbon group of R' having 1 to 10 carbon atoms may be an aliphatic group, an alicyclic group, or an aromatic group, but it is preferable that it be an aliphatic group. Furthermore, the alkoxy group of R' having 1 to 10 carbon atoms may be linear, branched, or cyclic, but it is preferable that it be linear or branched. When R' is a hydrocarbon group, specific examples include alkyl groups represented by methyl, ethyl, isopropyl, t-butyl, n-butyl, i-butyl, cyclohexyl groups, etc., or aryl groups represented by phenyl groups, etc. When R' is an alkoxy group, specific examples include methoxy, ethoxy, isopropoxy, and β-methoxyethoxy groups.

[0067] When an unsaturated silane compound is represented by formula (1), at least one of the three R' groups is an alkoxy group, but it is preferable that two of the R' groups are alkoxy groups, and it is more preferable that all of the R' groups are alkoxy groups.

[0068] As for the unsaturated silane compound, vinyltrialkoxysilanes, such as vinyltrimethoxysilane, vinyltriethoxysilane, and propenyltrimethoxysilane, which are represented by formula (1), are preferred. This is because the vinyl group enables the modification of component (A) into ethylene-α-olefin copolymer rubber, and the alkoxysilyl group allows the crosslinking reaction described later to proceed. That is, the alkoxysilyl group introduced by graft modification of the ethylene-α-olefin copolymer rubber with the unsaturated silane compound reacts with water in the presence of the silanol catalyst (component (G)) described later to undergo hydrolysis and generate silanol groups. The silanol groups then undergo dehydration condensation, causing the ethylene-α-olefin copolymer rubbers to bond together and a crosslinking reaction to occur. Note that these unsaturated silane compounds may be used individually or in combination of two or more.

[0069] <Component (E): Peroxide> Examples of peroxides of component (E) include hydroperoxides, dialkyl peroxides, diacyl peroxides, peroxyesters, and organic peroxides included in the ketone peroxide group, specifically those listed below.

[0070] The hydroperoxide group includes cumene hydroperoxide and t-butyl hydroperoxide, the dialkylperoxide group includes dicumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, 2,5-dimethyl-2,5-di(t-butylperoxyl)-3-hexine, and di(2-t-butylperoxyisopropyl)benzene, the diacylperoxide group includes lauryl peroxide and benzoyl peroxide. The peroxyester group includes t-butyl peroxyacetate, t-butyl peroxybenzoate, and t-butylperoxyisopropyl carbonate, the ketone peroxide group includes cyclohexanone peroxide, etc.

[0071] Of these, radical generators with high thermal decomposition temperatures are preferred from the viewpoint of graft reaction in the melt-kneading process by extruder when producing the modified elastomer composition of the present invention. From this viewpoint, di-t-butyl peroxide, di(2-t-butylperoxyisopropyl)benzene, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, and dicumyl peroxide are preferred.

[0072] The peroxide of component (E) can be used alone or in any combination and ratio of two or more types.

[0073] <Ingredient (F): Hydrocarbon-based rubber softener> The modified elastomer composition of the present invention may contain a hydrocarbon-based rubber softener as component (F) from the viewpoint of increasing flexibility and improving processability, fluidity, and oil resistance.

[0074] Examples of hydrocarbon-based rubber softeners for component (F) 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.

[0075] Mineral oil-based rubber softeners are generally mixtures of aromatic hydrocarbons, naphthenic hydrocarbons, and paraffinic hydrocarbons. Those in which paraffinic hydrocarbons account for 50% or more of the total carbon atoms are called paraffinic oils, those in which naphthenic hydrocarbons account for 30% to 45% of the total carbon atoms are called naphthenic oils, and those in which aromatic hydrocarbons account for 35% or more of the total carbon atoms are called aromatic oils. Among these, liquid hydrocarbon-based rubber softeners that are liquid at room temperature (23±2℃) are preferred, and liquid paraffinic oils that are liquid at room temperature are more preferred. By using a liquid hydrocarbon-based rubber softener as a softener for hydrocarbon-based rubber, the flexibility and elasticity of the modified elastomer composition of the present invention can be increased, and the processability and fluidity tend to improve dramatically.

[0076] While there are no particular limitations on paraffin-based oils, those with a kinematic viscosity at 40°C of 10 cSt (centistokes) or higher, preferably 20 cSt or higher, and typically 800 cSt or lower, preferably 600 cSt or lower, are preferably used. Furthermore, the pour point is typically -40°C or higher, preferably -30°C or higher, and preferably 0°C or lower. In addition, the flash point (COC) is typically 200°C or higher, preferably 250°C or higher, and typically 400°C or lower, preferably 350°C or lower, are preferably used. In other words, the kinematic viscosity of the paraffin-based oil at 40°C is preferably in the range of 10 cSt to 800 cSt, and the flash point is preferably in the range of 200°C to 400°C.

[0077] The hydrocarbon-based rubber softener of component (F) can be used alone or in any combination and ratio of two or more types.

[0078] [Cross-linked elastomer composition] The crosslinked elastomer composition of the present invention is obtained by crosslinking the modified elastomer composition of the present invention with component (G): silanol catalyst.

[0079] <Component (G): Silanol catalyst> By incorporating component (G) silanol catalyst into the modified elastomer composition of the present invention, a crosslinked elastomer composition can be obtained by causing an intermolecular crosslinking reaction in the modified elastomer composition. Specifically, the alkoxysilyl groups introduced by graft modification into component (A) ethylene-α-olefin copolymer rubber, and preferably further into component (C) styrene-conjugated diene block copolymer and / or its hydrogenated product, react with water in the presence of the silanol catalyst to hydrolyze and generate silanol groups. Furthermore, the silanol groups undergo dehydration condensation, causing a crosslinking reaction to proceed, and the modified ethylene-α-olefin copolymer rubber, styrene-conjugated diene block copolymer and / or its hydrogenated product bond to each other to produce a crosslinked elastomer composition with excellent heat resistance.

[0080] Examples of silanol catalysts (G) that can be used in the present invention include one or more compounds selected from the group consisting of metal organic acid salts, titanates, borates, organic amines, ammonium salts, phosphonium salts, inorganic acids and organic acids, and inorganic acid esters.

[0081] Examples of metal organic salts include dibutyltin dilaurate, dioctyltin dilaurate, dibutyltin diacetate, dibutyltin dioctoate, stannous acetate, stannous octanoate, cobalt naphthenate, lead octoate, lead naphthenate, zinc octoate, zinc caprylate, iron 2-ethylhexanoate, iron octoate, and iron stearate. Examples of titanates include tetrabutyl titanate, tetranonyl titanate, and bis(acetylacetonitrile) di-isopropyl titanate. Examples of organic amines include ethylamine, dibutylamine, hexylamine, triethanolamine, tetramethylguanidine, and pyridine. Examples of ammonium salts include ammonium carbonate and tetramethylammonium hydroxide. Examples of phosphonium salts include tetramethylphosphonium hydroxide. Examples of inorganic and organic acids include sulfonic acids such as sulfuric acid, hydrochloric acid, acetic acid, stearic acid, maleic acid, toluenesulfonic acid, and alkylnaphthylsulfonic acid. Examples of inorganic acid esters include phosphate esters such as ethylhexyl phosphate.

[0082] Among these, preferred examples include metal organic salts, sulfonic acids, and phosphate esters, and more preferably tin metal carboxylates (e.g., dioctyl tin dilaurate), alkyl naphthyl sulfonic acid, and ethylhexyl phosphate esters.

[0083] The silanol catalysts listed above may be used individually or in combination of two or more.

[0084] The silanol catalyst is preferably used as a masterbatch containing a polyolefin and the silanol catalyst. Examples of polyolefins that can be used in this masterbatch include polyethylene, polypropylene, and ethylene-α-olefin copolymers.

[0085] Examples of polyethylene include (branched or linear) ethylene homopolymers such as low, medium, and high-density polyethylene; ethylene-α-olefin copolymers such as ethylene-propylene copolymer, ethylene-1-butene copolymer, ethylene-4-methyl-1-pentene copolymer, ethylene-1-hexene copolymer, and ethylene-1-octene copolymer; and ethylene-based copolymer resins such as ethylene-vinyl acetate copolymer, ethylene-(meth)acrylic acid copolymer, and ethylene-(meth)acrylic acid ester copolymer.

[0086] Among these, in the present invention, high-pressure low-density polyethylene, high-density polyethylene, and ethylene-α-olefin copolymers, which have an excellent balance of heat resistance and strength, are preferred. More preferably, the ethylene-α-olefin copolymer is an ethylene-α-olefin copolymer such as ethylene-1-butene copolymer, ethylene-4-methyl-1-pentene copolymer, ethylene-1-hexene copolymer, or ethylene-1-octene copolymer. It is even more preferable that this ethylene-α-olefin copolymer is copolymerized in a range of 2% to 60% by mass of one or more α-olefins and 40% to 98% by mass of ethylene. In the masterbatch of the silanol catalyst, only one of these polyolefins may be used, or two or more may be blended and used.

[0087] When using a silanol catalyst as a masterbatch containing a polyolefin and the silanol catalyst, there are no particular restrictions on the content of the silanol catalyst in the masterbatch, but it is generally preferable to have a content of 0.1% by mass or more and 5.0% by mass or less.

[0088] Commercially available masterbatches containing silanol catalysts can be used; for example, Mitsubishi Chemical Corporation's "LZ082" and "LZ033" can be used.

[0089] <Composition Ratio> The modified elastomer composition of the present invention contains, when the total amount of components (A), (B), and (C) is 100 parts by mass, 30 parts by mass or more and 75 parts by mass or less of component (A), and 14 parts by mass or more and 60 parts by mass or less of component (B).

[0090] The content of component (A) is in the range of 30 parts by mass or more and 75 parts by mass or less per 100 parts by mass of the total of components (A) to (C). When the content of component (A) is 30 parts by mass or more, the flexibility of the modified elastomer composition can be maintained. Furthermore, when the content of component (A) is 75 parts by mass or less, the hardness of the resulting molded article can be maintained, resulting in excellent high-temperature resistance, and the reduction in strength can be suppressed even when the molded article is exposed to a high-temperature environment. From this viewpoint, the content of component (A) is preferably 35 parts by mass or more and 70 parts by mass or less, more preferably 40 parts by mass or more and 65 parts by mass or less, and even more preferably 40 parts by mass or more and 63 parts by mass or less, per 100 parts by mass of the total of components (A) to (C).

[0091] The content of component (B) is in the range of 14 parts by mass or more and 60 parts by mass or less per 100 parts by mass of the total of components (A) to (C). When the content of component (B) is 14 parts by mass or more, the extrusion moldability is excellent and it is easy to mold. Furthermore, when the content of component (B) is 60 parts by mass or less, the resulting molded article has a moderate hardness and excellent high temperature resistance, and the reduction in strength can be suppressed even when the molded article is exposed to a high-temperature environment. From this viewpoint, the content of component (B) is preferably 16 parts by mass or more and 50 parts by mass or less, more preferably 18 parts by mass or more and 45 parts by mass or less, and even more preferably 20 parts by mass or more and 45 parts by mass or less, per 100 parts by mass of the total of components (A) to (C).

[0092] Component (C) is included such that the mass ratio of component (C) to component (B) (component (C) / component (B)) is in the range of 0.25 to 1.00. When component (C) / component (B) is within the above range, the high-temperature resistance of the modified elastomer composition can be improved while maintaining both flexibility and moldability. The mass ratio of component (C) / component (B) is preferably 0.25 or more and less than 1.00, more preferably 0.30 or more and 0.95 or less, even more preferably 0.30 or more and 0.90 or less, and most preferably 0.35 or more and 0.80 or less.

[0093] Specifically, the content of component (C) is preferably in the range of 5 parts by mass or more and 40 parts by mass or less per 100 parts by mass of the total of components (A) to (C). When the content of component (C) is 5 parts by mass or more, the molded article has excellent flexibility and appearance. Furthermore, when the content of component (C) is 40 parts by mass or less, the molded article has excellent high-temperature resistance. From this viewpoint, the content of component (C) is preferably 7 parts by mass or more and 40 parts by mass or less, more preferably 10 parts by mass or more and 40 parts by mass or less, particularly preferably 10 parts by mass or more and 35 parts by mass or less, and most preferably 10 parts by mass or more and 30 parts by mass or less, per 100 parts by mass of the total of components (A) to (C).

[0094] In the present invention, the mass ratio of the content of component (B) to the content of component (A) (component (B) / component (A)) is preferably 0.20 or more and 1.20 or less, more preferably 0.25 or more and 1.10 or less, even more preferably 0.30 or more and 1.00 or less, and particularly preferably 0.40 or more and 0.80 or less, from the viewpoint of high temperature resistance, flexibility and moldability. Furthermore, the mass ratio of the content of component (C) to the content of component (A) (component (C) / component (A)) is preferably 0.08 or more and 0.60 or less, more preferably 0.15 or more and 0.50 or less, and even more preferably 0.20 or more and 0.45 or less, from the viewpoint of high temperature resistance and moldability.

[0095] The content of component (D) is preferably 0.01 parts by mass or more and 10 parts by mass or less per 100 parts by mass of the total of components (A), component (B), component (C), and component (F) used as needed. From the viewpoint of ensuring that the crosslinking reaction proceeds sufficiently, it is more preferably 0.05 parts by mass or more and 5 parts by mass or less, and even more preferably 0.1 parts by mass or more and 4 parts by mass or less.

[0096] The content of component (E) is preferably 0.01 parts by mass or more and 3 parts by mass or less per 100 parts by mass of the total of components (A), (B), (C), and component (F) used as needed. From the viewpoint of obtaining a sufficient crosslinking reaction and maintaining a good molded appearance, it is more preferably 0.03 parts by mass or more and 2 parts by mass or less, and even more preferably 0.05 parts by mass or more and 1 part by mass or less.

[0097] When the modified elastomer composition of the present invention contains component (F), the content of component (F) is preferably 1 part by mass or more and 200 parts by mass or less per 100 parts by mass of the total of components (A) and (B). If the content of component (F) is above the lower limit, the effect of improving flexibility due to component (F) can be sufficiently obtained, and if it is below the upper limit, bleed-out from the surface can be suppressed. From this viewpoint, the content of component (F) per 100 parts by mass of the total of components (A) and (B) is more preferably 1 part by mass or more and 15 parts by mass or less, and even more preferably 1 part by mass or more and 10 parts by mass or less.

[0098] When the silanol catalyst component (G) is incorporated into the modified elastomer composition of the present invention, the amount of the catalyst is not particularly limited, but it is preferably 0.0001 parts by mass or more and 0.01 parts by mass or less, and more preferably 0.0001 parts by mass or more and 0.005 parts by mass or less, per 100 parts by mass of the modified elastomer composition excluding component (G). It is preferable that the amount of the silanol catalyst is above the lower limit above because the crosslinking reaction proceeds sufficiently and it is easier to obtain a crosslinked elastomer composition with good heat resistance. It is also preferable that the amount is below the upper limit above because premature crosslinking is less likely to occur in the extruder and roughness of the strand surface and product appearance is less likely to occur.

[0099] <Other ingredients> In addition to the above-mentioned components, the modified elastomer composition of the present invention may contain various additives and fillers, resins and elastomers other than components (A), (B), and (C), to the extent that they do not impair the effects of the present invention.

[0100] Examples of additives include antioxidants, heat stabilizers, ultraviolet absorbers, light stabilizers, antistatic agents, crystal nucleating agents, rust inhibitors, viscosity modifiers, foaming agents, lubricants, and pigments. Of these, it is preferable to include antioxidants, particularly phenolic antioxidants, sulfuric antioxidants, or phosphorus-based antioxidants. It is preferable to include the antioxidant in an amount of 0.1 parts by mass or more and 1 part by mass or less per 100 parts by mass of the modified elastomer composition of the present invention.

[0101] Other resins include, for example, polyolefin resins other than components (A) and (B), polyester resins, polycarbonate resins, polymethyl methacrylate resins, rosin and its derivatives, terpene resins and petroleum resins and their derivatives, alkyd resins, alkylphenol resins, terpenephenol resins, coumarone indene resins, synthetic terpene resins, alkylene resins, polyamide-polyol copolymers and other polyamide elastomers; polyvinyl chloride elastomers and polybutadiene elastomers; styrene elastomers other than component (C); hydrogenated versions thereof; modified versions with acid anhydrides, etc., to introduce polar functional groups; and further, versions obtained by grafting, randomly and / or block copolymerizing other monomers.

[0102] <Manufacturing and molding of modified elastomer compositions> The modified elastomer composition of the present invention can be manufactured by mechanically mixing components (A), (B), and (C) with the unsaturated silane compound of component (D) and the peroxide of component (E), and optionally further with component (F) and other components mentioned above, using a known method, such as a Henschel mixer, V-blender, or tumbler blender, and then mechanically melt-kneading them using a known method. For this melt-kneading, a general melt-kneader such as a Banbury mixer, various kneaders, or a single-screw or twin-screw extruder can be used. Furthermore, as shown in the examples below, when manufacturing the composition of the present invention by kneading with a single-screw or twin-screw extruder, melt-kneading can usually be performed at a heated temperature of 120°C to 240°C, preferably 120°C to 220°C.

[0103] In the modified elastomer composition of the present invention, a crosslinked elastomer composition containing the aforementioned silanol catalyst (component (G)) can be obtained, and after molding it by various molding methods such as extrusion molding, injection molding, and press molding, the crosslinking reaction between silanol groups can be promoted by exposing it to a water atmosphere to obtain a molded article made of the crosslinked elastomer composition. Various conditions can be used for the method of exposure to a water atmosphere, including leaving it in air containing moisture, blowing air containing water vapor, immersing it in a water bath, and spraying warm water in a mist.

[0104] The rate of the crosslinking reaction depends on the conditions under which the material is exposed to a water atmosphere, but typically, exposure should be within a temperature range of 0°C to 130°C and for a period of 5 minutes to 1 week. Particularly preferred conditions are a temperature range of 40°C to 90°C and an exposure period of 30 minutes to 24 hours. When using air containing moisture, the relative humidity should be selected from a range of 1% to 100%.

[0105] The degree of crosslinking of the crosslinked elastomer composition of the present invention obtained in this manner can be adjusted by changing the type and amount of silanol catalyst, the conditions for crosslinking (temperature, time), etc.

[0106] <Duro A hardness> The crosslinked elastomer composition of the present invention preferably has a Duro-A hardness of 75 or higher, as measured in accordance with JIS K6253 (2012) (Duro-A). A Duro-A hardness of 75 or higher provides excellent high-temperature resistance. The Duro-A hardness of the crosslinked elastomer composition is more preferably 80 or higher, even more preferably 85 or higher, and from the viewpoint of flexibility, preferably 98 or lower, more preferably 95 or lower, and even more preferably 93 or lower.

[0107] <Application> The applications of the modified elastomer composition and crosslinked elastomer composition of the present invention are not particularly limited, but they can be suitably used as automotive parts such as rubber hoses, glass run channels, weatherstrips, weather seals, and cushion pads; building and industrial parts such as packings, gaskets, cushions, vibration-damping rubber, and tubes; and other sports and general merchandise, medical parts, food parts, home appliance parts, and wire coatings. In particular, the modified elastomer composition of the present invention has excellent high-temperature resistance and can be suitably used in components exposed to high-temperature environments. For example, it is suitable for building and industrial parts such as automotive parts and building materials, and is especially suitable for automotive hoses and building material tubes that may be used in high-temperature environments.

[0108] The modified elastomer composition and crosslinked elastomer composition of the present invention are particularly excellent in terms of extruded appearance, and are therefore preferably applied as extruded articles in these applications, but are not limited to extruded articles in any way. [Examples]

[0109] The specific embodiments of the present invention will be described in more detail below using examples, but the present invention is not limited to the following examples as long as it does not exceed its gist. 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.

[0110] In the following examples and comparative examples, the raw materials used to prepare the modified elastomer compositions and the evaluation methods for the obtained modified elastomer compositions are as follows.

[0111] [raw materials] The raw materials used in the following examples and comparative examples are as follows:

[0112] <Component (A): Ethylene-α-olefin copolymer rubber> (A1): ENGAGE (registered trademark) XLT8677 (manufactured by Dow Chemical Company) Ethylene-α-olefin copolymer rubber α-olefin:1-octene Density: 0.870g / cm 3 Melting point: 123℃ MFR: 0.5g / 10min (190℃, 21.2N load) (A2): ENGAGE (registered trademark) 8842 (manufactured by Dow Chemical Company) Ethylene-α-olefin copolymer rubber α-olefin:1-octene Density: 0.858g / cm 3 MFR: 1g / 10 minutes (190℃, 21.2N load)

[0113] <Component (B) Propylene resin> (B1): Novatec® PP FY6 (manufactured by Nippon Polypropylene Co., Ltd.) Propylene unit content: 100% by mass MFR: 2.4g / 10min (230℃, 21.2N load) (B2): Novatec® PP EA9HD (manufactured by Nippon Polypropylene Co., Ltd.) Propylene unit content: 100% by mass MFR: 0.4g / 10min (230℃, 21.2N load)

[0114] <Component (C) Styrene-conjugated diene block copolymer and / or hydrogenated thereof> (C1): Asaprene (registered trademark) T-411G (A75) (manufactured by Asahi Kasei Corporation) Styrene-butadiene-styrene block copolymer MFR: 0g / 10 min (200℃, 49N load) Density: 0.94g / cm 3 Styrene block content: 30% by mass (C2): TAIPOL6159 (manufactured by TSRC) Styrene-ethylene-butylene-styrene copolymer (SEBS) MFR: 0g / 10 min (200℃, 49N load) Density: 0.94g / cm 3 Styrene block content: 30% by mass 1,2-bond ratio of the butadiene portion: 30% by mass 1,4-bonding ratio of the butadiene portion: 70% by mass (C3): Septon (registered trademark) 4077 (manufactured by Kuraray Co., Ltd.) Styrene-ethylene-ethylene-propylene-styrene copolymer (SEEPS) MFR: 0g / 10 min (200℃, 49N load) Density: 0.94g / cm 3 Styrene block content: 30% by mass

[0115] <Component (D) Unsaturated silane compound> (D1): KBM-1003 (manufactured by Shin-Etsu Chemical Co., Ltd.) Vinyltrimethoxysilane

[0116] <Component (E) Peroxide> (E1): Trigonox 101-40C (manufactured by Nuurion Pharmaceuticals) A mixture of 40% by mass of 2,5-dimethyl-2,5-di(t-butylperoxy)hexane and 60% by mass of organic filler.

[0117] <Component (F): Hydrocarbon-based rubber softener> (F1): Diana® Process Oil PW90 (manufactured by Idemitsu Kosan Co., Ltd.) Paraffin-based oils Kinematic viscosity at 40°C: 95.54 cSt Pour point: -15℃ Flash point: 272℃

[0118] <Other resins> • Novatec® PP HG30U (manufactured by Nippon Polypropylene Co., Ltd.) Polypropylene resin with short glass fibers MFR: 10g / 10 minutes (230℃, 21.2N load) Glass fiber weight ratio: 30% by weight Fiber length: 1 mm or less

[0119] <Crosslinking agent> • Divinylbenzene (manufactured by Wako Pure Chemical Industries, Ltd., a mixture of 55% by mass of divinylbenzene and 45% by mass of ethylbenzene)

[0120] [Evaluation Method] <End point of melting of component (A)> Using a differential scanning calorimeter (DSC6220) manufactured by Hitachi High-Tech Science Corporation, approximately 5 mg of the sample was heated from 20°C to 200°C at a heating rate of 100°C / min in accordance with JIS K7121 (2012). After holding at 200°C for 3 minutes, the temperature was lowered to -10°C at a cooling rate of 10°C / min. Subsequently, the temperature was raised to 200°C at a heating rate of 10°C / min. The extrapolation peak termination point (°C) was calculated from the thermogram measured at this point and defined as the melting termination point.

[0121] <Evaluation of Modified Elastomer Compositions / Crosslinked Elastomer Compositions> (1) Extrusion moldability (spreadability) The modified elastomer composition was placed in a melt extruder (Capillograph, manufactured by Toyo Seiki Co., Ltd.) set to a heating temperature of 210°C. The take-up speed of the extruded strands, which were initially 10 mm / min, was gradually increased, and the take-up speed at which the strands broke was measured. Measurement conditions: Orephis aperture: 2.095 mm, length: 8 mm, acceleration at take-up speed: 2 m / min 2 That's what I decided.

[0122] (2) Tensile properties For the evaluation extruded belt, the fracture stress, 100% modulus, and fracture elongation were measured at 23°C and 80°C in accordance with the JIS K6251 (2017) standard, using a dumbbell-shaped No. 3 belt at a test speed of 500 mm / min.

[0123] (3) Relaxation of tensile stress For the evaluation of the extruded belts, in accordance with the JIS K6251 (2017) standard, a dumbbell-shaped No. 3 belt was stretched at a speed of 100 mm / min at 80°C until it reached 100% elongation between the gauge marks, and held in that state for 10 minutes. The maximum and minimum points of the test force and stress were determined, and the stress (test force) retention rate at the minimum point was calculated. The maximum point was the test force immediately after reaching 100% elongation, and the minimum point was the value measured 10 minutes after reaching 100% elongation.

[0124] (4) Duro A hardness For the evaluation extruded belts, the Duro-A hardness of the cross-linked elastomer composition was measured in accordance with JIS K6253 (2012) (Duro-A). The value was taken 15 seconds after the hardness tester needle touched the test piece.

[0125] (Example 1) According to the composition shown in Table 1, 61 parts by mass of component (A), 25 parts by mass of component (B), 14 parts by mass of component (C), 1.92 parts by mass of component (D), 0.20 parts by mass of component (E), and 0.015 parts by mass of crosslinking aid were weighed out and mixed in a Henschel mixer for 1 minute. Next, the obtained mixture was fed into the upstream feed port of a co-screw extruder (manufactured by Japan Steel Works, Ltd., product number: TEX30, L / D=46, number of cylinder blocks: 12) using a mass feeder. With a total discharge rate of 25 kg / h, the mixture was melt-kneaded by raising the temperature from the upstream to the downstream section in the range of 120 to 200°C, and pelletized to produce a modified elastomer composition. To 100 parts by mass of the obtained modified elastomer composition, 4 parts by mass of Mitsubishi Chemical's "LZ033" (product name) as component (G) silanol catalyst (0.0048 parts by mass as tin catalyst) were added. This was then extruded into an extruded belt using a single-screw extruder (IKG Corporation, product number PMS40-28, Φ40mm, L / D=28) with a die shape of 25mm x 3mm, by drawing down to a thickness of 2mm. This was then exposed to a constant temperature and humidity chamber at 85°C and 85%RH for 24 hours to obtain the evaluation sample.

[0126] Table 1 shows the results of evaluations performed using an evaluation extrusion belt made of the modified elastomer composition and the crosslinked elastomer composition of Example 1.

[0127] (Examples 2-7, Comparative Examples 1-4) Except for changing the raw material formulations shown in Table 1, the modified elastomer compositions and evaluation extrusion belts for Examples 2-7 and Comparative Examples 1-4 were obtained in the same manner as in Example 1, and were evaluated in the same manner. The results are shown in Table 1.

[0128] [Table 1]

[0129] [Evaluation Results] As shown in Table 1, Examples 1 to 7, which correspond to the modified elastomer composition and crosslinked elastomer composition of the present invention, exhibited excellent flexibility, with a ductility of 9.4 m / min or more when the modified elastomer composition was extruded. Furthermore, Examples 1 to 7 also exhibited excellent high-temperature resistance, with a breaking point stress of 7.3 MPa or more at 80°C for the evaluation extruded belt. In contrast, Comparative Example 1 had insufficient high-temperature resistance due to an excessive amount of component (A), Comparative Example 2 lacked flexibility due to the absence of component (C), and Comparative Examples 3 and 4 lacked both flexibility and high-temperature resistance because they did not contain component (C) and had an excessive amount of component (A).

Claims

1. A modified elastomer composition comprising the following components (A) to (D) and grafted with the following component (E), A modified elastomer composition in which, when the total amount of components (A) to (C) is 100 parts by mass, component (A) is 30 parts by mass or more and 75 parts by mass or less, component (B) is 14 parts by mass or more and 60 parts by mass or less, and the mass ratio of the content of component (C) to the content of component (B) (component (C) / component (B)) is 0.25 or more and 1.00 or less. Component (A): Ethylene-α-olefin copolymer rubber Component (B): Propylene resin Component (C): At least one of a styrene-conjugated diene block copolymer and a hydrogenated styrene-conjugated diene block copolymer. Component (D): Unsaturated silane compound Ingredient (E): Peroxide

2. The modified elastomer composition according to claim 1, wherein when the total of components (A) to (C) is 100 parts by mass, it contains 5 parts by mass or more and 40 parts by mass or less of component (C).

3. The modified elastomer composition according to claim 1, wherein the component (C) is a styrene-conjugated diene block copolymer.

4. The modified elastomer composition according to claim 1, wherein the melting end peak temperature of component (A), as measured by differential scanning calorimeter (DSC), is 115°C or higher.

5. The modified elastomer composition according to claim 1, wherein the component (D) is a compound represented by the following formula (1). RSi(R') ３ ・・・(1) (In formula (1), R is an ethylenically unsaturated hydrocarbon group, and R' are each independently a hydrocarbon group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms, and at least one of R' is an alkoxy group having 1 to 10 carbon atoms.)

6. The modified elastomer composition according to claim 1, further comprising component (F): a hydrocarbon-based rubber softener in an amount of 1 to 200 parts by mass per 100 parts by mass of the total of components (A) and (B).

7. A crosslinked elastomer composition comprising a modified elastomer composition according to any one of claims 1 to 6, wherein the modified elastomer composition is crosslinked with component (G): silanol catalyst.

8. The crosslinked elastomer composition according to claim 7, wherein the Duro-A hardness according to JIS K6253 (2012) (Duro-A) is 75 or higher.

9. A molded article comprising the modified elastomer composition according to any one of claims 1 to 6.

10. The molded body according to claim 9, which is a hose for automotive parts.

11. A molded article comprising the crosslinked elastomer composition described in claim 7.

12. The molded body according to claim 11, which is a hose for automotive parts.

Images