JP2021147416A - Modified elastomer composition, crosslinked elastomer composition, and injection-molded article thereof - Google Patents

Abstract

To provide a modified elastomer composition excellent in compression set, touch feeling, and injection molding appearance.SOLUTION: The modified elastomer composition contains the following components (A)-(C) and is grafted with the following component (D): (A) an ethylene/α-olefin copolymer rubber having a density of 0.875-0.900 g/cm3; (B) a propylene/ethylene random copolymer having an ethylene unit content of 0.1-5.0 mass%; (C) an unsaturated silane compound; and (D) a peroxide.SELECTED DRAWING: None

Description

The present invention relates to a modified elastomer composition, a crosslinked elastomer composition and an injection molded product thereof. More specifically, the present invention relates to a modified elastomer composition and a crosslinked elastomer composition having excellent compression set, tactile sensation, and injection molded appearance, and an injection molded product using the same.

A thermoplastic elastomer is an elastomer that softens by heating and has fluidity, and when cooled, it has rubber elasticity. Thermoplastic elastomers have the same molding processability as thermoplastic resins, have rubber elasticity, and are recyclable. Therefore, automobile parts, building parts, medical parts, electric wire coating materials, miscellaneous goods, etc. It is widely used in various applications.

When used in applications that require sealing properties, it is important to have good rubber elasticity or compression set characteristics, and much research has been done for that purpose. However, since the thermoplastic elastomer contains a thermoplastic resin such as polyolefin in order to ensure the thermoplasticity, the compression set has insufficient compressive permanent strain characteristics as compared with the thermosetting rubber, and the applications that can be used are limited. .. On the other hand, a thermosetting rubber such as EPDM has excellent compression set characteristics, but has a drawback that it requires a long cross-linking step and is inferior in durability.

As a thermoplastic elastomer composition having improved compression set characteristics, for example, ethylene / α-olefin / non-conjugated diene copolymer rubber; ethylene / α-olefin copolymer rubber containing no non-conjugated diene unit; polyethylene, polypropylene Alternatively, a propylene / α-olefin copolymer; a modified elastomer composition obtained by graft-modifying a composition containing an unsaturated silane compound with a peroxide, or a crosslinked elastomer composition obtained by further cross-linking the composition is known. (See Patent Document 1). In Patent Document 1, the modified elastomer composition and the crosslinked elastomer composition achieve both compressive permanent strain characteristics equivalent to those of a thermosetting rubber and simple extrusion moldability similar to that of a thermoplastic elastomer, and compressive permanent strain. It is described that a molded product having an excellent and good extrusion-molded appearance can be obtained.

: Japanese Unexamined Patent Publication No. 2019-131797

However, when the modified elastomer composition and the crosslinked elastomer composition described in Patent Document 1 are used for injection molding, there is a problem that the tactile sensation and the injection molding appearance of the obtained molded product are inferior.

The present invention has been made in view of the above problems, and an object of the present invention is that it exhibits compressive permanent strain characteristics equivalent to those of conventional thermosetting rubbers and has moldability similar to that of thermoplastic resins, and is good. It is an object of the present invention to provide a modified elastomer composition, a crosslinked elastomer composition, and an injection molded product thereof, which can obtain an injection molded product having a tactile sensation and an injection molded appearance.

As a result of diligent studies to solve the above problems, the present inventor contains an ethylene / α-olefin copolymer rubber having a specific density; a specific propylene / ethylene random copolymer; and an unsaturated silane compound. By preparing a modified elastomer composition grafted with a peroxide or a crosslinked elastomer composition obtained by cross-linking the same, the compression permanent strain characteristics equivalent to those of a thermosetting rubber and the convenience similar to those of a thermoplastic resin are obtained. We have found that it is possible to obtain a molded product having both injection moldability, excellent compression-resistant elastomer, good tactile sensation and injection-molded appearance, and completed the present invention.
That is, the gist of the present invention lies in the following [1] to [12].

[1] A modified elastomer composition containing the following components (A) to (C) and grafted with the following components (D).
Component (A): Ethylene / α-olefin copolymer rubber having a density of 0.875 to 0.900 g / cm ³ Component (B): Ethylene with an ethylene unit content of 0.1 to 5.0% by mass. Ethylene random copolymer component (C): unsaturated silane compound component (D): peroxide

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

[3] The modified elastomer composition according to [1] or [2], wherein the component (C) is a compound represented by the following formula (1).
RSi (R') ₃ ... (1)
(However, R is an ethylenically unsaturated hydrocarbon group, and R'is a hydrocarbon group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms independently of each other, and at least one of R'. One is an alkoxy group having 1 to 10 carbon atoms.)

[4] Further, the component (E): a hydrocarbon-based rubber softening agent is contained in an amount of 1 to 200 parts by mass with respect to a total of 100 parts by mass of the component (A) and the component (B) [1] to [ 3] The modified elastomer composition according to any one of.

[5] Further, the component (F): styrene-based block copolymer is contained in an amount of 1 to 100 parts by mass with respect to a total of 100 parts by mass of the component (A) and the component (B) [1] to [4]. ] The modified elastomer composition according to any one of.

[6] Further, the component (G): ethylene / α-olefin / non-conjugated diene copolymer rubber is contained in an amount of 1 to 100 parts by mass with respect to a total of 100 parts by mass of the component (A) and the component (B). , The modified elastomer composition according to any one of [1] to [5].

[7] A crosslinked elastomer composition obtained by cross-linking the modified elastomer composition according to any one of [1] to [6] with a component (H): silanol catalyst.

[8] The crosslinked elastomer composition according to [7], wherein the Duro A hardness in JIS K6253 (2012) (Duro-A) is 30 or more and 90 or less.

[9] An injection-molded article of the modified elastomer composition according to any one of [1] to [6].

[10] An injection-molded article of the crosslinked elastomer composition according to [7] or [8].

[11] A method for producing a modified elastomer composition, which comprises a step of melt-kneading the following components (A) to (D).
Component (A): Ethylene / α-olefin copolymer rubber having a density of 0.875 to 0.900 g / cm ³ Component (B): Ethylene with an ethylene unit content of 0.1 to 5.0% by mass. Ethylene random copolymer component (C): unsaturated silane compound component (D): peroxide

[12] A step of melt-kneading the following components (A) to (D) to obtain a modified elastomer composition.
A step of obtaining an injection molded product by injection molding the modified elastomer composition and the component (H): silanol catalyst.
A method for producing an injection molded product made of a crosslinked elastomer composition, which comprises a step of exposing the injection molded product to a water atmosphere to obtain an injection molded product made of the crosslinked elastomer composition.
Component (A): Ethylene / α-olefin copolymer rubber having a density of 0.875 to 0.900 g / cm ³ Component (B): Ethylene with an ethylene unit content of 0.1 to 5.0% by mass. Ethylene random copolymer component (C): unsaturated silane compound component (D): peroxide

According to the present invention, there are provided a modified elastomer composition and a crosslinked elastomer composition capable of obtaining an injection molded product having excellent compression set characteristics and a good tactile sensation and injection molded appearance, and an injection molded product using the modified elastomer composition and the crosslinked elastomer composition. be able to.
The modified elastomer composition and the crosslinked elastomer composition of the present invention and the injection molded product using the modified elastomer composition are exposed to applications requiring good rubber elasticity, in which thermosetting rubber is conventionally used, and to a harsher usage environment. It can be expected to be applied to various applications.

Hereinafter, embodiments of the present invention will be described in detail, but the present invention is not limited to the following description, and can be arbitrarily modified and carried out without departing from the gist of the present invention. In addition, in this specification, when a numerical value or a physical property value is put before and after using "~", it is used as including the value before and after that.

[Modified Elastomer Composition]
The modified elastomer composition of the present invention is a modified elastomer composition containing the following components (A) to (C) and grafted with the following components (D), and more preferably the following components (E) and components ( F) and component (G) are included.
Component (A): Ethylene / α-olefin copolymer rubber component (B) with a density of 0.875 to 0.900 g / cm ³ : Ethylene with an ethylene unit content of 0.1 to 5.0% by mass. Ethylene random copolymer component (C): unsaturated silane compound component (D): peroxide component (E): hydrocarbon-based rubber softener component (F): styrene-based block copolymer component (G): Ethylene / propylene / non-conjugated diene copolymer

<Mechanism>
The mechanism by which the modified elastomer composition of the present invention can obtain an injection-molded product having excellent compression set characteristics and a good tactile sensation and injection-molded appearance is presumed as follows.
Since the component (A) is grafted by the components (C) and (D) and high rubber elasticity can be obtained, the compression set is excellent. Further, by using the component (A), the amorphous component in the rubber is suppressed, so that a molded product having a good tactile sensation with less stickiness can be obtained. Further, by using the component (B), an injection-molded article having a good appearance with few flow marks can be obtained.

<Component (A): Ethylene / α-olefin copolymer rubber having a density of 0.875 to 0.900 g / cm ^3>
The component (A) is an ethylene / α-olefin copolymer rubber having a density of 0.875 to 0.900 g / cm ^3. The ethylene / α-olefin copolymer rubber of the component (A) is distinguished from the component (G) described later in that it is a copolymer rubber containing no non-conjugated diene unit. The ethylene / α-olefin copolymer rubber of the component (A) is a polymer containing the largest amount of ethylene units among its constituent units, and a known ethylene / α-olefin copolymer rubber is appropriately used. The ethylene unit content of the ethylene / α-olefin copolymer rubber is preferably 60 to 99% by mass, more preferably 60 to 85% by mass. When the content of ethylene units is within the above range, a modified elastomer composition having excellent mechanical strength and rubber elasticity tends to be easily obtained.

The density of the ethylene / α-olefin copolymer rubber of the component (A) used in the present invention (measured by JIS K6922-1, 2: 1997) was 0.875 to 0.900 g / cm ³ , and 0. it is preferably 876~0.895g / cm ^3, more preferably 0.877~0.890g / cm ^3. When the density is not more than the above upper limit value, it tends to be flexible and excellent in compression resistance permanent strain.
The lower limit of the density of the ethylene / α-olefin copolymer rubber of the component (A) used in the present invention is as follows.
That is, when the present inventor observed an injection molded product of the modified elastomer composition of the present invention containing the components (A) to (C) and grafted with the component (D) with an electron microscope, the components ( It was found that A) is distributed on the surface of the injection molded product, and this component (A) has a great influence on the stickiness. The stickiness derived from the component (A) can be improved by suppressing the amorphous component of the component (A), that is, by controlling the density. Specifically, by setting the density to the above lower limit value or more, the stickiness of the injection molded product can be suppressed and the tactile sensation can be improved.

Specific examples of the ethylene / α-olefin copolymer rubber used in the present invention include ethylene / propylene copolymer, ethylene / 1-butene copolymer, ethylene / 4-methyl-1-pentene copolymer, and the like. Examples thereof include copolymer rubber of ethylene such as ethylene / 1-hexene copolymer and ethylene / 1-octene copolymer and one or more kinds of α-olefin having 3 to 10 carbon atoms.

The type of catalyst used in producing the ethylene / α-olefin copolymer rubber is not particularly limited, and examples thereof include a Ziegler-Natta catalyst and a metallocene catalyst. Among these, an ethylene / α-olefin copolymer rubber produced by a metallocene catalyst is preferable.

The ethylene / α-olefin copolymer rubber used in the present invention has a melting end peak temperature (hereinafter sometimes referred to as “melting end point”) measured by a differential scanning calorimeter (DSC) of 115 ° C. or higher. Those are preferable. When the melting end point of the ethylene / α-olefin copolymer rubber is 115 ° C. or higher, the shape can be maintained by crystals even at a high temperature, so that the compression set has good permanent strain characteristics. From this viewpoint, the melting end point of the ethylene / α-olefin copolymer rubber is preferably 115 ° C. or higher, particularly preferably 117 ° C. or higher. However, if the melting end point of the ethylene / α-olefin copolymer rubber is excessively high, there is a risk that the appearance will be poor due to unmelted lumps at the time of molding temperature rise and early crystallization (melt fracture) at the time of molding cooling. Therefore, the melting end point of the ethylene / α-olefin copolymer rubber is usually 145 ° C. or lower. The melting end point of the ethylene / α-olefin copolymer rubber is measured by the method described in the section of Examples described later.

The content of each structural unit of the component (A) can be determined by infrared spectroscopy and NMR. The content of each of the constituent units of the component (B) and the component (G), which will be described later, can be determined by infrared spectroscopy.

The melt flow rate (MFR) of the ethylene / α-olefin copolymer rubber used in the present invention is measured in accordance with JIS K7210 (2014) at a temperature of 190 ° C. and a load of 21.2 N. ), Preferably 0.01 to 30 g / 10 minutes. By setting the upper limit of the MFR of the ethylene / α-olefin copolymer rubber used in the present invention to 30 g / 10 minutes or less, it is possible to suppress the compression set from becoming too large and maintain good sealing properties. Further, by setting the lower limit of MFR to 0.01 g / 10 minutes or more, it is possible to suppress deterioration of productivity due to an increase in resin pressure when the modified elastomer composition of the present invention is produced by melt extrusion. From these viewpoints, the MFR of the ethylene / α-olefin copolymer rubber is more preferably 0.1 g / 10 minutes or more, and more preferably 20 g / 10 minutes or less.

The ethylene / α-olefin copolymer rubber used in the present invention can be obtained as a commercially available product. For example, Dow Chemicals Engage (registered trademark) series, Nippon Polyethylene Kernel (registered trademark) series, Dow Chemicals Infuse (trademark registered) series, Mitsui Chemicals Toughmer (registered trademark) Applicable products can be selected and used from the registered trademark) series and the Evolu (registered trademark) series manufactured by Mitsui Chemicals.

As the ethylene / α-olefin copolymer rubber of the component (A), only one type can be used alone, or two or more types can be used in any combination and ratio.

<Component (B): Propylene / ethylene random copolymer having an ethylene unit content of 0.1 to 5.0% by mass>
The component (B) used in the present invention is a propylene / ethylene random copolymer having an ethylene unit content of 0.1 to 5.0% by mass. Component (B) contributes to the appearance of injection molding. When the ethylene unit content of the component (B) is equal to or higher than the above lower limit value, it is easy to have crystallinity suitable for controlling the material solidification rate during injection molding, the generation of flow marks can be suppressed, and the appearance of injection molding can be improved. Can be done well. On the other hand, by setting the ethylene unit content of the component (B) to the above upper limit or less, the crystallinity does not become too low, the deformation of the molded product can be suppressed during the production of the injection molded product, and at the same time, the heat resistance of the molded product is improved. There is a tendency to be able to. The content of the ethylene unit of the propylene / ethylene random copolymer of the component (B) is preferably less than 5.0% by mass, and more preferably 1.0 to 4.0% by mass.

The content of the propylene unit of the propylene / ethylene random copolymer of the component (B) used in the present invention is preferably more than 95.0% by mass and 99.9% by mass or less, more preferably 96.0 to 96.0%. It is 99.0% by mass.

The melt flow rate (MFR) of the propylene / ethylene random copolymer of the component (B) is measured by JIS K 7210 (2014) at 230 ° C. and a load of 21.2 N, and is usually 0.01 g / 10 minutes or more. From the viewpoint of fluidity, it is preferably 1 g / 10 minutes or more, more preferably 5 g / 10 minutes or more, and further preferably 10 g / 10 minutes or more. On the other hand, it is usually 200 g / 10 minutes or less, preferably 150 g / 10 minutes or less, more preferably 100 g / 10 minutes or less, still more preferably 70 g / 10 minutes or less from the viewpoint of moldability.

As a method for producing the propylene / ethylene random copolymer of the component (B), a known polymerization method using a known catalyst for olefin polymerization is used. For example, a multi-stage polymerization method using a Ziegler-Natta catalyst can be mentioned. For this multi-stage polymerization method, a slurry polymerization method, a solution polymerization method, a massive polymerization method, a gas phase polymerization method and the like can be used, and two or more of these may be combined for production.

The propylene / ethylene random copolymer of component (B) can be obtained as a commercially available product. For example, Prime Polypro (registered trademark) manufactured by Prime Polymer Co., Ltd., Sumitomo Noblen (registered trademark) manufactured by Sumitomo Chemical Co., Ltd., propylene / ethylene random copolymer manufactured by Sun Aroma, Novatec (registered trademark) PP manufactured by Nippon Polypro Co., Ltd. Trademark), Adflex (registered trademark), Fluorex (registered trademark), Fluorex (registered trademark), ExxonMobile PP manufactured by ExxonMobile, Formorene (registered trademark) manufactured by Formosa Plastics, Borelialis PP manufactured by Borealis, Borealis PP manufactured by Borealis A. Schulman Inc. ASI POLYPROPYLENE, INEOS Olefins & Polymers, Inc. INEOS PP, Braskem Inc. Braskem PP, SAMSUNG TOTAL PETROCHEMICALS Co. Sumsung Total, Sabic manufactured by Sabic (registered trademark) PP, TOTAL PETROCHEMICALS Co., Ltd. TOTAL PETROCHEMICALS Polypropylene, SK Corp. YUPLENE ( Applicable products can be selected and used from (registered trademarks).

As the propylene / ethylene random copolymer of the component (B), only one type can be used alone, or two or more types can be used in any combination and ratio.

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

In the above formula (1), R is an ethylenically unsaturated hydrocarbon group, and R'is a hydrocarbon group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms independently of each other. At least one of them is an alkoxy group having 1 to 10 carbon atoms.

In the 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. Specific examples thereof include alkenyl groups such as vinyl group, propenyl group, butenyl group and cyclohexenyl group.

In the 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 1 to 4 carbon atoms. It is an alkoxy group of. Further, 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 having 1 to 10 carbon atoms of R'may be any of an aliphatic group, an alicyclic group, and an aromatic group, but it is preferably an aliphatic group. The alkoxy group having 1 to 10 carbon atoms of R'may be linear, branched or cyclic, but is preferably linear or branched. When R'is a hydrocarbon group, specifically, an alkyl group represented by a methyl group, an ethyl group, an isopropyl group, a t-butyl group, an n-butyl group, an i-butyl group, a cyclohexyl group, or a phenyl group. Examples thereof include an aryl group typified by a group. When R'is an alkoxy group, specific examples thereof include a methoxy group, an ethoxy group, an isopropoxy group and a β-methoxyethoxy group.

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

As the unsaturated silane compound, vinyl trialkoxysilane represented by vinyltrimethoxysilane, vinyltriethoxysilane, propenyltrimethoxysilane and the like is desirable among those represented by the formula (1). This is because the vinyl group enables the modification of the component (A) to an ethylene / α-olefin copolymer rubber, and the alkoxysilyl group promotes the cross-linking reaction described later. That is, the alkoxysilyl group introduced by graft-modifying the ethylene / α-olefin copolymer rubber with an unsaturated silane compound reacts with water and hydrolyzes in the presence of the silanol catalyst of the component (H) to hydrolyze the silanol. By forming groups and dehydrating and condensing silanol groups, ethylene / α-olefin copolymer rubbers are bonded to each other and a cross-linking reaction occurs. As these unsaturated silane compounds, one type may be used alone, or two or more types may be used in combination.

<Component (D): Peroxide>
Examples of the peroxide of the component (D) include hydroperoxides, dialkyl peroxides, diacyl peroxides, peroxyesters, and organic peroxides contained in the ketone peroxide group. Specific examples thereof include the following. Something can be mentioned.

The hydroperoxide group includes cumene hydroperoxide, t-butyl hydroperoxide, etc., and the dialkyl peroxide group includes dicumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5. Includes −di (t-butylperoxy) hexane, 2,5-dimethyl-2,5-di (t-butylperoxyl) -3-hexine, di (2-t-butylperoxyisopropyl) benzene, etc. , The diacyl peroxide group includes lauryl peroxide, benzoyl peroxide and the like. The peroxyester group includes t-butylperoxyacetate, t-butylperoxybenzoate, t-butylperoxyisopropylcarbonate and the like, and the ketone peroxide group includes cyclohexanone peroxide and the like.

Of these, a radical generator having a high thermal decomposition temperature is preferable from the viewpoint of a graft reaction in a melt-kneading process by an extruder when producing the modified elastomer composition of the present invention. From this point of view, di-t-butyl peroxide, di (2-t-butylperoxyisopropyl) benzene, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, and dicumyl peroxide are preferable. ..

As the peroxide of the component (D), only one type can be used alone, or two or more types can be used in any combination and ratio.

<Component (E): Hydrocarbon-based rubber softener>
The modified elastomer composition of the present invention can contain a hydrocarbon-based rubber softener as a component (E) from the viewpoint of increasing flexibility and improving processability, fluidity, and oil resistance.

Examples of the softening agent for hydrocarbon-based rubber of the component (E) include a softening agent for mineral oil-based rubber and a softening agent for synthetic resin-based rubber. Among these, from the viewpoint of affinity with other components and the like. , A softening agent for mineral oil-based rubber is preferable.

The softener for mineral oil-based rubber is generally a mixture of aromatic hydrocarbons, naphthenic hydrocarbons and paraffinic hydrocarbons, and the ratio of carbon of the paraffinic hydrocarbon to the total carbon atom is 50% or more. Those with a carbon content of 30 to 45% are called paraffin oils, those with a carbon content of naphthenic hydrocarbons of 30 to 45% are called naphthenic oils, and those with a carbon content of aromatic hydrocarbons of 35% or more are called aromatic oils. ing. Among these, a liquid hydrocarbon softener that is liquid at room temperature (23 ± 2 ° C.) is preferable, and a liquid paraffin oil that is liquid at room temperature is more preferable.
By using a liquid hydrocarbon-based rubber softener as the hydrocarbon-based rubber softener, the flexibility and elasticity of the modified elastomer composition of the present invention can be increased, and the processability and fluidity can be dramatically improved. It tends to improve.

The paraffin-based oil is not particularly limited, but one having a kinematic viscosity at 40 ° C. of usually 10 cSt (centistokes) or more, preferably 20 cSt or more, and usually 800 cSt or less, preferably 600 cSt or less is preferably used. The pour point is usually −40 ° C. or higher, preferably −30 ° C. or higher, and 0 ° C. or lower is preferably used. Further, a flash point (COC) of usually 200 ° C. or higher, preferably 250 ° C. or higher, and usually 400 ° C. or lower, preferably 350 ° C. or lower is preferably used.

As the hydrocarbon-based rubber softener of the component (E), only one type can be used alone, or two or more types can be used in any combination and ratio.

<Component (F): Styrene-based block copolymer>
It is preferable that the modified elastomer composition of the present invention further contains the styrene-based block copolymer of the component (F). By containing the styrene-based block copolymer of the component (F), the effects of further permanent reduction in compression and improvement in tactile sensation can be obtained.

The styrene-based block copolymer of the component (F) used in the present invention has at least two polymer blocks P derived from a vinyl aromatic compound and at least one polymer block Q derived from a conjugated diene. It is preferably a block copolymer and at least one block copolymer in the group consisting of a block copolymer and a hydrogenated block copolymer obtained by hydrogenating the block copolymer.

In the component (F), the monomeric vinyl aromatic compound constituting the block P is not particularly limited, but a styrene derivative such as styrene or α-methylstyrene is preferable. Above all, it is preferable to mainly use styrene. Here, "mainly" in the component (F) means that the content of the constituent unit in the block is 50% by mass or more. The block P may contain a monomer other than the vinyl aromatic compound as a raw material.

Examples of the monomer other than the vinyl aromatic compound include ethylene and α-olefin. When the block P contains a monomer other than the vinyl aromatic compound as a raw material, the content thereof is 50% by mass or less, preferably 40% by mass or less. When the content of the monomer other than the vinyl aromatic compound is in this range, the heat resistance and the compression set tend to be good.

The conjugated diene of the monomer constituting the block Q is not particularly limited, but it is preferably mainly composed of butadiene and / or isoprene, and more preferably mainly composed of butadiene. The block Q may contain a monomer other than the conjugated diene as a raw material.

Examples of the monomer other than the conjugated diene include isobutylene and styrene. When the block Q contains a monomer other than the conjugated diene as a raw material, the content thereof is 50% by mass or less, preferably 40% by mass or less. Bleedout tends to be suppressed when the content of the monomer other than the conjugated diene is in this range.

The styrene-based block copolymer of the component (F) is a hydrogenated block obtained by hydrogenating a block copolymer having at least two of the above-mentioned polymer blocks P and at least one of the above-mentioned polymer blocks Q. It may be a polymer. More specifically, it may be a hydrogenated block copolymer in which the double bond of the block Q of the block copolymer is hydrogenated. The hydrogenation rate of the block Q is not particularly limited, but is preferably 80 to 100% by mass, more preferably 90 to 100% by mass.

The component (F) in the present invention preferably has a structure having at least two polymer blocks P and at least one polymer block Q, and may be linear, branched, radial or the like. Is preferably a block copolymer represented by the following formula (2) or (3).

P- (QP) _m (2)
(PQ) _n (3)
(In the formula, P represents the polymer block P, Q represents the polymer block Q, m represents an integer of 1 to 5, and n represents an integer of 2 to 5.)

In the formula (2) or (3), m and n should be larger in terms of lowering the order-disorder transition temperature as a rubber polymer, but smaller in terms of ease of manufacture and cost. good.

The mass ratio of the block P and the block Q constituting the component (F) is arbitrary, but from the viewpoint of good tactile sensation of the modified elastomer composition of the present invention, it is preferable to have a large amount of the block P, while flexibility. It is preferable that the block P is small from the viewpoint of bleed-out suppression and compression resistance permanent strain.

The mass ratio of the block P in the component (F) is preferably 10% by mass or more, more preferably 15% by mass or more, still more preferably 20% by mass or more, and preferably 60% by mass or less, more preferably. It is 50% by mass or less, more preferably 45% by mass or less.

The styrene-based block copolymer of the component (F) used in the present invention is a melt flow rate (MFR) measured under the conditions of a temperature of 190 ° C. and a load of 21.2 N in accordance with JIS K7210 (2014), preferably. It is 10 g / 10 minutes or less. By setting the upper limit of the MFR of the component (F) used in the present invention to 10 g / 10 minutes or less, it is possible to suppress the compression set from becoming too large and maintain good sealing performance. The MFR is more preferably 5 g / 10 minutes or less, and even more preferably 1 g / 10 minutes or less. The MFR of the styrene-based block copolymer of the component (F) used in the present invention may be 0 g / 10 minutes.

The density of the styrene-based block copolymer of the component (F) used in the present invention (measured by JIS K6922-1, 2: 1997) is usually 0.88 to 1.00 g / cm ³ , and 0.89 to 0.89. is preferably 0.98 g / cm ^3, more preferably 0.89~0.96g / cm ^3. When the density is not more than the above upper limit value, it tends to be flexible and excellent in compression resistance permanent strain. When the density is equal to or higher than the above lower limit value, the heat resistance tends to be excellent.

The method for producing the component (F) in the present invention may be any method as long as the above-mentioned structure and physical properties can be obtained, and is not particularly limited. For example, it can be obtained by performing block polymerization in an inert solvent using a lithium catalyst or the like by the method described in Japanese Patent Publication No. 40-23798. Further, hydrogenation (hydrogenation) of block copolymers is performed, for example, in JP-A-42-8704, JP-A-43-6636, JP-A-59-133203 and JP-A-60-79005. Etc. can be carried out in the presence of a hydrogenation catalyst in an inert solvent.

The styrene-based block copolymer of the component (F) used in the present invention includes a styrene / butadiene / styrene block copolymer and its hydrogenated product, a styrene / isoprene / butadiene / styrene block copolymer and its hydrogenated product, and the like. Among these, styrene / butadiene / styrene block copolymers are preferable.

Ingredient (F) can be obtained as a commercial product. As hydrogenated styrene block copolymers, Kraton Polymer's "KRATON (registered trademark) -G series", Kuraray's "Septon (registered trademark) series", "Hybler (registered trademark) series", and Asahi Kasei Examples include the "Tough Tech (registered trademark) series" manufactured by the company. As non-hydrogenated styrene block copolymers, Kraton Polymer's "KRATON (registered trademark) -D series", Kuraray's "Hybler (registered trademark) series", and Asahi Kasei's "Toughprene (registered)" Trademark) ”,“ Asaprene (registered trademark) series ”and the like.

As the component (F), only one type may be used, or two or more types having different block compositions, physical properties, etc. may be mixed and used.

<Component (G): Ethylene / α-olefin / non-conjugated diene copolymer rubber>
The modified elastomer composition of the present invention may contain ethylene / α-olefin / non-conjugated diene copolymer rubber as a component (G), and may contain ethylene / α-olefin / non-conjugated diene copolymer rubber. As a result, the compression set characteristics can be more effectively improved by cross-linking the ethylene / α-olefin / non-conjugated diene copolymer rubber.

The ethylene / α-olefin / non-conjugated diene copolymer rubber of the component (G) is a copolymer rubber containing ethylene, an α-olefin, and a non-conjugated diene compound as copolymerization components. The ethylene / α-olefin / non-conjugated diene copolymer rubber is a mixture of ethylene / α-olefin / non-conjugated diene copolymer rubber and a softener for hydrocarbon rubber (hereinafter, “oil-extended ethylene / α-”. There are oil-extended type ones that are "olefin / non-conjugated diene copolymer rubber") and non-oil-extended type ones that do not contain a softening agent for hydrocarbon-based rubber. In this embodiment, oil is used. Although it is intended to be an exhibition type, a non-oil exhibition type can also be preferably used. That is, in the present invention, the ethylene / α-olefin / non-conjugated diene copolymer rubber of the component (G) can be used in either an oil-extended type or a non-oil-extended type, and is a non-oil-extended type or an oil. Only one type of the exhibition type may be used alone, or two or more types may be used in any combination and ratio, and one or more types of the oil exhibition type and one or two types of the non-oil exhibition type may be used. Species and above can also be used in any combination and ratio.

In the case of the oil spread type, the hydrocarbon-based rubber softener contained in the mixture is classified as the hydrocarbon-based rubber softener of the component (E). In this case, a hydrocarbon-based rubber softening agent may be added separately as the component (E). When a hydrocarbon-based rubber softener is added separately, it may be the same as or different from the hydrocarbon-based rubber softener contained in the oil-extending type component (G).

Examples of the hydrocarbon-based rubber softening agent contained in the oil-extending type include those exemplified as the above-mentioned component (E). Further, in a mixture of an oil-extending type ethylene / α-olefin / non-conjugated diene copolymer rubber and a softening agent for hydrocarbon-based rubber, with respect to 100 parts by mass of the ethylene / α-olefin / non-conjugated diene copolymer rubber. , The ratio (oil spread amount) of the rubber hydrocarbon-based rubber softener is usually about 10 to 200 parts by mass.

Examples of the α-olefin in the component (G) include propylene, 1-butene, 3-methyl-1-butene, 1-pentene, 4-methyl-1-pentene, 4,4-dimethyl-1-pentene, 1-. Examples thereof include α-olefins having 3 to 20 carbon atoms, more preferably 3 to 8 carbon atoms, such as hexene, 4-methyl-1-hexene, 1-hexene, 1-octene, 1-decene, and 1-octadecene. It is not particularly limited to these. Among these, propylene, 1-butene, 3-methyl-1-butene and 1-pentene are preferable, and propylene and 1-butene are more preferable, from the viewpoint of crosslinkability and suppression of bloom-out. As the α-olefin, only one type can be used alone, or two or more types can be used in any combination and ratio.

Examples of the non-conjugated diene compound in the component (G) include dicyclopentadiene, 1,4-hexadiene, cyclohexadiene, cyclooctadiene, dicyclooctadiene, 1,6-octadene, 5-methyl-1,4-. Hexadiene, 3,7-dimethyl-1,6-octadene, 1,3-cyclopentadiene, 1,4-cyclohexadiene, 2-methyl-1,5-hexadiene, 6-methyl-1,5-heptadiene, 7- Echiliden norbornene such as methyl-1,6-octadiene, tetrahydroinden, methyltetrahydroinden, 5-isopropyriden-2-norbornene, 5-vinyl-2-norbornene, vinylidene norbornene, 5-ethylidene-2-norbornene (ENB), Examples thereof include methylenenorbornene such as 5-methylene-2-norbornene (MNB), but the present invention is not particularly limited thereto. Among these, dicyclopentadiene, etylidene norbornene and vinylidene norbornene are preferable, and dicyclopentadiene, 5-ethylidene-2-norbornene and vinyliden norbornene are more preferable from the viewpoint of crosslinkability and the like. As the non-conjugated diene, only one type can be used alone, or two or more types can be used in any combination and ratio.

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, and ethylene / propylene.・ Ethylene propylene / non-conjugated diene copolymer rubber (EPDM) such as 1,4-hexadiene copolymer rubber, ethylene / propylene / 5-vinyl-2-norbornene copolymer rubber, and ethylene / 1-butene / Examples thereof include 5-ethylidene-2-norbornene copolymer rubber, but the present invention is not particularly limited thereto. Among these, ethylene / propylene / non-conjugated diene copolymer rubber (EPDM) is preferable from the viewpoint of crosslinkability and suppression of bloom out. As the ethylene / α-olefin / non-conjugated diene copolymer rubber, only one type can be used alone, or two or more types can be used in any combination and ratio.

The content of ethylene units 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 further preferably 60. ~ 80% by mass. When the content of ethylene units is within the above preferable range, a modified elastomer composition having excellent mechanical strength and rubber elasticity tends to be easily obtained.

The content of the α-olefin unit in the ethylene / α-olefin / non-conjugated diene copolymer rubber is not particularly limited, but is preferably 9.5 to 49.5% by mass, more preferably 14 to 45% by mass. %, More preferably 18-38% by mass. When the content of the α-olefin unit is within the above preferable range, a modified elastomer composition having excellent mechanical strength, appropriate flexibility, and rubber elasticity tends to be easily obtained.

Further, the content of the non-conjugated diene unit 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. Yes, more preferably 2 to 10% by mass. When the content of the non-conjugated diene unit is within the above preferable range, the crosslinkability and moldability can be easily adjusted, and a modified elastomer composition having excellent mechanical strength and rubber elasticity tends to be easily obtained.

In the present invention, as the component (G), in particular, the content of ethylene unit is 55 to 75% by mass, the content of propylene unit is 15 to 40% by mass, and dicyclopentadiene, 5-ethylidene-2. An ethylene / propylene / non-conjugated diene copolymer rubber having a content of at least one non-conjugated diene unit selected from the group consisting of -norbornene and vinylidene norbornene having a content of 1 to 10% by mass is preferable.

As the ethylene / α-olefin / non-conjugated diene copolymer rubber of the component (G), only one type can be used alone, or two or more types can be used in any combination and ratio.

<Component (H): Silanol catalyst>
By blending the component (H) silanol catalyst with the modified elastomer composition of the present invention, the modified elastomer composition can be crosslinked between molecules to obtain a crosslinked elastomer composition. That is, the ethylene / α-olefin copolymer rubber of the component (A) in the modified elastomer composition, preferably the component (F) styrene-based block copolymer, and the component (G) ethylene / propylene / non-conjugated diene The alkoxysilyl group introduced by graft modification to the polymer reacts with water and hydrolyzes in the presence of a silanol catalyst to generate silanol groups, and the silanol groups are dehydrated and condensed to form a cross-linking reaction. , And modified ethylene / α-olefin copolymer rubber, styrene block copolymer, and ethylene / propylene / non-conjugated diene copolymer are bonded to each other to produce a crosslinked elastomer composition having excellent heat resistance. Can be made to.

The silanol catalyst of the component (H) that can be used in the present invention includes a group consisting of metal organic acid salts, titanates, borates, organic amines, ammonium salts, phosphonium salts, inorganic acids and organic acids, and inorganic acid esters. One or more compounds selected from the above may be mentioned.

Examples of metal organic acid salts include dibutyltin dilaurate, dioctyltin dilaurate, dibutyltin diacetate, dibutyltin dioctate, stannous acetate, stannous octanoate, cobalt naphthenate, lead octylate, lead naphthenate, and octylic acid. Examples thereof include zinc, zinc caprylate, iron 2-ethylhexanoate, iron octylate, and iron stearate. Examples of the titanate include tetrabutyl ester titanate, tetranonyl titanate ester, and bis (acetylacetonitrile) di-isopropyl titanate. Examples of the organic amine include ethylamine, dibutylamine, hexylamine, triethanolamine, tetramethylguanidine, and pyridine. Examples of the ammonium salt include ammonium carbonate and tetramethylammonium hydroxide. Examples of the phosphonium salt include tetramethylphosphonium hydrooxide. Examples of the inorganic acid and the organic acid include sulfonic acids such as sulfuric acid, hydrochloric acid, acetic acid, stearic acid, maleic acid, toluenesulfonic acid and alkylnaphthylsulfonic acid. Examples of the inorganic acid ester include phosphoric acid esters such as ethylhexyl phosphoric acid ester.

Among these, metal organic acid salts, sulfonic acids, and phosphate esters are preferable, and tin metal carboxylates (for example, dioctyltin dilaurate), alkylnaphthylsulfonic acids, and ethylhexyl phosphate esters are more preferable. ..

The silanol catalysts listed above may be used alone or in combination of two or more.

The silanol catalyst is preferably used as a masterbatch in which a polyolefin and a silanol catalyst are mixed. Examples of the polyolefin that can be used in this masterbatch include polyethylene, polypropylene, and an ethylene / α-olefin copolymer.

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

Among these, in the present invention, high-pressure low-density polyethylene, high-density polyethylene, and ethylene / α-olefin copolymer having an excellent balance between heat resistance and strength are preferable. The ethylene / α-olefin copolymer is more preferably an ethylene / 1-butene copolymer, an ethylene / 4-methyl-1-pentene copolymer, an ethylene / 1-hexene copolymer, or an ethylene / 1-octene. It is an ethylene / α-olefin copolymer such as a copolymer, and this ethylene / α-olefin copolymer contains 2 to 60% by mass of one or more α-olefins and 40 to 98% by mass of ethylene. It is more preferable that and are copolymerized with each other. In the masterbatch of the silanol catalyst, only one of these polyolefins may be used, or two or more of these polyolefins may be blended and used.

When the silanol catalyst is used as a masterbatch in which a polyolefin and a silanol catalyst are mixed, the content of the silanol catalyst in the masterbatch is not particularly limited, but is usually about 0.1 to 5.0% by mass. preferable.

A commercially available product can be used as the silanol catalyst-containing masterbatch, and for example, "LZ082" and "LZ033" manufactured by Mitsubishi Chemical Corporation can be used.

<Mixing ratio>
The modified elastomer composition of the present invention preferably contains the component (A) in an amount of 50 to 95 parts by mass and the component (B) in a proportion of 5 to 50 parts by mass so as to make a total of 100 parts by mass. When the content of the component (A) is not more than the above upper limit and the content of the component (B) is not more than the above lower limit, the injection moldability tends to be excellent. On the other hand, on the contrary, when the content of the component (A) is at least the above lower limit and the content of the component (B) is at least the above upper limit, the compression set tends to be excellent. From this point of view, the ratio of the component (A) in the total of 100 parts by mass of the component (A) and the component (B) is more preferably 55 to 90 parts by mass, and the ratio of the component (B) is more preferable. Is 10 to 45 parts by mass.

The content of the component (C) is preferably 0.01 to 10 parts by mass with respect to a total of 100 parts by mass of the component (A) and the component (B), and from the viewpoint of sufficiently advancing the crosslinking reaction, it is more important. It is preferably 0.05 to 5 parts by mass, more preferably 0.1 to 4 parts by mass.
The content of the component (D) is preferably 0.01 to 3 parts by mass with respect to 100 parts by mass of the total of the component (A) and the component (B), and a sufficient cross-linking reaction is obtained and a good molded appearance is obtained. It is more preferably 0.05 to 2 parts by mass, and further preferably 0.1 to 1 part by mass from the viewpoint of maintaining the above.

When the modified elastomer composition of the present invention contains the component (E), the component (E) (when the oil-extended type is used as the component (G), the hydrocarbon-based rubber softening agent in the component (G) is contained. The content of () is preferably 1 to 200 parts by mass with respect to a total of 100 parts by mass of the component (A) and the component (B). When the content of the component (E) is at least the above lower limit, the effect of improving the flexibility, fluidity, and oil resistance of the component (E) can be sufficiently obtained, and when it is at least the above upper limit, bleed out from the surface. Can be suppressed. From this viewpoint, the content of the component (E) with respect to a total of 100 parts by mass of the component (A) and the component (B) is more preferably 5 to 100 parts by mass.

When the modified elastomer composition of the present invention contains the component (F), the content of the component (F) is 1 to 100 parts by mass with respect to a total of 100 parts by mass of the component (A) and the component (B). Is preferable. When the content of the component (F) is not more than the above lower limit, the value of compression set tends to be reduced by crosslinking, and when it is not more than the above upper limit, the extruder is not loaded and the workability is improved. From this viewpoint, the content of the component (F) with respect to a total of 100 parts by mass of the component (A) and the component (B) is more preferably 5 to 80 parts by mass.

When the modified elastomer composition of the present invention contains the component (G), the content of the component (G) is 1 to 100 parts by mass with respect to a total of 100 parts by mass of the component (A) and the component (B). Is preferable. If the content of the component (G) is at least the above lower limit, the compression set tends to decrease due to crosslinking, and if it is at least the above upper limit, the extruder is not loaded and the workability is improved. From this viewpoint, the content of the component (G) with respect to a total of 100 parts by mass of the component (A) and the component (B) is more preferably 5 to 80 parts by mass.

When the silanol catalyst of the component (H) is blended in the modified elastomer composition of the present invention, the blending amount thereof is not particularly limited, but with respect to 100 parts by mass of the modified elastomer composition excluding the component (H). It is preferably 0.0001 to 0.01 parts by mass, and more preferably 0.0001 to 0.005 parts by mass. When the blending amount of the silanol catalyst is at least the above lower limit, the cross-linking reaction proceeds sufficiently and it tends to be easy to obtain a cross-linked elastomer composition having good heat resistance. It is preferable because cross-linking is less likely to occur and the strand surface and product appearance are less likely to be roughened.

<Other ingredients>
In addition to the above components, the modified elastomer composition of the present invention includes various additives and fillers as other components, resins and elastomers other than the components (A), (B), (F), and (G). Can be contained within a range that does not impair the effects of the present invention.

Examples of the additive include an antioxidant, a heat stabilizer, an ultraviolet absorber, a light stabilizer, an antistatic agent, a crystal nucleating agent, a rust preventive, a viscosity modifier, a foaming agent, a lubricant and a pigment. .. Of these, it is preferable to contain an antioxidant, particularly a phenolic antioxidant, a sulfur-based antioxidant or a phosphorus-based antioxidant. The antioxidant is preferably contained in an amount of 0.1 to 1 part by mass with respect to 100 parts by mass of the elastomer composition of the present invention.

Examples of other resins include polyolefin resins other than the components (A), (B) and (G), polyester resins, polycarbonate resins, polymethylmethacrylate resins, rosin and its derivatives, terpene resins and petroleum resins and their respective. Polyamide-based elastomers such as derivatives, alkyd resins, alkylphenol resins, terpenephenol resins, kumaron inden resins, synthetic terpene resins, alkylene resins, polyamide / polyol copolymers; polyvinyl chloride-based elastomers and polybutadiene-based elastomers, component (F) Other styrene-based elastomers, hydrogenated products thereof, those modified with acid anhydrides to introduce polar functional groups, and those obtained by grafting, random and / or block copolymerizing other monomers. Can be mentioned.

<Manufacturing and molding of modified elastomer composition>
The modified elastomer composition of the present invention comprises the components (A) and (B), the unsaturated silane compound of the component (C), the peroxide of the component (D), the above-mentioned components, and other components, if necessary. Can be produced by mechanically mixing with a known method, for example, a henschel mixer, a V blender, or a tumbler blender, and then mechanically melt-kneading with a known method. For this melt-kneading, a general melt-kneader such as a Banbury mixer, various kneaders, a single-screw extruder or a twin-screw extruder can be used. Further, as shown in Examples described later, when the composition of the present invention is kneaded and produced by a single-screw or twin-screw extruder or the like, it is usually heated to 120 to 240 ° C., preferably 120 to 220 ° C. Can be melt-kneaded with.

In the modified elastomer composition of the present invention, the above-mentioned silanol catalyst is blended, molded by various molding methods such as extrusion molding, injection molding, and press molding, and then exposed to an aqueous atmosphere to carry out a cross-linking reaction between silanol groups. It can be advanced to form a molded product made of a crosslinked elastomer composition. Various conditions can be adopted as the method of exposing to the water atmosphere, the method of leaving in the air containing moisture, the method of blowing air containing water vapor, the method of immersing in a water bath, and the method of sprinkling hot water in a mist form. The method of doing this can be mentioned.

The progress rate of the cross-linking reaction depends on the conditions of exposure to the water atmosphere, but usually the exposure may be in the temperature range of 0 to 130 ° C. and in the range of 5 minutes to 1 week. Particularly preferred conditions are a temperature range of 40 to 90 ° C. and a range of 30 minutes to 24 hours. When using moist air, the relative humidity is selected from the range of 1-100%.

The degree of cross-linking of the cross-linked elastomer composition of the present invention thus obtained can be adjusted by changing the type and blending amount of the silanol catalyst, the conditions (temperature, time) for cross-linking, and the like.

<Duro A hardness>
The crosslinked elastomer composition of the present invention preferably has a Duro A hardness of 30 to 90 as measured according to JIS K6253 (2012) (Duro-A). If the Duro A hardness is 30 or more, the surface hardness is excellent. On the other hand, when the Duro A hardness is 90 or less, the compression set is excellent. From these viewpoints, the Duro A hardness of the crosslinked elastomer composition of the present invention is preferably 40 to 85.

<Use>
The use of the modified elastomer composition and the crosslinked elastomer composition of the present invention is not particularly limited, but automobile parts such as glass run channels, weather strips, weather seals and cushion pads, and construction of packings, gaskets, cushions, anti-vibration rubbers, tubes and the like. , Industrial parts, other sports, miscellaneous goods, medical parts, food parts, household appliances parts, and wire coating materials.
Since the modified elastomer composition and the crosslinked elastomer composition of the present invention are particularly excellent in injection-molded appearance, they are preferably applied as injection-molded products for these applications, but are not limited to injection-molded products.

Hereinafter, specific embodiments of the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples as long as the gist of the present invention is not exceeded. The values of various production conditions and evaluation results in the following examples have meanings as preferable values of the upper limit or the lower limit in the embodiment of the present invention, and the preferable range is the above-mentioned upper limit or lower limit value. , The range specified by the combination of the values of the following examples or the values of the examples may be used.

In the following Examples and Comparative Examples, the raw materials used for preparing the modified elastomer composition and the method for evaluating the obtained modified elastomer composition are as follows.

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

<Component (A) Ethylene / α-olefin copolymer rubber>
(A): INFUSE (registered trademark) 9817 (manufactured by Dow Chemical Co., Ltd.)
Ethylene / α-olefin copolymer rubber α-olefin: 1-octene Density: 0.877 g / cm ³
Melting end point: 124 ° C
MFR: 15 g / 10 minutes (190 ° C, 21.2 N load)

<Component (a) Ethylene / α-olefin copolymer rubber for comparison>
(A): ENGAGE (registered trademark) XLT8677 (manufactured by Dow Chemical Co., Ltd.)
Ethylene / α-olefin copolymer rubber α-olefin: 1-octene Density: 0.870 g / cm ³
Melting end point: 123 ° C
MFR: 0.5 g / 10 minutes (190 ° C, 21.2 N load)

<Component (B) Propylene / Ethylene Random Copolymer>
(B): Novatec (registered trademark) PP MG03BD (manufactured by Japan Polypropylene Corporation)
Propene unit content: 97.5% by mass
Ethylene unit content: 2.5% by mass
MFR: 30 g / 10 minutes (230 ° C, 21.2 N load)

<Propylene homopolymer for component (b) comparison>
(B): Novatec (registered trademark) PP FY6 (manufactured by Japan Polypropylene Corporation)
Propene unit content: 100% by mass
MFR: 2.5 g / 10 minutes (230 ° C, 21.2 N load)

<Component (C) unsaturated silane compound>
(C): KBM-1003 (manufactured by Shin-Etsu Chemical Co., Ltd.)
Vinyl trimethoxysilane:

<Component (D) peroxide>
(D): Trigonox 101-40C (manufactured by Kayaku Akzo Corporation)
A mixture of 40% by mass of 2,5-dimethyl-2,5-di (t-butylperoxy) hexane and 60% by mass of an organic filler.

<Component (E) Hydrocarbon-based rubber softener>
(E) Diana (registered trademark) process oil PW90 (manufactured by Idemitsu Kosan Co., Ltd.)
Paraffin oil 40 ° C kinematic viscosity: 95.54 cSt
Pour point: -15 ° C
Flash point: 272 ° C

<Component (F) Styrene-based block copolymer>
(F): Asaplen (registered trademark) T411 (manufactured by Asahi Kasei Corporation)
Polystyrene-butadiene-styrene block copolymer MFR: 0 g / 10 minutes (190 ° C, 21.2 N load)
Density: 0.94 g / cm ³
Mass ratio of styrene block: 30 mass%

<Component (G) ethylene / α-olefin / non-conjugated diene copolymer rubber>
(G): Mitsui EPT (registered trademark) 3072EPM (manufactured by Mitsui Chemicals, Inc.)
Oil exhibition EPDM
Non-conjugated diene: 5-ethylidene-2-norbornene Ethylene unit content: 64% by mass
Propene unit content: 31% by mass
Non-conjugated diene unit content: 5.4% by mass
Oil spread: 62 parts by mass with respect to 100 parts by mass of EPDM

<Component (H) silanol catalyst>
(H) Silanol catalyst masterbatch (MB) LZ033 (manufactured by Mitsubishi Chemical Corporation)
Linear low density polyethylene containing 0.12% by mass tin catalyst (dioctyl tin dilaurate)

[Evaluation method]
<End point of melting of component (A)>
Using a differential scanning calorimeter manufactured by Hitachi High-Tech Science Co., Ltd., trade name "DSC6220", raise about 5 mg of sample from 20 ° C to 200 ° C at a heating rate of 100 ° C / min according to JIS K7121 (2012). After warming and holding at 200 ° C. for 3 minutes, the temperature was lowered to -10 ° C at a cooling rate of 10 ° C./min, and then supplemented from the thermogram measured when the temperature was raised to 200 ° C. at a heating rate of 10 ° C./min. The peak end point (° C) was calculated and used as the melting end point.

<Evaluation of modified elastomer composition>
(1) Surface hardness The Duro A hardness (after 15 seconds) was measured for the surface hardness evaluation sheet in accordance with JIS K6253 (2012) (Duro-A).

(2) Compression Permanent Strain The sheet for compression permanent strain evaluation was measured at 70 ° C. for 22 hours under 25% compression conditions in accordance with JIS K6262 (2013) standards.

(3) Tactile sensation The surface of the injection molded sheet was touched with a finger, and the stickiness was evaluated according to the following criteria.
Good: There is almost no stickiness.
Impossible: There is stickiness.

(4) Appearance of injection molding The surface condition of the sheet for evaluating the appearance of injection molding (thickness of 100 mm × 100 mm × 2 mm) was visually confirmed, and the flow marks on the surface were evaluated according to the following criteria.
Good: There is no flow mark and the injection molding appearance is excellent.
Impossible: There is a flow mark and the injection molding appearance is inferior.

[Example 1]
As shown in Table 1, the component (A) is 84 parts by mass, the component (B) is 16 parts by mass, the component (C) is 2.10 parts by mass, and the component (D) is 0.21 parts by mass (in the component (D)). 2,5-Dimethyl-2,5-di (t-butylperoxy) hexane alone (40% of the actual amount)), 10 parts by mass of component (F), 21 parts by mass of component (G) 0.1 parts by mass of Armoslip E manufactured by Lion Specialty Chemicals as a mold release agent, 0.1 parts by mass of Tinubin 326 manufactured by BASF as a weather resistant agent, and 7 parts by mass of PC40C manufactured by Dainichi Seika Co., Ltd. as a pigment. The mixture was added and mixed, and mixed with a Henschel mixer for 1 minute. Next, the obtained mixture is charged into the upstream supply port of the same-direction twin-screw extruder (manufactured by Japan Steel Works, Ltd., product number: TEX30, L / D = 46, number of cylinder blocks: 12) by a mass feeder. bottom. Then, 16 parts by mass of the component (E) is supplied from the supply port in the middle of the extruder by the liquid addition pump, and the temperature rises from the upstream part to the downstream part in the range of 120 to 200 ° C. with a total discharge amount of 25 kg / h. It was warmed and melt-kneaded, and pelletized to produce a modified elastomer composition.
To 100 parts by mass of the obtained modified elastomer composition, 4 parts by mass (0.0048 parts by mass as a tin catalyst) of LZ033 was added as the component (H) silanol catalyst MB. Using an in-line screw type injection molding machine (manufactured by Japan Steel Works, product number: J110AD), the composition was injection-molded under the conditions of a cylinder temperature of 220 ° C and a mold temperature of 40 ° C to a thickness of 2 mm ×. A sheet having a width of 100 mm and a length of 100 mm was molded. Further, it was exposed to a constant temperature and humidity chamber at 85 ° C. and 85% RH for 24 hours to prepare a sheet for evaluating surface hardness, compression set, tactile sensation, and injection molding appearance.
Table 1 shows various physical properties and tactile sensations of the evaluation sheet using the modified elastomer composition of Example 1 and evaluation results of the injection molded appearance.

[Comparative Example 1]
The modified elastomer composition of Comparative Example 1 was treated in the same manner as in Example 1 except that the component (a) was used instead of the component (A) and the component (b) was used instead of the component (B). Pellets were obtained, and each evaluation sheet was molded in the same manner. Table 1 shows the evaluation results of various physical properties, tactile sensation, and injection molding appearance.

[Comparative Example 2]
Treatment was carried out in the same manner as in Example 1 except that the component (b) was used instead of the component (B) to obtain pellets of the modified elastomer composition of Comparative Example 2, and each evaluation sheet was molded in the same manner. .. Table 1 shows the evaluation results of various physical properties, tactile sensation, and injection molding appearance.

In Table 1, the description of the blending amounts of the components (E) to (H) and other additives is omitted.

[Evaluation results]
As shown in Table 1, it can be seen that Example 1 corresponding to the modified elastomer composition and the crosslinked elastomer composition of the present invention has good compression permanent strain characteristics, tactile sensation, and injection molded appearance.

Comparative Example 1 is an example in which the component (a) is used instead of the component (A) and the component (b) is used instead of the component (B), and it can be seen that both the tactile sensation and the injection-molded appearance have deteriorated. ..
Comparative Example 2 is an example in which the component (b) is used instead of the component (B), and it can be seen that the injection molding appearance has deteriorated.

Since the modified elastomer composition and the crosslinked elastomer composition of the present invention are excellent in compression-resistant permanent strain resistance, tactile sensation, and injection-molded appearance, various applications in which these are required, such as glass run channels, weather strips, weather seals, cushion pads, and the like, etc. It can be widely and effectively used in automobile parts, civil engineering / building material parts such as building gaskets, sporting goods, industrial parts, home appliances parts, medical parts, food parts, medical equipment parts, electric wires, and miscellaneous goods.

Claims (12)

A modified elastomer composition containing the following components (A) to (C) and grafted with the following components (D).
Component (A): Ethylene / α-olefin copolymer rubber having a density of 0.875 to 0.900 g / cm ³ Component (B): Ethylene with an ethylene unit content of 0.1 to 5.0% by mass. Ethylene random copolymer component (C): unsaturated silane compound component (D): peroxide The modified elastomer composition according to claim 1, wherein the end peak temperature of melting measured by a differential scanning calorimeter (DSC) of the component (A) is 115 ° C. or higher. The modified elastomer composition according to claim 1 or 2, wherein the component (C) is a compound represented by the following formula (1).
RSi (R') ₃ ... (1)
(However, R is an ethylenically unsaturated hydrocarbon group, and R'is a hydrocarbon group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms independently of each other, and at least one of R'. One is an alkoxy group having 1 to 10 carbon atoms.) 1. The modified elastomer composition according to one item. Further, any one of claims 1 to 4, further comprising a component (F): a styrene-based block copolymer in an amount of 1 to 100 parts by mass with respect to a total of 100 parts by mass of the component (A) and the component (B). The modified elastomer composition according to the item. Further, claim that the component (G): ethylene / α-olefin / non-conjugated diene copolymer rubber is contained in an amount of 1 to 100 parts by mass with respect to a total of 100 parts by mass of the component (A) and the component (B). The modified elastomer composition according to any one of 1 to 5. A crosslinked elastomer composition obtained by cross-linking the modified elastomer composition according to any one of claims 1 to 6 with a component (H): silanol catalyst. The crosslinked elastomer composition according to claim 7, wherein the Duro A hardness in JIS K6253 (2012) (Duro-A) is 30 or more and 90 or less. An injection molded product of the modified elastomer composition according to any one of claims 1 to 6. An injection molded product of the crosslinked elastomer composition according to claim 7 or 8. A method for producing a modified elastomer composition, which comprises a step of melt-kneading the following components (A) to (D).
Component (A): Ethylene / α-olefin copolymer rubber having a density of 0.875 to 0.900 g / cm ³ Component (B): Ethylene with an ethylene unit content of 0.1 to 5.0% by mass. Ethylene random copolymer component (C): unsaturated silane compound component (D): peroxide Step of melt-kneading the following components (A) to (D) to obtain a modified elastomer composition,
A step of obtaining an injection molded product by injection molding the modified elastomer composition and the component (H): silanol catalyst.
A method for producing an injection molded product made of a crosslinked elastomer composition, which comprises a step of exposing the injection molded product to a water atmosphere to obtain an injection molded product made of the crosslinked elastomer composition.
Component (A): Ethylene / α-olefin copolymer rubber having a density of 0.875 to 0.900 g / cm ³ Component (B): Ethylene with an ethylene unit content of 0.1 to 5.0% by mass. Ethylene random copolymer component (C): unsaturated silane compound component (D): peroxide