JP7225821B2 - Modified elastomer composition, crosslinked elastomer composition and molding thereof - Google Patents

Description

TECHNICAL FIELD The present invention relates to a modified elastomer composition, a crosslinked elastomer composition and a molded article thereof. More specifically, the present invention relates to a novel low-gloss modified elastomer composition and crosslinked elastomer composition which are excellent in compression set, durability, blocking resistance and moldability, and a molded article using the same.

A thermoplastic elastomer is an elastomer that softens when heated to have fluidity and has rubber elasticity when cooled. Thermoplastic elastomers have molding processability similar to thermoplastic resins, have rubber elasticity, and are recyclable. It is widely used for the purpose of

When used in applications requiring sealability, it is important to have good rubber elasticity, compression set properties, and good moldability. Since a thermoplastic resin such as polyolefin is contained in order to ensure thermoplasticity, the compression set property is insufficient compared to thermosetting rubber, and the applications for which it can be used are limited. On the other hand, thermosetting rubbers such as EPDM have excellent compression set properties, but have the drawback of requiring a long cross-linking process and being inferior in durability.

For example, Patent Documents 1 to 3 propose silane-modified elastomer compositions with improved compression set, but it is necessary to add a large amount of unsaturated silane compound to improve compression set properties. There were problems with economy and productivity. Moreover, the material has a high luster and is unsuitable for use as a sealing material, and there is also the problem that blocking is likely to occur during or after pelletization. Patent Document 4 also proposes a silane-modified elastomer composition, but the compression set (70° C.×22 hours) is only slightly over 50%, which is insufficient. Patent Document 5 proposes a dynamically cross-linkable thermoplastic elastomer composition using a cross-linking agent such as a phenol resin. The properties were unsatisfactory.

WO2016/140251 WO2016/140252 WO2016/140253 Japanese Patent No. 5346285 National Publication No. 2005-516098

The present invention has been made in view of such problems, and its object is to exhibit compression set properties similar to those of conventional thermosetting rubbers, and durability, blocking resistance, and anti-blocking properties similar to those of thermoplastic elastomer compositions. An object of the present invention is to provide a low-gloss modified elastomer composition, a crosslinked elastomer composition, and a molded article thereof having moldability.

As a result of intensive studies to solve the above problems, the present inventors have found ethylene/α-olefin/non-conjugated diene copolymer rubber, ethylene/α-olefin copolymer rubber containing no non-conjugated diene units, and A modified elastomer composition obtained by graft-modifying a composition containing an unsaturated silane compound, or a cross-linked elastomer composition obtained by further cross-linking this composition, has a compression equivalent to that of thermosetting rubber, which was originally thought to be impossible. The inventors have found that it can have permanent set properties, blocking resistance and moldability equivalent to those of thermoplastic elastomers, and have completed the present invention.
That is, the gist of the present invention resides in the following [1] to [9].

[1] A modified elastomer composition comprising the following components (A), (B) and (C) and grafted with the following component (D).
Component (A): Ethylene/α-olefin/non-conjugated diene copolymer rubber Component (B): A non-conjugated diene unit having a melting end peak temperature of 90° C. or higher as measured by a differential scanning calorimeter (DSC) Ethylene / α-olefin copolymer rubber not containing component (C): unsaturated silane compound component (D): peroxide

[2] The content of the component (A) is 5 to 80 parts by mass in a total of 100 parts by mass of the component (A) and the component (B), and the content of the component (B) is the component 95 to 20 parts by mass in a total of 100 parts by mass of (A) and the component (B), and the content of the component (C) is 100 parts by mass in total of the component (A) and the component (B) The modified elastomer composition according to [1], which is 0.01 to 5 parts by mass per part.

[3] In [1] or [2], wherein the amount of component (D) used is 0.01 to 3 parts by mass with respect to a total of 100 parts by mass of component (A) and component (B) A modified elastomeric composition as described.

[4] The modified elastomer composition according to any one of [1] to [3], wherein the component (B) has a density of 0.880 g/cm ³ or less.

[5] Furthermore, component (E): 0.001 to 2 parts by mass of a cross-linking aid with respect to a total of 100 parts by mass of the component (A) and the component (B), [1] to [4] Modified elastomer composition according to any one of.

[6] The modified elastomer composition according to any one of [1] to [5], wherein the component (C) is a compound represented by the following formula (1).
RSi(R′) ₃ (1)
(where R is an ethylenically unsaturated hydrocarbon group, R' is 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.)

[7] Furthermore, component (F): 0.5 to 200 parts by mass of a softening agent with respect to a total of 100 parts by mass of the component (A) and the component (B) of [1] to [6] A modified elastomer composition according to any one of the above.

[8] Component (G): a crosslinked elastomer composition obtained by crosslinking the modified elastomer composition according to any one of [1] to [7] with a silanol condensation catalyst.

[9] A molded article molded from the modified elastomer composition according to any one of [1] to [7] or the crosslinked elastomer composition according to [8].

INDUSTRIAL APPLICABILITY According to the present invention, a low-gloss modified elastomer composition and a crosslinked elastomer composition having excellent compression set properties, good durability, blocking resistance, and moldability, and a molded article using the same are provided. can do.
The modified elastomer composition and crosslinked elastomer composition of the present invention, as well as molded articles using the same, are exposed to applications requiring good rubber elasticity for which conventional thermosetting rubbers have been used, and to severe usage environments. It can be expected to be developed for various uses.

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 arbitrarily modified and implemented without departing from the scope of the present invention. In this specification, when a numerical value or a physical property value is sandwiched before and after the "~", it is used to include the values before and after it.

[Modified elastomer composition]
The modified elastomer composition of the present invention is a modified elastomer composition comprising the following components (A), (B) and (C) and grafted with the component (D), preferably further the following component (E). including ~ (F).
Component (A): Ethylene/α-olefin/non-conjugated diene copolymer rubber Component (B): A non-conjugated diene unit having a melting end peak temperature of 90° C. or higher as measured by a differential scanning calorimeter (DSC) ethylene/α-olefin copolymer rubber component (C): unsaturated silane compound component (D): peroxide component (E): cross-linking aid component (F): softening agent

The content of component (A) is preferably 5 to 80 parts by mass per 100 parts by mass of component (A) and component (B).
The content of component (B) is preferably 95 to 20 parts by mass per 100 parts by mass of component (A) and component (B).
The content of component (C) is preferably 0.01 to 5 parts by mass per 100 parts by mass of component (A) and component (B).
Component (D) is preferably used in an amount of 0.01 to 3 parts by mass per 100 parts by mass of component (A) and component (B).
The content of component (E) is preferably 0.001 to 2 parts by mass per 100 parts by mass of components (A) and (B) combined.
The content of component (F) is preferably 0.5 to 200 parts by mass with respect to the total of 100 parts by mass of components (A) and (B).

[Crosslinked elastomer composition]
The crosslinked elastomer composition of the present invention is obtained by cross-linking the modified elastomer composition of the present invention with the following component (G).
Component (G): Silanol condensation catalyst

<Mechanism>
The mechanism by which the modified elastomer composition and the crosslinked elastomer composition of the present invention exhibit excellent compression set properties, good durability, good blocking resistance, and low gloss is presumed as follows.
Due to the effect of components (C), (D), (G) and component (E), the degree of cross-linking of components (A) and (B) is remarkably increased, and high rubber elasticity can be obtained. is finely dispersed in the component (B), a low gloss is obtained by irregular reflection, and an effect of suppressing blocking is exhibited. Furthermore, since there are no remaining double bonds, good durability can be obtained.

<Component (A): Ethylene/α-olefin/non-conjugated diene copolymer rubber>
The ethylene/α-olefin/non-conjugated diene copolymer rubber of component (A) is a copolymer containing ethylene, an α-olefin and a non-conjugated diene compound as copolymer components. Ethylene/α-olefin/non-conjugated diene copolymer rubber includes a mixture of ethylene/α-olefin/non-conjugated diene copolymer rubber and a softener for hydrocarbon rubber (hereinafter referred to as “oil-extended ethylene/α- There is an oil-extended type that is sometimes referred to as "olefin/non-conjugated diene copolymer rubber") and a non-oil-extended type that does not contain a softener for hydrocarbon rubber. Although extended type copolymer rubbers are intended, non-oil extended types are also suitable. That is, in the present invention, the ethylene/α-olefin/non-conjugated diene copolymer rubber of component (A) can be either oil-extended or non-oil-extended. Only one type of extended type may be used alone, or two or more types may be used in any combination and ratio, one or two or more oil-extended types and one or two non-oil-extended types More than one species can also be used in any combination and ratio.
In the case of the oil-extended type, the softener for hydrocarbon rubber contained in the mixture is classified as the component (F) softener.

Examples of softening agents for hydrocarbon rubber contained in the oil-extended type include those exemplified as component (E) described below. In addition, in the mixture of the oil-extended ethylene/α-olefin/non-conjugated diene copolymer rubber and the softener for hydrocarbon rubber, 100 masses of the oil-extended ethylene/α-olefin/non-conjugated diene copolymer rubber The ratio of the softener for hydrocarbon rubber (oil extension amount) to 1 part is usually about 10 to 200 parts by mass.

Examples of α-olefins in component (A) include propylene, 1-butene, 3-methyl-1-butene, 1-pentene, 4-methyl-1-pentene, 4,4-dimethyl-1-pentene, 1- Examples include α-olefins having 3 to 20 carbon atoms, more preferably 3 to 8 carbon atoms, such as hexene, 4-methyl-1-hexene, 1-heptene, 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 preferred, and propylene and 1-butene are more preferred, from the viewpoint of crosslinkability, bloom-out suppression, and the like. The α-olefins may be used singly or in any combination and ratio of two or more.

Non-conjugated diene compounds in component (A) include dicyclopentadiene, 1,4-hexadiene, cyclohexadiene, cyclooctadiene, dicyclooctadiene, 1,6-octadiene, 5-methyl-1,4- Hexadiene, 3,7-dimethyl-1,6-octadiene, 1,3-cyclopentadiene, 1,4-cyclohexadiene, 2-methyl-1,5-hexadiene, 6-methyl-1,5-heptadiene, 7- ethylidenenorbornenes such as methyl-1,6-octadiene, tetrahydroindene, methyltetrahydroindene, 5-isopropylidene-2-norbornene, 5-vinyl-2-norbornene, vinylidenenorbornene, 5-ethylidene-2-norbornene (ENB); Methylene norbornenes such as 5-methylene-2-norbornene (MNB) are included, but are not particularly limited thereto. Among these, dicyclopentadiene, ethylidenenorbornene and vinylidenenorbornene are preferred from the viewpoint of crosslinkability, and dicyclopentadiene, 5-ethylidene-2-norbornene and vinylidenenorbornene are more preferred. The non-conjugated diene can be used singly or in any combination and ratio of two or more.

Specific examples of the ethylene/α-olefin/nonconjugated diene copolymer rubber include ethylene/propylene/5-ethylidene-2-norbornene copolymer rubber, ethylene/propylene/dicyclopentadiene copolymer rubber, and ethylene/propylene.・Ethylene-propylene-nonconjugated diene copolymer rubber (EPDM) such as 1,4-hexadiene copolymer rubber, ethylene-propylene-5-vinyl-2-norbornene copolymer rubber, ethylene-1-butene- Examples include, but are not limited to, 5-ethylidene-2-norbornene copolymer rubber. Among these, ethylene/propylene/non-conjugated diene copolymer rubber (EPDM) is preferable from the viewpoint of crosslinkability, suppression of bloomout, and the like. The ethylene/α-olefin/non-conjugated diene copolymer rubber may be used alone or in any combination and ratio of two or more.

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 still more preferably 60%. ~80% by mass. When the ethylene unit content is within the preferred range, an elastomer composition having excellent mechanical strength and rubber elasticity tends to be obtained.

The content of α-olefin units in the ethylene/α-olefin/non-conjugated diene copolymer rubber is not particularly limited, but is preferably 10 to 50% by mass, more preferably 15 to 45% by mass, and still more preferably. is 20 to 40% by mass. When the content of the α-olefin unit is within the above preferable range, it tends to be easy to obtain an elastomer composition excellent in mechanical strength, moderate flexibility and rubber elasticity.

Furthermore, the content of non-conjugated diene units in the ethylene/α-olefin/non-conjugated diene copolymer rubber is not particularly limited, but is preferably 0.5 to 30% by mass, more preferably 1 to 20% by mass. Yes, more preferably 2 to 10% by mass. When the content of the non-conjugated diene unit is within the above preferable range, it becomes easy to adjust crosslinkability and moldability, and an elastomer composition having excellent mechanical strength and rubber elasticity tends to be easily obtained.

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

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

The ethylene/α-olefin/non-conjugated diene copolymer rubber of component (A) can be used alone or in any combination and ratio of two or more.

<Component (B): Ethylene/α-olefin copolymer>
The ethylene/α-olefin copolymer of the component (B) used in the present invention has a melting end peak temperature (melting end point) measured by a differential scanning calorimeter (DSC) of 90° C. or higher, and the ethylene unit and an α-olefin unit and no non-conjugated diene unit, that is, an ethylene/α-olefin copolymer excluding component (A). The type of the ethylene/α-olefin copolymer of component (B) is not particularly limited as long as it is such one, and known ethylene/α-olefin copolymers can be appropriately used.

Specific examples of the ethylene/α-olefin copolymer of component (B) include, for example, ethylene/propylene copolymer, ethylene/1-butene copolymer, ethylene/4-methyl-1-pentene copolymer, Examples thereof include copolymers of ethylene and one or more α-olefins having 3 to 10 carbon atoms, such as ethylene/1-hexene copolymers and ethylene/1-octene copolymers.

The type of catalyst used in producing the ethylene/α-olefin copolymer of component (B) is not particularly limited, but examples thereof include Ziegler-Natta catalysts and metallocene catalysts. Among these, an ethylene/α-olefin copolymer produced with a metallocene catalyst is preferred.

The ethylene/α-olefin copolymer of component (B) has a melting end point of 90°C or higher, preferably 115°C or higher. The higher the melting end point of the ethylene/α-olefin copolymer, the more the shape can be maintained by crystals even at high temperatures. However, if the melting end point of the ethylene/α-olefin copolymer is too high, there is a risk of poor appearance due to unmelted lumps during molding temperature rise and premature crystallization (melt fracture) during molding cooling. Therefore, the melting end point of the ethylene/α-olefin copolymer is usually 145° C. or lower. The melting end point of the ethylene/α-olefin copolymer of component (B) is measured by the method described in Examples below.

The density of the ethylene/α-olefin copolymer of component (B) (measured according to JIS K6922-1,2:1997) is preferably 0.850 to 0.910 g/cm ³ , more preferably 0. 0.860 to 0.900 g/cm ³ , more preferably 0.860 to 0.880 g/cm ³ . When the density is equal to or less than the above upper limit value, it tends to be flexible and excellent in sealing performance. Further, when the density is equal to or higher than the above lower limit, the shape can be maintained at room temperature and the hysteresis loss is small, so there is a tendency to be excellent in settling.

The content of ethylene units in the ethylene/α-olefin copolymer of component (B) is preferably 50 to 99% by mass, more preferably 60 to 95% by mass. When the content of ethylene units is within the above range, an elastomer composition having excellent mechanical strength and rubber elasticity tends to be easily obtained.

The melt flow rate (MFR) of the ethylene/α-olefin copolymer of component (B) is the melt flow rate (MFR ), preferably 0.01 to 30 g/10 min. If the MFR is too large, the compression set may increase and the sealability may deteriorate. If the MFR is too small, the load on the motor during modified extrusion will increase, the resin pressure will increase, the productivity will deteriorate, and the surface after molding may become rough. From these points of view, the MFR of the ethylene/α-olefin copolymer of component (B) is more preferably 0.1 g/10 minutes or more and 10 g/10 minutes or less.

The ethylene/α-olefin copolymer of the ethylene/α-olefin copolymer of component (B) is available as a commercial product. For example, Engage (registered trademark) series manufactured by Dow Chemical Co., Kernel (registered trademark) series manufactured by Japan Polyethylene Co., Ltd., Infuse (registered trademark) series manufactured by Dow Chemical Co., Toughmer (registered trademark) series manufactured by Mitsui Chemicals, Mitsui Applicable products can be selected and used from Evolue (trademark registered) series manufactured by Kagaku Co., Ltd.

The ethylene/α-olefin copolymer of component (B) can be used alone or in any combination and ratio of two or more.

<Component (C): Unsaturated silane compound>
Although the unsaturated silane compound of component (C) used in the present invention is not limited, an 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, R 'is independently a hydrocarbon group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms, At least one of them is an alkoxy group having 1 to 10 carbon atoms.

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

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, more preferably a hydrocarbon group having 1 to 4 carbon atoms or 1 to 4 carbon atoms. is an alkoxy group of At least one of R' is preferably an alkoxy group having 1 to 6 carbon atoms, more preferably an alkoxy group having 1 to 4 carbon atoms. The hydrocarbon group of 1 to 10 carbon atoms for R' may be an aliphatic group, an alicyclic group, or an aromatic group, but is preferably an aliphatic group. The alkoxy group having 1 to 10 carbon atoms for 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, etc., or a phenyl and aryl groups represented by groups and the like. When R' is an alkoxy group, specific examples include a methoxy group, an ethoxy group, an isopropoxy group and a β-methoxyethoxy group.

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

As the unsaturated silane compound, among those represented by formula (1), vinyltrialkoxysilanes represented by vinyltrimethoxysilane, vinyltriethoxysilane, propenyltrimethoxysilane and the like are desirable. This is because the vinyl group enables modification of the component (B) into an ethylene/α-olefin copolymer, and the alkoxy group promotes the cross-linking reaction described below. That is, the alkoxy group introduced by graft-modifying the ethylene/α-olefin copolymer with the unsaturated silane compound reacts with water in the presence of a silanol condensation catalyst and hydrolyzes to form a silanol group, thereby producing a silanol group. Due to the dehydration condensation between the groups, the ethylene/α-olefin copolymers bond with each other to cause a cross-linking reaction. In addition, these unsaturated silane compounds may be used individually by 1 type, and may use 2 or more types together.

<Component (D): Peroxide>
Peroxides of component (D) include organic peroxides included in the group of hydroperoxides, dialkyl peroxides, diacyl peroxides, peroxyesters and ketone peroxides. Things are mentioned.

The hydroperoxide group includes cumene hydroperoxide, tertiary butyl hydroperoxide, etc. The dialkyl peroxide group includes dicumyl peroxide, ditertiary butyl peroxide, 2,5-dimethyl-2,5-diter Sharybutylperoxyhexane, 2,5-dimethyl-2,5-ditertiarybutylperoxyhexyne-3, di(2-tertiarybutylperoxyisopropyl)benzene, etc., and the diacyl peroxide group includes lauryl Peroxide, benzoyl peroxide and the like are included. The peroxyester group includes tertiary peroxyacetate, tertiary butyl peroxybenzoate, tertiary butyl peroxyisopropyl carbonate, etc. The ketone peroxide group includes cyclohexanone peroxide, etc. These organic peroxides may be used alone or in combination of two or more.

When used in combination with a cross-linking aid of component (E), which will be described later, a radical generator having a high thermal decomposition temperature is preferred. From this point of view, ditertiarybutyl peroxide, di(2-tertiarybutylperoxyisopropyl)benzene, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane and dicumyl peroxide are preferred.

<Component (E): cross-linking aid>
Examples of the cross-linking aid of component (E) include silicon hydride compounds such as metrohydrogen silicon, sulfur, p-quinonedioxime, p-dinitrosobenzene, 1,3-diphenylguanidine, and other peroxide aids. Agent; polyfunctional vinyl compounds such as divinylbenzene, triallyl cyanurate, triallyl isocyanurate, and diallyl phthalate; ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, trimethylolpropane Polyfunctional (meth)acrylate compounds such as tri(meth)acrylate and allyl (meth)acrylate; having a bismaleimide structure such as N,N'-m-phenylenebismaleimide and N,N'-m-toluylenebismaleimide Compound; trimethylolpropane, trimethylolpropane trimethacrylate, tin chloride (SnCl ₂ ) and the like. Among these, polyfunctional vinyl compounds and polyfunctional (meth)acrylate compounds such as divinylbenzene, triallyl cyanurate, triallyl isocyanurate and diallyl phthalate are preferred.

A phenol resin can also be used as another cross-linking aid. Examples of phenol resins include alkylphenolformaldehyde and brominated alkylphenololformaldehyde.

These cross-linking aids can be used alone or in any combination and ratio of two or more.

<Component (F): Softener>
The modified elastomer composition of the present invention can contain a softening agent as component (F) from the viewpoint of increasing flexibility and improving processability, fluidity and oil resistance.

Examples of the component (F) include mineral oil-based rubber softeners and synthetic resin-based rubber softeners. agents are preferred.

Mineral oil-based rubber softeners are generally mixtures of aromatic hydrocarbons, naphthenic hydrocarbons and paraffinic hydrocarbons, and the ratio of carbon in paraffinic hydrocarbons to all carbon atoms is 50% by mass. Paraffinic oils for the above, naphthenic oils for which the ratio of carbon in naphthenic hydrocarbons is 30 to 45% by mass, aromatic oils for which the ratio of carbon for aromatic hydrocarbons is 35% by mass or more It is called. Among these, the softener is preferably a liquid hydrocarbon rubber softener that is liquid at room temperature (23±2° C.), and more preferably a liquid paraffin oil that is liquid at room temperature.
By using a liquid hydrocarbon-based rubber softening agent as a softening agent, the flexibility and elasticity of the modified elastomer composition of the present invention can be increased, and the processability and fluidity tend to be dramatically improved. .

The paraffinic oil is not particularly limited, but has 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. Further, the pour point is usually -40°C or higher, preferably -30°C or higher, and preferably 0°C or lower. The pour point is usually -40°C or higher, preferably -30°C or higher, and preferably 0°C or lower. Furthermore, the flash point (COC) is usually 200° C. or higher, preferably 250° C. or higher, and usually 400° C. or lower, preferably 350° C. or lower.

The softening agent of component (F) can be used alone or in any combination and ratio of two or more.

When an oil-extended type component (A) is used, an elastomer composition can be prepared as a mixture of an oil-extended ethylene/α-olefin/non-conjugated diene copolymer rubber and a softener for hydrocarbon rubber. The hydrocarbon-based rubber softening agent introduced in (1) also corresponds to the component (F) softening agent. In this case, a softening agent may be added separately as component (F), or a separate softening agent may be used. When the softener is separately added, the softener for hydrocarbon rubber contained in the oil-extended type component (A) and the separately added softener may be the same or different. .

<Component (G): Silanol condensation catalyst>
By blending the component (G) silanol condensation catalyst in the modified elastomer composition of the present invention, the composition can undergo an intermolecular cross-linking reaction, and reacts with water to hydrolyze to form silanol groups, Furthermore, the dehydration condensation between the silanol groups promotes a cross-linking reaction, and the modified elastomers are bonded to each other to form a cross-linked elastomer composition having excellent heat resistance.

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

Examples of metal organic acid salts include dibutyltin dilaurate, dioctyltin dilaurate, dibutyltin diacetate, dibutyltin dioctoate, stannous acetate, stannous octoate, cobalt naphthenate, lead octylate, lead naphthenate, and octylic acid. zinc, zinc caprylate, iron 2-ethylhexanoate, iron octylate, iron stearate and the like. Examples of titanates include tetrabutyl titanate, tetranonyl titanate, bis(acetylacetonitrile) di-isopropyl titanate, and the like. Examples of organic amines include ethylamine, dibutylamine, hexylamine, triethanolamine, dimethylsawyamine, tetramethylguanidine, pyridine and the like. Examples of ammonium salts include ammonium carbonate, tetramethylammonium hydroxide and the like. Examples of phosphonium salts include tetramethylphosphonium hydroxide and the like. Examples of inorganic acids 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 and the like.

Among these, metal organic acid salts, sulfonic acids and phosphoric acid esters are preferred, and metal carboxylates of tin such as dioctyltin dilaurate, alkylnaphthylsulfonic acid and ethylhexyl phosphate are more preferred.

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

The silanol condensation catalyst is preferably used as a masterbatch in which the polyolefin and the silanol condensation catalyst are blended. Polyolefins that can be used in this masterbatch include polyethylene, polypropylene, and ethylene/α-olefin copolymers.

Examples of polyethylene include (branched or linear) ethylene homopolymers such as low-, medium-, and high-density polyethylene; ethylene/propylene copolymers, ethylene/1-butene copolymers, 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 Copolymers, ethylene-based copolymer resins such as ethylene/(meth)acrylic acid ester copolymers, and the like are included. Among these, ethylene/propylene copolymer, ethylene/1-butene copolymer, ethylene/4-methyl-1-pentene copolymer, ethylene/1-hexene copolymer, ethylene/1-octene copolymer, etc. of ethylene/α-olefin copolymer is preferred.

Among these, in the present invention, high-pressure low-density polyethylene, high-density polyethylene, and ethylene/α-olefin copolymer, which are excellent in balance between heat resistance and strength, are preferred. More preferably, the ethylene/α-olefin copolymer is an ethylene/1-butene copolymer, an ethylene/4-methyl-1-pentene copolymer, an ethylene/1-hexene copolymer, or an ethylene/1-octene copolymer. 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 to copolymerize with. Only one kind of these polyolefins may be used for the masterbatch of the silanol condensation catalyst, or two or more kinds thereof may be blended and used.

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

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

<Blending ratio>
The modified elastomer composition of the present invention preferably contains 5 to 80 parts by mass of component (A) and 95 to 20 parts by mass of component (B) so that the total is 100 parts by mass. If the content of component (A) is more than the above upper limit and the content of component (B) is less than the above lower limit, there is a possibility that a good appearance cannot be obtained. If the content of component (A) is less than the above lower limit and the content of component (B) is more than the above upper limit, the gloss will be high and blocking may easily occur. From such a viewpoint, the proportion of component (A) in the total 100 parts by mass of component (A) and component (B) is more preferably 5 to 70 parts by mass, more preferably 5 to 50 parts by mass, The proportion of component (B) is more preferably 95-30 parts by mass, more preferably 95-50 parts by mass.

The content of component (C) with respect to a total of 100 parts by mass of component (A) and component (B) is preferably 0.01 to 5 parts by mass, more preferably 0.01 to 5 parts by mass, from the viewpoint of sufficiently advancing the crosslinking reaction. 0.05 to 5 parts by mass, more preferably 0.1 to 3 parts by mass.

The content of component (D) is preferably 0.01 to 3 parts by mass with respect to a total of 100 parts by mass of components (A) and (B) to obtain a sufficient cross-linking reaction and a smooth molded appearance. From the viewpoint of maintaining the content, it is more preferably 0.05 to 2 parts by mass, still more preferably 0.1 to 1 part by mass.

When the modified elastomer composition of the present invention contains component (E), the content of component (E) is 0.001 to 2 parts by mass per 100 parts by mass of component (A) and component (B). 0.003 to 1 part by mass is preferable from the viewpoint of economic efficiency and sufficient cross-linking reaction.

When the modified elastomer composition of the present invention contains the component (F), the component (F) with respect to a total of 100 parts by mass of the component (A) and the component (B) (when an oil-extended type is used as the component (A), The content of component (A), including the softener for hydrocarbon rubber, is 0.5 to 200 parts by mass. If the content of component (F) is less than the above lower limit, the effect of component (F) for improving flexibility, fluidity, and oil resistance cannot be sufficiently obtained. If the content of component (F) exceeds the above upper limit, there is a risk of bleeding out from the surface. From this point of view, the content of component (F) is preferably 1 to 100 parts by mass, more preferably 5 to 80 parts by mass, per 100 parts by mass of components (A) and (B) combined.

When the silanol condensation catalyst of component (G) is added to the modified elastomer composition of the present invention for cross-linking reaction, the amount added is not particularly limited, but the modified elastomer of the present invention excluding component (G) is used. It is preferably 0.001 to 0.5 parts by mass, more preferably 0.001 to 0.1 parts by mass, per 100 parts by mass of the composition. It is preferable that the amount of the silanol condensation catalyst to be added is at least the above lower limit, because the cross-linking reaction will proceed sufficiently and the heat resistance will tend to be good. If the amount of the silanol condensation catalyst added is less than the above upper limit, premature cross-linking is unlikely to occur in the extruder, and the strand surface and product appearance tend to be less likely to become rough, which is preferable.

<Other ingredients>
In addition to the above components, the modified elastomer composition of the present invention may contain various additives, fillers, resins and elastomers other than components (A) and (B) as other components without impairing the effects of the present invention. It can be contained within the range.

Examples of additives include heat stabilizers, ultraviolet absorbers, light stabilizers, antioxidants, antistatic agents, crystal nucleating agents, rust inhibitors, viscosity modifiers, foaming agents, lubricants and pigments. can. Among 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% by mass based on 100% by mass of the modified elastomer composition of the present invention.

Other resins include, for example, polyolefin resins, polyester resins, polycarbonate resins, polymethyl methacrylate resins, rosin and its derivatives, terpene resins, petroleum resins and their derivatives, alkyd resins, alkylphenol resins, terpenephenol resins, and coumarone. Indene resin, synthetic terpene resin, alkylene resin, olefin elastomer other than components (A) to (B), polyamide elastomer such as polyamide/polyol copolymer; polyvinyl chloride elastomer and polybutadiene elastomer, styrene elastomer, Hydrogenated products thereof, products modified with an acid anhydride or the like to introduce a polar functional group, and products obtained by grafting, random and/or block copolymerizing other monomers, and the like can be mentioned.

<Production and molding of modified elastomer composition>
The modified elastomer composition of the present invention comprises two copolymers of components (A) and (B), an unsaturated silane compound of component (C) and a peroxide of component (C), and optionally crosslinked. Auxiliary agents, softening agents, other components, etc. are mechanically mixed by a known method such as a Henschel mixer, V blender, tumbler blender, etc., and then mechanically melt-kneaded by a known method. can be done. 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 the examples below, when the composition of the present invention is kneaded with a single-screw or twin-screw extruder or the like, it is usually heated to 120 to 240°C, preferably 120 to 220°C. Melt-kneading can be performed at

In the modified elastomer composition of the present invention, the above-mentioned silanol condensation catalyst is blended, molded by various molding methods such as extrusion molding, injection molding, press molding, etc., and then exposed to a water atmosphere to cause a cross-linking reaction between silanol groups. can proceed to a crosslinked elastomeric composition. Various conditions can be adopted for the method of exposing to a water atmosphere, including a method of leaving in air containing moisture, a method of blowing air containing water vapor, a method of immersion in a water bath, and a method of sprinkling hot water in the form of a mist. and the like.

In this case, the hydrolyzable alkoxy group derived from the unsaturated silane compound used for graft modification of components (A) and (B) reacts with water in the presence of a silanol condensation catalyst and hydrolyzes to form a silanol group. Further, the silanol groups undergo dehydration condensation to proceed with the cross-linking reaction, and the modified elastomers are bonded to each other to form a cross-linked elastomer composition.

The rate of progress of the cross-linking reaction is determined by the conditions of exposure to the water atmosphere, but the temperature range is usually 0 to 130° C. and the exposure time is 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 thus obtained can be adjusted by changing the type and amount of the silanol condensation catalyst and the conditions (temperature, time) for cross-linking.

<Application>
Applications of the modified elastomer composition and crosslinked elastomer composition of the present invention are not particularly limited. It can be suitably used for construction, industrial parts, other sports, miscellaneous goods, medical parts, food parts, household appliance parts, and electric wire coating materials.

Specific embodiments of the present invention will be described in more detail below using examples, but the present invention is not limited by the following examples as long as the gist thereof is not exceeded. Various production conditions and values of evaluation results in the following examples have the meaning of preferred values of the upper limit or the lower limit in the embodiments of the present invention, and the preferred range is the above-described upper limit or lower limit value. , the range defined by the values in the following examples or a combination of the values in the examples.

In the following examples and comparative examples, raw materials used for preparation of elastomer compositions and methods for evaluating the obtained elastomer compositions are as follows.

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

<Oil-extended or non-oil-extended ethylene/α-olefin/non-conjugated diene copolymer rubber>
(A-1): Mitsui EPT (registered trademark) 3072EPM (manufactured by Mitsui Chemicals, Inc.)
Metallocene-catalyzed oil-extended EPDM
Non-conjugated diene: 5-ethylidene-2-norbornene Diene content: 5.4% by mass
Ethylene unit content: 64% by mass
Mooney viscosity: 51 ML (value after 1 minute of preheating and 4 minutes after rotation) 125°C
Oil extension amount: 40 parts by mass (A-2): Mitsui EPT (registered trademark) 3092PM (manufactured by Mitsui Chemicals, Inc.)
Metallocene-catalyzed non-oil-extended EPDM
Non-conjugated diene: 5-ethylidene-2-norbornene Diene content: 5.4% by mass
Ethylene unit content: 66% by mass
Mooney viscosity: 61 ML (value after 1 minute of preheating and 4 minutes after rotation) 125°C
(A-3): JSR EP (registered trademark) EP501EC (manufactured by JSR)
V catalyst oil-extended EPDM
Non-conjugated diene: 5-ethylidene-2-norbornene Diene content: 5.5 mass%
Ethylene unit content: 66% by mass
Mooney viscosity: 54ML (value after 1 minute of preheating and 4 minutes after rotation) 125°C
Oil extension amount: 40 parts by mass (A-4): JSR EP (registered trademark) EP505EC (manufactured by JSR)
V catalyst oil-extended EPDM
Non-conjugated diene: 5-ethylidene-2-norbornene Ethylene unit content: 67 mass%
Diene content: 4.5% by mass
Mooney viscosity: 64ML (value after 1 minute of preheating and 4 minutes after rotation) 125°C
Oil extension amount: 100 parts by mass (A-5): JSR EP (registered trademark) EP57C (manufactured by JSR)
V catalyst-based non-oil-extended EPDM
Non-conjugated diene: 5-ethylidene-2-norbornene Ethylene unit content: 66 mass%
Diene content: 4.5% by mass
Mooney viscosity: 58ML (value after 1 minute of preheating and 4 minutes after rotation) 125°C

<Ethylene/α-olefin copolymer>
(B-1): Engage (registered trademark) XLT8677 (manufactured by Dow Chemical Company)
Ethylene / α-olefin copolymer α-olefin: 1-octene MFR: 0.5 g / 10 minutes (190 ° C., 21.2 N load)
Density: 0.87g/ ^cm3
Melting end point: 123°C
(B-2): Tafmer (registered trademark) A0550S (manufactured by Mitsui Chemicals, Inc.)
Ethylene / α-olefin copolymer α-olefin: butene MFR: 0.5 g / 10 minutes (190 ° C., 21.2 N load)
Density: 0.86g/ ^cm3
Melting end point: 58°C
(The method for measuring the melting end points of components (B-1) and (B-2) is as described below.)

<Unsaturated silane compound>
(C) Vinyltrimethoxysilane: KBM-1003 (manufactured by Shin-Etsu Chemical Co., Ltd.)

<Organic Peroxide>
(D-1) di(2-tert-butylperoxyisopropyl)benzene: Perbutyl P (manufactured by NOF Corporation)
(D-2) Ditertiary butyl peroxide: Perbutyl D (manufactured by NOF Corporation)
(D-3) 2,5-dimethyl-2,5-di(t-butylperoxy)hexane: Kayahexa AD40C (manufactured by Kayaku Akzo Co., Ltd., 2,5-dimethyl-2,5-di(t-butyl) Peroxy) A mixture of 40% by mass of hexane and 60% by mass of an organic filler)

<Crosslinking aid>
(E-1) Divinylbenzene (a mixture of 55% by mass of divinylbenzene and 45% by mass of ethylvinylbenzene manufactured by Wako Pure Chemical Industries, Ltd.)
(E-2) triallyl cyanurate (manufactured by Wako Pure Chemical Industries, Ltd.)

<Softener>
(F) Softener for paraffin rubber: Diana (registered trademark) Process Oil PW90 (manufactured by Idemitsu Kosan Co., Ltd., paraffin oil)
Kinematic viscosity at 40°C: 95.54 cSt (centistokes)
Pour point: -15°C
Flash point: 272°C

<Catalyst masterbatch (MB)>
(G) Silanol condensation catalyst MB: LZ033 (manufactured by Mitsubishi Chemical Corporation, linear low-density polyethylene containing 1.2% tin catalyst (dioctyltin dilaurate), MFR of low-density polyethylene: 2 g/10 minutes (190°C, 21. 2N load), density of low-density polyethylene: 0.92 g/cm ³ )

[Component (B): Measurement of melting end point of ethylene/α-olefin copolymer]
Using a differential scanning calorimeter manufactured by Hitachi High-Tech Science Co., Ltd., trade name "DSC6220", according to JIS K7121, about 5 mg of the sample was heated from 20 ° C. to 200 ° C. at a heating rate of 100 ° C./min, After holding at 200 ° C. for 3 minutes, the temperature was lowered to -10 ° C. at a cooling rate of 10 ° C./min, and then the temperature was increased to 200 ° C. at a heating rate of 10 ° C./min. (°C) was calculated as the melting end point.

[Evaluation method]
Various evaluation methods for the elastomer compositions in Examples and Comparative Examples are shown below.

(1) Surface Hardness The Duro-A hardness (after 15 seconds) of the obtained molded sheet was measured according to JIS K6253 (Duro-A).

(2) Compression set The obtained molded sheet was measured under conditions of 25% compression at 70°C for 22 hours in accordance with JIS K6262.

(3) Gloss The gloss of the obtained molded sheet was measured according to JIS Z8741.

(4) Blocking property When the modified elastomer composition was kneaded during strand cutting, the entire composition was blocked and turned into lumps, and the strand cutting itself was not possible. A case where blocking occurred was indicated by Δ, and a case where there was no blocking was indicated by ○.

[Example 1]
Each raw material other than (F) was blended according to the raw material composition shown in Table 1 and mixed for 1 minute with a Henschel mixer. Next, the obtained mixture is introduced into the upstream supply port of a co-directional twin-screw extruder (manufactured by Japan Steel Works, Ltd., product number: TEX30, L/D = 46, number of cylinder blocks: 12) with a mass feeder. bottom. Then, the component (F) is supplied from a supply port in the middle of the extruder by a liquid addition pump, and the temperature is raised from the upstream part to the downstream part in the range of 120 to 200 ° C. at a total discharge rate of 25 kg / h. Melt-kneading was performed, and the strands were cut and pelletized to produce a modified elastomer composition. To 100 parts by mass of the modified elastomer composition thus obtained, 4 parts by mass of LZ033 as the component (G) silanol condensation catalyst MB (0.048 parts by mass as a tin catalyst) was added to obtain a crosslinked elastomer composition containing the catalyst MB. Obtained. Using an in-line screw type injection molding machine (manufactured by Toshiba Machine Co., Ltd., product number: IS130), the composition was injected under the conditions of an injection pressure of 50 MPa, a cylinder temperature of 220°C, and a mold temperature of 40°C. It was molded into a sheet of 2 mm thick×120 mm wide×80 mm long. Furthermore, it was exposed to a constant temperature and humidity machine under conditions of 85° C. and 85% RH for 24 hours to obtain a sheet for surface hardness, compression set and gloss evaluation.
Table 1 shows the evaluation results of the obtained elastomer composition of Example 1.

[Examples 2 to 14 and Comparative Examples 1 to 5]
Pellets of the modified elastomer compositions of Examples 2 to 14 and Comparative Examples 1 to 5 were obtained by treating in the same manner as in Example 1, except for changing the raw material formulations shown in Tables 1 to 3, and evaluated in the same manner. A sheet for use was molded and evaluated in the same manner. The results are shown in Tables 1-3.

In Tables 1 to 3, the components (A-1), (A-3), and (A-4) are not the actual blending amounts, but the components (A-1), (A-1), ( A-3) and (A-4) are indicated by the compounding amount of EPDM alone.
Similarly, for component (D-3), the amount of 2,5-dimethyl-2,5-di(t-butylperoxy)hexane alone in component (D) is not the actual amount. 40% of the actual compounding amount), and the component (E-1) is not the actual compounding amount, but the compounding amount of divinylbenzene alone in the component (E-1) (actual compounding amount 55%). .

[Evaluation results]
As shown in Tables 1 and 2, Examples 1 to 14, which correspond to the elastomer composition of the present invention, are all excellent in compression set and blocking resistance, and have low gloss.
On the other hand, it can be seen that the elastomer compositions of Comparative Examples 1 to 5 are insufficient in any one of compression set, low gloss, and blocking resistance.
These results demonstrate that the elastomer composition of the present invention has good sealing properties, molding appearance, and blocking resistance.

Since the elastomer composition of the present invention is excellent in compression set, molded appearance, and blocking resistance, it can be used in various applications requiring these properties, such as glass run channels, weather strips and other automobile parts, construction gaskets and other civil engineering and construction material parts, It can be widely and effectively used in sporting goods, industrial parts, home electric appliance parts, medical parts, food parts, medical equipment parts, electric wires, miscellaneous goods and the like.

Claims (9)

A modified elastomer composition comprising the following components (A), (B) and (C) and grafted with the following component (D) ,
The content of the component (A) is 5 to 50 parts by mass in a total of 100 parts by mass of the component (A) and the component (B), and the content of the component (B) is the component (A). and the component (B) in an amount of 95 to 50 parts by mass per 100 parts by mass in total .
Component (A): Ethylene/α-olefin/non-conjugated diene copolymer rubber Component (B): A non-conjugated diene unit having a melting end temperature of 90° C. or higher as measured by a differential scanning calorimeter (DSC) Ethylene / α-olefin copolymer rubber not containing component (C): unsaturated silane compound component (D): peroxide 2. The modified elastomer composition according to claim 1, wherein the content of said component (C) is 0.01 to 5 parts by mass with respect to a total of 100 parts by mass of said component (A) and said component (B). . 3. The modified elastomer composition according to claim 1, wherein the amount of said component (D) used is 0.01 to 3 parts by mass with respect to a total of 100 parts by mass of said component (A) and said component (B). thing. The modified elastomer composition according to any one of claims 1 to 3, wherein the component (B) has a density of 0.880 g/cm ³ or less. 5. The composition according to any one of claims 1 to 4, further comprising 0.001 to 2 parts by mass of a component (E): a cross-linking aid with respect to a total of 100 parts by mass of the component (A) and the component (B). modified elastomer composition. The modified elastomer composition according to any one of claims 1 to 5, wherein the component (C) is a compound represented by the following formula (1).
RSi(R′) ₃ (1)
(where R is an ethylenically unsaturated hydrocarbon group, R' is 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.) 7. The component (F) according to any one of claims 1 to 6, further comprising 0.5 to 200 parts by mass of a softening agent with respect to a total of 100 parts by mass of the component (A) and the component (B). A modified elastomeric composition. Component (G): a crosslinked elastomer composition obtained by crosslinking the modified elastomer composition according to any one of claims 1 to 7 with a silanol condensation catalyst. A molded article molded from the modified elastomer composition according to any one of claims 1 to 7 or the crosslinked elastomer composition according to claim 8.