JP5675518B2 - Composition and cross-linked product thereof - Google Patents

Description

  The present invention relates to a rubber composition that has excellent processability and has excellent rubber elasticity and shape memory when crosslinked.

  Ethylene / α-olefin copolymer rubber and ethylene / α-olefin / non-conjugated polyene copolymer rubber (EPDM) have no unsaturated bond in the main chain, so they have better weather resistance than conjugated diene rubbers. Excellent in heat resistance and ozone resistance.

  Utilizing these characteristics, a rubber composition containing these copolymer rubbers, a crosslinked product of the rubber composition, and a foamed product of the composition are used for automobile industrial parts, industrial rubber products, electrical insulating materials, Widely used in civil engineering materials and rubber products such as rubberized fabric. Among these, hoses and tube-shaped products are often S-shaped, L-shaped, or a combination of them, and are three-dimensionally folded. Recently, automobiles have become more compact and more complicated. Is increasing.

  Currently, these products are made by first forming unvulcanized rubber into a single-layer or braided three-layer hose using an extruder, and then inserting a mandrel with a desired shape into the hose hollow. It is manufactured by simultaneously performing vulcanization and bowl shape (shape bowl shape) in a steam can or an air vulcanization tank. However, since this method has poor production efficiency and many product defects, there is a growing need for rubber materials having shape memory properties.

  As a shape memory rubber, an EPDM / resin alloy in which a polyolefin resin having an average dispersed particle diameter of 0.1 to 20 μm is microdispersed in ethylene / α-olefin / non-conjugated polyene copolymer rubber (EPDM) is proposed, It has been reported that it exhibits good shape memory properties and rubber elasticity (see, for example, Patent Document 1).

JP-A-9-309986

  The alloy described in Patent Document 1 may be shaped or may be further blended with so-called rubber additives such as fillers, extender oils, and cross-linking agents. It was sometimes difficult. In addition, when trying to reduce the viscosity at the time of blending by heating at a relatively high temperature, for example, when a crosslinking agent is contained, the crosslinking reaction proceeds to some extent, so that the moldability at the time of shaping is improved. There was also an impact.

  An object of the present invention is to provide a composition excellent in molding processability, which is excellent in shape memory property and rubber elasticity of a crosslinked product of the composition.

The first of the present invention relates to the composition shown below.
[1] One kind selected from ethylene / α-olefin / non-conjugated polyene copolymer (A) 100 parts by weight and the following (i) to (ii) and an α-olefin having 3 to 20 carbon atoms A composition containing 15 to 40 parts by weight of a polymer (B) whose main component is a structural unit derived from
(I) a melting point measured by a differential scanning calorimeter (DSC) of 125 to 245 ° C.,
(Ii) The polystyrene-equivalent number average molecular weight (Mn) measured by gel permeation chromatography (GPC) is 1,000 to 15,000.

[2] The composition according to [1], wherein the polymer (B) contains a propylene-derived structural unit as a main component.
[3] Constituent units derived from one type selected from α-olefins having 3 to 20 carbon atoms in which the proportion of the structural units derived from the α-olefins having 3 to 20 carbon atoms in the polymer (B) The composition according to [1] or [2], which is 50 mol% or more with respect to 100 mol% in total with other structural units.
[4] The composition according to [1] or [2], wherein the density of the polymer (B) measured by (iii) density gradient tube method is 820 to 920 kg / m ³ .

[5] The composition according to any one of [1] to [4], further comprising a filler.
[6] The composition according to any one of [1] to [5], further comprising a plasticizer.
[7] The composition according to any one of [1] to [6], further comprising a crosslinking agent.

The second of the present invention relates to the following crosslinked bodies and the like.
[8] A crosslinked product obtained by crosslinking the composition according to [1] to [7].
[9] A weather strip, a grommet, a hose, or a sealing material for automobiles comprising the crosslinked product according to [8].

  ADVANTAGE OF THE INVENTION According to this invention, the rubber composition which is excellent in molding processability, and shows favorable shape memory property and rubber elasticity when bridge | crosslinking can be provided.

(A) Ethylene / α-olefin / non-conjugated polyene copolymer The composition of the present invention contains an ethylene / α-olefin / non-conjugated polyene copolymer (A). The ethylene / α-olefin / non-conjugated polyene copolymer (A) comprises a structural unit derived from ethylene, a structural unit derived from an α-olefin having 3 or more carbon atoms (preferably 3 to 20), and a non-conjugated polyene. And is a random copolymer.

  Specific examples of the α-olefin in the ethylene / α-olefin / non-conjugated polyene copolymer (A) include propylene, 1-butene, 4-methylpentene-1, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-nonadecene, 1-eicocene, 9-methyldecene-1, 11-methyldodecene-1, 12-ethyltetradecene-1, and the like are included. Of these, propylene, 1-butene, 4-methylpentene-1, 1-hexene and 1-octene are preferable, and propylene is particularly preferable. These α-olefins are used alone or in combination of two or more.

  Specific examples of the nonconjugated polyene in the ethylene / α-olefin / nonconjugated polyene copolymer (A) include 1,4-hexadiene, 3-methyl-1,4-hexadiene, and 4-methyl-1,4-hexadiene. 5-methyl-1,4-hexadiene, 4,5-dimethyl-1,4-hexadiene, 7-methyl-1,6-octadiene, 8-methyl-4-ethylidene-1,7-nonadiene and 4-ethylidene Linear unconjugated dienes such as 1,7-undecadiene; methyltetrahydroindene, 5-ethylidene-2-norbornene, 5-methylene-2-norbornene, 5-isopropylidene-2-norbornene, 5-vinylidene-2-norbornene 6-chloromethyl-5-isopropenyl-2-norbornene, 5-vinyl-2-norbornene, 5-isopropenyl-2-norbornene, 5-isobutenyl-2-norbornene, cyclopentadiene And cyclic non-conjugated dienes such as norbornadiene; 2,3-diisopropylidene-5-norbornene, 2-ethylidene-3-isopropylidene-5-norbornene, 2-propenyl-2,2-norbornadiene, 4-ethylidene-8- And trienes such as methyl-1,7-nonadiene. Of these, 5-ethylidene-2-norbornene and 5-vinyl-2-norbornene are preferable. These non-conjugated polyenes are used alone or in combination of two or more.

  In the ethylene / α-olefin / non-conjugated polyene copolymer (A), the molar ratio of the structural unit derived from ethylene (a) and the structural unit derived from α-olefin (b) [(a) / (b )] Is not particularly limited, but is usually 50/50 to 90/10, preferably 55/45 to 85/15. The iodine value of the ethylene / α-olefin / non-conjugated polyene copolymer (A) is not particularly limited, but is usually 1 to 40, preferably 2 to 35, and more preferably 3 to 30.

  The intrinsic viscosity [η] of the ethylene / α-olefin / non-conjugated polyene copolymer (A) is not particularly limited, but the intrinsic viscosity [η] measured in decalin at 135 ° C. is usually 1.0. It is -5.0 dl / g, Preferably it is 1.0-4.0 dl / g.

  Specific examples of the ethylene / α-olefin / non-conjugated polyene copolymer (A) include ethylene / propylene / 5-ethylidene-2-norbornene random copolymer, ethylene / propylene / 5-ethylidene-2-norbornene / 5 -Vinyl-2-norbornene random copolymer is included.

  The copolymer (A) as described above can be produced, for example, by the method described in “New polymer production process (issued by Industrial Research Council, p365-p380 (1994) Chapter 12 EPDM)”. Yes, but not limited to this.

(B) A polymer mainly composed of one type selected from structural units derived from α-olefins having 3 to 20 carbon atoms The composition of the present invention is selected from structural units derived from α-olefins having 3 to 20 carbon atoms. The polymer (B) which has 1 type as a main component is included.

  The one kind of C3-C20 α-olefin in the polymer (B) is specifically propylene, 1-butene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1- Octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-nonadecene, 1-eicocene, 9-methyldecene- It is preferably selected from 1,11-methyldodecene-1 and 12-ethyltetradecene-1.

  The polymer (B) is a structural unit derived from one type selected from α-olefins having 3 to 20 carbon atoms (a structural unit of the main component) and a structural unit other than the one type of α-olefin. When the total is defined as 100 mol%, it means a polymer in which the structural unit derived from one kind selected from the α-olefin having 3 to 20 carbon atoms is 50 mol% or more.

  In this case, the constituent unit other than the constituent unit of the main component is a constituent unit derived from an α-olefin having 2 to 20 carbon atoms, and is preferably other than the constituent unit of the main component. Examples of the structural unit other than the structural unit of the main component include ethylene and the above-mentioned α-olefin having 3 to 20 carbon atoms.

  When a constituent unit other than the constituent unit of the main component is present in the polymer (B), the total amount is when the sum of the constituent unit of the main component and the other constituent unit is 100 mol%. Usually, it is 50 mol% or less, preferably 49 mol% or less, and the lower limit is not limited as long as it is a value exceeding 0 mol%, for example, 0.01 mol%.

  In the case where a constituent unit other than the constituent unit of the main component exists in the polymer (B), the constituent unit of the main component is 100 mol% in total of the constituent unit of the main component and the other constituent units. The upper limit is usually 50 mol% or more, preferably 51 mol% or more, and the upper limit is not particularly limited as long as it is less than 100 mol%, for example, 99.99 mol%.

  From the viewpoint of heat resistance, the polymer (B) is preferably a polymer containing propylene as a main component or a polymer containing 4-methyl-1-pentene as a main component, and particularly preferably propylene as a main component. It is a polymer. The polymer (B) is at least one selected from a propylene homopolymer, a copolymer of propylene and ethylene, and propylene and an α-olefin having 4 to 20 carbon atoms, among polymers mainly composed of propylene. More preferred are copolymers with seed olefins.

  Furthermore, the polymer (B) satisfies the following (i) to (ii).

  The melting point of the polymer (B) measured by (i) a differential scanning calorimeter (DSC) is 125 to 245 ° C. For example, in the case of a polymer having a propylene structural unit in a proportion of 50 mol% or more, the preferable melting point is 125 ° C to 170 ° C, more preferably 130 to 165 ° C, and particularly preferably 140 to 165 ° C. The crosslinked product (eg, vulcanized product) of the composition containing the polymer (B) having the melting point in the above range and the copolymer (A) has rubber elasticity even after being subjected to stress at a relatively high temperature. Easy to hold.

The number average molecular weight (Mn) in terms of polystyrene measured by (ii) gel permeation chromatography (GPC) of the polymer (B) is 1 × 10 ³ to 15 × 10 ³ , preferably 3 × 10 ^{3 to} 14. × 10 ^3, more preferably from ^{5 × 10 3 ~13 × 10 3} . The crosslinked body (vulcanized body) of the composition containing the polymer (B) having the number average molecular weight in this range and the copolymer (A) is particularly excellent in rubber elasticity. The reason for this is not clear, but the polymer (B) having a number average molecular weight in this range has an appropriate viscosity, and the polymer (B) is appropriately dispersed in the copolymer (A). It is considered that the polymer (B) hardly inhibits rubber elasticity in the crosslinked body.

  The polymer (B) preferably further satisfies at least one selected from the following (iii) and (iv).

The density of the polymer (B) measured by (iii) density gradient tube method is 820 to 920 kg / m ³ . In particular, when the polymer (B) is a polymer containing propylene as a main component, the density is preferably 890 to 920 kg / cm ³ .

  The polymer (B) has (iv) penetration of 5 dmm or less, preferably 3 dmm or less, more preferably 1 dmm or less. The penetration may be measured at 25 ° C. according to a method standardized in JIS K2207.

 As a polymer (B) used for this invention, what was manufactured by the conventionally well-known method may be used, for example, a commercial item may be used.

[Other ingredients]
In the composition of the present invention, the polymer (B) is microdispersed in a molten state in the ethylene / α-olefin / non-conjugated polyene random copolymer (A) according to the intended use and performance of the crosslinked product. Various known compounding agents generally used in the manufacture of rubber products may be blended together with the resin. Examples of compounding agents include fillers, softeners, vulcanization aids, anti-aging agents, processing aids, alkoxysilane compounds, cross-linking agents, cross-linking aids, activators, reaction inhibitors, colorants, dispersants, Flame retardants, plasticizers, antioxidants, scorch inhibitors, ultraviolet absorbers, antistatic agents, lubricants, fungicides, peptizers, tackifiers, various dyes such as disperse dyes and acid dyes as representative examples, Additives such as inorganic and organic pigments, surfactants, and paints, and if necessary, foaming compounds such as foaming agents and foaming aids, and defoaming agents are within a range that does not impair the purpose of the present invention. It can select suitably and can mix | blend an appropriate compounding quantity.

[Filler]
The filler that can be contained in the composition of the present invention is not particularly limited as long as it is a filler that is usually used as a filler for synthetic rubber. Examples of fillers include SRF, GPF, FEF, MAF, HAF, ISAF, SAF, FT, MT, etc. carbon black, silica, activated calcium carbonate, light calcium carbonate, heavy calcium carbonate, fine talc, fine powder silica Acids, talc, clay, etc., or those obtained by treating the surface of these inorganic substances with a silane coupling agent or the like can be used.

  Examples of commercially available carbon black include “Asahi # 55G”, “Asahi # 50HG”, “Asahi # 60G” (trade name; manufactured by Asahi Carbon Co., Ltd.), “Seast V”, “Seast SO” (trade name) ; Manufactured by Tokai Carbon Co., Ltd.).

The specific surface area of the filler is preferably 5 to 120 m ² / g. The content of the filler in the composition may be in the range of, for example, 1 to 240 parts by weight, preferably 5 to 200 parts by weight, and more preferably 10 to 100 parts by weight with respect to 100 parts by weight of the copolymer (A). .

[Softener]
The softener that can be included in the composition of the present invention may be any softener that is usually used for rubber. Specifically, petroleum-based softeners such as process oil, lubricating oil, paraffin, liquid paraffin, petroleum asphalt, and petroleum jelly; coal-tar softeners such as coal tar and coal tar pitch; castor oil, linseed oil, rapeseed oil, Fat oil-based softeners such as coconut oil; tall oil; sub; waxes such as beeswax, carnauba wax and lanolin; fatty acids and fatty acid salts such as ricinoleic acid, palmitic acid, barium stearate, calcium stearate and zinc laurate; petroleum Examples thereof include synthetic polymer materials such as resin, atactic polypropylene, and coumarone indene resin. Of these, petroleum softeners are preferably used, and process oil is particularly preferably used.

  The content of the softening agent in the composition can be appropriately selected depending on the use of the rubber molded body, but is usually 1 part by mass or more with respect to 100 parts by weight of the ethylene / α-olefin / nonconjugated polyene random copolymer (A). 150 parts by mass or less, preferably 5 parts by mass or more and 130 parts by mass or less, more preferably 10 parts by mass or more and 100 parts by mass or less.

Cross-linking agent (C)
The composition of the present invention preferably includes an ethylene / α-olefin / non-conjugated polyene random copolymer (A), a specific polymer (B), and a crosslinking agent (C). one of. That is, the composition of the present invention is usually used as a crosslinked product. Examples of the crosslinking agent contained in the composition of the present invention include vulcanizing agents such as sulfur and sulfur compounds, and organic peroxides. Among them, sulfur is preferable.

  Specific examples of sulfur as a cross-linking agent include powdered sulfur, precipitated sulfur, colloidal sulfur, surface treated sulfur, insoluble sulfur and the like. Specific examples of the sulfur compound as the crosslinking agent include sulfur chloride, sulfur dichloride, and polymer polysulfide.

  The sulfur compound as a crosslinking agent is a compound that releases active sulfur at the vulcanization temperature. Examples of the sulfur compound as the crosslinking agent include morpholine disulfide, alkylphenol disulfide, tetramethylthiuram disulfide, dipentamethylenethiuram tetrasulfide, selenium dimethyldithiocarbamate and the like.

  Sulfur or a sulfur compound as a crosslinking agent is used alone or in combination of two or more.

  The content of sulfur and a sulfur compound as a crosslinking agent in the composition is usually 0.1 to 10 parts by weight, preferably 100 parts by weight of ethylene / α-olefin / non-conjugated polyene random copolymer (A), preferably Although it may be 0.3-5 parts by weight, it is desirable to determine the optimum amount as appropriate according to the required physical properties.

  When sulfur or a sulfur compound is used as the crosslinking agent, it is preferable to use a vulcanization accelerator in combination.

  Specific examples of the vulcanization accelerator include N-cyclohexyl-2-benzothiazole sulfenamide, N-oxydiethylene-2-benzothiazol sulfenamide, N, N-diisopropyl-2-benzothiazol sulfenamide, and the like. Sulfenamide compounds; 2-mercaptobenzothiazole, 2- (2 ′, 4′-dinitrophenyl) mercaptobenzothiazole, 2- (4′-morpholinodithio) benzothiazole, dibenzothiazyl disulfide and other thiazole compounds; Guanidine compounds such as diphenylguanidine, diorthotolylguanidine, diorthonitrile guanidine, orthonitrile biguanide, diphenylguanidine phthalate; acetaldehyde-aniline reactant, butyraldehyde-aniline condensate, hexamethylenetetramine, acetaldehyde Aldehyde amines such as deammonia or aldehyde-ammonia compounds; imidazoline compounds such as 2-mercaptoimidazoline; Thiuram compounds such as thiuram monosulfide, tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrabutylthiuram disulfide, pentamethylenethiuram tetrasulfide; zinc dimethyldithiocarbamate, zinc diethyldithiocarbamate, zinc di-n-butyldithiocarbamate, ethylphenyl Zinc dithiocarbamate, zinc butylphenyl dithiocarbamate, sodium dimethyldithiocarbamate, dimethyl Selenium dithiocarbamate, dithio acid salt-based compounds such as dimethyl dithiocarbamate tellurium; dibutyl Ruki xanthate-based compounds such as Santo Gen zinc; zinc white (zinc oxide) and the like.

  The content of the vulcanization accelerator in the composition is usually 0.1 to 20 parts by weight, preferably 0.2 to 100 parts by weight with respect to 100 parts by weight of the ethylene / α-olefin / non-conjugated polyene random copolymer (A). Although it is a ratio of 10 parts by weight, it is desirable to appropriately determine the optimum amount according to the required physical properties.

  The crosslinking agent contained in the composition of the present invention may be an organic peroxide. Any organic peroxide may be used as long as it is usually used for rubber peroxide vulcanization. Specifically, dicumyl peroxide, di-t-butyl peroxide, di-t-butylperoxy-3,3,5-trimethylcyclohexane, t-butyl hydroperoxide, t-butylcumyl peroxide, benzoyl Peroxide, 2,5-dimethyl-2,5-di (t-butylperoxin) hexyne-3,2,5-dimethyl-2,5-di (benzoylperoxy) hexane, 2,5-dimethyl-2 , 5-mono (t-butylperoxy) -hexane, α, α′-bis (t-butylperoxy-m-isopropyl) benzene, and the like. Of these, dicumyl peroxide, di-t-butyl peroxide, and di-t-butylperoxy-3,3,5-trimethylcyclohexane are preferably used. These organic peroxides are used alone or in combination of two or more.

  The content of the organic peroxide in the composition is usually 0.0003 to 0.05 mol, preferably 0.001 to 0, per 100 g of the ethylene / α-olefin / non-conjugated polyene random copolymer (A). Although it is in the range of 0.03 mol, it is desirable to determine the optimum amount as appropriate according to the required physical properties.

  When using an organic peroxide as a crosslinking agent, it is preferable to use a crosslinking aid in combination. Specific examples of crosslinking aids include sulfur; quinone dioxime compounds such as p-quinone dioxime; methacrylate compounds such as polyethylene glycol dimethacrylate; allyl compounds such as diallyl phthalate and triallyl cyanurate; other maleimides Compound; divinylbenzene and the like are included.

  The content of the crosslinking aid in the composition is 0.5 to 2 mol, preferably about equimolar to 1 mol of the organic peroxide.

[Anti-aging agent]
The composition of the present invention may contain an antiaging agent. If an anti-aging agent is used, it is possible to lengthen the material life of the composition of the present invention and its crosslinked product. This is the same as in the case of ordinary rubber. Examples of the anti-aging agent include those described in JP-A-9-309986. Antiaging agents can be used alone or in combination of two or more. Content of anti-aging agent in a composition is 0.1-5 weight part normally with respect to 100 weight part of copolymers (A), Preferably it is a ratio of 0.5-3 weight part.

[Processing aid]
The composition of the present invention may contain a processing aid. As processing aids, processing aids used in normal rubber processing can be used. Examples of processing aids include those described in [0061] of JP-A-9-309986. The content of the processing aid in the composition is usually about 10 parts by weight or less, preferably about 1 to 5 parts by weight with respect to 100 parts by weight of the copolymer (A).

[Foaming agent and foaming aid]
The composition of the present invention may contain a foaming agent and a foaming aid that are commonly used for rubber. A composition containing a foaming agent and a foaming aid is molded, foamed, and cross-linked (vulcanized) to obtain a cross-linked product made of a foam. Examples of the foaming agent include those described in [0066] of JP-A-9-309986. The foaming agent content in the composition is 0.5 to 30 parts by weight, preferably 1 to 20 parts by weight, based on 100 parts by weight of the ethylene / α-olefin / non-conjugated polyene random copolymer (A). It is.

  You may add a foaming adjuvant to the composition of this invention as needed. The foaming aid used in combination with the foaming agent acts to lower the decomposition temperature of the foaming agent, promote decomposition, and make the bubbles uniform. Examples of foaming aids include those described in JP-A-9-309986. These foaming assistants are 0.01 to 10 parts by weight, preferably 0.1 to 5 parts by weight with respect to 100 parts by weight of the ethylene / α-olefin / non-conjugated polyene random copolymer (A). Although it is possible, it is desirable to appropriately determine the optimum amount according to the required physical property value.

[Defoaming agent]
The composition of the present invention may contain a defoaming agent. When the composition is crosslinked (vulcanized), bubbles may be formed due to the moisture contained therein, and the degree of foaming may be different. Therefore, these are prevented by adding a defoaming agent. The calendar of the defoamer includes calcium oxide.

  The content of the defoaming agent in the composition is usually 20 parts by weight or less, preferably 10 parts by weight or less with respect to 100 parts by weight of the ethylene / α-olefin / non-conjugated polyene random copolymer (A). However, it is desirable to appropriately determine the optimum amount according to the required physical property value.

[Other resins]
The composition of the present invention may contain other resins as long as the object of the present invention is not impaired. Examples of other resins include ethylene / α-olefin copolymer resins. The ethylene / α-olefin copolymer resin is a copolymer resin containing a unit derived from ethylene and a unit derived from an α-olefin having 3 or more carbon atoms, preferably 3 to 20 carbon atoms.

[Composition]
In the composition of the present invention, the content of the polymer (B) is usually 15 to 40 parts by mass with respect to 100 parts by mass of the ethylene / α-olefin / non-conjugated polyene copolymer (A), preferably Is 15 to 35 parts by mass, more preferably 15 to 30 parts by mass, and particularly preferably 15 to 25 parts by mass. The composition of the present invention containing the copolymer (A) and the polymer (B) in a suitable ratio is excellent in processability without excessively increasing the viscosity. Excellent workability means that the composition is easily kneaded.

  Moreover, the composition of this invention containing a copolymer (A) and a polymer (B) in a suitable ratio has high shape memory property of the crosslinked body, and is excellent in rubber elasticity. Shape memory property means that the shape in the state where stress is applied under heating conditions can be easily retained even after cooling to release the stress (shape fixability), and it can easily return to its original shape when reheated. (Shape recovery). “Excellent rubber elasticity” means that the value of permanent compression strain (%) is small.

  In a crosslinked product of a composition containing a low molecular weight component such as the polymer (B) in an elastomer such as the copolymer (A), rubber elasticity or the like may usually be lowered. Surprisingly, however, the composition in which an appropriate amount of the polymer (B) is blended with the copolymer (A) has excellent processability, while the crosslinked product has excellent shape memory property, and A composition that is also excellent in rubber elasticity is obtained. In order to increase the rubber elasticity of the crosslinked product, it is preferable to contain 15 to 25 parts by mass of the polymer (B) per 100 parts by mass of the polymer (A).

  Although the reason why the composition in which an appropriate amount of the polymer (B) is blended with the copolymer (A) is specifically excellent in rubber elasticity is not limited, there is some influence on the influence of the polymer (B) on the crosslinking reaction of the composition. I think that there is a connection. That is, in the composition of the present invention, the polymer (B) is usually dispersed in the copolymer (A) appropriately, and it is considered that the mobility of the copolymer (A) is enhanced.

  Therefore, when the content of the polymer (B) in the composition is small, the fluidity of the composition is lowered, and the mobility of the copolymer (A) during the crosslinking reaction is also lowered. If the mobility of the copolymer (A) during the crosslinking reaction is lowered, it is considered that the crosslinking density of the crosslinked body is reduced and rubber elasticity is hardly exhibited.

  On the other hand, when there is too much content of the polymer (B) in a composition, a polymer (B) cannot be micro-dispersed in a copolymer (A), and will be in an aggregate state. For this reason, it is considered that the rubber elasticity of the crosslinked body is hardly exhibited.

  However, the composition containing 15 to 25 parts by mass of the polymer (B) with respect to 100 parts by mass of the copolymer (A) is a polymer (B) in the copolymer (A). It is considered that the dispersibility is good and the mobility of the copolymer (A) is increased during the crosslinking reaction of the composition, the crosslinking density of the crosslinked body is increased, and a unique phenomenon is exhibited.

  Further, the crosslinked product of the composition of the present invention has higher strength at break in the tensile test than the crosslinked product of the composition containing a high molecular weight polymer instead of the low molecular weight polymer (B), and the elongation at break is also high. high.

[Production Method of Composition]
The composition of the present invention is generally used for the production of rubber products such as ethylene / α-olefin / non-conjugated polyene random copolymer (A) and polymer (B) and, if necessary, a crosslinking agent, a filler, and a softening agent. Various known compounding agents used in the above can be prepared by a general method for producing a rubber compound.

In particular, since the composition of the present invention contains a polymer (B) having a low molecular weight (1 × 10 ³ to 15 × 10 ³ ), the viscosity of the raw material composition at the time of production is relatively small and the load on the kneading apparatus It is easy to manufacture because it is small.

  An example of the manufacturing method of the composition of this invention is shown below. First, the ethylene / α-olefin / non-conjugated polyene copolymer (A) and the polymer (B) are mixed. The mixing may be performed by, for example, a twin screw extruder, a Banbury mixer, a kneader, an internal mixer (closed mixer) such as an intermix, or the like. Thereby, the polymer (B) is dispersed in a molten state in the ethylene / α-olefin / non-conjugated polyene copolymer (A).

  Next, fillers, if necessary, additives such as softeners (for oil expansion), processing aids, vulcanization accelerators, internal mixers such as Banbury mixers, kneaders and intermixes (closed mixers) And kneading at 120 to 250 ° C. (temperature higher than the melting point of the polymer (B)). For example, when the polymer (B) is a polymer containing 50 mol% or more of a structural unit derived from propylene, it is preferably kneaded at 120 to 170 ° C. for 2 to 20 minutes.

  Next, using a roll such as an open roll or a kneader, the kneaded product is sheared at a temperature equal to or higher than the melting point of the polymer (B), and the shearing is applied until the melting point of the polymer (B) or lower is reached. Cool to obtain a blend.

  If necessary, an additive such as a softening agent, a crosslinking agent (vulcanizing agent such as sulfur), a vulcanization accelerator, a foaming agent, a crosslinking agent, or the like, such as an open roll, Mix using a kneader. Furthermore, if necessary, a vulcanization accelerator, a crosslinking aid, a foaming aid, and a desiccant are additionally mixed, kneaded at a roll temperature of 40 to 80 ° C. for 5 to 30 minutes, and then dispensed. A composition can be prepared.

  Since the composition of the present invention uses the low molecular weight polymer (B), the copolymer (A), the polymer (B) and other components are added to the kneading apparatus in any order. The composition can also be manufactured. Furthermore, the copolymer (A), the polymer (B), and other components can be added all at once from the beginning to produce a composition. A mode in which the copolymer (A) and the polymer (B) are previously kneaded to prepare a composition comprising the copolymer (A) and the polymer (B), and other components are added. Is also a preferred embodiment.

  In producing the composition of the present invention, since the polymer (B) is used, the kneading torque during the production is low and the production is easy, and (B) is relatively well dispersed in (A). . The composition of the present invention can be used even in an uncrosslinked state, but when used as a crosslinked product, the effect is well exhibited as shown below.

[Crosslinked product and production method thereof]
The crosslinked product of the present invention is formed by crosslinking (for example, vulcanizing) the composition of the present invention, and is formed by microdispersing the polyolefin resin, and thus has excellent mechanical properties and rubber elasticity. Therefore, it can be applied to various uses including automobile parts, home appliance-related parts, civil engineering / building material-related parts, miscellaneous goods and daily necessities, which are ordinary uses of ethylene / α-olefin / non-conjugated polyene random copolymers.

  Examples of such applications include automotive weather strips, such as door weather strips, trunk weather strips, luggage weather strips, roof side rail weather strips, sliding door weather strips, ventilator weather strips, sliding loop panel weather strips. , Front window weather strip, rear window weather strip, quarter window weather strip, lock pillar weather strip, door glass outer weather strip, door glass inner weather strip, dam windshield, glass run channel, bracket for door mirror, seal headlamp, seal Cowl top; automotive hoses such as brake hoses, radiators Hose, heater hose, air cleaner hose; water supply hose; gas hose; building material seal parts such as gaskets, air tights, joint materials, door stops; home appliance seal parts; automotive cups and seal materials such as master cylinder piston cups And wheel cylinder piston cups.

  The crosslinked product of the present invention (in the case of vulcanization, a rubber molded product) may be a foamed molded product as long as it does not impair physical properties. Specific applications of foam moldings include weather sponges such as door sponges, opening trim sponges, hood seal sponges, trunk seal sponges, etc .; high foam sponge materials such as heat insulation sponges and dam rubbers. Can be mentioned.

The crosslinked product of the present invention is a film, sheet or tube-like heat-shrinkable molded product that may have a pattern such as a texture, in which shape memory properties are particularly required, and various sealing materials, grommets, and clothing. It can be widely used for applications such as gathers, connection of irregularly shaped pipes, and for automotive parts such as joint hoses such as radiator hoses for automobiles, glass run channels, and weatherstrip sponges.
The cross-linked product of the present invention is particularly suitably used for grommets, hoses, sealing materials or automobile weather strips.

[Method for producing crosslinked product]
In order to make the composition of the present invention into a crosslinked product (rubber molded product), after preparing an uncrosslinked (unvulcanized) composition, and then molding the uncrosslinked composition into a desired shape, A crosslinking (vulcanization) reaction may be performed.

  An uncrosslinked (unvulcanized) rubber composition can be molded by various molding methods to crosslink (vulcanize) the composition constituting the molded body. In particular, when molding is performed by molding such as compression molding, extrusion molding, injection molding or the like, and the composition constituting the molded product is crosslinked (vulcanized), the characteristics are easily exhibited.

  In the case of compression molding, an uncrosslinked (unvulcanized) composition weighed in advance is put into a mold, and after closing the mold, it is heated at a temperature of 120 to 270 ° C. for 30 seconds to 120 minutes. A crosslinked product (vulcanized rubber molded product) is obtained.

  In the case of extrusion molding, a ribbon-shaped or pellet-shaped uncrosslinked (unvulcanized) composition is supplied to an extruder in which a die having a desired shape is set. Next, the composition prepared in a desired shape is continuously supplied into a vulcanization tank set at a temperature of 150 ° C. to 350 ° C., and heated for 30 seconds to 20 minutes, whereby the desired crosslinked body is obtained. (Rubber molding) is obtained.

  In the case of injection molding, a ribbon-shaped or pellet-shaped uncrosslinked (unvulcanized) composition is supplied to the pot by a predetermined amount by a screw. Subsequently, the preheated composition is fed into the mold by a plunger in 1 to 20 seconds. After injecting the composition, the target crosslinked product (rubber molded product) is obtained by heating at a temperature of 120 to 270 ° C. for 30 seconds to 120 minutes.

  EXAMPLES Next, although an Example is shown and this invention is demonstrated further in detail, this invention is not limited by these.

  Each physical property of the ethylene / α-olefin / non-conjugated polyene copolymer (A) was measured and evaluated as follows.

(1) Ethylene content: measured by ¹³ CNMR. Specifically, using a JNM-ECX400P nuclear magnetic resonance apparatus manufactured by JEOL, 20 mg of a sample was completely dissolved in about 0.5 ml of deuterated o-dichlorobenzene in an NMR sample tube (5 mmφ), and then 120 The number of integrations was measured at 10,000 ° C. under conditions of 10,000 times or more.
(2) Mooney viscosity (ML): Mooney viscosity at 125 ° C. was measured using a Mooney viscometer (SMV202 type, manufactured by Shimadzu Corporation).
(3) Intrinsic viscosity [η]: About 20 mg of a sample was dissolved in 15 ml of decalin, and the specific viscosity η _sp was measured in an oil bath at 135 ° C. After adding 5 ml of decalin solvent to this decalin solution for dilution, the specific viscosity η _sp is measured in the same manner. This dilution operation was further repeated twice, and the value of η _sp / C when the concentration (C) was extrapolated to 0 was determined as the intrinsic viscosity (see the following formula).
[Η] = lim (η _sp / C) (C → 0)
(4) Iodine value: measured according to JISK0070.

Each physical property of the polymer (B) whose main component is a structural unit derived from one type selected from α-olefins having 3 to 20 carbon atoms was evaluated as follows.
(5) Composition: Measured by ¹³ CNMR. Specifically, the measurement was performed under the same conditions as (1) ethylene content.
(6) Number average molecular weight (Mn): Gel permeation chromatograph Alliance GPC2000 type (Waters) is used, and TSKgel column (manufactured by Tosoh Corp.) × 4 (7.5 mm ID × 30 cm, Tosoh Corp., respectively) ) And o-dichlorobenzene (Wako Pure Chemicals special grade reagent) was used as the mobile phase. The measurement was performed under conditions of a column temperature of 140 ° C. and a mobile phase flow rate of 1.0 mL / min, and a differential refractometer was used for detection. Polystyrene was used for molecular weight calibration.
(7) Melting point: Measured using a differential scanning calorimeter (DSC) [DSC-20 (manufactured by Seiko Electronics Industry)]. First, the measurement sample was once heated to 200 ° C. at a temperature rising rate of 500 ° C./min, held for 5 minutes, and immediately cooled to −20 ° C. at a temperature lowering rate of 20 ° C./min. About 10 mg of this sample was subjected to DSC measurement in the temperature range from −20 ° C. to 200 ° C. under the temperature rising rate of 10 ° C./min. The temperature showing the endothermic peak of the curve obtained from the measurement result in the final temperature raising process was defined as the melting point. When two or more endothermic peaks of the polymer (B) exist, the lowest peak temperature among the temperatures showing the peaks was taken as the melting point.
(8) Density: Measured according to D method (density gradient tube method) of JISK7112.
(9) Penetration (25 degrees): Measured according to the test method described in JISK2207.

Physical properties of the uncrosslinked composition;
(10) Mooney viscosity (ML): Measured by the same method as in (2) above.
(11) Minimum viscosity (Vm) and scorch time (t5): Changes in Mooney viscosity at 125 ° C. were measured using a Mooney viscometer (SMV202 type manufactured by Shimadzu Corporation). Then, the lowest Mooney viscosity after the start of the measurement was defined as the minimum viscosity Vm, and the time required to increase by 5 percent from the minimum viscosity Vm was determined, and this was defined as the scorch time t5 (min.).

Physical properties of the crosslinked product;
(12) Hardness test (HA): The flat part of the vulcanized molded body was overlapped to 12 mm, and the hardness (JIS-A) was measured according to JIS K6253.
(13) Tensile test: The vulcanized molded body was subjected to a tensile test in accordance with JIS K6251 under conditions of a measurement temperature of 23 ° C. and a tensile speed of 500 mm / min to measure strength at break (TB) and elongation at break (EB).
(14) Compression set test: A sample was extracted from the vulcanized molded article in accordance with 6.5 of JIS K6250, and subjected to compression permanent after 70 ° C. × 22 hours and 70 ° C. × 96 hours treatment according to JIS K6262 (1997). Strain was measured.
(15) Shape memory test: A sample was punched from a 2 mm thick sheet into a JIS No. 3 dumbbell shape, a 2 cm marked line (L1) was drawn, and 100% elongation was given (the marked line interval at this time is L2), 200 ° C. Left in oven for 10 minutes. After cooling at room temperature for 30 minutes, the stress was released, and after 30 minutes, the marked line interval (L3) was measured. The shape fixability was calculated by the following formula.
Shape fixability (%) = 100 * (L3-L1) / (L2-L1)
Then, it was again left in a 200 ° C. oven for 10 minutes. After cooling at room temperature for 30 minutes, the stress was released, and after 30 minutes, the marked line interval (L4) was measured. The shape recoverability was calculated by the following formula.
Shape recovery (%) = 100 * (L3-L4) / (L3-L1)

[Production Example 1]
<Production of ethylene / propylene / non-conjugated polyene copolymer (A)>
A quaternary copolymerization reaction of ethylene, propylene, 5-ethylidene-2-norbornene (ENB) and 5-vinyl-2-norbornene (VNB) was continuously performed using a 15 L polymerization vessel equipped with a stirring blade. It was. Hexane was continuously supplied as a polymerization solvent from the upper part of the polymerization vessel at a rate of 5 L / hour, while the polymerization solution was continuously withdrawn from the lower part of the polymerization vessel so that the polymerization solution in the polymerization vessel was always 5 liters. As the catalyst, VOCl ₃ , Al (C ₂ H ₅ ) _1.5 Cl _1.5 was used. That is, VOCl ₃ has a vanadium atom concentration of 0.55 mmol / L in the polymerization vessel, and Al (C ₂ H ₅ ) _1.5 Cl _1.5 has an aluminum atom concentration of 3.3 mmol / L in the polymerization vessel. L was continuously fed into the polymerization vessel.

  Monomer ethylene was continuously fed at a rate of 170 L / h and propylene at a rate of 375 L / h. ENB and VNB were continuously fed so that the concentrations in the polymerization vessel were 7.5 g / L and 0.39 g / L, respectively. Hydrogen was used as the molecular weight regulator, and this was supplied so that the hydrogen concentration in the polymerizer gas phase was 3.1 mol%. The copolymerization reaction was performed at a temperature of 40 ° C. by circulating cooling water through the outer jacket of the polymerization vessel while maintaining the polymerization pressure at 0.7 MPa.

  By such a reaction, a solution in which a copolymer composed of ethylene, propylene, ENB, and VNB was uniformly dissolved was obtained. A small amount of methanol was added to the polymerization solution extracted from the lower part of the polymerization vessel to stop the polymerization reaction. The polymer was separated from the solvent by a steam stripping treatment, and then dried under reduced pressure at 80 ° C. overnight. By the above operation, a copolymer composed of ethylene, propylene, ENB and VNB was obtained at a rate of 265 g per hour.

The physical properties of the obtained ethylene / propylene / non-conjugated polyene copolymer (A) are shown below.
Ethylene content 54.3 wt%, ENB content 8.4 wt%, VNB content 0.4 wt%
ML1 + 4 (125 ° C.) 78
[η] 2.8 dl / g
Iodine number 23.7

[Example 1]
As an ethylene / α-olefin / non-conjugated polyene copolymer (A) component, 100 parts by weight of the copolymer obtained in Production Example 1 was prepared. In addition, as the component (B), a polymer having propylene-derived structural units in a proportion of 50 mol% or more of the total structural units [trade name: High Wax ^TM NP500, manufactured by Mitsui Chemicals, Inc., DSC melting peak temperature 153 / 161 ° C., number average molecular weight (Mn) (7,360), density 905 kg / m ³ , penetration <1 dmm] 20 parts by weight were prepared. The prepared component (A) and component (B) were placed in MIXTRON BB MIXER (Kobe Steel, BB-4, volume 2.95 L, rotor 4WH) and kneaded at about 165 ° C. for 5 minutes. Then, it discharged from the mixer and cooled naturally.

For the obtained composition, 5 parts by weight of zinc white (trade name; META-Z 102, manufactured by Inoue Lime Industry Co., Ltd.) as a vulcanization accelerating aid, 2 parts by weight of stearic acid as a processing aid, active 2 parts by weight of agent (trade name; ARCARD 2HT-F, manufactured by Lion Akzo Co., Ltd.), 90 parts by weight of carbon black (trade name; Asahi # 50G, manufactured by Asahi Carbon Co., Ltd.) as a filler, process as a softener 70 parts by weight of oil (trade name; Diana Process Oil PW-380, manufactured by Idemitsu Kosan Co., Ltd.) was kneaded. The kneading conditions were a rotor rotation speed of 50 rpm, a floating weight pressure of 3 kg / cm ² , and a kneading time of 5 minutes.

  Next, after confirming that the temperature of the blend became 50 ° C., 1 part by weight of sulfur as a vulcanizing agent and “Noxeller MDB-P” (as a vulcanization accelerator) were added to the blend using a 6-inch roll. Product name: 0.5 part by weight of Ouchi Shinsei Chemical Co., Ltd.), 0.5 part by weight of “Noxeller TBT” (trade name: Ouchi Shinsei Chemical Co., Ltd.) as a vulcanization accelerator 1 part by weight of "Sunseller BZ" (trade name; manufactured by Sanshin Chemical Industry Co., Ltd.) as an accelerator, and 1 part by weight of "Sunseller 22-C" (trade name; manufactured by Sanshin Chemical Industry Co., Ltd.) as a vulcanization accelerator 6 parts by weight of “VESTA-BS” (trade name; manufactured by Inoue Lime Industry Co., Ltd.) as a defoaming agent.

  The kneading conditions are as follows: roll temperature is front roll / rear roll = 50 ° C./50° C., roll rotation speed is front roll / rear roll = 13 rpm / 11.5 rpm, roll gap is 2.5 mm, and kneading time is 8 minutes. An uncrosslinked (unvulcanized) composition was obtained. The physical properties of the composition were measured, and the results are shown in Table 1.

  Next, the compound was vulcanized at 170 ° C. for 10 minutes using a press molding machine to prepare a rubber sheet having a thickness of 2 mm. A rubber block for compression set test was prepared by vulcanization at 170 ° C. for 15 minutes. The obtained crosslinked product (vulcanized product) was subjected to a tensile test, a hardness test, a compression set test, and a shape memory test by the above methods. The results are shown in Table 1.

[Example 2]
(B) As a component, a polymer having propylene-derived structural units in a proportion of 50 mol% or more of all structural units [trade name: High Wax ^TM NP505, manufactured by Mitsui Chemicals, Inc., DSC melting peak temperature 143/151 ° C. 20 parts by weight of a number average molecular weight (Mn) (8,430), a density of 903 kg / m ³ , and a penetration hardness <1 dmm] were prepared. (B) Except having changed a component, it obtained the composition and its crosslinked body (vulcanizate) in the same procedure as Example 1, and performed various evaluations. The results are shown in Table 1.

Example 3
(B) As a component, a polymer having a propylene-derived structural unit in a proportion of 50 mol% or more of all structural units [trade name: High Wax ^TM NP506, manufactured by Mitsui Chemicals, Inc., melting peak temperature by DSC 128/138 ° C. 20 parts by weight of a number average molecular weight (Mn) (10,050), a density of 897 kg / m ³ , and a penetration hardness <1 dmm] were prepared. (B) Except having changed a component, in the same procedure as Example 1, the composition and its crosslinked body (vulcanizate) were obtained, and various evaluation was performed. The results are shown in Table 1.

Example 4
(B) As a component, a polymer having propylene-derived constituent units in a proportion of 50 mol% or more of all constituent units [trade name: High Wax ^TM NP055, Mitsui Chemicals, Inc., DSC melting peak temperature 136/145 ° C. , Number average molecular weight (Mn) (3,790), density 900 kg / m ³ , penetration hardness 1 dmm] was prepared in an amount of 20 parts by weight. (B) Except having changed a component, in the same procedure as Example 1, the composition and its crosslinked body (vulcanizate) were obtained, and various evaluation was performed. The results are shown in Table 1.

Example 5
(B) As a component, a polymer having propylene-derived structural units in a proportion of 50 mol% or more of all structural units [trade name: High Wax ^TM NP505, manufactured by Mitsui Chemicals, Inc., DSC melting peak temperature 143/151 ° C. 30 parts by weight of a number average molecular weight (Mn) (8,430), a density of 903 kg / m ³ , and a penetration hardness <1 dmm] were prepared. (B) Except having changed a component, in the same procedure as Example 1, the composition and its crosslinked body (vulcanizate) were obtained, and various evaluation was performed. The results are shown in Table 1.

[Comparative Example 1]
(Ii) Propylene homopolymer (PP) [trade name: Prime Polypro (registered trademark) J105G, manufactured by Prime Polymer Co., Ltd., 230 ° C., 2.16 kg load, instead of the component (B) in Example 1 as high molecular weight polypropylene The MFR measured in step 9.0 was 9.0, and the density was 900 kg / m ³ ]. And (A) component in Example 1 and (ii) component were alloyed with the following method.

  100 parts by weight of component (A) obtained in Production Example 1 and (ii) 20 parts by weight of PP are put into MIXTRON BB MIXER (Kobe Steel Works, BB-4, volume 2.95 L, rotor 4WH). The mixture was kneaded for 5 minutes at a temperature equal to or higher than the melting point of PP (about 170 ° C.), and (ii) PP was uniformly dispersed in component (A). Then, it discharged | emitted from the mixer and prepared the alloy (iii) of (A) component / PP by cooling naturally.

  Except for using the prepared alloy (iii), the composition and its crosslinked product (vulcanized product) were obtained in the same procedure as in Example 1, and various evaluations were performed. The results are shown in Table 1.

[Comparative Example 2]
(B) Polyethylene wax as a component [trade name: EXELEX (registered trademark) 30200B, manufactured by Mitsui Chemicals, Inc., melting point 102 ° C. measured by DSC, number average molecular weight (Mn) 3,960, density 913 kg / m ³ , needle 20 parts by weight were prepared. (B) Except having changed a component, in the same procedure as Example 1, the composition and its crosslinked body (vulcanizate) were obtained, and various evaluation was performed. The results are shown in Table 1.

[Comparative Example 3]
(B) Except not using a component, in the same procedure as Example 1, the composition and its crosslinked body (vulcanizate) were obtained, and various evaluation was performed. The results are shown in Table 1.

[Comparative Example 4]
(B) as propylene homopolymer [trade name: High Wax ^TM NP500, manufactured by Mitsui Chemicals, Inc., melting peak temperature 153/161 ° C. by DSC, number average molecular weight (Mn) 7,360, density 905 kg / m ³ , 10 parts by weight of penetration hardness <1 dmm] and 105 parts by weight of carbon black (trade name; Asahi # 50G, manufactured by Asahi Carbon Co., Ltd.) as a filler were prepared. (B) Except changing the addition amount of a component and a filler, the composition and its crosslinked body (vulcanized material) were obtained in the same procedure as Example 1, and various evaluation was performed. The results are shown in Table 1.

  As can be seen from the comparison between each Example and Comparative Example 3, the crosslinked product of the composition in which the polymer (B) is blended with EPDM is excellent in shape memory property (shape fixability and shape recoverability). Recognize. Further, as can be seen from the comparison between each Example and Comparative Example 2, the crosslinked body of the composition in which the polymer (B) is blended with EPDM is more than the crosslinked body of the composition in which the polyethylene wax is blended with EPDM. It can be seen that the shape memory property (shape fixability and shape recoverability) is excellent.

  As can be seen from the comparison between each Example and Comparative Example 1, the composition (Examples 1 to 5) in which the polymer (B) is blended with EPDM is a composition containing an alloy of EPDM and polypropylene (Comparative Example 1). It can be seen that the viscosity represented by Vm is low, and molding and kneading are easy.

  As can be seen from the comparison between Examples 1 to 3 and Comparative Example 1, the crosslinked product of the composition in which the polymer (B) is blended with EPDM is more permanent than the crosslinked product of the composition containing an alloy of EPDM and polypropylene. It can be seen that the compression strain value (%) is low. Moreover, compared with Examples 1-3, the crosslinked body of the composition of Example 4 has a slightly large value (%) of permanent compression strain, which is related to the molecular weight and melting point of the polymer (B). it is conceivable that.

  Compared with Examples 1 to 4, the value (%) of permanent compression strain of Example 5 is slightly large, but this is considered to be because the blending amount of the polymer (B) is slightly large. Moreover, compared with Examples 1-4, although the shape memory property (shape fixability and shape recovery property) of the comparative example 4 is inferior, it is thought that this is because there are few compounding quantities of a polymer (B).

  The composition of the present invention can provide a crosslinked product having excellent shape memory properties and rubber elasticity. Therefore, the composition of the present invention can be applied to members for various uses including automobile parts, home appliance-related parts, civil engineering / building material-related parts, sundries, and daily necessities.

Claims (12)

100 parts by weight of ethylene / α-olefin / non-conjugated polyene copolymer (A),
15-40 parts by weight of a polymer (B) satisfying the following (i) to (ii) and having as a main component a structural unit derived from one kind selected from α-olefins having 3 to 20 carbon atoms; A composition comprising:
(I) a melting point measured by a differential scanning calorimeter (DSC) of 125 to 245 ° C.,
(Ii) The polystyrene-equivalent number average molecular weight (Mn) measured by gel permeation chromatography (GPC) is 1,000 to 15,000.   The composition according to claim 1, wherein the polymer (B) has a structural unit derived from propylene as a main component.   In the polymer (B), the proportion of the structural unit derived from the α-olefin having 3 to 20 carbon atoms is derived from one selected from the α-olefin having 3 to 20 carbon atoms and the other configuration The composition of Claim 1 or 2 which is 50 mol% or more with respect to a total of 100 mol% with a unit. The composition according to claim 1 or 2, wherein the density of the polymer (B) measured by (iii) density gradient tube method is 820 to 920 kg / m ³ .   Furthermore, the filler is contained, The composition as described in any one of Claims 1-4 characterized by the above-mentioned.   Furthermore, the plasticizer is contained, The composition as described in any one of Claims 1-5 characterized by the above-mentioned.   Furthermore, the crosslinking agent is contained, The composition as described in any one of Claims 1-6 characterized by the above-mentioned.   A crosslinked product obtained by crosslinking the composition according to claim 1. A weather strip for automobiles comprising the crosslinked product according to claim 8. A grommet comprising the cross-linked product according to claim 8. A hose comprising the cross-linked product according to claim 8. The sealing material which consists of a crosslinked body of Claim 8.