JP7189732B2 - Polymer composition and damping material formed from the polymer composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a polymer composition suitable for obtaining a vibration damping material having excellent vibration damping properties, and a vibration damping material comprising the polymer composition.

Traditionally, vibration damping has been applied to the surface and inside of structural members for the purpose of preventing vibration and accompanying noise in structural members such as ships, vehicles, automobile parts, home appliances, various machines, building materials, and audio equipment. , coating or attaching a material having vibration-proof properties has been carried out. As materials having damping and vibration-proofing properties, rubber, asphalt, various synthetic resin emulsions and latexes, synthetic resins, etc., as well as graphite, mica, carbon black, vermiculite, calcium carbonate, and talc have been conventionally used. , powders such as clay, or mixtures of natural or synthetic fibers have been used.

However, many of the above conventional damping materials have damping properties at around room temperature, but the temperature range in which they exhibit damping properties is extremely narrow, and their high density results in an increase in weight (light weight). However, due to poor heat resistance, mechanical properties are extremely reduced at high temperatures, and poor weather resistance limits the range of use.

As a method for improving damping properties, for example, an ethylene/α-olefin/non-conjugated polyene copolymer is added with an α-olefin having 6 to 20 carbon atoms and having a kinematic viscosity of 30 mm ² /s or less at 100°C. Intrinsic viscosity [η] measured in decalin at 135° C. of 0.15 to 0.6 dl/g with at least one polymer and/or hydrogenated product thereof and an ethylene content of 40 to 90 mol % A method of blending an ethylene/α-olefin copolymer (Patent Document 1), wherein at least one peak of loss tangent (tan δ) measured at 100 rad/sec is in the range of -60 to -30 ° C., 0 to 40 ° C. an acrylic copolymer in which an α,β-unsaturated nitrile monomer is copolymerized, and the tan δ peak in the range of -60 to -30 ° C. A rubber composition containing an ethylene/α-olefin copolymer (Patent Document 2), or one or more tan δ peaks determined by dynamic viscoelasticity measurement exist in the temperature range of -50 to -30 ° C. an ethylene/α-olefin/non-conjugated polyene copolymer having one or more tan δ peaks in the temperature range of 0 to 40° C. as determined by dynamic viscoelasticity measurement, a softening agent, A composition containing a reinforcing filler, a vulcanizing agent, and the like has been proposed (Patent Document 3).
However, although such proposed compositions exhibit improved vibration damping properties to some extent, there has been a need to further improve vibration damping properties while maintaining lightness.

JP 2005-029654 A JP 2007-023258 A Retable 2016/143599

SUMMARY OF THE INVENTION An object of the present invention is to provide a composition for a vibration damping material which is lightweight and has very high vibration damping properties.

In the present invention, a polymer (B) having a loss tangent tan δ peak determined by dynamic viscoelasticity measurement in a temperature range of −60° C. or more and less than 0° C., 100 parts by mass of the polymer (B), 50 to 500 parts by mass of an olefin copolymer (A) having a loss tangent tan δ peak in the temperature range of 0° C. or higher and 60° C. or lower, and an average fiber length of 0.1 mm or more and 12 mm. It relates to a polymer composition characterized by containing 0.5 to 100 parts by mass of organic short fibers (C) in the following range.

The polymer composition of the present invention is intended to provide a composition for vibration damping materials that is lightweight and has very high vibration damping properties.

<Polymer (B)>
The polymer (B), which is one of the components constituting the polymer composition of the present invention, preferably has a loss tangent tan δ peak of -60 to 0 ° C., more preferably - The polymer (B) has a temperature range of 55 to -5°C, particularly preferably -50 to -10°C.

The tan δ obtained by dynamic viscoelasticity measurement of the polymer (B) according to the present invention and the olefinic copolymer (A) described below will be described. A sample composed of a polymer or copolymer is subjected to dynamic viscoelasticity measurement while continuously changing the ambient temperature, and the storage elastic modulus G' and the loss elastic modulus G'' are measured and given as G''/G'. Determine the loss tangent tan δ. Looking at the relationship between temperature and loss tangent tan δ, loss tangent tan δ generally has a peak at a specific temperature. The temperature at which the peak appears is generally called the glass transition temperature (hereinafter also referred to as tan δ-Tg). The temperature at which the loss tangent tan δ peak appears can be obtained based on the dynamic viscoelasticity measurement described in Examples.

When a polymer has a plurality of tan δ peaks, the polymer (B) of the present invention is defined as a polymer having a maximum intensity peak within the above temperature range.
The type of the polymer (B) according to the present invention is not particularly limited as long as it is a polymer having a loss tangent tan δ peak in the range of -60 to 0°C as determined by dynamic viscoelasticity measurement.

Specific examples of the polymer (B) according to the present invention include ethylene rubber, diene rubber, chloroprene rubber (CR), acrylic rubber (ACM), ethylene acrylic rubber (AEM), silicone rubber (Q ), epichlorohydrin rubber (CO, ECO), urethane rubber (Q), chlorosulfonated polyethylene (CSM), and the like, or polymers called elastomers.

Examples of the diene rubber include isoprene rubber (IR), natural rubber (NR), butadiene rubber (BR), styrene butadiene rubber (SBR), nitrile rubber (NBR), hydrogenated nitrile rubber (HNBR), and butyl rubber. (IIR) and the like.

Among these polymers (B), ethylene-based rubbers such as ethylene/α-olefin copolymer (B-1) and ethylene/α-olefin/non-conjugated polyene copolymer (B-2) are preferred.

<<Ethylene/α-olefin copolymer (B-1)>>
Examples of the ethylene/α-olefin copolymer (B-1) according to the present invention include copolymers of ethylene and an α-olefin having 3 to 20 carbon atoms. Examples of α-olefins include 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-eicosene-1, 9-methyl-1-decene, 11-methyl-1-dodecene, 12-ethyl- 1-tetradecene and the like. These α-olefins can be used alone or in combination of two or more.

<<Ethylene/α-olefin/non-conjugated polyene copolymer (B-2)>>
The α-olefin in the ethylene/α-olefin/nonconjugated polyene copolymer (B-2) according to the present invention is the same as the α-olefin in the ethylene/α-olefin copolymer (B-1). .

The non-conjugated polyene in the ethylene/α-olefin/non-conjugated polyene copolymer (B-2) according to the present invention has, for example, 5 to 20 carbon atoms, preferably 5 to 10 carbon atoms, 1,4- Pentadiene, 1,4-hexadiene, 1,5-hexadiene, 1,4-octadiene, 1,5-octadiene, 1,6-octadiene, 1,7-octadiene, 2-methyl-1,5-hexadiene, 6- methyl-1,5-heptadiene, 7-methyl-1,6-octadiene, 4-ethylidene-8-methyl-1,7-nonadiene, 4,8-dimethyl-1,4,8-decatriene, dicyclopentadiene, Cyclohexadiene, dicyclooctadiene, methylenenorbornene, 5-vinylnorbornene, 5-ethylidene-2-norbornene, 5-methylene-2-norbornene, 5-vinylidene-2-norbornene, 5-isopropylidene-2-norbornene, 6 -chloromethyl-5-isopropenyl-2-norbornene, 2,3-diisopropylidene-5-norbornene, 2-ethylidene-3-isopropylidene-5-norbornene, 2-propenyl-2,2-norbornadiene, etc. be able to.

The polymer (B) according to the present invention preferably contains an ethylene/α-olefin/non-conjugated polyene copolymer in terms of heat aging resistance, weather resistance and ozone resistance. The content of the ethylene/α-olefin/non-conjugated polyene copolymer in the polymer (B) is preferably 50 to 100% by mass, more preferably 70 to 100% by mass.

In the ethylene/α-olefin/non-conjugated polyene copolymer (B-2) according to the present invention, from the viewpoint of flexibility, the content of structural units derived from ethylene is preferably 40 to 72% by mass, more preferably 42 to 66% by mass, more preferably 44 to 62% by mass, and the content of structural units derived from non-conjugated polyene is preferably 2 to 15% by mass, more preferably 5 to 14% by mass, further preferably 7 ~12% by mass.

In the ethylene/α-olefin/non-conjugated polyene copolymer (B-2) according to the present invention, among the above-mentioned α-olefins, α-olefins having 3 to 10 carbon atoms are preferred, particularly propylene, 1-butene, 1-hexene, 1-octene and the like are particularly preferred.

In the ethylene/α-olefin/nonconjugated polyene copolymer (B-2) according to the present invention, preferred nonconjugated polyenes among the above nonconjugated polyenes include dicyclopentadiene, 5-vinylidene-2-norbornene, 5-ethylidene-2-norbornene and the like.
When the polymer (B) according to the present invention contains crystallized polyolefin, its content is preferably less than 10% by mass.

<Olefin-based copolymer (A)>
The olefin copolymer (A), which is one of the components constituting the polymer composition of the present invention, has a loss tangent tan δ peak determined by dynamic viscoelasticity measurement in a temperature range of 0 ° C. to 60 ° C. It is preferably a copolymer present in the range of 5°C to 50°C, more preferably 10°C to 40°C.

When a copolymer has a plurality of tan δ peaks, the polymer having the maximum intensity peak within the above temperature range is defined as the olefin copolymer (A) of the present invention.
The intrinsic viscosity [η] of the olefinic copolymer (A) according to the present invention is preferably in the range of 0.5 to 5.0 dL/g, more preferably 0.6 to 4, from the viewpoint of workability. 0 dL/g, particularly preferably 0.7 to 3.5 dL/g.

Although the method for adjusting the intrinsic viscosity [η] is not particularly limited, the intrinsic viscosity [η] can be adjusted by adjusting the molecular weight of the polymer by using hydrogen molecules during polymerization.
The olefin copolymer (A) according to the present invention has a molecular weight distribution (Mw/Mn), which is the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn). From the viewpoint of workability, it is preferably 1.0 to 3.5, more preferably 1.2 to 3.0, and particularly preferably 1.5 to 2.5.

The olefinic copolymer (A) according to the present invention may be of a single type or may be used in combination of multiple types.
The olefinic copolymer (A) according to the present invention preferably contains a 4-methyl-1-pentene/α-olefin copolymer (A-1) from the viewpoint of weather resistance and ozone resistance.

<<4-methyl-1-pentene/α-olefin copolymer (A-1)>>
The α-olefin in the 4-methyl-1-pentene/α-olefin copolymer (A-1) according to the present invention is, for example, an α-olefin having 2 to 20 carbon atoms, and 4-methyl-1-pentene Except for, linear or branched α-olefins, cyclic olefins, aromatic vinyl compounds, conjugated dienes, functionalized vinyl compounds, hydroxyl group-containing olefins, halogenated olefins, and the like can be mentioned.

The linear α-olefin has 2 to 20 carbon atoms, preferably 2 to 15 carbon atoms, more preferably 2 to 10 carbon atoms, and includes ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1- Octene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene and the like, preferably ethylene, propylene, 1-butene, 1-pentene, 1- Hexene, 1-octene.

The branched α-olefin preferably has 5 to 20 carbon atoms, more preferably 5 to 15 carbon atoms, and includes 3-methyl-1-butene, 3-methyl-1-pentene and 3-ethyl-1-pentene. , 4,4-dimethyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene, 4-ethyl-1-hexene, 3-ethyl-1-hexene and the like.

The cyclic olefins have 3 to 20 carbon atoms, preferably 5 to 15 carbon atoms, and include cyclopentene, cyclohexene, cycloheptene, norbornene, 5-methyl-2-norbornene, tetracyclododecene and vinylcyclohexane.

Examples of aromatic vinyl compounds include styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, o,p-dimethylstyrene, o-ethylstyrene, m-ethylstyrene, p-ethylstyrene. mono- or polyalkylstyrenes such as

The conjugated diene has 4 to 20 carbon atoms, preferably 4 to 10 carbon atoms, and includes 1,3-butadiene, isoprene, chloroprene, 1,3-pentadiene, 2,3-dimethylbutadiene, 4-methyl-1,3 -pentadiene, 1,3-hexadiene, 1,3-octadiene and the like.

Functionalized vinyl compounds include hydroxyl group-containing olefins, halogenated olefins, (meth)acrylic acid, propionic acid, 3-butenoic acid, 4-pentenoic acid, 5-hexenoic acid, 6-heptenoic acid, 7-octenoic acid, Unsaturated carboxylic acids such as 8-nonenoic acid, 9-decenoic acid and 10-undecenoic acid, unsaturated amines such as allylamine, 5-hexeneamine and 6-heptenamine, (2,7-octadienyl)succinic anhydride, penta Unsaturated carboxylic acid anhydrides such as propenylsuccinic anhydride, anhydrides obtained from the above unsaturated carboxylic acids, unsaturated carboxylic acid halides such as halides obtained from the above unsaturated carboxylic acids, 4-epoxy-1 -butene, 5-epoxy-1-pentene, 6-epoxy-1-hexene, 7-epoxy-1-heptene, 8-epoxy-1-octene, 9-epoxy-1-nonene, 10-epoxy-1-decene , 11-epoxy-1-undecene and other unsaturated epoxy compounds, vinyltriethoxysilane, vinyltrimethoxysilane, 3-acroxypropyltrimethoxysilane, γ-glycidoxypropyltripyltrimethoxysilane, γ-aminopropyl Examples include ethylenically unsaturated silane compounds such as triethoxysilane and γ-methacryloxypropyltrimethoxysilane.

The hydroxyl-containing olefin is not particularly limited as long as it is an olefin-based compound containing a hydroxyl group, and examples thereof include hydroxyl-terminated olefin-based compounds. Examples of hydroxyl-terminated olefin compounds include vinyl alcohol, allyl alcohol, hydroxylated-1-butene, hydroxylated-1-pentene, hydroxylated-1-hexene, hydroxylated-1-octene, hydroxylated-1-decene, 2 to 20 carbon atoms such as 1-undecene hydroxide, 1-dodecene hydroxide, 1-tetradecene hydroxide, 1-hexadecene hydroxide, 1-octadecene hydroxide, and 1-eicosene hydroxide; preferably 2 to 15 linear hydroxylated -α-olefins, hydroxylated -3-methyl-1-butene, hydroxylated -3-methyl-1-pentene, hydroxylated -4-methyl-1-pentene, -3-ethyl-1-pentene hydroxide, -4,4-dimethyl-1-pentene hydroxide, -4-methyl-1-hexene hydroxide, -4,4-dimethyl-1-hexene hydroxide, -4,4-dimethyl-1-hexene hydroxide, -4-ethyl-1-hexene, hydroxylated -3-ethyl-1-hexene, preferably branched hydroxylated α-olefins having 5 to 20 carbon atoms, more preferably 5 to 15 carbon atoms. .

Examples of the halogenated olefins include halogenated α-olefins having Group 17 atoms of the periodic table such as chlorine, bromine, and iodine. -1-pentene, -1-hexene halide, -1-octene halide, -1-decene halide, -1-dodecene halide, -1-undecene halide, -1-tetradecene halide, -1-halide - 1-hexadecene, halogenated 1-octadecene, halogenated 1-eicosene, etc. having 2 to 20 carbon atoms, preferably 2 to 15 linear halogenated α-olefins, halogenated 3-methyl -1-butene, Halide-4-methyl-1-pentene, Halide-3-methyl-1-pentene, Halide-3-ethyl-1-pentene, Halide-4,4-dimethyl-1-pentene , Halogenated-4-methyl-1-hexene, Halogenated-4,4-dimethyl-1-hexene, Halogenated-4-ethyl-1-hexene, Halogenated-3-ethyl-1-hexene etc. Preferably Examples include branched halogenated α-olefins having 5 to 20 carbon atoms, more preferably 5 to 15 carbon atoms.

The α-olefin in the 4-methyl-1-pentene/α-olefin copolymer (A-1) may be of one type alone or in combination of two or more types.
The α-olefin in the 4-methyl-1-pentene/α-olefin copolymer (A-1) is particularly ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 3-methyl-1- butene, 3-methyl-1-pentene, 1-octene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, norbornene, 5-methyl-2- Norbornene, tetracyclododecene, and 1-undecene hydroxide are preferred. Furthermore, from the viewpoint of flexibility, light weight, damping property, etc., linear α-olefins having 2 to 10 carbon atoms are preferable, and ethylene, propylene, 1-butene, 1-pentene, 1-hexene and 1-octene is more preferred, ethylene and propylene are preferred, and propylene is particularly preferred.

The 4-methyl-1-pentene/α-olefin copolymer (A-1) according to the present invention may have structural units derived from non-conjugated polyene, if necessary. Examples of non-conjugated polyenes include 1,4-pentadiene, 1,4-hexadiene, 1,5-hexadiene, 1,4-octadiene, 1, 5-octadiene, 1,6-octadiene, 1,7-octadiene, 2-methyl-1,5-hexadiene, 6-methyl-1,5-heptadiene, 7-methyl-1,6-octadiene, 4-ethylidene- 8-methyl-1,7-nonadiene, 4,8-dimethyl-1,4,8-decatriene, dicyclopentadiene, cyclohexadiene, dicyclooctadiene, methylenenorbornene, 5-vinylnorbornene, 5-ethylidene-2- norbornene, 5-methylene-2-norbornene, 5-vinylidene-2-norbornene, 5-isopropylidene-2-norbornene, 6-chloromethyl-5-isopropenyl-2-norbornene, 2,3-diisopropylidene-5 -norbornene, 2-ethylidene-3-isopropylidene-5-norbornene, 2-propenyl-2,2-norbornadiene and the like.

The 4-methyl-1-pentene/α-olefin copolymer (A-1) according to the present invention may contain other copolymer components as long as the object of the present invention is not impaired.
As the 4-methyl-1-pentene/α-olefin copolymer (A-1) according to the present invention, the structural unit (i) derived from 4-methyl-1-pentene, 4-methyl-1-pentene 4-methyl- having a structural unit (ii) derived from at least one α-olefin selected from α-olefins having 2 to 20 carbon atoms excluding (ii) and a structural unit (iii) optionally derived from a non-conjugated polyene A 1-pentene/α-olefin copolymer is preferred. The content ratio of the structural unit (i), the structural unit (ii) and the structural unit (iii) is preferably the structural unit (i ) 16 to 95 mol%, structural unit (ii) 5 to 84 mol%, structural unit (iii) 0 to 10 mol%, more preferably structural unit (i) 26 to 90 mol%, structural unit (ii) 10 to 74 mol%, structural unit (iii) 0 to 7 mol%, more preferably structural unit (i) 61 to 85 mol%, structural unit (ii) 15 to 39 mol%, structural unit (iii) 0 ~5 mol%.

The 4-methyl-1-pentene/α-olefin copolymer (A-1) according to the present invention has a content ratio of the structural unit (i) of 16 to 95 mol% and a content ratio of the structural unit (ii) of 5 to 84 mol%, and the content ratio of the structural unit (iii) is in the range of 0 to 10 mol% (where the total of the structural units (i), (ii) and (iii) is 100 mol%). preferable.

<Organic staple fiber (C)>
The short organic fibers (C) constituting the polymer composition of the present invention are not particularly limited as long as they are fibrous organic materials having an average fiber length in the range of 0.1 to 12 mm. For the average fiber length of the organic short fibers (C), for example, a photograph is taken with an optical microscope, the length of 100 randomly selected short fibers in the obtained photograph is measured, and the arithmetic mean is can be obtained by If the average fiber length is too short, the damping properties may be insufficient. On the other hand, if the average fiber length is too long, the processability of the polymer composition during kneading may deteriorate. The average fiber length of the organic short fibers (C) is preferably 0.3-10 mm, more preferably 0.5-6 mm.

The average fiber diameter of the organic short fibers (C) is not particularly limited, but is preferably 0.5 to 100 μm, more preferably 1 to 50 μm, and still more preferably 2 to 20 μm. For the average fiber diameter of the organic short fibers (b), for example, photographs are taken with an optical microscope, and the diameter (diameter) of the thickest portion of 100 randomly selected short fibers in the obtained photograph is measured. can be obtained by arithmetically averaging them. In addition, the aspect ratio of the organic short fibers (b) (“average fiber length of organic short fibers”/“average fiber diameter of organic short fibers”) is not particularly limited, but is preferably 5 to 1000, more preferably 50 to 800.

Organic staple fibers (C) according to the present invention include natural fibers such as cotton and wood cellulose fibers; polyamide, polyester, polyvinyl alcohol, rayon, polyparaphenylenebenzobisoxazole, polyethylene, polypropylene, polyarylate, polyimide, and polyphenylene sulfide. , polyether ether ketone, polylactic acid, polycaprolactone, polybutylene succinate, fibers made of synthetic resins such as fluorine-based polymers; Among these, short fibers made of synthetic resin are preferably used, and short fibers made of polyamide are more preferably used, since the effect of the present invention becomes more remarkable.

Polyamides include polycapramide, poly-ω-aminoheptanoic acid, poly-ω-aminononanoic acid, polyundecaneamide, polyethylenediamineadipamide, polytetramethyleneadipamide, polyhexamethyleneadipamide, polyhexamethylenesebaka aliphatic polyamides such as polyhexamethylenedodecamide, polyoctamethyleneadipamide, polydecamethyleneadipamide; (trade name "Twaron", manufactured by Teijin Ltd.), etc.), polymetaphenylene isophthalamide (e.g., (trade name "Conex", manufactured by Teijin Ltd.), etc.), copolyparaphenylene 3 , 4' oxydiphenylene terephthalamide (for example, (trade name "Technora", manufactured by Teijin Limited), etc.), polymetaxylylene adipamide, polymetaxylylenepimeramide, polymetaxylylene azelamide, polypara aromatic polyamides (aramids) such as xylyleneazelamide and polyparaxylylenedecanamide; Among these, aromatic polyamides, i.e., aramids, are preferable because they can further improve damping properties, and polyparaphenylene terephthalamide, polymetaphenylene isophthalamide and copolyparaphenylene 3, 4'-oxydiphenylene-terephthalamide is more preferred, and copoly-paraphenylene-3,4'-oxydiphenylene-terephthalamide is particularly preferred.

That is, as short fibers made of polyamide, aramid short fibers are preferable, and polyparaphenylene terephthalamide short fibers, polymetaphenylene isophthalamide short fibers and copolyparaphenylene/3,4'oxydiphenylene/terephthalamide short fibers are preferred. More preferred are copolyparaphenylene/3,4'oxydiphenylene/terephthalamide short fibers.

The organic short fibers (C) may be in the form of chopped fibers (cut fibers) or fibril-containing pulp. It may be one subjected to various treatments.

<Polymer composition>
The polymer composition of the present invention contains 25 to 500 parts by mass, preferably 50 to 400 parts by mass, of the olefin copolymer (A) per 100 parts by mass of the polymer (B). 100 to 300 parts by mass, preferably 0.5 to 100 parts by mass, preferably 1 to 60 parts by mass, and more preferably 3 to 30 parts by mass of the organic short fibers (C).

The polymer composition of the present invention contains the polymer (B), the olefin copolymer (A) and the organic short fibers (C) in the above range, so that it is lightweight and has extremely high damping properties. You can get vibration material.
The polymer composition of the present invention preferably contains a softening agent in addition to the polymer (B), olefinic copolymer (A) and organic short fibers (C).

《Softener》
The softening agent according to the present invention can be appropriately selected according to its use, and may be used singly or in combination of multiple kinds. Specific examples of softening agents include process oils such as paraffin oil (for example, "Diana Process Oil PS-430" (trade name: manufactured by Idemitsu Kosan Co., Ltd.), etc.), lubricating oils, liquid paraffin, petroleum asphalt, petroleum jelly, and the like. Coal tar softeners such as coal tar and coal tar pitch; Fatty oil softeners such as castor oil, linseed oil, rapeseed oil, soybean oil, and coconut oil; beeswax, carnauba wax, and Waxes such as lanolin; fatty acids such as ricinoleic acid, palmitic acid, stearic acid, barium stearate, calcium stearate, and zinc laurate, or salts thereof; naphthenic acid, pine oil, and rosin or derivatives thereof; terpene resins, petroleum resins , atactic polypropylene, and coumarone-indene resin; ester-based softeners such as dioctyl phthalate, dioctyl adipate, and dioctyl sebacate; Hydrocarbon-based synthetic lubricating oils, tall oil, sub (factice), and the like. Among these, petroleum-based softening agents are preferred, and process oils, particularly paraffin oil, are preferred.

When the polymer composition of the present invention contains a softening agent, the blending amount thereof is 5 to 500 parts by mass, preferably 10 to 400 parts by mass, more preferably 15 parts by mass with respect to 100 parts by mass of the polymer (B). ~300 parts by mass.

By setting the blending amount of the softening agent contained in the polymer composition within the above range, the damping properties of the resulting damping material can be further improved. If the amount of the softening agent is too small, the effect of improving the damping property may become small. On the other hand, if the softening agent is too much, there is a possibility that workability and stain resistance may deteriorate.

《Crosslinking agent (vulcanizing agent)》
In addition to the polymer (B), the olefinic copolymer (A) and the organic short fibers (C), it is preferable to contain a cross-linking agent (vulcanizing agent). Sulfur, sulfur compounds, organic peroxides, phenolic resins, oxime compounds and the like can be used as the cross-linking agent (vulcanizing agent).

Examples of sulfur compounds include sulfur chloride, sulfur dichloride, morpholine disulfide, alkylphenol disulfide, tetramethylthiuram disulfide, and selenium dithiocarbamate. Among sulfur and sulfur-based compounds, sulfur and tetramethylthiuram disulfide are preferred.

Examples of the organic peroxide include dicumyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, 2, Examples include 5-diethyl-2,5-di(t-butylperoxy)hexyne-3, di-t-butylperoxide, di-t-butylperoxy-3,3,5-trimethylcyclohexane, t-dibutylhydroperoxide and the like. can.

The content of the cross-linking agent (vulcanizing agent) is 0.1 to 10 parts by mass, preferably 0.3 to 9.0 parts by mass, more preferably 0, per 100 parts by mass of the polymer (B). .5 to 8.0 parts by mass.

When the polymer composition of the present invention contains a sulfur-based compound as a cross-linking agent (vulcanizing agent), a vulcanization accelerator is preferably used in combination. Vulcanization accelerators include N-cyclohexyl-2-benzothiazolesulfenamide, N-oxydiethylene-2-benzothiazolesulfenamide, N,N'-diisopropyl-2-benzothiazolesulfenamide, 2-mercapto Benzothiazole (e.g., "Sancellar M" (trade name: manufactured by Sanshin Chemical Industry Co., Ltd.), etc.), 2-(4-morpholinodithio) benzothiazole (e.g., "Noccellar MDB-P" (trade name: Sanshin Chemical Industry Co., Ltd.), 2-(2,4-dinitrophenyl)mercaptobenzothiazole, 2-(2,6-diethyl-4-morpholinothio)benzothiazole, thiazoles such as dibenzothiazyl disulfide; Guanidines such as diphenylguanidine, triphenylguanidine and diorthotolylguanidine; acetaldehyde-aniline condensates, butyraldehyde-aniline condensates, aldehyde amines; imidazolines such as 2-mercaptoimidazoline; thioureas such as diethylthiourea and dibutylthiourea Thiuram system such as tetramethylthiuram monosulfide and tetramethylthiuram disulfide; zinc dimethyldithiocarbamate, zinc diethyldithiocarbamate, zinc dibutyldithiocarbamate (e.g., "Sancellar PZ" (trade name: manufactured by Sanshin Chemical Industry Co., Ltd.) , "Suncellar BZ" (product name: manufactured by Sanshin Chemical Industry Co., Ltd.), etc.), dithioate salts such as tellurium diethyldithiocarbamate; ), "Suncellar 22-C" (product name: manufactured by Sanshin Chemical Industry Co., Ltd.), etc.), thiourea-based such as N,N'-diethylthiourea; xanthate-based such as zinc dibutylxathate; zinc oxide (zinc white), activated zinc white, and the like.

The content of these vulcanization accelerators is 0.1 to 20 parts by mass, preferably 0.2 to 15 parts by mass, more preferably 0.5 to 10 parts by mass, relative to 100 parts by mass of the polymer (B). Department.
Furthermore, a cross-linking aid (vulcanization aid) can be contained. Specific examples of cross-linking aids (vulcanization aids) include magnesium oxide, zinc oxide (zinc white), active zinc white, quinonedioxime systems such as p-quinonedioxime; ethylene glycol dimethacrylate, trimethylolpropane acrylics such as trimethacrylate; allyls such as diallyl phthalate and triallyl isocyanurate; other maleimides; and divinylbenzene. The cross-linking aids (vulcanization aids) may be used alone or in combination of two or more. The content of the vulcanization aid is usually 1 to 20 parts by mass with respect to 100 parts by mass of polymer (B).

《Reinforcement》
The polymer composition of the invention may further contain reinforcing agents and/or fillers.
Carbon black, silica, etc. are mentioned as a reinforcing material related to the present invention.
Carbon black includes SAF-HS, SAF, ISAF-HS, ISAF, ISAF-LS, I-ISAF-HS, HAF-HS, HAF, HAF-LS, T-HS, T-NS, MAF, FEF, FEF Furnace blacks such as -HS, GPF, SRF-HS-HM, SRF-LM and ECF, thermal blacks such as FT and MT, acetylene black, channel black and Austin black. Further, these carbon blacks may be surface-treated with a silane coupling agent or the like.

Examples of silica include natural silica such as quartz powder and silica powder; synthetic silica such as silicic anhydride (silica gel, aerosil, etc.) and hydrous silicic acid; among others, synthetic silica is preferred. Further, these silicas may be surface-treated with a coupling agent or the like.

Fillers include light calcium carbonate, heavy calcium carbonate, talc, clay, mica, zeolite, kaolinite, smectite, montmorillonite, sericite, illite, glauconite, chlorite, organic bentonite (montmorillonite and quaternary ammonium Hydrophobic compounds surface-treated with organic cations such as salts), diatomaceous earth, aluminum hydroxide, aluminum sulfate, barium sulfate, calcium sulfate, magnesium oxide, titanium oxide, aluminum silicate, molybdenum disulfide, graphite, ebonite powder, wood flour , cork powder, cellulose powder, metal powder, resin powder, and glass powder.

When the polymer composition of the present invention contains a reinforcing material or the like, the amount thereof is usually 10 to 500 parts by mass, preferably 20 to 400 parts by mass, particularly 100 parts by mass of the polymer (B). It is preferably 30 to 300 parts by mass. Reinforcing materials and the like may be used singly or in combination.

《Processing aid》
The polymer composition of the present invention may further contain processing aids. Processing aids according to the present invention include ricinoleic acid, stearic acid, palmitic acid, lauric acid, barium stearate, zinc stearate, calcium stearate or esters.

When the polymer composition of the present invention contains a processing aid, the amount thereof is 20 parts by mass or less, preferably 15 parts by mass or less, more preferably 10 parts by mass with respect to 100 parts by mass of the polymer (B). It can be appropriately blended in an amount of 1 part or less.

In addition to the above, the polymer composition of the present invention may contain an activator, a cross-linking retarder, a moisture absorber, an antioxidant, a tackifier, an antifungal agent, a lubricant, and a flame retardant within a range that does not impair the effects of the present invention. , an acid acceptor, a silane coupling agent, an antistatic agent, a foaming agent, a magnetic powder, a resin, and the like. These compounding agents can be appropriately employed in amounts depending on the purpose of compounding.

The polymer composition of the present invention can be obtained by mixing the above components. Although the method for preparing the polymer composition according to the present invention is not particularly limited, it is kneaded with an internal kneader such as a Banbury mixer, an intermixer, or a kneader, an extruder such as a single-screw extruder or a twin-screw extruder, or an open roll. You can adjust by doing In the kneading, a single device may be used, or plural kinds of devices may be used in combination.

<Method for Producing Crosslinked Polymer Composition>
When producing a damping material using the polymer composition of the present invention, the polymer composition may be crosslinked.

The crosslinked product of the polymer composition of the present invention can be obtained by using the polymer composition of the present invention and molding machines corresponding to desired shapes, such as extruders, injection molding machines, press molding machines, rolls, and calender molding. It can be manufactured by molding with a machine or the like, performing a cross-linking reaction by heating, and fixing the shape as a cross-linked product. In this case, the cross-linking may be performed after pre-molding, or the cross-linking may be performed at the same time as the molding. The molding temperature is usually 10-200°C, preferably 25-120°C. The crosslinking temperature is usually 100 to 200°C, preferably 130 to 190°C, and the crosslinking time is usually 1 minute to 24 hours, preferably 2 minutes to 12 hours, particularly preferably 3 minutes to 6 hours. .

Further, depending on the shape, size, etc. of the crosslinked product, even if the surface is crosslinked, the inside may not be sufficiently crosslinked. Therefore, secondary crosslinking may be performed by further heating.
As the cross-linking method, general methods used for cross-linking rubber such as press cross-linking, steam cross-linking and oven cross-linking can be appropriately selected.

<Method for manufacturing damping material>
The damping material of the present invention is formed from the above polymer composition. Moreover, the vibration damping material formed from the polymer composition of the present invention may be obtained by cross-linking the polymer composition. The damping material of the present invention is preferably in the form of a sheet. Since it is in the form of a sheet, it can be used by attaching it to an object to be vibrated (various parts, housing, etc.) by, for example, pressure bonding, thermocompression bonding (baking), or adhesion using an adhesive or the like.
The sheet-like damping material has a thickness of 0.1 to 10.0 mm, preferably 0.2 to 7.5 mm, particularly preferably 0.3 to 5.0 mm.

The damping material using the polymer composition of the present invention can be formed into a sheet by various known production methods. Specifically, for example, a method of forming the copolymer composition into a sheet of a desired thickness by press molding, calender molding, or extrusion molding, or kneading the polymer composition with an open roll and then adjusting the thickness. A method of forming a sheet of a desired thickness by dispensing and kneading using an extruder such as a single-screw extruder or a twin-screw extruder to obtain the desired thickness by extrusion while obtaining a polymer composition and the like. In the vibration damping material using the polymer composition of the present invention, when the polymer composition is crosslinked, it is formed into a sheet shape in the various production methods described above and simultaneously crosslinked, or is formed into a sheet shape in advance in the various production methods described above. A method of cross-linking later may be mentioned.

<Damping material>
The vibration damping material using the polymer composition of the present invention can also be used as a constrained vibration damping material in which a layer made of the polymer composition or a crosslinked product of the polymer composition and a constraining layer are laminated. can.

The layer composed of the copolymer composition constituting the constrained vibration damping material preferably has a thickness of 0.1 mm to 6.0 mm, more preferably 0.5 mm to 3.0 mm, particularly preferably 1.0 mm to 6.0 mm. It is in the range of 2.0 mm.

Examples of the constraining layer constituting the constraining damping material include metal foil, metal mesh, resin, fiber-reinforced resin, and glass cloth.
The constraining layer constituting the damping material of the present invention preferably has a thickness in the range of 0.05 to 10.0 mm, more preferably 0.08 to 5.0 mm.

《Uses of damping materials》
The damping material using the polymer composition of the present invention is attached to various parts and housings to be vibrated, or sandwiched between various parts and housings to be vibrated. , damping the housing.
The vibration damping material of the present invention uses the polymer composition within the range described above, so that it is lightweight and has extremely excellent vibration damping properties.

For this reason, the damping material of the present invention can be used in various vibration-generating applications such as automobiles, ships, railroad vehicles, aircraft, household appliances, OA equipment, AV equipment, office equipment, construction, housing equipment, machine tools, and industrial machinery. Can be used for any purpose.

EXAMPLES The present invention will be described in more detail below based on examples, but the present invention is not limited to these examples. In the following, "parts" are based on mass unless otherwise specified.

(Measurement method and evaluation method)
In the following examples and comparative examples, physical properties and the like were measured and evaluated by the following methods.
[composition]
The contents (mol %) of 4-methyl-1-pentene and α-olefin in the olefinic copolymer (A) were determined by ¹³ C-NMR. Measured by ¹³ C-NMR. The measured value was obtained using an ECP500 type nuclear magnetic resonance apparatus (manufactured by JEOL Ltd.) at a measurement temperature of 120°C, a measurement solvent of ortho-dichlorobenzene, and a cumulative number of times of 10,000 or more. - Obtained by measuring the spectrum of NMR.

The weight fraction (% by weight) of each structural unit in the ethylene/propylene/non-conjugated polyene copolymer (B-2) as the polymer (B) was determined by 13C-NMR measurement. The measured values were obtained using an ECX400P type nuclear magnetic resonance apparatus (manufactured by JEOL Ltd.) at a measurement temperature of 120°C, a measurement solvent of ortho-dichlorobenzene/deuterated benzene = 4/1, and an accumulation of 8000 times. The 13CC-NMR spectrum of the polymer was obtained by measurement.

[Limiting viscosity]
The intrinsic viscosity [η] was measured at a temperature of 135° C. and a measurement solvent of decalin.
[Weight average molecular weight (Mw) and molecular weight distribution (Mw/Mn)]
The ultimate weight average molecular weight (Mw) of the olefinic copolymer (A) and the molecular weight distribution (Mw/Mn) represented by the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) were determined by gel permeation chromatography. It was calculated by a standard polystyrene conversion method using graphics (GPC). Measurement conditions are as follows.
Measuring device: GPC (ALC/GPC 150-C plus type, integrated differential refractometer detector, manufactured by Waters)
Column: two GMH6-HT (manufactured by Tosoh Corporation) and two GMH-HTL (manufactured by Tosoh Corporation) connected in series Eluent: o-dichlorobenzene Column temperature: 140°C
Flow rate: 1.0 mL/min

[Dynamic viscoelasticity measurement]
The olefinic copolymer (A) and the polymer (B) were molded into a 2 mm thick press sheet, and a strip was cut out to measure the effective size of the test piece with a length of 20 mm, a width of 10 mm, and a thickness of 2 mm. . Using a viscoelasticity measuring device ARES (manufactured by TA Instruments Japan Inc.), the temperature dependence of the dynamic viscoelasticity of the olefinic copolymer was measured under the following measurement conditions. The ratio (G″/G′: loss tangent) between the storage elastic modulus (G′) and the loss elastic modulus (G″) obtained in the measurement was defined as tan δ. When tan δ is plotted against temperature, an upward convex curve or peak is obtained, the temperature at the top of the peak is taken as the glass transition temperature, ie tan δ, and the maximum value at that temperature is measured and taken as the peak.
(Measurement condition)
Frequency: 1.0Hz
Temperature: -70 to 100°C
Ramp Rate: 4.0°C/min Strain: 0.5%

[Mooney viscosity]
The Mooney viscosity of the polymer (B) was measured according to JIS K6300, and ML1+4 (125°C) at 125°C.

[Dissipation factor measurement]
Using a loss factor measuring device (manufactured by Ono Sokki Co., Ltd.), it was measured by the cantilever beam method at 23° C. in accordance with JIS K7391. A crosslinked body of a polymer composition cut from a press sheet into a width of 10 mm × length of 160 mm is attached to a base layer made of SUS430 with a width of 10 mm × length of 200 mm × thickness of 1.0 mm to form a test piece and measure. did. At this time, the effective length of the test piece is 160 mm, and the fixed portion is 200 mm. In the resonance frequency of the obtained frequency response function (mobility: V/F), using the point at which the resonance frequency is reduced by 3 dB, the loss factor was obtained by the half width method to obtain the loss factor at 1000 Hz. The higher the loss factor, the better the damping properties.

[density]
Using a press sheet with a thickness of 2 mm, the density was measured according to JIS K6268.

[Production of ethylene/α-olefin/non-conjugated polyene copolymer (B-2)]
[Production Example 1]
Ethylene/α-olefin/non-conjugated polyene copolymer (B-2) as polymer (B) according to the present invention, ethylene/propylene/5-ethylidene-2-norbornene copolymer (b-2) was prepared by the following polymerization method.

A terpolymerization reaction consisting of ethylene, propylene and 5-ethylidene-2-norbornene (ENB) was continuously carried out at 95° C. using a 300 L polymerization vessel equipped with a stirring blade. Hexane (final concentration: 90.8% by weight) was used as the polymerization solvent, and 3.3% by weight of ethylene, 2.5% by weight of propylene, and 0.3% by weight of ENB were fed continuously. While maintaining the polymerization pressure at 0.8 MPa, the metallocene catalyst [N-(1,1-dimethylethyl)-1,1-dimethyl-1-[(1,2,3,3A,8A- η)-1,5,6,7-tetrahydro-2-methyl-S-indacene-1-yl]silaneaminate (2-)-κN][(1,2,3,4-η)-1, 3-Pentadiene]-titanium was continuously supplied to 0.0025 mmol/L. Also, (C6H5)3CB(C6F5)4 as a co-catalyst and triisobutylaluminum (TIBA) as an organoaluminum compound were continuously supplied at 0.0145 mmol/L and 0.010 mmol/L, respectively. The above metallocene-based catalyst was obtained by synthesizing according to the method described in International Publication No. 98/49212 pamphlet.

Thus, a 10.8% by weight solution of an ethylene/propylene/ENB copolymer was obtained. A small amount of methanol was added to the polymerization reaction solution taken out from the bottom of the polymerization vessel to stop the polymerization reaction. A propylene/5-ethylidene-2-norbornene copolymer (b-2) was obtained. The structural unit content derived from ethylene in this polymer (b-2) was 57% by mass, and the total structural unit content derived from 5-ethylidene-2-norbornene (ENB) was 4.9% by mass. . The Mooney viscosity [ML1+4 (125°C)] of this polymer (b-2) was 79, and the peak indicating the maximum tan δ value of 1.8 was -32°C.

[Production of 4-methyl-1-pentene/α-olefin copolymer (A-1)]
[Production Example 2]
As the olefin polymer (A) according to the present invention, the 4-methyl-1-pentene/α-olefin copolymer (A-1) is a 4-methyl-1-pentene/propylene copolymer (a- 1) was prepared by the following polymerization method.

300 ml of normal hexane (dried over activated alumina in a dry nitrogen atmosphere) and 450 ml of 4-methyl-1-pentene were placed in a 1.5-liter SUS autoclave equipped with a stirring blade that had been sufficiently purged with nitrogen at 23°C. . The autoclave was charged with 0.75 ml of a 1.0 mmol/ml toluene solution of triisobutylaluminum (TIBAL), and a stirrer was turned.

Next, the autoclave was heated to an internal temperature of 60° C. and pressurized with propylene so that the total pressure was 0.40 MPa (gauge pressure). Subsequently, prepared in advance, 1 mmol of methylaluminoxane in terms of Al, diphenylmethylene (1-ethyl-3-t-butyl-cyclopentadienyl)(2,7-di-t-butyl-fluorenyl)zirconium 0.34 ml of a toluene solution containing 0.01 mmol of dichloride was pressurized into the autoclave with nitrogen to initiate polymerization. During the polymerization reaction, the temperature inside the autoclave was adjusted to 60°C. After 60 minutes from the start of the polymerization, 5 ml of methanol was injected into the autoclave with nitrogen to stop the polymerization, and the autoclave was depressurized to atmospheric pressure. Acetone was poured into the reaction solution while stirring.

The resulting solvent-containing polymer was dried at 100° C. under reduced pressure for 12 hours to obtain a 4-methyl-1-pentene/propylene copolymer (a-1). The structural unit content derived from 4-methyl-1-pentene in copolymer (a-1) was 72 mol %, and the structural unit content derived from propylene was 28 mol %. Further, the intrinsic viscosity [η] of the copolymer (a-1) is 1.5, the weight average molecular weight (Mw) is 337,000, the molecular weight distribution (Mw/Mn) is 2.1, and the maximum value of tan δ is One 2.8 peak was at 28°C.

[Example 1]
Using a Banbury mixer, at a filling rate of 70% and a rotor rotation speed of 50 rpm, 100 parts of the polymer (b-2) obtained in Polymerization Example 1 and the copolymer (a-1) obtained in Polymerization Example 2 ) 250 parts of carbon black (trade name: Asahi # 60G (manufactured by Asahi Carbon Co., Ltd.)) 195 parts, paraffin oil (trade name: Diana Process Oil PS-430 (manufactured by Idemitsu Kosan Co., Ltd.)) 165 parts, carbonic acid Calcium (trade name: Silver-W (manufactured by Shiraishi Calcium Co., Ltd.), stearic acid (trade name: powdered stearic acid Sakura (manufactured by NOF Corporation)) 2 parts, fatty acid ester (trade name: Structol WB212 (S&S Japan Co., Ltd.)) and 1 part of polyethylene glycol (trade name: PEG #4000 (Lion Co., Ltd.)) were kneaded, and the mixture was discharged. 10 parts of copolyparaphenylene/3,4′-oxydiphenylene/terephthalamide staple fiber (average fiber length 3 mm, fiber diameter 12 μm aramid staple fiber) (trade name: Technora staple fiber 3 mm (manufactured by Teijin Limited) , Sulfenamide vulcanization accelerator: N-cyclohexyl-2-benzothiazole sulfenamide (trade name: Suncellar CM (manufactured by Sanshin Chemical Industry Co., Ltd.)) 1.5 parts, dithiocarbamate vulcanization accelerator : Zinc dibutyldithiocarbamate (trade name: Suncellar BZ) 1.0 parts by mass, thiuram-based vulcanization accelerator: tetramethylthiuram disulfide (trade name: Suncella TT) 0.5 parts by mass, thiuram-based vulcanization accelerator: di Pentamethylenethiuram tetrasulfide (trade name: Suncellar TRA (manufactured by Sanshin Chemical Industry Co., Ltd.)) 0.5 parts, sulfur (trade name: Alphagran S-50EN (manufactured by Tochi Co., Ltd.)) 0.8 parts A polymer composition was obtained by adding and kneading.Using a hot press, the polymer composition was press-crosslinked (vulcanized) at 160 ° C. for 10 minutes to form a sheet of 2 mm in thickness. A crosslinked body (press sheet) made of the polymer composition was obtained as a vibration damping material.
Using the obtained crosslinked product of the polymer composition, evaluation was carried out according to each of the methods described above. Table 1 shows the results.

[Example 2]
Evaluation was carried out in the same manner as in Example 1, except that 250 parts of the copolymer (a-1) was changed to 350 parts. Table 1 shows the results.

[Example 3]
Short fibers of copolyparaphenylene/3,4'oxydiphenylene/terephthalamide (chopped fiber aramid short fibers with an average fiber length of 3 mm and a fiber diameter of 12 μm) (trade name: Technora Chopped Fiber 3 mm (manufactured by Teijin Limited) ) was added to 10 parts of polyparaphenylene terephthalamide short fibers (chopped fiber short fibers having an average fiber length of 3.5 mm and a fiber diameter of 12 μm) (trade name: Kevlar Cut Fiber 3.5 mm (DuPont-Toray Co., Ltd.) Evaluation was performed in the same manner as in Example 1, except that the amount was changed to 10 parts. Table 1 shows the results.

[Example 4]
Copolymer (a-1) 250 parts to 100 parts, carbon black (trade name: Asahi # 60G (manufactured by Asahi Carbon Co., Ltd.)) 195 parts to 100 parts, paraffin oil (trade name: Diana Process Oil PS -430 (manufactured by Idemitsu Kosan Co., Ltd.)) Evaluation was performed in the same manner as in Example 1, except that 165 parts was changed to 55 parts. Table 1 shows the results.

[Example 5]
Carbon black (trade name: Asahi # 60G (manufactured by Asahi Carbon Co., Ltd.)) 195 parts to 100 parts, paraffin oil (trade name: Diana Process Oil PS-430 (manufactured by Idemitsu Kosan Co., Ltd.)) 165 parts to 55 Copolyparaphenylene/3,4′oxydiphenylene/terephthalamide short fibers (average fiber length 3 mm, fiber diameter 12 μm, chopped fiber-like aramid short fibers) (trade name: Technora Chopped Fiber 3 mm (Teijin Limited) Co., Ltd.)) was added to 10 parts of polyparaphenylene terephthalamide short fibers (chopped fiber short fibers with an average fiber length of 3.5 mm and a fiber diameter of 12 μm) (trade name: Kevlar cut fiber 3.5 mm (Toray DuPont ( The evaluation was performed in the same manner as in Example 1, except that the amount was changed to 5 parts (manufactured by Co., Ltd.). Table 1 shows the results.

[Comparative Example 1]
Short fibers of copolyparaphenylene/3,4'oxydiphenylene/terephthalamide (chopped fiber aramid short fibers with an average fiber length of 3 mm and a fiber diameter of 12 μm) (trade name: Technora Chopped Fiber 3 mm (manufactured by Teijin Limited) ) was not used, and evaluation was performed in the same manner as in Example 1. Table 1 shows the results.

[Comparative Example 2]
Evaluation was performed in the same manner as in Example 1, except that the copolymer (a-1) was not blended. Table 1 shows the results.

[Comparative Example 3]
Copolymer (a-1) and copolyparaphenylene/3,4'oxydiphenylene/terephthalamide short fibers (chopped fiber aramid short fibers having an average fiber length of 3 mm and a fiber diameter of 12 μm) (trade name: Technora Chopped Fiber) Evaluation was performed in the same manner as in Example 1, except that 3 mm (manufactured by Teijin Limited) was not blended. Table 1 shows the results.

[Comparative Example 4]
Short fibers of copolyparaphenylene/3,4'oxydiphenylene/terephthalamide (chopped fiber aramid short fibers with an average fiber length of 3 mm and a fiber diameter of 12 μm) (trade name: Technora Chopped Fiber 3 mm (manufactured by Teijin Limited) ) was replaced with 10 parts of talc (trade name: Hytron A (manufactured by Takehara Chemical Industry Co., Ltd.)). Table 1 shows the results.

[Comparative Example 5]
Short fibers of copolyparaphenylene/3,4'oxydiphenylene/terephthalamide (chopped fiber aramid short fibers with an average fiber length of 3 mm and a fiber diameter of 12 μm) (trade name: Technora Chopped Fiber 3 mm (manufactured by Teijin Limited) Evaluation was performed in the same manner as in Example 1, except that 10 parts of talc (trade name: Hytron A (manufactured by Takehara Chemical Industry Co., Ltd.) was changed to 200 parts. The results are shown in Table 1.

As can be seen from Table 1, the vibration damping material composed of a crosslinked body using a polymer composition that satisfies the specific requirements according to the present invention has a very high loss factor, excellent vibration damping properties, and a low density, making it possible to reduce weight. It can be seen that it is possible and can be an excellent damping material (Examples 1 to 5).

On the other hand, when the organic short fibers (C) are not included (Comparative Example 2), the damping material comprising a crosslinked body using the polymer composition has a low loss factor and is inferior in damping properties (Comparative Example 1). In addition, a vibration damping material made of a crosslinked body using a polymer composition that does not contain the olefin copolymer (A) has a very low loss factor, is inferior in damping properties, has a high density, and is lightweight. inferior (Comparative Example 2).

In addition, a vibration damping material composed of a crosslinked body using a polymer composition containing neither the olefin copolymer (A) nor the organic staple fiber (C) has a very low loss factor and vibration damping properties. It has a high density and is inferior in lightness (Comparative Example 3).

Furthermore, even when 10 parts of talc as the plate-like filler of the prior art is used without using the organic short fibers (C), the loss factor is very low and the damping property is poor (Comparative Example 4). Similarly, when 200 parts of talc is used as a plate-like filler without using the organic short fibers (C), the loss factor is slightly improved, but the result is not high, and the density is high and the weight is light. It is inferior in the property (Comparative Example 5).

Claims (12)

Polymer (B) having a loss tangent tan δ peak found by dynamic viscoelasticity measurement in a temperature range of -60 ° C. or higher and less than 0 ° C., dynamic viscoelasticity measurement for 100 parts by mass of the polymer (B) 50 to 500 parts by mass of the olefin copolymer (A) having a loss tangent tan δ peak in the temperature range of 0 ° C. to 60 ° C. and an average fiber length of 0.1 mm to 12 mm A polymer composition characterized by containing 0.5 to 100 parts by mass of a certain organic short fiber (C). 2. The polymer composition according to claim 1, wherein said organic short fibers (C) are aramid short fibers. 3. The polymer composition according to claim 1, wherein the organic staple fibers (C) are polyparaphenylene terephthalamide staple fibers or copolyparaphenylene.3,4'-oxydiphenylene terephthalamide staple fibers. The olefin polymer (A) contains 16 to 95 mol% of the structural unit (i) derived from 4-methyl-1-pentene, and has an α-olefin (4-methyl- The content ratio of structural units (ii) derived from at least one α-olefin selected from (excluding 1-pentene) is 5 to 84 mol%, and the content ratio of structural units (iii) derived from non-conjugated polyenes is 0 4-methyl-1-pentene/α-olefin copolymer (A -1), the polymer composition according to any one of claims 1 to 3. 5. The polymer composition according to any one of claims 1 to 4, wherein the structural unit (ii) derived from the α-olefin of the olefin polymer (A) is a structural unit derived from propylene. The polymer (B) comprises at least one selected from ethylene rubber, diene rubber, chloroprene rubber, acrylic rubber, ethylene acrylic rubber, silicone rubber, epichlorohydrin rubber, urethane rubber, and chlorosulfonated polyethylene. 6. The polymer composition according to any one of 1 to 5. The polymer composition according to any one of claims 1 to 6, wherein the polymer (B) comprises an ethylene/α-olefin/non-conjugated polyene copolymer (B-2). 8. The polymer composition according to any one of claims 1 to 7, wherein the polymer composition contains a softening agent, and the content of the softening agent is 5 to 300 parts by mass with respect to 100 parts by mass of the polymer (B). polymer composition. 9. The polymer composition of claim 8, wherein said softening agent is paraffin oil. A damping material formed from the polymer composition according to any one of claims 1 to 9. A crosslinked product obtained by crosslinking the polymer composition according to any one of claims 1 to 9. A damping material comprising the crosslinked body according to claim 11 .