JP2008239686A - Vibration-damping composition and its molded product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vibration-damping composition which excels in vibration-damping properties and sound absorbing qualities, excels in moldability, heat resistance, flexibility, and rubber elasticity, has no tackiness, and furthermore excels in durability compared to the conventional olefin based vibration damper and its molded product. <P>SOLUTION: The vibration-damping composition comprises a specific syndiotactic α-olefin copolymer (A), an olefin thermoplastic elastomer (B) having a polyolefin resin (a) and an ethylene copolymer rubber (b) as essential components, and if necessary, at least one polyolefin resin (C) selected from syndiotactic polypropylene (c-1), isotactic polypropylene (c-2), and polybutene (c-3). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vibration damping composition obtained from an olefinic thermoplastic elastomer and a molded body thereof.

In recent years, the amount of olefinic thermoplastic elastomers used as a material with relatively little environmental impact is increasing in automobile parts, electrical product parts, building materials and the like.
Olefin-based thermoplastic elastomer materials are excellent in that they are lightweight, have excellent moldability and parts processability, are easily recyclable, and do not generate harmful gases during combustion.

  Moreover, in automobiles, electrical products, and houses, quietness is required, and many elastomer materials used in these fields are required to have vibration damping properties and sound absorption properties. However, the conventional olefin-based thermoplastic elastomer material has never been excellent in vibration damping properties and sound absorption properties, so that improvement has been desired.

  So far, as vibration-damping and sound-absorbing olefin-based soft materials, for example, synthetic rubbers such as diene rubbers, olefin-based polymers, inorganic fillers, rosin or petroleum resins modified with organic peroxides have been proposed. (Patent Document 1). However, since this composition uses rosin or petroleum resin as a tackifier, it has tackiness and its use is limited.

In addition, a low-density elastomeric polypropylene resin composition produced using a single site catalyst has been proposed as a damping material (Patent Document 2). However, since this vibration damping material is inferior in rubber elasticity, its use is still limited.
JP-A-6-033034 JP2001-253981

  It solves the problems associated with the prior art, and is superior in vibration damping and sound absorbing properties, superior in moldability, heat resistance and flexibility, rubber elasticity, and adhesiveness compared to conventional olefin-based vibration damping materials In addition, the present invention proposes a vibration-damping composition having excellent durability and a molded product thereof.

<Overview>
The vibration damping composition of the present invention comprises:
A control system comprising an olefinic thermoplastic elastomer (B) comprising a syndiotactic α-olefin copolymer (A), a polyolefin resin (a) and an ethylene copolymer rubber (b) as essential components. A vibratory composition comprising:
Here, the syndiotactic α-olefin copolymer (A) is ¹³ C-NMR measured with a 1,2,4-trichlorobenzene solution, and the absorption of the methyl group of the propylene unit is based on tetramethylsilane. The sum of the absorption intensities observed at about 20.0-21.0 ppm is 0.5 or more of the absorption intensity of about 19.0-22.0 ppm attributed to propylene methyl;
(A-1) a repeating unit derived from propylene;
(A-2) a repeating unit derived from ethylene;
(A-3) a repeating unit derived from at least one olefin selected from olefins having 4 to 20 carbon atoms, and, if necessary,
(A-4) consisting of a repeating unit derived from at least one polyene selected from conjugated polyenes and non-conjugated polyenes,
When the total amount of the unit (a-1), the unit (a-2) and the unit (a-3) is 100 mol%, the unit (a-1) is 30 to 78 mol%, and the unit (a- 2) 1-30 mol% of units and 1-50 mol% of the above-mentioned (a-3) units (provided that the total amount of (a-2) units and (a-3) units is 21 to 70) The unit (a-4) is 0 to 30 mol% with respect to 100 mol% of the total amount of the units (a-1), (a-2) and (a-3). It is contained in quantity and is substantially a syndiotactic structure.

  In addition to the syndiotactic α-olefin copolymer (A), the olefin thermoplastic elastomer (B) having the polyolefin resin (a) and the ethylene copolymer rubber (b) as essential components, At least one polyolefin resin (C) selected from tactic polypropylene (c-1), isotactic polypropylene (c-2), and polybutene (c-3) may be included.

  Further, the syndiotactic α-olefin copolymer (A) does not have a melting peak measured by a differential scanning calorimeter (DSC), and has an intrinsic viscosity [η] measured in decalin at 135 ° C. It is preferably in the range of 0.01 to 10 dl / g, the molecular weight distribution by GPC is 4 or less, and the glass transition temperature Tg is −5 ° C. or less.

  In addition, the molded article of the present invention can be obtained by molding the vibration-damping composition by a known molding method such as injection molding, extrusion molding, calendar molding, compression molding, or vacuum molding.

  The vibration damping composition as described above is not only excellent in vibration damping properties, but also excellent in sound absorption, less environmental impact, excellent moldability, heat resistance, flexibility and rubber elasticity, no stickiness, Furthermore, it is excellent in durability.

<Specific Description of the Invention>
Hereinafter, the vibration damping composition according to the present invention will be specifically described.
The vibration damping composition according to the present invention comprises:
It consists of a syndiotactic α-olefin copolymer (A) and an olefinic thermoplastic elastomer (B) whose essential components are a polyolefin resin (a) and an ethylene copolymer rubber (b).

  1 to 99 parts by weight of syndiotactic α-olefin copolymer (A) with respect to 100 parts by weight in total of the syndiotactic α-olefin copolymer (A) and the olefin thermoplastic elastomer (B), Preferably 5 to 95 parts by weight, more preferably 10 to 90 parts by weight, particularly preferably 15 to 85 parts by weight, most preferably 20 to 80 parts by weight, olefinic thermoplastic elastomer (B) 99 to 1 part by weight, preferably Is blended at a ratio of 95 to 5 parts by weight, more preferably 90 to 10 parts by weight, particularly preferably 85 to 15 parts by weight, and most preferably 80 to 20 parts by weight.

  In addition to the syndiotactic α-olefin copolymer (A) and the olefin thermoplastic elastomer (B), syndiotactic polypropylene (c-1), isotactic polypropylene (c-2), polybutene ( At least one polyolefin resin (C) selected from c-3) can also be blended.

  In that case, the syndiotactic α-olefin copolymer (A), the olefinic thermoplastic elastomer (B) and the polyolefin resin (C) in total 100 parts by weight are combined with the syndiotactic α-olefin copolymer. 1 to 98 parts by weight of polymer (A), preferably 5 to 95 parts by weight, more preferably 10 to 90 parts by weight, particularly preferably 17 to 85 parts by weight, most preferably 20 to 80 parts by weight, olefinic thermoplastic Elastomer (B) 98-1 part by weight, preferably 94-4 parts by weight, more preferably 87-7 parts by weight, particularly preferably 80-12 parts by weight, most preferably 75-15 parts by weight, and polyolefin resin ( C) 1 to 70 parts by weight, preferably 1 to 50 parts by weight, more preferably 3 to 30 parts by weight, particularly preferably 3 to 25 parts by weight, most preferably Or it mix | blends in the ratio of 5-20 weight part.

  Further, the syndiotactic α-olefin copolymer (A) does not have a melting peak measured by a differential scanning calorimeter (DSC), and has an intrinsic viscosity [η] measured in decalin at 135 ° C. It is preferably in the range of 0.01 to 10 dl / g, the molecular weight distribution by GPC is 4 or less, and the glass transition temperature Tg is −5 ° C. or less.

  In addition, the molded article of the present invention can be obtained by molding the vibration-damping composition by a known molding method such as injection molding, extrusion molding, calendar molding, compression molding, or vacuum molding.

Syndiotactic α-olefin copolymer (A)
First, the syndiotactic α-olefin copolymer (A) will be described.

The syndiotactic α-olefin copolymer (A) according to the present invention is ¹³ C-NMR measured with a 1,2,4-trichlorobenzene solution, and the absorption of methyl groups of propylene units is based on tetramethylsilane. The total absorption intensity observed at about 20.0 to 21.0 ppm is attributed to propylene methyl, and the total absorption intensity of about 19.0 to 22.0 ppm is approximately 19.0 to 22. The absorption strength of 0 ppm is 0.5 or more, preferably 0.6 or more, and more preferably 0.7 or more.

This syndiotactic structure is measured as follows. That is, 0.35 g of a sample is dissolved by heating in 2.0 ml of hexachlorobutadiene. After this solution is filtered through a glass filter (G2), 0.5 ml of deuterated benzene is added and charged into an NMR tube having an inner diameter of 10 mm. And ¹³ C-NMR measurement is performed at 120 degreeC using the JEOL GX-500 type | mold NMR measuring apparatus. The number of integration is 10,000 times or more. When the syndiotactic α-olefin copolymer (A) is in such a range, the syndiotactic property is excellent and the transparency, flexibility, and wear resistance tend to be excellent.

  The syndiotactic α-olefin copolymer (A) according to the present invention is derived from an ethylene component unit of 1 to 30 mol%, a propylene component unit of 30 to 78 mol%, and an α-olefin having 4 to 20 carbon atoms. The component unit is 1 to 50 mol% (here, the total component unit amount in the copolymer (A) is 100 mol%, and the ethylene component unit and the component unit derived from an α-olefin having 4 to 20 carbon atoms) The total amount is 22 to 70 mol%), preferably 3 to 25 mol% of ethylene component units, 35 to 75 mol% of propylene component units, and 10 to 10 α-olefin derived component units having 4 to 20 carbon atoms. 45 mol% (here, the total amount of the component units in the copolymer (A) is 100 mol%, and the total amount of ethylene component units and component units derived from α-olefin having 4 to 20 carbon atoms is 25 to 65) Mol%), particularly preferred 3 to 25 mol% of ethylene component units, 35 to 65 mol% of propylene component units, and 20 to 45 mol% of component units derived from α-olefins having 4 to 20 carbon atoms (herein in the copolymer (A)) The total amount of the ethylene component unit and the component unit derived from the α-olefin having 4 to 20 carbon atoms is 35 to 65 mol%), more preferably 5 ethylene component units. -25 mol%, propylene component units are contained in 40-65 mol%, and C4-20 α-olefin-derived component units are contained in the copolymer (I). The total amount of the ethylene unit and the component unit derived from the α-olefin having 4 to 20 carbon atoms is 35 to 60 mol%). Further, it is derived from at least one polyene selected from conjugated polyenes and non-conjugated polyenes with respect to 100 mol% of the total amount of ethylene component units, propylene component units, and component units derived from α-olefins having 4 to 20 carbon atoms. The repeating unit may be contained in an amount of 0 to 30 mol%, preferably 0 to 25 mol%. In such an amount, an ethylene component, a propylene component, a component derived from an α-olefin having 4 to 20 carbon atoms, and a component derived from at least one polyene selected from a conjugated polyene and a nonconjugated polyene used as necessary are contained. The syndiotactic α-olefin copolymer (A) has good compatibility with the thermoplastic resin, and the resulting vibration damping composition has flexibility, rubber elasticity, scratch resistance, and wear resistance. There is a tendency to demonstrate.

  The component (a-3) used when preparing such a syndiotactic α-olefin copolymer (A) has a carbon number of 4 to 20, preferably 4 to 12 in particular. It is not limited and may be linear or may have a branch.

  Specific examples of such component (a-3) include 1-butene, 2-butene, 1-pentene, 1-hexene, 1-heptane, 1-octene, 1-nonene, and 1-decene. 1-undecene, 1-dodecene, 3-methyl-1-butene, 3-methyl-1-pentene, 4-methyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene 4,4-dimethyl-1-pentene, 4-ethyl-1-hexene, 3-ethyl-1-hexene and the like. 1-butene, 1-hexene, 1-octene, 1-decene, 4-methyl -1-pentene is preferable, 1-butene, 1-hexene, 1-octene, and 1-decene are preferable, and 1-butene is particularly preferable. These components (a-3) can be used alone or in combination of two or more. For example, one α-olefin (a) selected from α-olefins having 4 to 20 carbon atoms and α different from the above (a) selected from the α-olefins having 4 to 20 carbon atoms. -Olefin (B) is used in an amount ratio of (A) / (B) = (50 to 99 mol%) / (1 to 50 mol%) ((A) + (B) = 100 mol%) Can do.

  The repeating unit derived from at least one polyene selected from (a-4) conjugated polyene and non-conjugated polyene used when preparing the syndiotactic α-olefin copolymer (A) is as follows: It is a repeating unit derived from at least one polyene selected from conjugated polyenes and non-conjugated polyenes.

  Specific examples of the conjugated polyene include 1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene, 1,3-heptadiene, 1,3-octadiene, 1-phenyl-1,3-butadiene, 1- Phenyl-2,4-pentadiene, isoprene, 2-ethyl-1,3-butadiene, 2-propyl-1,3-butadiene, 2-butyl-1,3-butadiene, 2-pentyl-1,3-butadiene, Conjugated dienes such as 2-hexyl-1,3-butadiene, 2-heptyl-1,3-butadiene, 2-octyl-1,3-butadiene, 2-phenyl-1,3-butadiene; 1,3,5- Examples thereof include conjugated trienes such as hexatriene. Of these, butadiene, isoprene, pentadiene, hexadiene, and octadiene are preferable, and butadiene and isoprene are particularly preferable in terms of excellent copolymerizability.

Specific examples of non-conjugated polyenes include dicyclopentadiene, 1,4-hexadiene, cyclooctadiene, methylene norbornene, ethylidene norbornene, vinyl norbornene, 4-methyl-1,4-hexadiene, 5-methyl-1,4- Hexadiene, 4-ethyl-1,4-hexadiene, 5-methyl-1,4-heptadiene, 5-ethyl-1,4-heptadiene, 5-methyl-1,5-heptadiene, 6-methyl-1,5- Heptadiene, 5-ethyl-1,5-heptadiene, 4-methyl-1,4-octadiene, 5-methyl-1,4-octadiene, 4-ethyl-1,4-octadiene, 5-ethyl-1,4- Octadiene, 5-methyl-1,5-octadiene, 6-methyl-1,5-octadiene, 5-ethyl-1,5-octadiene, 6-ethyl-1,5-octadiene, 6-methyl-1,6- Octadiene, 7-methyl-1,6-octadiene, 6-ethyl-1,6-octadiene, 4-methyl-1,4-nonadiene, 5-methyl-1,4-nonadiene 4-ethyl-1,4-nonadiene, 5-ethyl-1,4-nonadiene, 5-methyl-1,5-nonadiene, 6-methyl-1,5-nonadiene, 5-ethyl-1,5- Nonadiene, 6-ethyl-1,5-nonadiene, 6-methyl-1,6-nonadiene, 7-methyl-1,6-nonadiene, 6-ethyl-1,6-nonadiene, 7-ethyl-1,6- Nonadiene, 7-methyl-1,7-nonadiene, 8-methyl-1,7-nonadiene, 7-ethyl-1,7-nonadiene, 5-methyl-1,4-decadiene, 5-ethyl-1,4- Decadiene, 5-methyl-1,5-decadiene, 6-methyl-1,5-decadiene, 5-ethyl-1,5-decadiene, 6-ethyl-1,5-decadiene, 6-methyl-1,6- Decadiene, 7-methyl-1,6-decadiene, 6-ethyl-1,6-decadiene, 7-ethyl-1,6-decadiene, 7-methyl-1,7-decadiene, 8-methyl-1,7- Decadiene, 7-ethyl-1,7-decadiene, 8-ethyl-1,7-decadiene, 8-methyl-1,8-decadiene, 9-methyl-1,8-decadiene, 8-ethi Non-conjugated dienes such as lu-1,8-decadiene, 9-methyl-1,8-undecadiene;
6,10-dimethyl-1,5,9-undecatriene, 4,8-dimethyl-1,4,8-decatriene, 5,9-dimethyl-1,4,8-decatriene, 6,9-dimethyl- 1,5,8-decatriene, 6,8,9-trimethyl-1,5,8-decatriene, 6-ethyl-10-methyl-1,5,9-undecatriene, 4-ethylidene-1,6- Octadiene, 7-methyl-4-ethylidene-1,6-octadiene, 4-ethylidene-8-methyl-1,7-nonadiene, 7-methyl-4-ethylidene-1,6-nonadiene, 7-ethyl-4- Ethylidene-1,6-nonadiene, 6,7-dimethyl-4-ethylidene-1,6-octadiene, 6,7-dimethyl-4-ethylidene-1,6-nonadiene, 4-ethylidene-1,6-decadiene, 7-methyl-4-ethylidene-1,6-decadiene, 7-methyl-6-propyl-4-ethylidene-1,6-octadiene, 4-ethylidene-1,7-nonadiene, 8-methyl-4-ethylidene- Non-conjugated trienes such as 1,7-nonadiene and 4-ethylidene-1,7-undecadiene It is below.
Such non-conjugated polyene is preferable in that it has excellent wear resistance when crosslinked.

  Among these, 5-ethylidene-2-norbornene, 5-vinyl-2-norbornene, dicyclopentadiene (DCPD), 4,8-dimethyl-1,4,8-decatriene (DMDT), 4-ethylidene-8- Methyl-1,7-nonadiene (EMND) is preferred. (A-4) Two or more types of units may be contained.

  In the syndiotactic α-olefin copolymer (A), a component unit derived from an aromatic vinyl compound such as styrene, or a component unit derived from the polyene unsaturated compound (polyene) having two or more double bonds. , Component units composed of alcohol, carboxylic acid, amine, and derivatives thereof may be included.

  The syndiotactic α-olefin copolymer (A) has an intrinsic viscosity [η] measured in decalin at 135 ° C. of usually 0.01 to 10 dl / g, preferably 0.05 to 10 dl / g. It is desirable to be. When the intrinsic viscosity [η] of the syndiotactic α-olefin copolymer (A) is within the above range, the properties such as weather resistance, ozone resistance, heat aging resistance, low temperature characteristics, dynamic fatigue resistance, etc. It is a syndiotactic α-olefin copolymer excellent in.

  This syndiotactic α-olefin copolymer (A) has a single glass transition temperature, and the glass transition temperature Tg measured by a differential scanning calorimeter (DSC) is usually −5 ° C. or lower, preferably Is preferably in the range of −10 ° C. or lower, particularly preferably −15 ° C. or lower. When the glass transition temperature Tg of the syndiotactic α-olefin copolymer (A) is within the above range, the cold resistance and low temperature characteristics are excellent.

The molecular weight distribution measured by GPC (Mw / Mn, polystyrene conversion, Mw: weight average molecular weight, Mn: number average molecular weight) is 5 or less, preferably 1.5 to 4.0, more preferably 1.5 to 3. 0 is preferred. When it is within this range, the vibration-damping composition has good scratch resistance, wear resistance, and impact resistance, which is preferable.
Moreover, it is desirable that there is no melting peak measured by a differential scanning calorimeter (DSC). In this case, the vibration damping composition is excellent in flexibility, scratch resistance, wear resistance, and impact resistance.

[Production of Syndiotactic α-Olefin Copolymer (A)]
Such a syndiotactic α-olefin copolymer (A) can be obtained by copolymerizing propylene, ethylene and α-olefin in the presence of the metallocene catalyst shown below.

As such a metallocene catalyst,
(X) a transition metal compound represented by the following general formula (1);
(Y) (y-1) a compound that reacts with the transition metal M in the transition metal compound (a) to form an ionic complex,
(Y-2) an organoaluminum oxy compound,
(Y-3) at least one catalyst system comprising at least one compound selected from organoaluminum compounds.

[In the formula (1), M is Ti, Zr, Hf, Rn, Nd, Sm or Ru, and Cp ¹ and Cp ² are cyclopentadienyl group, indenyl group, fluorenyl group π-bonded to M, Or a derivative group thereof, X ¹ and X ² are anionic ligands or neutral Lewis base ligands, and Z is a C, O, B, S, Ge, Si or Sn atom, or these A group containing an atom. ]

Among the transition metal compounds represented by the general formula (1), a transition metal compound in which Cp ¹ and Cp ² are different groups can be mentioned, and more preferably any one group of Cp ¹ and Cp ² Transition metal compounds in which is a cyclopentadienyl group or a derivative group thereof and the other group is a fluorenyl group or a derivative group thereof. Among these, it is preferable that either one of Cp ¹ and Cp ^{2 is} a cyclopentadienyl group or a derivative group thereof, and the other group is a fluorenyl group or a derivative group thereof.

  In the present invention, the above-mentioned metallocene catalyst is preferably used as the syndiotactic α-olefin copolymer (A) production catalyst. A known titanium catalyst comprising a solid titanium catalyst component and an organoaluminum compound, or a vanadium catalyst comprising a soluble vanadium compound and an organoaluminum compound can also be used.

  In the present invention, in the presence of the metallocene-based catalyst as described above, at least one polyene selected from ethylene, propylene and α-olefin, and optionally conjugated polyene and non-conjugated polyene is copolymerized in a normal liquid phase. Let At this time, a hydrocarbon solvent is generally used, but propylene may be used as a solvent. Copolymerization can be carried out by either a batch method or a continuous method.

  When a metallocene catalyst is used and copolymerization is carried out by a batch method, the transition metal compound (x) in the polymerization system is usually 0.00005 to 1 mmol, preferably 0.0001 to 1 liter per polymerization volume. The amount used is 0.5 mmol.

  The ionized ionic compound (y-1) is a molar ratio of the ionized ionic compound to the transition metal compound (x) ((y-1) / (x)), and is 0.5 to 20, preferably 1 to 10. Is used in such an amount.

  The organoaluminum oxy compound (y-2) has a molar ratio (Al / M) of aluminum atoms (Al) to transition metal atoms (M) in the transition metal compound (x) of 1 to 10000, preferably 10 to 5000. Is used in such an amount that The organoaluminum compound (y-3) is usually used in an amount of about 0 to 5 mmol, preferably about 0 to 2 mmol, per liter of polymerization volume.

The copolymerization reaction is usually performed at a temperature in the range of −20 to 150 ° C., preferably 0 to 120 ° C., more preferably 0 to 100 ° C., and a pressure exceeding 0 to 80 kg / cm ² , preferably exceeding 0. Under conditions ranging up to 50 kg / cm ² .

  The reaction time (average residence time when polymerization is carried out in a continuous process) varies depending on conditions such as catalyst concentration and polymerization temperature, but is usually 5 minutes to 3 hours, preferably 10 minutes to 1.5 hours. It is.

  Ethylene, propylene and α-olefin are respectively supplied to the polymerization system in such an amount that a syndiotactic α-olefin copolymer (A) having a specific composition as described above can be obtained. In the copolymerization, a molecular weight regulator such as hydrogen can be used. When ethylene, propylene, and α-olefin are copolymerized as described above, the syndiotactic α-olefin copolymer (A) is usually obtained as a polymerization liquid containing the same. This polymerization solution is treated by a conventional method to obtain a syndiotactic α-olefin copolymer (A).

Olefin-based thermoplastic elastomer (B)
The olefinic thermoplastic elastomer (B) used in the present invention comprises an olefinic resin (a) and an ethylene copolymer rubber (b) as essential components.

<Olefin resin (a)>
The olefin resin (a) used in the present invention comprises a high molecular weight solid product obtained by polymerizing one or more monoolefins by either the high pressure method or the low pressure method. Examples of such a resin include isotactic and syndiotactic monoolefin polymer resins. These representative resins are commercially available.

  Specific examples of suitable raw material olefins for the olefin resin (a) include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene and 2-methyl-1- Examples include propene, 3-methyl-1-pentene, 4-methyl-1-pentene, and 5-methyl-1-hexene. These olefins may be used alone or in combination of two or more.

  The polymerization mode may be random type or block type, and any polymerization mode can be adopted as long as a resinous material is obtained. These olefinic resins may be used alone or in combination of two or more.

  Among these olefin resins (a), propylene polymers, specifically, propylene homopolymers, propylene / ethylene block copolymers, propylene / ethylene or propylene / ethylene / butene random copolymers are particularly preferable.

  The polymerization form may be either isotactic or syndiotactic, but isotactic is particularly excellent in heat resistance.

  The olefin resin (a) used in the present invention has an MFR (ASTM D 1238-65T, 230 ° C.) of usually 0.01 to 100 g / 10 minutes, particularly 0.05 to 50 g / 10 minutes. preferable.

  The olefin resin (a) has a role of improving the fluidity and heat resistance of the composition.

  In the present invention, the olefin resin (a) is preferably 10 parts by weight or more and less than 80 parts by weight with respect to 100 parts by weight of the total amount of the olefin resin (a) and the ethylene copolymer rubber (b). More preferably, it is used at a ratio of 15 to 60 parts by weight.

  When the olefin-based resin (a) is used in the above proportion, an olefin-based thermoplastic elastomer composition (B) excellent in heat resistance, flexibility and rubber elasticity and excellent in moldability is obtained.

<Ethylene copolymer rubber (b)>
The ethylene copolymer rubber (b) used in the present invention is an amorphous random elastic copolymer rubber made of ethylene and an α-olefin having 3 to 20 carbon atoms, or ethylene and 3 to 3 carbon atoms. It is an amorphous random elastic copolymer rubber composed of 20 α-olefins and non-conjugated polyene.

  The ethylene-copolymer rubber (b) has a molar ratio of ethylene to α-olefin of usually 55/45 to 85/15, and among these, those in the range of 60/40 to 83/17 are preferred.

  Specific examples of the non-conjugated polyene include dicyclopentadiene, 1,4-hexadiene, cyclooctadiene, methylene norbornene, ethylidene norbornene, and vinyl norbornene. Of these, ethylene / propylene / non-conjugated diene copolymer rubber and ethylene / 1-butene / non-conjugated diene copolymer rubber are preferred, and ethylene / propylene / non-conjugated diene copolymer rubber, particularly ethylene / propylene. -Ethylidene norbornene copolymer rubber and ethylene / propylene / vinyl norbornene copolymer rubber are particularly preferable in that a thermoplastic elastomer having an appropriate cross-linked structure can be obtained.

  The Mooney viscosity [ML1 + 4 (100 ° C.)] of the ethylene copolymer rubber (b) used in the present invention is preferably in the range of 50 to 300, preferably 100 to 200.

  Moreover, it is preferable that the iodine value of this ethylene-type copolymer rubber (b) is 3-30, and it is especially preferable that it exists in the range of 5-25. When the iodine value of the ethylene-based copolymer rubber (b) is in such a range, a thermoplastic elastomer composition (B) excellent in moldability and rubber elasticity is obtained by being well-crosslinked.

  The ethylene copolymer rubber (b) used in the present invention may be a so-called oil-extended product containing a softening agent. By using the oil-extended product, an elastomer composition having more flexibility can be obtained. As the softening agent that can be used for the oil-extended product, a softening agent that is usually used for rubber can be used.

Specifically, petroleum-based substances such as process oil, lubricating oil, paraffin, liquid paraffin, petroleum asphalt, and petroleum jelly;
Coal tars such as coal tar and coal tar pitch;
Fatty oils such as castor oil, linseed oil, rapeseed oil, soybean oil, coconut oil;
Waxes such as tall oil, beeswax, carnauba wax, lanolin;
Fatty acids such as ricinoleic acid, palmitic acid, stearic acid, barium stearate, calcium stearate or metal salts thereof;
Synthetic polymer materials such as petroleum resin, coumarone indene resin, atactic polypropylene;
Ester plasticizers such as dioctyl phthalate, dioctyl adipate, dioctyl sebacate;
Other examples include microcrystalline wax, sub (factis), liquid polybutadiene, modified liquid polybutadiene, and liquid thiocol.

  Among these softeners, paraffinic process oils are particularly preferable, and high viscosity type paraffinic process oils having a low content of low molecular weight components that are volatile are particularly preferable. Here, the high viscosity type refers to one having a kinematic viscosity at 40 ° C. in the range of 100 to 1000 centistokes.

  In the present invention, the softener is used in a proportion of 150 parts by weight or less, preferably 2 to 100 parts by weight, more preferably 5 to 60 parts by weight, based on 100 parts by weight of the ethylene copolymer rubber (b). .

  The ethylene copolymer rubber (b), which may be oil-extended as necessary, has a total amount of 100 parts by weight of the olefin resin (a) and the ethylene copolymer rubber (b). It is used in a proportion of 20 to 90 parts by weight, preferably 40 to 85 parts by weight.

  In the present invention, in addition to the ethylene copolymer rubber (b), a rubber other than the ethylene copolymer rubber (b) and the ethylene copolymer rubber (b) within a range not impairing the object of the present invention. Can also be used in combination. Examples of the rubber other than the ethylene copolymer rubber (b) include styrene / butadiene rubber and hydrogenated products thereof, styrene / isoprene rubber and hydrogenated products thereof, polybutadiene rubber, polyisoprene rubber, nitrile rubber, and butyl rubber. , Polybutylene rubber, natural rubber, silicon rubber and the like.

<Other ingredients>
In addition to the olefin resin (a) and the ethylene copolymer rubber (b), a softener and / or an inorganic filler can be blended with the olefin thermoplastic elastomer (B) according to the present invention.

  As described above, the softening agent may be oil-extended into the ethylene copolymer rubber (b), or may be added later without oil-extended. In the case where the ethylene copolymer rubber (b) is added later without being oil-extended, the same softening agent as described above can be used.

  In the case where it is added later without oil-extended, the amount of the softening agent is 100 parts by weight with respect to the total amount of the olefin-based resin (a) and the ethylene-based copolymer rubber (b) together with the oil-extended component. 100 parts by weight or less, preferably 3 to 80 parts by weight, more preferably 5 to 50 parts by weight. When the softening agent is used in the above ratio, the resulting thermoplastic elastomer composition is excellent in fluidity during molding and does not deteriorate the mechanical properties of the molded product. In this invention, when the usage-amount of a softener exceeds 100 weight part, it exists in the tendency for the heat resistance of the vibration damping composition obtained to fall.

  Specific examples of the inorganic filler used in the present invention include calcium carbonate, calcium silicate, clay, kaolin, talc, silica, diatomaceous earth, mica powder, asbestos, alumina, barium sulfate, aluminum sulfate, sulfuric acid. Examples include calcium, basic magnesium carbonate, molybdenum disulfide, graphite, glass fiber, glass sphere, shirasu balloon, basic magnesium sulfate whisker, titanium oxide, calcium titanate whisker, and aluminum borate whisker.

  In the present invention, the inorganic filler is a ratio of 100 parts by weight or less, preferably 2 to 70 parts by weight with respect to 100 parts by weight of the total amount of the olefin resin (a) and the ethylene copolymer rubber (b). Used in In this invention, when the usage-amount of an inorganic filler exceeds 100 weight part, it exists in the tendency for the rubber elasticity of a damping composition obtained and a moldability to fall.

  Furthermore, in the present invention, conventionally known heat stabilizers, anti-aging agents, weathering stabilizers, antistatic agents, crystal nucleating agents, metal soaps, waxes and the like are added to the olefinic thermoplastic elastomer (B). Further, it can be added within a range not impairing the object of the present invention.

The olefinic thermoplastic elastomer composition (B) according to the present invention comprises the above-mentioned olefinic resin (a) and ethylene copolymer rubber (b), and a softener and / or inorganic filler blended as necessary. After mixing with an agent, etc., it is obtained by dynamically heat-treating. Here, “dynamically heat-treating” means kneading in a molten state.
Moreover, the crosslinked olefinic thermoplastic elastomer composition (B) can be obtained by performing dynamic heat treatment in the presence of a crosslinking agent.

  The crosslinking agent used in this case is an organic peroxide, phenol resin, sulfur, hydrosilicone compound, amino resin, quinone or its derivative, amine compound, azo compound, epoxy compound, isocyanate, etc., thermosetting type The crosslinking agent generally used with rubber | gum is mentioned. Of these crosslinking agents, organic peroxides are particularly preferred.

  Specific examples of the organic peroxide used in the present invention include dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di- (tert-butylperoxy) hexane, 2, 5-dimethyl-2,5-di- (tert-butylperoxy) hexyne-3, 1,3-bis (tert-butylperoxyisopropyl) benzene, 1,1-bis (tert-butylperoxy) -3,3, 5-trimethylcyclohexane, n-butyl-4,4-bis (tert-butylperoxy) valerate, benzoyl peroxide, p-chlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, tert-butylperoxybenzoate, tert-butylperbenzoate Tert-butylperoxyisopropyl carbonate, diacetyl peroxide, lauroyl peroxide, tert-butylcumyl peroxide, and the like.

  Among these, 2,5-dimethyl-2,5-di- (tert-butylperoxy) hexane, 2,5-dimethyl-2,5-di- in terms of reactivity, odor, and scorch stability Bifunctional organic peroxides such as (tert-butylperoxy) hexyne-3,1,3-bis (tert-butylperoxyisopropyl) benzene are particularly preferred. Of these, 2,5-dimethyl-2,5-di- (tert-butylperoxy) hexane is most preferred.

  Such an organic peroxide is used in an amount of 0.02 to 3 parts by weight, preferably 0.05 to 1 part by weight with respect to 100 parts by weight of the whole object to be processed. When the blending amount of the organic peroxide is less than the above range, the resulting thermoplastic elastomer composition has a low degree of cross-linking, and therefore tends to be inferior in heat resistance, tensile properties and rubber elasticity of the vibration damping composition. On the other hand, if the blending amount is larger than the above range, the resulting thermoplastic elastomer composition may have an excessively high degree of crosslinking, resulting in a decrease in moldability of the vibration damping composition.

  In the present invention, in the crosslinking treatment with the organic peroxide, sulfur, p-quinonedioxime, p, p'-dibenzoylquinonedioxime, N-methyl-N-4-dinitrosoaniline, nitrosobenzene, diphenyl Peroxy crosslinking aids such as guanidine, trimethylolpropane-N, N'-m-phenylenedimaleimide, or divinylbenzene, triallyl cyanurate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, trimethylol Polyfunctional methacrylate monomers such as propane trimethacrylate and allyl methacrylate, and polyfunctional vinyl monomers such as vinyl butyrate and vinyl stearate can be blended.

  By using such a compound, a uniform and mild crosslinking reaction can be expected. In particular, divinylbenzene is most preferred in the present invention. Divinylbenzene is easy to handle, has good compatibility with the crystalline polyolefin resin (a) and the ethylene copolymer rubber (b), which are the main components of the cross-linked product, and an organic peroxide. Therefore, a thermoplastic elastomer composition having a uniform crosslinking effect by heat treatment and a balance between fluidity and physical properties can be obtained.

  The amount of the compound such as the above-mentioned crosslinking aid or polyfunctional vinyl monomer is usually 5 parts by weight or less, preferably 0.2 to 3 parts by weight with respect to 100 parts by weight of the whole object to be treated. Used in

  In order to accelerate the decomposition of organic peroxides, tertiary amines such as triethylamine, tributylamine, 2,4,6-tri (dimethylamino) phenol, aluminum, cobalt, vanadium, copper, calcium, zirconium, Decomposition accelerators such as naphthenates such as manganese, magnesium, lead, and mercury may be used.

  The dynamic heat treatment in the present invention is preferably performed in a non-open type apparatus, and is preferably performed in an inert gas atmosphere such as nitrogen or carbon dioxide. The temperature of the heat treatment ranges from the melting point of the crystalline polyolefin resin (a) to 300 ° C, and is usually 140 to 290 ° C, preferably 170 ° C to 270 ° C. The kneading time is usually 1 to 20 minutes, preferably 1 to 10 minutes. The applied shearing force is in the range of 10 to 10,000 sec-1, preferably 100 to 50,000 sec-1, in terms of shear rate.

  As the kneading apparatus, a mixing roll, an intensive mixer (for example, a Banbury mixer, a kneader), a single-screw or twin-screw extruder, and the like can be used.

  The olefinic thermoplastic elastomer (B) of the present invention is desirably statically heat-treated in hot air after the dynamic heat treatment as described above. The heat treatment is preferably performed at 80 to 130 ° C. for about 0.5 to 10 hours. By this heat treatment, residues of the crosslinking agent and the like can be removed, the odor of the obtained product can be reduced, or a product with good fogging properties can be obtained.

Olefin resin (C)
The olefin resin (C) used as necessary in the present invention is selected from at least one of syndiotactic polypropylene (c-1), isotactic polypropylene (c-2), and polybutene (c-3). It is. Only one type of resin may be used, or two to three types of resins may be added.

  The syndiotactic polypropylene (c-1) and isotactic polypropylene (c-2) used in the present invention are obtained by polymerizing propylene alone or propylene and one or more other monoolefins. Specific monoolefins include ethylene, propylene, 1-pentene, 1-hexene, 1-octene, 1-decene, 2-methyl-1-propene, 3-methyl-1-pentene, 4-methyl-1- Examples include pentene and 5-methyl-1-hexene. These polypropylenes are crystalline polypropylenes and contain propylene component units in a proportion exceeding 78 mol%. These representative resins are commercially available.

  The polybutene (c-3) used in the present invention is a 1-butene homopolymer or a copolymer of 1-butene and an olefin excluding 1-butene. Specific examples of the olefin include those described above. These olefins may be used alone or in combination of two or more. Examples of such polyolefins include 1-butene / ethylene random copolymer, 1-butene / propylene random copolymer, 1-butene / methylpentene copolymer, 1-butene / methylbutene copolymer, 1-butene. -Propylene / ethylene copolymer and the like. In such a copolymer, from the viewpoint of durability, the 1-butene content is preferably 50 mol% or more, more preferably 70 mol% or more, and particularly preferably 85% or more. . By using polybutene (c-3), the durability is excellent, and in particular, a change in gloss over time is suppressed.

  The olefin resin (C) used in the present invention has an MFR (ASTM D 1238-65T, 230 ° C.) of usually 0.01 to 100 g / 10 minutes, particularly 0.05 to 50 g / 10 minutes. preferable.

<Other ingredients>
In addition to the syndiotactic α-olefin copolymer (A), the olefin thermoplastic elastomer (B), and the polyolefin resin (C), the vibration damping composition according to the present invention includes a softener and / or an inorganic filler. Agents can be blended.
As the softener, the same softener as described above can be used.

  Moreover, as an inorganic filler used by this invention, the thing similar to what was described previously can be used.

  In the present invention, the softener and / or the inorganic filler is used in a total amount of 100 parts by weight of the syndiotactic α-olefin copolymer (A), the olefin thermoplastic elastomer (B), and the polyolefin resin (C). On the other hand, it is used in a proportion of 100 parts by weight or less, preferably 2 to 50 parts by weight. In the present invention, when the addition amount of the softening material exceeds 50 parts by weight together with that in the thermoplastic elastomer (B), the heat resistance of the resulting vibration damping composition and the molded product tends to decrease, When the amount of the inorganic filler used exceeds 100 parts by weight, the rubber elasticity and molding processability of the vibration-damping composition and the molded product obtained tend to be lowered.

  Furthermore, the vibration-damping composition according to the present invention contains conventionally known additives such as a heat stabilizer, an anti-aging agent, a weather stabilizer, an antistatic agent, a crystal nucleating agent, a lubricant, and the like. It is possible to add in the range which is not. In particular, the lubricant has an effect of further improving the scratch resistance and wear resistance of the resulting molded article, and is preferably added. Examples of the lubricant include higher fatty acid amides, metal soaps, waxes, silicone oils, fluorine polymers, and the like. In the present invention, among the vibration damping compositions, among them, silicone oil and / or fluorine-based polymer are used. Examples of the silicone oil include dimethyl silicone oil, phenylmethyl silicone oil, alkyl silicone oil, fluorosilicone oil, tetramethyltetraphenyltrisiloxane, and modified silicone oil. Specific examples of the fluoropolymer include polytetrafluoro Examples thereof include ethylene and vinylidene fluoride copolymers. Among them, dimethyl silicone oil, phenylmethyl silicone oil, alkyl silicone oil, polytetrafluoroethylene, and vinylidene fluoride copolymer are preferable. In addition, higher fatty acid amides are also effective as other lubricants. Specifically, saturated fatty acid amides such as lauric acid amide, palmitic acid amide, stearic acid amide, and behemic acid amide; unsaturated fatty acid amides such as erucic acid amide, oleic acid amide, brassic acid amide, and elaidic acid amide; And bis fatty acid amides such as methylene bis stearic acid amide, methylene bis oleic acid amide, ethylene bis stearic acid amide, and ethylene bis oleic acid amide; Of these, erucic acid amide, oleic acid amide, ethylenebisoleic acid amide and the like are preferable.

  The vibration damping composition according to the present invention includes a syndiotactic α-olefin copolymer (A), an olefin thermoplastic elastomer (B), a polyolefin resin (C) used as necessary, and, if necessary, It is obtained by mixing a softener and / or an inorganic filler and / or additives blended in the above, and then dynamically heat-treating them as described above.

The vibration-damping molded body according to the present invention can be obtained by molding the vibration-damping composition described above. The molding is performed by a known method such as injection molding, various types of extrusion molding, compression molding, calendar molding, or vacuum molding.
In that case, the shape and size of the molded product are not particularly limited.

  Moreover, it can also be made to foam by a well-known method using a chemical foaming agent or a physical foaming agent at the time of shaping | molding, and a foamed molded object can also be obtained. As the foaming agent, a known chemical foaming agent or a known physical foaming agent such as carbon dioxide gas, nitrogen gas, or water can be used. The thickness of the sheet when foamed may be thicker than when not foamed.

  The molded body obtained by the above-described molding can be used alone, or can be used by being laminated with another material serving as a base material. Lamination is usually carried out via an adhesive, but in the case of lamination with polyethylene or polypropylene, lamination by thermal fusion is possible without using an adhesive.

  The vibration-damping composition and molded product of the present invention are a vibration-damping / sound-absorbing material and a vibration-damping / sound-absorbing part for automobiles, railways, airplanes, etc. Vibration control of various precision equipment. Used for sound absorbing parts.

  The vibration damping composition as described above is not only excellent in vibration damping properties, but also excellent in sound absorption, less environmental impact, excellent moldability, heat resistance, flexibility and rubber elasticity, no stickiness, Furthermore, it is excellent in durability.

[Example]
(Polymerization Example 1; polymerization of syndiotactic propylene / butene / ethylene random copolymer (A-1))
A 2000 ml polymerization apparatus sufficiently purged with nitrogen was charged with 100 ml of dry hexane, 480 g of 1-butene and triisobutylaluminum (1.0 mmol) at room temperature, and then the temperature of the polymerization apparatus was raised to 35 ° C. with propylene. Pressurized to 0.54 MPa and then pressurized to 0.62 MPa with ethylene. Thereafter, a toluene solution in which 0.005 mmol of diphenylmethylene (cyclopentadienyl) fluorenylzirconium dichloride and 1.5 mmol of methylaluminoxane (produced by Tosoh Finechem) in contact with aluminum was added to the inside of the polymerization vessel. Polymerization was performed for 5 minutes while maintaining a temperature of 35 ° C. and an ethylene pressure of 0.62 MPa, and 20 ml of methanol was added to terminate the polymerization. After depressurization, the polymer was precipitated from the polymerization solution in 2 L of methanol and dried under vacuum at 130 ° C. for 12 hours. The obtained polymer was 36.1 g. The composition of the polymer was such that the propylene content was 61.3 mol%, the ethylene content was 10.3 mol%, the 1-butene content was 28.4 mol%, the intrinsic viscosity [η] was 2.67 dl / g, The transition temperature Tg was −27.7 ° C., there was no melting peak, and the molecular weight distribution by GPC was 2.0. In ¹³ C-NMR measured with 1,2,4-trichlorobenzene solution, the total absorption intensity at which the absorption of the methyl group of the propylene unit is observed at about 20.0 to 21.0 ppm based on tetramethylsilane is propylene. It was 0.8 with an absorption intensity of about 19.0 to 22.0 ppm attributed to methyl.

(Polymerization Example 2; polymerization of syndiotactic propylene / ethylene random copolymer (A-2))
750 ml of heptane was added at room temperature to a 1.5 liter autoclave that had been dried under reduced pressure and purged with nitrogen, and then a 1.0 mmol / ml toluene solution of triisobutylaluminum converted to aluminum atoms, the amount was 0.3 0.3 ml was added so that it might become a millimol, and 50.7 liters (25 degreeC, 1 atmosphere) of propylene was charged with stirring, temperature rising was started, and it reached 30 degreeC. Thereafter, the inside of the system was pressurized to 5.5 kg / cm ² G with ethylene, and a heptane solution of diphenylmethylene (cyclopentadienyl) (fluorenyl) zirconium dichloride synthesized by a known method (0.0002 mM / ml). And 3.75 ml of triphenylcarbenium tetra (pentafluorophenyl) borate in toluene (0.002 mM / ml) were added to start copolymerization of propylene and ethylene. The catalyst concentration at this time was 0.001 mmol / liter of diphenylmethylene (cyclopentadienyl) (fluorenyl) zirconium dichloride and 0.004 mmol / liter of triphenylcarbenium tetra (pentafluorophenyl) borate relative to the total system. Liters.

During the polymerization, ethylene was continuously supplied to maintain the internal pressure at 5.5 kg / cm ² G. 30 minutes after starting the polymerization, the polymerization reaction was stopped by adding methyl alcohol. After depressurization, the polymer solution is taken out, and the polymer solution is washed with a ratio of 1: 1 of “an aqueous solution in which 5 ml of concentrated hydrochloric acid is added to 1 liter of water” to remove the catalyst residue. The water phase was transferred. After this catalyst mixed solution was allowed to stand, the aqueous phase was separated and removed, and further washed twice with distilled water, and the polymerization liquid phase was separated into oil and water. Subsequently, the polymer liquid phase separated from oil and water was brought into contact with 3 times the amount of acetone under strong stirring to precipitate a polymer, and then sufficiently washed with acetone, and the solid part (copolymer) was collected by filtration. It dried for 12 hours at 130 degreeC and 350 mmHg under nitrogen circulation.

  The propylene / ethylene copolymer obtained as described above has an intrinsic viscosity [η] measured in decalin at 135 ° C. of 2.4 dl / g, an SP value of 0.94, and a glass transition temperature of − It was 28 ° C., the ethylene content was 24 mol%, and the molecular weight distribution (Mw / Mn) measured by GPC was 2.9.

  30 parts by weight of isotactic polypropylene (a-1), an oil-extended product of ethylene / propylene / 5-ethylidene-2-norbornene copolymer rubber (EPDM (b-1)) (oil content 28.6% by weight, oil: Mineral oil-based paraffin oil), Mooney viscosity ML1 + 4 (100 ° C.) 80, ethylene content 79 mol%, iodine value 11) pellets 70 parts by weight and 2,5-dimethyl-2,5 as a crosslinking agent (POX) -Di- (tert-butylperoxy) hexane (0.2 parts by weight) and divinylbenzene (DVB) (0.3 parts by weight) as a crosslinking aid were stirred and mixed with a batch-type high-speed mixer, and then the two axes set at a maximum temperature of 230 ° C. Dynamic heat treatment was performed with an extruder to obtain pellets of the olefin-based thermoplastic elastomer (B-1). Batch type high-speed mixer using 30 parts by weight of the pellets of the olefinic thermoplastic elastomer (B-1) and 70 parts by weight of the syndiotactic propylene / butene / ethylene random copolymer (A-1) obtained in Polymerization Example 1. Then, the mixture was kneaded with a twin-screw extruder set at a maximum temperature of 230 ° C. to obtain a vibration damping composition 1.

  A flat plate of 150 mm × 120 mm × 3 mmt was produced from the obtained pellets by injection molding set at a cylinder temperature of 220 ° C., and the sound absorption coefficient was measured based on ASTM E 1050. The sound absorption coefficient was 0.072 at 2500 Hz and 0.092 at 5000 Hz.

  Further, rubber elasticity was evaluated by punching out a JIS No. 3 dumbbell from a 2 mm thick flat plate produced in the same manner and measuring the permanent elongation. Permanent elongation was 15%.

<Measurement method of permanent elongation>
Two marked lines at 2 cm intervals in the center of the dumbbell were attached and stretched at 23 ° C. until the distance between marked lines became 4 cm and fixed. After 10 minutes, the fixation was released, and further 10 minutes, the distance between the marked lines was measured, and the permanent elongation was calculated.
Permanent elongation = (distance between marked lines after 10 minutes of fixed release-2 cm) / 2 cm x 100 (%)

  Syndiotactic propylene / butene / ethylene random copolymer (A-1) 65 parts by weight, pellets of olefinic thermoplastic elastomer (B-1) 25 parts by weight, syndiotactic polypropylene 5 parts by weight, polybutene-1 homopolymer A damping composition 2 was obtained in the same manner as in Example 1 from 5 parts by weight. Further, the sound absorption coefficient and permanent elongation were measured in the same manner as in Example 1. The sound absorption coefficient was 0.075 at 2500 Hz, 0.095 at 5000 Hz, and the permanent elongation was 17%.

  In the same manner as in Example 1, 50 parts by weight of the syndiotactic propylene / ethylene random copolymer (A-2) and 50 parts by weight of the olefin-based thermoplastic elastomer (B-1) pellets obtained in Polymerization Example 2 were used. A vibratory composition 3 was obtained. Further, the sound absorption coefficient and permanent elongation were measured in the same manner as in Example 1. The sound absorption coefficient was 0.062 at 2500 Hz, 0.058 at 5000 Hz, and the permanent elongation was 20%.

[Comparative Example 1]
The sound absorption coefficient and permanent elongation of the olefinic thermoplastic elastomer (B-1) were measured in the same manner as in Example 1. The sound absorption coefficient was 0.038 at 2500 Hz, 0.040 at 5000 Hz, and the permanent elongation was 13%.

[Comparative Example 2]
The sound absorption coefficient and permanent elongation of the asphalt damping floor material (3 mmt) were measured in the same manner as in Example 1. The sound absorption rate was 0.060 at 2500 Hz and 0.058 at 5000 Hz. The permanent elongation broke during the stretching process and could not be measured.

Claims (4)

A vibration-damping composition comprising a syndiotactic α-olefin copolymer (A) and an olefin thermoplastic elastomer (B) comprising polyolefin resin (a) and ethylene copolymer rubber (b) as essential components. object.
Here, the syndiotactic α-olefin copolymer (A) is:
In ¹³ C-NMR measured with a 1,2,4-trichlorobenzene solution, the total absorption intensity at which the absorption of methyl groups of propylene units is observed at about 20.0 to 21.0 ppm based on tetramethylsilane is propylene. An absorption intensity of about 19.0 to 22.0 ppm attributed to methyl is 0.5 or more,
(A-1) a repeating unit derived from propylene;
(A-2) a repeating unit derived from ethylene;
(A-3) a repeating unit derived from at least one olefin selected from olefins having 4 to 20 carbon atoms, and, if necessary,
(A-4) consisting of a repeating unit derived from at least one polyene selected from conjugated polyenes and non-conjugated polyenes,
When the total amount of the unit (a-1), the unit (a-2) and the unit (a-3) is 100 mol%, the unit (a-1) is 30 to 78 mol%, the unit (a -2) containing 1 to 30 mol% of units and 1 to 50 mol% of units (a-3) (provided that the total amount of (a-2) units and (a-3) units is from 22 70 mol%), and the total amount of the (a-1) unit, (a-2) unit and (a-3) unit is 100 mol%, and the (a-4) unit is 0 to 30 mol%. And is substantially a syndiotactic structure.   In addition to the syndiotactic α-olefin copolymer (A), the olefin thermoplastic elastomer (B) containing the polyolefin resin (a) and the ethylene copolymer rubber (b) as essential components, syndiotactic 2. The control according to claim 1, comprising at least one polyolefin resin (C) selected from polypropylene (c-1), isotactic polypropylene (c-2), and polybutene (c-3). Tremor composition.   The syndiotactic α-olefin copolymer (A) does not have a melting peak measured by a differential scanning calorimeter (DSC) and has an intrinsic viscosity [η] measured in decalin at 135 ° C. of 0. The vibration-damping composition according to any one of claims 1 to 2, which is in a range of 01 to 10 dl / g, has a molecular weight distribution by GPC of 5 or less, and has a glass transition temperature Tg of -5 ° C or less. A vibration-damping molded article obtained by molding the vibration-damping composition according to any one of claims 1 to 3.