# US 9,434,836 B2 · EPDM composition for torsional damper

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- Number: US 9,434,836 B2
- Document ID: US9434836B2
- Status: Granted
- Kind: B2
- Application number: 14/652,064
- Filed: 2014-06-17
- Published: 2016-06-23
- Granted: 2016-09-06
- Earliest claimed: 2013-07-25
- Assignees: Nok Corporation
- Applicants: NOK Corporation
- Inventors: Tetsuro Negami
- Web page: https://patentgrep.com/patent/US9434836B2

## CPC

- C08L 23/16: Ethylene-propylene or ethylene-propylene-diene copolymers
- C08K 3/04: Carbon
- C08L 9/00: Compositions of homopolymers or copolymers of conjugated diene hydrocarbons
- C08L 23/00: Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
- C08L 23/18: Homopolymers or copolymers of hydrocarbons having four or more carbon atoms
- C08L 45/00: Compositions of homopolymers or copolymers of compounds having no unsaturated aliphatic radicals in side chain, and having one or more carbon-to-carbon double bonds in a carbocyclic or in a heterocyclic ring system; Compositions of derivatives of such polymers (of cyclic anhydrides or imides C08L35/00; of cyclic esters of polyfunctional acids C08L31/00)
- C08K 2201/006: Additives being defined by their surface area
- C08L 2205/025: containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure
- C08L 2205/03: containing three or more polymers in a blend
- C08L 2312/00: Crosslinking
- F16F 15/124: Elastomeric springs (F16F15/123, {F16F15/127} take precedence)
- C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06)
- C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09)
- F16F: SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION

## Abstract

An EPDM composition for a torsional damper. The EPDM composition is made of (a) an EPDM polymer, (b) liquid polyolefin oligomer, and (c) carbon black, the EPDM composition containing 100 parts by weight of EPDM polymer that is the EPDM polymer of (a) having a propylene content of 35 to 50 wt % in the total amount of ethylene and propylene, 5 to 30 parts by weight of liquid polyolefin oligomer that is the liquid polyolefin oligomer of (b) having a number average molecular weight Mn within a range of 3,000 to 4,000, and 10 to 120 parts by weight of carbon black that is the carbon black of (c) having a nitrogen adsorption specific surface area within a range of 100 to 150 m2/g, an iodine adsorption within a range of 110 to 160 mg/g, and a DBP oil absorption within a range of 70 to 135 cm3/100 g.

## Claims

### Claim 1

An EPDM composition for a torsional damper comprising:
(a) 100 parts by weight of an EPDM polymer having a propylene content of 35 to 50 wt % in the total amount of ethylene and propylene,
(b) 5 to 30 parts by weight of liquid polyolefin oligomer having a number average molecular weight Mn within a range of 3,000 to 4,000, and
(c) 10 to 120 parts by weight of carbon black having a nitrogen adsorption specific surface area within a range of 100 to 150 m2/g, an iodine adsorption within a range of 110 to 160 mg/g, and a DBP oil absorption within a range of 70 to 135 cm3/100 g.

### Claim 2 (depends on 1)

The EPDM composition for a torsional damper of claim 1, wherein the carbon black of (c) is at least any one selected from SAF carbon black, ISAF carbon black, or ISAF-LS carbon black.

### Claim 3 (depends on 1)

The EPDM composition for a torsional damper of claim 1, further comprising 1 to 20 parts by weight of aromatic modified terpene resin.

### Claim 4 (depends on 2)

The EPDM composition for a torsional damper of claim 2, further comprising 1 to 20 parts by weight of aromatic modified terpene resin.