Rubber composition for conveyor belt, and conveyor belt

{
  "publication_number": "US10442915B2",
  "country": "US",
  "kind": "B2",
  "title": "Rubber composition for conveyor belt, and conveyor belt",
  "abstract": "A rubber composition capable of forming a conveyor belt. The rubber composition for a conveyor belt contains: rubber components including natural rubber and butadiene rubber; a vulcanizing agent; a vulcanization accelerator; carbon black; chlorinated paraffin; and antimony trioxide. A mass ratio of content of the natural rubber to content of the butadiene rubber (natural rubber content:butadiene rubber content) is 25:75 to 45:55.",
  "claims": [
    "1. A rubber composition for a conveyor belt comprising: rubber components including natural rubber and butadiene rubber; a vulcanizing agent; a vulcanization accelerator; carbon black; chlorinated paraffin; antimony trioxide, and at least one hydrazide compound, wherein a mass ratio of content of the natural rubber to content of the butadiene rubber is from 25:75 to 45:55, and content of the hydrazide compound as a proportion, by mass, relative to content of the chlorinated paraffin is 0.005 to 0.25.",
    "2. The rubber composition for a conveyor belt of claim 1, wherein the hydrazide compound is naphthoic hydrazide or a derivative thereof.",
    "3. The rubber composition for a conveyor belt of claim 1, wherein the chlorinated paraffin has a content of 5 parts by mass to 50 parts by mass relative to 100 parts by mass of the rubber components.",
    "4. The rubber composition for a conveyor belt of claim 1, wherein the hydrazide compound has a content of 0.1 parts by mass to 5 parts by mass relative to 100 parts by mass of the rubber components.",
    "5. The rubber composition for a conveyor belt of claim 1, wherein the chlorinated paraffin has a content of 10 parts by mass to 30 parts by mass relative to 100 parts by mass of the rubber components and the hydrazide compound has a content of 0.5 parts by mass to 3 parts by mass relative to 100 parts by mass of the rubber components.",
    "6. The rubber composition for a conveyor belt of claim 1 having a loss index of no greater than 0.110, the loss index being calculated from a storage modulus (E′) and a loss tangent tan δ at a strain of 2%, a frequency of 10 Hz, and a temperature of 20° C. according to: loss index=tan δ/E′ 1/3.",
    "7. The rubber composition for a conveyor belt of claim 1 having a tensile strength (Tb) of at least 14.0 MPa as measured in accordance with JIS K 6251.",
    "8. A conveyor belt in which the rubber composition for a conveyor belt of claim 1 is used.",
    "9. The rubber composition for a conveyor belt of claim 1, wherein a total content of the natural rubber and the butadiene rubber among the rubber composition is at least 90 mass %."
  ],
  "description_excerpt": "This disclosure relates to a rubber composition for a conveyor belt, and a conveyor belt.\n\nTransporting equipment including a conveyor belt as a means for transporting items is used in various industrial fields such as the steel, coal, and cement industries. Such transporting equipment is commonly used in harsh environments and is often used to transport high-temperature articles. The conveyor belt of the transporting equipment is therefore required to have not only high strength as a rubber article, but also high flame retardance. On the other hand, there has recently been strong demand for transporting equipment having improved fuel efficiency, and thus there is need for a conveyor belt having an excellent low loss property.\n\nThe use of mainly natural rubber and styrene-butadiene rubber (SBR) as rubber components to provide a rubber article with high strength and flame retardance is a known technique. This technique is also applicable for conveyor belts. For example, PTL 1 discloses that by using mainly natural rubber and styrene-butadiene rubber as rubber components and by compounding a suitable flame retardant, a rubber composition for a conveyor belt having improved impact resistance can be obtained, while also ensuring flame retardance.\n\nPTL 1: JP 2012-180475 A\n\nHowever, a conveyor belt produced using the rubber composition described above in which mainly natural rubber and styrene-butadiene rubber are used as rubber components suffers from a problem of having an inadequate low loss property.",
  "cpc": [
    "C08L 9/00",
    "B65G 15/32",
    "C08K 3/04",
    "C08K 3/06",
    "C08K 3/22",
    "C08K 5/25",
    "C08K 5/31",
    "C08K 5/47",
    "C08L 2201/02",
    "C08L 7/00",
    "C08L 91/00",
    "C08L 91/06"
  ],
  "ipc": [
    "B65G 15/32",
    "C08K 3/04",
    "C08L 9/00",
    "C08L 91/06"
  ],
  "assignees": [
    "Bridgestone Corp"
  ],
  "inventors": [
    "Yasuhiko Matsumuro",
    "Toshihiko KURATA"
  ],
  "filing_date": "2015-10-05",
  "publication_date": "2019-10-15",
  "grant_date": "2019-10-15",
  "priority_date": "2014-10-07",
  "application_number": "US-201515514887-A",
  "family_id": "55652855",
  "cited_by_count": 0,
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}