Thermoplastic resin composition having high durability

{
  "publication_number": "US9862825B2",
  "country": "US",
  "kind": "B2",
  "title": "Thermoplastic resin composition having high durability",
  "abstract": "The thermoplastic resin composition according to the present invention includes a thermoplastic resin (A), and a modified ethylene copolymer (B) dispersed and contained therein, wherein the modified ethylene copolymer (B) in the thermoplastic resin composition has an average dispersed particle aspect ratio of 1 to 3.5, and an average dispersed particle diameter of not more than 3 μm. The modified ethylene copolymer (B) is preferably a copolymer, modified with an unsaturated carboxylic acid or a derivative thereof, of ethylene with at least one monomer component selected from the group consisting of (i) olefin components except for ethylene, (ii) diene components and (iii) ester components having an ethylenically unsaturated group.",
  "claims": [
    "1. A thermoplastic resin composition is a thermoplastic elastomer alloy, wherein the thermoplastic elastomer alloy comprises a polyurethane-based thermoplastic elastomer (A11) and a modified ethylene-propylene-diene copolymerized rubber (B1), and is obtained by dispersing the modified ethylene-propylene-diene copolymerized rubber (B1) into the polyurethane-based thermoplastic elastomer (A11), wherein the polyurethane-based thermoplastic elastomer (A11) is at least one selected from the group consisting of adipate-based thermoplastic polyurethanes, caprolactone-based thermoplastic polyurethanes, and polytetramethylene ether glycol-based thermoplastic polyurethanes, and forms a continuous phase in the thermoplastic elastomer alloy, wherein the modified ethylene-propylene-diene copolymerized rubber (B1) is a maleic anhydride-modified ethylene-propylene-diene copolymerized rubber, and forms a disperse phase in the thermoplastic elastomer alloy, wherein a content rate of the modified ethylene-propylene-diene copolymerized rubber (B1) is 30 to 60 wt % based on the total content of the polyurethane-based thermoplastic elastomer (A11) and the modified ethylene-propylene-diene copolymerized rubber (B1).",
    "2. The thermoplastic resin composition according to claim 1, wherein the modified ethylene-propylene-diene copolymerized rubber (B1) in the thermoplastic elastomer alloy has an average dispersed particle aspect ratio of 1 to 3.5 and an average dispersed particle diameter of not more than 3 μm.",
    "3. The thermoplastic resin composition according to claim 1, wherein a content rate of the modified ethylene-propylene-diene copolymerized rubber (B1) is 50 to 60 wt % based on the total content of the polyurethane-based thermoplastic elastomer (A11) and the modified ethylene-propylene-diene copolymerized rubber (B1).",
    "4. The thermoplastic resin composition according to claim 2, wherein a content rate of the modified ethylene-propylene-diene copolymerized rubber (B1) is 50 to 60 wt % based on the total content of the polyurethane-based thermoplastic elastomer (A11) and the modified ethylene-propylene-diene copolymerized rubber (B1).",
    "5. The thermoplastic resin composition according to claim 1, wherein the modified ethylene-propylene-diene copolymerized rubber (B1) in the thermoplastic elastomer alloy has an average dispersed particle aspect ratio of 1.08 to 3.5 and an average dispersed particle diameter of not more than 3 μm."
  ],
  "description_excerpt": "The present invention relates to a thermoplastic resin composition, particularly to a thermoplastic resin composition having durability, particularly, high bending fatigue resistance, and a molded article formed from the thermoplastic resin composition.\n\nThermoplastic polyurethanes (TPU) as urethanic thermoplastic elastomers (TPE), since having good elasticity and being excellent in abrasion resistance, mechanical strength, chemical resistance and the like, are used as materials of belt products, tubes, hoses and other various types of molded articles.\n\nHowever, molded articles formed from thermoplastic polyurethanes, if used for a long time in the state of being continuously or intermittently subjected to a large load, come to be damaged and broken in some cases. For example, if belt products formed from thermoplastic polyurethanes are used for a long time, belt members and the like abrade and crack in some cases.\n\nJapanese Patent Laid-Open No. 11-349804 discloses a blend containing a thermoplastic polyurethane and an ethylene-propylene rubber (EPM) and/or a modified ethylene-propylene rubber (modified EPM) in a proportion of the former/the latter (in weight ratio)=3/1 to 999/1. However, molded articles using the blend, if used for a long time under a heavy load state, cannot always be said to have sufficient durability, particularly, sufficient bending fatigue resistance.",
  "cpc": [
    "C08L 75/06",
    "B65G 15/32",
    "C08G 18/4277",
    "C08G 18/4854",
    "C08G 2350/00",
    "C08G 2380/00",
    "C08G 2410/00",
    "C08G 69/40",
    "C08G 69/44",
    "C08J 5/00",
    "C08L 101/00",
    "C08L 2207/04",
    "C08L 23/0869",
    "C08L 23/16",
    "C08L 23/26",
    "C08L 53/025",
    "C08L 67/02",
    "C08L 67/025",
    "C08L 75/04",
    "C08L 75/12",
    "C08L 77/02",
    "C08L 77/06",
    "C08L 77/12",
    "F16G 1/14",
    "Y10T 428/1372"
  ],
  "ipc": [
    "B65G 15/32",
    "C08G 69/40",
    "C08G 69/44",
    "C08L 23/08",
    "C08L 23/16",
    "C08L 23/26",
    "C08L 53/02",
    "C08L 67/02",
    "C08L 75/04",
    "C08L 75/06",
    "C08L 75/12",
    "C08L 77/02",
    "C08L 77/06",
    "C08L 77/12",
    "F16G 1/14"
  ],
  "assignees": [
    "Nitta Corp"
  ],
  "inventors": [
    "Toshiaki Kasazaki",
    "Takahiko Yoshida",
    "Shoji Shimizu",
    "Shinsuke Uegaki",
    "Yoko Onishi"
  ],
  "filing_date": "2012-03-29",
  "publication_date": "2018-01-09",
  "grant_date": "2018-01-09",
  "priority_date": "2011-03-31",
  "application_number": "US-201214007931-A",
  "family_id": "46931605",
  "cited_by_count": 3,
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    "JP2001247760A",
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  ]
}