Adhesion aging protection in corded rubber articles

{
  "publication_number": "US10737882B2",
  "country": "US",
  "kind": "B2",
  "title": "Adhesion aging protection in corded rubber articles",
  "abstract": "A conveyor belt including a carry cover layer, a reinforcement layer which is situated below the carry cover layer, and a pulley cover layer which is situated below the reinforcement layer, where the reinforcement layer is comprised of steel cordage and rubber matrix, and wherein the rubber matrix includes zinc oxide in an amount greater than 5 phr and a cobalt derivative in an amount of 1 phr or greater. In some cases, the rubber matrix includes zinc oxide in an amount of 11 phr or greater, or even in an amount of 16 phr or greater. In some cases, the rubber matrix includes the cobalt derivative in an amount of 2 phr or greater, or even in an amount of from 3 phr to 4 phr. In some aspects, the rubber matrix is devoid of lead oxide.",
  "claims": [
    "1. A conveyor belt which is comprised of a carry cover layer, a reinforcement layer which is situated below the carry cover layer, and a pulley cover layer which is situated below the reinforcement layer, wherein the reinforcement layer is comprised of steel cordage and a rubber matrix, wherein the rubber matrix comprises silica and styrene resin emulsion, wherein the rubber matrix further comprises zinc oxide in an amount greater than 16 phr and a cobalt derivative in an amount of 3 phr or greater, and wherein the steel cordage has a pullout force value of at least 123 N after exposure to autoclave water steam for 5 days/105° C.",
    "2. The conveyor belt according to claim 1 wherein the rubber matrix comprises the zinc oxide in an amount of 17 phr or greater.",
    "3. The conveyor belt according to claim 1 wherein the rubber matrix comprises the cobalt derivative in an amount of 3.5 phr or greater.",
    "4. The conveyor belt according to claim 1 wherein the cobalt derivative is cobalt-boron-2-ethyl-hexanoate/neodecanoate.",
    "5. The conveyor belt according to claim 1 wherein the cobalt derivative is cobalt neodecanoate.",
    "6. The conveyor belt according to claim 1 wherein one or more of the carry cover layer, pulley cover layer, or rubber matrix comprises at least one rubbery polymer selected from the group consisting of styrene-butadiene rubber, synthetic polyisoprene rubber, nitrile rubber, isoprene-butadiene rubber, polybutadiene rubber styrene-isoprene-butadiene rubber, chloroprene rubber and ethylene-propylene-diene rubber.",
    "7. The conveyor belt according to claim 1 wherein the carry cover layer includes zinc oxide at a level of greater than 16 phr and the cobalt derivative in an amount of 3 phr or greater.",
    "8. The conveyor belt according to claim 1 wherein the pulley cover layer includes zinc oxide at a level of greater than 16 phr and the cobalt derivative in an amount of 3 phr or greater.",
    "9. The conveyor belt according to claim 1 wherein one or more of the carry cover layer or the pulley cover layer, includes zinc oxide at a level of greater than 16 phr and the cobalt derivative in an amount of 3 phr or greater.",
    "10. The conveyor belt according to claim 1 wherein one or more of the carry cover layer, the pulley cover layer, or the rubber matrix is devoid of lead oxide.",
    "11. A conveyor belt which is comprised of a carry cover layer, a reinforcement layer which is situated below the carry cover layer, and a pulley cover layer which is situated below the reinforcement layer, wherein the reinforcement layer is comprised of zinc coated steel cords and a rubber matrix, wherein the rubber matrix comprises silica and styrene resin emulsion, wherein the rubber matrix further comprises zinc oxide in an amount greater than 16 phr and a cobalt derivative in an amount of 3 phr or greater, and wherein the steel cordage has a pullout force value of at least 123 N after exposure to autoclave water steam for 5 days/105° C., a rubber matrix, wherein the rubber matrix comprises silica and styrene resin emulsion, and wherein the rubber matrix further comprises zinc oxide in an amount greater than 16 phr and a cobalt derivative in an amount of 3 phr or greater; and wherein the steel cordage has a pullout force value of at least 123 N after exposure to autoclave water steam for 5 days/105° C.",
    "12. The conveyor belt according to claim 11 wherein the rubber matrix comprises the zinc oxide in an amount of 17 phr or greater and the cobalt derivative in an amount of 3.5 phr or greater.",
    "13. The conveyor belt according to claim 11 wherein the cobalt derivative is cobalt-boron-2-ethyl-hexanoate/neodecanoate.",
    "14. The conveyor belt according to claim 11 wherein the cobalt derivative is cobalt neodecanoate.",
    "15. The conveyor belt according to claim 11 wherein the rubber matrix is devoid of lead oxide."
  ],
  "description_excerpt": "The field to which the disclosure generally relates is rubber articles containing metal reinforcements therein, and in particular, conveyor belts having zinc coated steel reinforcement cords therein.\n\nThis section provides background information to facilitate a better understanding of the various aspects of the disclosure. It should be understood that the statements in this section of this document are to be read in this light, and not as admissions of prior art.\n\nMany rubber articles, such as conveyor belts, automobile tires, hoses, power train belts, e.g., transmission belts, and the like, are usually reinforced with fibrous or metal cords. In all such instances, the fiber or metal cord must be firmly bonded to the rubber. This is so whether the fiber or cord is a natural or synthetic polymer, or metallic, and whether the rubbers are natural or synthetic.\n\nConventional conveyor belts which are used in heavy duty applications are typically comprised of a cured rubber or polyvinyl chloride (PVC) based material as a top layer, a cured rubber or PVC based material as a bottom layer, and one or more reinforcement layers (a carcass) disposed between the top layer and the bottom layer. The cured rubber or polyvinyl chloride based material may also serve to adhere various components of the reinforcing carcass. For example, individual layers and reinforcing elements included in the carcass may be encapsulated in a matrix of polymeric elastomeric resin, such as a polyvinylchloride based material.",
  "cpc": [
    "B65G 15/34",
    "B65G 15/36",
    "B65G 15/38",
    "C08K 13/02",
    "C08K 2003/2296",
    "C08K 3/04",
    "C08K 3/22",
    "C08K 3/36",
    "C08K 5/0016",
    "C08K 5/098",
    "C08L 9/06"
  ],
  "ipc": [
    "B65G 15/34",
    "B65G 15/36",
    "C08K 13/02",
    "C08K 3/22",
    "C08K 5/098"
  ],
  "assignees": [
    "ContiTech USA LLC"
  ],
  "inventors": [
    "Katja Henning",
    "Stefan Sostmann",
    "Stavros Podias",
    "Thomas George Burrowes"
  ],
  "filing_date": "2019-04-25",
  "publication_date": "2020-08-11",
  "grant_date": "2020-08-11",
  "priority_date": "2018-03-23",
  "application_number": "US-201916393995-A",
  "family_id": "67984711",
  "cited_by_count": 1,
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}