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EP-4735270-A1 - RUBBER COMPOSITION COMPRISING A HYDROCARBON RESIN OBTAINED FROM RUBBER CHIPS

EP4735270A1EP 4735270 A1EP4735270 A1EP 4735270A1EP-4735270-A1

Abstract

The invention relates to a tire for a vehicle, the tread of which comprises a rubber composition based on at least one elastomer matrix comprising at least (50) phr of a butadiene copolymer, a reinforcing filler, a crosslinking system, and a hydrocarbon resin based on a fraction resulting from the pyrolysis of a feedstock comprising rubber chips, the boiling point at atmospheric pressure of said fraction being in the range of 140 to 280°C.

Inventors

  • SUTTER, MARC
  • TOULEMONDE, Paul-Aymé

Assignees

  • COMPAGNIE GENERALE DES ETABLISSEMENTS MICHELIN

Dates

Publication Date
20260506
Application Date
20240625

Claims (9)

  1. [Claim 1] A vehicle tire, the tread of which comprises a rubber composition based on at least one elastomeric matrix comprising at least 50 pce of a butadiene copolymer, a reinforcing filler, a crosslinking system and a hydrocarbon resin based on a cut resulting from the pyrolysis of a filler comprising rubber chips, the boiling point at atmospheric pressure of said cut being in the range from 140 to 280°C.
  2. [Claim 2] Bandage according to the preceding claim in which the reinforcing filler comprises from 10 to 150 pce, preferably from 50 to 130 pce of silica.
  3. [Claim 3] Bandage according to any one of the preceding claims in which the butadiene copolymer has a glass transition temperature Tg of less than -20°C, preferably between -20°C and -110°C.
  4. [Claim 4] A tire according to any preceding claim wherein the rubber composition comprises at least 70 phr, preferably at least 90 phr of at least one butadiene copolymer, preferably a butadiene - styrene copolymer.
  5. [Claim 5] Bandage according to any one of the preceding claims in which the hydrocarbon resin has the following characteristics: ■ • a glass transition temperature (denoted Tg) ranging from 20°C to 140°C; • a number-average molar mass of less than 5000 g/mol • a dispersity D less than 3 • An aromatic proton rate, determined by 1H NMR, between 0.5%mol and 50%mol • A rate of aliphatic protons, determined by 1H NMR, between 50%mol and 99.5%mol • A rate of ethylenic protons, determined by 1H NMR, less than or equal to 10%mol The sum of the aromatic, aliphatic and ethylenic proton rates being equal to 100%.
  6. [Claim 6] Bandage according to the preceding claim in which the aromatic proton content of the hydrocarbon resin, determined by 1H NMR, is between 2 mol% and 30 mol%, preferably is between 2 mol% and 20 mol% and very preferably is between 5 mol% and 15 mol%.
  7. [Claim 7] A tire according to any one of the preceding claims, in which the hydrocarbon resin is obtained by a process comprising at least ■ a) A step of pyrolysis of a charge comprising rubber chips making it possible to obtain at least one pyrolysis oil b) A step of separation of the pyrolysis oil into at least one raffinate, an intermediate fraction and an extract, the intermediate fraction having a boiling point at atmospheric pressure in the range from 140 to 280°C and comprising at most 10% by weight of heteroatoms c) A step of synthesis of resins comprising a polymerization section supplied with the intermediate fraction from step b) and producing a polymerized effluent d) A treatment step comprising a section for separation of the polymerized effluent from step c) into a solvent-rich effluent and a resin-rich effluent, and a drying section supplied with the resin-rich effluent in order to produce the hydrocarbon resin.
  8. [Claim 8] Bandage according to the preceding claim in which the rubber chips fed in step a) of the process comprise at least 50 pce of diene elastomer, preferably at least 60 pce of diene elastomer.
  9. [Claim 9] Bandage according to any one of the preceding claims in which the intermediate fraction constituting the cut at the base of the hydrocarbon resin has a boiling point at atmospheric pressure in the range from 150 to 280°C and preferably from 150 to 260°C.

Description

Rubber composition comprising a hydrocarbon resin obtained from rubber chips Technical field of the invention The present invention relates to the field of rubber compositions, in particular rubber compositions for pneumatic tires. Prior art Pneumatic tires, and more generally rubber articles such as conveyor belts and non-pneumatic tires, are complex objects made up of a multitude of components. For example, a pneumatic tire is made up of more than 200 different raw materials. The challenges in terms of pressure on renewable and fossil resources are such that it is essential to make the best possible use of the resources that constitute used rubber articles. However, the recycling of materials from used rubber articles, such as used tires into new tires, is still limited, in particular due to the major impact of the constituents on the performance of the tire. Indeed, the recycling of materials can have a negative overall environmental impact due to the degradation of the performance of tires using these materials. There is therefore a strong need for processes for recovering end-of-life rubber articles in order to produce raw materials whose use will not degrade the performance of the tires, thus leading to an overall lower environmental impact. Much research has been conducted in this field, particularly on the recovery of oils from the pyrolysis of tire waste. Thus, documents EP 0928817, WO 2013/170358 and JP2017/008214 teach the production of tire grade carbon black from the pyrolysis of tire tire chips. Other research focuses on the valorization of intermediate products. WO 90/14409 focuses on the separation of pyrolysis oils from tire waste by distillation in order to recover valuable chemical compounds, in particular limonene, the distillation being carried out in such a way as to concentrate the species of commercial interest. The article "Production of dldimonene by vacuum pyrolysis of used tires" teaches that the amount of limonene in pyrolysis oils from tire tire chips can be increased by adjusting the temperature of the pyrolysis step and by minimizing the residence time of the vapor phase in the reactor. The document "A review of dipentene (dldimonene) production from waste tire pyrolysis” (Danon et al., Journal of Analytical and Applied Pyrolysis 112 (2015) 1—13) also discusses the production of dipentene from waste tires. None of these papers address the further use of these products. The paper “Thermal depolymerization and pyrolysis of cis-l,4-polyisoprene ■ preparation of liquid polyisoprene and terpene resin” (Cataldo, Journal of Analytical and Applied Pyrolysis 44 (1998) 121–130) discusses the production of resins from the depolymerization product of pure isoprene, whether natural or synthetic. However, the depolymerization of waste tires leads to many by-products that are not present during the depolymerization of pure polyisoprene, which have a potentially deleterious effect on resin production. Documents WO2022/101562 and WO2022/101563 describe the synthesis of resins from rubber chips that can be used in the manufacture of new tires without impacting their performance. However, these documents are silent on the specific uses of the resins produced. Continuing its research, the applicant discovered that a vehicle tire tread comprising a rubber composition including a resin produced from rubber chips exhibits improved dry grip performance and stiffness without degrading rolling resistance performance. Detailed description of the invention The invention relates to at least one vehicle tire, the tread of which comprises a rubber composition based on at least one elastomeric matrix comprising at least 50 pce of a butadiene copolymer, a reinforcing filler, a crosslinking system and a hydrocarbon resin based on a cut resulting from the pyrolysis of a filler comprising rubber chips, the boiling point at atmospheric pressure of said cut being in the range from 140 to 280°C. Preferably, the reinforcing filler comprises from 10 to 150 pce, preferably from 50 to 130 pce of silica. Preferably, the butadiene copolymer has a glass transition temperature Tg of less than -20°C, preferably between -20°C and -110°C. Preferably, the rubber composition comprises at least 70 pce, preferably at least 90 pce of at least one butadiene copolymer, preferably a butadiene-styrene copolymer. Preferably, the hydrocarbon resin has the following characteristics: ■ • a glass transition temperature (denoted Tg) ranging from 20°C to 140°C • a number-average molar mass of less than 5000 g/mol • a dispersity D less than 3 • An aromatic proton rate, determined by 1H NMR, between 0.5%mol and 50%mol J • A rate of aliphatic protons, determined by 1H NMR, between 50%mol and 99.5%mol J • A rate of ethylenic protons, determined by 1H NMR, less than or equal to 10%mol The sum of the rates of aromatic, aliphatic and ethylenic protons being equal to 100%. Preferably, the aromatic proton content of the hydrocarbon resin, determin