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EP-4735518-A1 - PROCESS FOR THE PRODUCTION OF HYDROCARBON RESINS FROM POLYSTYRENE RESIDUDES

EP4735518A1EP 4735518 A1EP4735518 A1EP 4735518A1EP-4735518-A1

Abstract

The invention relates to a process for producing hydrocarbon resins from a feedstock of styrene compounds and a stream of aliphatic compounds comprising at least 5% by weight of bio-based terpene compounds.

Inventors

  • MAISONNEUVE, Lise
  • RIFFARD, Fanny
  • SUTTER, MARC

Assignees

  • COMPAGNIE GENERALE DES ETABLISSEMENTS MICHELIN

Dates

Publication Date
20260506
Application Date
20240625

Claims (15)

  1. [Claim 1] A process for producing hydrocarbon resins from a feedstock of styrenic compounds, said process comprising at least ■ a. A step of preparing the feedstock of styrenic compounds so as to be able to feed this feedstock into the pyrolysis step; b. A step of pyrolyzing the feedstock of styrenic compounds making it possible to obtain at least one gaseous effluent and one pyrolysis oil, said gaseous effluent comprising at least 20% by weight of aromatic compounds; c. A step of separating the gaseous effluent into at least one stream rich in light compounds, one stream rich in aromatic compounds and one stream rich in heavy compounds; d. A step of synthesizing resins comprising a polymerization section fed at least by a stream from step c) and by a stream of aliphatic compounds comprising at least 5% by weight of terpenic compounds of biosourced origin, followed by a finishing section and producing a polymerized effluent; e. A treatment step comprising a section for separating the polymerized effluent from step c) into a solvent-rich effluent and a resin-rich effluent, and a drying section fed with the resin-rich effluent in order to produce a stream of hydrocarbon resins.
  2. [Claim 2] A method according to the preceding claim in which the charge of styrenic compounds is a charge of styrenic compounds from plastic waste comprising at least 90% by weight of polystyrene.
  3. [Claim 3] Method according to any one of the preceding claims in which the terpene compounds are chosen from terpenes comprising at most 20 carbon atoms, preferably chosen from the compounds limonene, alpha-pinene, beta-pinene, myrcene, farnesene and their mixtures, preferably chosen from the compounds limonene, alpha-pinene, beta-pinene and their mixtures and preferably are limonene.
  4. [Claim 4] A method according to any preceding claim wherein the charge of styrenic compounds is gradually heated. during step a) at a temperature between 100°C and 300°C, preferably between 150°C and 300°C and more preferably between 200°C and 300°C.
  5. [Claim 5] A method according to any one of the preceding claims, in which the pyrolysis step comprises a pyrolysis reactor operated at a temperature ranging from 300°C to 900°C and preferably ranging from 300 to 800°C and a pressure ranging from 0.8 bar to 7.5 bar.
  6. [Claim 6] A method according to any preceding claim wherein the pyrolysis step involves a microwave pyrolysis step.
  7. [Claim 7] A process according to any preceding claim in which separation step c) is carried out by distillation.
  8. [Claim 8] Method according to the preceding claim in which, in step c), a first column fed with the gaseous effluent from step b) separates this effluent into a flow rich in light compounds and into a raffinate, the latter being separated by means of a second column into a flow rich in aromatic compounds and a flow rich in heavy compounds.
  9. [Claim 9] Process according to claim 7, in which step c) is carried out in a single distillation column operated at a pressure of between 0.1 and 2.0 bar, preferably between 0.5 and 1.5 bar and more preferably between 0.5 and 1.1 bar, the distillation column being supplied at the bottom of the column with at least the gaseous effluent from step b) and producing at the top of the column a flow rich in light compounds, at the bottom a flow rich in heavy compounds, and by a lateral draw-off a flow rich in aromatic compounds, said column having as its only heat supply said gaseous effluent from step b).
  10. [Claim 10] Method according to any one of the preceding claims, in which the mass ratio of flow from step b) to the flow of aliphatic compounds feeding step d) is adjusted so that the resin obtained has a molar ratio of aliphatic H to aromatic H ranging from 40/60 to 95/5, preferably ranging from 50/50 to 90/10, more preferably ranging from 55/45 to 90/10.
  11. [Claim 11] A method according to any preceding claim wherein the polymerization section of resin synthesis step d) is also supplied with a stream of solvent chosen from aliphatic, aromatic, halogenated solvents and their mixtures.
  12. [Claim 12] Process according to any one of claims 1 to 10 supplied solely by the feed of styrenic compounds and the flow of aliphatic compounds comprising at least 5% by weight of terpenic compounds of biosourced origin, the solvent necessary in step d) being provided by at least one flow from step c) and/or at least a fraction of the pyrolysis oil from step b).
  13. [Claim 13] Process according to the preceding claim in which at least a fraction of the pyrolysis oil from step b) feeds step d) of resin synthesis.
  14. [Claim 14] Process according to any one of the preceding claims, in which the polymerization section is operated at a temperature ranging from +20 to +90°C, with a residence time of between 0.5 h and 4 h, in the presence of 0.1% to 2% by weight of catalyst relative to the weight of monomers at the inlet of the polymerization section and a mass ratio of flow from step b) to the flow of terpene compounds of biosourced origin such that the rate of aromatic protons, determined by 1H NMR, is between 0.5 mol% and 99 mol%, preferably between 1 mol% and 50 mol%, preferably between 2 mol% and 40 mol%, preferably between 2 mol% and 30 mol% and the rate of aliphatic protons, determined by 1H NMR, is between 99.5 mol% and 1 mol%, preferably between 99% mol and 50% mol, preferably between 98% mol and 70% mol.
  15. [Claim 15] Hydrocarbon resin obtained from the process according to any one of the preceding claims, said resin having 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, preferably less than 4000 g/mol and more preferably less than 3000 g/mol; - a dispersity D of less than 3, preferably less than 2.5 and more preferably less than 2; - A rate of aromatic protons, determined by 1H NMR, between 0.5 mol% and 99 mol%, preferably between 1 mol% and 50 mol%, preferably between 2 mol% and 40 mol%, preferably between 2 mol% and 30 mol% and more preferably between 2 mol% and 20 mol%; - A rate of aliphatic protons, determined by 1H NMR, between 1% mol and 99.5% mol, preferably between 50% mol and 99% mol, preferably between 70% mol and 98% mol - A level of ethylenic protons, determined by 1H NMR, less than or equal to 10 mol%, preferably less than or equal to 5 mol%, preferably less than or equal to 4 mol%, the sum of the levels of aromatic, aliphatic and ethylenic protons being equal to 100%.

Description

Process for the production of hydrocarbon resins from polystyrene residues Technical field of the invention The present invention relates to the field of processes for producing hydrocarbon resins, in particular for rubber articles and in particular vehicle tires, from recycled residues. 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, including different families of elastomers, reinforcing fillers, oils, hydrocarbon resins. By hydrocarbon resin is meant a resin consisting of carbon and hydrogen. Within hydrocarbon resins, hydrocarbon resins having a high glass transition temperature (Tg) comprising both aliphatic functions and aromatic functions are used to shift the performance compromises of the mixtures, such as rolling resistance or grip. These resins make it possible, in particular, to modify the Tg of the mixture. Such resins having a high Tg are known from the state of the art and described, for example, in document WO2016/043851, US9139721 or FR2968006. The compatibility of resins with the elastomeric matrix, and in particular their ability to disperse correctly in the mixture, is essential for them to play their role correctly. The compatibility of the resin with an elastomeric matrix depends, among other things, on properties such as the glass transition temperature and the softening point of the resin, these properties being dependent on the molar mass, the nature and the ratio of aromatic units to aliphatic units of the resin (see for example J. Appl Polym. Sci 2022 139(15) 51950). It is therefore important to be able to vary these parameters in order to address the variety of elastomers used in rubber compositions. Such resins comprising aliphatic and aromatic units are well known in the state of the art, for example in document EP 0 936 229 which teaches the manufacture of hydrocarbon resins from aliphatic and aromatic monomers in cationic polymerization, from petroleum-based streams. While the performance of tires such as rolling resistance and wear resistance are key to limiting their environmental impact, it is also important to seek to limit as much as possible the use of fossil resources during the manufacture of rubber articles. Document US2013/0281611 describes a rubber composition for a tire that includes a plasticizer derived from the recycling of waste, the plasticizer being used here as a substitute for process oils. Documents WO2022/101562 and WO2022/101563 describe the production of hydrocarbon resins from residues from the pyrolysis of rubber chips. However, these documents do not address the problem of adjusting the microstructure of the resins, and in particular of adjusting the rate of aromatic and aliphatic monomers. Thus, an object of the present invention is to provide a process for producing resins that can be incorporated into a wide variety of elastomeric compositions from bio-sourced and/or recycled resources. Detailed description of the invention The invention relates to at least one method for producing hydrocarbon resins from a feedstock of styrenic compounds, said method comprising at least ■ a. A step of preparing the feedstock of styrenic compounds so as to be able to feed this feedstock into the pyrolysis step; b. A step of pyrolyzing the feedstock of styrenic compounds making it possible to obtain at least one gaseous effluent and one pyrolysis oil, said gaseous effluent comprising at least 20% by weight of aromatic compounds; c. A step of separating the gaseous effluent into at least one stream rich in light compounds, one stream rich in aromatic compounds and one stream rich in heavy compounds; d. A step of synthesizing resins comprising a polymerization section fed at least by a stream from step c) and by a stream of aliphatic compounds comprising at least 5% by weight of terpenic compounds of biosourced origin, followed by a finishing section and producing a polymerized effluent; e. A treatment step comprising a section for separating the polymerized effluent from step c) into a solvent-rich effluent and a resin-rich effluent, and a drying section fed with the resin-rich effluent in order to produce a stream of hydrocarbon resins. Preferably, the charge of styrenic compounds is a charge of styrenic compounds from plastic waste comprising at least 90% by weight of polystyrene. Preferably, the terpene compounds are chosen from terpenes comprising at most 20 carbon atoms, preferably chosen from the compounds limonene, alpha-pinene, beta-pinene, myrcene, farnesene and their mixtures, preferably chosen from the compounds limonene, alpha-pinene, beta-pinene and their mixtures and preferably are limonene. Preferably, the charge of styrenic compounds is gradually heated during step a) to a temperature between 100°C and 300°C, preferably between 150°C and 300°C and