Abstract

The present invention relates to the field of the recycling of materials comprising terephthalate polyester, notably polyethylene terephthalate (PET) or polybutylene terephthalate (PBT) or polytrimethylene terephthalate (PTT), which are commonly used for the manufacture of disposable plastic bottles, food trays, textiles, composite material for insulation, etc. The invention notably relates to a method for recycling PET to a terephthalic diester and notably to dimethyl terephthalate (DMT) in less than one hour and without a pretreatment step. In addition, this method uses products with low environmental impact. It is therefore particularly advantageous from an industrial viewpoint.

IPC Classes  ?

• C08J 11/24 - Recovery or working-up of waste materials of polymers by chemically breaking down the molecular chains of polymers or breaking of crosslinks, e.g. devulcanisation by treatment with organic material by treatment with organic oxygen-containing compounds containing hydroxyl groups
• C07C 67/03 - Preparation of carboxylic acid esters by reacting an ester group with a hydroxy group
• C07C 69/82 - Terephthalic acid esters

Abstract

A method for recycling a material comprising terephthalate polyester into terephthalate diester includes milling or shredding the material to produce fragments, and depolymerizing the polyester into terephthalate ester in the presence of: (i) a catalyst selected from a metal or organic ether oxide base, a metal acetate, a metal oxide, a metal hydroxide, a metal ester or a metal carbonate, (ii) a polar solvent of the cyclic ester or ether oxide type, and (iii) an alcohol selected from a monoalcohol or a diol. The base is present in catalytic amount relative to the amount of the polyester, and the depolymerization step is carried out at ambient temperature or by heating up to 70° C. for a period of between 1 minute and 4 hours.

IPC Classes  ?

• C07C 69/82 - Terephthalic acid esters

Abstract

The present invention relates to the field of recycling PET-type plastics commonly used for the manufacture of disposable plastic bottles, food trays, textiles, etc. More specifically, it relates to a method for converting PET into dimethyl terephthalate (DMT) in a few hours (less than 5 hours) by means of a complete reaction resulting in a product free of impurities. The depolymerisation step is carried out in the presence of a monoalcohol as well as an organic base with a guanidine or amidine unit, and a second base which may be either an inorganic base or an ether oxide. These two bases are present in catalytic amounts relative to the amount of PET to be treated.

IPC Classes  ?

• C08J 11/22 - Recovery or working-up of waste materials of polymers by chemically breaking down the molecular chains of polymers or breaking of crosslinks, e.g. devulcanisation by treatment with organic material by treatment with organic oxygen-containing compounds
• C08J 11/28 - Recovery or working-up of waste materials of polymers by chemically breaking down the molecular chains of polymers or breaking of crosslinks, e.g. devulcanisation by treatment with organic material by treatment with organic compounds containing nitrogen, sulfur or phosphorus

Abstract

The present invention relates to the field of recycling materials comprising terephthalate polyester, notably polyethylene terephthalate (PET) or polybutylene terephthalate (PBT) which are commonly used for the manufacture of single-use plastic bottles, food trays, textiles, composite material for insulation, etc. The invention also relates to a method for recycling PET to terephthalic diester and in particular to dimethyl terephthalate (DMT) in less than one hour and without a pretreatment step. Furthermore, this method does not use toxic products. It is therefore particularly advantageous from an industrial viewpoint.

IPC Classes  ?

• C08J 11/22 - Recovery or working-up of waste materials of polymers by chemically breaking down the molecular chains of polymers or breaking of crosslinks, e.g. devulcanisation by treatment with organic material by treatment with organic oxygen-containing compounds
• C08J 11/24 - Recovery or working-up of waste materials of polymers by chemically breaking down the molecular chains of polymers or breaking of crosslinks, e.g. devulcanisation by treatment with organic material by treatment with organic oxygen-containing compounds containing hydroxyl groups
• C08J 11/26 - Recovery or working-up of waste materials of polymers by chemically breaking down the molecular chains of polymers or breaking of crosslinks, e.g. devulcanisation by treatment with organic material by treatment with organic oxygen-containing compounds containing carboxylic acid groups, their anhydrides or esters

Abstract

The present invention relates to the field of recycling materials comprising terephthalate polyester, notably polyethylene terephthalate (PET) or polybutylene terephthalate (PBT) which are commonly used for the manufacture of single-use plastic bottles, food trays, textiles, composite material for insulation, etc. The invention also relates to a method for recycling PET to terephthalic diester and in particular to dimethyl terephthalate (DMT) in less than one hour and without a pretreatment step. Furthermore, this method does not use toxic products. It is therefore particularly advantageous from an industrial viewpoint.

IPC Classes  ?

• C08J 11/22 - Recovery or working-up of waste materials of polymers by chemically breaking down the molecular chains of polymers or breaking of crosslinks, e.g. devulcanisation by treatment with organic material by treatment with organic oxygen-containing compounds
• C08J 11/24 - Recovery or working-up of waste materials of polymers by chemically breaking down the molecular chains of polymers or breaking of crosslinks, e.g. devulcanisation by treatment with organic material by treatment with organic oxygen-containing compounds containing hydroxyl groups
• C08J 11/26 - Recovery or working-up of waste materials of polymers by chemically breaking down the molecular chains of polymers or breaking of crosslinks, e.g. devulcanisation by treatment with organic material by treatment with organic oxygen-containing compounds containing carboxylic acid groups, their anhydrides or esters

Abstract

The present invention relates to the field of recycling PET-type plastics commonly used for the manufacture of disposable plastic bottles, food trays, textiles, etc. More specifically, it relates to a method for converting PET into dimethyl terephthalate (DMT) in a few hours (less than 5 hours) by means of a complete reaction resulting in a product free of impurities. The depolymerisation step is carried out in the presence of a monoalcohol as well as an organic base with a guanidine or amidine unit, and a second base which may be either an inorganic base or an ether oxide. These two bases are present in catalytic amounts relative to the amount of PET to be treated.

IPC Classes  ?

• C07C 67/03 - Preparation of carboxylic acid esters by reacting an ester group with a hydroxy group
• C07C 69/82 - Terephthalic acid esters
• C08J 11/14 - Recovery or working-up of waste materials of polymers by chemically breaking down the molecular chains of polymers or breaking of crosslinks, e.g. devulcanisation by treatment with steam or water
• C08J 11/22 - Recovery or working-up of waste materials of polymers by chemically breaking down the molecular chains of polymers or breaking of crosslinks, e.g. devulcanisation by treatment with organic material by treatment with organic oxygen-containing compounds
• C08J 11/28 - Recovery or working-up of waste materials of polymers by chemically breaking down the molecular chains of polymers or breaking of crosslinks, e.g. devulcanisation by treatment with organic material by treatment with organic compounds containing nitrogen, sulfur or phosphorus

Abstract

The present invention relates to the field of recycling PET-type plastics commonly used for the manufacture of disposable plastic bottles, food trays, textiles, etc. More specifically, it relates to a method for converting PET into dimethyl terephthalate (DMT) in a few hours (less than 5 hours) by means of a complete reaction resulting in a product free of impurities. The depolymerisation step is carried out in the presence of a monoalcohol as well as an organic base with a guanidine or amidine unit, and a second base which may be either an inorganic base or an ether oxide. These two bases are present in catalytic amounts relative to the amount of PET to be treated.

IPC Classes  ?

• C07C 67/03 - Preparation of carboxylic acid esters by reacting an ester group with a hydroxy group
• C07C 69/82 - Terephthalic acid esters
• C08J 11/28 - Recovery or working-up of waste materials of polymers by chemically breaking down the molecular chains of polymers or breaking of crosslinks, e.g. devulcanisation by treatment with organic material by treatment with organic compounds containing nitrogen, sulfur or phosphorus
• C08J 11/14 - Recovery or working-up of waste materials of polymers by chemically breaking down the molecular chains of polymers or breaking of crosslinks, e.g. devulcanisation by treatment with steam or water
• C08J 11/22 - Recovery or working-up of waste materials of polymers by chemically breaking down the molecular chains of polymers or breaking of crosslinks, e.g. devulcanisation by treatment with organic material by treatment with organic oxygen-containing compounds