14-01-2016 дата публикации
Номер: US20160009893A1
Принадлежит:
Organic colorants incorporated in colored PET-flake, as being obtained by shredding PET bottles, can be extracted from the PET-flake by extracting the PET-flake with ethylene glycol (EG) at ambient pressure and at the boiling temperature of EG. Pre-treating of PET-flake in EG or other suitable organic compounds prior to extraction enhances the discoloration. 1. Method for pre-processing PET-flake prior to depolymerization by glycolysis , methanolysis , hydrolysis , saponification , and/or any combination of these PET depolymerization processes , the method comprising: contacting the PET-flake with ethylene glycol (EG, IUPAC name: ethane-1,2-diol, CAS: 107-21-1) in a contacting vessel, and', 'removing used ethylene glycol from the contacting vessel and adding fresh ethylene glycol to the contacting vessel,, 'extracting organic colorants from the PET-flake and simultaneous embrittlement of the PET-flake by{'sub': 13', '10', '2', '4', 'n', '6', '4', '2', '10', '16', '4', '8', '2', '2', '6', '2', '6', '14', '4', '8', '18', '5, 'wherein the PET-flake are pre-treated prior to the extraction step by immersing the PET-flake in an organic solvent comprising at least one compound selected from the group consisting of: benzophenone (CHO, CAS: 119-61-9), polyethylene glycol 600 (“PEG”, HO(CHO), CAS: 25322-68-3), 1,2-dichlorobenzene (CHCl, CAS: 95-50-1), limonene (CH, CAS: 5989-27-5), 1,4-dioxane (CHO, CAS: 123-91-1), ethylene glycol (EG, CHO, CAS: 107-21-1), triethylene glycol (“TEG”, CHO, CAS: 112-27-6), and/or tetraethylene glycol (CHO, CAS: 112-60-7).'}2. Method of claim 1 , wherein the PET-flake is contact with the ethylene glycol at ambient pressure.3. Method of claim 1 , wherein said extracting of organic colorants is stopped if the PET-flake show at least one property selected from the group consisting of:an intrinsic viscosity IV<0.20 dL/g;a molar mass Mn with 3000 g/mol≦Mn≦8000 g/mol; anda degree of polymerization Pn<20.4. Method of claim 1 , further comprising ...
Подробнее