Method for recycling an led

Patent metadata

Field	Value
Publication number	US-2024343969-A1
Application number	US-202218293552-A
Country	US
Kind code	A1
Filing date	Jul 29, 2022
Priority date	Jul 30, 2021
Publication date	Oct 17, 2024
Grant date	—

Abstract

A method for extracting and separating at least one component from a LED, the LED including at least one metal, at least one phosphor and at least one layer including polydimethylsiloxane. Also, an LED having at least one layer including polydimethylsiloxane, wherein the at least one layer comprising polydimethylsiloxane is depolymerized by the action of a solution including a solvent and a fluorine salt.

First claim

1 - 10 . (canceled)

11 . A method for extracting and separating at least one component of an LED, the LED comprising at least one metal, at least one phosphor and at least one layer comprising polydimethylsiloxane, said method comprising the following steps:
a) at least partial depolymerization of at least one layer comprising polydimethylsiloxane using a solution comprising a solvent and a fluoride salt; b) separation of the at least one phosphor and the rest of the LED obtained in step a); c) contacting at least one acidic solution with the rest of the LED obtained in step b); and d) separation of the at least one acidic solution comprising at least part of the at least one metal and the rest of the LED obtained in step c).

12 . The method according to claim 11 , wherein the solvent of the solution used in step a) is selected from the group consisting of tetrahydrofuran, methyltetrahydrofuran, dichloromethane, trichloromethane, acetonitrile, dimethylformamide, N-methyl-2-pyrrolidone, binary solvents, and mixtures thereof, the binary solvents being selected from the group consisting of methyltetrahydrofuran and acetone, methyltetrahydrofuran and acetonitrile, methyltetrahydrofuran and dimethylformamide, and methyltetrahydrofuran and trichloromethane.

13 . The method according to claim 11 , wherein the fluoride salt of the solution used in step a) is a quaternary ammonium fluoride selected from the group consisting of tetrabutylammonium fluoride (TBAF), tetramethylammonium fluoride (TMAF), tetraethylammonium fluoride (TEAF) and tetra-n-octylammonium fluoride (TOAF).

14 . The method according to claim 11 , wherein the at least one acidic solution used in step c) is selected from the group consisting of nitric acid, aqua regia, an acidic thiourea solution, sulfuric acid, a mixture of NaClO—HCl—H 2 O 2 , a mixture of (acetic acid-HCl—CaCl 2 —H 2 O 2 ), a mixture HCl—H 2 O 2 and mixtures thereof.

15 . The method according to claim 11 , further comprising recovering at least a part of the at least one metal by a step e) of separating the at least one acidic solution from at least a part of the at least one metal, for example by precipitation and/or filtration.

16 . The method according to claim 11 , wherein the sequence of process steps c) and d) is repeated with at least one solution different from that used in the first sequence of steps c) and d).

17 . The method according to claim 11 , wherein the at least one metal of the LED is selected from the group consisting of gold, silver, copper, aluminum, tin, iron and combinations thereof.

18 . The method according to claim 11 , wherein the at least one LED is coated by a polyester layer or is present in a polyester layer, and wherein said method comprises, prior to step a), a step 0) of degrading at least a part of the polyester layer using a solution comprising a solvent and a fluorine salt.

19 . The method according to claim 18 , wherein steps 0) and a) are successive or concomitant.

20 . An LED comprising at least one layer comprising polydimethylsiloxane, wherein the at least one layer comprising polydimethylsiloxane is depolymerized by the action of a solution comprising a solvent and a fluorine salt.

Assignees

• Paris Sciences Et Lettres
• Centre Nat Rech Scient
• Ecole Nat Superieure De Chimie De Paris

Inventors

• Wehbie Moheddine
• Semetey Vincent
• Minier Michel

Classifications

• H10H20/0362

  of encapsulations · CPC title

• H10H20/01

  Manufacture or treatment · CPC title

• H10H20/0361

  of wavelength conversion means · CPC title

• H10H20/034

  of coatings · CPC title

• Y02P10/20

  Recycling · CPC title