Removal of color from polymeric materials

Patent metadata

Field	Value
Publication number	US-2023303799-A1
Application number	US-202118020286-A
Country	US
Kind code	A1
Filing date	Aug 17, 2021
Priority date	Aug 17, 2020
Publication date	Sep 28, 2023
Grant date	—

Abstract

The present disclosure is directed to methods for at least partially removing a dye from a dyed fiber comprising one or more polyamide or polyester polymers, and products formed thereof.

First claim

What is claimed is:

1 . A method for at least partially removing one or more colorants from a colored polymeric material, wherein the colored polymeric material comprises a polymer selected from one or more polyester polymers, one or more polyamide polymers, or mixtures thereof, the method comprising:
at least partially dissolving the colored polymeric material in a phenolic solvent to provide a mixture comprising a solubilized portion and an insolubilized portion, wherein the solubilized portion comprises at least a portion of the one or more colorants and the polymer; subjecting the solubilized portion to a separation technique to remove a majority of the one or more colorants from the solubilized portion to provide a solution comprising the polymer; and precipitating the polymer from the solution.

2 - 13 . (canceled)

14 . The method of claim 1 , wherein the phenolic solvent comprises an acidic solvent having a pKa ranging from 7 to 12 as measured in water at 25° C.

15 . (canceled)

16 . The method of claim 1 , wherein the phenolic solvent comprises phenol, m-cresol, o-phenylphenol, p-phenylphenol, o-chlorophenol, or trichlorophenol.

17 - 20 . (canceled)

21 . The method of claim 1 , wherein separating the solubilized portion from the insolubilized portion comprises filtering the insolubilized portion away from the solubilized portion.

22 - 26 . (canceled)

27 . The method of claim 1 , wherein precipitating the polymer from the solution comprises the addition of an alcohol to the solution.

28 . The method of claim 27 , wherein the alcohol is selected from the group consisting of tert-amyl alcohol, benzyl alcohol, 1,4-butanediol, 1,2,4-butanetriol, butanol, 2-butanol, N-butanol, tert-butyl alcohol, di(propylene glycol) methyl ether, diethylene glycol, ethanol, ethylene glycol, 2-ethylhexanol, furfuryl alcohol, glycerol, isobutanol, isopropyl alcohol, methanol, 2-(2-methoxyethoxy)ethanol, 2-methyl-1-butanol, 2-methyl-1-pentanol, 3-methyl-2-butanol, neopentyl alcohol, 2-pentanol, 1,3-propanediol, 1-propanol, propylene glycol, propylene glycol methyl ether, or combinations thereof.

29 . The method of claim 27 , wherein the alcohol comprises isopropanol.

30 . The method of claim 27 , wherein the polymer is isolated by filtration following precipitation from the solution.

31 - 41 . (canceled)

42 . The method of claim 1 , wherein the one or more polyester polymers comprises polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), or combinations thereof.

43 . (canceled)

44 . The method of claim 1 , wherein one or more polyamide polymers comprise polyamide 66, polyamide 6, polyamide 510, polyamide 16, or combinations thereof.

45 - 60 . (canceled)

Assignees

• Aladdin Mfg Corp

Inventors

• Cascio Anthony

Classifications

• C08J11/08

  using selective solvents for polymer components · CPC title

• C08J2377/06

  Polyamides derived from polyamines and polycarboxylic acids (C08J2377/10 takes precedence) · CPC title

• C08J2367/00

  Characterised by the use of polyesters obtained by reactions forming a carboxylic ester link in the main chain; Derivatives of such polymers · CPC title

• C08L77/02

  Polyamides derived from omega-amino carboxylic acids or from lactams thereof (C08L77/10 takes precedence) · CPC title

• C08J11/24 Primary

  containing hydroxyl groups · CPC title