RECYCLING PROCESS

Abstract

The invention relates to a process for extracting polyester from packaging. In particular, the invention relates to packaging comprising one or more dyes such as black packaging. The claim process uses a two stage extraction process to convert waste polyester in clean, reusable polyester.

The invention relates to a process for extracting polyester from fabric. In particular, fabric comprising polyester and one or more dyes. The claimed process uses a multistage mechanism to separate dyes from polyester containing garments and reconstitute the polyester.

Claims

1. A process for extracting polyester from packaging containing one or more dyes comprising the steps of: a) contacting the packaging with a first solvent system to form a mixture; b) maintaining the mixture at a first temperature for a first period of time until substantially all of the dye has been dissolved; c) removing the first solvent system containing the dissolved dye; d) contacting the remaining mixture with a second solvent system in order to dissolve the polyester; e) maintaining the remaining mixture at the second temperature for a second period of time until substantially all of the polyester has been dissolved; f) removing the second solvent system containing the dissolved polyester; and g) recovering the polyester from the second solvent system; wherein the first and second solvent systems are each food grade solvents wherein the second temperature is greater than the first temperature when the first solvent system and the second solvent system are the same.

2. A process according to claim 1, wherein the first solvent system is selected from: cycloalkenes; ketones; esters; carbonates; or combinations thereof or combinations thereof.

3. A process according to claim 2, wherein the cycloalkenes comprise limonene.

4. A process according to claim 2, wherein the ketones comprise cyclopentanone; acetone; or combinations thereof.

5. A process according to claim 2, wherein the esters are alkyl esters.

6. A process according to claim 5, wherein the alkyl esters are selected from: ethyl acetate; propyl acetate; butyl acetate; isobutyl acetate; tert-butyl acetate; amyl acetate; isoamyl acetate; ethyl propionate; ethyl butyrate; ethyl isobutyrate; propyl propionate; propyl butyrate; butyl butyrate; isobutyl butyrate; butyl isobutyrate; isobutyl isobutyrate; ethyl valerate; propyl valerate; butyl valerate; amyl valerate; or combinations thereof.

7. A process according to claim 6, wherein the first solvent system comprises ethyl acetate.

8. A process according to claim 2, wherein the carbonates are selected from dimethyl carbonate, diethyl carbonate or combinations thereof.

9. A process according to any preceding claim, wherein the second solvent system comprises solvents selected from: arenes; cyclic ether; aldehydes; ketones; esters; or combinations thereof.

10. A process according to claim 9, wherein the arenes are substituted benzenes.

11. A process according to claim 10, wherein the substituted benzenes are alkyl and/or alkoxy benzenes.

12. A process according to claim 11, wherein the alkyl benzene is p-cymene.

13. A process according to claim 11, wherein the alkoxy benzenes are selected from: dimethoxybenzene, anethole, vanillyl butyl ether, methoxyohenyl butanone, or combinations thereof.

14. A process according to claim 9, wherein the cyclic ether is cineole.

15. A process according to claim 9, wherein the aldehydes comprise a solvent selected from: benzaldehyde; anisaldehyde; phenylacetaldehyde; cinnamaldehyde; phenyl butenal; or combinations thereof.

16. A process according to claim 9, wherein the ketones are selected from: menthone; fenchone; carvone; acetophenone; methoxyacetophenone; propiophenone; butyrophenone; or combinations thereof.

17. A process according to claim 9, wherein the esters are selected from: acetyl tributyl citrate; menthyl acetate; fenchyl acetate; bornyl acetate; gamma-butyrolactone; gamma-valerolactone; gamma-caprolactone; alpha-angelicalactone; methyl benzoate; ethyl benzoate; propyl benzoate; isopropyl benzoate; butyl benzoate; isobutyl benzoate; sec-butyl benzoate; tert-butyl benzoate; amyl benzoate; isoamyl benzoate; hexyl benzoate; benzyl acetate; benzyl propionate; benzyl butyrate; benzyl isobutyrate; benzyl 2-methylbutyrate; benzyl valerate; benzyl benzoate methyl phenylacetate; methyl cinnamate; ethyl cinnamate; propyl cinnamate; cinnamyl acetate; cinnamyl propionate; phenyl benzoate; anisyl acetate; 2-phenethyl 2-methylbutyrate; methyl salicylate; ethyl salicylate; methyl anisate; ethyl anisate; or combinations thereof.

18. A process according to claim 17, wherein the esters are selected from: methyl benzoate; ethyl benzoate; propyl benzoate; isopropyl benzoate; butyl benzoate; isobutyl benzoate; sec-butyl benzoate; tert-butyl benzoate; amyl benzoate; isoamyl benzoate; hexyl benzoate; methyl cinnamate; ethyl cinnamate; propyl cinnamate; cinnamyl acetate; cinnamyl propionate; phenyl benzoate; or combinations thereof.

19. A process according to claim 18, wherein the esters are alkyl esters.

20. A process according to claim 19, wherein the alkyl esters comprise methyl and/or ethyl benzoate.

21. A process according to claim 1, wherein the first and second solvent systems are the same and both comprise solvents selected from: arenes; cyclic ethers; aldehydes; ketones; esters; or combinations thereof.

22. A process according to claim 21, wherein the arenes are substituted benzenes.

23. A process according to claim 22, wherein the substituted benzenes are alkyl and/or alkoxy benzenes.

24. A process according to claim 23, wherein the alkyl benzene is p-cymene.

25. A process according to claim 23, wherein the alkoxy benzenes are selected from: dimethoxybenzene, anethole, vanillyl butyl ether, methoxyohenyl butanone, or combinations thereof.

26. A process according to claim 21, wherein the cyclic ether is cineole.

27. A process according to claim 21, wherein the aldehydes comprise a solvent selected from: benzaldehyde; anisaldehyde; phenylacetaldehyde; cinnamaldehyde; phenyl butenal; or combinations thereof.

28. A process according to claim 21, wherein the ketones are selected from: menthone; fenchone; carvone; acetophenone; methoxyacetophenone; propiophenone; butyrophenone; or combinations thereof.

29. A process according to claim 21, wherein the esters are selected from: acetyl tributyl citrate; menthyl acetate; fenchyl acetate; bornyl acetate; gamma-butyrolactone; gamma-valerolactone; gamma-caprolactone; alpha-angelicalactone; alkyl benzoate; methyl benzoate; ethyl benzoate; propyl benzoate; isopropyl benzoate; butyl benzoate; isobutyl benzoate; sec-butyl benzoate; tert-butyl benzoate; amyl benzoate; isoamyl benzoate; hexyl benzoate; benzyl acetate; benzyl propionate; benzyl butyrate; benzyl isobutyrate; benzyl 2-methylbutyrate; benzyl valerate; benzyl benzoate methyl phenylacetate; methyl cinnamate; ethyl cinnamate; propyl cinnamate; cinnamyl acetate; cinnamyl propionate; phenyl benzoate; anisyl acetate; 2-phenethyl 2-methylbutyrate; methyl salicylate; ethyl salicylate; methyl anisate; ethyl anisate; or combinations thereof.

30. A process according to claim 29, wherein the esters are selected from: methyl benzoate; ethyl benzoate; propyl benzoate; isopropyl benzoate; butyl benzoate; isobutyl benzoate; sec-butyl benzoate; tert-butyl benzoate; amyl benzoate; isoamyl benzoate; hexyl benzoate; methyl cinnamate; ethyl cinnamate; propyl cinnamate; cinnamyl acetate; cinnamyl propionate; phenyl benzoate; or combinations thereof.

31. A process according to claim 30, wherein the esters are alkyl esters.

32. A process according to claim 31, wherein the esters comprise methyl and/or ethyl benzoate.

33. A process according to any preceding claim, wherein the polyester is selected from: Polyglycolic acid (PGA), Polylactic acid (PLA), Polycaprolactone (PCL), Polyethylene adipate (PEA), Polyhydroxyalkanoate (PHA), Polyethylene terephthalate (PET), Polybutylene terephthalate (PBT), Polytrimethylene terephthalate (PTT), Polyethylene naphthalate (PEN) or combination thereof.

34. A process according to claim 34, wherein the polyester is polyethylene terephthalate.

35. A process according to any preceding claim, wherein the packaging comprises food packaging.

36. A process according to any preceding claim, wherein the packaging comprises black packaging.

37. A process according to any preceding claim, wherein the packaging comprises bottles.

38. A process according to claim any preceding claim, wherein the first temperature is in the range 70° C.-120° C.

39. A process according to claim 38, wherein the first temperature is in the range 90° C.-100° C.

40. A process according to any preceding claim, wherein the second temperature is in the range 70° C.-200° C.

41. A process according to claim 40, wherein the second temperature is in the range 80° C.-150° C.

42. A process according to claim 41, wherein the second temperature is in the range 90° C.-100° C.

43. A process according to any preceding claim, wherein the second temperature is greater than the first temperature.

44. A process according to any preceding claim, further comprising the step of recovering the dye from the first solvent system.

45. A process according to claim 44, wherein at least some of the first solvent system is reused as the first solvent system in step a) and/or wherein the first solvent system is reused as the second solvent system in step d).

46. A process according to claim 45, wherein the first solvent system is reused as the first solvent system in step a).

47. A process according to any preceding claim, wherein the second solvent system is reused as the first solvent system in step a) and/or wherein the second solvent system is reused as the second solvent system in step d).

48. A process according to claim 47, wherein the second solvent system is reused as the first solvent system in step d).

49. A process according to any preceding claim, wherein the first and/or the second solvent system are homogeneous.

50. A process according to any preceding claim, wherein the first period of time is in the range 5 minutes to 120 minutes.

51. A process according to claim 49, wherein the first period of time is in the range 5 minutes to 20 minutes.

52. A process according to any preceding claim, further comprising a filtration step to remove undissolved impurities from the second solvent system comprising the dissolved polyester.

53. A process according to any preceding claim, wherein the packaging is black packaging.

54. A process for extracting polyester from fabric containing one or more dyes comprising the steps of: a) contacting the fabric with a first solvent system to form a mixture; b) maintaining the mixture at a first temperature for a first period of time until substantially all of the dye has been dissolved; c) removing the first solvent system containing the dissolved dye; d) contacting the remaining mixture with a second solvent system in order to dissolve the polyester; e) maintaining the remaining mixture at the second temperature for a second period of time until substantially all of the polyester has been dissolved; f) removing the second solvent system containing the dissolved polyester; and g) recovering the polyester from the second solvent system; wherein the second temperature is greater than the first temperature when the first solvent system and second solvent system are the same; and wherein the first and/or second solvent systems are selected from: amides; esters; arenes; heteroarenes; haloalkanes; haloalkenes; cycloalkanes; cyclic ethers; aldehydes; ketones; carbonates; sulfoxides; nitriles; ionic liquids; phosphorus containing compounds; or combinations thereof.

55. A process according to claim 55, wherein the first solvent system and the second solvent system are different.

56. A process according to claim 56, wherein the first solvent system comprises one or more solvents selected from: ketones, haloalkanes, haloalkenes, arenes, substituted cycloalkanes, esters, carbonates or combinations thereof.

57. A process according to claim 57, wherein the first solvent system comprises ketones.

58. A process according to claim 58, wherein the ketones are cyclic ketones.

59. A process according to claim 59, wherein the cyclic ketones comprise: pivalone; cyclopentyl methyl ketone; cyclohexanone; cycloheptanone; cyclopentanone; or combinations thereof.

60. A process according to claim 60, wherein the cyclic ketone comprises cyclohexanone.

61. A process according to claim 58, wherein the haloalkanes and haloalkenes are selected from chloro and/or bromo alkanes and alkenes.

62. A process according to claim 62, wherein the haloalkanes and haloalkenes are selected from: dichloromethane; chloroform; dichloroethane; trichloroethane; tetrachloroethane; dichloroethene; dibromomethane; bromopropane; dibromopropane; or combinations thereof.

63. A process according to claim 58, wherein the arenes are selected from: alkyl arenes; nitroarenes; amino-substituted arenes; substituted heterocyclic arenes; or combinations thereof.

64. A process according to claim 64, wherein the alkyl arenes are selected from: benzene; toluene; xylene; ethylbenzene.

65. A process according to claim 64, wherein the amino-substituted arenes include: aniline; N,N-dimethylaniline; N,N-diethylaniline; pyridine; or combinations thereof.

66. A process according to claim 58, wherein the substituted cycloalkanes are substituted heterocycloalkanes.

67. A process according to claim 67, wherein the substituted heterocycloalkanes are selected from: tetrahydrofuran; tetrahydrosilvan; tetrahydropyran; dimethoxyethane; dioxolane; anisole; morpholine; or combinations thereof.

68. A process according to claim 58, wherein the esters are alkyl esters.

69. A process according to claim 69, wherein the alkyl esters are selected from: ethyl acetate; propyl acetate; butyl acetate; isobutyl acetate; tert-butyl acetate; amyl acetate; isoamyl acetate; ethyl propionate; ethyl butyrate; ethyl isobutyrate; propyl propionate; propyl butyrate; butyl butyrate; isobutyl butyrate; butyl isobutyrate; isobutyl isobutyrate; ethyl valerate; propyl valerate; butyl valerate; amyl valerate; or combinations thereof.

70. A process according to claim 58, wherein the carbonates are selected from: dimethyl carbonate; diethyl carbonate; or combinations thereof.

71. A process according to any of claims 58 to 71, wherein the second solvent system comprises: amides; heteroarenes; cyclic ethers; aldehydes; ketones; esters; arenes; sulfoxides; nitriles; ionic liquids; phosphorus containing compounds; or combinations thereof.

72. A process according to claim 72, wherein the second solvent system comprises amides.

73. A process according to claim 73, wherein amides are selected from: dimethylformamide; diethylformamide; ethylmethylformamide; dipropylformamide; dibutylformamide; dimethylacetamide; diethylacetamide; dimethylpropionamide; dimethylbutyramide; or combinations thereof.

74. A process according to claim 73, wherein the amides are cyclic amides.

75. A process according to claim 75, wherein cyclic amides are selected from compounds according to any of general Formula I ##STR00004## wherein R.sup.1 and R.sup.2 are each independently selected from: hydrogen, alkyl, alkenyl, alkynyl, aryl or alkoxy groups; R.sup.3 to R.sup.12 are each independently selected from: hydrogen, alkyl, alkenyl, alkynyl, aryl or alkoxy groups; wherein each of a to e is a carbon atom, wherein the total linear chain length of a-b-c-d-e is in the range 2 to 5 carbons.

76. A process according to claim 75, wherein the cyclic amides include: N-methyl-2-pyrrolidinone; N-ethyl-2-pyrrolidinone; N-acetyl-2-pyrrolidinone; delta-valerolactam; epsilon-caprolactam; N-methyl-epsilon-caprolactam; N-acetyl-epsilon-caprolactam; N-phenyl-2-pyrrolidinone; N-benzyl-2-pyrrolidinone; 1,3-dimethyltetrahydro-2-pyrimidone; 1,3-diethyltetrahydro-2-pyrimidone; 1,3-dimethyl-2-imidazolidinone; 1,3-diethyl-2-imidazolidinone; or combinations thereof.

77. A process according to claim 77, wherein the second solvent system comprises 1,3-dimethyl-2-imidazolidinone.

78. A process according to claim 72, wherein the arenes are selected from: alkyl arenes; alkoxy arenes; haloalkyl arenes; or combinations thereof.

79. A process according to claim 79, wherein the alkyl arenes are selected from: p-cymene; diethylbenzene; trimethylbenzene; mesitylene; durene; cumene; propylbenzene; butylbenzene; isobutylbenzene; tert-butylbenzene; butyltoluene; amylbenzene; hexylbenzene; tetrahydronaphthalene; 1-methylnaphthalene; diphenylmethane; or combinations thereof.

80. A process according to claim 79, wherein the alkoxy arenes are selected from: dimethoxybenzene; veratrole; anethole; phenetole; vanillyl butyl ether; 4-(p-methoxyphenyl)-2-butanone; hydroquinone diethyl ether; propyl phenyl ether; butyl phenyl ether; benzyl methyl ether; benzyl ethyl ether; benzyl propyl ether; benzyl butyl ether; diphenyl ether; dibenzyl ether; eugenol methyl ether; isoeugenol methyl ether; methylchavicol; or combinations thereof.

81. A process according to claim 79, wherein the haloalkyl arenes are selected from: chloroanisole; bromoanisole; diphenylchloromethane; 1-chloro-2-phenylethane; benzyl bromide; chlorobenzene; dichlorobenzene; chlorotoluene; bromobenzene; iodobenzene; benzyl chloride; or combinations thereof.

82. A process according to claim 72, wherein the heteroarenes comprise one or more substitutions of a carbon atom with a nitrogen or an oxygen atom.

83. A process according to claim 83, wherein one carbon atom has been substituted.

84. A process according to claim 83 or 84, wherein the carbon is substituted with a nitrogen atom.

85. A process according to claim 85, wherein the heteroarenes are selected from: N-acetylmorpholine; N-propionylmorpholine; N-methylformanilide; N-ethylformanilide; N-acetylhomopiperazine; acetylpyridine; N,N′-diacetylpiperazine; or combinations thereof.

86. A process according to claim 72, wherein the cyclic ethers are selected from: cineole; alpha-pinene oxide; or combinations thereof.

87. A process according to claim 72, wherein the aldehydes are selected from: benzaldehyde; anisaldehyde; 2-phenylacetaldehyde; cinnamaldehyde; 2-phenyl-2-butenal; or combinations thereof.

88. A process according to claim 72, wherein the esters are selected from: acetyl tributyl citrate; menthyl acetate; fenchyl acetate; bornyl acetate; gamma-butyrolactone; gamma-valerolactone; gamma-caprolactone; alpha-angelicalactone; alkyl benzoate; methyl benzoate; ethyl benzoate; propyl benzoate; isopropyl benzoate; butyl benzoate; isobutyl benzoate; sec-butyl benzoate; tert-butyl benzoate; amyl benzoate; isoamyl benzoate; hexyl benzoate; benzyl acetate; benzyl propionate; benzyl butyrate; benzyl isobutyrate; benzyl 2-methylbutyrate; benzyl valerate; benzyl benzoate; methyl phenylacetate; methyl cinnamate; ethyl cinnamate; propyl cinnamate; cinnamyl acetate; cinnamyl propionate; phenyl benzoate; anisyl acetate; 2-phenethyl 2-methylbutyrate; methyl salicylate; ethyl salicylate; methyl o-anisate; methyl m-anisate; methyl p-anisate; ethyl anisate; ethylene glycol phenyl ether acetate; ethylene glycol 2-phenethyl ether acetate; propylene glycol phenyl ether acetate; propylene glycol benzyl ether acetate; diethylene glycol methyl ether benzoate; diethylene glycol benzyl ether acetate; dipropylene glycol methyl ether acetate; dipropylene glycol ethyl ether acetate; dipropylene glycol propyl ether acetate; dipropylene glycol butyl ether acetate; dipropylene glycol phenyl ether acetate; dipropylene glycol benzyl ether acetate; cyclohexyl benzoate; dimethyl phthalate; diethyl phthalate; dipropyl phthalate; dibutyl phthalate; diamyl phthalate; methyl ethyl phthalate; methyl ethyl phthalate; methyl propyl phthalate; methyl butyl phthalate; dimethyl isophthalate; diethyl isophthalate; dimethyl terephthalate; diethyl terephthalate; dipropyl terephthalate; dibutyl terephthalate; diisopropyl terephthalate; diisobutyl terephthalate; diethylene glycol dibenzoate; dipropylene glycol dibenzoate; trimethyl orthobenzoate; triethyl orthobenzoate; or combinations thereof.

89. A process according to claim 72, wherein the esters comprise compounds according to general formulae IV and V wherein R.sup.14 is an aryl group and wherein R.sup.17 to R.sup.19 are each independently selected from hydrogen, alkyl, alkenyl, alkynyl or aryl groups; n is an integer in the range 1 to 8 and m is 3.

90. A process according to claim 72, wherein the sulfoxides are selected from: dimethylsulfoxide; methyl ethyl sulfoxide; diethylsulfoxide; dipropylsulfoxide; dibutylsulfoxide; diisopropylsulfoxide; diisobutylsulfoxide; tetramethylenesulfoxide; or combinations thereof.

91. A process according to claim 72, the nitrile compounds are selected from: benzonitrile; phenylacetonitrile; cinnamonitrile; or combinations thereof.

92. A process according to claim 72, wherein the phosphorus containing compounds are selected from: triethyl phosphite; triethyl phosphate; tripropyl phosphate; tributyl phosphate; dimethylphosphate; hexamethylphosphoramide; or combinations thereof.

93. A process according to claim 57, wherein the second solvent system comprises an ionic liquid.

94. A process according to claim 94, wherein comprises a compound according to general formula VI ##STR00005## wherein R.sup.15 is an aryl groups and R.sup.16 is selected from hydrogen, alkyl, alkenyl, alkynyl or aryl groups; and 1 is an integer in the range 1 to 3.

95. A process according to claim 94, wherein the ionic liquid comprises an imidazolium cation.

96. A process according to claim 96, wherein the imidazolium cation is selected from: 1,3-dimethylimidazolium; 1-ethyl-3-methylimidazolium; 1-butyl-3-methylimidazolium; or combinations thereof.

97. A process according to claim 97, wherein the counter ions comprise acetate, benzoate or a combination thereof.

98. A process according to claim 94, wherein the ionic liquids comprises tris(2-(2-methoxyethoxy)ethyl)ammonium benzoate.

99. A process according to claim 55, wherein the first and second solvent systems are the same.

100. A process according to claim 100, wherein the first and second solvent systems comprise: amides; heteroarenes; cyclic ethers; aldehydes; ketones; esters; arenes; sulfoxides; nitriles; ionic liquids; phosphorus containing compounds; or combinations thereof.

101. A process according to claim 101, wherein the second solvent system comprises amides.

102. A process according to claim 102, wherein the amides are cyclic amides.

103. A process according to claim 102, wherein amides are selected from: dimethylformamide; diethylformamide; ethylmethylformamide; dipropylformamide; dibutylformamide; dimethylacetamide; diethylacetamide; dimethylpropionamide; dimethylbutyramide; or combinations thereof.

104. A process according to claim 103, wherein cyclic amides are selected from compounds according to any of general Formula I wherein R.sup.1 and R.sup.2 are each independently selected from: hydrogen, alkyl, alkenyl, alkynyl, aryl or alkoxy groups; R.sup.3 to R.sup.12 are each independently selected from: hydrogen, alkyl, alkenyl, alkynyl, aryl or alkoxy groups; wherein each of a to e is a carbon atom, wherein the total linear chain length of a-b-c-d-e is in the range 2 to 5 carbons.

105. A process according to claim 103, wherein the cyclic amides include: N-methyl-2-pyrrolidinone; N-ethyl-2-pyrrolidinone; N-acetyl-2-pyrrolidinone; delta-valerolactam; epsilon-caprolactam; N-methyl-epsilon-caprolactam; N-acetyl-epsilon-caprolactam; N-phenyl-2-pyrrolidinone; N-benzyl-2-pyrrolidinone; 1,3-dimethyltetrahydro-2-pyrimidone; 1,3-diethyltetrahydro-2-pyrimidone; 1,3-dimethyl-2-imidazolidinone; 1,3-diethyl-2-imidazolidinone; or combinations thereof.

106. A process according to claim 106, wherein the second solvent system comprises 1,3-dimethyl-2-imidazolidinone.

107. A process according to claim 47, wherein the arenes are selected from: alkyl arenes; alkoxy arenes; haloalkyl arenes; or combinations thereof.

108. A process according to claim 54, wherein the alkyl arenes are selected from: p-cymene; diethylbenzene; trimethylbenzene; mesitylene; durene; cumene; propylbenzene; butylbenzene; isobutylbenzene; tert-butylbenzene; butyltoluene; amylbenzene; hexylbenzene; tetrahydronaphthalene; 1-methylnaphthalene; diphenylmethane; or combinations thereof.

109. A process according to claim 54, wherein the alkoxy arenes are selected from: dimethoxybenzene; veratrole; anethole; phenetole; vanillyl butyl ether; 4-(p-methoxyphenyl)-2-butanone; hydroquinone diethyl ether; propyl phenyl ether; butyl phenyl ether; benzyl methyl ether; benzyl ethyl ether; benzyl propyl ether; benzyl butyl ether; diphenyl ether; dibenzyl ether; eugenol methyl ether; isoeugenol methyl ether; methylchavicol; or combinations thereof.

110. A process according to claim 54, wherein the haloalkyl arenes are selected from: chloroanisole; bromoanisole; diphenylchloromethane; 1-chloro-2-phenylethane; benzyl bromide; chlorobenzene; dichlorobenzene; chlorotoluene; bromobenzene; iodobenzene; benzyl chloride; or combinations thereof.

111. A process according to claim 101, wherein the heteroarenes comprise one or more substitutions of a carbon atom with a nitrogen or oxygen atom.

112. A process according to claim 112, wherein one carbon atom has been substituted.

113. A process according to claim 112 or 113, wherein the carbon is substituted with a nitrogen atom.

114. A process according to claim 114, wherein the heteroarenes are selected from: N-acetylmorpholine; N-propionylmorpholine; N-methylformanilide; N-ethylformanilide; N-acetylhomopiperazine; acetylpyridine; N,N′-diacetylpiperazine; or combinations thereof.

115. A process according to claim 101, wherein the cyclic ethers are selected from: cineole; alpha-pinene oxide; or combinations thereof.

116. A process according to claim 101, wherein the aldehydes are selected from: benzaldehyde; anisaldehyde; 2-phenylacetaldehyde; cinnamaldehyde; 2-Phenyl-2-butenal; or combinations thereof.

117. A process according to claim 101, wherein the esters are selected from: acetyl tributyl citrate; menthyl acetate; fenchyl acetate; bornyl acetate; gamma-butyrolactone; gamma-valerolactone; gamma-caprolactone; alpha-angelicalactone; alkyl benzoate; methyl benzoate; ethyl benzoate; propyl benzoate; isopropyl benzoate; butyl benzoate; isobutyl benzoate; sec-butyl benzoate; tert-butyl benzoate; amyl benzoate; isoamyl benzoate; hexyl benzoate; benzyl acetate; benzyl propionate; benzyl butyrate; benzyl isobutyrate; benzyl 2-methylbutyrate; benzyl valerate; benzyl benzoate; methyl phenylacetate; methyl cinnamate; ethyl cinnamate; propyl cinnamate; cinnamyl acetate; cinnamyl propionate; phenyl benzoate; anisyl acetate; 2-Phenethyl 2-methylbutyrate; methyl salicylate; ethyl salicylate; methyl o-anisate; methyl m-anisate; methyl p-anisate; ethyl anisate; ethylene glycol phenyl ether acetate; ethylene glycol 2-phenethyl ether acetate; propylene glycol phenyl ether acetate; propylene glycol benzyl ether acetate; diethylene glycol methyl ether benzoate; diethylene glycol benzyl ether acetate; dipropylene glycol methyl ether acetate; dipropylene glycol ethyl ether acetate; dipropylene glycol propyl ether acetate; dipropylene glycol butyl ether acetate; dipropylene glycol phenyl ether acetate; dipropylene glycol benzyl ether acetate; cyclohexyl benzoate; dimethyl phthalate; diethyl phthalate; dipropyl phthalate; dibutyl phthalate; diamyl phthalate; methyl ethyl phthalate; methyl ethyl phthalate; methyl propyl phthalate; methyl butyl phthalate; dimethyl isophthalate; diethyl isophthalate; dimethyl terephthalate; diethyl terephthalate; dipropyl terephthalate; dibutyl terephthalate; diisopropyl terephthalate; diisobutyl terephthalate; diethylene glycol dibenzoate; dipropylene glycol dibenzoate; trimethyl orthobenzoate; triethyl orthobenzoate; or combinations thereof.

118. A process according to claim 101, wherein the esters comprise compounds according to general formulae IV and V wherein R.sup.14 is an aryl group and wherein R.sup.17 to R.sup.19 are each independently selected from hydrogen, alkyl, alkenyl, alkynyl or aryl groups; n is an integer in the range 1 to 8 and m is 3.

119. A process according to claim 101, wherein the sulfoxides are selected from: dimethylsulfoxide; methyl ethyl sulfoxide; diethylsulfoxide; dipropylsulfoxide; dibutylsulfoxide; diisopropylsulfoxide; diisobutylsulfoxide; tetramethylenesulfoxide; or combinations thereof.

120. A process according to claim 101, the nitrile compounds are selected from: benzonitrile; phenylacetonitrile; cinnamonitrile; nitrobenzene; or combinations thereof.

121. A process according to claim 101, wherein the phosphorus containing compound are selected from: triethyl phosphite; triethyl phosphate; tripropyl phosphate; tributyl phosphate; dimethylphosphate; hexamethylphosphoramide; or combinations thereof.

122. A process according to claim 101, wherein the second solvent system comprises an ionic liquid.

123. A process according to claim 123, wherein comprises a compound according to general formula VI ##STR00006## wherein R.sup.15 is an aryl groups and R.sup.16 is selected from hydrogen, alkyl, alkenyl, alkynyl or aryl groups; and 1 is an integer in the range 1 to 3.

124. A process according to claim 123, wherein the ionic liquid comprises an imidazolium cation.

125. A process according to claim 125, wherein the imidazolium cation is selected from: 1,3-dimethylimidazolium; 1-ethyl-3-methylimidazolium; 1-butyl-3-methylimidazolium; or combinations thereof.

126. A process according to claim 125, wherein the counter ions comprises acetate, benzoate or a combination thereof.

127. A process according to claim 123, wherein the ionic liquids comprises tris(2-(2-methoxyethoxy)ethyl)ammonium benzoate.

128. A process according to any of claims 55 to 128, wherein the polyester is selected from: Polyglycolic acid (PGA), Polylactic acid (PLA), Polycaprolactone (PCL), Polyethylene adipate (PEA), Polyhydroxyalkanoate (PHA), Polyethylene terephthalate (PET), Polybutylene terephthalate (PBT), Polytrimethylene terephthalate (PTT), Polyethylene naphthalate (PEN) or combination thereof.

129. A process according to claim 129, wherein the polyester is polyethylene terephthalate.

130. A process according to any of claims 55 to 130, wherein the first temperature is in the range 70° C.-120° C.

131. A process according to claim 131, wherein the first temperature is in the range 90° C.-100° C.

132. A process according to any of claims 55 to 132, wherein the second temperature is in the range 70° C.-200° C.

133. A process according to claim 133, wherein the second temperature is in the range 80° C.-150° C.

134. A process according to claim 134, wherein the second temperature is in the range 90° C.-100° C.

135. A process according to any of claims 55 to 135, wherein the second temperature is greater than the first temperature.

136. A process according to any of claims 55 to 136, further comprising the step of recovering the dye from the first solvent system.

137. A process according to claim 137, wherein the first solvent is reused as the first solvent system in step a) and/or wherein the first solvent system is reused as the second solvent in step d).

138. A process according to claim 138, wherein the first solvent is reused as the first solvent system in step a).

139. A process according to any of claims 55 to 139, wherein the second solvent is reused as the first solvent system in step a) and/or wherein the second solvent system is reused as the second solvent system in step d).

140. A process according to claim 140, wherein the second solvent is reused as the first solvent system in step d).

141. A process according to any of claims 55 to 141, wherein the first and/or the second solvent system are homogeneous.

142. A process according to any of claims 55 to 142, wherein the first period of time is in the range 5 minutes to 120 minutes.

143. A process according to claim 143, wherein the first period of time is in the range 5 minutes to 20 minutes.

144. A process according to any of claims 55 to 144, further comprising a filtration step to remove undissolved impurities from the second solvent system comprising the dissolved polyester.

145. A process as described in the description, examples and drawings disclosed herein.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0104] FIGS. 1 and 2 show schematic diagrams of a typical embodiment of the process of the invention wherein the first solvent system and the second solvent system are the same.

[0105] FIGS. 3 and 4 show schematic diagrams of a typical embodiment of the process of the invention wherein the first solvent system and the second solvent system are different.

DESCRIPTION

[0106] FIG. 1 shows an example of the recycling process of the invention, wherein the solvent used for both the dye extraction step and polyester extraction steps is methyl benzoate. Packaging containing polyesters are comminuted and mixed with an excess of methyl benzoate and the reaction mixture is heated to a temperature in the range 90° C. to 100° C. for approximately 10 minutes in step i). The reaction material is then filtered and the dye containing methyl benzoate solution is isolated from the polyester mixture in step ii). The dye solution is evaporated under vacuum to separate the methyl benzoate solvent from the dissolved dyes in step vi). The extracted methyl benzoate is then available for recycling into the initial reaction vessel in step vii) or can be incorporated into the reaction mixture in step viii).

[0107] The polyester mixture is then reacted with methyl benzoate at a temperature of 120° C. to 130° C. for two hours until all at least 95% of the polyester has been dissolved in step iii). The resulting mixture is then filtered in step iv) to separate the methyl benzoate/polyester mixture from the remaining insoluble impurities. The polyester is the isolated by evaporating the methyl benzoate under vacuum in step v). The evaporated methyl benzoate is condensed and can then be reintroduced into the reaction mixture at step vii) or alternatively can be introduced into the reaction mixture at step viii).

[0108] FIG. 2 shows an example of the recycling process of the invention, wherein the solvent used for both the dye extraction step and polyester extraction steps is 1,3-dimethylimidazolidinone (hereafter referred to as “DMI”). Packaging containing polyesters are comminuted and mixed with an excess of DMI and the reaction mixture is heated to a temperature in the range 90° C. to 100° C. for approximately 10 minutes in step i). The reaction material is then filtered and the dye containing DMI solution is isolated from the polyester mixture in step ii). The dye solution is evaporated under vacuum to separate the DMI solvent from the dissolved dyes in step vi). The extracted DMI is then available for recycling into the initial reaction vessel in step vii) or can be incorporated into the reaction mixture in step viii).

[0109] The polyester mixture is then reacted with DMI at a temperature in the range 120° C. to 130° C. for two hours until all at least 95% of the polyester has been dissolved in step iii). The resulting mixture is then filtered in step iv) to separate the DMI/polyester mixture from the remaining insoluble impurities. The polyester is then isolated by evaporating the DMI under vacuum in step v). The evaporated DMI is condensed and can then be reintroduced into the process in step vii) or alternatively can be introduced into the reaction mixture in step viii).

[0110] FIG. 3 shows an example of the recycling process of the invention wherein the solvent used to extract the dyes is different to the solvent used to extract the polyester from the packaging. Packaging containing polyester are comminuted and mixed with an excess of ethyl acetate and the reaction mixture is heat to a temperature in the range 90° C. to 100° C. for approximately 10 minutes in step i). The reaction material is then filtered and the dye containing ethyl acetate solution is isolated from the polyester mixture in step ii). The dye solution is evaporated under vacuum to separate the ethyl acetate solvent from the dissolved dyes in step vi). The extracted ethyl acetate is then available for recycling into the initial reaction vessel in step vii).

[0111] The polyester mixture is then treated with methyl benzoate at a temperature of 120° C. to 130° C. for two hours until all at least 95% of the polyester has been dissolved in step iii). The resulting mixture is then filtered in step iv) to separate the methyl benzoate/polyester mixture from the remaining insoluble impurities. The polyester is the isolated by evaporating the methyl benzoate under vacuum in step v). The evaporated methyl benzoate is condensed and can then be reintroduced into the reaction mixture in step viii).

[0112] FIG. 4 shows an example of the recycling process of the invention wherein the solvent used to extract the dyes is different to the solvent used to extract the polyester from the garments. Garments containing polyester are comminuted and mixed with an excess of cyclohexanone and the reaction mixture is heated to a temperature in the range 90° C. to 100° C. for approximately 10 minutes in step i). The reaction material is then filtered and the dye containing cyclohexanone solution is isolated from the polyester mixture in step ii). The dye solution is evaporated under vacuum to separate the cyclohexanone solvent from the dissolved dyes in step vi). The extracted cyclohexanone is then available for recycling into the initial reaction vessel in step vii).

[0113] The polyester mixture is then reacted with 1,3-Dimethyl-2-imidazolidinone (DMI) at a temperature of 120° C. to 130° C. for two hours until all at least 95% of the polyester has been dissolved in step iii). The resulting mixture is then filtered in step iv) to separate the DMI/polyester mixture from the remaining insoluble impurities. The polyester is the isolated by evaporating the DMI under vacuum in step v). The evaporated DMI is condensed and can then be reintroduced into the reaction mixture in step viii).

EXAMPLES

Example 1—Dissolution of Bottle Grade Poly(Ethylene Terephthalate) (PET) in Ethyl Benzoate

[0114] Ethyl benzoate (>99%, Sigma Aldrich, 250 mL) was placed in a 1 litre round bottomed flask equipped with reflux condenser and magnetic stirrer and heated to 120° C. with stirring on a hot plate. Mixed post-consumer PET chip from plastic bottles (10 g, mixture of colourless, blue and green) was added to the solvent and the mixture was stirred for 30 minutes at 120° C. Over this period, the solvent was observed to turn green in colour owing to the leaching of dyestuffs. The PET was heavily permeated and swollen by the solvent but did not dissolve to a significant extent. The mixture was then heated to in the range 180-200° C. for a further 2 hours, with stirring, over which period the solid PET was observed to entirely dissolve, yielding a clear green solution. Heating was discontinued and the solution was allowed to cool to room temperature, whereupon it solidified into a waxy polymer-solvent gel phase of a pale blue-green colour. This material was transferred to a filter funnel and washed with a further 250 mL cold ethyl benzoate. The solid was then triturated with a large excess of cold 50% ethanol to remove solvent and dyestuffs. This yielded a pale greenish filtrate and a damp white semicrystalline solid (14.6 g) which was ground to a powder and dried at room temperature in vacuo over MgSO.sub.4 to yield 9.62 g of white solid.

Example 2—Dye Removal and Subsequent Dissolution of Post-Consumer Coloured Poly(Ethylene Terephthalet) (PET) Textile in 1,3-Dimethyl-2-Imidazolidinone (DMI)

[0115] 1,3-Dimethyl-2-imidazolidinone (DMI, >98%, FChemicals, 10 L) was placed in a 30 L glass jacketed reactor with overhead stirrer and condenser and heated to 100° C. with stirring. Mixed post-consumer 100% PET textile from shredded garments (500 g, mixture of white, red, purple, pink, blue, green and black) was added to the solvent and the mixture was stirred for 30 minutes at 100° C. Leaching of the dyestuffs into the solvent began immediately and was practically complete after 10 minutes. The textile was visibly swollen by the solvent but did not significantly dissolve, whilst the solvent became opaque and dark purple-black in colour. The hot solvent was then pumped off from the vessel, leaving the remaining textile as an off-white solid. Fresh solvent (10 L) was added to the vessel containing the polymer and heated to 160° C. with stirring for 1 hour, over which period the PET dissolved to give a pale yellow solution. This solution was hot-filtered and decanted into a 20 L Pyrex beaker, where it was allowed to return to room temperature. It was then washed with cold DMI (5 L) and subsequently with absolute ethanol (20 L) to remove residual solvent.