CA2261303C - Method for removing color from ionically dyeable polymeric materials - Google Patents
Method for removing color from ionically dyeable polymeric materials Download PDFInfo
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- CA2261303C CA2261303C CA002261303A CA2261303A CA2261303C CA 2261303 C CA2261303 C CA 2261303C CA 002261303 A CA002261303 A CA 002261303A CA 2261303 A CA2261303 A CA 2261303A CA 2261303 C CA2261303 C CA 2261303C
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W30/00—Technologies for solid waste management
- Y02W30/50—Reuse, recycling or recovery technologies
- Y02W30/62—Plastics recycling; Rubber recycling
Abstract
A method for removing color and extracting dyes from ionically dyeable polymeric materials is provided. The method includes contacting the ionically dyeable polymeric material with a swelling agent for the material under conditions sufficient to effect diffusion of the dye from the material. The process is especially useful for removing colors from ionically dyeable polymeric materials as part of a recycling process for such materials. Also, the extracted dye may be recovered for re-use as the swelling agent and contacting composition are substantially non-reactive with the dye.
Description
CA 02261303 1999-02-05 ~.~
~./ '...i i BACKGROUND OF THE INVENTION
~./ '...i i BACKGROUND OF THE INVENTION
s Field of the Invention 6 The present invention is directed to a method for removing color from ionically 7 dyeable polymeric material. The present invention is also directed to a method for a extracting dye from ionically dyeable polymeric material. More particularly, the present 9 invention is directed to a melhod for recycling colored polymeric znaterial which includes contacting the polymeric material with a swelling agent for the material to produce a ( i decolored, ionically dyeable polymeric material and forming an article therefrom.
12 Background 13 As the amount of available landfill space decreases, and the nunnber of articles 14 manufactured ftom synthetic polymers increases, there exists an unrzxet need for (s environmentally responsible methods for disposal of these polymer containing articles. A
16 welcome alternative to landfill disposal is recycling and reuse of the synthetic polymer 17 material in pzoducts which may be the same as or entirely different from the original la article.
19 One significant limitation to the utility of recycled synthetic polymer material is 20 the imparted color. Colorants or dyes are commonly added to virgin polymers for both 21 practical and aesthetic reasons. However, the colorant or dye may significantly impair 22 the processability of or degrade the polymer during conventional recycling processes.
u Further, the presence of colorant or dye may limit the potential downstream uses of the 24 recycled polymeric material as any color change desired in the downstream use could be 25 limited if not impossible given the original article's color. In a worst case scenario, a zt, article otherwise suitable for recycling would be rejected completely and deposited in a 27 landfill simply because its color is undesirable or i.rtappropriate for a particular 28 downstream use.
29 Processes fo.r stripping dyes from or decolorizing various materials are well 30 known in the an.. For example, U.S. Patent No. 4,227,881 discloses a process for FL 2310+5(4r9XOWDOCJ
=='~ ,r=..
stripping dyes from textile fabric which includes heating an aqueous solution of an 2 ammonium salt, a sulfite salt and an organac sulfonate to at least 140 F (60 C) and adding 3 the dyed fabric to the heated solution while maintaining the temperature of the solution.
a In addition to the costly heating and temperature maintenance scep, this process has the s drawback of producing fabrics which after processing exhibit a remaining color depth. [n 6 U.S. Patent No. 4,783,193 a process for stripping color from synthetic polymer products 7 by contacting the colored polymer with a chernical system is disclosed. The described R process uses unstable dispersions of alkyl halides and aqueous solutioms of 9 bleacliing/oxidizing agents to which specified quantities of acids and surfaetant/wetting to agents are added. Annong the drawbacks are the use of potentially hazardous halogens i I and the special provisions required to prevent escape of vapors which could cause 12 environmental harm. Further, the use of the chemical system may restrict or eliminate the 13 polymeric materials recyclability. In general, processes whuch utilize hars.h stripping -a agents destroy the usefulness of the colorant thus generating a chemical.
waste stream that is must be treated or disposed of in an envi=ronmentally conscious manner.
These methods i6 can also generate unremovable colorant,Fragments which limit the downstxeam 17 recycleability and utility of the color-stripped material.
1s Thus an unmet need exists for a cost-effective and environmentally friendly 19 process for removing color fro.m synthetic polymer materials which completely removes 20 the colorant from the material without degrading ar otherwise decreasing the material's or 21 the colorant's availability.for recycling and re-use.
24 The present invention is directed to a cost-effective a>ad enviro.nznentally friendly 25 process for removing color, including dye-imparted color and stains, from colored 26 io.nically dyeab.le polymeric materials. The process includes contacting the colored 27 material wit,h at least one swelling agent under conditions su;f;Iicient to effect diffusion of 28 the dye from the material. The process of the present invention is especially useful for 29 quickly and thoroughly xemoving colors from ionically dyeable polymeric materials as F~: ts~w~~=t~~GO~,DOC~
~ .v I part of a recycling process for such materials without substantially degrading either the 2 material or the dye, tbus allowing for their recove,y and reuse.
3 In one embodiment of the invention, a process for recycling colored polymeric 4 material comprises the step of contacting solid colored polymeric material with an s aqueous Ci-C1o alcohol solution at a temperature effective to cause swelling of the 6 polymeric material, whe.reby colorant is removed from the polymeric material, producing 7 a decolored polymeric material. This process is especially useful where the polymeric s material is a polyamide, for example an ionically dyed polyamide, such as post-consutner 9 carpet that contains dyed nylon fibers.
ln this embodiment of the invention, the colored polymeric material preferably is I ) contacted with the aqueous alcohol solution at a temperature between about 90-102 C.
12 Optionally, after the aqueous alcohol solution is contacted with the polymer, the solution 13 can be cooled to a temperature from about 20-75 C, preferably ambient temperature. If 14 the solution contains a surfactant in an effective amount, e.g., frotn about 2-5%, the is solution will then separate into distinct aqueous and alcohol phases, with the dye or other 16 colorant primarily in the alcohol phase.
17 The aqueous alco.hol solution preferably comprises at least about 50% by weight )s water and at least one alcohol selected from the grou.p cons1sting of benzyl alcohol, 19 methanol, ethanol, 1- and 2-propanol, 1-butanol, and cyclohexanol. In addition, the aqueous alcohol solution preferably also coniprises a surfactant at a coricentration 21 effective to cause the aqueous alcohol solution to be a single phase at the temperature at 22 which that solution is contacted with the colored polymeric material, and to separate into 23 two phases at a reduced temperature between about 20-75 C. Many surfactants could be 24 used for this purpose.
In one specific ernbodiment, the process can also include the additional step of 26 recovering colorant from the aqueous alcohol solution. Alternatively, o.r :in addition 27 thereto, the process can include the step of recovering the decolored polymerie material.
28 Optionally the decolored polymeric material can be washed subsequently with a 29 polar liquid. Preferred washing liquids include water, Ci-C4 aliphatic alcohols, C3-C6 ketones, and cni.xtures thereof.
B. i11M5(~Y~XOn.pO~) One particular embodiment of the invention is a process for recycling colored 2 polyamide material, comprising (1) contacting solid colored polyamide material with an aqueous solution that comprises (a) at least about 50% by weight water, (b) at least one 4 Cl-C,u alcohol, (c) a,urfactant in an amount effective to cause the solution to form a s single phase at a temperature between about 90-102 C, and to fonn two phases at a 6 temperature between about 20-75 C , and (d) a pH modifying agent effective to adjust the 7 pH of the solution to at least about 7, more preferably to at least about 11; thereby R causing swelling of the polyamide material and removal of colorant from the polyamude 9 material, producing a decolored polyarnide material; and (2) cooling the aqueous alcohol solution to a temperature between about 20-75 C, whereby the solution separates into an iI aqueous phase and an alcohol phase, more than 80% by weight of the colorant removed 12 from the polyarnide being contained in the alcohol phase.
13 If the colored polymeric material to be treated is post consumer carpet containing 14 colored nylon fibers, the process can optionally also comprise one or more of the is preliroinary steps of (l) physically separating carpet having nylon face fibers from carpet ) 6 having non-nylon face fibers; (2) prepurifying the carpet having nylon face fibers from step (1) by.mechanically separating dirt and other loosely-attached foreign materials and 18 washing the carpet with detcrgent and water; (3) separating the nylon face fibers from the 1,9 backing of the carpet by a method selected from the group consisting of shearing, cut-ting with a bot wire, cutting with a laser, and combinations thereof; and (4) grindi.ng, cutting, 21 or shearing the colored nylon fibers into particles having reduced size.
22 The present invention has a number of advantages over prior art decolorization 23 methods. The present invention does not substantially degrade the polymer and therefore 24 recovered polymer can be used in new polymeric materials or articles without the need is for repolymerization. The present invention can thoroughly remove a wide variety of 26 color-imparting agents hom the polymeric material., even if the colorants are deeply 27 penetrated into the polymeric material or are in the form of large aggregates inside voids 28 in the polymeric material.
29 Because the process of the present invention does not substantially degrade the dye or other colorant in the process of separating it from the polymer, t.he colorant itself H 23 1 Oe>(4Y9?(01 I DOC) ~.. ~~ =
i can. be .recovered and reused. Therefore, in different embodiments of the invention, the 2 process mig.ht.involve recovering only the polymer, recovering only the colorants, or 3 recovering both the polymer and the colorants for separate reuse.
BRIEF DESCRIPTION OF THE DRAWINGS
12 Background 13 As the amount of available landfill space decreases, and the nunnber of articles 14 manufactured ftom synthetic polymers increases, there exists an unrzxet need for (s environmentally responsible methods for disposal of these polymer containing articles. A
16 welcome alternative to landfill disposal is recycling and reuse of the synthetic polymer 17 material in pzoducts which may be the same as or entirely different from the original la article.
19 One significant limitation to the utility of recycled synthetic polymer material is 20 the imparted color. Colorants or dyes are commonly added to virgin polymers for both 21 practical and aesthetic reasons. However, the colorant or dye may significantly impair 22 the processability of or degrade the polymer during conventional recycling processes.
u Further, the presence of colorant or dye may limit the potential downstream uses of the 24 recycled polymeric material as any color change desired in the downstream use could be 25 limited if not impossible given the original article's color. In a worst case scenario, a zt, article otherwise suitable for recycling would be rejected completely and deposited in a 27 landfill simply because its color is undesirable or i.rtappropriate for a particular 28 downstream use.
29 Processes fo.r stripping dyes from or decolorizing various materials are well 30 known in the an.. For example, U.S. Patent No. 4,227,881 discloses a process for FL 2310+5(4r9XOWDOCJ
=='~ ,r=..
stripping dyes from textile fabric which includes heating an aqueous solution of an 2 ammonium salt, a sulfite salt and an organac sulfonate to at least 140 F (60 C) and adding 3 the dyed fabric to the heated solution while maintaining the temperature of the solution.
a In addition to the costly heating and temperature maintenance scep, this process has the s drawback of producing fabrics which after processing exhibit a remaining color depth. [n 6 U.S. Patent No. 4,783,193 a process for stripping color from synthetic polymer products 7 by contacting the colored polymer with a chernical system is disclosed. The described R process uses unstable dispersions of alkyl halides and aqueous solutioms of 9 bleacliing/oxidizing agents to which specified quantities of acids and surfaetant/wetting to agents are added. Annong the drawbacks are the use of potentially hazardous halogens i I and the special provisions required to prevent escape of vapors which could cause 12 environmental harm. Further, the use of the chemical system may restrict or eliminate the 13 polymeric materials recyclability. In general, processes whuch utilize hars.h stripping -a agents destroy the usefulness of the colorant thus generating a chemical.
waste stream that is must be treated or disposed of in an envi=ronmentally conscious manner.
These methods i6 can also generate unremovable colorant,Fragments which limit the downstxeam 17 recycleability and utility of the color-stripped material.
1s Thus an unmet need exists for a cost-effective and environmentally friendly 19 process for removing color fro.m synthetic polymer materials which completely removes 20 the colorant from the material without degrading ar otherwise decreasing the material's or 21 the colorant's availability.for recycling and re-use.
24 The present invention is directed to a cost-effective a>ad enviro.nznentally friendly 25 process for removing color, including dye-imparted color and stains, from colored 26 io.nically dyeab.le polymeric materials. The process includes contacting the colored 27 material wit,h at least one swelling agent under conditions su;f;Iicient to effect diffusion of 28 the dye from the material. The process of the present invention is especially useful for 29 quickly and thoroughly xemoving colors from ionically dyeable polymeric materials as F~: ts~w~~=t~~GO~,DOC~
~ .v I part of a recycling process for such materials without substantially degrading either the 2 material or the dye, tbus allowing for their recove,y and reuse.
3 In one embodiment of the invention, a process for recycling colored polymeric 4 material comprises the step of contacting solid colored polymeric material with an s aqueous Ci-C1o alcohol solution at a temperature effective to cause swelling of the 6 polymeric material, whe.reby colorant is removed from the polymeric material, producing 7 a decolored polymeric material. This process is especially useful where the polymeric s material is a polyamide, for example an ionically dyed polyamide, such as post-consutner 9 carpet that contains dyed nylon fibers.
ln this embodiment of the invention, the colored polymeric material preferably is I ) contacted with the aqueous alcohol solution at a temperature between about 90-102 C.
12 Optionally, after the aqueous alcohol solution is contacted with the polymer, the solution 13 can be cooled to a temperature from about 20-75 C, preferably ambient temperature. If 14 the solution contains a surfactant in an effective amount, e.g., frotn about 2-5%, the is solution will then separate into distinct aqueous and alcohol phases, with the dye or other 16 colorant primarily in the alcohol phase.
17 The aqueous alco.hol solution preferably comprises at least about 50% by weight )s water and at least one alcohol selected from the grou.p cons1sting of benzyl alcohol, 19 methanol, ethanol, 1- and 2-propanol, 1-butanol, and cyclohexanol. In addition, the aqueous alcohol solution preferably also coniprises a surfactant at a coricentration 21 effective to cause the aqueous alcohol solution to be a single phase at the temperature at 22 which that solution is contacted with the colored polymeric material, and to separate into 23 two phases at a reduced temperature between about 20-75 C. Many surfactants could be 24 used for this purpose.
In one specific ernbodiment, the process can also include the additional step of 26 recovering colorant from the aqueous alcohol solution. Alternatively, o.r :in addition 27 thereto, the process can include the step of recovering the decolored polymerie material.
28 Optionally the decolored polymeric material can be washed subsequently with a 29 polar liquid. Preferred washing liquids include water, Ci-C4 aliphatic alcohols, C3-C6 ketones, and cni.xtures thereof.
B. i11M5(~Y~XOn.pO~) One particular embodiment of the invention is a process for recycling colored 2 polyamide material, comprising (1) contacting solid colored polyamide material with an aqueous solution that comprises (a) at least about 50% by weight water, (b) at least one 4 Cl-C,u alcohol, (c) a,urfactant in an amount effective to cause the solution to form a s single phase at a temperature between about 90-102 C, and to fonn two phases at a 6 temperature between about 20-75 C , and (d) a pH modifying agent effective to adjust the 7 pH of the solution to at least about 7, more preferably to at least about 11; thereby R causing swelling of the polyamide material and removal of colorant from the polyamude 9 material, producing a decolored polyarnide material; and (2) cooling the aqueous alcohol solution to a temperature between about 20-75 C, whereby the solution separates into an iI aqueous phase and an alcohol phase, more than 80% by weight of the colorant removed 12 from the polyarnide being contained in the alcohol phase.
13 If the colored polymeric material to be treated is post consumer carpet containing 14 colored nylon fibers, the process can optionally also comprise one or more of the is preliroinary steps of (l) physically separating carpet having nylon face fibers from carpet ) 6 having non-nylon face fibers; (2) prepurifying the carpet having nylon face fibers from step (1) by.mechanically separating dirt and other loosely-attached foreign materials and 18 washing the carpet with detcrgent and water; (3) separating the nylon face fibers from the 1,9 backing of the carpet by a method selected from the group consisting of shearing, cut-ting with a bot wire, cutting with a laser, and combinations thereof; and (4) grindi.ng, cutting, 21 or shearing the colored nylon fibers into particles having reduced size.
22 The present invention has a number of advantages over prior art decolorization 23 methods. The present invention does not substantially degrade the polymer and therefore 24 recovered polymer can be used in new polymeric materials or articles without the need is for repolymerization. The present invention can thoroughly remove a wide variety of 26 color-imparting agents hom the polymeric material., even if the colorants are deeply 27 penetrated into the polymeric material or are in the form of large aggregates inside voids 28 in the polymeric material.
29 Because the process of the present invention does not substantially degrade the dye or other colorant in the process of separating it from the polymer, t.he colorant itself H 23 1 Oe>(4Y9?(01 I DOC) ~.. ~~ =
i can. be .recovered and reused. Therefore, in different embodiments of the invention, the 2 process mig.ht.involve recovering only the polymer, recovering only the colorants, or 3 recovering both the polymer and the colorants for separate reuse.
BRIEF DESCRIPTION OF THE DRAWINGS
6 These and other features of the present invention are more fully set fortb in the 7 following description of illustrative embodiments of the invention. The description is a presented with reference to the accompanying drawings in which:
9 FIG I is an illustration of an embodiment of a system suitable for practic.ing the io process of the present invention.
12 DETAILED DESCItIi''Z'IO:N OF SPECIFIC EMBODIMENTS
13 The following terms and phrases are used herein and are intended to have the 14 following nleaning:
is "color" is defined to include intentionally imparted visual appearance such as 16 color imparted by dyes and accidentally imparted visual appearance such as stains and the 17 like;
is "colorant" is defined as any dye, pigment or colored composition or combinations 19 thereof that may intentionally or accidentall.y color or stain ionically dyeable polymeric Zo materia]s;
21 "dye" is defined as an organic material which imparts color to a polymer and 22 which chemically bonds to the polymer primarily by ionic mechanisms;
23 "ionically dyeable polymeric material" is defined as any known ionically dyeable 24 polymer, copolymer, terpolyrner and the like as well as the blends or alloys the.reo,f;
2: "swelling agent", is defined as a material capable, under specified conditions, of 26 interrupting the molecular forces within the polymer matrix resulting iun an opening of its 27 structure.
2e All percentages herein are by weight unless otherwise specified.
29 The process of the present invention includes contacting a colored ionically 30 dyeable polymeric material with at least one swelling agent under conditions so as to H.:1W ioaS(aY9!(0Lt DCC) _ .~
effect the diffusion of a dye or other colorant from the polymeric material.
The amount 2 of the swelling agent and the conditions under which the contacting takes place are 3 selected so that neither the polymeric matezaal nor the dye undergo substantial destruction 4 or degradation. i.n, one embodiment, the amount of swelling agent and the conditions are s selected so that the general form or shape of the polymeric material is unaffected. In 6 another embodiment, the swelling agent and the conditions are selected so that the 7 polymer is solvated, and can be recovered from the swelling agent.
9 FIG I is an illustration of an embodiment of a system suitable for practic.ing the io process of the present invention.
12 DETAILED DESCItIi''Z'IO:N OF SPECIFIC EMBODIMENTS
13 The following terms and phrases are used herein and are intended to have the 14 following nleaning:
is "color" is defined to include intentionally imparted visual appearance such as 16 color imparted by dyes and accidentally imparted visual appearance such as stains and the 17 like;
is "colorant" is defined as any dye, pigment or colored composition or combinations 19 thereof that may intentionally or accidentall.y color or stain ionically dyeable polymeric Zo materia]s;
21 "dye" is defined as an organic material which imparts color to a polymer and 22 which chemically bonds to the polymer primarily by ionic mechanisms;
23 "ionically dyeable polymeric material" is defined as any known ionically dyeable 24 polymer, copolymer, terpolyrner and the like as well as the blends or alloys the.reo,f;
2: "swelling agent", is defined as a material capable, under specified conditions, of 26 interrupting the molecular forces within the polymer matrix resulting iun an opening of its 27 structure.
2e All percentages herein are by weight unless otherwise specified.
29 The process of the present invention includes contacting a colored ionically 30 dyeable polymeric material with at least one swelling agent under conditions so as to H.:1W ioaS(aY9!(0Lt DCC) _ .~
effect the diffusion of a dye or other colorant from the polymeric material.
The amount 2 of the swelling agent and the conditions under which the contacting takes place are 3 selected so that neither the polymeric matezaal nor the dye undergo substantial destruction 4 or degradation. i.n, one embodiment, the amount of swelling agent and the conditions are s selected so that the general form or shape of the polymeric material is unaffected. In 6 another embodiment, the swelling agent and the conditions are selected so that the 7 polymer is solvated, and can be recovered from the swelling agent.
8 lonically dyeable polymeric materials for which the process of the present 9 invention may be applied include polyamides, particularly nylons, more particularly to nylon 6,6, as -well as acrylics. Colored ionically dyeable polymer materials of the present i i invention are ionically dyeabl.e polymeric material5 rnodified by at least one dye or other 12 colorant.
13 Dyes for which the process of the present invention is particularly useful include )a acid dyes. Other dyes can also be removed using the process of the present invention.
15 Colorants for which thc process of the present invention is useful for inelude the above 16 mentioned dyes, but also natural and synthetic pigments, such as carbon black or colored 17 transition metal oxides, or colored compositions that may stain the ion.ically dyeable 18 poly.meric material. Examptes of such colored compositions include common food items 19 such as cofl'ee,1''ruit and vegetable material, juices and extracts, red wine and the like, 20 natural and synthetic inks, and other comrnon staining items.
21 The swelling agent used in the process of the present invention should be capable z of interrupting the molecular forces within the polymeric material matrix resulting in an 23 opening of its structure. 1n one embodiment of the present invention in which nylon 6,6 is 24 the aonacally dyeable polymeric material, the swelling agent may be any material known 2; to be capable of swelling nylon 6,6. Suitable swelling agents for this embodiment 26 include C~ to Cio alcohols and more particularly swelling agents include alcohols selected V from the group including benzyl alcohol, methanol, ethanol, I-, and 2-propamol, 1-ia butanol, cyclohexanol and the like, as well as mixtuzes, solutions, ennulsions or 29 dispersions thereof. Benzyl alcohol is a particularly preferred swelling agent when the 30 ionically dyeable polymeric material is nylon 6,6. Another particularly preferred I1. ~1015(oY9X01!.pOC) i swelling agent that solvates the polymer under conditions of elevated temperature and 2 pressure, and precipitates or recrystallizes a substantially pure polymer under a ambient 3 pressure and temperacure is ethanol. Yet a third particularly preferred swelling agent thaz 4 solvates the polymer under conditions of elevated temperature and pressure and precipitates the polymer upon cooli.ng and removal of pressure is n-butanol.
6 In certain embodiments of the present invention, the swelling agent may be part of 7 a contacting composition in which the swelling agent is at least partially zniscible with the s other components in the contacting composition during the contacting step.
One 9 preferable contacting composition includes an aqueous component in addition to the io swelling agent. More preferably, the swelling agent is present in an amount of at least i i about 10% by weight based on the total weight of the contacting composition. It should 12 be apparent to one of ordinary skill in the art that the exact amount of swell.iung agent 13 utilized in. the contacting composition will vary depending upon the conditions, such as 14 temperature, pressure, pH value, residency ti.me and so forth, utilized during the 1s contacting step. In embodiments where the dye is to be re-used, it sbould also be kept in 16 mind that the contacting composition should preferably be substantially non-reactive with the dye.
1e It was unexpectedly discovered that a dye or other colorant can be substantially 19 removed froni ionically dyeable polymeric materials by contacting the materials with a 20 suitable swelling agent under conditions which effect the diffusion of dye from the 21 polymer. Thus the swelling agent in the contacting composition and the conditions of the 22 contacting step should allow for the diffusion of the dye or colorant from the ionical.ly 23 dyeable polymeric material into the contacting composition. Further these conditions 24 allow for the separation of the decolorized polymeric material from the dye or colorant 25 containing contacting composition. In one preferred embodiment, the ionically dyeable 26 polymeric material is colored by at least one dye which once removed from the polymer 27 using the process of the present invention can be recovered from the contacting 28 composition and the dye recycled and reused. In another embodiment of the present 79 invention, the ionically dyeable polymeric material is colored by a mixture of dyes and 30 colorants in the form of stains. Upon removal 'from the polymer using the processof the H. ~~as~4ra~ro~!.ooc) CA 02261303 1999-02-05 f-, '. ' ..f L present invention, the polymeric material is recycled or reused and a concentrated mixture 2 of dyes and various colorants is recovered from the contacting composition after which it 3 is disposed. of in an environmentally conscious manner. In a third embodiment of the 4 present invention, the polymer is selectively solvated by the swelling agent, the polymer s containing contacting composition is separated from the insoluble material, and a 6 substantially pure polymer material is recovered by precipitation or recrystallization.
7 As noted above, the conditions of the contacting step should provide a driving e force or mechanism by which the diffusion of the dye from the polymer to the contacting L) composition is favored. One manner of doing this is to formulate the contacting composition so that during the contacting step the contacting composition has a suitable I i pl i value. In an embodiment wherein the colorant is an acid dye, the contarting 12 composition is formu]ated to include a pH modifying agent so that the contacting step is 1.3 preferably conducted at a pH value of at least about 7 and more preferably at a, pH value 14 of at least about 11.
Suitable pH modifying agents should be selected so as to be at least panially 16 soluble in the contacting composition and be present in an am.ount sufficient to maint.ain 17 the desired pH value. In embodiments wr ere the contacting step is conducted at a pH
11 value of at least about 7, suitable pH modifying agents may be selected from the group 19 including alkali metal hydroxides, alkali metal oxides, trialkylalcobol amines, alkyldiarnines, dialkylamides, and mix.tures thereof. In a more preferred embodiment, the 21 pH modifying agent is selected from the group including sodiiun hydroxide, potassium 22 hydroxide, sodium oxide, potassium oxide, trialkylalcohol amines having C, to C4 alkyl v groups, C, to C8 alkyldiamines, dialkylacetamides having Ci to C. alkyl groups and 24 mixture thereof zs It should be app.reciated by one of ordinary skill in the art that the amount of 26 swelling agent and the amount of pH modifying agent in the contacting compos:ition will 27 depend upon the desired conditions of the contacting step and with each other. Putther 28 variables such as the polymeric material, the nature and amounts of the dye(s) or 29 colorant(s) present in the polymer, the depth of color shade and the like will need to be considered. However, such optimization of exact amounts and conditions should be H. .'3I OASteV 9?(01 !.DOC) CA 02261303 1999-02-05 ,- ~
...i .~
i apparent given the present disclosure, and as such are considered to be within the scope 2 of the present invention.
3 The temperature and pressure at which the contacting step should be carried out a will depend upon the polymer or blend of polymers that constitute the colored ionically ; dyeable polymeric material. It is preferred that the contacting step be carried out at a 6 tempeTature of at least above the solution glass transition temperature (Ts) of the colored 7 polymeric material in the process environment (i.e., in the presence of the liquid s contacting composition). It should be recognized that the glass transition temperature 9 changes when liquid is contacted with the polymer. In one preferred embodiment the temperatures are at least about 10 C and no greater than about 250 C. In another 11 prefetred embodiment, the contacting step is carried out at a temperature of at least about 12 20 C, and more particularly at temperature of at least about 97 C.
13 The contacting step is preferably performed at ambient or greater pressure.
1 a Applied pressure may be that provided by an inert gas, such as nitrogen or argon, or it is may be the pressure generated by the vaporization of the liquids in the contacting 16 composition. In one embodiment, the contacting step is carried out at a pressure of about 17 1 atmosphere to about 2 atmospheres and more preferably a pressure of about 1.0 18 atmospheze to about 1.5 atmospheres. In another embodiment the pressure was that -9 generated by the vaporization of heating the contacting composition .in a sealed container.
As will be apparent to one skilled in the art, the combined effect of temperature 21 and pressure and the formulation of a suitable contacting composition can be used to u control the processes of the present invention. Thus variation and optimization of the 23 contacting composition, and the temperature and pressure conditions of the contacting 24 process in order to maximize the decolozizimg effect of the contacting composition are considered to be within the scope of the present invention. It should be noted that if the 26 process is conducted at ambient pressure, only swelling agents such as alcohols that boil 27 at relatively high temperatures can be used.
29 The form of the ionically dyeable polymeric material may be selected or modified 29 to maximize the surface area of the ionically dyeable material available for contact with the contacting composition. The residence time for contacting ch.e ionically dyeable '10 N: nl0a5(+Y9z01.DOC) ... =,~
i polymeric material witli the contacting composition. during the contacting step may be 2 controlled to ensure the desired degree of color removal. Suitable residence times for the 3 contacting step will depend upon the conditions of the contacting step. The preferred 4 residence time is at least about 1/2 minute and no greater than about 20 minutes, more s preferably about % to 1 minute. The contacting step in these elxtbodiments may include a 6 plurality of contacting stages wherein the ioiucally dyeable polymeric matenal is 7 contacted with the swelling agent at each. stage. In embodiments where the solvatiou of 8 the polymeric material is desired, a preferred residence time may be about 10 minutes or 9 greater. Therefore one skilled in the art would appreciate that the residence time varies io depending on the temperature, pressure and other conditions io, order to achieve the iI resu]ts of the present invention.
12 Preferably, the contacting step is conducted in the presence of at least one i a surfactant, and moie preferably in an amount of at least 2% by weight based on the total 14 weight of the contacting composition. Suitable surfactants include nonionic, anionic, and 15 cationic surfactants. .Particularly preferred sLWfaetants include trialkylalcoho) phosphate 16 salts such as the potassium salt of tridecylalcohol phosphate to which 6 moles of ethylene 17 oxide has been added. This compound is commercially available fronn Ethox Cotp. as 18 ETH. FAC 363 (TM). In embodiments of the process where an alcohol in the contacting -9 composition is not readily soluble in water, the surfactant may be combined with the 20 swel.ling agent as part of the contacting composition such that the swelling agent is 21 substantially miscible in the contacting composition during the contacting step.
22 In one embodime.nt, the process of the present invention further includes 23 recovering the dye from the contacting composition for recycling and re-use. Thus it has :.4 been unexpectedly discovered that the contacting step can result in a dye-containing 25 contacting composition from which the dye can be. recovered and subsequently re-used to 26 again color polymeric materials. Suitable techniques or methods of recovery include, for 27 example, ion exchange, ultrafiltration, selective precipitation, countet current extraction 28 or other extraction techniques and the like. Choice of the appropriate recovery method 29 will depend on the characteristics of the dye and the formulation of the contacting 30 composition and will be readily apparen't to one of ordinary skill in the art.
13 Dyes for which the process of the present invention is particularly useful include )a acid dyes. Other dyes can also be removed using the process of the present invention.
15 Colorants for which thc process of the present invention is useful for inelude the above 16 mentioned dyes, but also natural and synthetic pigments, such as carbon black or colored 17 transition metal oxides, or colored compositions that may stain the ion.ically dyeable 18 poly.meric material. Examptes of such colored compositions include common food items 19 such as cofl'ee,1''ruit and vegetable material, juices and extracts, red wine and the like, 20 natural and synthetic inks, and other comrnon staining items.
21 The swelling agent used in the process of the present invention should be capable z of interrupting the molecular forces within the polymeric material matrix resulting in an 23 opening of its structure. 1n one embodiment of the present invention in which nylon 6,6 is 24 the aonacally dyeable polymeric material, the swelling agent may be any material known 2; to be capable of swelling nylon 6,6. Suitable swelling agents for this embodiment 26 include C~ to Cio alcohols and more particularly swelling agents include alcohols selected V from the group including benzyl alcohol, methanol, ethanol, I-, and 2-propamol, 1-ia butanol, cyclohexanol and the like, as well as mixtuzes, solutions, ennulsions or 29 dispersions thereof. Benzyl alcohol is a particularly preferred swelling agent when the 30 ionically dyeable polymeric material is nylon 6,6. Another particularly preferred I1. ~1015(oY9X01!.pOC) i swelling agent that solvates the polymer under conditions of elevated temperature and 2 pressure, and precipitates or recrystallizes a substantially pure polymer under a ambient 3 pressure and temperacure is ethanol. Yet a third particularly preferred swelling agent thaz 4 solvates the polymer under conditions of elevated temperature and pressure and precipitates the polymer upon cooli.ng and removal of pressure is n-butanol.
6 In certain embodiments of the present invention, the swelling agent may be part of 7 a contacting composition in which the swelling agent is at least partially zniscible with the s other components in the contacting composition during the contacting step.
One 9 preferable contacting composition includes an aqueous component in addition to the io swelling agent. More preferably, the swelling agent is present in an amount of at least i i about 10% by weight based on the total weight of the contacting composition. It should 12 be apparent to one of ordinary skill in the art that the exact amount of swell.iung agent 13 utilized in. the contacting composition will vary depending upon the conditions, such as 14 temperature, pressure, pH value, residency ti.me and so forth, utilized during the 1s contacting step. In embodiments where the dye is to be re-used, it sbould also be kept in 16 mind that the contacting composition should preferably be substantially non-reactive with the dye.
1e It was unexpectedly discovered that a dye or other colorant can be substantially 19 removed froni ionically dyeable polymeric materials by contacting the materials with a 20 suitable swelling agent under conditions which effect the diffusion of dye from the 21 polymer. Thus the swelling agent in the contacting composition and the conditions of the 22 contacting step should allow for the diffusion of the dye or colorant from the ionical.ly 23 dyeable polymeric material into the contacting composition. Further these conditions 24 allow for the separation of the decolorized polymeric material from the dye or colorant 25 containing contacting composition. In one preferred embodiment, the ionically dyeable 26 polymeric material is colored by at least one dye which once removed from the polymer 27 using the process of the present invention can be recovered from the contacting 28 composition and the dye recycled and reused. In another embodiment of the present 79 invention, the ionically dyeable polymeric material is colored by a mixture of dyes and 30 colorants in the form of stains. Upon removal 'from the polymer using the processof the H. ~~as~4ra~ro~!.ooc) CA 02261303 1999-02-05 f-, '. ' ..f L present invention, the polymeric material is recycled or reused and a concentrated mixture 2 of dyes and various colorants is recovered from the contacting composition after which it 3 is disposed. of in an environmentally conscious manner. In a third embodiment of the 4 present invention, the polymer is selectively solvated by the swelling agent, the polymer s containing contacting composition is separated from the insoluble material, and a 6 substantially pure polymer material is recovered by precipitation or recrystallization.
7 As noted above, the conditions of the contacting step should provide a driving e force or mechanism by which the diffusion of the dye from the polymer to the contacting L) composition is favored. One manner of doing this is to formulate the contacting composition so that during the contacting step the contacting composition has a suitable I i pl i value. In an embodiment wherein the colorant is an acid dye, the contarting 12 composition is formu]ated to include a pH modifying agent so that the contacting step is 1.3 preferably conducted at a pH value of at least about 7 and more preferably at a, pH value 14 of at least about 11.
Suitable pH modifying agents should be selected so as to be at least panially 16 soluble in the contacting composition and be present in an am.ount sufficient to maint.ain 17 the desired pH value. In embodiments wr ere the contacting step is conducted at a pH
11 value of at least about 7, suitable pH modifying agents may be selected from the group 19 including alkali metal hydroxides, alkali metal oxides, trialkylalcobol amines, alkyldiarnines, dialkylamides, and mix.tures thereof. In a more preferred embodiment, the 21 pH modifying agent is selected from the group including sodiiun hydroxide, potassium 22 hydroxide, sodium oxide, potassium oxide, trialkylalcohol amines having C, to C4 alkyl v groups, C, to C8 alkyldiamines, dialkylacetamides having Ci to C. alkyl groups and 24 mixture thereof zs It should be app.reciated by one of ordinary skill in the art that the amount of 26 swelling agent and the amount of pH modifying agent in the contacting compos:ition will 27 depend upon the desired conditions of the contacting step and with each other. Putther 28 variables such as the polymeric material, the nature and amounts of the dye(s) or 29 colorant(s) present in the polymer, the depth of color shade and the like will need to be considered. However, such optimization of exact amounts and conditions should be H. .'3I OASteV 9?(01 !.DOC) CA 02261303 1999-02-05 ,- ~
...i .~
i apparent given the present disclosure, and as such are considered to be within the scope 2 of the present invention.
3 The temperature and pressure at which the contacting step should be carried out a will depend upon the polymer or blend of polymers that constitute the colored ionically ; dyeable polymeric material. It is preferred that the contacting step be carried out at a 6 tempeTature of at least above the solution glass transition temperature (Ts) of the colored 7 polymeric material in the process environment (i.e., in the presence of the liquid s contacting composition). It should be recognized that the glass transition temperature 9 changes when liquid is contacted with the polymer. In one preferred embodiment the temperatures are at least about 10 C and no greater than about 250 C. In another 11 prefetred embodiment, the contacting step is carried out at a temperature of at least about 12 20 C, and more particularly at temperature of at least about 97 C.
13 The contacting step is preferably performed at ambient or greater pressure.
1 a Applied pressure may be that provided by an inert gas, such as nitrogen or argon, or it is may be the pressure generated by the vaporization of the liquids in the contacting 16 composition. In one embodiment, the contacting step is carried out at a pressure of about 17 1 atmosphere to about 2 atmospheres and more preferably a pressure of about 1.0 18 atmospheze to about 1.5 atmospheres. In another embodiment the pressure was that -9 generated by the vaporization of heating the contacting composition .in a sealed container.
As will be apparent to one skilled in the art, the combined effect of temperature 21 and pressure and the formulation of a suitable contacting composition can be used to u control the processes of the present invention. Thus variation and optimization of the 23 contacting composition, and the temperature and pressure conditions of the contacting 24 process in order to maximize the decolozizimg effect of the contacting composition are considered to be within the scope of the present invention. It should be noted that if the 26 process is conducted at ambient pressure, only swelling agents such as alcohols that boil 27 at relatively high temperatures can be used.
29 The form of the ionically dyeable polymeric material may be selected or modified 29 to maximize the surface area of the ionically dyeable material available for contact with the contacting composition. The residence time for contacting ch.e ionically dyeable '10 N: nl0a5(+Y9z01.DOC) ... =,~
i polymeric material witli the contacting composition. during the contacting step may be 2 controlled to ensure the desired degree of color removal. Suitable residence times for the 3 contacting step will depend upon the conditions of the contacting step. The preferred 4 residence time is at least about 1/2 minute and no greater than about 20 minutes, more s preferably about % to 1 minute. The contacting step in these elxtbodiments may include a 6 plurality of contacting stages wherein the ioiucally dyeable polymeric matenal is 7 contacted with the swelling agent at each. stage. In embodiments where the solvatiou of 8 the polymeric material is desired, a preferred residence time may be about 10 minutes or 9 greater. Therefore one skilled in the art would appreciate that the residence time varies io depending on the temperature, pressure and other conditions io, order to achieve the iI resu]ts of the present invention.
12 Preferably, the contacting step is conducted in the presence of at least one i a surfactant, and moie preferably in an amount of at least 2% by weight based on the total 14 weight of the contacting composition. Suitable surfactants include nonionic, anionic, and 15 cationic surfactants. .Particularly preferred sLWfaetants include trialkylalcoho) phosphate 16 salts such as the potassium salt of tridecylalcohol phosphate to which 6 moles of ethylene 17 oxide has been added. This compound is commercially available fronn Ethox Cotp. as 18 ETH. FAC 363 (TM). In embodiments of the process where an alcohol in the contacting -9 composition is not readily soluble in water, the surfactant may be combined with the 20 swel.ling agent as part of the contacting composition such that the swelling agent is 21 substantially miscible in the contacting composition during the contacting step.
22 In one embodime.nt, the process of the present invention further includes 23 recovering the dye from the contacting composition for recycling and re-use. Thus it has :.4 been unexpectedly discovered that the contacting step can result in a dye-containing 25 contacting composition from which the dye can be. recovered and subsequently re-used to 26 again color polymeric materials. Suitable techniques or methods of recovery include, for 27 example, ion exchange, ultrafiltration, selective precipitation, countet current extraction 28 or other extraction techniques and the like. Choice of the appropriate recovery method 29 will depend on the characteristics of the dye and the formulation of the contacting 30 composition and will be readily apparen't to one of ordinary skill in the art.
N~ ].110e5(4Y9XD1 I DOC) CA 02261303 1999-02-05 /-~
.._. ' w i One of the several aspects of the process of the present invention, is the selection 2 of the nature and amount of the swelling agent and optimization of the conditions under 3 which the contacting step is conducted so as to allow the swelling of the ionically dyeable a polymeric material without substantial dissolution or degradation of the material during s the contacting step. The terrn "swell", as utilized herein, is defined as the opening of the 6 ionically dyeable polymeric material matrix. When conducted in accordance to this 7 embodiment, the general shape and integrity of the form of the ionically d.yeable s polymeric material, for example fiber, molded part or the like, is maintained during the 9 contacting step. Again, it should be appreciated by one of ordinary skill in the art that the io amount of swelling agent and the conditions of the contacting step may vary as they are i i influenced by each other as well as external variables such as the ionically dyeable 12 polymezic material, the nature of the dye(s) or colorants present in the polymeric 13 material, the color, and the depth of color shade and the like as noted above.
-a Anotller aspect of the process of the present invention permits the rapid extraction 1s of dyes and other colorants thus substantially reinoving the color from ionically dyeable 16 polymeric materials without the need for harsh stripping agents. Stripping agents are 17 defined herein as materials which oxidize, reduce or otherwise destroy the dye i R chromophore. As noted above, because of the highly reactive eiternical nature of such 19 stripping agents, their use can limit or prevent the recycli.ng and reuse of the resulting 20 decolored polymeric material. The contacting step in the process of the present invention 2i is preferably conducted in the absence of such stripping agents. Thus the resulting 2-1 polymeric material can fully replace or be blended with virgin polymer .for use in articles 23 that conventionally decolo.rized polymer.ic material cannot presently be used.
24 The process of the present invention may further include a washing step, wherein 25 any residual dye, colorant, or swelling agent is rernoved. Suitable washing agents should 26 at least partially solubilize the residual dye, colorant or swelling agent without harm to 27 the decolori2ed ionically dyeable polymeric material. Washing agents should be polar 28 liquids and preferably are selected from the group including water, Ci to C4 aliphatic 29 alcohols, C3 to C6 ketones and mixtures thereof and more preferably selected from the 30 group including water, acetone and mixtures thereoF
N E7 io45(=Y9xoi I DOC) _ ~..
The contacting step may be perforrned using a variety of techni.ques that will be a apparent to one of ordinary skill in the art. Such techniques include immersing the 3 ionically dyeable polymeric material in the swelling agent, applying an effective a,mount a of the swelling agent onto the polymeric material, coating an effective amount of swelling agent onto the polymeric material, spraying an effective amount of swelling agent onto 6 the po(ymeric material and other similar such techniques. Further the contacting step 7 may be carried out in lots in a batch-wise manner or it may be carried out in a continuous 8 manner.
9 An ernbodiment of a system useful for performing the process of the present invention in a continuous manner is illustrated in FIG 1. In the embodiment shown, the i process includes providing a colored ionicatly dyeable polymerie material 10, shown here 12 as fibers modified with at least one dye. forming a loosely organized mat 15 of polymeric 13 material 10 having a top 20 and a bottom 25, and contacting the mat 15 vvith a contacting la composition 30 which includes a swelling agent at a plurality (exemplified herein as three) of stages 35 so as to swell and decolorize the colored ionically dyeable polymeric 16 material. 1'referably and as shown, the contacting composition 30 is supplied, collected 17 and recirculated by suitable means such as piping 32 so as to contact the mat 15 of 18 polymeric material at each successive stage 35 in a counter current direetion. The mat 15 1v of polymeric material may be forrned or placed on a traveling belt 40 which is at least partially permeable to, but not chemically affected by, the contacting composition 30.
21 The substantially decolorized polymeric fibers are collected at collector 45 while the dye 22 55 in the dye-containing contacting composition 50 is recovered by a suitable separator 23 60 as described above. Once the dye is separated from the contacting composition, the 24 contacting composition is reused in the process.
zs Sinviar suitable devices and techniques for performing the process of the present 26 invention as described above are known in the diverse art of paper pulp washing. Such 27 technology is exemplified in U.S. Patent No.: 5,275,024; 4,539,827;
4,046,621 =
28 A commercially available example is sold under the tradename CHEMIWASHER
29 which is CA 02261303 2007-04-30 ~., t a horizontal pulp washer, commercially available hom Black-Clawson Pulp and Paper 2 Machinery Group.
3 The method of the present invention can use a contacting composition (also 13 referred to as a decolorization forrnulation) that will remain a single liquid phase during s the treatment of the colored polymeric material and subsequent recovery steps. However, 6 it is preferred to use a decolorization formulation that will be a single liquid phase at the 7 temperature at which the polymeric material is treated, but will form two distinct liquid s phases at the lower temperature at which the subsequent recovery steps are conducted.
9 Such a two-phase decolorization formulation makes recovery of the dye and/or polymer io si.mpler.
i t An example of a decolorization formulation that will remain a single phase at both rz temperatures is:
13 water 60%
ia benzyl alcohol 20 /a 15 aminomethyl propanol (for pH adjustment) 10%
16 EthfacTM 363 (surfactant) 10%
17 (Ethfac 363 is tridecylalcohol phosphate with 6 moles ethylene oxide, potassium salt.) I* An example of a suitable two phase solution is similar to the above solution but 14 with the Ethfac content reduced to 5% and the water content increased to make up the 20 difference. This solution fornis two phases below about 35 C. Lower levels of surfactant 21 increase the temperature at which the conversion fYom two phase to single phase occurs.
zZ However, complete elimination of the surfactant can result in two phases forming at the 23 preferred polymer treatment te.mperature (e.g-, about 100 C), which can cause the 24 polymer to dissolve in the alcohol, which is not desired.
is The pre:ferred goal in this embodiment of the invention is to use a decoloriza.tion 26 formulation that will fontn two distinct phases at about ambient temperature for easy 27 recovery of the dye and/or the polymer in the alcohol or aqueous phases, respectively.
29 The dye can be salted out from the alcohol by the addition of a salt such as NaCI, and 29 separation can be accomplished by decanting.
In an especially preferred embodiment, dyed nylon fiber is contacted with the 2 decolorization formulation at temperature of at least about 98 C for a period of about 0.5 3 - 5 minutes. For batch operation, a series of two or three treatments will improve the 4 final polymer product color. A continuous count.erElow operation, as described above, is preferred. The addition of sodium hydrosulfite at 0.2% of solution, or at higher levels as 6 an, after treatment wash, can also enhance final polymer color. However, the sodium 7 hydrosulfite degrades rapidly in water and loses its effectiveness in. only 2-3 .minutes.
s The following examples are included to demonstrate preferred embodiments of 4 the invention. It should be appreciated by those of skill in the art that the techniques -o disclosed in the examples which follow represent techniques discovejed by the inventors i to function well in the practice of the invention, and thus can be considered to constitute iz preferred modes fo.r its practice. However, those of skill in the art should, in light of the 13 present disclosure, appreciate that many changes can be nrade in the specific 14 embodiments which are disclosed and still obtain a like or simila.r result without 15 departing from the spirit and scope of the invention.
.._. ' w i One of the several aspects of the process of the present invention, is the selection 2 of the nature and amount of the swelling agent and optimization of the conditions under 3 which the contacting step is conducted so as to allow the swelling of the ionically dyeable a polymeric material without substantial dissolution or degradation of the material during s the contacting step. The terrn "swell", as utilized herein, is defined as the opening of the 6 ionically dyeable polymeric material matrix. When conducted in accordance to this 7 embodiment, the general shape and integrity of the form of the ionically d.yeable s polymeric material, for example fiber, molded part or the like, is maintained during the 9 contacting step. Again, it should be appreciated by one of ordinary skill in the art that the io amount of swelling agent and the conditions of the contacting step may vary as they are i i influenced by each other as well as external variables such as the ionically dyeable 12 polymezic material, the nature of the dye(s) or colorants present in the polymeric 13 material, the color, and the depth of color shade and the like as noted above.
-a Anotller aspect of the process of the present invention permits the rapid extraction 1s of dyes and other colorants thus substantially reinoving the color from ionically dyeable 16 polymeric materials without the need for harsh stripping agents. Stripping agents are 17 defined herein as materials which oxidize, reduce or otherwise destroy the dye i R chromophore. As noted above, because of the highly reactive eiternical nature of such 19 stripping agents, their use can limit or prevent the recycli.ng and reuse of the resulting 20 decolored polymeric material. The contacting step in the process of the present invention 2i is preferably conducted in the absence of such stripping agents. Thus the resulting 2-1 polymeric material can fully replace or be blended with virgin polymer .for use in articles 23 that conventionally decolo.rized polymer.ic material cannot presently be used.
24 The process of the present invention may further include a washing step, wherein 25 any residual dye, colorant, or swelling agent is rernoved. Suitable washing agents should 26 at least partially solubilize the residual dye, colorant or swelling agent without harm to 27 the decolori2ed ionically dyeable polymeric material. Washing agents should be polar 28 liquids and preferably are selected from the group including water, Ci to C4 aliphatic 29 alcohols, C3 to C6 ketones and mixtures thereof and more preferably selected from the 30 group including water, acetone and mixtures thereoF
N E7 io45(=Y9xoi I DOC) _ ~..
The contacting step may be perforrned using a variety of techni.ques that will be a apparent to one of ordinary skill in the art. Such techniques include immersing the 3 ionically dyeable polymeric material in the swelling agent, applying an effective a,mount a of the swelling agent onto the polymeric material, coating an effective amount of swelling agent onto the polymeric material, spraying an effective amount of swelling agent onto 6 the po(ymeric material and other similar such techniques. Further the contacting step 7 may be carried out in lots in a batch-wise manner or it may be carried out in a continuous 8 manner.
9 An ernbodiment of a system useful for performing the process of the present invention in a continuous manner is illustrated in FIG 1. In the embodiment shown, the i process includes providing a colored ionicatly dyeable polymerie material 10, shown here 12 as fibers modified with at least one dye. forming a loosely organized mat 15 of polymeric 13 material 10 having a top 20 and a bottom 25, and contacting the mat 15 vvith a contacting la composition 30 which includes a swelling agent at a plurality (exemplified herein as three) of stages 35 so as to swell and decolorize the colored ionically dyeable polymeric 16 material. 1'referably and as shown, the contacting composition 30 is supplied, collected 17 and recirculated by suitable means such as piping 32 so as to contact the mat 15 of 18 polymeric material at each successive stage 35 in a counter current direetion. The mat 15 1v of polymeric material may be forrned or placed on a traveling belt 40 which is at least partially permeable to, but not chemically affected by, the contacting composition 30.
21 The substantially decolorized polymeric fibers are collected at collector 45 while the dye 22 55 in the dye-containing contacting composition 50 is recovered by a suitable separator 23 60 as described above. Once the dye is separated from the contacting composition, the 24 contacting composition is reused in the process.
zs Sinviar suitable devices and techniques for performing the process of the present 26 invention as described above are known in the diverse art of paper pulp washing. Such 27 technology is exemplified in U.S. Patent No.: 5,275,024; 4,539,827;
4,046,621 =
28 A commercially available example is sold under the tradename CHEMIWASHER
29 which is CA 02261303 2007-04-30 ~., t a horizontal pulp washer, commercially available hom Black-Clawson Pulp and Paper 2 Machinery Group.
3 The method of the present invention can use a contacting composition (also 13 referred to as a decolorization forrnulation) that will remain a single liquid phase during s the treatment of the colored polymeric material and subsequent recovery steps. However, 6 it is preferred to use a decolorization formulation that will be a single liquid phase at the 7 temperature at which the polymeric material is treated, but will form two distinct liquid s phases at the lower temperature at which the subsequent recovery steps are conducted.
9 Such a two-phase decolorization formulation makes recovery of the dye and/or polymer io si.mpler.
i t An example of a decolorization formulation that will remain a single phase at both rz temperatures is:
13 water 60%
ia benzyl alcohol 20 /a 15 aminomethyl propanol (for pH adjustment) 10%
16 EthfacTM 363 (surfactant) 10%
17 (Ethfac 363 is tridecylalcohol phosphate with 6 moles ethylene oxide, potassium salt.) I* An example of a suitable two phase solution is similar to the above solution but 14 with the Ethfac content reduced to 5% and the water content increased to make up the 20 difference. This solution fornis two phases below about 35 C. Lower levels of surfactant 21 increase the temperature at which the conversion fYom two phase to single phase occurs.
zZ However, complete elimination of the surfactant can result in two phases forming at the 23 preferred polymer treatment te.mperature (e.g-, about 100 C), which can cause the 24 polymer to dissolve in the alcohol, which is not desired.
is The pre:ferred goal in this embodiment of the invention is to use a decoloriza.tion 26 formulation that will fontn two distinct phases at about ambient temperature for easy 27 recovery of the dye and/or the polymer in the alcohol or aqueous phases, respectively.
29 The dye can be salted out from the alcohol by the addition of a salt such as NaCI, and 29 separation can be accomplished by decanting.
In an especially preferred embodiment, dyed nylon fiber is contacted with the 2 decolorization formulation at temperature of at least about 98 C for a period of about 0.5 3 - 5 minutes. For batch operation, a series of two or three treatments will improve the 4 final polymer product color. A continuous count.erElow operation, as described above, is preferred. The addition of sodium hydrosulfite at 0.2% of solution, or at higher levels as 6 an, after treatment wash, can also enhance final polymer color. However, the sodium 7 hydrosulfite degrades rapidly in water and loses its effectiveness in. only 2-3 .minutes.
s The following examples are included to demonstrate preferred embodiments of 4 the invention. It should be appreciated by those of skill in the art that the techniques -o disclosed in the examples which follow represent techniques discovejed by the inventors i to function well in the practice of the invention, and thus can be considered to constitute iz preferred modes fo.r its practice. However, those of skill in the art should, in light of the 13 present disclosure, appreciate that many changes can be nrade in the specific 14 embodiments which are disclosed and still obtain a like or simila.r result without 15 departing from the spirit and scope of the invention.
17 Examples 1-12 18 I. Sample Preparation 19 3" x 3" samples used in the following decolorization examples were cut from a 2' 20 x 30' section of greige carpet constructed with nylon 6,6 fibers that was dyed to a deep 21 chocolate brown shade on commercial pilot-scale equipment using the following dye zz formulation at standard nylon 6,6 acid dyeing conditions:
24 Dle Dye Type is 0.2% C.I. Acid Blue 277 Anthraquinone 26 0.3%. C.I. Acid Red 361 Mono-azo 27 0.4% C. 1. Acid Orange 156 Di-azo zs 29 These dyes are conunonly used in the carpet industry as a wide variety of colors 3o can be obtained by varying the individual and total dye concentrations.
H; 27 i oa5(.t Y'v\01 I DOC) ~--'~ =~..
i 11. Decolori7ationlDYe Extraction Procedure 2 Twelve separate carpet fiber samples were placed in various decolorization test 3 formulabons, shown in Table l below, at a boil and at a pre-determined liquor to goods 4 ratio, generally 50:1. With a 3" x 3" sample weighing about 8g and at a 50:1 liquor to s goods ratio, the weight of test formulation was about 400g. Each test formulation 6 containing the sample was held at the boil for 5 minutes. The degree of decolorization 7 was qualitatively rated as A(excellent), B (good), C (fair), D(poor) or E
(bad) by visual a observation. The results are set forth in Table 1 below. A grade of C or above indicates an 9 amount of color removal desirable for re-use of the material.
io i i 111. Test Standardization 12 In order to provide a quantitative standard for decolorization testing, randorn test 13 samples from the above procedure were measured for residual color using a commercially 14 ava.ilable reflectometer, assigning the rellectartce or Delta E of the original brown carpet 1s to zero and relating the samples to this ite.m. Setting the untreated control carpet at a 16 Delta E of zero, an undyed or greige carpet exhibited a Delta E of 67, with the samples 17 being within this range. Visually, the following relationship of apparent process ie effectiveness to Delta E was established:
19 Delta E
20 RaTlge Grade Process 22 <40 E Bad 23 41-54 D Poor 24 55-57 C Fair 25 58-60 B Good 26 >60 A Excellent 11: 231045(4r9xoI 1.O0C) t 1 ~
+
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w p , , 00 C-, L3a V fY V
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i= U
--' o m Q O / ' Z /J
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U 22 m a. Q F. u] z ~ Z W x U 4c = x t ExaAOple 13 2 A room temperature decolorization formulation was prepared containing:
3 water 67%
4 benzyl alcohol 20%
aminomethyl propanol 10%
6 Ethfac 363 3%
7 This formulation is a single phase above 75 C. The pH of this solution was 11Ø
a A sample of dark brown carpet was treated at 100 C in the above-described solution for 9 five minutes. After cooling to room temperature, it was observed that the benzyl alcohol, containing most of the dye, made up a distinct bottom layer. The upper, aqueous layer I I did not clear up conipletely (i.e., some dye remained in the aqueous phase) even after 12 standing overnight.
13 Example 14 14 The carpet sample was removed from a two-phase solution prepared as in is Example 13, and sLtlfamic acid was added to the solution to reduce its pH
to 1.5. Good 16 dye separation was obtained from the aqueous phase to the alcohol phase.
The density of 17 the aqueous phase appeared to be higher than in Example 13; the alcohol phase was now 1s on top of the aqueous phase.
19 Example 15 The carpet sample was removed From a two-phase solution prepared as in 21 Example 13, and the solution was then adjusted in p.H to 7Ø The results wer,e the same 22 as in Example 14 except that the separation of the two phases occurred more slowly.
23 Also, it appeared that the aqueoLLs phase in this example did not increase in density as 24 much as the aqueous phase in Example 14.
Example 16 26 The carpet sample was removed from a two-phase solution prepared as in 27 Example 13, and NaCl was then added to the solution, since an increase of density in the ta aqueous phase in the previoLu example appeared to i,mpr.ove the separation of the aqueous 29 and alcohol phases and the rate of separation. The separation of the two phases was 10 excellent both in terms of the dye concentrating in the alcohol phase and in temis of the -I s-N:] iOaS(nY4Y01! DOC1 CA 02261303 1999-02-05 ~ =
I rate at wbich this separation occurred. The aqueous phase density was very high, Z allowing the benzyl alcohol to float on top of the aqueous phase, with all dye 3 conce.ntrated in this top layer. Thus, this procedure allows for easier dye and alcohol 4 recovery during processing.
s 6 The process and composition of the present invention are particularly usefitl. in the 7 recycling of thermoplastic materials. It has been unexpectedly discovered that ionically a dyeabl.e polymeric materials treated according to the present invention may be reutilized 9 in the same or different applications without exhibiting color pollution, degradation or io other detrimental ef'fect from the treatmen.t. Treated materials may be utilized in place of i I or blended with virgin thezrnoplastics in any known thermoplastics applications. A
12 preferred process of the present invention for forming an article therefore includes, after 13 the contacti.ng step, forming an article from the polymeric material. The article formi,ng ia step may include melting the treated material and may further include molding and )s solidifying the melted material or extruding the melted material to fotm fiber which may 16 be dyed. Techniques .for article forming are conventional and well known in the art.
17 While the compositions and methods of this invention have been described in Is terms of pre.fened embodime.nts, it will be apparent to those of skill in the art that 19 variations may be applied to the process described herein without departing from the 20 concept, spirit and scope of the invention. All such substitutions and modifications 21 apparent to those skilled in the art are deemed to be within the spirit, scope and concept 22 of the invention as it is set out in the following claims.
r1: 23 1o+c(.Yux9 u AoC)
24 Dle Dye Type is 0.2% C.I. Acid Blue 277 Anthraquinone 26 0.3%. C.I. Acid Red 361 Mono-azo 27 0.4% C. 1. Acid Orange 156 Di-azo zs 29 These dyes are conunonly used in the carpet industry as a wide variety of colors 3o can be obtained by varying the individual and total dye concentrations.
H; 27 i oa5(.t Y'v\01 I DOC) ~--'~ =~..
i 11. Decolori7ationlDYe Extraction Procedure 2 Twelve separate carpet fiber samples were placed in various decolorization test 3 formulabons, shown in Table l below, at a boil and at a pre-determined liquor to goods 4 ratio, generally 50:1. With a 3" x 3" sample weighing about 8g and at a 50:1 liquor to s goods ratio, the weight of test formulation was about 400g. Each test formulation 6 containing the sample was held at the boil for 5 minutes. The degree of decolorization 7 was qualitatively rated as A(excellent), B (good), C (fair), D(poor) or E
(bad) by visual a observation. The results are set forth in Table 1 below. A grade of C or above indicates an 9 amount of color removal desirable for re-use of the material.
io i i 111. Test Standardization 12 In order to provide a quantitative standard for decolorization testing, randorn test 13 samples from the above procedure were measured for residual color using a commercially 14 ava.ilable reflectometer, assigning the rellectartce or Delta E of the original brown carpet 1s to zero and relating the samples to this ite.m. Setting the untreated control carpet at a 16 Delta E of zero, an undyed or greige carpet exhibited a Delta E of 67, with the samples 17 being within this range. Visually, the following relationship of apparent process ie effectiveness to Delta E was established:
19 Delta E
20 RaTlge Grade Process 22 <40 E Bad 23 41-54 D Poor 24 55-57 C Fair 25 58-60 B Good 26 >60 A Excellent 11: 231045(4r9xoI 1.O0C) t 1 ~
+
p N uo v' f~
w p , , 00 C-, L3a V fY V
X
CL.1 n r ~
O O
i= U
--' o m Q O / ' Z /J
O e~ = ~ m Q N , , , ~O =y v, O o V p , o t M cn ~
G
'L+ .+
'y (I~
L1. y ! p ni O ~ C
- P p - U
C ~O
'F
r. ~ V cC
N !~ U h W SGG C~ a 6 O=.
o v td :~ C C~
r a.
s p o O F ~] ~ ai e~ WQ A O
F= o o C7 a Fz ci o I
s{ oo q d C a w p 0. a T c 0~ 211 >, w qj c ~i x y L y ~ p '' 3 E z J v~
O o o~i o C E~- ~ oxi '_o ~
m O ~.
U 22 m a. Q F. u] z ~ Z W x U 4c = x t ExaAOple 13 2 A room temperature decolorization formulation was prepared containing:
3 water 67%
4 benzyl alcohol 20%
aminomethyl propanol 10%
6 Ethfac 363 3%
7 This formulation is a single phase above 75 C. The pH of this solution was 11Ø
a A sample of dark brown carpet was treated at 100 C in the above-described solution for 9 five minutes. After cooling to room temperature, it was observed that the benzyl alcohol, containing most of the dye, made up a distinct bottom layer. The upper, aqueous layer I I did not clear up conipletely (i.e., some dye remained in the aqueous phase) even after 12 standing overnight.
13 Example 14 14 The carpet sample was removed from a two-phase solution prepared as in is Example 13, and sLtlfamic acid was added to the solution to reduce its pH
to 1.5. Good 16 dye separation was obtained from the aqueous phase to the alcohol phase.
The density of 17 the aqueous phase appeared to be higher than in Example 13; the alcohol phase was now 1s on top of the aqueous phase.
19 Example 15 The carpet sample was removed From a two-phase solution prepared as in 21 Example 13, and the solution was then adjusted in p.H to 7Ø The results wer,e the same 22 as in Example 14 except that the separation of the two phases occurred more slowly.
23 Also, it appeared that the aqueoLLs phase in this example did not increase in density as 24 much as the aqueous phase in Example 14.
Example 16 26 The carpet sample was removed from a two-phase solution prepared as in 27 Example 13, and NaCl was then added to the solution, since an increase of density in the ta aqueous phase in the previoLu example appeared to i,mpr.ove the separation of the aqueous 29 and alcohol phases and the rate of separation. The separation of the two phases was 10 excellent both in terms of the dye concentrating in the alcohol phase and in temis of the -I s-N:] iOaS(nY4Y01! DOC1 CA 02261303 1999-02-05 ~ =
I rate at wbich this separation occurred. The aqueous phase density was very high, Z allowing the benzyl alcohol to float on top of the aqueous phase, with all dye 3 conce.ntrated in this top layer. Thus, this procedure allows for easier dye and alcohol 4 recovery during processing.
s 6 The process and composition of the present invention are particularly usefitl. in the 7 recycling of thermoplastic materials. It has been unexpectedly discovered that ionically a dyeabl.e polymeric materials treated according to the present invention may be reutilized 9 in the same or different applications without exhibiting color pollution, degradation or io other detrimental ef'fect from the treatmen.t. Treated materials may be utilized in place of i I or blended with virgin thezrnoplastics in any known thermoplastics applications. A
12 preferred process of the present invention for forming an article therefore includes, after 13 the contacti.ng step, forming an article from the polymeric material. The article formi,ng ia step may include melting the treated material and may further include molding and )s solidifying the melted material or extruding the melted material to fotm fiber which may 16 be dyed. Techniques .for article forming are conventional and well known in the art.
17 While the compositions and methods of this invention have been described in Is terms of pre.fened embodime.nts, it will be apparent to those of skill in the art that 19 variations may be applied to the process described herein without departing from the 20 concept, spirit and scope of the invention. All such substitutions and modifications 21 apparent to those skilled in the art are deemed to be within the spirit, scope and concept 22 of the invention as it is set out in the following claims.
r1: 23 1o+c(.Yux9 u AoC)
Claims (39)
1. A process for removing colorants from an ionically dyeable polymeric material selected from the group consisting of polyamides and acrylics comprising:
contacting the polymeric material with a swelling agent under conditions sufficient to cause swelling and promote substantial diffusion of the colorants out of the polymeric material without substantial dissolution or degradation of the polymeric material.
contacting the polymeric material with a swelling agent under conditions sufficient to cause swelling and promote substantial diffusion of the colorants out of the polymeric material without substantial dissolution or degradation of the polymeric material.
2. A process for removing colorants from an ionically dyeable polymeric material selected from the group consisting of polyamides and acrylics comprising:
contacting the polymeric material with a swelling agent at a temperature of at least about a solution glass transition temperature of the polymeric material to promote substantial diffusion of the colorants out of the polymeric material without substantial dissolution or degradation of the polymeric material.
contacting the polymeric material with a swelling agent at a temperature of at least about a solution glass transition temperature of the polymeric material to promote substantial diffusion of the colorants out of the polymeric material without substantial dissolution or degradation of the polymeric material.
3. A process for extracting a dye from an ionically dyeable polymeric material selected from the group consisting of polyamides and acrylics comprising:
contacting the polymeric material with a swelling agent under conditions sufficient to promote substantial diffusion of the dye out of the polymeric material without substantial dissolution or degradation of the polymeric material.
contacting the polymeric material with a swelling agent under conditions sufficient to promote substantial diffusion of the dye out of the polymeric material without substantial dissolution or degradation of the polymeric material.
4. The process of any one of claims 1 to 3, wherein the swelling agent is part of an aqueous contacting composition, the contacting composition comprising water, swelling agent and a pH modifying agent and wherein said swelling agent is substantially miscible in said contacting composition during the contacting.
5. The process of any one of claims 1 to 4, wherein the swelling agent is a C1 to C10o alcohol.
6. The process of claim 5, wherein the swelling agent is present in an amount of at least about 10% by weight of the contacting composition.
7. The process of claim 4, wherein the pH modifying agent is selected from the group consisting of alkali metal hydroxides, alkali -metal oxides, trialkylalcohol amines.
alkyldiamines, dialkylamides and mixtures thereof.
alkyldiamines, dialkylamides and mixtures thereof.
8. The process of claim 4 or 7, wherein the contacting composition is substantially non-reactive with the colorants.
9. The process of claim 4, wherein the contacting composition is substantially non-reactive with the dye.
10. The process of claim 4, wherein the contacting composition further comprises a surfactant.
11. The process of any one of claims 1 and 3 to 10, wherein the contacting is conducted at a temperature of at least about a solution glass transition temperature of the polymeric material.
12. The process of any one of claims 1 to 11, wherein the contacting is conducted at a pH value of at least about 7.
13. The process of any one of claims 1 to 12, herein the contacting is conducted at a pH value of at least about 11.
14. The process of any one of claims 3 to 13, wherein the contacting is conducted under conditions sufficient to promote substantial diffusion of the dye out of the polymeric material without substantial degradation of the dye.
15. The process of claim 14 further comprising the step of recovering the dye.
16. A process for recycling a colored ionically dyeable polymeric material selected from the group consisting of polyamides and acrylics comprising:
providing an ionically dyeable polymeric material modified with at least one colorant.
contacting said polymeric material with at least one swelling agent under conditions sufficient to cause swelling and substantially remove the colorant from the polymeric material without substantial dissolution or degradation of the polymeric material thereby giving a substantially colorant free polymeric material; and forming an article from the substantially colorant free polymeric material.
providing an ionically dyeable polymeric material modified with at least one colorant.
contacting said polymeric material with at least one swelling agent under conditions sufficient to cause swelling and substantially remove the colorant from the polymeric material without substantial dissolution or degradation of the polymeric material thereby giving a substantially colorant free polymeric material; and forming an article from the substantially colorant free polymeric material.
17. The process of claim 16, wherein the contacting is carried out at a temperature of at least about a glass transition temperature of the polymeric material.
18. The process of claim 17, wherein the contacting is carried out at a pH
value of at least about 7.
value of at least about 7.
19. The process of claim 17, wherein the contacting is carried out at a pH
value of at least about 11.
value of at least about 11.
20. The process of claim 18 further comprising washing the substantially colorant free polymeric material with a washing agent so as to remove residual colorant and swelling agent.
21. The process of claim 20, wherein the article formed from the substantially colorant free polymeric material is a fiber.
22. The process of claim 20, wherein the colorant is a dye and the contacting and washing are carried out under conditions to promote substantial diffusion of the dye out of the polymeric material without substantial degradation of the dye.
23. The process of claim 22 further comprising separating the dye from the swelling agent, recycling the swelling agent back into the process and reusing the dye to color ionically dyeable polymeric materials.
24. A process for recycling colored polyamide or acrylic polymeric material, comprising contacting solid colored polymeric material with an aqueous C1-C10 alcohol solution at a temperature effective to cause swelling of the polymeric material without substantial dissolution or degradation of the polymeric material, whereby colorant is removed from the polymeric material, producing a decolored polymeric material.
25. The process of claim 24, where the polymeric material is polxyamide.
26. The process of claim 24, where the solid colored polymeric material is an ionically dyed polyamide
27. The process of claim 24, where the colored polymeric material is contacted with the aqueous C1-C10 alcohol solution at a temperature between about 90-102°C.
28. The process of claim 24, where the colored polymeric material is contacted with the aqueous C1-C10 alcohol solution at a temperature of about 97°C or higher
29. The process of claim 24, where the aqueous alcohol solution comprises at least one alcohol selected from the group consisting of benzylalcohol, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol and cyclohexanol.
30. The process of claim 24, where the aqueous alcohol solution further comprises a surfactant at a concentration effective to cause the aqueous alcohol solution to be a single phase at the temperature at which that solution is contacted with the colored polymeric material, and to separate into two phases at a temperature between about 20-7-5°C.
31. The process of claim 24 further comprising the step of recovering said colorant from the aqueous alcohol solution.
32. The process of claim 24 further comprising the step of recovering the decolored polymeric material.
33. The process of claim 24 further comprising the step of washing the decolored polymeric material with a polar liquid.
34. The process of claim 33, where the polar liquid is selected from the group consisting of water, C1-C4 aliphatic alcohols, C3-C6 ketones, and mixtures thereof.
35. The process of claim 33, where the polar liquid is a mixture of acetone and water.
36. The process of claim 24, where the aqueous alcohol solution comprises at least about 50% by weight water.
37. A process for recycling colored polyamide material, comprising:
contacting solid colored polyamide material with an aqueous solution that comprises:
(a) at least about 50% by weight water, (b) at least one C1-C10 alcohol, (c) a surfactant in an amount effective to cause the solution to form a single phase at a temperature between about 90-102°C, and to form two phases at a temperature between about 20-75°C, and (d) a pH modifying agent effective to adjust the pH of the solution to at least about 7; thereby causing swelling of the polyamide material and removal of colorant from the polyamide material, producing a decolored polyamide material; and cooling the aqueous alcohol solution to a temperature between about 20-75°C, whereby the solution separates into an aqueous phase and an alcohol phase, more than 50% by weight of the colorant removed from the polyamide being contained in the alcohol phase.
contacting solid colored polyamide material with an aqueous solution that comprises:
(a) at least about 50% by weight water, (b) at least one C1-C10 alcohol, (c) a surfactant in an amount effective to cause the solution to form a single phase at a temperature between about 90-102°C, and to form two phases at a temperature between about 20-75°C, and (d) a pH modifying agent effective to adjust the pH of the solution to at least about 7; thereby causing swelling of the polyamide material and removal of colorant from the polyamide material, producing a decolored polyamide material; and cooling the aqueous alcohol solution to a temperature between about 20-75°C, whereby the solution separates into an aqueous phase and an alcohol phase, more than 50% by weight of the colorant removed from the polyamide being contained in the alcohol phase.
38. The process of claim 37, where the pH modifying agent is effective to adjust the pH of the solution to at least about 11.
39. The process of claim 37, where, after cooling, more than 80% by weight of the colorant removed from the polyamide is contained in the alcohol phase.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
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US09/019,911 US6083283A (en) | 1996-10-24 | 1998-02-06 | Method for removing color from ionically dyeable polymeric materials |
US09/019,911 | 1998-02-06 |
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CA2261303C true CA2261303C (en) | 2008-10-07 |
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