BIOCOMPATIBLE AND BIODEGRADABLE NATURAL DISPERSE DYES FOR DYEING POLYESTER FABRICS
20180258287 ยท 2018-09-13
Inventors
Cpc classification
International classification
Abstract
The present invention is directed to a biocompatible and biodegradable natural disperse dye for dyeing polyester fabrics which is dispersed in water and derived from green plants. The disperse dye contains as the active dye compound an acid bewchlorophyllin derivative such as acid form Mg-chlorophyllin or acid form Cu-chlorophyllin. The disperse dye of the present invention can be used for the dyeing of polyester fabrics by traditional methods in concentrations ranging from 0.01% to 20% on weight of fibers (OWF), thus providing a dyed fabric with good color strength and good fastness to light, washing and rubbing, under conditions of dye exhaustion of greater than 90%.
Claims
1. A method of preparing a chlorophyll-based disperse dye, comprising: obtaining green plant biomass having a chlorophyll content of >1% relative to total dry matter; extracting soluble components of said green plant mass, thereby producing a pigment extract; reacting said pigment extract with a base, thereby saponifying chlorophyll within said pigment extract to produce a basified pigment extract comprising a water-soluble chlorophyllin salt; acidifying said basified pigment extract, thereby producing a solid material comprising water-insoluble protonated M-chlorophyllin, where M is a divalent metal ion; and, dispersing said solid material, thereby yielding a disperse dye comprising water-insoluble M-chlorophyllin as an active dyeing compound and multi-component material derived from said green plant biomass.
2. The method according to claim 1, wherein said step of obtaining green plant biomass comprises obtaining green plant mass characterized by at least one characteristic selected from the group consisting of: protein content of >25% relative to total dry matter; fat content of >4% relative to total dry matter; and fiber content of <9% relative to total dry matter.
3. The method according to claim 1, wherein said step of obtaining green plant biomass comprises obtaining green plant biomass from duckweed.
4. The method according to claim 1, wherein said step of extracting comprises extracting with a solvent selected from the group consisting of water, organic solvents that are miscible with water, and mixtures thereof.
5. The method according to claim 4, wherein said step of extracting comprises extracting with water.
6. The method according to claim 1, wherein said step of acidifying comprises at least one step selected from the group consisting of: acidifying to a pH of between 3 and 7; and, acidifying in the presence of 0.1-5% of a dispersing agent, under conditions selected from the group consisting of (a) mixing at not less than 1000 RPM and (b) acidifying in a homogenizer, until said dispersion comprises particles having an average size of not more than 10 m.
7. The method according to claim 1, comprising crushing particles of said solid material to produce an average size of not more than 1 m.
8. The method according to claim 1, wherein said step of dispersing comprises: filtering said dispersion by vacuum filtration, thereby producing a wet solid; and, adding water to said wet solid, thereby producing an aqueous dispersion.
9. The method according to claim 1, comprising a step of substituting Mg.sup.2+ with a different divalent metal cation.
10. The method according to claim 9, wherein said step of substituting Mg.sup.2+ with a different divalent metal cation comprises substituting Mg.sup.2+ with Cu.sup.2+ subsequent to said step of saponifying by treatment with an aqueous solution of a Cu(II) salt.
11. The method according to claim 1, additionally comprising adding water after said step of saponifying.
12. A chlorophyll-based disperse dye, wherein said dye comprises: water-insoluble protonated M-chlorophyllin, where M represents a divalent metal cation, as an active dyeing agent; and, multi-component material obtained from extraction of green plant biomass having a chlorophyll content of >1% relative to total dry matter.
13. The disperse dye according to claim 12, wherein said multi-component material is obtained from extraction of green plant biomass characterized by at least one characteristic selected from the group consisting of: protein content of >25% relative to total dry matter; fat content of >4% relative to total dry matter; and fiber content of <9% relative to total dry matter.
14. The disperse dye according to claim 12, wherein said multi-component material is obtained from extraction of duckweed.
15. The disperse dye according to claim 12, wherein said water-insoluble protonated M-chlorophyllin and said multi-component material are products of a process that comprises extracting green plant biomass to obtain an extract that comprises chlorophyll or a derivative thereof and said multi-component material.
16. The disperse dye according to claim 12, wherein M is selected from the group consisting of Mg.sup.2+, Cu.sup.2+, Fe.sup.2+, Zn.sup.2+, and Cd.sup.2+.
17. The disperse dye according to claim 16, wherein M is Cu.sup.2+.
18. The disperse dye according to claim 12, wherein said dye comprises an aqueous dispersion of particles comprising said active dyeing compound.
19. The disperse dye according to claim 18, wherein said aqueous dispersion is characterized by at least one characteristic selected from the group consisting of: said aqueous dispersion has a pH of between 4 and 6; said aqueous dispersion comprises particles having an average size of not more than 1 m; said aqueous dispersion comprises 4-40% solids by weight; said aqueous dispersion has a viscosity of between 0.5 and 5 Pa s; and, said aqueous dispersion is characterized by a filtering time of greater than 60 s as determined by AATCC test method 146-2001.
20. The chlorophyll-based disperse dye according to claim 12, wherein said disperse dye is produced by a method comprising: obtaining green plant biomass having a chlorophyll content of >1% relative to total dry matter; extracting soluble components of said green plant mass, thereby producing a pigment extract; reacting said pigment extract with a base, thereby saponifying chlorophyll within said pigment extract to produce a basified pigment extract comprising a water-soluble chlorophyllin salt; acidifying said basified pigment extract, thereby producing a solid material comprising water-insoluble protonated M-chlorophyllin, where M is a divalent metal ion; and, dispersing said solid material, thereby yielding a disperse dye comprising water-insoluble M-chlorophyllin as an active dyeing compound and multi-component material derived from said green plant biomass.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0053] The patent application file contains at least one drawing executed in color. Copies of this patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.
[0054] The invention will now be described with reference to the drawings, wherein:
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DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0066] In the following description, various aspects of the invention will be described. For the purposes of explanation, specific details are set forth in order to provide a thorough understanding of the invention. It will be apparent to one skilled in the art that there are other embodiments of the invention that differ in details without affecting the essential nature thereof. Therefore the invention is not limited by that which is illustrated in the figure and described in the specification, but only as indicated in the accompanying claims, with the proper scope determined only by the broadest interpretation of said claims.
[0067] As used herein, the term multi-component material refers to a material comprising a mixture of high molecular weight and low molecular weight substances. Note that by this definition, a multi-component material may comprise not only one or more well-defined macromolecular substances mixed with one or more pure molecular substances, but it may comprise substances such as plant parts or even whole plants.
[0068] As used herein, the term duckweed is used generically to refer to aquatic plants of the subfamily Lemnoideae.
[0069] Unless specifically stated otherwise, concentrations of solutions and suspensions are given as w/v percentages.
[0070] The disperse dye of the present invention contains as the active dyeing compound a water-insoluble protonated M-chlorophyllin, where M represents a divalent metal ion. In preferred embodiments of the invention, M=Mg.sup.2+ or Cu.sup.2+, but any suitable divalent metal (e.g. Fe.sup.2+, Zn.sup.2+, Cd.sup.2+, etc.) may be used. Unlike chlorophyllin-based dyes known in the art, the dye of the present invention is suitable for dyeing of hydrophobic fibers such as polyester. In preferred embodiments of the invention, the dye is a multi-component material that includes plant material in addition to the active dyestuff. Without wishing to be bound by theory, it appears that the presence of the multi-component material produces a superior dye to those prepared from commercially available chlorophyllin salts. As shown in the following description and examples, the composition of the plant extract that is the basis of the dye disclosed herein appears to be conducive to the formation of a stable, uniform dispersion when acidified. The composition coats hydrophobic fibers such as polyester uniformly to yield a stable, level, bright green color. Fabrics dyed using the plant-based green dye of the present invention show significantly better colorfastness when laundered or exposed to light than do fabrics dyed using copper chlorophyllin-based dyes known in the prior art.
[0071] In preferred embodiments of the invention, the dye is in the form of water-insoluble particles made of multi-component material that includes the water-insoluble protonated M-chlorophyllin. In some preferred embodiments of the invention, the dye comprises an aqueous dispersion of particles of the active dyeing compound. In preferred embodiments, the average particle size is not more than 10 m. In more preferred embodiments, the average particle size is not more than 5 m. In yet more preferred embodiments, the average particle size is not more than 2 m. In the most preferred embodiments, the average particle size is not more than 1 m. In preferred embodiments of the invention, the dispersion comprises between 2 and 40% solids by weight. In preferred embodiments of the invention, the dispersion has a viscosity of between 0.5 and 5 Pa s and a filtering time of greater than 60 s as determined by AATCC test method 146-2001. Methods of preparation of a dye having these physical properties are given in detail below.
[0072] It is also within the scope of the invention to disclose a method of preparation of the protonated M-chlorophyllin disperse dye. In one exemplary embodiment of the present invention, the disperse dye is produced by saponification of chlorophyll, which hydrolyzes the ester moities bound to the chlorin ring system, releasing phytol and methanol and yielding a water-soluble Mg-chlorophyllin salt. The water-soluble chlorophyllin salt is then acidified, yielding a water-insoluble protonated Mg-chlorophyllin, which precipitates from the aqueous medium in the form of a solid material with a low tendency to agglomerate.
[0073] A non-limiting illustration of the above reaction sequence is shown in Scheme 3 for an embodiment in which the dye is based on chlorophyll a.
##STR00002## ##STR00003##
[0074] In some embodiments of the invention, the Mg atom is replaced with an atom of a different metal. Non-limiting examples include Cu, Zn, Fe, and Cd. In preferred embodiments of the invention, the Mg atom is replaced by a Cu atom. A non-limiting example of a method by which the Mg atom (again, for an embodiment in which the dye is based on chlorophyll a) is presented in Scheme 4.
##STR00004## ##STR00005##
[0075] Green plant biomass serves as the source of the chlorophyll that is modified to produce the disperse dye of the present invention. It is therefore within the scope of the invention to disclose a method for producing the disperse dye from green plant biomass.
[0076] Any source of green plant biomass having a chlorophyll content of greater than 1% relative to the total dry matter may be used. The biomass may be either fresh or dried. A preferred source of plant biomass is duckweed. An especially preferred source of plant biomass is duckweed of genus Wolffia, due to its high chlorophyll content (4 -7% by weight on a dry weight basis). Duckweed plants of genus Wolffia have the additional properties of having high fat content (ca. 5%), low fiber (ca. 9%), ash (ca. 15%) and very high protein (>25%). For comparison, alfalfa, which is a typical source for commercially available chlorophyllin derivatives, comprises 15% protein, 25% fiber and 0.7% fat.
[0077] While fresh plant biomass can be used, in preferred embodiments, the plant biomass is dried prior to extraction of the pigment. In preferred embodiments, the biomass is dried in the dark; any process or equipment known in the art can be used. The temperature should not exceed 50 C. during the drying process. In preferred embodiments, the drying takes place at a temperature not exceeding 45 C. In the most preferred embodiments, the drying takes place at a temperature not exceeding 40 C. Drying at low temperatures is preferred in order to prevent or limit thermal degradation of the plant pigments to be extracted. In some embodiments, the drying is performed until the moisture content of the biomass is between 10 and 15% by weight. In other embodiments, the drying is performed until the moisture content of the biomass is between 5 and 10% by weight. In yet other embodiments, the drying is performed until the moisture content of the biomass is between 2 and 4% by weight.
[0078] In preferred embodiments of the invention, the dried plant matter is ground, in order to mechanically disrupt the plant cells and increase the efficiency of the extraction of the pigment. The grinding may be performed using any method or apparatus known in the art. In preferred embodiments, a ball mill is used, preferably one that is equipped with a cooling system such that the temperature during the grinding does not exceed 30 C. In preferred embodiments of the invention, the plant matter is ground until the maximum size of the particles is not more than 200 m. In more preferred embodiments, the plant matter is ground until the maximum size of the particles is not more than 150 m. In the most preferred embodiments, the plant matter is ground until the maximum size of the particles is not more than 100 m.
[0079] Extraction of pigment from the plant matter can be performed by any process known in the art. In preferred embodiments, the solvent is water, an organic solvent that is miscible with water, or mixtures thereof. Non-limiting examples of suitable organic solvents include alcohols, ketones, esters, ethers, and other polar aprotic solvents such as dimethyl formamide (DMF) or dimethyl sulfoxide (DMSO). In embodiments in which organic solvent is used, the solvent is preferably ethanol. In the most preferred embodiments of the invention, the pigment is extracted with water. In some embodiments of the invention, the ratio of biomass to solvent is 1:20 (w/v). In preferred embodiments of the invention, the ratio of biomass to solvent is 1:25 (w/v). In more preferred embodiments of the invention, the ratio of biomass to solvent is 1:30 (w/v).
[0080] In preferred embodiments of the invention, a batch extraction procedure is used. In more preferred embodiments of the invention, Soxhlet extraction under vacuum is performed. In some embodiments of the invention, the extraction is performed between 50 and 70 C. In other embodiments of the invention, the extraction is performed between 40 and 60 C. In yet other embodiments of the invention, the extraction is performed between 30 and 50 C.
[0081] In general, the extraction is performed until the concentration of pigment in the solvent leaving the extractor reaches a predetermined value. In preferred embodiments of the invention, the reflux flow within the extractor is periodically microsampled and analyzed for pigment concentration increase. The extraction is stopped when the concentration increase of pigment is less than 0.002 g/L in a 15 minute period, as determined spectrophotometrically by ESS method 150.1. In preferred embodiments, the extract has a concentration of 0.2 to 2% by weight of plant biomass. In typical embodiments of the invention, the concentration of pigment in the extract, expressed as total chlorophyll (a+b), is between 1 and 3% relative to the total dry weight of the extracted plant matter (i.e. the extract contains between 0.002 and 0.06% pigment (w/v)). In other embodiments of the invention, the concentration of pigment in the extract, expressed as total chlorophyll (a+b), is between 1.5 and 3.5% relative to the total dry weight of the extracted plant matter (i.e. the extract contains between 0.003 and 0.07% pigment (w/v)). In yet other embodiments of the invention, the concentration of pigment in the extract, expressed as total chlorophyll (a+b), is between 2 and 4% relative to the total dry weight of the extracted plant matter (i.e. the extract contains between 0.004 and 0.08% pigment (w/v)). Note that while the endpoint of the extraction is generally determined from the concentration of the pigment, the extract will include multi-component material in addition to the pigment.
[0082] In preferred embodiments of the invention, the extract is concentrated by vacuum distillation, more preferably at a temperature not exceeding 40 C., until about half of the solvent is removed.
[0083] The extract (in preferred embodiments, the concentrated extract) is then saponified. Any method known in the art may be used. In preferred embodiments of the invention, an aqueous solution of LiOH, NaOH, or KOH is used to perform the saponification. In more preferred embodiments of the invention, a 10% solution (w/v) of base is used. In more preferred embodiments of the invention, the base used is KOH. In typical embodiments of the invention, the amount of base added to the extract in order to perform the saponification is 50-90% w/w relative to the amount of plant matter in the extract (dry basis). In preferred embodiments, the amount of base added is 55-85% w/w relative to the amount of plant matter in the extract (dry basis). In yet more preferred embodiments, the amount of base added is 60-80% w/w relative to the amount of plant matter in the extract (dry basis).
[0084] The saponification is typically performed at a temperature between 30 and 70 C. In preferred embodiments, it is performed at a temperature between 35 and 65 C. In more preferred embodiments, it is performed at a temperature between 40 and 60 C. In typical embodiments, the saponification is run for 20-90 minutes. In preferred embodiments, it is run for 30-75 minutes. In more preferred embodiments, it is run for 40-60 minutes. In preferred embodiments, the saponification is performed under mixing (typically at about 60 rpm) and under vacuum (typically 30-40 kPa). Following the saponification, the remaining solvent is removed under vacuum, leaving saponified material. Water is then added to the material remaining after the removal of the solvent. In some embodiments of the invention, sufficient water is added such that the concentration of saponified material is between 12 and 16% w/w. In other embodiments of the invention, sufficient water is added such that the concentration of saponified material is between 13 and 17% w/w. In yet other embodiments of the invention, sufficient water is added such that the concentration of saponified material is between 14 and 18% w/w. The amount of residual solvent in the resulting solution is generally less than 2%.
[0085] The saponified material is then acidified. In typical embodiments of the invention, acid is added until the pH is between 3 and 7. In preferred embodiments of the invention, acid is added until the pH is between 3.5 and 6.5. In more preferred embodiments of the invention, acid is added until the pH is between 4 and 6. In some preferred embodiments of the invention, the acidification is performed by addition of HCl or acetic acid. In more preferred embodiments of the invention, the acidification is performed by addition of 10% (w/v) acetic acid.
[0086] As shown in Scheme 3 above, acidification of the saponification product produces water-insoluble protonated M-chlorophyllin. The acidification normally produces the protonated M-chlorophyllin in the form of a dispersion. This dispersion is treated by filtration under vacuum. In some embodiments of the invention, the filtrate has a solid content of 0.05-0.8% by weight. In some preferred embodiments of the invention, the filtrate has a solid content of 0.05-0.5% by weight. In some more preferred embodiments of the invention, the filtrate has a solid content of 0.05-0.2% by weight.
[0087] In some embodiments of the invention, is dried to powder. In other embodiments of the invention, the wet filtrate is mixed with a predetermined quantity of water. In some embodiments of the invention in which the wet filtrate is mixed with water, the ratio of wet solid to added water is 1:4 by weight. In preferred embodiments of the invention, the ratio of wet solid to added water is 1:3 by weight. In more preferred embodiments of the invention, the ratio of wet solid to added water is 1:2 by weight. In some embodiments, the resulting dispersion will thus comprise between 2 and 40% active dye material. In other embodiments, the resulting dispersion will comprise between 3 and 30% active dye material. In yet other embodiments, the resulting dispersion will comprise between 4 and 20% active dye material.
[0088] In preferred embodiments, the dispersion is treated to reduce the average particle size. The comminution may be performed by any means known in the art. Preferred methods include crushing or grinding in a ball mill or high speed homogenizer. In typical embodiments of the invention, the comminution yields an average particle size of not more than 10 m. In preferred embodiments of the invention, the comminution is performed until the average particle size is not more than 5 m. In more preferred embodiments of the invention, the comminution is performed until the average particle size is not more than 2 m. In the most preferred embodiments of the invention, the comminution is performed until the average particle size is not more than 1 m.
[0089] The viscosity of the resulting natural disperse dye is typically between 0.5 and 5 Pa s. In preferred embodiments, the viscosity is between 0.75 and 3 Pa s. In more preferred embodiments, the viscosity is between 1 and 2 Pa s. The dispersibility of the disperse dye, as measured by filtering time, is typically greater than 60 s. In preferred embodiments, it is greater than 80 s. In more preferred embodiments, it is greater than 100 s. In practice, if a particular batch of the dye is not within the above limits for viscosity and dispersibility, the batch is rejected.
[0090] As shown in Scheme 4 above, in some embodiments of the invention, the Mg.sup.2+ present in naturally-occurring chlorophyllin is replaced by a different divalent metal cation. non-limiting examples of appropriate divalent metal ions include Fe.sup.2+, Cu.sup.2+, Zn.sup.2+, and Cd.sup.2+. In a preferred embodiment of the invention, the active dye material contains Cu.sup.2+, which provides a bright green color. In preferred embodiments of the invention, the substitution of Mg.sup.2+ with another divalent metal cation is performed after saponification but before acidification of the saponified material. In general, the substitution is performed by treatment of the saponified material by reaction with an aqueous solution of a salt of the cation that is substituting the Mg.sup.2+.
[0091] As a non-limiting example of how the substitution is performed, one embodiment of a method for substituting the Mg.sup.2+ with Cu.sup.2+ is given here. The aqueous solution of saponified plant extract is treated with an aqueous solution of a copper(II) salt. In preferred embodiments of the invention, the copper(II) salt is selected from the group consisting of copper(II) acetate, copper(II) sulfate, copper(II) nitrate, and copper(II) chloride. In the most preferred embodiments of the invention, CuSO.sub.4.5H.sub.2O is used.
[0092] In typical embodiments of the invention, sufficient solution of the copper(II) salt is added to the solution containing the saponification product to provide 2-3% by weight of the copper(II) salt (dry basis of salt relative to the extract) is used. In other embodiments of the invention, 2.5-3.5% by weight of the copper(II) salt (dry basis of salt relative to the extract) is provided. In yet other embodiments of the invention, 3-4% by weight of the copper(II) salt (dry basis of salt relative to the extract) is provided.
[0093] In some embodiments of the invention, the reaction between the copper(II) salt and the saponification product takes place at a temperature between 35 and 45 C. In other embodiments of the invention, the reaction takes place at a temperature between 40 and 55 C. In yet other embodiments of the invention, the reaction takes place at a temperature between 45 and 65 C. The reaction is typically run for 20 to 120 minutes. In preferred embodiments of the invention, the reaction is run for 30 to 100 minutes. In more preferred embodiments of the invention, the reaction is run for 40 to 80 minutes. After the reaction is run, steps of acidification and subsequent treatment are performed as described above.
[0094] Typically, in order to determine whether the reaction is complete, the amount of Cu(II) remaining in solution is monitored. When the reaction has reached equilibrium (typically after about 30 min), it is deemed to have reached its end point.
[0095] As discussed above, the substitution of Mg.sup.2+ with a divalent cation other than Cu.sup.2+ is contemplated by the inventors as being within the scope of the invention. One of ordinary skill in the art will understand that in order to replace the Mg.sup.2+ with a cation other than Cu.sup.2+, an analogous method using a salt of a different method is performed.
EXAMPLES
[0096] The following non-limiting examples are provided to illustrate to a person having ordinary skill in the art how to make and use the invention herein disclosed.
Example 1
[0097] A non-limiting example of the process for obtaining a natural disperse dye, in which the active dyeing compound is protonated Mg-chlorophyllin, is now presented.
[0098] Fresh green plant biomass of Wolffia arrhiza, which had the chemical composition presented in Table 1, was obtained. Fiber is included within the total carbohydrate.
TABLE-US-00002 TABLE 1 Compound UM Values Water % 94.73 Protein % 1.97 Total Fat % 0.24 Total Carbohydrate % 2.09 Ash % 0.71 Sodium mg/100 g 29.53 Potassium mg/100 g 161.38 Magnesium mg/100 g 21.32 Copper mg/100 g 0.49
[0099] 2 kg fresh harvested duckweed was dried at 40 C. for 24 hours in a EZIDRI ULTRA FD 1000 (Food Dehydrators, Israel) drier, which was kept in the dark. 109.2 g of dried biomass with a moisture content of 3.67 percent was obtained.
[0100] The dried biomass was chopped with a disc mill (WEGA coffee grinder, Italy) to yield a powder with a maximum particle size of 150 microns.
[0101] 90 g of the dry biomass powder then was extracted with ethanol under vacuum in the dark in a battery of 6 Soxhlet extractors, each of which had a 100 ml capacity. Each thimble was loaded with 15 g powder, 250 ml of ethanol (99%) was introduced into a 500 ml extraction flask. The extraction was run at a temperature of 50 C. for 3 hours. 1500 ml of extract of 1.05% w/v concentration (total solid 15.75 g) was obtained.
[0102] The chlorophyll (a+b) content of the crude extract was characterized by the method of Lichtenthaler (Lichtenthaler, H. K. Method Enzymol. 1987, 148, 350-382; Ritchie, R. J. Photosynth. Res. 2006, 89, 27-41), using a Cary 60 UV-VIS spectrophotometer, and a value of 2.92% green pigment by dry mass of extract was obtained. The UV-VIS spectrum of the extract is presented in
[0103] 750 ml of ethanol were removed from the extract by vacuum distillation at a temperature of 50 C. using a Buchi R-134 rotary evaporator. A solution of 11.81 g of KOH in 173 ml distilled water was then added. Removal of ethanol continued in for an additional 60 minutes at 50 C. and a pressure of 330 mbar. A uniform solution of green intense color with a concentration of 16.01% was obtained.
[0104] The saponified extract was then acidified by addition of 12 ml of a 10% (w/v) acetic acid solution until a pH of 5.5 was reached. The resulting dispersion, which did not show any aggregation, was filtered under vacuum. 167.3 g of liquid and 45.26 g wet filtrate were obtained. The wet filtrate was diluted with 54.74 ml of distilled water resulting in 100 g of concentrated dispersion. This dispersion was subjected to additional dispersal using an Ultra Turax homogenizer at 20,000 rpm for 15 seconds.
[0105] Finally, 96 g natural disperse dye was obtained (some of the dye was lost on transfer to and removal from the homogenizer), comprising protonated Mg-chlorophyllin as the active dyeing ingredient. The dye had a pH of 5.73, a viscosity of 1.852 Pa s (as measured by using a MYR VR-3000 viscometer) and dispersability of 89 sec as determined by AATCC test method 146-2001.
Example 2
[0106] The thermal stability of a disperse dye containing protonated Mg-chlorophyllin as the active dyeing material was determined under thermal conditions near those that are used for dyeing of polyester fabrics.
[0107] 10 g of an aqueous Mg-chlorophyllin dispersion was added to a 50 ml glass Erlenmeyer flask fitted with a stopper, sealing system with spring, and magnetic stir bar. The flasks were immersed for 60 min in a preheated water bath placed on a heating plate equipped with a magnetic stirrer. The dispersion was cooled to room temperature and the disperse phase separated from the dispersion medium by filtration under vacuum. The wet filtrate was then re-dissolved in ethanol, and the resulting solution resulted was analyzed by UV-VIS spectroscopy. The experiment was performed four times, at 70 C., 80 C., 90 C., and 100 C., respectively. The experimental results are shown in
[0108] Reference is now made to
[0109] Reference is now made to
Example 3
[0110] A non-limiting method for obtaining a natural disperse dye, in which the active dyeing compound is protonated Cu-chlorophyllin, is presented.
[0111] An aqueous solution saponified plant extract was obtained using the same source of plant biomass and the same processing method as were given in Example 1 above.
[0112] 4 ml of a 20% (w/v) solution of CuSO.sub.4.5H2O was added directly into the flask of rotary evaporator containing the solution of saponified extract. The solutions were mixed at 60 rpm for 60 min at 56 C. under a pressure of 850 mbar. Reference is now made to
[0113] The resulting solution of is processed as described in example 1 above except that 10 ml of a fatty acid ethoxylate dispersing agent (SETAVIN PE) was added.
[0114] 97.8 g of a natural disperse dye containing protonated Cu-chlorophyllin as the active dyeing material was obtained. The dye had a pH of 5.68, a viscosity of 3.144 Pa s, and dispersability of 106 sec as determined by AATCC test method 146-2001.
[0115] Thermal stability tests identical to those described in Example 2 above were performed on the Cu-chlorophyllin based dye. Reference is now made to
Example 4
[0116] A non-limiting example of the use on polyester of a natural disperse dye with protonated Cu-chlorophyllin as the active dyeing compound is presented. The dye was prepared as described in Example 2 above.
[0117] 500 ml vessels of an AHIBA DATACOLOR IRTM beaker dyeing machine were charged with 10 g of polyester fabric and 400 ml of a dispersion of the natural disperse dye (1:40 liquor ratio) containing 1, 0.5, 0.25, and 0.125 g/l of disperse dye, corresponding to 4%, 2%, 0.5% and 0.25% dye on weight of fabric (OWF), respectively. The dye vessels were heated to 130 C. The fabrics were then dyed at 130 C. for 1 hour, cooled to 60 C. over the course of 30 minutes, removed from the dye vessels, rinsed with water at 60 C. for 15 minutes, and dried at 105 C. Reference is now made to
[0118] The dyed fabrics were laundered at 60 C. using the AATCC standard procedure for home laundry. Nearly full exhaustion was obtained (>90% exhaustion as measured by gravimetry of applied versus unbound pigment concentrations). The dyed cloth had a khaki/green shade with a clear gradation of color depth according to dyebath concentration from a light shades for 0.25% and 0.5% OWF to medium shades for 2% and 4% OWF (CIE LCH parameters=(L: 97.1, C: 12.2, H: 105.8) ; (L: 90.3, C: 45.8, H: 101.3) ; (L: 83.7, C: 74.3, H: 97.6) ; (L: 69.3, C: 68.7, H: 96.7) , respectively.). The fabrics were durable to laundry with no significant color change (dE<1).
Example 5
[0119] As a demonstration of advantages of the instant invention over the prior art, a comparison was made of the properties of fabric dyed by using the invention disclosed herein with fabric dyed by using a copper chlorophyllin dye prepared according to procedures known in the art.
[0120] A solution comprising copper chlorophyllin prepared by extraction of chlorophyll from Wolffia was prepared according to the procedures described above. The solution contained 4.3% by weight green matter. 24 ml of the solution and 10 ml of a fatty acid ethoxylate dispersant (SETAVIN PE, obtained from Zschimmer & Schwarz) were added to 1 liter of soft water (5 ppm) under stirring at 500 rpm. 2 ml of glacial acetic acid was added dropwise in order to obtain a 1 g/L solution of the coppered extract at pH 4. After stirring for 30 minutes, a dispersion of water-insoluble green pigment was obtained. The turbidity of the suspension was measured by using a HANNA HI 88703 turbidity meter. The turbidity of the initial solution was 10 NTU, and the final turbidity of the suspension after acidification was 200 NTU.
[0121] A second dye was prepared from commercially available Cu-chlorophyllin. The Cu-chlorophyllin was obtained as a powder containing 89.3% green solids (Sigma-Aldrich). The sources of chlorophyll in the commercially available Cu-chlorophyllin were nettle, alfalfa, and grass. 4.7 g of the powder was dissolved in 100 ml of soft water to obtain a solution containing 4.3% green matter. The dye was then prepared as above for the Wolffia extract, i.e. the two dye dispersions had identical solids content. The turbidity of the dye prepared from the commercially obtained Cu-chlorophyllin was 210 NTU.
[0122] Polyester knit fabric (215 g/m.sup.2) was then dyed according to the following procedure. For each dye, four suspensions, containing 0.125, 0.25, 0.5, and 1 g/L dye were prepared. For each dye suspension, a 500 ml vessel of a MATHIS dyeing machine was charged with 10 g of fabric and 400 ml of a dye solution, i.e. the four dye suspensions corresponded to concentrations of 0.25%, 0.5%, 2%, and 4% on weight of fabric (OWF). The fabrics were dyed at 130 C. for 1 hour, rinsed, and soaped by using 2 ml/L TISSOCYL DLF for 30 minutes at 60 C. The fabric samples were rinsed and then dried at 105 C. The procedure is summarized in
[0123] The results of the dyeing are illustrated in
[0124] The dyestuff of the instant invention also showed superior exhaustion and fixation as is demonstrated by the difference in the color depth of the rinse water, which is shown in
[0125] Without wishing to be bound by theory, it appears that the multi-component material that comprises the dye of the invention herein disclosed enables the active dye component to bind more strongly and more evenly to the fabric compared to a dye that is made from commercially available Cu-chlorophyllin but that lacks the multi-component material derived from duckweed.
Example 6
[0126] The ability of the two dyes described in the previous example to withstand laundering was tested. The fabrics were laundered at 60 C. using AATCC standard laundry conditions (AATCC Monograph M6). Fabric color and color change (fading) before and after the laundering were determined spectroscopically by using a Konica MINOLTA Chroma meter, model CR400. Samples of polyester fabric dyed by the two dyes and subject to the laundering test are illustrated in
[0127] The results of the laundry test are summarized in Table 2, where A refers to dyes of the instant invention and B to dyes prepared from commercially available Cu-chlorophyllin. L, c, h, AE, AL refer to CIE lightness, chroma, hue, change in the overall color of the sample after laundering, and change in lightness after laundering, respectively.
TABLE-US-00003 TABLE 2 concen- tration before laundering after laundering Dye OWF L c h L c h E L A 4% 75.5 23.1 79.6 76.4 23.4 77.3 1.33 0.9 A 2% 78.8 22.6 75.2 80.4 22.6 78.0 1.94 1.6 A 0.5% 85.3 22.6 72.4 85.8 22.9 74.8 0.81 0.5 A 0.25% 85.5 22.4 67.1 86.2 22.6 67.8 0.82 0.7 B 4% 53.8 15.9 59.9 57.9 17.5 61.7 4.46 4.1 B 2% 55.6 16.5 57.8 63.5 19.0 59.3 8.29 7.9 B 0.5% 66.8 19.4 60.2 73.6 20.3 60.0 6.84 6.8 B 0.25% 77.8 22.0 60.6 81.0 22.7 61.7 3.15 3.2
[0128] The results summarized in the table show that fabric dyed by the instant invention has a significantly deeper hue (by about 20% for the deeper shades) than fabric dyed by dye based on commercially-available Cu-chlorophyllin.
[0129] It is also clear from the results summarized in the table that the dye of the invention disclosed herein is significantly more durable during laundering than a dye prepared from commercially available Cu-chlorophyllin. In contrast to the fabric dyed using the dye prepared from commercially available Cu-chlorophyllin (average E=1.230.46), the color change after laundering the fabric dyed by the invention herein disclosed was imperceptible or barely perceptible (average E=5.692.00), a change in color E>2 being the threshold for perception by most people.
[0130] The larger the value of L, the more fading the fabric underwent during the laundering. It is clear from the results that fabric dyed by the dye of invention herein disclosed is significantly more durable to laundering than fabric dyed by dye prepared from commercially available Cu-chlorophyllin, the average values of L being 0.930.41 and 5.501.92, respectively.
Example 7
[0131] The light fastness of fabrics dyed with the two dyes was tested by using the accelerated sunlight xenon test procedure. ADIDAS Laboratory Procedure FT-11 was used to measure the fading of the fabric samples on exposure to light. An ATLAS Suntest XLS+light was set to an irradiance of 550 W/m.sup.2 and a Black Standard Temperature of 70 C. Fabric color change (fading) after exposure to light was determined by using a Konica MINOLTA Chroma meter, model CR 400.
[0132] The results of the tests are summarized in Tables 3-6 for different levels of light exposure. CIE L, a, and b values, as well as values of AE and AL prior to and following each test are given.
TABLE-US-00004 TABLE 3 concen- Before After light exposure tration light exposure 3960 kJ/m.sup.2 Dye OWF L a b L a b E L A 4% 75.5 4.2 22.7 76.3 5.4 22.4 1.38 0.8 A 2% 78.8 5.8 21.9 78.9 7.1 21.8 1.30 0.1 A 0.5% 85.3 6.8 21.5 85.3 8.2 21.8 1.25 0.0 A 0.25% 85.5 8.7 20.6 85.6 10.0 20.5 1.22 0.1 B 4% 53.8 8.0 13.8 56.8 8.8 14.6 2.94 3.0 B 2% 55.6 8.8 14.0 62.8 9.5 16.6 6.60 7.2 B 0.5% 66.8 9.6 16.8 68.9 9.9 16.4 1.73 2.1 B 0.25% 77.8 10.8 19.2 79.9 10.9 19.3 1.47 2.1
TABLE-US-00005 TABLE 4 concen- Before After light exposure tration light exposure 7920 kJ/m.sup.2 Dye OWF L a b L a b E L A 4% 75.5 4.2 22.7 76.7 5.3 22.4 1.45 1.2 A 2% 78.8 5.8 21.9 78.8 7.9 22.0 2.00 0.0 A 0.5% 85.3 6.8 21.5 85.7 9.0 22.0 1.96 0.4 A 0.25% 85.5 8.7 20.6 85.5 11.0 20.7 2.05 0.0 B 4% 53.8 8.0 13.8 58.9 9.5 14.0 4.96 5.1 B 2% 55.6 8.8 14.0 65.2 10.1 16.4 8.55 9.6 B 0.5% 66.8 9.6 16.8 69.9 10.3 15.9 2.66 3.1 B 0.25% 77.8 10.8 19.2 81.5 11.5 18.9 2.67 3.7
TABLE-US-00006 TABLE 5 Before After light exposure concentration light exposure 11880 kJ/m.sup.2 Dye OWF L a b L a b E L A 4% 75.5 4.2 22.7 77.5 5.7 22.6 2.08 2.0 A 2% 78.8 5.8 21.9 78.9 8.2 22.1 2.26 0.1 A 0.5% 85.3 6.8 21.5 85.4 9.2 22.0 2.12 0.1 A 0.25% 85.5 8.7 20.6 86.0 11.0 20.7 2.07 0.5 B 4% 53.8 8.0 13.8 59.2 9.6 14.5 5.22 5.4 B 2% 55.6 8.8 14.0 67.4 10.1 16.3 10.28 11.8 B 0.5% 66.8 9.6 16.8 72.1 10.5 16.8 4.21 5.3 B 0.25% 77.8 10.8 19.2 82.4 11.6 18.9 3.28 4.6
TABLE-US-00007 TABLE 6 After light exposure concentration Before light exposure 19800 kJ/m.sup.2 Dye OWF L a b L a b E L A 4% 75.5 4.2 22.7 77.4 6.5 22.7 2.63 1.9 A 2% 78.8 5.8 21.9 79.5 8.8 22.3 2.81 0.7 A 0.5% 85.3 6.8 21.5 85.6 10.0 22.1 2.81 0.3 A 0.25% 85.5 8.7 20.6 86.5 11.8 20.6 2.84 1.0 B 4% 53.8 8.0 13.8 59.9 9.8 14.1 5.89 6.1 B 2% 55.6 8.8 14.0 68.1 10.5 16.0 10.84 12.5 B 0.5% 66.8 9.6 16.8 73.0 11.0 16.4 5.01 6.2 B 0.25% 77.8 10.8 19.2 83.4 11.9 18.6 4.03 5.6
[0133] The results shown in the tables and pictorially in