Patent Application
20110009021
The invention relates to the use of polymers containing primary and secondary alcohols that may contain functional groups for yarn, fabric or garment colorfastness and finishing.
There is a long standing need to develop efficient, functional and non-toxic colorfast compositions which may be used to impart or improve the colorfastness properties of various materials including fabrics and garments. More specifically, a need exists to improve the colorfastness of dyed and printed materials, which include, but are not limited to, yarns, fabrics or garments which utilize dyes and pigment colors which are relatively weak in both dry and wet colorfastness.
In the past, manufacturers who wanted to improve the colorfastness properties of a material were required to subject the material to additional washing cycles, use transition metals, use heavy crosslink resin add-on, or use harsh chemicals to remove any un-reactive and/or excessive dye. For example, “stone-washing” is used in the removal of indigo dye in denim goods. “Stone-washing” requires that the denim goods being combined with both stones and caustic chemicals for a period of at least six hours. The caustic chemicals are in fact damaging to the cotton fabric and the process is excessively time consuming. These techniques are environmentally unfriendly, limited in their performance of achieving a colorfast material or fabric and limit the depth of shade of a garment. Additionally, changes in both government regulations and industry standards for colorfast fabrics, garments, and other materials require new technologies and methods to achieve the results mandated.
Hence, a need exists for a colorfast fabric which is both environmentally friendly and superior in its colorfast properties. A need also exists for a colorfast composition having at least the same characteristics as the previously mentioned colorfast fabric as well as a method for producing the above colorfast fabric.
A colorfast textile comprising a yarn, fabric and/or garment, and a colorfast composition including a polyvinyl alcohol, polyvinyl alcohol copolymer or combinations thereof.
The present invention relates to colorfast textiles which include yarns, fabrics and/or garments and a method for producing those textiles through the use of polyvinyl alcohol, polyvinyl alcohol copolymer. More specifically, the present invention relates to a colorfast textile which is comprised of a yarn, a fabric or a garment, a dye, and a colorfast composition. The colorfast composition is comprised of a polymer containing primary and secondary alcohols that may contain functional groups (i.e., polyvinyl alcohol, polyvinyl alcohol copolymer), or a combination thereof.
Textile, as used herein, refers to fibers and filaments suitable for conversion to or use as yarns, or for the preparation of woven, knit, or nonwoven fabrics. Textiles may include yarns made from natural or synthetic fibers as well as fabrics and other manufactured products made from fibers as defined above and from yarns. Textiles may also include garments and other articles fabricated from fibers, yarns, or fabrics.
Yarn, as used herein, refers to a strand comprised of fibers, filaments, or material in a form suitable for knitting, weaving, or otherwise intertwining to form a fabric. Yarn may include, but is not limited to, (1) a number of fibers twisted together (spun yarn); (2) a number of filaments laid together without twist (a zero-twist yarn); (3) a number of filaments laid together with a degree of twist; or (4) a single filament with or without twist (a monofilament).
Fabric, as used herein, refers to a planar textile structure produced by interlacing fibers, filaments, or yarns. A fabric may be a woven, knit, nonwoven, or multi-layer modular industrial fabric. Fabrics may be comprised of materials which include, but are not limited to, natural fibers such as cotton (i.e., denim, dungaree), wool, bast, silk and synthetic fibers such as acrylic, polyester, elastane (spandex), nylon, tri-acetate, polyurethane, acetate or blends thereof. Blends can include combinations of natural and/or synthetic fibers. Garment, as used herein, refers to any article which may be created or constructed using one or more fabrics or yarns.
Dye, as used herein, refers to a substance which adds color to yarns, fabrics, textiles, or garments. Dyes may include, but are not limited to, acid dyes, basic dyes, direct dyes, mordant dyes, sulfur dyes, vat dyes, indigo dyes, azoic dyes, reactive dyes, disperse dyes, natural dyes, pigments, and anthraquinone dyes. The dyes on fibers are held on to the fiber through physical entrapment and chemical forces which include hydrogen bonding, van der Waals interactions or can also be chemically bound through ionic forces and covalent bonds. Dyeing, as used herein, refers to a process of coloring yarns, fibers, fabrics, or garments with either natural or synthetic dyes. Dyeing may be carried out by any process known in the art which includes, but is not limited to, a batch (i.e. exhaust) process, or a continuous process.
One embodiment of the instant invention may utilize a yarn, fabric or garment dyed with an indigo dye. Indigo, has been used to dye cellulose-based textiles, such as cotton, for centuries despite the fact that indigo has limited affinity for cotton and must rely on physical entrapment and weak molecular forces. Additionally, indigo is insoluble in water, ether, alcohol, and dilute acids, so conventional dyeing processes require that it first be reduced prior to the dyeing process. A rope of yarns, fabric or garment is then submerged within an indigo dyebath for a period of time after which the fabric or garment is removed. Upon removal, the indigo dye is subjected to oxidation through contact with oxygen which causes the indigo to revert to its insoluble form. Because of indigo's low affinity for cellulosic materials, these steps are repeated as often as needed to obtain the desired shade of blue, with repeated immersions typically being used, and with each of these immersions being followed by an oxidation process. Excess indigo dye is then removed from the surface of the fabric or garment via water washing in order to improve its crockfastness. The present invention may be applied to dyed cotton yarns or fabrics which include both denim and dungaree.
The term colorfastness specifically relates to the resistance of a material (textile) to change in any of its color characteristics as a result of the exposure of the material to any environment that may be encountered during processing, testing, storage or use of the material. Environments or items which may effect colorfastness include, but are not limited to, water, dry cleaning, perspiration, light, accelerated laundering, pH changes, abrasions and crockfastness. The terms crock, crockfast, and crockfastness relate to the transfer of colorants from the surface of the yarn, fabric or garment to another surface or to an adjacent area of the same fabric through physical force or rubbing. Crockfast, as used herein, refers to the resistance of color transfer or bleeding to adjacent surfaces as a result of the exposure of a colored or dyed fabric or garment to any environment that may be encountered during the processing, testing, storage, or use of the fabric or garment. Testing for wet or dry crockfastness is a method for determining whether or not, and to what degree, a color may be transferred from the surface of a colored/dyed fabric or garment to another surface by rubbing.
Crockfast composition, as used herein, refers to a chemical composition which may be applied to a yarn, fabric, fiber or other textile item during manufacture of the yarn, fabric, or the garment, to improve its crockfastness. More specifically, a crockfast composition may be comprised of a polyvinyl alcohol, a polyvinyl alcohol copolymer, an ethylene vinyl alcohol, an ethylene containing polyvinyl alcohol or a combination thereof, which are discussed in greater detail below. The crockfast composition may also include a catalyst, a defoaming agent, an anti-foaming agent, and/or a softening agent which are described in greater detail below.
The polymer mentioned above may have the following molecular structure:
wherein: R1-R6 being selected from the group comprising: hydrogen, C1-C4 alkyl, C1-C4 alkoxy, acetate, hydroxyl, carbocyclic, heterocyclic or combinations thereof); and X and Y being selected from the group comprising: hydroxyl, acetate, amine, amide, sulfonate, carboxylate, heterocyclic or combinations thereof.
For the present invention, any known process may be utilized in order to synthesize the polyvinyl alcohol or polyvinyl alcohol copolymers. For example, the polyvinyl alcohol copolymers may be formed through processes which include, but are not limited to, free radical polymerization, grafting or redox initiation. Polyvinyl alcohol copolymers are described in U.S. Pat. No. 5,300,566 and U.S. Pat. No. 5,632,977, both of which are incorporated herein by reference.
In one embodiment, polyvinyl alcohol is manufactured from vinyl acetate monomer via a multi-step process. Vinyl acetate monomer is polymerized into polyvinyl acetate and then converted to polyvinyl alcohol. Polyvinyl alcohol is particularly advantageous to colorfastness because it is a safe, biodegradable, water soluble polymer. The above polyvinyl alcohol may have a molecular weight in the range of 1,000 to 1,000,000, more preferably in the range of 20,000 to 150,000. The above polyvinyl alcohol may be used in a concentration ranging from 0.1 to 50 grams per liter (g/L) when mixed with water.
In another embodiment, a copolymer of polyvinyl alcohol and N-vinyl formamide is formed by polymerizing a vinyl acetate monomer and an N-vinyl formamide monomer and then saponifying a copolymer of vinyl acetate and N-vinyl formamide. For example, a copolymer of vinyl acetate and N-vinyl formamide may be formed by combining the monomers within a reactor in the presence of a free radical initiator and an alcohol, such as methanol. The resulting reaction yields an intermediate vinyl acetate random copolymer containing vinyl formamide groups in an amount from about 1 mole percent to about 50 mole percent.
The resulting vinyl acetate and N-vinyl formamide copolymer is then subjected to saponification. The copolymer is saponified by subjecting the copolymer to heat in the presence of an alkali material. The alkali material may be selected from the group which includes, but is not limited to, any suitable base such as sodium hydroxide, potassium hydroxide, or an alkali metal alkolate. Saponification can be carried out in a continuous system, a semi-batch system, or in a batch system. In one embodiment, an alkali may be added to one of the above described copolymers in a caustic mole ratio (CMR, ratio of base to acetate groups on the polymer) in an amount from about 0.01% to about 0.1%. The copolymer is then heated to a temperature of from about 20° C. to about 50° C. and for a period of time of from about 5 minutes to about 24 hours. During saponification, the vinyl acetate is converted into a vinyl alcohol. The degree of saponification may be controlled and adjusted by controlling the saponification conditions. However, it is common that 95% or more of the available vinyl acetate units are converted into vinyl alcohol.
After saponification, the resulting product can be subjected to various washing steps in order to remove any acetates or other impurities. The resulting polyvinyl alcohol and N-vinyl formamide copolymer can have the following general formula:
where: a is from about 0 to about 15 mole %; b is from about 0.1 mole % to about 99 mole %; and c is from about 0.1 mole % to about 99 mole %. In another embodiment, a is from about 0 to about 15 mole %; b is from about 0.1 mole % to about 100 mole %, and c is from about 0.1 mole % to about 100 mole %. The above copolymer may have a molecular weight in the range of 1,000 to 1,000,000, more preferably in the range of 20,000 to 250,000.
As shown above, the copolymer can be formulated to only contain free hydroxyl groups and free amide groups. Copolymers made according to the above formula may be used in accordance with the present invention and have been found to provide specific advantages in some embodiments. For example, the above described copolymer is well suited for blending with emulsifiers.
In another embodiment, the above polyvinyl alcohol and N-vinyl formamide copolymer can be further hydrolyzed by either an acid or a base in order to incorporate amine groups into the copolymer. The hydrolysis of the polyvinyl alcohol and N-vinyl formamide copolymer may be conducted in a continuous system, a semi-batch system, or in a batch system in the presence of an acid or base to serve as a catalyst. Hydrolysis can be conducted on the copolymer in a slurry in the presence of a solvent. The solvent may comprise an alcohol, such as methanol. Of particular advantage, hydrolysis can be controlled in order to produce a copolymer having properties tailored to a particular application. Thus, the hydrolysis can be either substantially complete or partial.
When hydrolysis of the copolymer occurs in the presence of a base, the base may be selected from a group which includes, but is not limited to, an alkali hydroxide or an alkaline earth hydroxide. In one embodiment, hydrolysis is carried out in the presence of either sodium hydroxide or potassium hydroxide. The base is present in an amount from about 0.5 to about 3 times the stoichiometric quantity of N-vinyl formamide groups present. Hydrolysis can also be carried out at elevated temperatures, such as from about 50 to about 80° C. The resulting product can be recovered by filtration or solvent evaporation. In another embodiment, the base is present in an amount from about 1 to about 1.5 times the stoichiometric quantity of N-vinyl formamide groups present.
Hydrolysis of the polyvinyl alcohol and N-vinyl formamide copolymer may also occur in the presence of various acids which include, but are not limited to, halogen acids, citric acid, succinic acid, trifluoroacetic acid and methane sulfonic acid. In one embodiment, hydrolysis is carried out in the presence of hydrochloric acid. Acid hydrolysis may be conducted at a temperature of from about 15° C. to about 80° C. The acid may be present in an amount from about 0.5 to about 3 times the stoichiometric amount of N-vinyl formamide groups present. In another embodiment, the acid may be present in an amount from about 1 to about 1.5 times the stoichiometric amount of N-vinyl formamide groups present. Acid hydrolysis may also be conducted in a methanol suspension.
After hydrolysis, a copolymer having the following formula can be formed:
Where: a is from about 0 mole % to about 15 mole %; b is from about 0.1 mole % to about 99 mole %; c is from about 0 mole % to about 30 mole %; and d is from about 0.1 mole % to about 50 mole %. In another embodiment, a is from about 0 to about 15 mole %; b is from about 0.1 mole % to about 100 mole %, c is from about 0.1 mole % to about 30 mole % and d is from about 0.1 mole % to about 50 mole %. The above copolymer may have a molecular weight in the range of 1,000 to 1,000,000, more preferably in the range of 20,000 to 250,000.
Catalyst, as used herein, refers to a chemical substance which either increases or decreases the rate of a chemical reaction. A catalyst may be combined with a polyvinyl alcohol, a polyvinyl alcohol copolymer or combinations thereof. In one embodiment of the present invention, a catalyst may be used in conjunction with a defoaming/anti-foaming agent and/or a softening agent. In another embodiment, sodium bisulfate (NaHSO4) may be used as a catalyst. In the present invention, the concentration of the catalyst used may be in the range of 0.01 g/L to 0.10 g/L.
Defoaming/anti-foaming agent, as used herein, refers to a chemical additive that reduces and hinders the formation of foam in a liquid. A defoaming/anti-foaming agent may be combined with a polyvinyl alcohol, a polyvinyl alcohol copolymer, or combinations thereof. A defoaming/anti-foaming agent may be used to increase process speed and reduce other problems that foam may cause in industrial processes. A defoaming/anti-foaming agent may address problems with both surface foam and entrained/entrapped air. A wide variety of chemical formulas are available to promote coalescence of foam. Defoaming/anti-foaming agents include, but are not limited to, oil-based defoaming agents, powder defoaming agents, water-based defoaming agents, silicone based defoaming agents (i.e., HL-36, Fumerol), ethylene oxide/propylene oxide (EO/PO) defoaming agents, or combinations thereof. In one embodiment of the present invention, a defoaming/anti-foaming agent may be used in conjunction with a catalyst and/or a softening agent at 0.1 g/L to 10 g/L.
Softening agent, as used herein, refers to a substance which may be combined with a polyvinyl alcohol, a polyvinyl alcohol copolymer, or combinations thereof. Softening agents may include anionic softening agents, cationic softening agents, nonionic softening agents, silicone based softening agents, or combinations thereof. In one embodiment of the present invention, a softening agent may be used in conjunction with a catalyst and/or a defoaming agent at 0.1 g/L to 50 g/L.
It has been surprisingly found that the present invention also enhances several comfort related properties in addition to improving the colorfastness of a textile. Comfort related property, as used herein, refers to one or more attributes which may be imparted on a yarn, fabric or garment by the colorfast composition. These attributes include, but are not limited to anti-microbial functionality, appearance (i.e. luster), feel (i.e. thickness), hand (i.e. smoothness), strength (i.e. shear, burst or tensile strength), soil release properties, compression properties, bending properties, or combinations thereof.
Another embodiment of the present invention relates to a colorfast yarn, fabric or garment which is comprised of a yarn, a fabric and/or a garment and a colorfast composition. The colorfast composition is comprised of a polyvinyl alcohol copolymer. In still another embodiment of the present invention, the polyvinyl alcohol/polyvinylalcohol copolymers may act as binders for finishing. That is to say that the polyvinyl alcohol/polyvinylalcohol copolymers may act as an adhesive used to bind fibers or yarns together. One surprising result realized from the present invention is the synergy effect achieved between the dyes (mentioned above) and the polyvinyl alcohol and/or polyvinyl alcohol copolymer. When combined, the polyvinyl alcohol and/or polyvinyl alcohol copolymer acts as both dye carrier and a dye fixative. That is to say, the polyvinyl alcohol and/or polyvinyl alcohol copolymer act to promote the dyeing of fibers and the setting of the dye(s) onto those fibers, yarns, fabrics or garments.
The present invention may be realized in multiple different embodiments. One particular embodiment of the present invention may comprise a colorfast fabric comprised of a dyed yarn and a colorfast composition which includes a polyvinyl copolymer, a defoaming agent, and a catalyst. The polyvinyl alcohol copolymer of the colorfast composition is comprised of a polyvinyl alcohol and an N-vinyl formamide copolymer having a molecular weight in the range of 10,000 to 250,000 and having the following molecular structure:
Where: a=0; b=90-98; c=0.1-15; and d=0-15. In another embodiment, a=90-98; c=0; and d=2-10. In still another embodiment, a=0; b=92-96; c=0; and d=4-8. In still another embodiment, a=0; b=94; c=0; and d=6.
In another embodiment, the present invention may comprise a colorfast fabric comprised of a dyed fabric and a colorfast composition which is comprised of a polyvinyl alcohol, and a defoaming agent. The polyvinyl alcohol of the colorfast composition has a molecular weight in the range of 20,000 to 250,000 and having the following molecular structure:
Where a=0-13; b=87-99.9; c=0; and d=0. In an alternate embodiment, a=0-13 b=87-100; c=0; and d=0. In another embodiment, a=0; b=84-92; c=0; and d=8-16. In still another embodiment, a=0; b=86-90; c=0; and d=10-14 and in yet another embodiment, a=0; b=88; c=0; and d=12.
In yet another embodiment, the present invention may comprise a crockfast fabric comprised of a dyed fabric and a colorfast composition which is comprised of a polyvinyl alcohol copolymer and a defoaming agent. The polyvinyl alcohol copolymer of the colorfast composition is comprised of a polyvinyl alcohol and N-vinyl formamide copolymer having a molecular weight in the range of 20,000 to 150,000 and having the following molecular structure;
Where a=0; b=90-98; and c=2-10. In another embodiment, a=0; b=92-96; and c=4-8 and in still another embodiment, a=0; b=94; and c=6.
In still another embodiment, the present invention may comprise a crockfast composition for dyed fabric comprising a polyvinyl alcohol, a polyvinyl alcohol copolymer, or combination thereof. In still another embodiment, the above embodiment may further comprise a catalyst, a defoaming agent, a softening agent, or a combination thereof.
In another embodiment, the present invention may comprise a crockfast composition for a dyed fabric comprising a polyvinyl alcohol copolymer having the following molecular structure:
Where: a=from about 0 to about 15 mole %; b=about 50 to about 99 mole %; and c=about 1 to about 50 mole %. In an alternate embodiment, a=from about 0 to about 15 mole %; b=about 50 to about 100 mole %; and c=about 1 to about 50 mole %. The above copolymer may have a molecular weight in the range of 10,000 to 200,000, more preferably in the range of 20,000 to 150,000.
In another embodiment, the present invention may comprise a crockfast composition for fabric comprising a polyvinyl alcohol copolymer having the following molecular structure:
Where: a=from about 0 to about 15 mole %; b=from about 50 to about 99 mole %; c=from about 0 to about 30 mole %; and d=from about 1 to about 50 mole %. In another embodiment, a=from about 0 to about 15 mole %; b=from about 50 to about 100 mole %; c=from about 0 to about 30 mole %; and d=from about 1 to about 50 mole %. The above copolymer may have a molecular weight in the range of 10,000 to 200,000, more preferably in the range of 20,000 to 50,000 or 60,000 to 150,000.
In yet another embodiment of the present invention, the colorfast textile is treated with the colorfast composition at the fabric finishing and garment finishing process. This use is entirely unrelated to the use of PVOH as a sizing agent. Sizing agent, as used herein, refers to compounds that are applied to warp yarn to bind the fiber together and stiffen the yarn to provide abrasion resistance during weaving. Sizing of a warp yarn is employed to reduce breakage of the yarn and thus prevent production stops on a weaving machine. On the weaving machine, the warp yarns are subjected to several types of actions i.e. cyclic strain, flexing, abrasion at various loom parts and inter yarn friction. With sizing, the strength (i.e. abrasion resistance) of the yarn will improve. The degree of improvement of strength depends on adhesion force between fiber and size, the size penetration and the encapsulation of the yarn. The sizing agent is applied on warp yarn with a warp sizing machine. After the weaving process the fabric is desized (washed).
The present invention also includes a method for using the colorfast composition as a coating to polyurethane/synthetic yarns which, unlike sizing agents used previously, does not leave a residue on the yarns, is used at a lower concentration and the PVOH-copolymers offer excellent adhesion properties.
The present invention also includes a method for producing a colorfast yarn, fabric or garments which comprises the steps of providing a dyed fabric and treating the fabric with a polyvinyl alcohol having a molecular weight in the range of 10,000 to 1,000,000 and having a concentration in the range of 0.1 to 50 grams per liter (g/L), followed by drying and/or curing the fabric.
In one embodiment of the present invention, a fabric may be subjected to drying for a time period in the range of 10 minutes to 300 minutes at a temperature ranging from 35° C. to 100° C.
In another embodiment of the present invention, a fabric may be subjected to curing for a time period in the range of 10 minutes to 300 minutes at a temperature ranging from 55° C. to 180° C.
In another embodiment, the above method may further include the step of treating the yarn, fabric or garment with an emulsifier, a catalyst, a defoaming/anti-foaming agent, a softening agent, or combinations thereof prior to drying and/or curing the fabric. The resulting crockfast yarn, fabric, or garment from any of the above described methods may have a rating of at lease 2.0 on the Gray Scale Index for Wet Crock and/or have a rating of at least 3.0 on the Gray Scale Index for Dry Crock.
The present invention also includes a method for producing a crockfast yarn, fabric or garment which comprises the steps of providing a dyed yarn, fabric or garment and treating the yarn, fabric or garment with a crockfast composition which includes a polyvinyl alcohol copolymer, as well as a catalyst, a defoaming agent, a softening agent, or combinations thereof, followed by drying and/or curing the fabric.
In one embodiment, the polyvinyl alcohol copolymer of the crockfast composition described above may have the following molecular structure:
where: a=from about 0 to about 15 mole %; b=about 50 to about 99 mole %; c=about 1 to about 50 mole %; and where the polyvinyl alcohol copolymer has a molecular weight in the range of 10,000 to 500,000. In another embodiment, a=from about 0 to about 15 mole %, b=about 50 to about 100 mole %, and c=about 1 to about 50 mole %.
In another embodiment, the polyvinyl alcohol copolymer of the crockfast composition described above may have the following molecular structure:
where: a=from about 0 to about 15 mole %; b=from about 50 to about 99 mole %; c=from about 0 to about 50 mole %; d=from about 1 to about 50 mole %; and where the polyvinyl alcohol copolymer has a molecular weight in the range of 10,000 to 500,000. In an alternate embodiment, a=from about 0 to about 15 mole %, b=from about 50 to about 100 mole %, c=from about 0 to about 50 mole %, and d=from about 1 to about 50 mole %.
In still another embodiment, the crockfast fabric of the above described method may have a lightness (L*) in the range of 50 to 100, a green-red (a*) in the range of −1 to −10, and a blue-yellow (b*) in the range of —1 to −20 according to the CIELAB measuring system. In still another embodiment, the crockfast fabric from the above described method may have a rating of at lease 2.5 on the Gray Scale Index for Wet Crock and/or have a rating of at least 3.5 on the Gray Scale Index for Dry Crock.
The present invention also includes a method for producing a crockfast yarn, fabric or garment which comprises the steps of providing a dyed yarn, fabric or garment; treating the yarn, fabric or garment with a colorfast composition including a polymer containing primary and secondary alcohols that may contain functional groups, an ethylene polyvinyl alcohol, or combinations thereof; and drying and/or curing said yarn, fabric, or garment.
The polymer described in the method above may have the following molecular structure:
wherein: R1-R6 being selected from the group comprising: hydrogen, C1-C4 alkyl, C1-C4 alkoxy, acetate, hydroxyl, carbocyclic, heterocyclic or combinations thereof); and X and Y being selected from the group comprising: hydroxyl, acetate, amine, amide, sulfonate, carboxylate, heterocyclic or combinations thereof.
The present invention also includes a rope dyeing process in which a polymer containing primary and secondary alcohols that may contain functional group is used during pre-treatment, and/or dye bath and/or post treatment stages of the vat and, or rope indigo dyeing range.
The present invention also includes a garment dyeing process in which primary and secondary alcohols that may contain functional group, ethylene polyvinyl alcohol, or combinations thereof; is used during pre-treatment, and/or dye bath and/or post treatment stages of the garment dyeing process.
The present invention also includes a method for improving the colorfastness of a yarn, fabric or garment dyed with an indigo dye comprising the steps of: a. submerging and agitating an untreated yarn, fabric or garment into a first vat containing a prewetting solution (see Indego treatment below) for a period of time ranging from 5 to 30 seconds (or ranging from 10 to 30 seconds); b. removing the untreated yarn, fabric or garment from the first vat; c. running the untreated yarn, fabric or garment through a padder having a pressure in the range of 0.5 to 2.5 bar at a speed in the range of 0.5 M/minute to 2.5 M/minute (or in the range of 1.0 M/minute to 2.0 M/minute); d. providing a second vat containing an indigo dye; e. submerging and agitating the untreated yarn, fabric or garment into the second vat for a period of time ranging from 5 to 30 seconds resulting in a treated yarn, fabric or garment (or ranging from 10 to 30 seconds); f. removing the treated yarn, fabric or garment from the second vat; g. running the treated yarn, fabric or garment through a padder having a pressure in the range of 0.5 to 2.5 bar at a speed in the range of 0.5 M/minute to 2.5 M/minute (or in the range of 1.0 M/minute to 2.0 M/minute); h. oxygenating the treated yarn, fabric or garment for a period of 30 to 120 seconds (or for a period of 45 to 120 seconds, or for a period of 45 to 90 seconds); i. repeating steps d-h one or more times; j. submerging and agitating the treated yarn, fabric or garment into a third vat containing a substance selected from the group comprising: the prewetting solution, water, polyvinyl alcohol, or combinations thereof, for a period of time ranging from 30 to 120 seconds (or for a period of 45 to 90 seconds); k. running the treated yarn, fabric or garment through a padder having a pressure in the range of 0.5 to 2.5 bar at a speed in the range of 0.5 M/minute to 2.5 M/minute (or in the range of 1.0 M/minute to 2.0 M/minute); l. oxygenating the treated yarn, fabric or garment for a period of 30 to 120 seconds (or for a period of 45 to 120 seconds, or for a period of 45 to 90 seconds); m. submerging and agitating the treated yarn, fabric or garment into a fourth vat containing a substance selected from the group comprising: the prewetting solution, water, polyvinyl alcohol, or combinations thereof, for a period of time ranging from 30 to 120 seconds (or for a period of 45 to 120 seconds, or for a period of 45 to 90 seconds); n. running the treated yarn, fabric or garment through a padder having a pressure in the range of 0.5 to 2.5 bar at a speed in the range of 0.5 M/minute to 2.5 M/minute (or in the range of 1.0 M/minute to 2.0 M/minute); o. oxygenating the treated yarn, fabric or garment for a period of 30 to 120 seconds (or for a period of 45 to 120 seconds, or for a period of 45 to 90 seconds); p. drying the treated yarn, fabric or garment for a period of 30 to 120 minutes (or for a period of 30 to 90 minutes, or for a period of 30 to 75 minutes, or for a period of 30 to 60 minutes).
In one embodiment, the above method may include a prewetting solution selected from the group comprising: a polyvinyl alcohol, a polyvinyl alcohol copolymer, a surfactant, a wetting agent, a sequestering agent, a catalyst, a defoaming agent, a softening agent, or combinations thereof.
In another embodiment of the above method, the indigo dye has a concentration in the range of 5 g/L to 25 g/L, 10 g/L to 25 g/L, or 15 g/L to 25 g/L and may have a pH in the range of 10.8 to 12.
The above method may further comprise the steps of: adjusting the pH of either the prewetting solution or the indigo dye prior to submerging the untreated yarn, fabric or garment.
In another embodiment of the above method, the pre-wetting solution may comprise a polyvinyl alcohol copolymer including a polyvinyl alcohol and N-vinyl formamide copolymer having a molecular weight in the range of 20,000 to 150,000 and having the following molecular structure:
Where a=0; b=90-98; and c=2-10. In another embodiment, a=0; b=92-96; and c=4-8 and in still another embodiment, a=0; b=94; and c=6.
In another embodiment of the above method, the pre-wetting solution may comprise a polyvinyl alcohol copolymer including a polyvinyl alcohol and an N-vinyl formamide copolymer having a molecular weight in the range of 10,000 to 250,000 and having the following molecular structure:
Where: a=0; b=84-92; c=0; and d=8-16. In another embodiment, a=0; b=86-90; c=0; and d=10-14, and in still another embodiment, a=0; b=88; c=0; and d=12.
The present invention also includes a rope dyeing process in which a polymer containing primary and secondary alcohols that may contain functional group is used during pre-treatment, and/or dye bath and/or post treatment stages of the vat and, or rope indigo dyeing range.
The present invention also includes a garment dyeing process in which primary and secondary alcohols that may contain functional group, or combinations thereof; is used during pre-treatment, and/or dye bath and/or post treatment stages of the garment dyeing process.
The present invention also includes a piece dyeing process in which a polymer containing primary and secondary alcohols that may contain functional group or combinations thereof is used during pre-treatment, and/or dye bath and/or post treatment stages of the piece dyeing process.
The following examples further illustrate the present invention. The crockfast formulations set forth in Table 1 were applied to a polyester suede fabric by a continuous method. The crockfast formulations set forth in Tables 2-5 were applied to a denim cotton fabric by an exhaustion or saturation technique. Thereafter the treated fabric was subjected to testing according to AATCC Test Method 8-2007 (using a crockmeter) and AATCC Test Method 61-2007 (using laundering), both incorporated by reference herein. CIELAB and Crockfastness Rating data was collected using a Datacolor 650™ Spectrophotometer. The results of these experimental trials are set forth in Tables 1-5.
CIELAB, as used herein, refers to a standardized method of measuring color differences. The CIELAB is a color and color difference system based on rectangular color coordinates. The system uses the variables L*, and b* which represent 3 separate axis. L* represents lightness with black being assigned a value of zero (0), white being assigned a value of one hundred (100), and gray being assigned a value of fifty (50). The variable a* provides a shade value of the color in rectangular coordinates with +a* being red and −a* being green. The variable b* provides another shade value of the color in rectangular coordinates with a +b* being yellow and a−b* being blue. The color difference (ΔE) is then provided by the equation:
ΔE*=√{square root over (ΔL*2+Δa*2+Δb*2)}
where ΔL*=L* sample−L*standard
Δa*=a*sample−a*standard
Δb*=b*sample−b*standard
Crockfastness Rating Scale, as used herein, refers to a scale which measures the transfer of color during rubbing (i.e. crocking). The loss of color is evaluated by comparison to pairs of gray standards on a Grey Scale for Staining Reference Card. One half of each standard is of identical chroma to the starting specimen. The second half of the standard ranges from the starting chroma (no loss of color) to white (loss of all color). The amount of contrast between the treated and untreated fabric is related to one of the standard pairs to yield the Crockfastness Rating. On this scale, 5 indicates that no color was transferred during crocking, and 1 indicates a heavy loading of color was transferred during crocking. AATCC Evaluation procedure 2-2007 was utilized in the present invention to measure the Gray Scale for Staining and is incorporated by reference herein.
Crockfast Rating measurements of Samples subjected to Treatments 2 and/or 3 show at least a half step improvement.
Sample 19 was laundered improving in crockfastness from 2 to 3 but also removing the indiao from the sample.
Tables 2-4 illustrate the results achieved after samples were treated with colorfast composition and then subjected to numerous washing cycles. It is clearly demonstrated that samples 12-18 achieved a superior performance to control sample 19 as demonstrated by the Crockfast Rating between 3 and 4 as compared to 3.
Table 5 summarizes the crockfast results for samples 20-37. Table 5 illustrates that samples subjected to a batch process achieved superior Crockfast Rating (3-4-4-5) to those subjected to a continuous process (2-4). Table 5 also illustrates that samples treated with colorfast composition achieved a superior Crockfast Rating to those samples that were not treated.
Tables 6 and 7 summarize the crockfast results for a single sample treated with PVOH and a softener. The sample is then washed repeatedly and measured for crockfastness after each washing cycle. Tables 6 and 7 illustrate that a sample subjected to numerous washings after treatment achieved superior Crockfast Rating (3-4-4-5). Tables 6 and 7 also illustrate that samples treated with colorfast composition achieved a superior Crockfast Rating to those samples that were not treated. Table 7 specifically illustrates the colorfast changes from an unwashed garment through twenty-four washings and clearly demonstrates that the color does not significantly diminish from washing number one to washing number twenty-four.
Table 8 summarizes the crockfast results for samples 1-10 and samples 1-1 through 1-10. Table 8 illustrates that samples treated with colorfast composition achieved a superior Crockfast Rating to those samples that were not treated.
As previously stated, the present invention relates to the use of indigo dyes. Ten samples were prepared and testing using the following procedure. An indigo dye was prepared using the following method:
a. Place 1000 mL of water in a vat
b. Add 300 g of 50% Caustic solution (NaOH) to the vat
c. Add 200 g of Sodium Hydrolsulfide 85% strength to the vat
d. Add 190 grams of indigo to the vat
e. Balance to water (add enough water to attain a total solution volume of 2 liters within the vat)
f. Seal the vat to ensure there that little to no oxygen comes into contact with the solution.
The solution above is then diluted to 15 g/L. A rope/yarn was then prepared as follows:
a. Cut five, 12 inch strips of yarn.
b. tie each rope end into a knot (as close to the end as you can get).
c. After the knots are complete, we now have a rope.
A 1 liter pre-wetting solution was created which included 1 g/L of wetting agent placed into a separate VAT #1.
PREWETTING (Triton X 100 at 0.1% solution)
Used the same procedure as Sample 1 above, however, the pH level dropped to 11.11.
PREWETTING (6% vinyl amine/94% PVOH at 5 g/L or 0.5% solids) Caustic (50% NaOH) is used to adjust pH level. Solution pH=11.12
PREWETTING (6% vinyl amine/94% PVOH at 5 g/L or 0.5% solids) Caustic (50% NaOH) is used to adjust pH level. Solution pH=11.12
PREWETTING (12% vinyl amine/88% PVOH at 2.5 g/L or 0.25% solids) Caustic (50% NaOH) is used to adjust pH level. Solution pH=11.12
PREWETTING (12% vinyl amine/88% PVOH at 2.5 g/L or 0.25% solids) Caustic (50% NaOH) is used to adjust pH level. Solution pH=11.12
PREWETTING (6% vinyl amine/94% PVOH at 2.5 g/L or 0.25% solids) Caustic (50% NaOH) is used to adjust pH level. Solution pH=11.15
PREWETTING (6% vinyl amine/94% PVOH at 2.5 g/L or 0.25% solids+Triton X100 0.5 g/L). Caustic (50% NaOH) is used to adjust pH level. Solution pH=11.17
Indigo Sample 9:
PREWETTING (6% vinyl amine/94% PVOH at 2.5 g/L or 0.25% solids+Triton X100 0.5 g/L). Caustic (50% NaOH) is used to adjust pH level. Solution pH=11.17
Master Bath pH=13.20 (Same Master Bath for All the Runs)
PREWETTING (Triton X 100 at 0.1% solution)
Table 9 illustrates the data from indigo samples 1-10 above. The differences for Samples 3-10 are relative to Control Sample 1.
Table 11 contains compression strength data from Sample Groups A and B which each contain 3 samples. The Kawabata Evaluation System (KES) is used to make objective measurements of hand properties. With low forces applied, the KES instruments measure mechanical properties that correspond to the fundamental deformation of fabrics in hand manipulation or comfort.
Table 12 contains bending rigidity datadata from Sample Groups A and B which each contain 3 samples. Bending, measured with KES-FB2 Bending Tester, is a measure of the force required to bend the fabric approximately 150°.
Table 13 illustrates the data from an industry recognized “spray test” conducted on fleece samples wherein Samples 1-3 were treated with a 30 g/L solution of PVOH and an N-vinyl formamide copolymer and Samples 4-6 were not treated. Water was then sprayed onto the samples and a visual inspection was undertaken to determine whether the water penetrated the fabric or was prevented from doing so. As can clearly be seen in the table and in
This application claims the priority of the provisional application Ser. No. 61/170,022 filed Apr. 16, 2009.
| Number | Date | Country | |
|---|---|---|---|
| 61170022 | Apr 2009 | US |
