Patent Application
20060090271
The present invention is directed to processes for modifying textiles which comprise fibers. More particularly, the invention is directed to such processes which employ ionic liquid-containing compositions.
In recent years, ionic liquids have been extensively evaluated as environmental-friendly or “green” alternatives to conventional organic solvents for a broad range of organic synthetic applications. Ionic liquids offer some unique characteristics that distinguish them from conventional organic solvents, such as no effective vapor pressure, a broad liquid range, high polarity and charge density, can be either hydrophobic or hydrophilic, and unique solvating properties.
One widely studied class of ionic liquids includes imidazolinium salts, such as butylmethylimidazolinium hexafluorophosphate, also known as BMIM/PF6. Other well known ionic liquids include N-1-ethyl 3-methylimidazolinum chloride aluminum (III) chloride, which is usually referred to as [emim]Cl-AlCl3; and N-butyl pyridinium chloride aluminum (III) chloride, which is usually referred to as [Nbupy]Cl-AlCl3. A broad range of ionic liquids have also been investigated in the following references: WO 03/029329; WO 03/074494; WO 03/022812; WO 2004/016570; US 2004/0035293A1; and U.S. Pat. No. 5,827,602.
In addition to chemical processes, ionic liquids have also been used as microbiocides/plant growth regulators, as described in FR 2434156; as antistatic agents, as described in JP10-265674 and U.S. Pat. No. 3,282,728; and as fruit and vegetable produce treating agents, as described in WO 01/19200. Other uses of ionic liquids are disclosed in U.S. Pat. No. 6,048,388 as a component of an ink composition; and in J. Am. Chem. Soc., Vol. 124, pp. 4974-4975 (2002), as an agent to dissolve cellulose.
Published PCT Application WO 2004/003120 discloses ionic liquid based products suitable for use in surface or air treating compositions, and ionic liquid cocktails containing three or more different and charged ionic liquid components. The products are particularly useful in various consumer product applications, such as home care, air care, surface cleaning, laundry and fabric care applications.
Owing to various unique properties of ionic liquids, it would be advantageous to employ such materials in additional applications.
Accordingly, it is desirable to employ ionic liquid-containing compositions in textile treating processes. Particularly, the treating process provides improvements to textiles which comprise fibers, and to provide such improvements through the use of ionic liquid-containing compositions. These processes are advantageous in that they allow provision of improved properties to textiles while employing materials recognized as environmentally friendly.
The present invention is directed to processes for modifying a textile to improve its performance which comprise the steps of a) contacting a textile comprising fibers with a treating composition comprising an ionic liquid under conditions sufficient to modify at least a portion of the surface of the fibers, thereby providing a performance improvement to treated textile; b) optionally, contacting a textile comprising fibers with a composition comprising a benefit agent; and c) at least partially removing the treating composition from the textile. In specific embodiments, the surface modification comprises a partial dissolution of at least one outer layer of the fibers and/or crystal structure change in at least surfaces of the fibers. The surface modification can impart improvements to the textile or allow embedding or attachment of a benefit agent in the fibers.
Additional embodiments and advantages of the processes are described in further detail in the following detailed description.
The processes according to the present invention for modifying a textile which comprises fibers include the steps of a) contacting the textile with a composition comprising an ionic liquid under conditions sufficient to modify at least surfaces of the fibers and provide, or facilitate provision of, a performance improvement thereto; and b) at least partially removing the composition from the textile. Within the present context, a textile which comprises fibers refers to any fiber-containing textile material or product and includes, but is not limited to, loose or free fibers, yarns (including threads), woven textiles, nonwoven textiles, knitted textiles, fabric articles, and the like. Fabric articles include, but are not limited to, garments, components used in the manufacture of garments, carpets, upholstery, and the like. Additionally, the textile fibers may be formed of any natural (e.g., cellulose), regenerated (e.g., rayon), or synthetic material, or a combination thereof. In one embodiment, the textile fibers comprise a cellulosic material. In another embodiment, the fibers comprise a synthetic material, for example comprising polyester.
In some embodiments, the ionic liquid as used herein refers to a salt that has a melting temperature of about 100° C. or less, or, in an alternative embodiment, has a melting temperature of about 60° C. or less, or, in yet another alternative embodiment, has a melting temperature of about 40° C. or less. In other embodiments, the ionic liquids exhibit no discernible melting point (based on DSC analysis) but are “flowable” at a temperature of about 100° C. or below, or, in another embodiment, are “flowable” at a temperature of from about 20 to about 80° C. i.e., the typical fabric or dish washing temperatures. As used herein, the term “flowable” means that the ionic liquid exhibits a viscosity of less than about 10,000 mPa·s at the temperatures as specified above.
It should be understood that the terms “ionic liquid”, “ionic compound”, and “IL” refer to ionic liquids, ionic liquid composites, and mixtures (or cocktails) of ionic liquids. The ionic liquid can comprise an anionic IL component and a cationic IL component. When the ionic liquid is in its liquid form, these components may freely associate with one another (i.e., in a scramble). As used herein, the term “cocktail of ionic liquids” refers to a mixture of two or more, preferably at least three, different and charged IL components, wherein at least one IL component is cationic and at least one IL component is anionic. Thus, the pairing of three cationic and anionic IL components in a cocktail would result in at least two different ionic liquids. The cocktails of ionic liquids may be prepared either by mixing individual ionic liquids having different IL components, or by preparing them via combinatorial chemistry. Such combinations and their preparation are discussed in further detail in US 2004/0077519A1 and US 2004/0097755A1. As used herein, the term “ionic liquid composite” refers to a mixture of a salt (which can be solid at room temperature) with a proton donor Z (which can be a liquid or a solid) as described in the references immediately above. Upon mixing, these components turn into a liquid at about 100° C. or less, and the mixture behaves like an ionic liquid.
Some of the properties that ionic liquids possess and make them attractive alternatives to conventional solvents include: a) ionic liquids have a broad liquid range; some ionic liquids can be in the liquid form at a temperature as low as −96° C. and others can be thermally stable at temperatures up to 200° C.; this permits effective kinetic control in many organic reactions and processes; b) ionic liquids have no effective vapor pressure, thus, they are easy to handle and they reduce safety concerns where volatility could be an issue; c) ionic liquids are effective solvents for a broad range of organic and inorganic materials due to their high polarity; d) ionic liquids are effective Bronsted/Lewis acids; and e) ionic liquids can be tuned to the specific application/chemistry desired, for example, they can be selectively made to have properties ranging from hydrophilic to hydrophobic. By virtue of their high polarity and charge density, ionic liquids have unique solvating properties, and may be used in a variety of processing environments and conditions.
Nonlimiting examples of anions and cations suitable for use in the ionic liquids for the present invention are discussed in details below.
Anions
Anions suitable for use in the ionic liquids of the present invention include, but are not limited to, the following materials:
4-[N-(nonanoyl)aminohexanoyloxy]hexanoyloxybenzenesulfonate are disclosed in U.S. Pat. No. 5,891,838; U.S. Pat. No. 6,448,430; U.S. Pat. No. 5,891,838; U.S. Pat. No. 6,159,919; U.S. Pat. No. 6,448,430; U.S. Pat. No. 5,843,879; U.S. Pat. No. 6,548,467.
Cations
Cations suitable for use in the ionic liquids of the present invention include, but are not limited to, the following materials:
wherein R1 is an acyclic aliphatic C8-C22 hydrocarbon group; in another embodiment, the cation is an alkanamide alkylene pyridinium cation having the formula:
wherein R1 is a linear or branched, saturated or unsaturated C6-C22 alkyl or alkoxy moiety, or a hydrocarbyl or substituted hydrocarbyl moiety, and R2 is a C1-C6 alkylene moiety;
Thus, the ionic liquids suitable for use herein may have various anionic and cationic combinations. The ionic species can be adjusted and mixed such that properties of the ionic liquids can be customized for specific applications, so as to provide the desired solvating properties, viscosity, melting point, and other properties, as desired. These customized ionic liquids have been referred to as “designer solvents”.
The ionic liquids can be present in various compositions suitable for use in the processes disclosed herein in any desired effective amount. Typically, the ionic liquids are present in an amount ranging from about 0.1% to about 100%, preferably from about 1% to about 85%, and more preferably from about 5% to about 75%, by weight of the textile treating composition. In some embodiments, the ionic liquids comprise at least about 50% by weight of the textile treating composition. In further embodiments, the ionic liquids comprise at least about 80% by weight of the textile treating composition, and in yet further embodiments, the ionic liquids comprise at least about 90% by weight of the textile treating composition.
Many ionic liquids are hygroscopic, thus, may contain appreciable amounts of water (referred to herein as the “innate” or “bound” water) ranging from about 0.01% to less than about 50% by weight of the ionic liquid. It should be noted that “free water” may be added in making the treating composition of the present invention. A person of ordinary skill in the art would recognize that once the components (e.g., innate water and free water) are mixed in a composition, the components can no longer be distinguished by their origin and will be reported in totality as percentage of the overall composition. Thus, the textile treating compositions of the present invention may comprise water, regardless of its origin, ranging from about 0.01% to about 50%, preferably from about 1% to about 40%, more preferably from about 5% to about 30% by weight of the composition. The treating compositions may optionally include a co-solvent. Typical examples of co-solvents include, but are not limited to, linear or branched C1-C10 alcohols, diols, and mixtures thereof. In specific embodiments, co-solvents such as ethanol, isopropanol, propylene glycol are used in some of the compositions of the present invention. In additional specific embodiments, the ionic liquid textile treating composition is substantially free of free water and/or other organic solvents. These compositions will contain less than about 10 weight percent, more specifically less than about 5 weight percent, even more specifically less than about 1 weight percent, free water and/or other organic solvents.
In some embodiments, the textile treating compositions containing ionic liquids or cocktails of ionic liquids (undiluted with adjuncts, co-solvents or free water) employed herein have viscosities of less than about 2000 mPa·s, preferably less than about 750 mPa·s, as measured at 20° C. In other embodiments, the viscosity of undiluted ionic liquids are in the range from about 0.1 to about 500 mPa·s, preferably from about 0.5 to about 400 mPa·s, and more preferably from about 1 to about 300 mPa·s at 20° C. In still another embodiment, the viscosity of textile treating composition containing ILs lowers to less than about 2000 mPa·s, preferably less than about 500 mPa·s, and more preferably less than about 300 mPa·s, when heated to a temperature in the range of about 40° C. to 60° C.
The viscosities of the ionic fluids and compositions containing them can be measured on a Brookfield viscometer model number LVDVII+ at 20° C., with spindle no. S31 at the appropriate speed to measure materials of different viscosities. Typically, the measurement is done at a speed of 12 rpm to measure products of viscosity greater than about 1000 mPa·s; 30 rpm to measure products with viscosities between about 500 mPa·s to about 1000 mPa·s; and 60 rpm to measure products with viscosities less than about 500 mPa·s. The undiluted state is prepared by storing the ionic liquids or cocktails in a desiccator containing a desiccant (e.g. calcium chloride) at room temperature for at least about 48 hours prior to the viscosity measurement. This equilibration period unifies the amount of innate water in the undiluted samples.
According to the present processes, the textile comprising fibers is contacted with the composition containing an ionic liquid (which, as noted above, may comprise a mixture or cocktail of ionic liquids) under conditions sufficient to modify surfaces of the fibers and provide, or facilitate provision of, a performance improvement thereto. A performance improvement is any physical property which is improved by the ionic liquid treatment. In one embodiment wherein the textile fibers are in contact with the ionic liquid-containing composition for a sufficient time such that the polarity and/or ionic charges, attributable to presence of IL, may interrupt hydrogen bondings between fibers, thereby crystal structure changes in at least the surfaces of the fibers may result. In another embodiment, the textile fibers are contacted by the ionic liquid-containing composition for a sufficient time such that partial dissolution of at least one outer layer of the surfaces of the fibers may result.
Dissolution of the surface layer(s) and/or changes in crystal structure can provide various improvements in physical properties of the fibers, including, but not limited to, improvements in one or more of the textile's wrinkle resistance, smoothness, softness, shape retention properties, and the like.
Further, modifications obtained according to the present processes, including, but not limited to, partial dissolution of at least one outer layer of the fibers and/or changes in crystal structure, can enable embedding and/or attachment of at least one benefit agent in the surfaces of the fibers, for example, by further contacting the textile with a composition comprising a benefit agent, either simultaneously with or subsequent to the contact with the ionic liquid-containing composition. Alternatively, the benefit agent may be present, either as an adjunct or as an ionic liquid active, in the IL-containing composition.
In one embodiment, the embedded or attached benefit agent is released from the fibers in a controlled manner (e.g., a slow and sustained release over time). In another embodiment, the benefit agent can be protected or stabilized by the ionic liquids such that the benefit agent is delivered in a controlled manner (e.g., by triggering factors, such as copious amount of water, pH change, heat).
Suitable benefit agents include, but are not limited to, perfumes, dyes, dye fixative agents, sizings, skin conditioning actives, vitamins, enzymes, surfactants, anti-abrasion agents, wrinkle resistant agents, stain resistant agents, water resistant agents, flame retardants, antimicrobial agents, metal bleach catalysts, bleaching agents, fabric softeners, anti-pilling agents, water repellant agents, ultraviolet protection agents, brighteners, mixtures thereof (i.e., of two or more of these types of benefit agents). Additional examples of suitable benefit agents are disclosed in U.S. Pat. No. 6,488,943, Beerse et al.; U.S. Pat. No. 6,548,470, Buzzaccarini et al.; U.S. Pat. No. 6,482,793, Gordon et al.; U.S. Pat. No. 6,573,234, Sivik et al.; U.S. Pat. No. 6,525,012, Price et al.; U.S. Pat. No. 6,566,323, Littig et al.; U.S. Pat. No. 6,090,767, Jackson et al.; U.S. Pat. No. 6,420, 326, Sherry et al.; U.S. Pat. No. 6,733,538, Panandiker et al.; U.S. Patent Publication No. 2003/0166495A1, Wang at al.; and U.S. Patent Publication No. 2004/0121929A1, Wang at al.
The benefit agents may be included in a textile treating composition in any desired amount. Typical textile treating compositions may contain from about 0.001 to about 20 percent by weight of the benefit agent(s). In more specific embodiments, such compositions may comprise from about 0.01 to about 10 percent by weight, and more specifically, from about 0.1 to about 5 percent by weight, of the benefit agent(s). One skilled in the art will recognize in view of the foregoing therefore that the modification may be conducted to any desired depth in the textile fibers and is not limited to surface modifications.
The processes according to the invention may be conducted in any one or combination of continuous, semi-continuous or batch processing techniques. The contacting step may be achieved in a manner known in the art, for example, including, but not limited to, by immersion techniques, or by non-immersion techniques such as spraying, misting, foaming, padding, or the like. In one embodiment, the composition is provided in the form of droplets and the textile fibers are contacted using a non-immersion technique.
Additionally, the process may be conducted during textile mill manufacture or processing, for example in a separate treatment step or during a conventional processing step, for example during a treatment such as sizing, desizing, bleaching, scouring, mercerization, dyeing, printing, finishing, coating, combinations thereof, or the like. Exemplary textile mill processes which may be employed are disclosed, for example, in U.S. Patent Application Publication No. US 2003/0226213; and in “Textile Processing and Properties: Preparation, Dyeing, Finishing and Performance”, by Vigo, Elsevier, 1994. Alternatively, the process may be conducted by a consumer on a garment, for example during home laundering or drying, or other in-home textile/garment treating processes. The specific physical conditions under which the contacting is conducted may be varied based on the particular textile fiber to be treated, the treating composition used and the desired physical property improvement thereof.
In one embodiment, energy may be applied to the textile fibers, either prior to, simultaneous with and/or subsequent to the contact with the ionic liquid-containing composition, in order to facilitate achievement and/or durability of the desired improvement. Energy may be applied in the form of heat and/or radiation, including, but not limited to microwave, infrared, ultrasonic, or combinations thereof, and the like. Additionally, the contacting step may be conducted under increased pressure, at ambient pressure, or under a reduced pressure vacuum.
The time which will be sufficient to obtain modification according to the invention will be dependent on process specifics. In one embodiment, the contact time is at least about one minute. In an alternate embodiment, the contact time is at least about five minutes. After the contacting step has been conducted for a time sufficient to modify surfaces of the fibers and provide or facilitate provision of a performance improvement thereto, the composition is at least partially removed from the textile. In one embodiment, the composition is substantially fully removed, whereby the textile comprises less than about 5 weight percent, more specifically less than about 1 weight percent, and more specifically less than about 0.1 weight percent of the ionic liquid after the removal step. The composition may be removed from the textile by any technique known in the art, including, but not limited to, rinsing with water, pressing, squeezing, padding, centrifugation, vacuum extraction, combinations thereof, and the like. In one embodiment, the composition is collected after it is removed from the textile, for example for recycle and reuse in the process.
All documents cited in the Detailed Description of the Invention are, in relevant part, incorporated herein by reference; the citation of any document is not to be construed as an admission that it is prior art with respect to the present invention.
While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.
This application claims priority under 35 U.S.C. §119(e) from Provisional Application Serial No. 60/624,053, filed on Nov. 1, 2004.
| Number | Date | Country | |
|---|---|---|---|
| 60624053 | Nov 2004 | US |
