Cationization of textiles by padding and drying

Abstract

A method and system for cationizing and dyeing natural fiber-containing textiles using a mono- or di-quaternized cationizing agent is described. The method includes heating the textile to a temperature ranging from 90°C to less than 110°C for a period ranging from 1 minute to 10 minutes to allow the cationizing agent to react with the textile. The cationization step in the presence of heat using the halogenated cationizing agent of the present invention promotes improved dyeing.

Description

[Technical Field]

[0001] The present disclosure relates to processes and systems for the cationization of natural fiber-containing (e.g., cotton-based) textiles that can be used to improve dye association with the cationized textiles. [Background technology]

[0002] Textile dyeing is the process of applying pigments or dyes to textile materials such as fabrics, yarns, and fibers. Desirably, the dyeing process is efficient and rapid, providing dyed textiles with the desired degree of coloration and resistance to dye fading and discoloration (colorfastness). Furthermore, the dyeing process and the materials used therein preferably do not adversely affect aspects of the textile, such as its flexibility, durability, and tactile properties such as softness, smoothness, and stiffness. Various dye types are used depending on the textile material (e.g., natural, synthetic, or a mixture thereof) and the desired color.

[0003] Common dyes for cotton have a negative charge. However, in aqueous solution, the surface of cotton fibers has a neutral or mildly negative charge due to the presence of hydroxyl groups in the cellulosic material that makes up cotton. Negatively charged dyes are repelled by the negatively charged cellulosic material, resulting in less dye uptake by the cotton. To dye textiles, the surface properties of the cotton fibers must be modified so that the dye is not repelled. Traditional dyeing of cotton-based textiles involves the use of a mixture of salts, alkalis, and dyes to cause the dye to associate with the cotton fiber material. Salts are commonly used in dye baths to reverse the charge on the cotton fibers, and alkalis are used to allow the dye to react with and associate with the induced positively charged surface of the cotton fibers. However, these traditional processes can consume significant amounts of water, energy, and chemicals, which is undesirable.

[0004] As an alternative to salt and alkali treatments, processes for modifying cotton fibers using cationic reagents are known in the art. Cationic reagents with the appropriate chemistry can react with chemical groups on cellulose to provide a permanent cationic (positive) charge on the surface of cotton fibers ("cationic cotton"). The positive surface charge on cotton fibers allows them to associate with a wider variety of dyes and can also allow for a wider range of color variations (e.g., color depth). Cationization processes for cotton-based textiles can also consume less water, energy, and chemicals, making them desirable for industrial-scale operations.

[0005] One type of cationizing agent is 3-chloro-2-hydroxypropyl trimethyl ammonium chloride (CHTAC) (see, e.g., U.S. Pat. No. 7,201,778; Hashem, M., et al., Textile Res. J., 73:1017, 2003). CHTAC can react with the hydroxyl groups of cellulose in the presence of a base. In the first step, CHTAC is dechlorinated to form the reaction intermediate epoxypropyl trimethyl ammonium chloride (EPTAC), whose epoxide group reacts with the deprotonated hydroxyl groups of cellulose, thereby covalently binding the cationic ammonium chloride group to the cellulose backbone through an ether bond. However, there is a competing reaction with water molecules that hydrolyzes the epoxide groups of EPTAC, producing the waste product 2,3-dihydroxypropyl trimethyl ammonium chloride (2,3-DHTAC). Therefore, the formation of 2,3-DHTAC is desirably minimized. Performing a "batch" treatment of textiles in the presence of a base and a cationizing agent at lower temperatures and for longer periods of time allows for better reaction of the cationizing agent with the fibers and minimizes waste formation, but such long-term treatment steps are not practical for commercial operations.

[0006] Attempts to reduce the use of chemicals such as salt, alkali, and water to produce and dye cationic cotton are made to improve the dyeing of textiles. Accordingly, the disclosed methods and systems improve the cationization of textiles, such as textiles comprising natural fibers such as cotton, while reducing the use of chemicals in the process. The cationized textiles can then be used as improved substrates in dyeing processes to provide textiles with better color properties. Summary of the Invention

[0007] The present disclosure provides methods and systems for enhancing the cationization of textiles comprising or derived from natural fibers, such as cotton. The processes of the present disclosure form improved cationized textiles that enhance subsequent textile dyeing and improve the properties, such as color, of the dyed textile.

[0008] Using the process described herein, cationization of textiles can be carried out in a short period of time with good results and reduced waste. Hydrolysis of the cationizing agent is minimized, improving its reaction with the textile. Subsequent dyeing of the cationized textile provides desirable color and colorfastness. The process, in turn, improves reagent usage by producing less waste, saves energy by minimizing processing time, and improves overall industrial processing efficiency.

[0009] In one aspect, the present disclosure provides a method for cationizing a textile comprising natural fibers or derivatives thereof. The method comprises treating the textile comprising natural fibers or derivatives thereof with an aqueous solution comprising an alkali metal hydroxide and a mono- or di-quaternized cationizing agent. The textile is then heat-treated at a temperature ranging from 90°C to less than 110°C for a period ranging from 1 minute to 10 minutes to allow the cationizing agent to react with the textile.

[0010] In an embodiment, the textile is treated at a temperature ranging from 90°C to 109°C for a period ranging from about 2 to 8 minutes. In an embodiment, the textile is treated at a temperature ranging from 90°C to 105°C for a period ranging from about 2 to 8 minutes.

[0011] In some embodiments, after treating the textile with an aqueous solution containing an alkali metal hydroxide and a cationizing agent, a portion of the aqueous solution is mechanically removed from the textile.

[0012] In some embodiments, the aqueous treating and mechanically removing steps are carried out at a temperature of less than 35° C. and for a total period of 1 minute or less.

[0013] The steps of treating with aqueous solution, mechanically removing, and heat treating the textile may be carried out for a period of time of 11 minutes or less in total, such as in the range of 1 minute to 11 minutes, in the range of 1 minute to 8 minutes, or in the range of 1 minute to 8 minutes, which significantly enhances textile throughput while simultaneously providing good cationization and incorporated nitrogen content of the textile, which in turn facilitates the subsequent dyeing process.

[0014] In some embodiments, after steam treatment, the textile is then neutralized with an acid-containing solution, after which the cationic textile can be dyed in a composition containing a dye using the same system used for padding and heat treatment, or can be dyed using a different system.

[0015] Exemplary cationizing agents include mono-quaternized nitrogen compounds capable of generating a single epoxide group in the presence of an alkali metal hydroxide, such as 3-chloro-2-hydroxypropyltrimethylammonium chloride. Other exemplary cationizing agents include di-quaternized nitrogen compounds capable of generating two epoxide groups in the presence of an alkali metal hydroxide, such as bis-ether halide di-hydroxylated di-quaternized ammonium compounds, such as bis[(3-chloro-2-hydroxypropyldialkylammonium)alkyl]ether dichloride.

[0016] Such bis-based compounds are preferred because, when used in conjunction with the methods of the present disclosure, they can promote cationization and dyeing with significantly reduced chemical, water, energy, and wastewater production, while simultaneously promoting the formation of dyed textiles having desirably vibrant, striking, and long-lasting colors.

[0017] In embodiments, the solution has a molar ratio of alkali metal hydroxide to cationizing agent of 3.5:1 or greater, or 8.0:1 or less, such as in the range of 3.5:1 to 8.0:1, or 3.75:1 to 7.5:1. In other embodiments, the solution has a molar ratio of alkali metal hydroxide to cationizing agent of greater than 1:1, such as in the range of 1.8:1 to 5:1, or 2.0:1 to 4.5:1.

[0018] In another aspect, the present disclosure provides a system for cationizing and dyeing textiles comprising natural fibers or their derivatives. The system includes a padding bath configured to allow treatment of textiles comprising natural fibers or their derivatives in an aqueous solution in the padding bath, the solution including an alkali metal hydroxide and a mono- or di-quaternized cationizing agent. The system also includes a solution remover for removing the aqueous solution from the padded textile after treatment in the padding bath, and a conveyor device capable of moving the textile through the padding bath and the solution remover in about 1 minute or less. The system also includes a heat treatment device configured to treat the padded textile at a temperature ranging from 90°C to less than 110°C for a period ranging from 1 minute to 10 minutes to react the cationizing agent with the textile. The system may also include a neutralization bath for neutralizing the textile with an acid-containing solution. The system may include a process controller, such as a computer-based controller, that can be programmed to execute the treatment methods described herein. Optionally, the system may include a dye bath for dyeing the cationized textile. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 1 is a diagram of an exemplary system for cationization and dyeing of textiles. [Figure 2] 1 is a graph of nitrogen content on cationized cotton when prepared using a di-quaternized cationizing agent at different heating conditions and times versus cold batch processing. [Figure 3]1 is a graph of nitrogen content on cationized cotton when prepared using a di-quaternized cationizing agent at different heating conditions and times versus cold batch processing. DETAILED DESCRIPTION OF THE INVENTION

[0020] The embodiments of the present invention described below are not intended to be exhaustive or to limit the invention to the precise forms disclosed in the following detailed description. Rather, the embodiments are chosen and described so that others skilled in the art can appreciate and understand the principles and practices of the present invention.

[0021] All publications and patents mentioned herein are incorporated herein by reference. The publications and patents disclosed herein are provided solely for their disclosure. Nothing herein should be construed as an admission that the inventors are not entitled to antedate any publication and / or patent, including any publication and / or patent cited herein.

[0022] The term "about" used preceding any numerical value in this disclosure or the appended claims allows for some slight imprecision in the stated numerical value, which imprecision may be understood in the art or may result from the measurement method (e.g., chemical or physical measurements, etc.) used to obtain such numerical value, and any numerical value in this disclosure or the appended claims not preceded by the term "about" may also be understood in the same way.

[0023] Methods and compositions of the present disclosure described as "comprising" or "including" may include the recited steps and compounds, respectively, and may optionally include other steps and components. When a method or composition of the present disclosure is described as "consisting of," the method or composition has the recited steps or compounds, but does not include steps or compounds not recited. The term "consisting essentially of" generally refers to a composition containing the recited compounds, and may include other unrecited compounds, but in insubstantial amounts. For example, such a composition may contain one or more other unrecited components, but not in amounts greater than about 1% (by weight), greater than about 0.5% (by weight), or greater than about 0.1% (by weight) of the total composition. A composition "consisting of" recited components means that no other components other than the recited components are present in measurable amounts, or a method "consisting of" certain steps does not include steps other than those recited.

[0024] The present disclosure describes a method and system for cationizing textiles comprising natural fibers, such as cotton, or their derivatives. The cationization process can be carried out in a relatively short period of time, produces low levels of waste, and uses minimal energy. The method and system involves treating the textile in an aqueous solution (which may also be referred to as a "padding" solution) containing an alkali metal hydroxide and a cationizing agent, such as a mono- or di-quaternized nitrogen compound, capable of generating one or more epoxide groups, respectively, in the presence of the alkali metal hydroxide.

[0025] In some embodiments, the padding treatment can be carried out quickly, for a period of one minute or less, and at a temperature, such as ambient temperature, that does not require heating of the aqueous solution. In some embodiments, after padding, excess solution is removed from the textile, and the textile is then introduced into a heating device to cause the cationizing agent to react with the textile. The heat treatment can also be carried out relatively quickly and within a defined temperature range. In particular, the textile is heated at a temperature ranging from 90°C to less than 110°C for a period ranging from one minute to ten minutes. In some embodiments, more specific temperature and time ranges can be used.

[0026] Advantageously, good cationization is achieved without the need for the long padding and reaction times (such as periods of time) characteristic of cold batch padding processes. Instead, the treatment temperatures and times of the present disclosure have been discovered to provide good cationization of textiles while minimizing loss of reagents due to hydrolysis.

[0027] The cationization method of the present disclosure prepares the textile in an excellent condition for dye association, and the dyeing process can, in turn, provide good coloration of the textile. Textile dyeing can be carried out using a different system or with the same system used for padding and heat treating described herein.

[0028] A "system" according to the present disclosure includes devices ("system components") that enable the method of the present disclosure to be carried out. The system may include one or more of the following devices: baths for holding treatment solutions (padding bath, washing bath, neutralizing bath, and / or optionally dyeing bath); textile moving devices such as conveyors including rollers; solution removal devices such as roller pairs; heating devices for padded textiles; and control devices such as computer-based operating units.

[0029] The steps of the methods of the present invention may be carried out using a continuous process, a semi-continuous process, a batch process, or a combination thereof.

[0030] One option for processing textiles is to use a continuous process. A continuous process is a flow product method used to manufacture, process, or produce an article while avoiding process flow stoppages. In a continuous process, the article being processed or manufactured is moving. In continuous textile processing, the textile is often in the form of a sheet that is moved through two or more processing areas (e.g., "processing zones"), and the sheet is subjected to different chemical, mechanical, and / or physical processes in each processing area while being moved. The movement of the textile in a continuous process can be facilitated by system devices such as a textile conveyor having rollers that contact and facilitate the movement of the textile in the continuous process. A continuous process can be carried out using the system of the present disclosure described herein.

[0031] In embodiments, two or more steps of the disclosed method may be described as a continuous process. For example, in the steps of padding a textile in a solution of a base and a cationizing agent, mechanically removing a portion of the solution from the padded textile, and then heat-treating the textile, the textile may be continuously moved through a treatment zone, which provides a predetermined treatment of the textile during movement. Other steps in the cationization and dyeing process (e.g., washing, neutralization, and / or optional dyeing) may also be described as continuous or optionally discontinuous. Figure 1 shows a system that can be used for continuous treatment of textiles according to the disclosed method.

[0032] A semi-continuous process may include one in which a flow product operation (continuous) is stopped and then restarted after a period of time. In some embodiments, two or more steps of the methods of the present disclosure may be described as semi-continuous processes. For example, depending on the desired processing conditions, textile movement may be stopped in a processing zone for a period of time and then restarted to remove the textile from the processing zone. The methods of the present disclosure may use a semi-continuous process in which textile movement is stopped in a thermal processing device for a period of time and at a temperature, as described herein, suitable for reaction of the cationizing agent with the textile, and then textile movement is resumed after that period to remove the textile from the thermal processing device. Semi-continuous processes may be implemented in the systems of the present disclosure described herein.

[0033] Optionally, in embodiments, one or more steps in the methods of the present disclosure may be performed in a batch process. For example, before or after the processing steps of the present disclosure, the textile may be modified to be configured for use in a batch process rather than a continuous process. The modification may be performed by cutting the textile and then providing textile portions for use in one or more batch processing steps. In a batch process, the system may include equipment configured to prevent the textile from being automatically transferred from one device to another otherwise associated with continuous processing equipment. For example, in a system including equipment for batch processing steps, system features such as conveyor devices that otherwise transport textiles from one device to another in a continuous process may not be present in at least some of the equipment in the system used for batch processing.

[0034] In an embodiment of the present disclosure, a textile is provided and then processed according to the steps described herein. The term "textile" refers to a flexible material comprising a network of fibers and is intended to encompass all forms of textile-based articles, including woven, knitted, and nonwoven textiles. The textile may be in the form of a sheet (fabric) or thin strands (yarn). The textile may be formed by techniques known in the art, including one or more processes of weaving, knitting, crocheting, felting, or braiding strands of fiber-containing material together. An exemplary textile substrate may be provided in the form of a textile roll, providing a continuous sheet of textile that may have a width of more than one meter and a length of up to 100 meters or more. Referring to FIG. 1, the arrangement of the textile roll 10 to be processed with respect to other components of the system is shown.

[0035] The textiles cationized using the cationizing agent and heat treatment according to the method of the present disclosure include natural fibers or derivatives thereof. The natural fibers of the textiles can be obtained from plants such as cotton, hemp, ramie, flax, jute, kapok, coir, and bamboo. The plant fibers can be spun to produce long strands, which can be incorporated into textiles by weaving (interlacing threads), knitting (interlacing yarns), and the like, as is known in the art of weaving. In nonwoven fabrics, the plant-based fibers are not converted into threads or yarns, but rather are directly intermingled with each other or with other fibers to produce the nonwoven fabric.

[0036] Natural fibers in textile materials can include natural polymers such as naturally occurring polysaccharides, such as cellulose or cellulosic materials or chitin, or combinations thereof, or derivatives thereof. The cellulose or cellulosic materials, which may include modified cellulose, as well as chitin and its derivatives, have chemicals that allow them to react with cationizing agents. Cellulose consists of repeating glucopyranose subunits, each displaying three hydroxyl groups. Chitosan consists of repeating glycosamine subunits, each displaying two hydroxyl groups and one amine group. The hydroxyl groups of these polysaccharides are reactive with hydroxide-activated cationizing agents.

[0037] Cellulosic materials also include rayon (viscose) produced from wood pulp and lyocell, a form of rayon (e.g., Tencel™).Textile substrates treated according to the present disclosure may also include cellulose derivatives such as cellulose acetate or imidazolidinone-modified cellulose.

[0038] Textiles can be blends or mixtures of different materials, such as blends of natural and synthetic fibers. Blends include blends of different types of natural fibers, such as wool / cotton blends, silk / cotton blends, and angora / cotton blends. Animal-based materials can include collagen fibers, keratin fibers, fibroin fibers, or mixtures thereof. Other exemplary blends include blends of cellulosic and synthetic fibers, such as cotton / polyester blends, cotton / polyolefin blends, cotton / polyacrylonitrile blends, cotton / polyamide blends (e.g., cotton / nylon blends), and blends of cellulosic and cellulosic derivative fibers, such as cotton / rayon blends.

[0039] If the textile comprises a blend of fibers, it preferably has at least about 5% (by weight) natural fibers such as cotton or their derivatives, and more preferably about 25% (by weight) or more, about 35% (by weight) or more, or about 40% (by weight) or more natural fibers (e.g., cellulose) or their derivatives. Exemplary blends include weight ratios of natural fibers (or their derivatives, e.g., cellulose) to synthetic fibers ranging from about 5:95 to about 95:5, 25:75 to about 25:75, or 40:60 to about 60:40.

[0040] Woven textiles can also be described in terms of textile weight (weight / area), which is often expressed in ounces per square yard or grams per square meter. Textile weight can be affected by the type of fibers in the textile and their properties, the type of weave of the textile, and the finish of the textile. Exemplary textile weights are typically about 50 g / m 2 ~About 1000g / m 2 , or about 100 g / m 2 ~about 750g / m 2 The range is.

[0041] In embodiments, the processes of the present disclosure utilize bleached textiles or further include a process step of bleaching textiles. Bleached textiles may have natural color, odor, and other impurities removed from the textile that are otherwise present when the textile fibers are in their raw (natural) form. Oxidative bleaching is typically performed using oxidative bleaching agents such as hydrogen peroxide, sodium hypochlorite, sodium chlorite, sulfuric acid, or combinations thereof. Sodium hydrosulfite is often used in reductive bleaching of textiles.

[0042] If an optional bleaching step is performed, the textile can be placed in a bleach bath for treatment with a bleaching solution for a desired period of time. Exemplary bleaching solutions include hydrogen peroxide or sodium hypochlorite in aqueous solution at concentrations ranging from about 0.5 to 5.0% (by weight). After bleaching, the textile can be washed and dried.

[0043] The method of the present disclosure involves treating a textile with an aqueous treatment solution comprising an alkali metal hydroxide (base) and a cationizing agent.

[0044] Treatment of textiles with a solution containing a base and a cationizing agent can be referred to as a "padding" process, in which an aqueous solution containing a treating compound (treatment solution or padding solution) is placed in contact with the textile. Often, the treatment solution is present in a container (e.g., a "padding bath" or simply a "padder") in which the textile is immersed. In the padding bath, the textile can become saturated with the treatment solution. The base and cationizing agent contact the material of the textile (and in a subsequent process step, the activated cationizing agent reacts with the textile in the presence of heat). Alternatively, the aqueous treatment solution can be applied using a spray device, roller, or brush. Generally, padding is performed for a short period of time, such as one minute or less.

[0045] Cationizing agent, as used herein, refers to a compound that can associate with a textile material, such as by a chemical reaction that results in a covalent bond between the agent and the material of the textile. The reaction imparts a positive (cationic) charge to the textile material.

[0046] Cationizing agents for use in the methods and systems of the present disclosure include mono- and di-quaternized nitrogen compounds. The mono- and di-quaternized nitrogen compounds may include halogenated and hydroxylated ammonium compounds. In the presence of a base, the compounds can be dehalogenated and deprotonated to form reactive glycidyl (epoxy) intermediate compounds, which in turn can react with hydroxyl groups of cellulosic materials in textiles. Amine groups on chitosan-containing textiles can also be reacted with glycidyl-containing ammonium compounds to provide cationization to the textiles.

[0047] One class of cationizing agents are mono-quaternized nitrogen compounds that can generate a single epoxide group in the presence of an alkali metal hydroxide. In some embodiments, the mono-quaternized nitrogen compound is a compound of formula I: [ka] In the formula, R 1 is an alkylene (divalent) group such as a C1-C6 alkylene group such as methylene, ethylene, propylene, etc., and R 2 , R 3 and R 4 are independently selected from alkyl (monovalent) groups, such as C1-C6 alkyl groups such as methyl, ethyl, propyl, and the like, and X and X' are independently halogen atoms, such as Cl, Br, or I. Exemplary compounds of Formula I include 3-chloro-2-hydroxypropyltrimethylammonium chloride (see, e.g., U.S. Pat. No. 5,006,125).

[0048] Another class of cationizing agents are di-quaternized nitrogen compounds that can generate two epoxide groups in the presence of an alkali metal hydroxide. Exemplary cationizing agents include bis-ether dihalogenated dihydroxylated ammonium compounds, such as those of Formula I: [ka] In the formula, R1 and R 1’ are independently selected from alkylene (divalent) groups such as C1-C6 alkylene groups such as methylene, ethylene, propylene, etc., and R 2 , R 2’ , R 3 and R 3’ are independently selected from alkyl (monovalent) groups such as C1-C6 alkyl groups such as methyl, ethyl, propyl, etc., and R 4 and R 4’ are independently selected from alkylene (divalent) groups such as C1-C6 alkylene, and X to X''' are independently selected from halogen atoms such as Cl, Br, or I.

[0049] In some embodiments, the ammonium halide hydroxylate compound is a bis[(3-chloro-2-hydroxypropyldialkylammonium) alkyl] ether dichloride compound. 1 and R 1’ is methylene, and preferably R 2 , R 2’ , R 3 and R 3’ is independently selected from methyl, ethyl, and propyl; R 4 and R 4’ is preferably methylene, ethylene, or propylene. Exemplary compounds include bis[(3-chloro-2-hydroxypropyldimethylammonium)ethyl]ether dichloride, bis[(3-chloro-2-hydroxypropyl-dimethylammonium)ethyl]ether dichloride, and bis[(3-chloro-2-hydroxypropylmethylethyl-ammonium)propyl]ether dichloride. See, for example, U.S. Patent Application Publication No. 2015 / 0210627.

[0050] In embodiments, the treatment solution contains the desired type and amount of base and cationizing agent to facilitate rapid downstream processing in the heating step described herein. In embodiments, the concentration of the cationizing agent in the aqueous treatment solution is at least about 20 g / L, but preferably not more than 125 g / L. Preferably, the concentration of the cationizing agent in the aqueous treatment solution ranges from about 40 to about 105 g / L, from about 50 to about 95 g / L, or from about 55 to about 85 g / L.

[0051] The concentration of the cationizing agent can also be expressed in terms of molar concentration. The concentration of the cationizing agent in the aqueous treatment solution can be at least about 0.05 molar. Preferably, the concentration of the dihalogenated cationizing agent ranges from about 0.05 molar to about 0.3 molar, from about 0.1 molar to about 0.25 molar, from about 0.125 molar to about 0.225 molar, or from about 0.14 molar to about 0.2 molar.

[0052] Exemplary alkali metal hydroxide bases are potassium hydroxide and sodium hydroxide. The amount of base used can be determined by the type and amount of cationizing agent and the heat treatment time and temperature. In embodiments, the concentration of base in the aqueous treatment solution is at least about 10 g / L, but preferably not more than 60 g / L, or not more than 55 g / L. Exemplary concentrations of base in the aqueous treatment solution range from about 15 g / L to about 60 g / L, or from about 20 g / L to about 55 g / L. Expressed in molar terms, the concentration of base in the aqueous treatment solution can be at least about 0.25 molar, or at least about 0.35 molar, but preferably not more than 1.5 molar, or not more than 1.375 molar. Exemplary concentrations of base range from about 0.25 molar to about 1.5 molar, or from about 0.35 molar to about 1.375 molar. Mono-quaternized cationizing agents may use more base than di-quaternized cationizing agents.

[0053] The amounts of base and cationizing agent in the treatment solution may also be described with reference to the molar ratio of base to cationizing agent. In embodiments, the aqueous solution has a molar ratio of alkali metal hydroxide to cationizing agent of 3.5:1 or greater, or 8.0:1 or less, such as in the range of 3.5:1 to 8.0:1, or 3.75:1 to 7.5:1. In other embodiments, the solution has a molar ratio of alkali metal hydroxide to cationizing agent of greater than 1:1, such as in the range of 1.8:1 to 5:1, or 2.0:1 to 4.5:1.

[0054] In some embodiments, the aqueous treatment solution further comprises a thickener (also referred to as a "migration inhibitor"). According to the present disclosure, the use of a thickener can improve immobilization of the cationizing agent in the padded textile, which in turn improves reaction efficiency and subsequently improves the subsequent dyeing of the cationized textile. Exemplary thickeners include polyvinyl methyl ether (e.g., having an average molecular weight of about 100,000), sodium alginate, Gaur gum, carboxymethylcellulose (CMC), low molecular weight cellulose ethers, polyethylene glycol (e.g., having an average molecular weight in the range of 8,000 to 10,000), polyvinyl caprolactam, and acrylic polymers, with acrylic polymers being preferred thickeners. Preferred thickeners should not interfere with dyes, not cause loss of color clarity, have sufficient liquid stability, not cause any handling difficulties, have good solubility at room temperature, and provide good effectiveness in small amounts. In embodiments, a thickening agent is provided in the padding bath to provide a viscosity in the range of about 50 to about 350 cP. In exemplary embodiments, the thickening agent may be used in an amount ranging from about 2% to about 20% by weight, or from about 5% to about 10% by weight in the aqueous padding solution.

[0055] The aqueous padding solution is generally maintained at a temperature of not more than 35°C. Preferably, the aqueous padding solution is at a temperature in the range of about 15°C to about 27°C, or about 18°C ​​to about 25°C.

[0056] In some implementations, the method is a continuous process, in which the textile is fed into a treatment bath, moved through the bath, and then exits the bath. In embodiments, the padding step can be performed rapidly. Referring to FIG. 1 , a sheet of textile 12 advances from a textile roll 10 into a padding bath 20 holding a treatment solution 22 containing a cationizing agent and a base. The padding bath 20 includes a set of rollers (24a-24c) to facilitate movement and positioning of the advancing textile sheet in the treatment solution 22. The residence time in the padding bath ("padding time") is defined by the time a particular portion of the textile enters the bath and then ends when a particular portion exits the padding bath. Typically, this is greater than 0.5 seconds, greater than 1 second, or greater than 2 seconds, and generally less than 1 minute, about 45 seconds or less, or about 30 seconds or less. Exemplary padding times range from 1 second to 1 minute, 1 second to 45 seconds, 1 second to 30 seconds, 1 second to 20 seconds, 1 second to 15 seconds, 1 second to 10 seconds, or 2 seconds to 5 seconds.

[0057] In embodiments, the residence time of the textile in the padding bath can be determined by the machine speed as well as other aspects of the system. For example, the residence time of the textile in the processing area can be known based on the speed at which the system's textile conveyor apparatus moves the textile through the processing area and the length of the path of movement through the processing area. In an exemplary system, the textile conveyor apparatus moves the textile through at least the padding bath at a speed ranging from about 20 meters / minute to about 50 meters / minute. Exemplary lengths of the path of movement through the padding bath can range from about 0.5 meters to about 5 meters, or from about 1 meter to about 4 meters.

[0058] The padding process can result in the textile becoming "soaked" or "saturated" with the treatment solution. In some implementations, as the textile exits the bath, excess treatment solution can be removed from the textile and returned to the padding bath. Referring to FIG. 1 , the textile advances from the treatment bath 22 through a pair of rollers (26 a, 26 b), which apply pressure to the padded textile to remove excess treatment solution, which is returned to the padding bath 20. However, enough treatment solution is maintained in the textile to provide a certain amount of base and cationizing agent to react with the textile in a subsequent heat treatment step.

[0059] Padded textiles may be described in terms of the amount of aqueous treatment solution present in the textile ("effective concentration"). For example, padded textiles may be referred to in terms of "wet pick-up," which is the amount (by weight) of treatment solution present in the textile divided by the weight of the dry textile before padding. Generally, the padding step provides a wet pick-up of treatment solution greater than about 50%. Preferably, the padding step provides a wet pick-up of treatment solution in the range of about 60% to about 80%. In an exemplary scenario, if 100 g / L of cationizing agent is present in the padding bath and there is a 70% wet pick-up, the effective concentration of cationizing agent in the textile is 70 g / L or 7%.

[0060] Generally, the padding process and removal of any excess treatment solution from the saturated textile can be carried out fairly quickly, which facilitates the overall process of cationization and dyeing of the textile.

[0061] After padding the textile, it is introduced into an apparatus that heats the solution-containing textile to promote reaction and bonding of the cationizing agent to the textile material. Referring to FIG. 1, the textile sheet 12 advances from a pair of rollers (26a, 26b) through an opening 32 into a heating apparatus 30. The heating apparatus 30 includes a set of rollers (34a-34e) along which the textile can be supported and moved through a heating chamber. The chamber may have a heating element (not shown) to maintain an atmosphere therein at a desired temperature according to the present disclosure. The heat treatment step is carried out for a short period of time within a well-defined temperature range. Heating can be carried out under normal atmospheric conditions; a steam or modified gas environment is not required.

[0062] Under atmospheric conditions, there can be up to about 30 grams of water vapor in a cubic meter volume of air having a temperature of about 35°C, and therefore the heating step of the present disclosure is carried out under atmospheric conditions with less than 30 grams of water vapor in the air.

[0063] Upon introduction into the heat chamber, the padded textile is rapidly heated to the desired temperature set for the device. Typically, the textile is heated to the desired temperature in a short period of time, such as less than 15 seconds or less than 10 seconds. Once the textile reaches the desired temperature, it can be moved through the heat chamber.

[0064] The textile is heated to a temperature in a heat chamber or temperatures ranging from about 90°C to less than about 110°C and then held at this temperature for a period ranging from about 1 minute to about 10 minutes to allow the cationizing agent to react with the textile.

[0065] In embodiments, the textile is heated in a heating chamber to a temperature or temperatures in the range of about 90° C. to about 109° C., about 90° C. to about 108° C., about 90° C. to about 107° C., about 90° C. to about 106° C., about 90° C. to about 105° C., about 90° C. to about 104° C., about 90° C. to about 103° C., about 90° C. to about 102° C., about 90° C. to about 101° C., or about 90° C. to about 100° C. Heating can be carried out at one or more temperatures for any of the periods of time in the aforementioned ranges, ranging from 1 to 10 minutes, about 1 to 9 minutes, about 2 to 9 minutes, about 2 to 8 minutes, about 2 to 7 minutes, about 3 to 8 minutes, about 3 to 7 minutes, about 3 to 6 minutes, or about 4 to 6 minutes.

[0066] In embodiments, the textile is heated to a temperature in a heating chamber or to a plurality of temperatures ranging from about 91° C. to about 109° C., from about 92° C. to about 109° C., from about 93° C. to about 108° C., from about 93° C. to about 107° C., from about 94° C. to about 106° C., or from about 95° C. to about 105° C. Heating can be carried out at one or more temperatures for any of the periods of time in the aforementioned ranges, ranging from 1 to 10 minutes, from about 1 to 9 minutes, from about 2 to 9 minutes, from about 2 to 8 minutes, from about 2 to 7 minutes, from about 3 to 8 minutes, from about 3 to 7 minutes, from about 3 to 6 minutes, or from about 4 to 6 minutes.

[0067] The method may also be described in terms of the total duration for performing the aqueous treating, mechanically removing, and heat treating steps. For example, these steps may be performed for a period of 11 minutes or less, 10 minutes or less, 9 minutes or less, 8 minutes or less, 7 minutes or less, or 6 minutes or less, or for a period ranging from 1 minute to 11 minutes, 1 minute to 10 minutes, 1 minute to 9 minutes, 1 minute to 8 minutes, 1 minute to 7 minutes, or 1 minute to 6 minutes.

[0068] The heat treatment temperatures and times of the present disclosure can promote rapid reaction of the cationizing agent with reactive chemicals while minimizing hydrolysis of the cationizing agent, which would otherwise render the cationizing agent non-functional.

[0069] Optionally, the treated textile can be described in terms of the reaction efficiency of the cationizing agent with the textile. The reaction efficiency can be expressed in terms of the amount of cationizing agent reacted per unit of textile weight (e.g., mmol of cationizing agent per gram of textile material). The reaction efficiency (degree of cationization) can be determined by the amount of nitrogen content of the textile as imparted by the cationizing agent. For example, the process of the present disclosure provides at least about 0.075 mmol of nitrogen (from the cationizing agent) per gram of textile. More typically, there is at least about 0.085 mmol, at least about 0.09 mmol, or at least about 0.095 mmol of nitrogen (from the cationizing agent) per gram of textile. The reaction of the cationizing agent can be determined by analyzing the added ammonium groups to the textile, such as by Kjeldahl or combustion methods (see, for example, Schwarzinger, C., et al. (2002) Monatshefte fur Chemie 133:1-17, or Ma, W., et al. (2017) Molecules, 22:2235).

[0070] After the cationized textile is heat-treated, it may be washed with a hot aqueous solution. The hot water wash may remove at least a portion of any unreacted or hydrolyzed cationizing agent, base, and / or other optional components (e.g., thickeners) carried over from the padding bath. For example, in a continuous process, the heat-treated textile may exit the heating device 30 through opening 36 and be fed to a hot water bath 40. The hot water bath 40 includes a set of rollers (44a-44e) to facilitate movement and positioning of the advancing textile sheet in the hot water.

[0071] The hot aqueous solution may have a pH in the range of 6 to 8. The temperature of the hot water bath is preferably in the range of about 70°C to about 90°C, or even more preferably in the range of about 75°C to about 85°C. The cationized textile may be maintained in the hot water bath for a period of less than 20 minutes, less than 15 minutes, such as a period of about 5 to 15 minutes. In a continuous process, the textile may be moved through the bath, such as on rollers in the bath, and then the textile may exit the bath after the desired washing period. The washed textile may be transferred to a neutralization bath without removing water from the textile.

[0072] After the cationized textile has been hot water washed, it can be neutralized by treatment with an acid. The acid can react with any remaining base present in the textile, thereby neutralizing the cationized textile. For example, in a continuous process, referring to FIG. 1, the washed cationized textile can exit the hot water bath 40, be mechanically treated, such as by passing through a pair of rollers (not shown) to remove the hot aqueous solution, and then be fed to a neutralization bath 50 containing an aqueous composition including an acid. The neutralization bath 50 can include a set of rollers (54a-54e) to facilitate movement and positioning of the advancing textile sheet through the bath's acid-containing solution.

[0073] The acid-containing solution can have an exemplary pH in the range of about 4 to about 5. For example, the acid solution can be formed using a weak acid such as acetic acid, citric acid, or oxalic acid, or a combination thereof. The amount of acid can depend on the type of acid used, but an exemplary acid is acetic acid at a concentration in the range of about 1 to about 2 grams per liter. The acid treatment solution is generally maintained at a temperature of 35°C or less. Preferably, the acid treatment solution is at a temperature in the range of about 15°C to about 27°C or about 18°C ​​to about 25°C.

[0074] The cationized textile can be maintained in the acid treatment solution for a period of time less than 20 minutes, less than 15 minutes, such as a period ranging from about 5 to 15 minutes. In a continuous process, the textile can be moved through the acid treatment solution, such as on rollers in a bath, and then the textile can exit the acid treatment solution after a desired washing period. Thus, the dyeing step and dyeing equipment may or may not be part of the methods and systems of the present disclosure.

[0075] The systems and methods of the present disclosure may optionally include one or more steps of cold or hot water washing during the post-neutralization / acid treatment.

[0076] After the cationized textile is neutralized, it can be dyed by treating it in a dye solution. The dyeing process can be carried out using the same system as the padding bath and heat treatment equipment, or it can be carried out in a different system that is separate from the padding bath and heat treatment equipment. If the dyeing process is carried out using a different system, such as in a dyeing facility located in a different location from the facility that has the padding / heat treatment system, the cationized textile can be transported to that facility and dyed.

[0077] For purposes of discussing the steps of dyeing a textile, reference is made to Figure 1, which illustrates a system having a dye bath. For example, in a continuous process, the neutralized cationized textile can exit neutralization bath 50, can be mechanically treated, such as by passing through a pair of rollers (not shown) to remove any excess acid solution, and can then be fed to dye bath 60, which contains a composition having a dye. Dye bath 60 can include roller sets (64a-64e) to facilitate movement and positioning of the advancing textile sheet through the dye solution.

[0078] Cationized textiles can accept a variety of dyes, thus offering good flexibility for color delivery. Cationized textiles can provide improved dye association through chemical interactions between the positively charged quaternized nitrogen of the textile-bound cationic agent and, for example, the anionic group of an anionic dye. However, cationic textiles can also accept other dye types that associate with the textile in a manner independent of the textile-bound cationic agent.

[0079] The "dyeing" process imparts color to textiles, and "dye," as described herein, refers to any substance that provides color to textiles, which may also include pigments. Dyes can associate with textile fibers through chemical reaction, absorption, dispersion, or a combination thereof. Dyes typically differ in their resistance to sunlight, perspiration, washing, gases, and alkalis, their affinity for different fibers, their response to cleaning agents and methods, and their solubility and application methods. Exemplary dye types that can be used to color cationized textiles made using the methods and systems of the present disclosure include natural dyes, basic (cationic) dyes, direct (substantial) dyes, sulfur dyes, pigment dyes, vat dyes, reactive dyes, and acid dyes.

[0080] Reactive dyes can react with one or more chemical groups on textile fibers. They can be applied from alkaline or neutral solutions, which are then alkalized in a separate process. Heat treatments can also be used during dyeing to develop different shades. After dyeing, the textile can be washed with soap to remove any unfixed dye. Reactive dyes can be used on cationic textiles, including cellulose fibers, as well as blends of wool, silk, nylon, and acrylic.

[0081] Direct dyes can be used to color cellulose fibers directly without the need for a mordant (dye fixative). Direct dyes can be used on cationic textiles containing cellulose fibers, as well as blends of wool, silk, nylon, rayon, etc.

[0082] Sulfur dyes are water-insoluble and are made soluble using reducing agents and alkaline pH (e.g., caustic soda and sodium sulfide). Dyeing is done at high temperatures with large amounts of salt to penetrate the color into the fiber. After dyeing, the textile is oxidized by exposure to air or by using chemicals to provide the desired shade. Excess dye and chemicals can be removed by thorough washing. Sulfur dyes are fast to light, washing, and perspiration and are most often used on cotton and linen.

[0083] Vat dyes are insoluble in water and are typically made soluble by reducing alkaline solutions, allowing them to be fixed to textile fibers. Subsequent oxidation or exposure to air restores the dye to its insoluble form. An exemplary vat dye is indigo. Vat dyes are the most fast dyes for cotton, linen, and rayon. Vat dyes are commonly used with mordants to dye other textiles, such as wool, nylon, polyester, acrylic, and modacrylic.

[0084] Although pigments are not strictly dyes, they are still used to color textiles such as cotton, wool, and other man-made fibers due to their excellent lightfastness. Pigments are typically fixed to textile fibers using resins. After dyeing, the textile is exposed to high temperatures. In some embodiments, the dyeing step according to the present disclosure can use pigments to color cationized textiles. Natural dyes obtained from natural sources, such as plant, animal, or mineral sources, can be used with cationized textiles. Direct printing is the most common approach for applying color patterns to textiles. When performed on colored textiles, it is known as overprinting. The desired pattern is created by pressing the dye onto the textile in paste form. To prepare the printing paste, a thickener is added to a limited amount of water and the dye is dissolved therein. Previously, starch was the preferred thickener for printing. More recently, gums or alginates derived from seaweed have become preferred because they allow better color penetration and are easier to clean. Most pigment printing is done without thickeners, as the mixture of resin, solvent and water creates the thickening.

[0085] Some dyes used to dye cationic textiles include "reactive" or anionic dyes. Reactive anionic dyes may contain one or more anionic groups, such as sulfonate or carboxylate groups. For example, anionic dyes may contain one or more sodium sulfonate (-SO3Na) groups. One or more anionic groups may be present in the dye molecule, which can absorb light within the visible spectrum and have at least one chromophore / color-carrying group with a conjugated system. Commonly used anionic dyes include those based on azo chemistry, anthraquinone chemistry, and triphenylmethane chemistry. Azo dyes are chemically characterized by the group RN=N-R', where R and R' generally contain aryl groups with various chemical substituents attached to the aryl group. Other anionic dyes include those with nitro chemistry, azine chemistry, and quinoline chemistry. Acid dyes are a type of anionic dye that may contain an acid group, such as a carboxylic acid group, a sulfonic acid group, or a phosphate group. Anionic dyes that can be used in the methods of the present disclosure are described in various references, such as Aspland, JR, (1997) Textile Dyeing and Coloration, American Association of Textile Chemists and Colorists, AATCC, and Knutson, L. (1986) Synthetic Dyes for Natural Fiber, Interweave Press; Revised edition. Examples include dyes designated "reactive," "direct," and "acid," preceded or followed by the color name and a number and / or letter, such as "reactive blue 19," "direct blue 71," "acid blue 62," and "reactive red ME4BL."

[0086] In some embodiments, the concentration of the anionic dye in the dye solution ranges from about 0.001 g / L to about 5.0 g / L, or from about 0.01 to about 2 g / L, with more concentrated dye solutions providing a stronger dye color to the textile. In embodiments, the anionic dye solution is generally maintained at a temperature ranging from about 30°C to about 80°C. Dyeing may be carried out for a desired period of time, such as from about 30 minutes to about 60 minutes. Referring to FIG. 1, after dyeing, the textile may be washed (not shown) and then wound on roller 72.

[0087] The operation of one or more portions of the system can be controlled using a process controller (not shown), such as a computer-based controller that can be programmed to carry out the processing methods as described herein. [Example]

[0088] Pad-dry cationization and dyeing of cotton fabric Bleached cotton fabric (A4 size) was immersed in various solutions containing the di-quaternized cationizing agent bis[(3-chloro-2-hydroxypropyldimethylammonium)ethyl]ether dichloride (bis-CHPDMAEEDC) (commercially available from Dow under the trade name ECOFAST™ Pure) and sodium hydroxide. The concentrations of bis-CHPDMAEEDC and NaOH base are listed in Table 1.

[0089] The solution was at ambient temperature (20°C), and the fabric was held in the solution for approximately 2-3 seconds before being removed. The soaked fabric was then passed through two rollers at 70% pressure to squeeze excess solution from the fabric. The effective concentration of cationizing agent on the fabric was therefore 49 g / L (0.119 mol). Following this, the fabric was heat-treated at various temperatures: 80°C, 90°C, 100°C, 110°C, and 120°C for various durations: 5 minutes, 10 minutes.

[0090] As a control, the cationizing agent and base (70 gpl bis-CHPDMAEEDC and 20 gpl NaOH) were padded onto an A4 cotton cloth and then placed at low temperature (25° C.) for a period of 14 hours to allow the batch reaction.

[0091] After the heat treatment, the cationized fabric was washed in hot water at a temperature of 80°C for 10 minutes, and then the washed fabric was neutralized in a solution containing acetic acid (1 / 5 g / L) per NaOH concentration at ambient conditions (temperature 30°C) for 10 minutes. After cationization, the nitrogen content on the fabric was evaluated by a combustion method.

[0092] Dyeing was carried out by placing 2 gm of cationized cotton in a dye composition containing 3% Reactofix Red ME4BL dye solution and 15 g / L sodium carbonate to improve fixation and performance properties. The dye solution was at a temperature of 60°C, and the fabric was kept in the solution for 30 minutes. This was followed by a washing process of cold washing and neutralization, a hot wash at 60°C for 10 minutes, and then a cold wash. The results of the rapid heat treatment were compared and normalized against a cotton fabric prepared as a control.

[0093] [Table 1]

[0094] Heat treatments at temperatures below 110°C were found to provide better dyeing, and these lower temperatures were investigated using various durations of heat treatment in Example 2. [Example]

[0095] Rapid pad-dry cationization and dyeing of cotton fabrics Pad-drying treatments of bleached cotton fabric (A4 size) were carried out according to Example 1, but for various periods of time at different temperatures using the mono-quaternized cationizing agent 3-chloro-2-hydroxypropyltrimethylammonium chloride (CHPTMAC, commercially available from Dow under the trade name Ecofast CR 2000), and the di-quaternized compound bis-CHPDMAEEDC. The concentrations of CHPTMAC, bis-CHPDMAEEDC, and NaOH base are listed in Table 2.

[0096] After cationization, the nitrogen content on the fabric was assessed and dyeing was carried out using the dyeing process described in Example 1. The results were compared to the "cold pad batch" positive control described in Example 1.

[0097] [Table 2]

[0098] The fabric dyeing results revealed that fabric samples treated with bis-CHPDMAEEDC and CHPTMAC at temperatures of 90°C or 100°C and for periods of 5 or 10 minutes provided better results than the comparative temperatures and times, with a treatment time of 5 minutes at 90°C or 100°C providing the best results.

[0099] The nitrogen content on cationic cotton resulting from treatment with bis-CHPDMAEEDC at different conditions was measured and is shown in Table 3 and Figure 2. The nitrogen content on cationic cotton resulting from treatment with CHPTMAC at different conditions was measured and is shown in Table 4 and Figure 3. Again, temperatures of 90°C or 100°C and periods of 5 or 10 minutes provided better results than comparative temperatures and times, with a 5 minute treatment time at 90°C or 100°C providing the best results.

[0100] [Table 3]

[0101] [Table 4] The present invention can provide the following aspects. [1] 1. A method for cationizing a textile comprising natural fibers or derivatives thereof, comprising: treating the textile with an aqueous solution containing an alkali metal hydroxide and a mono- or di-quaternized cationizing agent; and heating the textile at a temperature ranging from 90°C to less than 110°C for a period ranging from 1 minute to 10 minutes to react the cationizing agent with the textile. [2] The method according to [1] above, wherein the cationizing agent is a mono-quaternized nitrogen compound capable of generating a single epoxide group in the presence of an alkali metal hydroxide. [3] wherein the mono-quaternized nitrogen is a compound of formula I,

change

change

[10] The method according to [9] above, wherein the cationizing agent is bis[(3-chloro-2-hydroxypropyldialkylammonium)alkyl]ether dichloride.

[11] The method according to any one of the above [1] to

[10] , wherein the molar ratio of the alkali metal hydroxide to the cationizing agent is 3.5:1 or more, or 8.0:1 or less.

[12] The method according to

[11] above, wherein the molar ratio of the alkali metal hydroxide to the cationizing agent is within the range of 3.5:1 to 8.0:1, or 3.75:1 to 7.5:1.

[13] The method according to any one of the above [1] to

[12] , wherein the aqueous solution further contains a thickener.

[14] The method according to any one of the above [1] to

[13] , wherein the textile is treated at a temperature in the range of 90°C to 109°C, 90°C to 108°C, 90°C to 107°C, 90°C to 106°C, 90°C to 105°C, 90°C to 104°C, 90°C to 103°C, 90°C to 102°C, 90°C to 101°C, or 90°C to 100°C.

[15] The method according to any one of the above [1] to

[13] , wherein the textile is treated at a temperature in the range of 91°C to 109°C, 92°C to 109°C, 93°C to 108°C, 93°C to 107°C, 94°C to 106°C, or 95°C to 105°C.

[16] The method according to any one of the above [1] to

[15] , wherein the textile is treated in heat for a period of time ranging from 1 to 10 minutes, about 1 to 9 minutes, about 2 to 9 minutes, about 2 to 8 minutes, about 2 to 7 minutes, about 3 to 8 minutes, about 3 to 7 minutes, about 3 to 6 minutes, or about 4 to 6 minutes.

[17] The method according to any one of the above [1] to

[16] , comprising mechanically removing a portion of the aqueous solution from the fabric after the treatment with the aqueous solution.

[18] 18. The method of claim 17, wherein the aqueous treatment step and the mechanical removal step are carried out at one or more temperatures below 35°C and for a total time period of 1 minute or less.

[19] The method according to

[18] above, wherein the aqueous treatment step and the mechanical removal step are carried out for a total period of time in the range of 45 seconds or less, 30 seconds or less, 1 second to 1 minute, 1 second to 45 seconds, 1 second to 30 seconds, 1 second to 20 seconds, 1 second to 15 seconds, 1 second to 10 seconds, or 2 seconds to 5 seconds.

[20] The method according to any one of

[17] to

[19] above, wherein the total period for carrying out the aqueous treatment step, the mechanical removal step, and the thermal treatment step is a fixed period of 11 minutes or less, 10 minutes or less, 9 minutes or less, 8 minutes or less, 7 minutes or less, or 6 minutes or less, or a fixed period in the range of 1 minute to 11 minutes, 1 minute to 10 minutes, 1 minute to 9 minutes, 1 minute to 8 minutes, 1 minute to 7 minutes, or 1 minute to 6 minutes.

[21] The method according to any one of the above [1] to

[20] , further comprising neutralizing the fabric in an acid-containing solution after the heat treatment.

[22] The method according to any one of [1] to

[21] above, further comprising dyeing the fabric with a composition containing a dye.

[23] 1. A system for cationizing and dyeing textiles comprising natural fibers or derivatives thereof, comprising: a padding bath for treating textiles comprising natural fibers or derivatives thereof, the padding bath being configured to hold an aqueous solution comprising an alkali metal hydroxide and a cationizing agent comprising a halogenated compound capable of generating two epoxide groups in the presence of the alkali metal hydroxide; a heating device capable of treating the textile at a temperature ranging from 90°C to less than 110°C for a period ranging from 1 minute to 10 minutes to react the cationizing agent with the textile.

[24] below: a roller mechanism for mechanically removing a portion of the aqueous solution from the fabric; and a neutralization bath for neutralizing the fabric in an acid-containing solution.

[25] The system of any one of claims 23 to 24, further comprising a process controller that enables the treatment with the aqueous solution and the mechanical removal at one or more temperatures below 35°C and for a total period of time of 1 minute or less.

Claims

1. 1. A method for cationizing a textile comprising natural fibers or derivatives thereof, comprising: treating the textile with an aqueous solution comprising an alkali metal hydroxide and a mono-quaternized cationizing agent; heating the textile at a temperature ranging from 90°C to less than 110°C for a period ranging from 1 minute to 10 minutes to react the cationizing agent with the textile; the cationizing agent is a mono-quaternized nitrogen compound capable of generating a single epoxide group in the presence of an alkali metal hydroxide; wherein the mono-quaternized nitrogen is a compound of formula I, 【Chemical 1】 wherein R 1 is a C1 to C6 alkylene group; R 2 , R 3 and R 4 are independently selected from C1 to C6 alkyl groups; X and X′ are independently selected from halogen atoms; the concentration of the cationizing agent in the aqueous solution is in the range of 40 to 105 g / L; the molar ratio of said alkali metal hydroxide to said cationizing agent is from 3.5:1 to 8.0:

1.

2. 2. The method of claim 1, wherein the mono-quaternized compound is 3-chloro-2-hydroxypropyltrimethylammonium chloride.

3. A method for cationizing a textile comprising natural fibers or derivatives thereof, comprising: treating the textile with an aqueous solution comprising an alkali metal hydroxide and a di-quaternized cationizing agent; heating the textile at a temperature ranging from 90°C to less than 110°C for a period ranging from 1 minute to 10 minutes to react the cationizing agent with the textile; the cationizing agent is a di-quaternized nitrogen compound capable of generating two epoxide groups in the presence of an alkali metal hydroxide; the cationizing agent is a bis-ether halogenated di-hydroxylated di-quaternized ammonium compound; The cationizing agent has the formula: 【Chemistry 2】 wherein R 1 and R 1' are independently selected from C1 to C6 alkylene groups; R 2 , R 2' , R 3 and R 3' are independently selected from C1 to C6 alkyl groups; R 4 and R 4' are independently selected from C1 to C6 alkylene groups; and X to X''' are independently selected from halogen atoms; the concentration of the cationizing agent is in the range of 0.1 mol / L to 0.25 mol / L; the molar ratio of said alkali metal hydroxide to said cationizing agent is greater than or equal to 2.65:1 and less than or equal to 8.0:

1.

4. 4. The method of claim 3, wherein the cationizing agent is bis[(3-chloro-2-hydroxypropyldialkylammonium)alkyl]ether dichloride.

5. 5. The method of claim 1, further comprising the step of mechanically removing a portion of the aqueous solution from the fabric after treating with the aqueous solution, wherein the steps of treating with the aqueous solution and mechanically removing are carried out at one or more temperatures below 35°C and for a total period of time of 1 minute or less.

Images