Pad-steam cationization of textiles

Abstract

Described are methods and systems for cationizing and dyeing a natural fiber-containing textile. The method includes a step of steam treating a textile padded with a base and cationizing agent in a defined temperature range (greater than 100° C. to less than 110° C.) and for a defined time period (1 min to 10 min). The cationizing agent in the presence of the base is capable of generating two epoxide groups. The cationization step in the presence of steam using the halogenated catonization agent of the invention facilitates improved dyeing.

1 . A method for cationizing a textile including a natural fiber or derivative thereof, the method comprising
 treating a textile including a natural fiber or derivative thereof with 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; and   treating the textile in an environment comprising steam at a temperature in the range of greater than 100° C. to less than 110° C. for a period of time in the range of 1 min to 10 min to react the cationizing agent with the fabric.   
     
     
         2 . The method of  claim 1 , wherein the cationizing agent is a bis ether halogenated di-hydroxylated ammonium compound. 
     
     
         3 . The method of  claim 2  wherein the cationizing agent has the formula: 
       
         
           
           
               
               
           
         
         wherein R 1  and R 1′  are independently selected from alkylene groups, R 2 , R 2′ , R 3 , and R 3′ , are independently selected from alkyl groups, R 4  and R 4′  are independently selected from alkylene groups, such as a C1-C6 alkylene, and X-X′″ are independently selected from halogen atoms. 
       
     
     
         4 . The method of  claim 3  wherein R 1  and R 1′  are independently selected methylene, ethylene, and propylene, R 2 , R 2′ , R 3 , and R 3′ , are independently selected from methyl, ethyl, and propyl, and R 4  and R 4′  are independently selected from C1-C6 alkylene. 
     
     
         5 . The method of  claim 4  wherein the cationizing agent is bis[(3-chloro-2-hydroxypropyl-dialkylammonium)alkyl]ether dichloride. 
     
     
         6 . The method of  claim 1  wherein the textile is treated in steam at a temperature in the range of greater than 100° C. to less than 107° C., greater than 100° C. to less than 106° C., greater than 100° C. to less than 105° C., greater than 100° C. to less than 104° C., or in the range of greater than 100° C. to less than 103° C. 
     
     
         7 . The method of  claim 1  wherein the textile is treated in steam for a period of time in the range of 1 to 10 minutes, about 1 to 9 minutes, about 2 to 8 minutes, about 2 to 7 minutes, about 3 to 7 minutes, about 3 to 6 minutes, or about 4 to 6 minutes. 
     
     
         8 . The method of  claim 1  comprising mechanically removing a portion of the aqueous solution from the fabric after treating with the aqueous solution. 
     
     
         9 . The method of  claim 8  wherein the steps of treating with aqueous solution and mechanically removing are performed at one or more temperatures of less than 35° C., and for a total a period of time of not greater than 1 minute. 
     
     
         10 . The method of  claim 9  wherein the wherein the steps of treating with aqueous solution and mechanically removing are performed for a total a period of time of not more than seconds, not more than 30 seconds, in the range of 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. 
     
     
         11 . The method of  claim 8  wherein the wherein the steps of treating with aqueous solution, mechanically removing, and treating the fabric in an environment comprising steam are performed for a total a period of time of not more than 11 minutes, not more than 10 minutes, not more than 9 minutes, not more than 8 minutes, not more than 7 minutes, or not more than 6 minutes, or for a period of time 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. 
     
     
         12 . The method of  claim 1  wherein the aqueous solution has a molar ratio of the alkali metal hydroxide to the cationizing agent of greater than 1:1. 
     
     
         13 . The method of  claim 12  wherein the molar ratio of the alkali metal hydroxide to the cationizing agent is in the range of 1.8:1 to 5:1, or 2.0:1 to 4.5:1. 
     
     
         14 . The method of  claim 1 , wherein the aqueous solution further comprises a viscosity enhancer. 
     
     
         15 . The method of  claim 1  further comprising neutralizing the fabric in an acid-containing solution following treating with steam. 
     
     
         16 . The method of  claim 1 , further comprising dyeing the fabric with a composition comprising a dye. 
     
     
         17 . A system for cationizing and dyeing a textile including a natural fiber or derivative thereof, the method comprising
 a padding bath for treating a textile including a natural fiber or derivative thereof 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; and   a steaming apparatus capable of treating the fabric in an environment comprising steam at a temperature in the range of greater than 100° C. to less than 110° C. for a period of time in the range of 1 min to 10 min to react the cationizing agent with the fabric.   
     
     
         18 . The system of  claim 17  further comprising one or more of the following:
 a roller mechanism for mechanically removing a portion of the aqueous solution from the fabric; 
 a neutralization bath for neutralizing the fabric in an acid-containing solution. 
 
     
     
         19 . The system of  claim 17  further comprising process controller allowing for the treatment with the aqueous solution and the mechanical removal at one or more temperatures of less than 35° C., and for a total a period of time of not greater than 1 minute.