Polyamide fiber with enhanced dyeing properties, process for obtaining such fiber and polyamide article made therefrom

Abstract

The present invention relates to a polyamide fiber with enhanced dyeing properties. The polyamide fiber is suitable for low-temperature dyeing and shorter dyeing cycle. The present invention also discloses a method for obtaining such a fiber. The polyamide fiber is obtained by blending at least a polyamide 5.X, X being an integer from 4 to 16 with an aliphatic polyamide during the melt-spinning extrusion of the polyamide fiber. The blended polyamide fiber and articles made therefrom can be dyed at a lower temperature than the usual boiling temperature, and the dyeing time is half of the time of a normal dyeing cycle. The dyed polyamide fiber and article also show enhanced fastness to washing and perspiration.

1 . A polyamide fiber with enhanced dyeing properties, comprising a blend of at least:
 a first polyamide selected from the group consisting of polyamide 6, polyamide 6.6, polyamide 6.9, polyamide 6.12, polyamide 6.10, polyamide 11, polyamide 12, polyamide 10.10, polyamide 4.6, polyamide 4.10, polyamide 12.12, polyamide 10.12, and mixtures thereof, and   a second polyamide selected from polyamides 5.X, wherein X is an integer from 4 to 16, and mixtures thereof.   
     
     
         2 . A polyamide fiber according to  claim 1 , wherein the first polyamide is selected from the group consisting of polyamide 6.6, polyamide 6, and mixtures thereof. 
     
     
         3 . A polyamide fiber according to  claim 1 , wherein the second polyamide is polyamide 5.6. 
     
     
         4 . A polyamide fiber according to  claim 1 , wherein the second polyamide is present in an amount of about 1.0% to 40.0% by weight of the total weight of the polyamide fiber. 
     
     
         5 . A method for obtaining making a polyamide fiber according to  claim 1 , comprising melt-spinning extrusion of a blend of at least the first and the second polyamide  4 . 
     
     
         6 . A method according to  claim 5 , wherein the melt-spinning extrusion comprises the following steps:
 a1. feeding the first polyamide melt, pellet, or powder into the inlet of a screw extruder or grid spinning head,   a2. melting, homogenizing, and pressurizing the polyamide,   a3. spinning the molten polyamide into a fiber, and   a4. cooling down and winding the fiber;   
       wherein the second polyamide is continuously introduced during step al as a pellet or powder form. 
     
     
         7 . A method according to  claim 5 , wherein the melt-spinning extrusion comprises the following steps:
 a0. polymerizing diacid and diamine monomers or salts thereof to form a blend of at least the first and the second polyamides,   a′1. feeding the blend of at least the first and the second polyamides as a melt, as pellets or as a powder into the inlet of a screw extruder or grid spinning head,   a2. melting, homogenizing, and pressurizing the polyamide,   a3. spinning the molten polyamide into a fiber,   a4. cooling down and winding the fiber.   
     
     
         8 . A method according to  claim 5 , wherein the melt-spinning extrusion comprises the following steps:
 a1. feeding the first polyamide melt, pellet or powder into the inlet of a screw extruder or grid spinning head,   a2. melting, homogenizing, and pressurizing the polyamide,   a3. spinning the molten polyamide into a fiber,   a4. cooling down the fiber and winding the fiber,   
       wherein the second polyamide is continuously introduced during step a3 as a polyamide melt. 
     
     
         9 . A method according to  claim 5 , wherein the second polyamide is present in an amount of 1.0% to 40.0% 5.0 to 20.0% by weight of the total weight of the polyamide fiber. 
     
     
         10 . A method according to  claim 5 , wherein the resulting polyamide fiber is dyed. 
     
     
         11 . A method according to  claim 10 , wherein the polyamide fiber is dyed at a temperature from 40° C. to 80° C. 
     
     
         12 . A method according to  claim 10 , wherein the polyamide fiber is dyed with a dyeing cycle of from 20 to 40 minutes. 
     
     
         13 . A polyamide article comprising a polyamide fiber according to  claim 1 . 
     
     
         14 . A polyamide article according to  claim 13 , wherein the polyamide article is a fiber, a staple fiber, a flock, a woven, a knitted or non-woven fabric, or a textile article. 
     
     
         15 . A method according to  claim 13 , wherein the polyamide fiber is transformed by texturizing, drawing, warping, knitting, weaving, nonwoven processing, garment manufacturing or a combination thereof. 
     
     
         16 . A method to  claim 13 , wherein the polyamide article is dyed. 
     
     
         17 . A method according to  claim 15 , wherein the polyamide article is dyed at a temperature from 40° C. to 80° C. 
     
     
         18 . A method according to  claim 16 , wherein the polyamide article is dyed with a dyeing cycle of from 20 to 40 minutes. 
     
     
         19 . A method for enhancing the dyeing properties of a polyamide fiber, comprising blending a second polyamide selected from 5.X, wherein X is an integer of from 4 to 16, and mixtures thereof with at least a first polyamide selected from the group consisting of polyamide 6, polyamide 6.6, polyamide 6.9, polyamide 6.12, polyamide 6.10, polyamide 11, polyamide 12, polyamide 10.10, polyamide 4.6 polyamide 4.10, polyamide 12.12, polyamide 10.12, and mixtures thereof in order to enhance the dyeing properties of a polyamide fiber made therefrom. 
     
     
         20 . A polyamide fiber according to  claim 4 , wherein the second polyamide is present in an amount of about 5.0 to 20.0% by weight of the total weight of the polyamide fiber. 
     
     
         21 . A polyamide fiber according to  claim 1 , wherein the polyamide fiber has an overall dtex of about 40 to 300, and a dtex per filament of about 1 to 5. 
     
     
         22 . A method according to  claim 10 , wherein the resulting polyamide fiber is dyed with an acid dye. 
     
     
         23 . A method according to  claim 16 , wherein the polyamide article is dyed with an acid dye.