Soluble microfilament-generating multicomponent fibers

Abstract

Microfilament-generating multicomponent fibers are provided that include a first polymer component and a second polymer component extruded together in separate contiguous polymer segments extending along the length of the fiber. The first polymer component comprises a synthetic melt-processable polymer that is substantially soluble in a first relatively benign solvent selected from water, aqueous caustic solution, and non-halogenated organic solvents. The second polymer component is formed from a second synthetic melt-processable polymer dimensioned to produce one or more microfilaments upon dissolution of the first polymer, and that is substantially soluble in an aqueous solvent selected from water and aqueous caustic solution. The two polymer components are dissolvable in different solvents.

1 . A microfilament-generating multicomponent fiber, comprising: 
 a first polymer component and a second polymer component extruded together in separate contiguous polymer segments extending along the length of the fiber;    wherein said first polymer component comprises a first synthetic melt-processable polymer, the first synthetic melt-processable polymer being substantially soluble in a first solvent selected from the group consisting of water at a temperature of 70° C. or above, water at a temperature of less than 70° C., aqueous caustic solution, and a non-halogenated organic solvent; and    wherein said second polymer component comprises a second synthetic melt-processable polymer, at least a portion of said second polymer component being dimensioned to produce one or more microfilaments upon dissolution of said first polymer, the second synthetic melt-processable polymer being substantially soluble in a second aqueous solvent selected from the group consisting of water at a temperature of 70° C. or above, water at a temperature of less than 70° C., and aqueous caustic solution;    wherein said first solvent and said second solvent are different such that said second polymer is not dissolvable in said first solvent.    
   
   
       2 . The multicomponent fiber of  claim 1 , wherein the first solvent is water at a temperature of less than 70° C. and the second aqueous solvent is water at a temperature of 70° C. or above.  
   
   
       3 . The multicomponent fiber of  claim 1 , wherein the first solvent is water at a temperature of less than 70° C. and the second aqueous solvent is aqueous caustic solution.  
   
   
       4 . The multicomponent fiber of  claim 1 , wherein the first solvent is water at a temperature of 70° C. or above and the second aqueous solvent is aqueous caustic solution.  
   
   
       5 . The multicomponent fiber of  claim 1 , wherein the first solvent is a non-halogenated organic solvent and the second aqueous solvent is water at a temperature of less than 70° C.  
   
   
       6 . The multicomponent fiber of  claim 1 , wherein the first solvent is a non-halogenated organic solvent and the second aqueous solvent is water at a temperature of 70° C. or above.  
   
   
       7 . The multicomponent fiber of  claim 1 , wherein the first solvent is a non-halogenated organic solvent and the second aqueous solvent is aqueous caustic solution.  
   
   
       8 . The multicomponent fiber of  claim 1 , wherein the first solvent is aqueous caustic solution and the second aqueous solvent is water at a temperature of 70° C. or above.  
   
   
       9 . The multicomponent fiber of  claim 1 , wherein said first polymer component is selected from the group consisting of sulfonated polyesters, sulfonated polystyrene, ethylene vinyl alcohol, polyvinyl alcohol, polyethylene oxide, polyglycolic acid, polylactic acid, polycaprolactone, and polystyrene.  
   
   
       10 . The multicomponent fiber of  claim 1 , wherein said second polymer component is selected from the group consisting of sulfonated polyesters, sulfonated polystyrene, ethylene vinyl alcohol, polyvinyl alcohol, polyethylene oxide, polyglycolic acid, polylactic acid, and polycaprolactone.  
   
   
       11 . The multicomponent fiber of  claim 1 , wherein said first polymer component is polyvinyl alcohol or a sulfonated polyester and said second polymer component is polylactic acid.  
   
   
       12 . The multicomponent fiber of  claim 1 , wherein said first polymer component is polystyrene and said second polymer component is selected from the group consisting of sulfonated polyesters, sulfonated polystyrene, ethylene vinyl alcohol, polyvinyl alcohol, polyethylene oxide, polyglycolic acid, polylactic acid, and polycaprolactone.  
   
   
       13 . The multicomponent fiber of  claim 1 , wherein said one or more microfilaments have a fineness of less than about 1.5 denier.  
   
   
       14 . The multicomponent fiber of  claim 13 , wherein said one or more microfilaments have a fineness of less than about 1.0 denier.  
   
   
       15 . The multicomponent fiber of  claim 14 , wherein said one or more microfilaments have a fineness of less than about 0.5 denier.  
   
   
       16 . The multicomponent fiber of  claim 15 , wherein said one or more microfilaments have a fineness of less than about 0.2 denier.  
   
   
       17 . The multicomponent fiber of  claim 16 , wherein said one or more microfilaments have a fineness of about 0.01 to about 0.2 denier.  
   
   
       18 . The multicomponent fiber of  claim 1 , wherein the fiber is selected from the group consisting of continuous filament, tow, staple fiber, spunbond fiber, and meltblown fiber.  
   
   
       19 . The multicomponent fiber of  claim 1 , wherein the fiber has a cross-sectional configuration selected from the group consisting of pie/wedge, segmented round, segmented oval, segmented ribbon, segmented multi-lobal, segmented cross, and islands-in-the-sea.  
   
   
       20 . The multicomponent fiber of  claim 19 , wherein the fiber has a pie/wedge cross-sectional configuration.  
   
   
       21 . The multicomponent fiber of  claim 19 , wherein the fiber has an islands-in-the-sea cross-sectional configuration.  
   
   
       22 . A fiber bundle comprising a plurality of microfilaments generated from one or more multicomponent fibers of  claim 1 .  
   
   
       23 . The fiber bundle of  claim 22 , wherein the microfilaments have a cross-sectional shape selected from the group consisting of pie wedge, multi-lobal, hexagonal, rectangular, oval, and circular.  
   
   
       24 . A fabric comprising the fiber bundle of  claim 22 .  
   
   
       25 . The fabric of  claim 24 , wherein the fabric is selected from the group consisting of woven fabrics, nonwoven fabrics, and knit fabrics.  
   
   
       26 . A fabric comprising a plurality of multicomponent fibers of  claim 1 .  
   
   
       27 . The fabric of  claim 26 , wherein the fabric is selected from the group consisting of woven fabrics, nonwoven fabrics, and knit fabrics.  
   
   
       28 . A method of forming a microfilament-generating multicomponent fiber, comprising: 
 i) providing a first molten viscous polymer composition comprising a first synthetic polymer substantially soluble in a first solvent selected from the group consisting of water at a temperature of 70° C. or above, water at a temperature of less than 70° C., aqueous caustic solution, and a non-halogenated organic solvent;    ii) providing a second molten viscous polymer composition comprising a second synthetic polymer substantially soluble in a second aqueous solvent selected from the group consisting of water at a temperature of 70° C. or above, water at a temperature of less than 70° C., and aqueous caustic solution, wherein the first solvent and the second aqueous solvent are different such that the second synthetic polymer is not dissolvable in the first solvent;    iii) extruding the first molten viscous polymer composition and the second molten viscous polymer composition together through a spinneret to form a multicomponent fiber comprising one or more separate contiguous segments of each of the first polymer composition and the second polymer composition extending the length of the fiber, wherein at least a portion of the polymer segments comprising the second polymer composition are dimensioned to form microfilaments upon dissolution of the first polymer composition; and    iv) collecting the multicomponent fiber.    
   
   
       29 . The method of  claim 28 , further comprising dissolving the first polymer composition, thereby forming one or more microfilaments comprising the second polymer composition.  
   
   
       30 . The method of  claim 28 , further comprising forming a fabric comprising a plurality of the collected multicomponent fibers.  
   
   
       31 . The method of  claim 30 , further comprising dissolving the first polymer composition, thereby forming a fabric comprising a plurality of microfilaments comprising the second polymer composition.