Multicomponent fibers comprising a dissolvable starch component, processes therefor, and fibers therefrom

Abstract

A melt spinnable fiber is provided that comprises a first component comprising a thermoplastic polymer, and a second component comprising thermoplastic starch where the second component is not encompassed by another component or components or if encompassed by another component or components then the second component encompasses a hollow core. A particular use of such a fiber is for removal of the second component in the presence of a solvent in order to produce fibers with desired properties. An agent may be present in the second component for controlling the rate of removal of the second component thereby allowing for physical manipulation of the fiber prior to complete removal of the component. The invention is also directed to nonwoven webs and disposable articles comprising the fibers.

What is claimed is:  
     
         1 . A melt spinnable multicomponent fiber having a diameter of less than 200 microns, comprising: 
 a first component comprising a thermoplastic polymer; and    a second component comprising thermoplastic starch,    wherein the second component is not encompassed by another component or components or if encompassed by another component or components then the second component encompasses a hollow core.    
     
     
         2 . The melt spinnable multicomponent fiber of  claim 1  wherein the second component further comprises an agent selected from the group consisting of an acid substituted vinyl polymer, a polyolefin carboxylic acid copolymer, a polyhydroxyetherester, a polyhydroxyetheramide, a C8-C22 aliphatic saturated or unsaturated carboxylic acid, an aliphatic carboxyamide, and an aromatic carboxyamide.  
     
     
         3 . The melt spinnable multicomponent fiber of  claim 1  wherein the second component comprises an acid substituted vinyl polymer and the acid substituted vinyl polymer is ethylene acrylic acid.  
     
     
         4 . The melt spinnable multicomponent fiber of  claim 1  wherein the second component comprises a polyolefin carboxylic acid copolymer and the copolymer is ethylene maleic acid copolymer, ethylene methacrylic acid copolymer, or ethylene acrylic acid copolymer.  
     
     
         5 . The melt spinnable multicomponent fiber of  claim 1  wherein the fiber has a sheath-core configuration, the first component is in the core configuration and the second component is in the sheath configuration.  
     
     
         6 . The melt spinnable multicomponent fiber of  claim 1  wherein the fiber has a configuration selected from the group consisting of islands-in-the-sea, ribbon, segmented pie, side-by-side, and a combination thereof.  
     
     
         7 . The melt spinnable multicomponent fiber of  claim 1  wherein the thermoplastic polymer is selected from the group consisting of polypropylene, polypropylene copolymer, polyethylene, polyethylene copolymer, polyamide, polyvinyl alcohol, ethylene vinyl alcohol, polyolefin copolymer, polyolefin carboxylic acid copolymer, polyester, and a combination thereof.  
     
     
         8 . The melt spinnable multicomponent fiber of  claim 1  wherein the thermoplastic polymer is biodegradable.  
     
     
         9 . The melt spinnable multicomponent fiber of  claim 8  wherein the biodegradable thermoplastic polymer is selected from a group consisting of a crystallizable polylactic acid, a diacid/diol aliphatic polyester, an aliphatic/aromatic copolyester, a polyhydroxyalkanoate, a copolymer thereof, and a combination thereof.  
     
     
         10 . A melt spinnable fiber having a diameter of less than 200 microns, the fiber produced by a process comprising: 
 compounding a first component comprising a thermoplastic polymer;    compounding a second component comprising destructured starch; and    spinning the first component with the second component to form a fiber having a diameter of less than 200 microns, wherein the second component is not encompassed by another component or components or if encompassed by another component or components then the second component encompasses a hollow core.    
     
     
         11 . A melt spinnable fiber of  claim 10  produced by a process further comprising 
 contacting the fiber with a solvent for the second component,  
 wherein the second component is removed from the fiber by exposure to the solvent.  
 
     
     
         12 . The melt spinnable fiber of  claim 10  wherein the compounding of the second component further includes an agent selected from the group consisting of an acid substituted vinyl polymer, a polyolefin carboxylic acid copolymer, a polyhydroxyetherester, a polyhydroxyetheramide, a C8-C22 aliphatic saturated or unsaturated carboxylic acid, an aliphatic carboxyamide, and an aromatic carboxyamide, and wherein the process further comprises 
 contacting the fiber with a solvent for the second component,  
 wherein the second component is removed from the fiber by exposure to the solvent at a rate that is slower than that of a fiber lacking the agent.  
 
     
     
         13 . A process of producing a melt spinnable fiber having a diameter of less than 200 microns, comprising: 
 compounding a first component comprising a thermoplastic polymer;    compounding a second component comprising destructured starch;    spinning the first component with the second component to form a fiber having a diameter of less than 200 microns, wherein the second component is not encompassed by another component or components or if encompassed by another component or components then the second component encompasses a hollow core.    
     
     
         14 . The process of  claim 13  further comprising contacting the fiber with a solvent for the second component wherein the second component is removed from the fiber by exposure to the solvent.  
     
     
         15 . The process of  claim 13  wherein the compounding of the second component further includes an agent selected from the group consisting of an acid substituted vinyl polymer, a polyolefin carboxylic acid copolymer, a polyhydroxyetherester, a polyhydroxyetheramide, a C8-C22 aliphatic saturated or unsaturated carboxylic acid, an aliphatic carboxyamide, and an aromatic carboxyamide, wherein the second component is removed from the fiber by exposure to the solvent at a rate that is slower than that of a fiber lacking the agent.  
     
     
         16 . The process of  claim 15  further comprising physically manipulating the fiber prior to complete removal of the second component.  
     
     
         17 . A nonwoven web comprising the multicomponent fiber of  claim 1 .  
     
     
         18 . A disposable article comprising the nonwoven web of  claim 17 .  
     
     
         19 . A nonwoven web comprising the fiber of  claim 12 .  
     
     
         20 . A disposable article comprising the nonwoven web of  claim 19.