Meltspun thermochromic fabrics

Abstract

The present invention relates to a method of achieving a uniform distribution of reversible thermochromic pigment within a spunmelt nonwoven fabric, by incorporating the reversible thermochromic pigment into the polymer melt at the time of fiber or filament formation. It has been found that incorporating the pigment into the polymer melt enhances thermochromic uniformity as well as fabric durability. In addition, the reversible thermochromic fabric is processed in a single formation step, resulting in the present invention being more efficient than those methods practiced in the prior art.

What is claimed is:  
     
         1 . A process of making a reversible thermochromic nonwoven fabric comprising: 
 a. providing a thermoplastic resin;    b. providing a reversible thermochromic pigment;    c. blending said thermoplastic resin and said reversible thermochromic pigment into a homogeneous blend;    d. extruding said homogeneous blend as continuous thermoplastic filaments;    e. collecting and consolidating said thermoplastic filaments into a nonwoven fabric; and    f. said nonwoven fabric exhibiting the ability to change color in response to heat.    
     
     
         2 . A process of making a reversible thermochromic nonwoven fabric as in  claim 1 , wherein said thermoplastic resin is selected from the group consisting of polyamides, polyester, polyolefins, and the combinations thereof.  
     
     
         3 . A process of making a reversible thermochromic nonwoven fabric as in  claim 2 , wherein said polyolefin is polypropylene.  
     
     
         4 . A process of making a reversible thermochromic nonwoven fabric as in  claim 1 , wherein said reversible thermochromic pigment is a melt additive comprising an electron-donating color former, electron-accepting developer, a thermally controlled color-changing agent, and ultra-violet absorbent chemistry.  
     
     
         5 . A process of making a reversible thermochromic nonwoven fabric as in  claim 1 , wherein said fabric exhibits the ability to change color within a temperature indicating range of 40° C.-60° C.  
     
     
         6 . A process of making a protective composite wrap as in  claim 1 , wherein said consolidating means is a thermal calendaring process.  
     
     
         7 . A reversible thermochromic nonwoven fabric comprising a nonwoven fabric comprised of a thermoplastic resin and a reversible thermochromic pigment.