Reduced density synthetic fiber utilizing hollow microcapsules

Abstract

The invention provides a synthetic fiber that includes: 0.4 to 30 wt % hollow microcapsules having an average diameter of 4 to 30 μm; and 70 to 99.6 wt % polymer material, wherein the synthetic fiber has a denier of 0.1 to 11.0. Also provided are yarn, insulation material, and articles that include the synthetic fiber, and methods of making the same.

1 . A synthetic fiber comprising:
 0.4 to 30 wt % hollow microcapsules having an average diameter of 4 to 30 μm; and   70 to 99.6 wt % polymer material,   
       wherein the synthetic fiber has a denier of 0.1 to 11.0. 
     
     
         2 . The synthetic fiber according to  claim 1 , wherein the hollow microcapsules are microspheres. 
     
     
         3 . The synthetic fiber according to  claim 1 , wherein the microcapsules are glass microspheres. 
     
     
         4 . The synthetic fiber according to  claim 1 , wherein the microcapsules are soda-lime borosilicate glass microspheres. 
     
     
         5 . The synthetic fiber according to  claim 1 , wherein the synthetic fiber is siliconized. 
     
     
         6 . The synthetic fiber according to  claim 1 , comprising 7 to 15 wt % of the hollow microcapsules. 
     
     
         7 . The synthetic fiber according to  claim 1 , wherein the hollow microcapsules have an average diameter of 5 to 20 μm. 
     
     
         8 . The synthetic fiber according to  claim 7 , wherein the hollow microcapsules have an average diameter of 4 to 12 μm. 
     
     
         9 . The synthetic fiber according to  claim 1 , wherein the hollow microcapsules are homogenously dispersed within the polymer material. 
     
     
         10 . The synthetic fiber according to  claim 1 , wherein the polymer material comprises nylon, polyester, polypropylene, acrylic or polyolefin polymer, or a combination thereof. 
     
     
         11 . The synthetic fiber according to  claim 10 , wherein the polymer material comprises polyester. 
     
     
         12 . The synthetic fiber according to  claim 11 , wherein the polyester is polyethylene terephthalate, polybutylene terephthalate, or a combination thereof. 
     
     
         13 . (canceled) 
     
     
         14 . The synthetic fiber according to  claim 1 , having a denier of 0.7 to 6.0. 
     
     
         15 . The synthetic fiber according to  claim 1 , wherein the fiber is a staple fiber having a length of 5 to 120 mm. 
     
     
         16 . (canceled) 
     
     
         17 . The synthetic fiber according to  claim 16 , wherein the fiber is crimped. 
     
     
         18 . (canceled) 
     
     
         19 . The synthetic fiber according to  claim 1 , additionally comprising aerogel particles. 
     
     
         20 . Insulation material comprising the synthetic fiber according to  claim 1 . 
     
     
         21 . Insulation material according to  claim 20 , wherein said insulation material is blowable insulation or filling material, comprising:
 a plurality of discrete, longitudinally elongated floccules each formed of a plurality of the synthetic fibers, the floccules including a relatively open enlarged medial portion and relatively condensed twisted tail portions extending from opposing ends of the medial portion.   
     
     
         22 . An article comprising the synthetic fiber according to  claim 1 . 
     
     
         23 . A method of making the synthetic fiber according to  claim 1 , said method comprising:
 mixing the hollow microcapsules and the polymer material, thereby forming a microcapsule/polymer mixture;   extruding the microcapsule/polymer mixture; and   optionally performing one or more additional processing steps,   thereby forming the synthetic fiber.