Reduced density hollow glass microsphere polymer composite

Abstract

The invention relates to a hollow glass microsphere and polymer composite having enhanced viscoelastic and rheological properties.

1 - 95 . (canceled) 
     
     
         96 . A melt processing method of manufacturing a hollow glass microsphere and polymer composite from a mixture, said method comprising:
 (a) pre-treating a hollow glass microsphere with an effective composite forming amount of an interfacial modifier coating wherein the hollow glass microsphere has a particle size of at least about 5 microns;   (b) combining a thermoplastic polymer phase with about 30 to 95 volume % of a pre-treated interfacial modifier coated hollow glass microsphere, in an amount that can substantially occupy excluded volume of a hollow glass microsphere particle distribution in the composite; and   (c) melt process compounding the mixture to form the composite comprising the pre-treated hollow glass microspheres within the polymer phase;   
       wherein the hollow glass microsphere exhibits a circularity greater than 13 and an aspect ratio less than 1:3; and wherein the interfacial modifier coating allows for greater freedom of movement between the pre-treated hollow glass microsphere within the polymer phase compared to the same composite without the exterior coating on the hollow glass microsphere, when measured under the same conditions. 
     
     
         97 . The method according to  claim 96 , wherein about 40 to 70 volume % of the hollow glass microsphere composite comprises the polymer phase. 
     
     
         98 . The method according to  claim 96 , wherein the composite comprises about 0.02 to 3 wt.-% of the interfacial modifier. 
     
     
         99 . The method of  claim 96  wherein the polymer phase has a density of about 0.86 gm-cm −3 . 
     
     
         100 . The method of  claim 96 , wherein the composite has a density of about 0.4 to 5 gm-cm −3 . 
     
     
         101 . The method of  claim 96  wherein the composite additionally comprises a solid particulate or a fiber, the particulate having a particle size (P s ) of about 5 to 1000 microns and the fiber having an aspect ratio of greater than 10. 
     
     
         102 . The method of  claim 96  wherein after compounding, the method includes extruding the composite. 
     
     
         103 . The method of  claim 97  wherein the polymer phase comprises a polyamide, poly (ethylene-co-vinyl acetate), a synthetic rubber, a polyvinyl chloride, a fluoropolymer, a polyolefin, a thermoset polymer. 
     
     
         104 . The method according to  claim 96 , wherein said melt processing comprises injection molding the composite. 
     
     
         105 . The method according to  claim 96 , wherein said melt processing comprises compression molding the composite. 
     
     
         106 . The composite formulation of  claim 96  wherein the microsphere is a hollow glass microsphere. 
     
     
         107 . The composite formulation of  claim 96  wherein the composite formulation has a tensile strength of about 0.1 to 10 times that of the polymer phase. 
     
     
         108 . The composite of  claim 96  wherein the composite formulation has a tensile elongation of about 15% to 90% of the polymer phase. 
     
     
         109 . The composite of  claim 96  wherein the composite formulation has a thermoplastic shear at least about 5 sec −1 . 
     
     
         110 . The composite formulation of  claim 96  wherein the composite formulation has a tensile strength of at least 0.2 MPa and a thermoplastic shear of at least 5 sec −1    
     
     
         111 . The composite formulation of  claim 96  wherein the hollow glass microsphere has a particle size P S  of about 5 to 300 microns.