Particles and a process for preparing the same

Abstract

Disclosed are a plurality of particles having a narrow particle size distribution, a processes for forming the same, and films containing the same. The plurality of particles, includes one or more discrete polymer shells, wherein at least one of the polymer shells is crosslinked with at least one monomer containing two or more double bonds polymerizable by free radical means; and a core material encased in the polymer shells, wherein the plurality of particles have a polydispersity of from 1.3 to 1.0.

What is claimed is:  
     
         1 . A process for forming a plurality of particles, comprising the steps of: 
 (A) providing a first emulsion comprising a core material and one or more monomers in an aqueous phase, wherein at least one of the monomers is a monomer containing two or more double bonds, and a second emulsion comprising seed particles;    (B) combining the first emulsion and the second emulsion;    (C) forming discrete domains, in the aqueous phase, wherein the domains comprise the core material and the one or more monomers, and    (D) polymerizing the one or more monomers to form a plurality of particles, each particle comprising a discrete crosslinked polymer shell encasing the core material,    wherein the plurality of particles have a polydispersity of from 1.3 to 1.0.    
     
     
         2 . The process of  claim 1 , wherein the core material comprises liquid crystal material.  
     
     
         3 . The process of  claim 1 , wherein at least one transport agent is added prior to step (C).  
     
     
         4 . The process of  claim 1 , further comprising forming at least one additional polymer shell on the crosslinked polymer shell encasing the core material.  
     
     
         5 . A process for forming a plurality of particles, comprising the steps of: 
 (A) providing a first emulsion comprising a core material in an aqueous phase and a second emulsion comprising seed particles;    (B) combining the first emulsion and the second emulsion;    (C) forming discrete domains, in the aqueous phase, wherein the domains comprise the core material;    (D) adding one or more monomers to the discrete domains, wherein at least one of the monomers is a monomer containing two or more double bonds;    (E) polymerizing the one or more monomers to form a plurality of particles, each particle comprising a discrete crosslinked polymer shell encasing the core material,    wherein the plurality of particles have a polydispersity of from 1.3 to 1.0.    
     
     
         6 . The process of  claim 5 , wherein the core material is liquid crystal material.  
     
     
         7 . The process of  claim 5 , wherein at least one transport agent is added prior to step (C).  
     
     
         8 . The process of  claim 7 , wherein at least one transport agent is removed after the forming of the discrete domains.  
     
     
         9 . The process of  claim 5 , further comprising forming at least one additional polymer shell on the crosslinked polymer shell encasing the core material.  
     
     
         10 . A plurality of particles, each particle comprising: 
 (A) one or more discrete polymer shells, wherein at least one of the polymer shells is crosslinked with at least one monomer containing two or more double bonds; and    (B) a core material encased in the polymer shells,    wherein the plurality of particles have a polydispersity of from 1.3 to 1.0.    
     
     
         11 . The particles of  claim 10 , wherein the core material comprises a liquid crystal.  
     
     
         12 . A film formed from the particles of  claim 11 .  
     
     
         13 . The particles of  claim 10 , wherein the core material comprises a gas.  
     
     
         14 . An article of manufacture, comprising at least one resin having the particles of  claim 13  dispersed therein.  
     
     
         15 . A polymer particle comprising: 
 (A) one or more discrete polymer shells, wherein at least one of the polymer shells is crosslinked with at least one monomer containing two or more double bonds; and    (B) a core material encased in the polymer shells,    wherein a plurality of the polymer particles have a polydispersity of from 1.3 to 1.0.    
     
     
         16 . The polymer particle of  claim 15 , wherein the core material comprises a liquid crystal.  
     
     
         17 . A film formed from a plurality of the polymer particle of  claim 16 .  
     
     
         18 . The polymer particle of  claim 15 , wherein the core material comprises a gas.  
     
     
         19 . An article of manufacture, comprising at least one resin having a plurality of the polymer particle of  claim 18  dispersed therein.  
     
     
         20 . A process for forming a plurality of particles, comprising the steps of: 
 (A) providing 
 (i) a first emulsion comprising a core material in an aqueous phase,  
 (ii) a second emulsion comprising seed particles; and  
 (iii) one or more monomers, wherein at least one of the monomers is a monomer containing two or more double bonds;  
   (B) combining the first emulsion, the second emulsion, and the one or more monomers;    (C) forming discrete domains, in the aqueous phase, wherein the domains comprise the core material;    (D) polymerizing the one or more monomers to form a plurality of particles, each particle comprising a discrete crosslinked polymer shell encasing the core material,    wherein the plurality of particles have a polydispersity of from 1.3 to 1.0.    
     
     
         21 . The process of  claim 1 , wherein the core material is an operationally nematic liquid crystal.  
     
     
         22 . The process of  claim 5 , wherein the core material is an operationally nematic liquid crystal.  
     
     
         23 . The plurality of particles of  claim 10 , wherein the core material is an operationally nematic liquid crystal.  
     
     
         24 . A film formed from the plurality of particles of  claim 23 .  
     
     
         25 . The polymer particle of  claim 15 , wherein the core material is an operationally nematic liquid crystal.  
     
     
         26 . A film formed from a plurality of the polymer particle of  claim 25 .  
     
     
         27 . The process of  claim 20 , wherein the core material is a liquid crystal  
     
     
         28 . The process of  claim 20 , wherein the core material is an operationally nematic liquid crystal.