Curable silsesquioxane polymers, compositions, articles, and methods

Abstract

A curable silsesquioxane polymer, a composition including such polymer, an article having a layer disposed thereon that includes the curable polymer and/or the cured polymer, and a method of forming a cured coating, wherein the curable silsesquioxane polymer includes a three-dimensional branched network having the formula: wherein: the oxygen atom at the * is bonded to another Si atom within the three-dimensional branched network; R is an organic group comprising an ethylenically unsaturated group; n is an integer of greater than 3; and the —OH groups are present in an amount of at least 15 wt-% of the polymer.

What is claimed is: 
     
         1 . A curable silsesquioxane polymer comprising a three-dimensional branched network having the formula: 
       
         
           
           
               
               
           
         
       
       wherein:
 the oxygen atom at the * is bonded to another Si atom within the three-dimensional branched network; 
 R is an organic group comprising an ethylenically unsaturated group; 
 n is an integer of greater than 3; and 
 the —OH groups are present in an amount of at least 15 wt-% of the polymer. 
 
     
     
         2 . The curable silsesquioxane polymer of  claim 1  wherein the —OH groups are present in an amount of no greater than 60 wt-% of the polymer. 
     
     
         3 . The curable silsesquioxane polymer of  claim 1  wherein n is an integer of no greater than 100. 
     
     
         4 . The curable silsesquioxane polymer of  claim 1  wherein R has the formula —Y—Z, wherein Y is a bond, an alkylene group, an arylene group, or a combination thereof, and Z is an ethylenically unsaturated group selected from a vinyl group, a vinylether group, a (meth)acryloyloxy group, and a (meth)acryloylamino group. 
     
     
         5 . The curable silsesquioxane polymer of  claim 4  wherein Y is a bond, a (C1-C20)alkylene group, a (C6-C12)arylene group, a (C6-C12)alk(C1-C20)arylene group, a (C6-C12)ar(C1-C20)alkylene group, or a combination thereof. 
     
     
         6 . The curable silsesquioxane polymer of  claim 1  which has peel force from glass of at least 1 N/dm. 
     
     
         7 . A curable silsesquioxane polymer comprising a three-dimensional branched network which is a condensation reaction product of a compound having the formula Z—Y—Si(R 1 ) 3 , wherein:
 Y is a bond, an alkylene group, an arylene group, or a combination thereof; 
 Z is an ethylenically unsaturated group selected from a vinyl group, a vinylether group, a (meth)acryloyloxy group, and a (meth)acryloylamino group; and 
 each R 1  group is independently a hydrolyzable group; 
 wherein the polymer includes —OH groups in an amount of at least 15 wt-% of the polymer. 
 
     
     
         8 . The curable silsesquioxane polymer of  claim 7  wherein Y is a bond, a (C1-C20)alkylene group, a (C6-C12)arylene group, a (C6-C12)alk(C1-C20)arylene group, a (C6-C12)ar(C1-C20)alkylene group, or a combination thereof. 
     
     
         9 . A curable composition comprising a photoinitiator and the curable silsesquioxane polymer of  claim 1 . 
     
     
         10 . The curable composition of  claim 9  wherein the photoinitiator is a free-radical photoinitiator. 
     
     
         11 . The curable composition of  claim 9  further comprising nanoparticles. 
     
     
         12 . The curable composition of  claim 9  further comprising an organic solvent. 
     
     
         13 . An article comprising a substrate and the curable composition of  claim 9  in a layer disposed on at least a portion of at least one surface of the substrate. 
     
     
         14 . An article comprising a substrate and a cured coating layer prepared by UV curing the composition of  claim 9  disposed on at least a portion of at least one surface of the substrate. 
     
     
         15 . A method of making a cured coating on a substrate surface, the method comprising:
 coating a curable composition of  claim 9  on at least a portion of at least one substrate surface;   optionally exposing the coated curable composition to conditions that allow an organic solvent, if present, to evaporate from the curable composition; and   UV curing the curable composition.