UV-curable coating composition for optical fiber for a fast cure and with improved adhesion to glass

Abstract

A UV-curable coating composition including an acrylate oligomer and a vinyl acrylate compound, the latter of which can act as both a reactive diluent and an adhesion promoter. The vinyl acrylate compounds have good miscibility and low viscosity, and impart to the cured primary coating a high adhesion to glass. With the use of a free radical photoinitiator, the vinyl acrylate compound increases the speed of cure of the uncured primary coating.

What is claimed is:  
     
         1 . A liquid, curable composition comprising a radiation curable oligomer, a free radical photoinitiator and a compound of formula (I):  
       
         
           
           
               
               
           
         
         wherein R is hydrogen or an alkyl group having 1 to 10 carbon atoms, said radiation curable oligomer being diluted with said compound of Formula (I), and said compound of Formula (I) being copolymerizable with said radiation curable oligomer.  
       
     
     
         2 . The composition of  claim 1 , wherein said compound of formula (I) is present in said coating composition in an amount of about 2 wt. % to about 25 wt. % based upon the total weight of the coating composition.  
     
     
         3 . The composition of  claim 1 , wherein said radiation curable oligomer is present in said coating composition in an amount of about 40 wt. % to about 95 wt. % based upon the total weight of the coating composition.  
     
     
         4 . The composition of  claim 1 , wherein said photoinitiator is present in said coating composition in an amount of about 0.1 wt. % to about 20 wt. % based upon the total weight of the coating composition.  
     
     
         5 . The composition of  claim 1  wherein, said radiation curable oligomer is a urethane acrylate oligomer.  
     
     
         6 . The composition of  claim 5 , wherein said urethane acrylate oligomer is formed by reacting a polyol with multifunctional isocyanate and then end-capping with hydroxy-functional acrylate.  
     
     
         7 . The composition of  claim 6 , wherein said polyol is selected from the group consisting of polyether polyol, polyester polyol, polycarbonate polyol, hydrocarbon polyol, polybutadiene polyol copolymers thereof and mixtures thereof.  
     
     
         8 . The composition of  claim 6 , wherein said multifunctional isocyanate is selected from the group consisting of aromatic polyisocyanate, aromatic aliphatic isocyanate, alicylic polyisocyanate and aliphatic polyisocyanate.  
     
     
         9 . The composition of  claim 1 , wherein in said compound of Formula (I), R is hydrogen.  
     
     
         10 . The composition of  claim 1 , wherein in said compound of Formula (I) R is a methyl group.  
     
     
         11 . A liquid, curable composition for coating an optical waveguide, comprising a UV curable urethane acrylate oligomer having either a polyether or polyester backbone, a free radical photoinitiator, and a compound of formula (I);  
       
         
           
           
               
               
           
         
         wherein R is hydrogen or an alkyl group having 1 to 10 carbon atoms, said difunctional urethane acrylate oligomer being diluted with said compound of Formula I, and said compound of Formula (I) being copolymerizable with said urethane acrylate oligomer.  
       
     
     
         12 . The composition of  claim 11 , wherein said urethane acrylate oligomer has a polyether backbone.  
     
     
         13 . The composition of  claim 11 , wherein said urethane acrylate oligomer has a polyester backbone.  
     
     
         14 . The composition of  claim 11 , wherein in said compound of Formula (I) R is hydrogen.  
     
     
         15 . The composition of  claim 11 , wherein in said compound of Formula (I) R is a methyl group.  
     
     
         16 . The composition of  claim 11 , wherein said compound of formula (I) is present in said coating composition in an amount of about 2 wt. % to about 25 wt. % based upon the total weight of the coating composition.  
     
     
         17 . The composition of  claim 11 , wherein said radiation curable oligomer is present in said coating composition in an amount of about 40 wt. % to about 95 wt. % based upon the total weight of the coating composition.  
     
     
         18 . The composition of  claim 11 , wherein said photoinitiator is present in said coating composition in an amount of about 0.1 wt. % to about 20 wt. % based upon the total weight of the coating composition.  
     
     
         19 . An optical waveguide have a cured coating thereon, said cured coating being prepared from a coating composition comprising a radiation curable oligomer, a free radical photoinitiator, and a vinyl acrylate compound of formula (I):  
       
         
           
           
               
               
           
         
         wherein R is hydrogen or an alkyl group having 1 to 10 carbon atoms, wherein said radiation curable oligomer being diluted with said compound of Formula (I), and said compound of Formula (I) being copolymerizable with said radiation curable oligomer.  
       
     
     
         20 . The optical waveguide of  claim 19 , wherein said compound of Formula (I) is present in said coating composition in an amount of about 2 wt. % to about 25 wt. % based upon the total weight of the coating composition.  
     
     
         21 . The optical waveguide of  claim 19 , wherein said radiation curable oligomer is present in said coating composition in an amount of about 40 wt. % to about 95 wt. % based upon the total weight of the coating composition.  
     
     
         22 . The optical waveguide of  claim 19 , wherein said photoinitiator is present in said coating composition in an amount of about 0.1 to about 20 wt. % based upon the total weight of the coating composition.  
     
     
         23 . The optical waveguide of  claim 19 , wherein, said radiation curable oligomer is a urethane acrylate oligomer.  
     
     
         24 . The optical waveguide of  claim 23 , wherein said urethane acrylate oligomer is formed by reacting a polyol with multifunctional isocyanate and then end-capping with hydroxy-functional acrylate.  
     
     
         25 . The optical waveguide of  claim 24 , wherein said polyol is selected from the group consisting of polyether polyol, polyester polyol, polycarbonate polyol, hydrocarbon polyol, polybutadiene polyol copolymers thereof and mixtures thereof.  
     
     
         26 . The optical waveguide of  claim 24 , wherein said multifunctional isocyanate is selected from the group consisting of aromatic polyisocyanate, aromatic aliphatic isocyanate, alicylic polyisocyanate and aliphatic polyisocyanate.  
     
     
         27 . The optical waveguide of  claim 19 , wherein in said compound of Formula (I) R is hydrogen.  
     
     
         28 . The optical waveguide of  claim 19 , wherein in said compound of Formula (I) R is a methyl group.  
     
     
         29 . An optical waveguide have a cured coating thereon, said cured coating being prepared from a liquid, curable composition, comprising a UV curable urethane acrylate oligomer having either a polyether backbone or polyester backbone, a free radical photoiniator, and a vinyl acrylate compound of formula (I):  
       
         
           
           
               
               
           
         
         wherein R is hydrogen or an alkyl group having 1 to 10 carbon atoms, and wherein said difunctional urethane acrylate oligomer being diluted with said vinyl acrylate compound, and said vinyl acrylate compound being copolymerizable with said difunctional urethane acrylate oligomer.  
       
     
     
         30 . The optical waveguide of  claim 29 , wherein said urethane acrylate oligomer has a polyether backbone.  
     
     
         31 . The optical waveguide of  claim 29 , wherein said urethane acrylate oligomer has a polyester backbone.  
     
     
         32  The optical waveguide of  claim 29 , wherein in said compound of Formula (I) R is hydrogen.  
     
     
         33 . The optical waveguide of  claim 29 , wherein in said compound of Formula (I) R is methyl group.  
     
     
         34 . The optical waveguide of  claim 29 , wherein said compound of formula (I) is present in said coating composition in an amount of about 2 wt. % to about 25 wt. % based upon the total weight of the coating composition.  
     
     
         35 . The optical waveguide of  claim 29 , wherein said radiation curable oligomer is present in said coating composition in an amount of about 40 wt. % to about 95 wt % based upon the total weight of the coating composition  
     
     
         36 . The optical waveguide of  claim 29 , wherein said photoinitiator is present in said coating composition in an amount of about 0.1 wt. % to about 20 wt. % based upon the total weight of the coating composition.