Radiation curable resin composition

Abstract

The present invention provides a curable composition, comprising: a (meth)acrylate urethane compound derived from a polypropylene glycol or a propyleneoxide ethyleneoxide copolymer glycol having a molecular weight between 1,000 and 13,000 and an amount of unsaturation less than 0.01 meq/g. The liquid curable resin composition of the present invention has improved liquid stability and can produce cured products having superior mechanical characteristics by polymerization. The composition further comprises preferably a primary or secondary amine. The liquid curable resin composition can be used as a coating material for optical fibers, adhesives, and the like. The composition is particularly suitable as a coating material for optical fibers for which long-term stability is required.

1 . A liquid radiation curable resin composition for fiber optic coating materials comprising: a (meth)acrylate urethane compound derived from a polypropylene glycol or a copolymer comprising propyleneoxide and ethyleneoxide (hereinafter: said polypropylene glycol) having a molecular weight, between 1,000 and 13,000 and an amount of unsaturation of less than 0.01 meq/g.  
   
   
       2 . The composition according to  claim 1 , wherein said polypropylene glycol has a molecular weight of between 2,000 and 8,000.  
   
   
       3 . The composition according to  claim 1 , wherein said polypropylene glycol has an amount of unsaturation between 0.0001 and 0.009 meq/g.  
   
   
       4 . The composition according to  claim 1 , wherein the (meth)acrylate urethane compound further comprises, within the backbone, other polymeric units.  
   
   
       5 . The composition according to  claim 4 , wherein the other polymeric units include polyethers, polyesters, polycarbonates, polyolefins, copolymers thereof and mixture therefrom.  
   
   
       6 . The composition according to  claim 1 , wherein the (meth)acrylate urethane compound is derived from aromatic and/or aliphatic diisocyanates.  
   
   
       7 . The curable composition according to  claim 1 , wherein the urethane compound is prepared by reacting 
 (a.1) said polypropylene glycol, and optionally    (a.2) a further polyol or mixture of polyols    (b) a polyisocyanate, and    (c) a (meth)acrylate containing a hydroxyl group.    
   
   
       8 . A curable resin composition for optical fibers comprising (a) 40-95 wt % of polyurethane having a polyoxyalkylene structure, in which the weight ratio of propylene oxide and ethylene oxide is 100:0 to 80:20, and an ethylenically unsaturated group, (b) 3-50 wt % of mono-functional (meth)acrylate of which the homopolymer has a glass transition temperature of 20° C. or less, and (c) 0.01-5 wt % of primary or secondary amine compound, wherein wt % is based on the total amount of the components (a), (b), and (c).  
   
   
       9 . A cured product obtained by curing the curable resin composition according to  claim 8 , wherein the amount of hydrogen gas generated when the cured product is allowed to stand at 100° C. for two days is 2.0 μl/g or less.  
   
   
       10 . A substrate comprising a cured coating obtained by radiation curing the composition according to  claim 1 .  
   
   
       11 . The substrate according to  claim 10 , wherein the substrate is a bare optical glass fiber, an optical glass fiber coated with a primary coating, an optical glass fiber coated with a secondary coating, at least two coated optical glass fibers or at least 2 ribbons comprising at least two coated optical glass fibers.  
   
   
       12 . An optical fiber, ribbon or cable comprising at least one coating obtained by curing the curable composition according  claim 1.