Photosensitive resin composition for optical waveguides, and optical waveguide and manufacturing method thereof

Abstract

There is provided a photosensitive resin composition for forming an optical waveguide which has high shape precision and excellent transmission characteristics under high temperature and high humidity. A composition of the present invention contains (A) a polymer having structures represented by the following general formulae (1) and (2) (in the formulae, each of R 1 and R 2 is independently a hydrogen atom or an alkyl group having 1 to 12 carbon atoms; R 3 is an organic group containing a radical-polymerizable reactive group; X is a single bond or a bivalent organic group; and Y is a non-polymerizable organic group), (B) a compound having at least one ethylenic unsaturated group in the molecule thereof, having a molecular weight below 1,000 and having a boiling point of at least 130° C. at 0.1 MPa, and (C) a photoradical polymerization initiator.

1 . A photosensitive resin composition for optical waveguides, containing: 
 (A) a polymer containing structures represented by the following general formulae (1) and (2)                          (in the formulae, each of R 1  and R 2  is independently a hydrogen atom or an alkyl group having 1 to  12  carbon atoms, R 3 is an organic group containing a radical-polymerizable reactive group, X is a single bond or a bivalent organic group, and Y is a non-polymerizable organic group);    (B) a compound having at least one ethylenic unsaturated group in the molecule thereof, having a molecular weight below 1,000 and having a boiling point of at least 130° C. at 0.1 MPa; and    (C) a photoradical polymerization initiator.    
     
     
         2 . The photosensitive resin composition according to  claim 1 , wherein component (A) is a polymer containing structures represented by the following general formulae (3) and (4)  
       
         
           
           
               
               
           
         
       
       (in the formulae, each of R 1  and R 2  is independently a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, R 4  is a hydrogen atom or a methyl group, each of X and Z independently is a single bond or a bivalent organic group, and Y is a non-polymerizable organic group).  
     
     
         3 . The photosensitive resin composition according to  claim 1 , further containing (D) an organic solvent.  
     
     
         4 . An optical waveguide comprising a lower clad layer, a core portion, and an upper clad layer, wherein at least one of the lower clad layer, the core portion, and the upper clad layer comprises a cured material of a photosensitive resin composition according to  claim 1 .  
     
     
         5 . The optical waveguide according to  claim 4 , wherein each of the lower clad layer, the core portion, and the upper clad layer comprises a cured material of a photosensitive resin composition according to  claim 1 , and the core portion has a refractive index at least 0.1% greater than the refractive index of each of the lower clad layer and the upper clad layer.  
     
     
         6 . A method of manufacturing an optical waveguide comprising a lower clad layer, a core portion, and an upper clad layer, wherein the method comprises the steps of forming the lower clad layer, forming the core portion, and forming the upper clad layer, and wherein at least one of these steps is a photocuring step of curing a photosensitive resin composition according to  claim 1  by irradiating the composition with light.