Exhaust pipe

Abstract

An exhaust pipe includes an exhaust pipe base and a surface coat layer. The surface coat layer is provided on the exhaust pipe base and includes an inorganic glass layer, an inorganic particle, and an inorganic binder. In the inorganic glass layer, a part of the inorganic binder is diffused and the inorganic particle and the rest of the inorganic binder in particulate form are dispersed. The inorganic glass layer includes at least one of SiO 2 —B 2 O 3 —ZnO glass, SiO 2 —B 2 O 3 —Bi 2 O 3 glass, SiO 2 —PbO glass, SiO 2 —PbO—B 2 O 3 glass, SiO 2 —B 2 O 3 —PbO glass, B 2 O 3 —ZnO—PbO glass, B 2 O 3 —ZnO—Bi 2 O 3 glass, B 2 O 3 —Bi 2 O 3 glass, B 2 O 3 —ZnO glass, and BaO—SiO 2 glass.

1 . An exhaust pipe comprising:
 an exhaust pipe base; and   a surface coat layer provided on said exhaust pipe base and comprising an inorganic glass layer, an inorganic particle, and an inorganic binder,   wherein, in said inorganic glass layer, a part of said inorganic binder is diffused and said inorganic particle and the rest of said inorganic binder in particulate form are dispersed, and   wherein said inorganic glass layer comprises at least one of SiO 2 —B 2 O 3 —ZnO glass, SiO 2 —B 2 O 3 —Bi 2 O 3  glass, SiO 2 —PbO glass, SiO 2 —PbO—B 2 O 3  glass, SiO 2 —B 2 O 3 —PbO glass, B 2 O 3 —ZnO—PbO glass, B 2 O 3 —ZnO—Bi 2 O 3  glass, B 2 O 3 —Bi 2 O 3  glass, B 2 O 3 —ZnO glass, and BaO—SiO 2  glass.   
     
     
         2 . The exhaust pipe according to  claim 1 ,
 wherein said inorganic binder comprises at least one of silicon and aluminum.   
     
     
         3 . The exhaust pipe according to  claim 1 ,
 wherein said inorganic glass layer has a softening temperature of higher than about 300° C.   
     
     
         4 . The exhaust pipe according to  claim 1 ,
 wherein a weight ratio of said inorganic glass layer, said inorganic particle, and said inorganic binder is about 6:4:3 to about 6:4:10.   
     
     
         5 . The exhaust pipe according to  claim 1 ,
 wherein said surface coat layer has an emissivity of about 0.7 or higher.   
     
     
         6 . The exhaust pipe according to  claim 1 ,
 wherein said inorganic particle comprises an oxide of at least one of manganese, iron, copper, cobalt, and chromium.   
     
     
         7 . The exhaust pipe according to  claim 1 ,
 wherein said inorganic particle comprises aluminum.