Polymerization reactor and method for producing water absorbent resin

Abstract

A polymerization reactor of the present invention includes a container body 1 and a jacket 2 covering the outer surface of the container body 1 and defining a passage for passing a cooling/heating medium between itself and the outer surface of the container body. The container body 1 is made of a clad metal plate including a support metal layer 11 a having an inner surface at an inner side of the container body and an outer surface at an outer side of the container body, and an inner corrosion-resistant metal skin layer 11 b bonded to the inner surface of the support metal layer and being smaller in thickness than the support metal layer.

1 . A polymerization reactor for performing polymerization reaction, comprising:
 a container body; and   a jacket covering an outer surface of the container body and defining a passage for passing a cooling/heating medium between itself and the outer surface of the container body;   wherein the container body is made of a clad metal plate comprising a support metal layer having an inner surface at an inner side of the container body and an outer surface at an outer side of the container body, and an inner corrosion-resistant metal skin layer bonded to the inner surface of the support metal layer and being smaller in thickness than the support metal layer.   
     
     
         2 . The polymerization reactor according to  claim 1 , wherein the thickness of the inner skin layer is in a range of 1/10 to ½ of the thickness of the support metal layer. 
     
     
         3 . The polymerization reactor according to  claim 1 , wherein the clad metal plate further comprises an outer corrosion-resistant metal skin layer bonded to the outer surface of the support metal layer, the outer skin layer being smaller in thickness than the support metal layer. 
     
     
         4 . The polymerization reactor according to  claim 3 , wherein the support metal layer is made of carbon steel, whereas the inner skin layer and the outer skin layer are made of stainless steel. 
     
     
         5 . The polymerization reactor according to  claim 3 , wherein the inner skin layer is larger in thickness than the outer skin layer. 
     
     
         6 . The polymerization reactor according to  claim 1 , wherein the thickness of the support metal layer is 5 to 15 mm. 
     
     
         7 . The polymerization reactor according to  claim 1 , further comprising an inert gas supplier for supplying an inert gas into the passage. 
     
     
         8 . The polymerization reactor according to  claim 1 , wherein the jacket is internally portioned by a helical partition plate, the passage extending helically along the partition plate. 
     
     
         9 . The polymerization reactor according to  claim 1 , the container body has an open upper end that is closed by a lid. 
     
     
         10 . The polymerization reactor according to  claim 9 , wherein the lid is made of an additional clad metal plate comprising a support metal layer having an inner surface at the inner side of the container body and an outer surface at the outer side of the container body, and an additional inner corrosion-resistant metal skin layer bonded to the inner surface of the additional support metal layer and being smaller in thickness than the additional support metal layer. 
     
     
         11 . The polymerization reactor according to  claim 10 , wherein the additional clad metal plate further comprises an additional outer corrosion-resistant metal skin layer bonded to the outer surface of the additional support metal layer, the additional outer skin layer being smaller in thickness than the additional support metal layer. 
     
     
         12 . A method for producing a water absorbent resin by subjecting a water-soluble ethylenically unsaturated monomer to reversed phase suspension polymerization in a petroleum-based hydrocarbon dispersion medium, wherein the polymerization is performed in the container body of the polymerization reactor as set forth in  claim 1 .