Como substituir ' ou qualquer caractere especial ao usar XMLELEMENT Oracle

clear screen;
column res format a7;

select utl_i18n.unescape_reference(
          rtrim(
               xmlagg( -- use of xmlagg() function in 
                       -- this situation seems to be unnecessary 
                       XMLELEMENT(E,'I''m'||':')
                      ).extract('//text()'),':'
                )
        ) as res
 from dual;

RES   
-------
I'm