-continued  -continued  38  US  9,104,101 B2  37  (al-3)  J H 2  R>  c,.._I  C  I  O=C  \ $_{0 }$ I  y2  I  O=C  ’o  I  X’  (al-1-2)  (al-4)  J H 2  R>  c,I  C  I  O=C  \  0  I  y2  I  O=C  ’o  I ,  I  2’  R -C-R  I  0  ~  CH2  ~  n  y  (al-1-3)  (al-1-4)  (al-1-5)  (al-1-6)  (al-1-7)  (al-1-1)  [Chemical Formula 15]  In the formulas shown below, R"’ represents a hydrogen  atom, a methyl group or a trifluoromethyl group.  Specific examples of the structural units represented by  general formulas (al-1) to (al-4) are shown below.  Examples ofY $^{2 }$include the same groups as those described  above for Y $^{2 }$in general formula (al-0-2).  R 11 , R 21 , n andY are the same as defined above for R 11 , R 21 ,  n and Y respectively in general formula (pl) within the  description relating to the "acetal-type acid-dissociable  group".  In the above formulas, examples of X 1  include the same  tertiary alkyl ester-type acid-dissociable groups as those  described above.  In the formulas, R, R  11 , R  21 , n, Y and Y 2  are each the same as  defined above, and X 1  represents a tertiary alkyl ester-type  acid-dissociable group. 