US 9,612,535 B2  100  99  -continued  -----f  CH2 - CH r- -continued  The resin (Ab) may preferably have the repeating unit  consisting of the (meth) acrylate derivative not decompos- able by an acid. Hereinafter, specific examples thereof will  be shown, but the present invention is not limited thereto.  The content of the repeating unit having the acid-decom› posable group in the resin (Ab) is preferably 5 to 95 mo!%,  more preferably 10 to 60 mo! %, and particularly preferably  15 to 50 mo! % based on the total repeating unit.  The content of the repeating unit represented by Formula  (Al) in the resin (Ab) is preferably O to 90 mo! %, more  preferably 10 to 70 mo! %, and particularly preferably 20 to  50 mo! % based on the total repeating unit.  The content of the repeating unit represented by Formula  (A2) in the resin (Ab) is preferably O to 90 mo! %, more  preferably 5 to 75 mo!%, and particularly preferably 10 to  60 mo! % based on the total repeating unit.  The content of the repeating unit represented by Formula  (A3) in the resin (Ab) is preferably O to 90 mo! %, more  preferably 5 to 75 mo!%, and particularly preferably 10 to  60 mo! % based on the total repeating unit.  The content of the repeating unit represented by Formula  (A5) in the resin (Ab) is preferably O to 50 mo! %, more  preferably O to 40 mo! %, and particularly preferably Oto 30  mo! % based on the total repeating unit.  The resin (Ab) may also have the repeating unit repre› sented by Formula (A6), and thus is preferred from the  viewpoint of enhancing the film quality and inhibiting the  film decrease of the non-exposure parts. The content of the  repeating unit represented by Formula  (AS)  is preferably 0  to 50 mo! %, more preferably Oto 40 mo! %, and particularly  preferably O to 30 mo! % based on the total repeating unit.  Further, in the resin (Ab), in order to maintain good  developability in an alkali developer, appropriate other  polymerizable monomers may be copolymerized to intro› duce an alkali-soluble groups such as a phenolic hydroxyl  group and a carboxyl group, and in order to improve the film  quality, other hydrophobic polymerizable monomers such as  a alkyl acrylate or alkyl methacrylate may be copolymer› ized.  A monomer corresponding to the repeating unit repre› sented by Formula (A2) may be synthesized by esterifying  a (meth)acrylic acid chloride and an alcohol compound in a  solvent such as THF, acetone, or methylene chloride under  the presence of a basic catalyst such as triethylamine,  pyridine or DBU. Further, a commercially available mono› mer may be used.  A monomer corresponding to the repeating unit repre- sented by Formula (Al) may be synthesized by acetalizing  a hydroxyl substituted styrene monomer and a vinylether  compound in a solvent such as THF or methylene chloride 