abstract |
The present invention comprises (a) methyl methacrylate units, (b) ethyl acrylate units, (c) n-butyl acrylate units, (d) 2-methoxyethyl acrylate units, and (e) crosslinking site monomer units, with the (a) methyl methacrylate units at 10-20wt%, the (b) ethyl acrylate units at 15wt% or less, the (c) n-butyl acrylate units at 60-80wt%, the (d) 2-methoxyethyl acrylate units at 10-30wt%, and the (e) crosslinking site monomer units at 0.5-5wt%. |