Patent ID: 8331015

Claim:
A display medium comprising: a pair of substrates at least one of which has transparency and one of each surfaces of which are facing and disposed with a space therebetween; a dispersion medium sealed between the pair of substrates; a group of migrating particles dispersed in the dispersion medium so as to migrate in the dispersion medium according to an electric field formed between the pair of substrates; and a surface layer provided on at least one of the facing surfaces of the pair of substrates and including a polymer compound that is a copolymer containing the following constitutional unit (A) and constitutional unit (B): wherein in the constitutional units (A) and (B), X represents a group containing a silicone chain, Ra 1 and Ra 2 each independently represent a hydrogen atom or a methyl group, Rb 2 represents an organic group containing a fluorine atom, n1 and n2 each represent mol % of the constitutional unit relative to the whole copolymer and satisfy 0<n1<50 and 0<n2<50, respectively, and n represents a natural number of 1 or more and 3 or less.