an aspect of the present invention provides a monomer from which a polymer layer capable of keeping high display quality even in high temperature and high humidity environments can be formed . the monomer in an aspect of the present invention is a compound represented by p - sp 1 - z 2 - a 1 - n1 - z 3 - sp 2 - p : in the formula , p denotes the same or different radical polymerizable group ; and at least one of z 1 , z 2 , and z 3 denotes — nrco — or — conr — group .