Adhesive made of acrylic resin

Liquid crystal box is usually used in liquid crystal display, such as TN liquid crystal box (TFT), STN liquid crystal box (STN), the structure of the liquid crystal element with a glass plate on each side of the material. On the surface of glass base plate material, optical films such as polarization film and phase delay film are laminated with adhesive composed mainly of acrylic resin. The general method of producing an optical laminate material consisting of a glass base plate material, an adhesive, and an optical film in this order is to first obtain an optical laminate film having an optical film and an adhesive layer consisting of an adhesive layer laminated on it, and then laminate the glass plate material on the surface of the adhesive layer.

This optical laminated film has a tendency to curl due to large size changes caused by expansion and contraction under heating or humidification and heating, resulting in blistering in the adhesive layer of the resulting optical laminated material and peeling (detachment) between the adhesive layer and the glass plate material. When heated or humidified and heated, the distribution of residual stress on the optical laminate film becomes uneven, and stress concentration occurs around the peripheral parts of the optical laminate material, resulting in light leakage in the TN liquid crystal cell (TFT). To solve this problem, an adhesive has been proposed. It is mainly composed of a structural unit of N-vinylpirolidone, that is, an acrylic resin derived from monomers with heterocyclic rings in the molecule (published Japanese patent application (JP-A) 5-107410). The problem, however, is that when liquid crystal cells made of optically laminated materials with adhesive layers are kept under humidified and heated conditions, Where the adhesive layer is composed mainly of acrylic resin with n-vinylpyrrolidone derived structural units, light leakage will occur.