| 摘要 |
PURPOSE:To change color tone, volume, electric conductivity, etc. by using a crosslink type water absorptive resin having the specific constituting unit at the main chain and irradiating light thereto in the presence of water or hydrophilic medium. CONSTITUTION:The crosslink type water absorptive resin having the constituting unit expressed by the formula is used. Such resin is obtd. by adding the vinyl polymer corresponding to the above-described formula to a hydrophilicity imparting monomer, for example, acrylamide, etc. and crosslinkable monomer, for example, N,N'-methylene bis-acryl amide, etc. and copolymerizing the same. The crosslink type water absorptive resin obtd. in such a manner exhibits a strong absorption spectrum in a UV - visible region and causes a constitutional change and consequent color tone change, etc. by way of a photochemical reaction process when irradiated with light. The resin changes to a swollen gel body while entailing a change in the pH and electric conductivity of the gel when light is irradiated thereto particularly in the presence of the aq. medium. The gel shrinks when the light is shut therefrom. The resin is made usable for an optical switch, optical recording material, shape memory material, etc. by utilizing such change of the photochemical characteristic. |
