Abstract: A photochromic material comprising a styrene-based oligomer having a weight average molecular weight of from 200 to 6000 and a photochromic compound selected from the group consisting of spirooxazine derivatives and spiropyran derivatives.

Abstract: A photochromic material comprising a styrene-based oligomer having a weight average molecular weight of from 200 to 6000 and a photochromic compound selected from the group consisting of spirooxazine derivatives and spiropyran derivatives.

Abstract: A reversibly thermochromic light-transmitting laminate member which has a satisfactory thermochromic function and undergoes alternate color changes between a colorless transparent state and a colored transparent state.

Abstract: A reversibly thermochromic light-shielding/light-transmitting laminate member. More particularly, the invention relates to a reversibly thermochromic light-shielding/light-transmitting laminate member which changes not only in color but in transmittance with temperature.

Abstract: A reversibly thermochromic light-transmitting laminate member which has a satisfactory thermochromic function and undergoes alternate color changes between a colorless transparent state and a colored transparent state.

Abstract: A reversibly thermochromic light-shielding/light-transmitting laminate member. More particularly, the invention relates to a reversibly thermochromic light-shielding/light-transmitting laminate member which changes not only in color but in transmittance with temperature.

Abstract: A reversible thermochromic composition is provided which contains a specified diazarhodamine lactone derivative as an electron-donating color-developing organic compound, an electron-accepting compound, and a reaction medium for causing an electron exchange reaction between the components and reversibly at a specified temperature range. This reversible thermochromic composition develops clear reddish color at a colored state, and becomes colorless at a decolored state without residual color.

Abstract: A reversible thermochromic composition develops fluorescent color of yellow, yellowish orange, orange, reddish orange, or red with a high color density and high color brightness, yet gives no residual color under non-color-developing conditions, and has remarkably improved light resistance. The reversible thermochromic composition, comprising a solubilized mixture of three components of (a) an electron-donating color-developing organic compound selected from pyridine types, quinazoline types, and bisquinazoline types of compound, (b) an electron-accepting compound for the electron-donating color-developing organic compound, and (c) a compound serving as a reaction medium for causing reversibly an electron exchange reaction between the components (a) and (b) within a specified temperature range.