Patent ID: 7561140
Filing Date: 2009-07-14
Classification: G02F,G09F

Abstract:
1. A microcapsule magnetic migration display, in which a plurality of microcapsules, in which a dispersion liquid containing an oily dispersion medium having two components of light-absorptive magnetic particles and light-reflective non-magnetic particles dispersed therein is encapsulated to form a microcapsule-encapsulated dispersion liquid, are arrayed on a substrate, and positions of the two components in the dispersion medium are allowed to vertically migrate in the microcapsules by a magnetic field applied from outside the substrate, to thereby form character or image of a black color or a white color on the white color or the black color, respectively, or erase therefrom, wherein: (1) the microcapsule-encapsulated dispersion liquid comprises one kind or two or more kinds of oily liquids having a flash point of 70° C. or more, a volume density at 15° C. of 0.75 to 0.91 g/cm (2) the microcapsule-encapsulated dispersion liquid is added with 0.5 to 8.0 wt % of non-ionic surfactant with an HLB value of 5.0 or less, which is liquid under room temperature; and (3) to increase the volume density of the microcapsule-encapsulated dispersion liquid, the microcapsule-encapsulated dispersion liquid is added with solid particles having a true specific gravity exceeding 1.0 and having a particle diameter of 0.1 to 30 μm, to thereby adjust the volume density of the microcapsule-encapsulated dispersion liquid at 15° C. to 1.0 to 1.2 g/cm