Particles for display device, image display medium using the same, and image forming device
An image display medium comprises a display substrate on which an image is displayed and a non-displaying substrate opposing to the substrate, wherein a spacer and black particles and white particles are enclosed between these substrates. The display substrate and non-display substrate each have a transparent electrode, wherein the transparent electrode for the non-display substrate is grounded and the transparent electrode for the display substrate is connected to voltage applying means. As these black particles and white particles, particles for a display device having a weight reduction rate of not more than 0.3% at 100° C. to 240° C. are respectively used.
1. Particles for a display device which can be positively or negatively charged and have a color, wherein
the particles have a weight reduction rate of not more than 0.3% at 100° C. to 240° C.
2. Particles for a display device according to claim 1 , wherein the particles are produced by a method comprising the step of suspension polymerization, emulsion polymerization or dispersion polymerization.
3. Particles for a display device according to claim 2 , wherein the particles are produced by undergoing an additional washing step.
4. Particles for a display device according to claim 3 , wherein the washing step is carried out by dispersing and stirring the particles in water or an organic solvent.
5. Particles for a display device according to claim 3 , wherein the washing step is carried out by dispersing the particles in a solvent and heating and applying a vacuum to the obtained dispersion liquid.
6. Particles for a display device according to claim 1 , wherein the particles comprise polymer particles.
7. Particles for a display device according to claim 6 , wherein the polymer particles are hollow particles.
8. An image display medium, which comprises a pair of opposed substrates and a group of particles comprising at least two or more kinds of particles, the group being enclosed in a gap between the pair of substrates, wherein at least one of the two or more kinds of particles can be positively charged and at least one of the other particles can be negatively charged, and the particles which can be positively charged and the particles which can be negatively charged have colors that are different from each other, and wherein the particles which can be positively charged and the particles which can be negatively charged have a weight reduction rate of not more than 0.3% at 100° C. to 240° C.
9. An image display medium according to claim 8 , wherein the particles which can be positively charged and the particles which can be negatively charged are produced by a method comprising the step of suspension polymerization, emulsion polymerization or dispersion polymerization.
10. An image display medium according to claim 9 , wherein the particles which can be positively charged and the particles which can be negatively charged are produced by undergoing an additional washing step.
11. An image display medium according to claim 10 , wherein the washing step is carried out by dispersing and stirring the particles in water or an organic solvent.
12. An image display medium according to claim 10 , wherein the washing step is carried out by dispersing the particles in a solvent and heating and applying a vacuum to the obtained dispersion liquid.
13. An image display medium according to claim 8 , wherein the particles which can be positively charged and the particles which can be negatively charged comprise polymer particles.
14. An image display medium according to claim 13 , wherein the polymer particles are hollow particles.
15. An image forming device comprising:
an image display medium comprising a pair of opposed substrates and a group of particles comprising at least two or more kinds of particles, which group is enclosed in a gap between the pair of substrates, wherein at least one of the two or more kinds of particles can be positively charged by external stimulation and at least one of the other particles can be negatively charged by external stimulation, and the particles which can be positively charged by external stimulation and the particles which can be negatively charged by external stimulation have colors that are different from each other; and
electric field production means for producing an electric field corresponding to an image, between the pair of substrates,
wherein the particles which can be positively charged and the particles which can be negatively charged have a weight reduction rate of not more than 0.3% at 100° C. to 240° C.
16. An image forming device according to claim 15 , wherein the particles which can be positively charged and the particles which can be negatively charged are produced by a method comprising the step of suspension polymerization, emulsion polymerization or dispersion polymerization.
17. An image forming device according to claim 16 , wherein the particles which can be positively charged and the particles which can be negatively charged are produced by undergoing an additional washing step.
18. An image forming device according to claim 17 , wherein the washing step is carried out by dispersing and stirring the particles in water or an organic solvent.
19. An image forming device according to claim 17 , wherein the washing step is carried out by dispersing the particles in a solvent and heating and applying a vacuum to the obtained dispersion liquid.
20. An image forming device according to claim 15 , wherein the particles which can be positively charged and the particles which can be negatively charged comprise polymer particles.
21. An image forming device according to claim 20 , wherein the polymer particles are hollow particles.