A microcapsule magnetic writing board

Abstract

The invention mainly discloses a microcapsule magnetic writing board and a preparation method thereof. The writing board is composed of a front-surface polyester film layer, an adhesion force-reinforcing coating, a microcapsule coating, a back-surface adhesive layer and a back-surface film layer, wherein microcapsules are internally encapsulated with magnetic particles, white colour fillers, a solvent, reactive monomers and auxiliaries. When a magnetic pen is used for writing on the front surface of the writing board, the magnetic particles in the microcapsules migrate upwards to display an image, the image is fine, clear, high in contrast and capable of being eliminated by a magnetic stripe on the back surface of the writing board. The writing board disclosed by the invention can be applied in the fields of toys, culture and education, and the like.

Description

technical field [0001] The invention belongs to the field of toys and culture and education, and in particular relates to a microcapsule magnetic writing board. Background technique [0002] The technology used in the traditional magnetic writing board is mainly to encapsulate the solution dispersed with magnetic powder particles and white particles in a small chamber arranged in a honeycomb shape. Under the magnetic attraction, the magnetic powder particles migrate upward in the solution to show a black image. Such as patent CN97116111.9, CN99801630.6. Although this technology has good black-and-white image contrast, but limited by the preparation process, the size of the honeycomb-shaped cavity is too large, resulting in low image resolution, discontinuous writing breakpoints, and cannot form a delicate and clear writing effect. Another disadvantage of this technology is The magnetic powder particles are easy to settle in the cavity, resulting in unstable image display. ...

AI Technical Summary

Problems solved by technology

The magnetic writing board prepared by the above technology, because the size of the microcapsules is much smaller than the cavity of the traditional honeycomb structure, and the microcapsules are closely arranged, so the image resolution is high, and the handwriting is clear and delicate, but the above technology still has certain defects. Patent CN95115366.8, CN98102345.2, CN00109731.8, CN00109809.8 have used high boiling point solvent and medium and low boiling point solvent simultaneously in the solvent encapsulated in microcapsule, and wherein middle and low boiling point solvent such as xylene, cyclohexane have volatile It is strong and has certain toxicity problems. There may be leakage pollution problems during the use of the tablet, which is harmful to human health. CN201010266783.X uses relatively environmentally friendly white mineral oil as the core material solvent, but the white mineral oil has a low specific gravity. Capsules are easy to float, which is not conducive to the encapsulation of microcapsules and later cleaning and collection. At the same time, due to the low specific gravity of the solvent, the magnetic particles are easy to settle in it, resulting in unstable imaging. In addition, this technology is the same as CN95115366. , CN00109809.8, only a single use of the complex coacervation method is used to wrap the oil phase core material, because gelatin and gum arabic belong to natural polymer materials, which are easy to degrade, resulting in insufficient stability of the microcapsule wall strength. It is easy to be damaged; CN200810126687.8 adopts the water-in-oil interface method to prepare microcapsules, although the reaction speed is fast, but because a large amount of solvent is used in the dispersed phase, the production cost is high and there is pollution; CN201310011473.7 uses the sharp hole-coagulation bath method , the preparation process is simple, and the microcapsule molding speed is fast, but because of the drop-by-drop injection molding, the preparation efficiency is low, and it is difficult to mass-produce and apply

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