Novel reusable water writing paper

Abstract

The invention relates to a novel reusable water writing paper which is prepared from a color developing component and a substrate. According to the color developing principle of the novel reusable water writing paper, a water photochromic dye is used as the color developing component; after the paper is wetted, molecular configuration or comformation change is caused to further cause obvious color change to develop color; after water is dried, a molecular structure is recovered, and the color fades; different colors can be shown through change of molecular substituent groups. When people write on the paper, handwriting is clear and is not easily diffused. The surface of the paper is smooth and is reusable; the paper, people can do writing and drawing exercises on the paper with a writing brush and can also write on the paper with a pen. In addition, no ink printing can be realized by spraying water. Due to the special response to water, the water writing paper can be applied to humidity detecting cards, safety and anti-counterfeiting field and the like.

Description

technical field [0001] The invention relates to a novel reusable water writing paper which develops color when exposed to water. It belongs to the field of reusable writing and printing materials. Background technique [0002] The waste of one-time writing or printing paper is serious. From the perspective of protecting the environment and reusing resources, the recycling of paper is particularly important. There are also a large number of reusable water-colored water writing papers on the market at present, but the existing water writing papers are all composed of paper base, carbon black layer and spray white layer or directly composed of dark base paper and spray white layer. For example, Chinese patent CN2628572Y discloses a reusable water writing paper. However, they are all based on the fact that the sprayed white layer becomes transparent when it meets water, and the carbon black layer or the color of the dark base paper realizes the physical property change of wate...

AI Technical Summary

Problems solved by technology

However, they are all based on the fact that the sprayed white layer becomes transparent when it meets water, and the carbon black layer or the color of the dark base paper realizes the physical property change of water writing. The water writing paper prepared by this method shows mostly black color, contrast and resolution. The rate is not high, and the scope of application is limited to calligraphy and painting exercises