A zirconium silicate-encapsulated low-valent ion composite doped gamma-ce2s3 red pigment and its preparation method

Abstract

The invention discloses a zirconium silicate-coated low-valence ion co-doping gamma-Ce2S3 red pigment which is composed of low-valence ion co-doping gamma-Ce2S3 red pigment powder and a zirconium silicate transparent shell coating the surface of the low-valence ion co-doping gamma-Ce2S3 red pigment powder, wherein in the low-valence ion co-doping gamma-Ce2S3 red pigment powder, the ion valence ofthe doping ion M is 2, and at least two doping ions exist according to a molar ratio of 2(1-x):3x between Ce<3+> and M(total), where x is greater than 0 and less than or equal to 0.1. The invention also discloses a preparation method of the gamma-Ce2S3 red pigment. According to the zirconium silicate-coated low-valence ion co-doping gamma-Ce2S3 red pigment disclosed by the invention, the gamma-Ce2S3 crystal structure is stabilized internally through a way of low-valence ion co-doping while the gamma-Ce2S3 is coated externally with zirconium silicate which is stable at high temperature, therebyremarkably improving the high-temperature stability of the gamma-Ce2S3 red pigment and significantly expanding the application field of the gamma-Ce2S3 red pigment. The preparation method disclosed by the invention has the advantages that the technology is simple and easy to operate, the influence factors are easy to control, the production cost is low and the promotion and application are facilitated.

Description

technical field [0001] The invention relates to the technical field of inorganic pigments, in particular to a zirconium silicate-wrapped γ-Ce 2 S 3 Red pigment and its preparation method. Background technique [0002] Red pigments are divided into two categories: organic red pigments and inorganic red pigments. Compared with organic red pigments, inorganic red pigments have better hiding power, heat resistance, light resistance and weather resistance, so they are widely used in some special fields. However, most of the currently used inorganic red pigments contain toxic heavy metal elements such as cadmium, lead, and mercury. With the increasing awareness of environmental protection worldwide, it is imminent to develop new bright red pigments that are non-toxic and have good color development. [0003] γ~Ce 2 S 3 The pigment is bright red, stable in color, strong in hiding power, resistant to ultraviolet radiation, safe and non-toxic, and has become the first choice to r...

AI Technical Summary

Problems solved by technology

At present, more studies are made on SiO 2 , ZrO 2 Wrapped type γ~Ce 2 S 3 Pigment, among them, SiO 2 The wrapping is relatively mature, and the wrapping layer is relatively dense, but only γ~Ce 2 S 3 The high temperature stability of ZrO is increased to 550°C; ZrO 2 There are problems such as insufficient coating thickness and incomplete coating in the package

On the other hand, due to γ~Ce 2 S 3 Belonging to Cubic Th 3 P 4 type structure, there are cation vacancies in the lattice, and the vacancies form a twisted S in the cubic crystal structure 4 Tetrahedral voids, resulting in γ~Ce 2 S 3 The crystal structure is very unstable, and it is easy to reverse and transform into β phase under high temperature, thus losing the red color

Therefore, the problem of crystal structure stability cannot be solved essentially only by simple encapsulation. At present, although ion doping is also used to achieve lattice stability, research has found that although single ion doping can achieve lattice stability, it is easy to so that γ~Ce 2 S 3 The electronic transition energy of the pigment f→d changes, so that the absorption spectrum changes, and finally the red color is no longer displayed

[0005] For this reason, neither simple encapsulation nor single ion doping in the prior art can well solve the problem of γ~Ce 2 S 3 Problems of high temperature stability and its limitations in high temperature applications

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