The Study Of Inorganic/Organic Composite Pigments Based On Sepiolite

Organic pigments, which have excellent properties such as good color strength, bright colors, and no toxicity, have started to gradually replace inorganic pigments and are widely used in the fields such as coatings, inks, plastics. But organic pigments have some shortcomings such as poor water dispersion, poor flowing property and poor thermal stability. Therefore, there is need to develop new structures of pigments or modify existing organic pigments to improve its application and performance. At presen the process of develop the new structure of pigments at home and abroad is still relatively complicated and difficult. While It’s a simple and effective method that modify existing organic pigments through modification technology to improve its application and performance. Sepiolite, a kind of natural rich magnesium hydrosilicate, is low price and widely distributed in the world. Its unique nature(such as adsorbability, thermal stability, acid and alkali resistance) make it widely used in the preparation of inorganic/organic composite pigments. In this paper, we modified different types of organic pigments based on sepiolite. And the properties of the modified pigments were compared with the origin.Using kernel and coating methods, we modified rhodamine B based on sepiolite and nano-silica, and successfully prepared composite fluorescent pigments. Proper weight ratio of rhodamine B to sepiolite will not only influence the stability of Sep/Rhb hybrid fluorescent pigments, but also can reduce cost. The stability of Sep/Rhb hybrid fluorescent pigments can be improved by proper ball milling and heating temperature. Owing to the fact that the stability of the Sep/Rhb hybrid fluorescent pigment is not very high, the Sep/Rhb@SiO2 hybrid fluorescent pigments were prepared by coating Sep/Rhb with a layer of SiO2 via silica sol gel method. The TEOS/HAc/H2 O molar ratio is a key factor for preparing Sep/Rhb@SiO2 hybrid fluorescent pigments, Compared with the Sep/Rhb hybrid fluorescent pigments, the stability of Sep/Rhb@SiO2 pigments against acid and alkali, organic solvent, and thermal aging have improved. The BET, ZETA SEM, TEM, FTIR,and XRD data indicate that the Rhb molecules can only be adsorbed onto the external surface, the grooves and the openings of the channels of Sep, but cannot enter the channels.And prove that the presence of silica on the surface of the Sep/Rhb@SiO2 hybrid fluorescent pigments.Using kernel method and ball milling craft, we modified rhodamine B based on sepiolite and successfully prepared Sep/pigment red 21 composite pigments. Sep can not only influence the water dispersion of pigment red 21, but also improve its thermal stability. The zeta data shows that there are strong electrostatic interaction between Sep and pigments, and the weight ratio of pigment red 21 to sepiolite can influence its particle size distribution. For the possible usage in polyving akohol, Sep can also influence its dispersion.