Low-viscosity iron oxide yellow

Abstract

The invention discloses low-viscosity iron oxide yellow. A preparation method of the iron oxide yellow comprises the steps that ferrous sulfate and sodium hydroxide are reacted at the temperature of 25-35 DEG C to prepare ferric oxide yellow seed crystal, the prepared seed crystal is placed into a high-pressure reaction kettle, meanwhile, the temperature is increased to 70 DEG C, at the moment, air pressure in the reaction kettle is the same as that of the outside world, a sodium hydroxide solution with the concentration of 8-12 mol/L is added when the temperature reaches 70 DEG C, the added alkaline liquid amount is determined based on the pH value, adding of alkaline liquid is stopped when pH reaches 3.8-4.2, a valve of the high-pressure reaction kettle is turned off after the pH reaches the specific value, the high-pressure reaction kettle is pressurized through a high-pressure air pump, air is continuously pumped into the reaction kettle from the bottom through the high-pressure pump in the reaction process, meanwhile, air is exhausted from the top of the reaction kettle to ensure that sufficient oxygen participates in reaction, the system air pressure is controlled to be about 1.2-1.7 MPa, the reaction temperature is 70 DEG C, the reaction time is controlled to be 12-14 h, and finally rinsing, suction filtration, drying and smashing are carried out, so that the low-viscosity iron oxide yellow is obtained.

Description

technical field [0001] The invention relates to a low-viscosity iron oxide yellow pigment, in particular to the preparation of low-viscosity iron oxide yellow by controlling conditions such as pressure, pH value, temperature and reaction time in the reaction process. technical background [0002] Iron oxide yellow, also known as iron oxyhydroxide, its molecular formula is FeOOH or Fe2O3·H2O, it is yellow powder, its particle shape is needle-like, it has high coloring power, hiding power, and it is non-toxic and harmless, and is environmentally friendly Type inorganic pigment, its light fastness reaches 6-7 level. Iron oxide yellow pigments are widely used in building materials, coatings, paints, plastics, rubber, electronics, industrial catalysts, tobacco, cosmetics and other industries. [0003] Due to the different particle shape and surface chemical properties of ordinary iron oxide yellow, its viscosity is high, and there are some problems in the coating application pro...

AI Technical Summary

Problems solved by technology

[0007] At present, relevant literature reports at home and abroad show that the viscosity of iron oxide yellow can be improved by changing the surface charge of iron oxide yellow particles or reducing the aspect ratio of iron oxide yellow particles. In China, Nantong Baoju Pigment Company has published a patent number of ZL201310277999 .X's patent of 'a method for reducing the viscosity of iron oxide yellow pigment' is to improve the viscosity of iron oxide yellow by changing the charge on the surface of iron oxide yellow particles. The effect is ideal, but there is still room for improvement; and Zhejiang United Pigment disclosed The patent of the application number 201410767118.7 "a low-viscosity iron oxide yellow pigment" is based on the principle of destroying the shape of some iron oxide yellow pigment particles through grinding with steel balls, but not reducing the aspect ratio of all iron oxide yellow particles as a whole. Not significant enough

Images