A kind of preparation method of polyaluminum calcium phosphate

Abstract

The invention discloses a preparation method of polymerized calcium aluminium phosphate. The preparation method comprises the steps of: by using weak acid salts, hydroxides or oxides of aluminium and weak acid salts, hydroxides or oxides of calcium as raw materials, firstly carrying out coordination reaction of the raw materials and equivalent phosphoric acid so as to prepare aluminium dihydrogen phosphate and calcium dihydrogen phosphate mixed slurry, and then carrying out polymerization reaction of the mixed slurry so as to prepare the polymerized calcium aluminium phosphate. The preparation method has the advantages that the pH value of the product is increased by introducing weakly-alkaline aluminium and calcium, a white pigment product with relatively high anti-rust performance and low heavy metal content is obtained with relatively low cost, the problem that pigment containing aluminium triphosphate easily causes resin colloidizing when being used in coating, especially in water-based coating is better solved, and the polymerized calcium aluminium phosphate has broad market prospect.

Description

technical field [0001] The invention relates to the technical field of inorganic pigments, in particular to a preparation method of polyaluminum calcium phosphate. Background technique [0002] As we all know, traditional anti-rust pigments such as lead and chromium used in the paint industry are highly toxic. In addition, the three wastes produced in the production process of lead and chromium pigments, the dust produced in the paint making process, the gas emitted during welding and cutting after metal painting, and the toxic paint film after the coating is damaged, etc. will all harm the human body and the environment. cause serious harm and pollution. Therefore seeking non-toxic or low-toxic anti-rust pigments has become the consensus of people. Aluminum tripolyphosphate, which has been widely used in the market in recent years, is the leader of this kind of non-toxic and pollution-free anti-rust pigment. Since aluminum dihydrogen tripolyphosphate is a Lewis solid aci...

AI Technical Summary

Problems solved by technology

The biggest disadvantage of this post-modification process is that the modification is insufficient, and the local acidity value of the pigment is still high, resulting in a decrease in the storage stability of the paint, a decrease in the quality of the paint film, and affecting the construction of the paint.

This is especially obvious in water-based coatings, and it also limits the application of environmentally friendly and non-toxic pigments such as aluminum tripolyphosphate in water-based anti-corrosion coatings

[0003] At present, the phosphate composite antirust pigments on the market at home and abroad mainly include composite zinc phosphate and modified zinc phosphate, aluminum tripolyphosphate and modified aluminum tripolyphosphate, zinc phosphomolybdate, zinc iron phosphate and phosphite Composite pigments, etc., but there is no report about polyaluminum calcium phosphate as an antirust pigment

Moreover, the main material elements of terminal products in foreign developed countries are phosphorus, aluminum, and zinc. The cost of these raw materials is generally high, which limits their popularization and application.