Grammite raphioid fibre crystal-nano calcium carbonate micro-nano composite powder material and production method

Abstract

The invention relates to a surface modified product of an acicular wollastonite crystal and a production method thereof. The product is micro-nano composite powder by coating a nanometer calcium carbonate crystal on the surface of the acicular wollastonite fiber crystal. The method comprises the following steps: firstly, preparing an active lime milk solution and an acicular wollastonite fiber solution; compounding the two solutions into a suspension; adding a crystalline directing agent to the suspension and filling CO2 gas for a coating reaction so that the nanometer calcium carbonate crystal gradually grows on the surface of an acicular aedelforsite fiber, and the micro-nano composite powder by coating a nanometer calcium carbonate crystal on wollastonite is obtained; and coating a layer of coupling agent on the surface of the micro-nano composite powder to obtain the acicular wollastonite fiber crystal-nanometer calcium carbonate crystal-coupling agent composite powder material. The product keeps the superior characteristics of the acicular wollastonite crystal and the nanometer calcium carbonate crystal, improves the surface energy and the chemical activity of wollastonite composite particles and can be well stuck with organic polymers so as to form a favorable interface and improve the bonding force between fillings and basal bodies, such as plastics, pulp, and the like.

Description

technical field [0001] The invention relates to an inorganic mineral product and a processing method thereof, in particular to a surface-modified product of acicular wollastonite and a production method thereof. Background technique [0002] Wollastonite is an important inorganic mineral product, a kind of acicular metasilicate mineral, and acicular wollastonite is a relatively scarce natural resource. Its chemical formula is CaSiO 3 , There are two variants of high temperature and low temperature, and the so-called wollastonite refers to the high temperature variant. It is generally in the form of fibrous, needle-like or radial aggregates, and its length-to-diameter ratio is generally 5:1. In the existing crushing technology, its length-to-diameter ratio can reach 15-20:1. Wollastonite has the characteristics of high electrical resistance, low dielectric constant, low hygroscopicity, low viscosity, high oil absorption value and fast dispersion. The filling performance is...

AI Technical Summary

Problems solved by technology

[0005] The technical solution of this patent is to coat the nano-powder material on the surface of the micron crystal. It is a physical coating process, and no chemical reaction occurs between various substances. The disadvantage of this method is that the particle size of two kinds of particles is required. To match, it is generally believed that the particle size ratio of large and small particles should be greater than 1 to 2 orders of magnitude, and small particles must be nano-scale powders, otherwise the combination of the two will not be strong enough

Therefore, when the above-mentioned products are used as fillers in polymer matrices such as plastics and rubber, under the action of strong shear stress, this micro-nano composite powder material is easily dispersed into the original simple nano-crystal secondary particles and Micron crystals, thus losing the excellent properties of micro-nano composite powder materials

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