Titanium dioxide for extinction of chinlon chemical fibers and preparation method of titanium dioxide

Abstract

The invention relates to composite titanium dioxide used as a nylon chemical fiber delustering agent, which is formed by mixing a meso-porous silicon coated superfine titanium dioxide main component and an amorphous silicon core aluminum-based titanium dioxide auxiliary component, and the mixed material is subjected to surface treatment. Wherein the weight ratio of the meso-porous silicon coated ultrafine titanium dioxide is not less than 50wt%; the particle size D90 of the meso-porous silicon coated ultrafine titanium dioxide is less than or equal to 0.3 mu m; d90 of the amorphous silicon-core aluminum-based titanium dioxide is less than or equal to 0.45 mu m. The particle size range of the composite titanium dioxide provided by the invention corresponds to about half of the wavelength of visible light, and the composite titanium dioxide has significantly improved particle uniformity and matting performance.

Description

technical field [0001] The invention relates to the technical field of nylon chemical fiber matting agents, in particular to a composite titanium dioxide used as a nylon matting agent and a preparation process thereof. Background technique [0002] Nylon chemical fiber, also known as polyamide fiber or nylon, is a textile fiber with excellent mechanical properties, but ordinary nylon fiber strongly reflects light due to the orderly arrangement of molecules, resulting in dazzling luster and high transparency. In order to solve this problem, functional inorganic powders such as anatase titanium dioxide, that is, a matting agent for nylon fibers, are usually added to synthetic fibers. [0003] Titanium dioxide is a chemical fiber additive with good comprehensive properties such as shading power and whiteness on the market. However, the low-cost anatase titanium dioxide has photocatalytic activity, which will degrade polyamide molecules and cause the aging problem of nylon fiber...

AI Technical Summary

Problems solved by technology

[0003] Titanium dioxide is currently a chemical fiber additive with good comprehensive properties such as shading power and whiteness on the market, but the low-cost anatase titanium dioxide has photocatalytic activity, which will degrade polyamide molecules and cause the aging of nylon fibers, so it needs to be coated Modification to obtain more stable and better dispersible products

[0011] 1) In the prior art, the coating method of adding inorganic silicon sources or aluminum salts is used. In order to form a dense layer, multiple coating operations are often used (in order to cover the photocatalytic active center of titanium dioxide, the compactness and high density of the coating film are too much pursued. Integrity), and the use of high concentrations of metal salts not only leads to excessive particle size, but also easily forms a large amount of alumina and silica particle impurities (non-film-forming coating) in the solution, and also leads to a large amount of metal salt wastewater (the inorganic treatment agent commonly used in the prior art is water glass namely sodium silicate, sodium aluminate, aluminum sulfate, zirconium sulfate etc.), reclaims difficulty, and processing cost is high

[0012] 2) When the existing technology adopts organic molecular modification, it is often directly physically adsorbed on the surface of titanium dioxide particles, the binding force is weak, the molecules are easy to desorb from the surface, and the effect of improving the compatibility between the titanium dioxide matting agent and the chemical fiber cannot be achieved

[0013] 3) There are obvious disadvantages in reducing the photocatalytic activity of titanium dioxide through one or more dense inorganic layers: it is well known in the art that titanium dioxide acts as a matting agent by scattering visible light, and multiple coatings or multiple depositions will not only make Titanium dioxide particles are completely coated and cannot exert their performance, and their particle size increases significantly (even to about 1 micron or higher), which seriously reduces their matting ability

In its preferred embodiment, it can only obtain titanium dioxide with a particle size of about 0.3 microns, and cannot obtain titanium dioxide with a lower particle size; after coating, the particle size is more than 0.4 microns

In addition, particles below 0.3 microns are not easy to wash and agglomerate, and the filtration loss is large. This patent cannot avoid this common defect (ultrafine particle size and filtration loss are interrelated, and usually cannot be taken into account, that is: the finer the particle diameter, the greater the washing and filtration loss)

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