Preparation method of nanometer silica polyether (ester) polyol dispersion for modifying polyurethane

Abstract

The invention provides a preparation method of a nanometer silica polyether (ester) polyol dispersion for modifying polyurethane. The method adopting precipitation and extraction combination comprises the following steps: preparing a nanometer silica dispersion by using alkali metal silicate under acid catalysis or other strong acidic and strong acid weak alkali salt double hydrolysis conditions, carrying out wrapping modification through a coupling agent, adding a corresponding strong acid strong alkali salt until the obtained solution is supersaturated, extracting nanometer silica from the obtained aqueous solution by using a low boiling point solvent, adding polyether (ester) polyol, mixing, and carrying out reduced pressure distillation at 80DEG C under an absolute pressure of below 0.010MPa to remove the low boiling point solvent and obtain the uniform nanometer silica polyether (ester) polyol dispersion. The dispersion can be used as a polyurethane modifier to improve the hardness, the toughness, the compactness, the antifriction property and the like of a film. The preparation method of the nanometer silica dispersion has the advantages of simplicity, cheap and easily available raw materials, low cost, and suitableness for large-scale industrial production.

Description

technical field [0001] This patent relates to a method for preparing a modified polyurethane nano-silica polyether (ester) polyol dispersion. It specifically relates to the preparation of nano silicon dioxide polyether (ester) polyol dispersion. Background technique [0002] Nano silica is an amorphous white powder, which is a non-toxic, odorless and non-polluting non-metallic functional material. nano-SiO 2 It is currently the inorganic nanomaterial with the largest industrial output and the most widely used. The primary particle size is generally between 10nm and 60nm, the relative density is 2.319-2.653, and the melting point is 1750°C. nano-SiO 2 The molecular state is a three-dimensional chain structure, and there are residual bonds and hydroxyl groups in different bonding states on the surface, and it deviates from the stable silicon-oxygen structure due to oxygen deficiency, so nano-SiO 2 The molecular formula can be expressed as SiO 2-x (x0.4~0.8). nano-SiO 2 ...

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Problems solved by technology

Therefore, so far, there have been no reports of a nano-silica monomer dispersion that can be highly uniformly dispersed in the form of primary particles in a monomer medium and can be stored stably for a long time. The nano-silica dispersion prepared by this patent No need to pass through nano-silica powder, avoiding agglomeration between nano-silica particles, nano-silica can be uniformly dispersed in polyether (ester) polyol monomers to form a stable dispersion

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