阅读说明：本技术 一种硅酸铝-白炭黑复合填料的制备方法 (Preparation method of aluminum silicate-white carbon black composite filler ) 是由 任立荣 曾志恩 田明 徐钰兴 徐功智 黄宇 刘安基 黄永生 罗明辉 谢志雄 王锦 于 2020-05-07 设计创作，主要内容包括：本发明公开了一种硅酸铝-白炭黑复合填料的制备方法。先将水和硅化合物加入到反应釜中,搅拌升温至60～90℃后,同时添加硅化合物和酸化剂进行反应,反应溶液pH＝8.0～11.0；再经熟化后加入铝化合物溶液继续反应,并加入沉淀剂,生成硅铝酸钠凝胶后继续熟化得到硅铝酸钠纳米粒子悬浮液；再往悬浮液中加入硅化合物,搅拌使pH＝8～11,升温至60～90℃,得到二氧化硅反应底料后同时添加硅化合物和酸化剂1～2h,使维持pH＝8～11,得到纳米硅铝酸钠-白炭黑复合填料的浆料后停加硅化合物,继续添加酸化剂至pH＝3.0～6.0后停止添加,获得纳米硅铝酸钠-白炭黑复合填料的悬浮液；将悬浮液经过滤、洗涤、高温快干获得消光效率高、分散性好、贮存稳定的纳米硅铝酸钠内核与二氧化硅包覆外壳复合填料。(The invention discloses a preparation method of an aluminum silicate-white carbon black composite filler. Adding water and a silicon compound into a reaction kettle, stirring and heating to 60-90 ℃, and simultaneously adding the silicon compound and an acidifier for reaction, wherein the pH value of a reaction solution is 8.0-11.0; then, after curing, adding an aluminum compound solution for continuous reaction, adding a precipitator to generate sodium aluminosilicate gel, and then, continuously curing to obtain a sodium aluminosilicate nanoparticle suspension; adding a silicon compound into the suspension, stirring to ensure that the pH value is 8-11, heating to 60-90 ℃, obtaining a silicon dioxide reaction bed charge, simultaneously adding the silicon compound and an acidifying agent for 1-2 hours, keeping the pH value at 8-11, obtaining slurry of the nano sodium aluminosilicate-white carbon black composite filler, stopping adding the silicon compound, continuing adding the acidifying agent until the pH value is 3.0-6.0, and stopping adding to obtain suspension of the nano sodium aluminosilicate-white carbon black composite filler; filtering, washing and quick drying the suspension at high temperature to obtain the nano sodium aluminosilicate core and silica coated shell composite filler with high extinction efficiency, good dispersibility and stable storage.)

1. A preparation method of aluminum silicate-white carbon black composite filler is characterized by comprising the following steps: the prepared product is a composite filler formed by a nano sodium aluminosilicate core and a silicon dioxide coated shell, and the operation steps are as follows:

A. synthesis of nano sodium aluminosilicate kernel by homogeneous precipitation method

A1, adding bottom water and a silicon compound into a reaction kettle, wherein the volume mixing ratio of the bottom water to the silicon compound is (10-20): (0.05-0.2), introducing steam under the condition of stirring, and heating to 60-90 ℃; simultaneously adding a silicon compound and an acidifying agent for reaction, wherein the adding time of the silicon compound and the acidifying agent is 20-40 min, the concentration of the silicon compound is 0.5-1.0 mol/L, the flow rate is 2.5-8.0 mL/min, the mass fraction of the acidifying agent is 18.0-50.0%, and the flow rate is 0.5-5.5 mL/min, so that the pH of a reaction solution is controlled to be 8.0-11.0;

a2, adding an aluminum compound solution after curing for 10-30 min, continuously reacting the aluminum compound with the flow rate of 1.0-5.0 mL/min and the mass fraction of 20-50%, adding for 30-60 min, adding a water-soluble alkaline solution as a precipitator to generate sodium aluminosilicate gel, and curing for 1-2 h to obtain a sodium aluminosilicate nanoparticle suspension;

B. silica coated shell synthesized by precipitation method

B1, adding a silicon compound into the sodium aluminosilicate nanoparticle suspension prepared in the step A2, wherein the volume mixing ratio of the silicon compound to the bottom water in the step A1 is (0.1-0.5): (10-20), uniformly stirring to ensure that the pH value in the reaction kettle is 8-11, introducing steam, heating to 60-90 ℃, and obtaining a silicon dioxide reaction bottom material, wherein the concentration of the silicon compound is 0.5-1.0 mol/L;

b2, adding a silicon compound and an acidifying agent into the reaction substrate of the step B1 simultaneously to maintain the pH of the reaction medium at 8-11, wherein the flow rate of the silicon compound is 2.5-8.0 mL/min, and the concentration of the silicon compound is 0.5-1.0 mol/L; the flow rate of the acidifying agent is 0.5-5.5 mL/min, and the mass fraction is 50% -98%; the charging time of the silicon compound and the acidifying agent is 1-2 h; obtaining slurry of the nano sodium aluminosilicate-white carbon black composite filler;

b3, stopping adding the silicon compound, continuing to add the acidifying agent into the slurry of the nano sodium aluminosilicate-white carbon black composite filler prepared in the step B2 until the pH value of a reaction medium is 3.0-6.0, and stopping adding the acidifying agent to obtain a suspension of the nano sodium aluminosilicate-white carbon black composite filler;

and B4, filtering, washing and quickly drying the suspension of the nano sodium aluminosilicate-white carbon black composite filler prepared in the step B3 at high temperature of 240-340 ℃ to obtain an aluminum silicate-white carbon black composite filler product.

2. The method for preparing the aluminum silicate-white carbon black composite filler as claimed in claim 1, which is characterized in that: the silicon compound is any form of silicate including potassium silicate, sodium silicate, ethyl silicate.

3. The method for preparing the aluminum silicate-white carbon black composite filler as claimed in claim 1 or 2, which is characterized in that: the silicon compound is sodium silicate.

4. The method for preparing the aluminum silicate-white carbon black composite filler as claimed in claim 1, which is characterized in that: the acidifying agent is any form of acid including sulfuric acid, nitric acid, oxalic acid.

5. The method for preparing the aluminum silicate-white carbon black composite filler as claimed in claim 1 or 4, which is characterized in that: the acidifying agent is sulfuric acid.

6. The method for preparing the aluminum silicate-white carbon black composite filler as claimed in claim 1, which is characterized in that: the aluminum compound is any form of water-soluble aluminum compound including aluminum chloride, potassium aluminum sulfate dodecahydrate, aluminum sulfate.

7. The method for preparing the aluminum silicate-white carbon black composite filler as claimed in claim 1 or 6, which is characterized in that: the aluminum compound is aluminum sulfate.

8. The method for preparing the aluminum silicate-white carbon black composite filler as claimed in claim 1, which is characterized in that: the water-soluble alkaline solution precipitant is any form of water-soluble alkaline solution including urea, ammonia water, and sodium carbonate.

9. The method for preparing the aluminum silicate-white carbon black composite filler as claimed in claim 1, which is characterized in that: the water-soluble alkaline solution precipitant is ammonia water.

10. The method for preparing the aluminum silicate-white carbon black composite filler as claimed in claim 1, 2, 4, 6 or 8, which is characterized in that: the synthesis reaction is carried out under stirring.

Technical Field

The invention relates to a preparation method of a powdery inorganic material, in particular to a preparation method of a nano aluminum silicate-white carbon black composite filler.

Background

The aluminum silicate, also called sodium aluminosilicate, is a functional silicate product, has very small primary particle size (1-10 um), extremely fine particles and excellent suspension property, and is a composite powder material generated in situ by sodium salts of silicic acid and aluminic acid. The sodium aluminosilicate is white powder with an apparent special structure, the performance of the sodium aluminosilicate has certain similarity in many application fields compared with expensive titanium dioxide, and the sodium aluminosilicate is doped into the emulsion paint, so that 15-25% of the titanium dioxide can be saved, and the use cost is greatly saved; because of the developed pore structure, strong moisture absorption and ultrahigh whiteness, the pesticide has been used in pesticides instead of silicon dioxide in recent years, and the effect is good; in addition, due to the advantages of easy obtainment of production raw materials, low cost and the like, the polyurethane-modified polypropylene composite material has good market prospect in the industries of coatings, paints, adhesives, papermaking, rubber and plastics and the like.

The precipitated hydrated silicon dioxide is also called white carbon black, and is a non-toxic, tasteless and pollution-free non-metallic material. White carbon black is an important chemical raw material and is widely applied to various fields of rubber, silicon rubber, paint, coating, high-grade daily cosmetics and the like. When being applied to paint, the silicon dioxide has the characteristics of stable chemical property, high extinction efficiency, good transparency, easy addition, stable storage and the like.

In the existing preparation process, the silica flatting agent generally adopts a sol-gel method, and the gelling mode adopts the steps of firstly adding water glass base solution, stirring and adding an acidifying agent to form the gel. The concentration of the bottom alkali is gradually changed from high to low in the reaction process, the pH value of the reaction system is correspondingly changed, and the generated silica primary particles are uneven in size and serious in agglomeration phenomenon, so that the pore volume is small, the pore size distribution is wide, the extinction efficiency is low, the dispersibility is poor and the like. Therefore, it is necessary to develop silica filler meeting the increasing economic and environmental requirements by improving the existing precipitated silica production process, i.e., silica product having high extinction efficiency, good dispersibility and storage stability.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a preparation method of an aluminum silicate-white carbon black composite filler with high extinction efficiency, good dispersibility and stable storage.

In order to realize the purpose, the product prepared by the preparation method of the aluminum silicate-white carbon black composite filler is the composite filler consisting of a nano sodium aluminosilicate core and a silicon dioxide coated shell, and the operation steps are as follows:

A. synthesis of nano sodium aluminosilicate kernel by homogeneous precipitation method

A1, adding bottom water and a silicon compound into a reaction kettle, wherein the volume mixing ratio of the bottom water to the silicon compound is (10-20): (0.05-0.2), introducing steam under the condition of stirring, and heating to 60-90 ℃; simultaneously adding a silicon compound and an acidifying agent for reaction, wherein the adding time of the silicon compound and the acidifying agent is 20-40 min, the concentration of the silicon compound is 0.5-1.0 mol/L, the flow rate is 2.5-8.0 mL/min, the mass fraction of the acidifying agent is 18.0-50.0%, and the flow rate is 0.5-5.5 mL/min, so that the pH of a reaction solution is controlled to be 8.0-11.0;

a2, adding an aluminum compound solution after curing for 10-30 min, continuously reacting the aluminum compound with the flow rate of 1.0-5.0 mL/min and the mass fraction of 20-50%, adding for 30-60 min, adding a water-soluble alkaline solution as a precipitator to generate sodium aluminosilicate gel, and curing for 1-2 h to obtain a sodium aluminosilicate nanoparticle suspension;

B. silica coated shell synthesized by precipitation method

B1, adding a silicon compound into the sodium aluminosilicate nanoparticle suspension prepared in the step A2, wherein the volume mixing ratio of the silicon compound to the bottom water in the step A1 is (0.1-0.5): (10-20), uniformly stirring to ensure that the pH value in the reaction kettle is 8-11, introducing steam, heating to 60-90 ℃, and obtaining a silicon dioxide reaction bottom material, wherein the concentration of the silicon compound is 0.5-1.0 mol/L;

b2, adding a silicon compound and an acidifying agent into the reaction substrate of the step B1 simultaneously to maintain the pH of the reaction medium at 8-11, wherein the flow rate of the silicon compound is 2.5-8.0 mL/min, and the concentration of the silicon compound is 0.5-1.0 mol/L; the flow rate of the acidifying agent is 0.5-5.5 mL/min, and the mass fraction is 50% -98%; the charging time of the silicon compound and the acidifying agent is 1-2 h; obtaining slurry of the nano sodium aluminosilicate-white carbon black composite filler;

b3, stopping adding the silicon compound, continuing to add the acidifying agent into the slurry of the nano sodium aluminosilicate-white carbon black composite filler prepared in the step B2 until the pH value of a reaction medium is 3.0-6.0, and stopping adding the acidifying agent to obtain a suspension of the nano sodium aluminosilicate-white carbon black composite filler;

and B4, filtering, washing and quickly drying the suspension of the nano sodium aluminosilicate-white carbon black composite filler prepared in the step B3 at high temperature of 240-340 ℃ to obtain an aluminum silicate-white carbon black composite filler product.

The above synthesis reactions were all carried out under stirring.

The silicon compound is any form of silicate including potassium silicate, sodium silicate, ethyl silicate, preferably sodium silicate.

The acidifying agent is any form of acid including sulfuric acid, nitric acid, oxalic acid, preferably sulfuric acid.

The aluminium compound is any form of water soluble aluminium compound including aluminium chloride, potassium aluminium sulphate dodecahydrate, aluminium sulphate, preferably aluminium sulphate.

The water-soluble alkaline solution precipitant is any form of water-soluble alkaline solution including urea, ammonia water, sodium carbonate, preferably ammonia water.

The preparation method of the aluminum silicate-white carbon black composite filler comprises the steps of introducing a nano sodium aluminosilicate core into a silicon dioxide structure to construct a core-shell structure of the nano sodium aluminosilicate and the silicon dioxide, so that the density of the aluminum silicate core is higher than that of a silicon dioxide coated shell; the thickness and porosity of the silicon dioxide coated shell are higher than those of the aluminum silicate inner core, so that the pore volume is increased; the superfine and gridding structure of the sodium aluminosilicate nano inner core has good suspension property and prevents the solid from settling, thereby reducing the aggregation degree of the white carbon black particles; meanwhile, the nano sodium aluminosilicate kernel has an extinction effect, and can greatly improve the extinction efficiency of the composite filler when being used as an extinction 'extender' of the aluminum silicate-white carbon black composite filler.

The aluminum silicate-white carbon black composite filler product obtained by the preparation method of the aluminum silicate-white carbon black composite filler partially replaces titanium dioxide, the dry film covering power of the aluminum silicate-white carbon black composite filler product is not changed, and the whiteness of paint can be improved. If the amount of the titanium dioxide is not changed, the covering power of a dry film is obviously improved, and the whiteness is greatly improved.

The aluminum silicate-white carbon black composite filler obtained by the preparation method of the aluminum silicate-white carbon black composite filler is not limited to be applied to a delustering agent, and can be further applied to products such as rubber, silicon rubber and the like.

Detailed Description

The contents and characteristics of the preparation method of the aluminum silicate-white carbon black composite filler of the present invention are further described in detail with reference to the specific embodiments below.