Preparation method of silicon dioxide used for tooth paste

Abstract

The invention discloses a preparation method of silicon dioxide used for tooth paste. According to the invention, a two-stage alkali-adding method is adopted, and the method comprises the steps that: a certain amount of sodium silicate water solution and a certain amount of sulfuric acid water solution are prepared firstly; the sulfuric acid water solution is added into a reaction kettle at ordinary temperature, wherein the adding amount is 50% of needed sulfuric acid; the sodium silicate water solution is added until the pH reaches 7-8; the temperature is increased to 70-80 DEG C; mixing is performed for 1-2 h; the rest sodium silicate solution is added into the reaction slurry; the temperature is increased to 70-80 DEG C; the sulfuric acid water solution is added until the pH reaches 4-5; the heat temperature is preserved for 20-30 min; water washing, drying and smashing are conducted to obtain tooth-paste-used silicon dioxide. The silicon dioxide has proper abrasion amount and good thickening property.

Description

technical field [0001] The invention relates to a preparation method of silicon dioxide for toothpaste Background technique [0002] Silicon dioxide mainly plays two roles in toothpaste, one is to play the role of friction agent, and the other is to play the role of thickener. With the improvement of people's material and cultural level, transparent silica toothpaste with suitable abrasiveness has been favored by people. At present, the main production methods of silica for toothpaste include gel method and precipitation method. Other products produced by gel method It is mainly used as a friction agent. The silicon dioxide prepared by the precipitation method is mainly used as a thickener. In the production of transparent toothpaste, the friction agent and the thickener must be added separately to make the toothpaste not only have a suitable amount of abrasion but also have a gel-like texture. appearance characteristics. Due to the addition of silicon dioxide in two step...

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Problems solved by technology

Due to the addition of silicon dioxide in two steps, the dust flying in the production process and the increase of labor costs are caused. Adding a single type of silicon dioxide alone, the abrasion amount and thickening performance of the toothpaste abrasive can not meet the use requirements at the same time, as disclosed in the patent CN101417808A "A Preparation Method of Silicon Dioxide Thickener for Toothpaste" adopts the following steps, (1) Dilute the alkali metal silicate and acidulant into 3-10% and 10-30% dilute solutions, dilute the diluted The final alkali metal silicate solution and acidifying agent solution are heated to 60-100°C; (2) Add the alkali metal silicate dilute solution and sodium monofluorophosphate with a molar ratio of 1-10% into the reactor until the pH reaches 7-9; (3) Add acidifying agent and alkali metal solution in parallel, maintain the reaction temperature at 60-100°C, control the adding speed of acidifying agent solution and alkali metal silicate solution respectively, so that the pH in the kettle is always maintained at PH7- 9. After adding the dilute solution of alkali metal silicate, age for 5-10mins, then adjust the pH in the kettle to 3-6 through the acidifier dilute solution, and continue to age for 20-40mins; (4) Separate the above product through liquid-solid The equipment is filtered and washed, and the filter cake is flowed through a colloid mill, and finally dried by spray drying to obtain a silica thickener

But the silicon dioxide prepared by the above method plays the role of thickener in toothpaste to prevent heavier abrasives from settling, and cannot be used as abrasive in toothpaste. Patent CN1070891A introduces "a toothpaste abrasive dioxide The preparation method of silicon" is characterized in that: the BET specific surface area is 100-450m 2 / g, the average particle size is 5-15μm, the plastic abrasion value is 16-26, and the average pore diameter is 2-12μm. The silica prepared by this method can only be used as a friction agent

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