Preparation method of extinction powder special for elastic paint

Abstract

The invention relates to a preparation method of extinction powder special for elastic paint. In a reaction kettle, sodium silicate and water are added, the temperature is increased to 45 DEG C, in the stirring state, sulfuric acid with the concentration being 30% is added, the PH value is regulated to 6-6.5, ammonium hydroxide is added to regulate the PH value to 8.5-9.0, aging is performed for 50 min, then, the temperature is increased to 90 DEG C, meanwhile, sodium silicate and sulfuric acid of the certain concentration are added, aging is performed for 50 min, acid is added till the PH value is 4-5, and filtering, washing, drying and smashing and classification are performed to obtain finished extinction powder. The extinction powder has the advantages of being high in oil absorption value, good in dispersibility, fine in touch, high in transparency and the like, and is reasonable in technology and high in production efficiency.

Description

technical field

[0001] The invention belongs to the preparation technology of powder materials, in particular to a preparation method of silica matting powder for elastic paint matting. Background technique

[0002] Silica micropowder is actually an aggregate of very small silica grains, which is an amorphous white powder. Silica matting powder has the advantages of easy dispersion, good matting performance, little interference with the transparency of the coating film, little effect on the mechanical and chemical properties of the coating film, good suspension in liquid coatings, and high chemical inertness. widely used in.

[0003] The preparation of silica matting powder mainly includes three categories: precipitation method, gel method and gas phase method. Both the gas phase method and the gel method have higher production costs. And the specific surface area produced by different production processes is different. The gel method silica has the characteristics of hig...

Examples

Embodiment 1

[0021] In a 5000L stirred reactor, add 1000L water and 480L sodium silicate solution and stir evenly, raise the temperature to 45°C, and add 30% sulfuric acid dropwise to the solution at a speed of 4L / min under stirring until the pH value is 6.0-7.0, stir for 30 minutes, add 20% ammonia water to adjust the pH value to 8-9, age for 50 minutes, continue to heat up to 90°C, at this temperature, add sodium silicate with a flow rate of 0.55L / min into the reaction kettle at the same time 820L and sulfuric acid, and keep the pH value of the solution at 8-9, continue to age for 50 minutes, continue to add acid until the pH value is 4-5 after the reaction, filter and wash the reaction slurry to obtain a silica filter cake, and re-beaten To form a suspension solution, add polydimethylsiloxane and acrylic acid block polymer to it, then dry, pulverize and classify.

Embodiment 2

[0023] In a 5000L stirred reactor, add 1000L water and 500L sodium silicate solution and stir evenly, raise the temperature to 40°C, and add 30% sulfuric acid dropwise to the solution at a speed of 5L / min under stirring until the pH value is 6.0-7.0, stir for 30 minutes, add 20% ammonia water to adjust the pH value to 8-9, age for 50 minutes, continue to heat up to 85°C, at this temperature, add sodium silicate with a flow rate of 0.55L / min into the reaction kettle at the same time 750L and sulfuric acid, and keep the pH value of the solution at 8-9, continue to age for 50min, continue to add acid until the pH value is 4-5 after the reaction, filter and wash the reaction slurry to obtain a silica filter cake, and re-beaten To form a suspension solution, add polydimethylsiloxane and acrylic acid block polymer to it, then dry, pulverize and classify.

Embodiment 3

[0025] In a 5000L stirred reactor, add 1000L water and 400L sodium silicate solution and stir evenly, raise the temperature to 45°C, add 25% sulfuric acid dropwise to the solution at a speed of 4L / min under stirring until the pH value is 6.0-7.0, stir for 30 minutes, add 20% ammonia water to adjust the pH value to 8-9, age for 50 minutes, continue to heat up to 100°C, at this temperature, add sodium silicate with a flow rate of 0.55L / min into the reaction kettle at the same time 1000L and sulfuric acid, and keep the pH value of the solution at 8-9, continue to age for 50 minutes, continue to add acid until the pH value is 4-5 after the reaction, filter and wash the reaction slurry to obtain a silica filter cake, and re-beaten To form a suspension solution, add polydimethylsiloxane and acrylic acid block polymer to it, then dry, pulverize and classify.

technical field

[0001] The invention belongs to the preparation technology of powder materials, in particular to a preparation method of silica matting powder for elastic paint matting. Background technique

[0002] Silica micropowder is actually an aggregate of very small silica grains, which is an amorphous white powder. Silica matting powder has the advantages of easy dispersion, good matting performance, little interference with the transparency of the coating film, little effect on the mechanical and chemical properties of the coating film, good suspension in liquid coatings, and high chemical inertness. widely used in.

[0003] The preparation of silica matting powder mainly includes three categories: precipitation method, gel method and gas phase method. Both the gas phase method and the gel method have higher production costs. And the specific surface area produced by different production processes is different. The gel method silica has the characteristics of hig...

Examples

Embodiment 1

[0021] In a 5000L stirred reactor, add 1000L water and 480L sodium silicate solution and stir evenly, raise the temperature to 45°C, and add 30% sulfuric acid dropwise to the solution at a speed of 4L / min under stirring until the pH value is 6.0-7.0, stir for 30 minutes, add 20% ammonia water to adjust the pH value to 8-9, age for 50 minutes, continue to heat up to 90°C, at this temperature, add sodium silicate with a flow rate of 0.55L / min into the reaction kettle at the same time 820L and sulfuric acid, and keep the pH value of the solution at 8-9, continue to age for 50 minutes, continue to add acid until the pH value is 4-5 after the reaction, filter and wash the reaction slurry to obtain a silica filter cake, and re-beaten To form a suspension solution, add polydimethylsiloxane and acrylic acid block polymer to it, then dry, pulverize and classify.

Embodiment 2

[0023] In a 5000L stirred reactor, add 1000L water and 500L sodium silicate solution and stir evenly, raise the temperature to 40°C, and add 30% sulfuric acid dropwise to the solution at a speed of 5L / min under stirring until the pH value is 6.0-7.0, stir for 30 minutes, add 20% ammonia water to adjust the pH value to 8-9, age for 50 minutes, continue to heat up to 85°C, at this temperature, add sodium silicate with a flow rate of 0.55L / min into the reaction kettle at the same time 750L and sulfuric acid, and keep the pH value of the solution at 8-9, continue to age for 50min, continue to add acid until the pH value is 4-5 after the reaction, filter and wash the reaction slurry to obtain a silica filter cake, and re-beaten To form a suspension solution, add polydimethylsiloxane and acrylic acid block polymer to it, then dry, pulverize and classify.

Embodiment 3

[0025] In a 5000L stirred reactor, add 1000L water and 400L sodium silicate solution and stir evenly, raise the temperature to 45°C, add 25% sulfuric acid dropwise to the solution at a speed of 4L / min under stirring until the pH value is 6.0-7.0, stir for 30 minutes, add 20% ammonia water to adjust the pH value to 8-9, age for 50 minutes, continue to heat up to 100°C, at this temperature, add sodium silicate with a flow rate of 0.55L / min into the reaction kettle at the same time 1000L and sulfuric acid, and keep the pH value of the solution at 8-9, continue to age for 50 minutes, continue to add acid until the pH value is 4-5 after the reaction, filter and wash the reaction slurry to obtain a silica filter cake, and re-beaten To form a suspension solution, add polydimethylsiloxane and acrylic acid block polymer to it, then dry, pulverize and classify.

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