CN103396694A - Preparation method for coiled-steel coating delustering agent - Google Patents

Abstract

A preparation method for a coiled-steel coating delustering agent comprises: liquor proportioning, curing, filtering and water washing, high-speed pulping, flash evaporating, high-temperature calcining, and crushing for obtaining of the product. The product has pore volume of 1.4-1.8 mL/g, a specific surface area of 250-350 m<2>/g and coating drying time of less than 60 s. The coiled-steel coating delustering agent prepared by the preparation method has no influence on dryness performance of a coiled-steel coating; and the preparation method is short in flow and easy to industrialize.

Description

The preparation method of coil steel coating matting agent

Technical field

The present invention relates to a kind of silica flatting agent, particularly a kind of coil steel coating matting agent.

Background technology

Coil steel coating originates from the U.S. of the thirties in 20th century, and the middle and later periods of the eighties, the coil streamline of the Introduced From Abroads such as the Baosteel of China, Wuhan Iron and Steel Plant, pulled open the prelude that domestic color steel is produced.The application of coil steel coating is take cold-rolled steel sheet, steel plate galvanized, Al-Zn coated steel etc. as substrate, adopt supermatic roller coat mode of production, steel plate through degreasing, chemical treatment, prime, film forming after high bake, overpainting, high bake, and reach the coating of certain physicals and resistance.And use as the sheet material of building 70% left and right in color steel.In order to reduce the defect of the outside surface that makes color steel, in coil steel coating, need to add silica flatting agent, to reduce the gloss of coating surface.But the resin curing agent that general coil steel coating uses is the sulfonic group siccative, and the silica flatting agent particle surface that uses is distributed with a large amount of surface hydroxyls, these surface hydroxyls have the ability with the sulfonic group reaction, therefore cause coil steel coating to extend time of drying.

At present the preparation method of silica flatting agent has the precipitator method and gel method, and matting agent surface prepared by these two kinds of methods is due to the adsorption of hydroxyl to acid siccative, and impact the time of drying for acid catalyzed coil steel coating more or less.Domestic also have many producers in the matting agent production process, adds the surface hydroxyl reaction of surfactant and silicon-dioxide, to reaching, reduces surface hydroxyl to the coating impact of time of drying.The preparation method of a kind of large pore volume, wide aperture silicon-dioxide is disclosed as Chinese patent CN101112991, in water glass, to add hydrophobizing agent (one or more in polyoxyethylene glycol, polyvinyl alcohol, quaternary ammonium salt water soluble surfactant active), temperature 50-90 ℃ of lower acid adding, adjust pH 10-12, aging 2-4 hour, make product.US Patent No. 3959174 uses water glass to add hydrophobizing agent (comprising inorganic ammonia salt, sodium salt and sylvite and Organic Alcohol etc.) as raw material, and at room temperature acid adding, regulate pH10-11, and is aging, continues acid adding and adjusts pH3-10, is warming up to 90 ℃ of insulations.Its effect of the hydrophobizing agent that adds is with the hydroxyl reaction of silicon-dioxide, to make its activity decreased, but due to the active substance that adds can not with the surface hydroxyl total overall reaction, the drying property that therefore causes coating more or less affected by some.

On the coil steel coating impact of time of drying, we have invented a kind of preparation method of coil steel coating matting agent, and flow process is short, are easy to realize industrialization for the surface hydroxyl of eliminating silicon-dioxide.The coil steel coating matting agent that adopts the method to prepare can not affect the drying property of coil steel coating.

Summary of the invention

The object of the present invention is to provide a kind of preparation method of coil steel coating matting agent.

The preparation method of coil steel coating matting agent of the present invention comprises the following steps:

(1) preparation sodium silicate solution and aqueous sulfuric acid;

The concentration of described sodium silicate solution is counted 3-5%wt with silicon-dioxide;

The concentration of described aqueous sulfuric acid is 10-20%wt;

(2) under 90-95 ℃, according to silicon-dioxide: sulfuric acid weight ratio=1:0.6 adds aqueous sulfuric acid in the sodium silicate solution until pH is 4-5, under temperature 90-95 ℃, keeps 2-3 hour;

(3) utilize flame filter press to wash the slip after step (2) slaking, the washing filter cake until in filter cake sodium ions content be below 0.1%wt;

(4) utilize high speed dispersor filter cake is pulled an oar under the speed of 2000 rev/mins 1-2 hour, obtain slurry;

(5) utilize expansion drying slurry to be carried out to quick dewatering drying under 100-400 ℃;

(6) adopt the fluidized bed calcination stove under 400-500 ℃, to calcine 3-5 hour dried material;

(7) material after calcining adopts the supersonic speed pulverizer to be crushed to median size 3-9 micron, makes product.

The present invention has eliminated the surface hydroxyl of silicon-dioxide to the coil steel coating impact of time of drying, and flow process is short, is easy to realize industrialization.

Embodiment

In order to make content of the present invention more be convenient to understand, below in conjunction with embodiment, technical solutions according to the invention are described further, but the present invention is not limited only to this.

Embodiment mono-

The weight percent of preparation silicon-dioxide is 3% sodium silicate solution 1000g; Under 90 ℃, add concentration 10%wt sulfuric acid 180g until slip pH is 4-5,90 ℃ of lower slaking slips of temperature 2 hours; Slip after slaking utilizes flame filter press to wash, the washing filter cake until in filter cake sodium ions content be below 0.1%wt; Utilize high speed dispersor that filter cake is pulled an oar under the speed of 2000 rev/mins and obtained slurry in 1 hour; Utilize expansion drying under 100-400 ℃, to carry out quick dewatering drying; Dried material was calcined 3 hours under 400 ℃; Material after calcining, be crushed to 3 microns of median sizes and make product.

Embodiment bis-

The weight percent of preparation silicon-dioxide is 4% sodium silicate solution 1000g; Under 90 ℃, add concentration 15%wt sulfuric acid 160g until slip pH is 4-5,90 ℃ of lower slaking slips of temperature 2 hours; Slip after slaking utilizes flame filter press to wash, the washing filter cake until in filter cake sodium ions content be below 0.1%wt; Utilize high speed dispersor that filter cake is pulled an oar under the speed of 2000 rev/mins and obtained slurry in 1 hour; Utilize expansion drying under 100-400 ℃, to carry out quick dewatering drying; Dried material was calcined 3 hours under 450 ℃; Material after calcining, be crushed to 6 microns of median sizes and make product.

Embodiment tri-

The weight percent of preparation silicon-dioxide is 5% sodium silicate solution 1000g; Under 95 ℃, add concentration 20%wt sulfuric acid 150g until slip pH is 4-5,95 ℃ of lower slaking slips of temperature 3 hours; Slip after slaking utilizes flame filter press to wash, the washing filter cake until in filter cake sodium ions content be below 0.1%wt; Utilize high speed dispersor that filter cake is pulled an oar under the speed of 2000 rev/mins and obtained slurry in 2 hours; Utilize expansion drying under 100-400 ℃, to carry out quick dewatering drying; Dried material was calcined 3 hours under 500 ℃; Material after calcining, be crushed to 9 microns of median sizes and make product.

 

Coil steel coating matting agent performance table

Interventions Requested	Desired value	Embodiment mono-	Embodiment bis-	Embodiment tri-
					Dioxide-containing silica (butt) %	≥99.0	99.3	99.2	99.3
Pore volume (ml/g)	1.4-1.8	1.65	1.70	1.61
					Specific surface area (m 2/g）	250-350	257	268	276
The pH value	6-7	6.5	6.9	6.8
					Mean particle size (μ m)	3-9	3.1	6.5	8.9
Coating time of drying (s)	<60	46	50	56

Claims (1)

1. the preparation method of coil steel coating matting agent comprises the following steps:

(1) preparation sodium silicate solution and aqueous sulfuric acid;

The concentration of described sodium silicate solution is counted 3-5%wt with silicon-dioxide;

The concentration of described aqueous sulfuric acid is 10-20%wt;

(2) under 90-95 ℃, according to silicon-dioxide: sulfuric acid weight ratio=1:0.6 adds aqueous sulfuric acid in the sodium silicate solution until pH is 4-5, under temperature 90-95 ℃, keeps 2-3 hour;

(3) utilize flame filter press to wash the slip after step (2) slaking, the washing filter cake until in filter cake sodium ions content be below 0.1%wt;

(4) utilize high speed dispersor filter cake is pulled an oar under the speed of 2000 rev/mins 1-2 hour, obtain slurry;

(5) utilize expansion drying slurry to be carried out to quick dewatering drying under 100-400 ℃;

(6) adopt the fluidized bed calcination stove under 400-500 ℃, to calcine 3-5 hour dried material;

(7) material after calcining adopts the supersonic speed pulverizer to be crushed to median size 3-9 micron, makes product.