KR100483482B1 - Method for manufacturing the nano powder of autimony oxides - Google Patents

Abstract

The present invention relates to a method for producing antimony pentoxide, which is added as a flame retardant to a material such as synthetic resin, and distilled water is added at a reaction rate of 2.5 to 3 moles with respect to 1 mole of antimony trioxide in a reactor and then mixed at a constant rotational speed using a stirrer. Dissolution step of producing a suspension of antimony trioxide; An exothermic step of adding a hydrogen peroxide solution at a reaction ratio of 2-3 mol to 1 mol of antimony trioxide to the suspension produced in the dissolution step and reacting at a temperature of 40-70 ° C. for 1-2 hours to produce a suspension of antimony pentoxide; A aging step of cooling the suspension of the antimony pentoxide generated in the exothermic process for at least 1.5 to 2 hours through natural reflux while maintaining the 2-3 atm state in the reactor; The antimony pentoxide powder is produced by injecting the aging product of the antimony pentoxide produced in the aging process into a dryer and then spraying it at a pressure of 0.5 to 0.7 kg / ㎠ while adjusting the viscosity by adding a stabilizer to powder the antimony pentoxide. Very fine and low specific gravity can improve the quality of products such as circuit boards, as well as improve the flame retardancy of products such as synthetic resins.

Description

Method for manufacturing nano powder of antimony pentoxide {Method for manufacturing the nano powder of autimony oxides}

The present invention relates to a method for producing antimony pentoxide, which is added as a flame retardant to materials such as synthetic resins. Particularly, after adding distilled water and hydrogen peroxide to antimony trioxide, the reaction time and reaction temperature can be adjusted to prepare fine antimony pentoxide. The present invention relates to a method for preparing nanopowders of antimony pentoxide.

In general, as modern civilization develops, as the quality of electronic devices and various materials is functionalized, the use of flame retardants is increasing rapidly. In particular, in the case of new materials based on synthetic resins or PVC resins, flame retardancy is urgently required in order to prevent fire and protect people.

Conventionally, antimony trioxide is mainly used as a flame retardant such as a synthetic resin, and other alumina sol and silica sol have been used, but researches on antimony pentoxide as a means to supplement their flame retardant effect and dispersibility are underway.

In particular, antimony pentoxide is known to improve properties such as transparency, coloration, flame retardancy, etc. of synthetic resins and PVC resins only when the specific gravity is low and the powder is very fine and excellent in dispersibility.

On the other hand, as a method for producing antimony pentoxide, an ion substitution method or an inorganic acid method has been developed. Among these, an ion exchange method requires an ion exchange process, which is complicated. There was a problem that the manufacturing cost is increased by the addition of the process of filtration washing.

In addition, Japanese Patent Laid-Open No. 52-1298 proposes a method for producing antimony pentoxide by heating particles of antimony trioxide to a temperature of 90 to 105 ° C. and then reacting with hydrogen peroxide solution. As antimony is precipitated by its own weight, the dispersion efficiency is lowered, which makes it difficult to form fine particles.

Thus, the present invention was devised to solve the problems as described above, to add the distilled water and hydrogen peroxide water to the antimony trioxide, and then to control the reaction time and reaction temperature to produce a powder of antimony pentoxide in ultrafine state It is an object of the present invention to provide a method for preparing nanopowders of antimony pentoxide.

The present invention for achieving the above object is to dissolve distilled water in a reaction ratio of 2.5 to 3 moles with respect to 1 mole of antimony trioxide in the reactor and then mixed at a constant rotational speed using a stirrer to produce a suspension of antimony trioxide fair; An exothermic step of adding a hydrogen peroxide solution at a reaction ratio of 2-3 mol to 1 mol of antimony trioxide to the suspension produced in the dissolution step and reacting at a temperature of 40-70 ° C. for 1-2 hours to produce a suspension of antimony pentoxide; A aging step of cooling the suspension of the antimony pentoxide generated in the exothermic process for at least 1.5 to 2 hours through natural reflux while maintaining the 2-3 atm state in the reactor; After the aging of the antimony pentoxide produced in the aging process is added to the dryer, and stabilized by adding a stabilizer and spraying at a pressure of 0.5 ~ 0.7 ㎏ / ㎠ to powder the antimony pentoxide is characterized in that the powder manufacturing process consisting of.

Hereinafter, an embodiment according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a process chart showing a process for producing nanoparticles of antimony pentoxide in accordance with the present invention, distilled water is added in a reactor with a reaction ratio of 2.5 to 3 moles with respect to 1 mole of antimony trioxide in a reactor and then mixed at a constant rotation speed using an agitator A dissolution step of producing a suspension of antimony trioxide; An exothermic step of adding a hydrogen peroxide solution at a reaction ratio of 2-3 mol to 1 mol of antimony trioxide to the suspension produced in the dissolution step and reacting at a temperature of 40-70 ° C. for 1-2 hours to produce a suspension of antimony pentoxide; A aging step of cooling the suspension of the antimony pentoxide generated in the exothermic process for at least 1.5 to 2 hours through natural reflux while maintaining the 2-3 atm state in the reactor; After the aging of the antimony pentoxide produced in the aging process is added to the dryer, and stabilized by adding a stabilizer and spraying at a pressure of 0.5 ~ 0.7 ㎏ / ㎠ to powder the antimony pentoxide is characterized in that the powder manufacturing process consisting of.

Here, the antimony trioxide, which is the main raw material used in the present invention, maintained a high purity of 99.65% or more, and used a particle size of 0.4 to 0.5 μm, and hydrogen peroxide introduced into the oxidant used a purity of about 35% or more. The internal temperature was kept within ± 3 ° C of the specified value.

In addition, the production apparatus of the antimony pentoxide, that is, the reactor is formed of pyrex glass (funre), the funnel (oxidizer) is injected into the body (funnel), a cooler for evaporation of an aqueous solution, a stirrer equipped with an impeller, temperature measurement There is a dummy (thermister), a heating device for controlling the reaction temperature and the like.

EXAMPLE

First, with funnel, cooler, stirrer, dummyster, heating device, etc. installed in a reactor (not shown), 5 kg of antimony trioxide and 12.5 L of distilled water are added at a ratio as shown in Table 1, and a fixed rotation is performed using a stirrer. Suspension (slurry) of antimony trioxide was prepared while mixing at a speed.

At this time, the rotational speed of the stirrer is preferably 50 ~ 100RPM, this rotational speed can be increased or decreased.

In addition, the reason for adding antimony trioxide and distilled water in a reaction ratio of 1: 2.5 to 3 is that when the distilled water is added below the prescribed value, the heating temperature is increased due to the formation of the final product, and the yield is lowered. This is because the time due to the production of the suspension is delayed and the working time is increased.

TABLE 1

Furtherance Oxidizer Antimony trioxide Distilled water Hydrogen peroxide amount 5 kg 12.5ℓ 5ℓ Wt% 28.6 71.4 Antimony trioxide: 3 mol

after that. The heating device installed in the reactor was operated to set the internal temperature to a temperature range of 40 to 70 ° C., followed by stepwise addition of hydrogen peroxide, an oxidizing agent, into the reactor in a range of 5 L and maintained for 1.5 to 2 hours. An intermediate of state was formed.

At this time, the reason why the addition of antimony trioxide and hydrogen peroxide at a reaction ratio of 1: 2 to 3 is that when the hydrogen peroxide solution is added above the prescribed value, the intermediate material turns milky and the suspension properties are deteriorated, while the hydrogen peroxide solution is below the prescribed value. This is because when added, the suspension is boiled and the yield is lowered.

In addition, the reason why the internal temperature of the reactor was maintained in the temperature range of 40 to 70 ° C. is that almost no antimony pentoxide is produced at the temperature below 40 ° C., while the suspension boils at a temperature above 70 ° C., thereby increasing the pressure in the reaction system. This is because a large amount of time is required in the maturation process.

The reason why the reaction time of antimony trioxide and hydrogen peroxide solution was maintained for 1.5 to 2 hours was because the particle size of the suspension became very fine as a result of maintaining the reaction time at 1.5 to 2 hours. It is interpreted to affect the reduction of lysate (water).

Therefore, in the reaction process of antimony trioxide and hydrogen peroxide, it can be seen that the internal temperature of the reactor and the reaction time are important in terms of miniaturization of antimony pentoxide.

Subsequently, after 30-40 minutes of addition of hydrogen peroxide solution to the antimony trioxide, the temperature rose to about 90 ° C. due to the exothermic reaction, and the suspension of antimony trioxide turned pale yellow to a suspension of antimony pentoxide. Was produced, the composition of which is shown in Table 2.

At this time, the reason why antimony pentoxide is generated in the reaction process of antimony trioxide and hydrogen peroxide is because the antimony trioxide and hydrogen peroxide react to form antimony pentoxide and water by a binding formula as shown in Equation (1).

(Formula 1): Sb ₂ O ₃ + 2H ₂ O ₂ ― → Sb ₂ O ₅ + 2H ₂ O

Then, the suspension of the antimony pentoxide was cooled for at least 1.5 to 2 hours through natural reflux while maintaining a 2-3 atm state in the reactor to mature antimony pentoxide, resulting in a sol-type antimony pentoxide.

TABLE 2

Moisture content (%) PH Antimony pentoxide (%) Density (g / cm 3) Particle size (㎛) 61.6 4.31 38.4 3.70 0.19

On the other hand, in the case of controlling the particle size of the final product in the course of the reaction of the suspension of antimony trioxide and hydrogen peroxide, it can be controlled by the step of the dosage of hydrogen peroxide, which is exothermic reaction of antimony trioxide and hydrogen peroxide continuously This is because the reaction temperature can be controlled.

In addition, the particle size of the final product can be controlled by adjusting the reaction time of antimony trioxide and hydrogen peroxide solution, which may be interpreted as the breakdown of particles during the transition from antimony trioxide to antimony pentoxide.

Meanwhile, antimony pentoxide matured in the reactor was introduced into a dryer (Two fluid nozzle type, inlet temperature: 250 to 270 ° C, outlet temperature: 110 to 120 ° C), and sprayed at a pressure of 0.5 to 0.7 kg / cm 2. It is possible to obtain nanoparticles of high purity antimony pentoxide without using the same grinding device.

At this time, in order to control the particle size of the antimony pentoxide introduced into the dryer, it is preferable to add an organic salt containing amines or an inorganic salt containing sodium hydroxide as a stabilizer.

Of course, the stabilizer added to the antimony pentoxide is known to play a role of reducing the reaction time while reducing the particle size of the final product while acting as a catalyst to shorten the reaction time.

In addition, amines include ethyl amine, alkyl amine such as butyl amine and triethyl amine, monoethanol amine and diethanol amine. Alkanol amines such as -ethanol amine and Tri-ethanol amine, and alkanol amine salts such as triethylamine and phosphoric acid.

TABLE 3

Contents Antimony pentoxide (%) P H Deposition weight (B / D) Particle size (㎛) color L a b result 79.16 4.65 1.175-1.275 4.56 99.23 -0.18 +0.39 98.85 -0.23 +0.85

Meanwhile, as shown in Table 3, the powder of the antimony pentoxide powder from which the moisture contained in the aging solution of the antimony pentoxide is removed by the dryer has a low acidity (PH: 4.65) and low deposition specific gravity (1.175 to 1.275). Of course, since the particle size (4.56) is fine, all the conditions for improving the flame retardancy is satisfied.

As described above, according to the method for preparing nanoparticles of antimony pentoxide according to the present invention, since distilled water and hydrogen peroxide solution are added to antimony trioxide, the reaction time and reaction temperature are adjusted to produce antimony pentoxide, according to the preparation of antimony pentoxide powder. Not only does the work man-hours be simplified, but the additional costs are reduced, and the particle size of the antimony pentoxide is low and the deposition weight is low, which not only improves the quality of products such as circuit boards, but also improves the flame retardancy of synthetic resin products. have.

1 is a process chart showing a nano powder manufacturing process of antimony pentoxide in accordance with the present invention.

Claims (3)

A dissolution step of adding distilled water to the antimony trioxide introduced into the reactor to produce an antimony trioxide suspension; An exothermic step of adding hydrogen peroxide solution to the antimony trioxide suspension to produce an antimony pentoxide suspension; In the manufacturing method of antimony pentoxide which consists of a maturation process which cools this antimony pentoxide suspension through natural reflux and matures antimony pentoxide, In the dissolving step, distilled water is added and stirred at a reaction ratio of 2.5 to 3 moles to 1 mole of antimony trioxide, and hydrogen peroxide solution is added to a molar ratio of 2-3 moles to 1 mole of antimony trioxide suspension in the exothermic step, and then at 40 to 70 ° C. Allowed to react for 1-2 hours, The method further includes a powder manufacturing step of adding the antimony pentoxide produced in the aging process to a dryer, adding a stabilizer to adjust the viscosity, and spraying at a pressure of 0.5 to 07 kg / cm 2 to refine the antimony pentoxide. The dryer is maintained at the inlet temperature of 250 ~ 270 ℃ and the outlet temperature of 110 ~ 120 ℃, the stabilizer is an organic salt containing amines or inorganic salts containing sodium hydroxide antimony pentoxide, characterized in that Nano powder manufacturing method. delete delete