JPS60137828A - Production of colloidal antimony oxide - Google Patents

Abstract

PURPOSE:To produce colloidal antimony oxide having improved stability and fine particle diameter in a high concentration, by reacting antimony trioxide with hydrogen peroxide in a specific proportion in the presence of an inorganic alkaline substance in an aqueous medium. CONSTITUTION:An inorganic alkaline substance, e.g. LiOH or NaOH, in 1.5- 30mol% concentration based on antimony trioxide is added to a dispersion (in about 5-40wt% concentration) of the antimony trioxide (preferably having about <=10mu particle diameter). Hydrogen peroxide in a molar amount of 1.25- 1.8 times of that of the antimony trioxide is added to the resultant mixture while slurrying the mixture with stirring, and the reaction is carried out at about >=30 deg.C to form a colloidal sol (in about 6-45wt% concentration) of antimony oxide. The above-mentioned colloidal sol can be concentrated without requiring the addition of a stabilizer to give easily a sol in a concentration as high as >=45wt% solid.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing colloidal antimony oxide, and more specifically, due to concerns about stability, it is difficult to produce colloidal antimony oxide industrially with a particle size of 1 to 100 microns and a high concentration. Advantageously, it relates to a method of manufacturing.

Antimony oxide has traditionally been used in conjunction with organic chlorides, bromides, and other halogen-containing substances to make textiles, fibers, plastics, etc. flame retardant. However, since all such conventional antimony fluoride particles have a particle size as large as that of a traditional Japanese fluoride, the texture, gloss, and
This causes various troubles such as deterioration of transparency, physical properties, etc.

Therefore, in recent years, one company has researched a method for obtaining fine particulate antimony oxide in order to solve this problem, and as a representative example, 5b203
with KOH and H2O2 in approximately 1:2. A technique (d
:i means are disclosed. However, since this method uses a large amount of KOH, impurities remain in the product, and d) requires a deionization step to remove the impurities. In addition, in reality, the 5b205 obtained by this method has a low concentration (the higher the concentration, the larger the particle size). On the other hand, as shown in JP-A No. 52-128997, for example, in the technique No. 1 without adding an alkali substance, there is no problem with impurity removal operation, but the reaction rate is very slow. Therefore, high temperature conditions close to boiling conditions are adopted, which poses risks such as bumping, and once the reaction starts, it rapidly generates heat due to the reaction heat, making γ quality control difficult and making it difficult to scale up. In addition, the antimony oxide obtained is used for the various purposes mentioned above, including various latexes. In many cases, the colloids are mixed with such latexes, and when mixed with such latexes, the colloids aggregate due to the inorganic salts in the latexes, resulting in a lack of chemical stability. Here, the present inventors have solved the above defects. As a result of detailed studies on the industrial production method of colloidal antimony oxide, which overcomes the problem and has commercial value, we found that the amount of hydrogen peroxide used per mole of antimony trioxide was While the stoichiometric value required for oxidation to antimony was more than 2 moles, we used much less hydrogen peroxide than this stoichiometric value and added 211 (211) moles to the reaction system. By adding the Isofune alkaline substance, all the defects associated with the prior art are eliminated, and colloidal antimony oxide with excellent stability, fine particle size, and high concentration can be produced industrially and advantageously.a
We discovered the fact that <-< and arrived at the present invention.

That is, the main object of the present invention is to provide chemically
The object of the present invention is to provide an industrially advantageous method for producing mechanically stable antimony oxide colloid mr& having a fine particle size and a high concentration. The purpose of the present invention is to provide a method for producing colloidal antimony oxide that is economically and industrially superior in terms of energy saving, simplicity of process, and ease of reaction operation.Other purposes of the present invention are as follows. The invention will become clearer from the detailed description of the invention set forth in .

The object of the present invention is to react antimony trioxide and hydrogen peroxide to form a colloidal sol of antimony oxide, with a molar ratio of antimony trioxide and hydrogen peroxide of 1:1.25 to 1.8. (-1) and is achieved by adding an inorganic alkaline substance to the reaction system.

Here, the inorganic alkaline substances used in the present invention include hydroxides of alkali metals such as lithium, potassium, and sodium, or alkaline earth metals such as magnesium, calcium, and barium; ammonia; sodium carbonate, ammonium carbonate, MA salts such as thorium phosphate
Among them, Li0H1KOH
It is preferred to use an alkali metal hydroxide such as , NaOH because it can efficiently provide a further acceleration of the reaction rate. Of course, there is no problem in using the above substances in combination.

Further, the amount of the alkaline substance used is 1.5 to 30 mol%, preferably 2 to 2 mol%, based on antimony trioxide.
It is necessary to set it within the range of 0 mol%, and if it is outside this range, the reaction promotion effect will be insufficient, so the reaction of antimony trioxide and hydrogen peroxide should be set at a temperature near the boiling point of water or above the bl1 point. Not only is it necessary to maintain the temperature, but especially in a high concentration reaction system, the particle size of the obtained antimony oxide becomes significantly coarse, which is undesirable.

In addition, if it is necessary to add a larger amount of alkaline substance to adjust the pH of the product, it is possible to add the desired amount additionally at the final stage of the reaction.0 Particle size of antimony trioxide used in the present invention may be approximately 100μ or less, but from the viewpoint of dispersibility in water, reactivity with hydrogen peroxide, etc., it is particularly 10. It is desirable that it be less than or equal to u.

Such antimony trioxide is dispersed in water to adjust the dispersion tff. The concentration of antimony trioxide in the dispersion is generally 5 to 40% by weight, particularly preferably 7 to 25% by weight. The amount of strained hydrogen peroxide used is 1.25 to 1 per mole of antimony trioxide.

It is necessary that the amount is 8 mol, preferably in the range of 1.3 to 1.8 mol. If the amount used is less than 1.25 mol, colloidal fine particles cannot be obtained, and if it exceeds 1.8 mol, the chemical stability against electrolytes such as inorganic salts will be reduced. Further, there is a problem that unreacted hydrogen peroxide remains in the obtained product, which is not preferable.

The inorganic alkali JR described in MiJ is added to the thus obtained dispersion of antimony trioxide, hydrogen peroxide, and water. There is no difference in adding hydrogen peroxide in advance, heating and reacting it, or adding hydrogen peroxide after dispersing antimony trioxide in water or an inorganic alkaline substance.

The reaction temperature in the present invention is industrially preferably maintained at 30'C or higher, preferably 50 to 100'C, but the reaction can also be initiated at a low temperature of 50'C or lower, for example. As a result, not only can the energy required to heat the reaction system be extremely reduced, but most of the heat generated by the reaction is absorbed as heat, which raises the temperature of the reaction system to the There is little need for this, and the problem of temperature control to prevent bumping has been almost eliminated.

The dispersion reacted under these conditions has a solid content of antimony oxide of about 6 to 45% by weight, depending on the concentration of antimony trioxide in the dispersion, and 8 to 9% by weight. is converted into a colloidal sol, and if necessary, by concentrating it, 4
It can also be a colloidal sol with a solid content concentration of 5% or more.

Further, it goes without saying that such a colloidal sol does not cause any colloidal destruction when left for a long time and is stable over time.

As mentioned above, when antimony trioxide is reacted with hydrogen peroxide, why does the reaction proceed easily by using less hydrogen peroxide than the stoichiometric value and by adding an inorganic alkaline substance? 1. With extremely fine particle size. It is not clear whether a chemically stable colloidal sol of antimony oxide can be obtained, but in the reaction between antimony trioxide and hydrogen peroxide, an inorganic alkaline substance fi! I (41
The antimony oxide particles produced by the specific alkali present in the reaction system are It is presumed that the antimony pentoxide is slightly different from the antimony pentoxide that was previously used.

According to the method of the present invention, the reaction between antimony trioxide and a predetermined amount of hydrogen peroxide in an aqueous medium easily proceeds by adding an appropriate amount of an inorganic alkaline substance. It is possible to produce a highly concentrated colloidal sol of antimony oxide with few impurities, extremely fine particle size, and excellent chemical stability at the following temperatures. A noteworthy effect of the present invention is that no residue remains.

In addition, in the present invention, since highly concentrated colloidal antimony oxide is obtained, evaporation DARM operation is not necessary.
Even if it is necessary, it is only a small amount, and since the reaction can be carried out at a low temperature, it has a great economical effect such as less energy consumption.Furthermore, since the reaction can be carried out at a low temperature, there is no problem such as bumping. This method has advantages such as no safety problems and easy control of the reaction temperature.

In addition, the colloidal antimony oxide according to the present invention has an extremely small particle size and a significantly increased surface area, so it is very efficient in imparting #' flame resistance and achieving the desired flame retardancy. It also has the advantage of reducing the amount of antimony required compared to existing products.

By adopting the method of the present invention, the drawbacks of conventional methods such as complexity of the process, increased product cost due to the use of expensive auxiliary materials, uneven quality, and removal of impurities from the product can be improved. All of the problems have been solved, and its quality far exceeds that of conventional colloidal sols.

However, the colloidal sol of antimony oxide obtained according to the present invention can be used as it is or, if desired, after being concentrated to a certain degree for use as a flame retardant. It is also possible to separate it and use it for the above-mentioned purposes.

The present invention will be explained in more detail by showing examples in the following.
These Examples are provided to better explain the present invention, and are not intended to limit the scope of the present invention in any way.

The light transmittance in the example is HITACHI-10.
The light transmittance of white light to a colloidal sol with a solid content of 0.4% was measured using a 18 pectrophotometer (manufactured by Hitachi, Ltd.), and the larger the value, the smaller the colloidal particles. .

Example 1 A colloidal sol of antimony oxide was synthesized using a reaction apparatus in which a three-loaf flask (volume 11) equipped with a stirrer was immersed in a 90υ constant temperature water bath.

The reaction begins by adding a predetermined amount of water, antimony trioxide, and
The mixture was slurried with N' aOH and stirred, and when the temperature of the contents reached 50'CK, an aqueous H2O2 solution (concentration 35%) was added and reacted for 1 hour.

The reaction conditions and properties of the product are shown in Table 1 below.

Reprint of the specification (no change in content) From the upper table of Table 1 and Experiments 2 to 8, it can be seen that a colloidal sol of heavy antimony having a fine particle size can be obtained.

On the other hand, in order to investigate the stability against inorganic salt electrolytes, when diluting the sample to a concentration of 0.4% at a light transmittance of 1l11, 0.5g of rhodan soda aqueous solution a (
The measurement results were as follows.

As described above, 1 experiments related to the present invention Na 2 to 5 and N[L
In No. 8, the decrease in light transmittance is small, and the fact that it is very stable in terms of stability, causing almost no aggregation even in an aqueous solution of rhodan soda (see). 5 mol%,
When the reaction was carried out according to the procedure described above, except that 10 moles of 95% were added and the reaction temperature was adjusted to 100 to 110'C, the light transmittance of the raw materials was 17% and 20%, respectively.

Procedure correction band (method) Commissioner of the Patent Office Mr. Aio Wakasugi 1.Display of the incident 1981 Patent Application No. 242906 2. Name of the invention Method for producing colloidal antimony phthalate 3. Person who makes corrections ・Relationship with 9 cases Patent applicant

Claims (1)

[Claims] (1) When antimony dioxide and hydrogen peroxide are reacted to form a colloidal sol of antimony oxide, the molar ratio of antimony trioxide and hydrogen peroxide is 1:1.25 to 1.8.
A method for producing colloidal antimony oxide, which comprises adding an inorganic alkaline substance to the reaction system. 2,,I! ! ? Claim 1: 1, 5 to 30 mol % is added to organic alkali materialized antimony.
Manufacturing method described in section. 3. The manufacturing method according to claim 1, wherein an alkali metal hydroxide is used as the inorganic alkaline substance.