JPH0764565B2 - Organo antimony pentoxide sol and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a novel organoantimony pentaoxide sol using an acid amide solvent such as dimethylformamide, dimethylacetamide, formamide, acetamide or the like, or dimethylsulfoxide and the like, and its production. Concerning the law.

The antimony pentoxide sol is a colloidal antimony pentoxide sol with a particle size of 5 to 100 mμ and shows a flame retardant effect when used in combination with a halogen compound. Therefore, it is a flame retardant for plastics, fibers, etc. It is used as an agent (inorganic ion exchanger). In particular, it has attracted attention as a transparent flame retardant because of its small particle size.

Antimony pentoxide sols using the above organic solvents such as dimethylformamide (hereinafter referred to as DMF) as a dispersion medium are mainly studied for flame retardancy of acrylic fibers.

(Prior Art) The following method has been proposed as a conventional method for producing an organoantimony pentaoxide sol.

A method in which anhydrous antimony trioxide is added to nitric acid, α-hydroxycarboxylic acid is added after heating, and then an organic solvent such as DMF is added, and water is removed by distillation (JP-A-47-1138).
2).

A method in which a hydrophilic organic solvent such as DMF and α-hydroxycarboxylic acid are added to hydrogen halide such as hydrogen chloride, and then antimony trioxide is dispersed and oxidized with hydrogen peroxide solution (JP-A-52-38495). , JP-A-52-38496).

A dry powder of amine-stabilized antimony pentoxide sol obtained by the method of oxidizing antimony trioxide with aqueous hydrogen peroxide was used.
A method of dispersing in an organic solvent such as DMF (JP-A-52-12399)
7) etc.

Further, it is described in the above patent that the obtained antimony pentoxide sol can be mixed into acrylic fiber and the fiber can be made flame-retardant without losing the transparency of the fiber.

However, the former two types contain many acids (inorganic acids and carboxylic acids), so they not only have the possibility of degrading organic solvents such as DMF themselves, but also decrease the physical properties of the polymer, It has the drawbacks of corroding and making it difficult to recover the organic solvent. Further, the latter amine-stabilized organomonium pentaoxide sol has a drawback that the sol lacks stability of the sol itself and its dispersibility in a polymer is poor, so that the transparency and flame retardancy are not sufficiently effective. ing.

Flame-retardant acrylic fibers (halogenated modacrylic fibers) are, for example, two-component polymers obtained by copolymerization of acrylonitrile with vinyl chloride and vinylidene chloride by combining acrylonitrile with a suitable sulfonic acid derivative, preferably an alkylamidoalkanesulfonic acid derivative. It is prepared by mixing the polymer obtained by copolymerization in an appropriate ratio.

A method for producing a heat-resistant modacrylic fiber by dissolving the above polymer in an organic solvent such as DMF to obtain a spinning solution, and mixing and spinning a suspension of an antimony pentoxide aqueous colloid, water and an organic solvent such as DMF, and spinning the mixture. Proposed (JP Sho
55-142715). Commercially available amine-stable antimony pentoxide aqueous sol has poor compatibility with DMF, and does not enter into a sol state unless a large amount of water is contained. Therefore, in the above patent, the water content in the suspension is 20 to 40% by weight, and in the examples, Sb ₂ O ₅ 6.75%, H ₂ O 30%, and DMF 63.25%. In this way, when the amount of antimony pentoxide added is increased due to containing a large amount of water, the amount of water in the spinning solution is increased, partial spinning of the spinning solution occurs, and the antimony pentoxide sol may be uniformly dispersed. It becomes difficult, and the spinnability is deteriorated due to thickening of the spinning solution, and further the transparency of the fiber is lowered. Therefore, in order to uniformly disperse a large amount of antimony pentoxide sol in the spinning solution and efficiently obtain highly transparent fibers, it is necessary to use an organoantimony pentoxide sol with DMF having a low water content as a solvent. Become.

(Problems to be Solved by the Invention) The present inventors have conducted intensive studies for the purpose of improving the above-mentioned drawbacks of the conventional antimony pentoxide sol, and as a result, have already obtained 3 It has been found that a cationic sol can be obtained by adding a basic salt of a monovalent or tetravalent metal (Japanese Patent Application Laid-Open No. 60-70720), but by replacing the water of the cation sol with an organic solvent such as DMF. It was found that the desired organoantimony pentoxide sol can be obtained.

That is, the object of the present invention is to produce a flame-retardant acrylic fiber with an organic solvent such as DMF or dimethylacetamide, which can be mixed uniformly and stably and has a good flame-retardant effect without impairing the transparency of the fiber. It is to provide a method for producing a stable antimony pentaoxide sol using a dispersion medium such as DMF or dimethylacetamide as a dispersion medium.

(Means for Solving Problems) That is, according to the present invention, the surface of colloidal particles of an antimony pentaoxide sol having an acid amide solvent or dimethylsulfoxide as a dispersion medium is covered with a trivalent and / or tetravalent metal, The present invention relates to an organoantimony pentaoxide sol characterized in that the amount of the metal is 1 to 50% by weight with respect to antimony pentoxide (Sb ₂ O ₅ ) as a metal oxide.

The fact that the surface of the antimony pentoxide colloidal particles of the present invention is covered with the above metal means that the surface of the antimony pentoxide colloidal particles is a state in which the metal is in the form of a polycation or a fine colloid of the metal oxide or hydroxide. It is fixed to. The Sb ₂ O ₅ concentration of the antimony pentoxide sol is 1 to 50% by weight, and the colloid covered with the metal has an average particle size of 5 to 150 mμ.

The method for producing the organoantimony pentoxide sol of the present invention comprises 5 to 60% by weight of antimony pentoxide (Sb ₂ O ₅ ).
An aqueous solution of a basic salt of a trivalent and / or tetravalent metal is added to an aqueous antimony pentaoxide sol having H of 1 to 10 as an amount of the basic salt as a metal oxide with respect to antimony pentaoxide (Sb ₂ O ₅ ). 1
After adding 50% by weight to positively charge the surface of the antimony pentoxide colloid, add acid amide solvent,
Alternatively, it is characterized by being obtained by adding dimethyl sulfoxide and substituting the solvent under normal pressure or reduced pressure.

As the antimony pentoxide aqueous sol used in the present invention,
Method for decationizing an alkali salt of antimonic acid with an ion exchange resin (Japanese Patent Publication No. 57-11848, U.S. Pat. No. 411)
No. 0247), a method of oxidizing antimony trioxide with hydrogen peroxide at high temperature (Japanese Patent Publication No. 53-20479 and Japanese Patent Publication No. 52-212).
98) or a method of deflocculating an antimony pentoxide gel obtained by reacting an alkali antimonate with an inorganic acid filed by the present inventors (JP-A-60-41536, Japanese Patent Application No. 60-7).
No. 0719), an antimony pentoxide aqueous sol obtained by any method can be used. Further, amine and / or alkali hydroxide was added to the amine-free acidic sol of pH 1 to 4 obtained by the ion exchange method, hydrogen peroxide method, and peptization method.
A sol having a pH of 4 to 10 can also be used.

Antimony pentoxide aqueous sol is antimony pentoxide (Sb
Although ₂ O ₅₎ concentration can be used those of 5-60 wt%, solvent substitution, those from the viewpoint of the concentration efficiency of Sb ₂ O ₅ 10 to 50 wt% preferred. Also, antimony pentoxide sol has a particle size of 5 to 100 m.
μ can be used.

The water-soluble basic salt used in the present invention is trivalent and / or tetravalent.
A basic salt of a valent metal and aluminum, chromium, iron, indium, or yttrium is used as the trivalent metal. Zirconium, tin, titanium and cerium are used as the tetravalent metal. Preferred among these metals are aluminum, zirconium, tin and titanium. As the acid, hydrochloric acid, nitric acid, sulfuric acid, sulfamic acid, acetic acid, formic acid, oxalic acid and the like are used, but hydrochloric acid and acetic acid are preferably used.

In the present invention, a basic salt having any composition can be used, but a salt having a small acid amount is preferable. For example, basic aluminum chloride (Al ₂ (OH) ₅ Cl, Al (OH) ₂ Cl), basic aluminum acetate (Al ₂ (OH) ₅ CH ₃ C00 ・ 1 / 3H ₃ BO ₃ ), basic zirconium nitrate (ZrO (NO ₃ ) ₂ ), base zirconium acetate (ZrO (C
H ₃ C00) ₂ ), basic zirconium chloride (ZrOCl ₂ ), basic titanium chloride (Ti (OH) Cl ₃ ), basic tin chloride (Sn (OH) C
l ₃ ) and the like.

These basic salts are available as powders or aqueous solutions, some of which are commercially produced.

The surface of the antimony pentoxide colloid is negatively charged,
Also, since it has a strong cation exchange ability, when the above-mentioned basic aqueous solution is added to the antimony pentoxide aqueous sol, the polycations in the basic salt are not strongly adsorbed on the surface of the antimony pentoxide colloid, but rather by chemical bonding. It is possible to obtain a very stable sol that is fixed and does not require heat treatment.

Since agglomerated gel often occurs temporarily during the mixing, it is preferable to perform strong stirring with a disper, a homogenizer or the like. In addition, when a method of adding an antimony pentoxide aqueous gel to an aqueous solution of a basic salt is adopted, the gel is less likely to be formed and the stirring time for obtaining a uniform sol can be shortened.

In the present invention, the basic salt is added in an amount of 1 to 50% by weight, based on antimony pentoxide (Sb ₂ O ₅ ), as the metal oxide (M ₂ O ₃ or MO ₂ ) constituting the basic salt, preferably Is 3 to 20
% By weight. The amount of the basic salt added varies depending on the surface area of the antimony pentoxide colloid, but if it is less than 1% by weight, it cannot be sufficiently positively charged, and the mixed solution gels.
Even if 50% by weight or more is added, the effect is the same and the amount of coexisting anions increases, which is inconvenient for use.

A positively charged sol having a pH of 0 to 7 can be obtained by adding a basic salt to an antimony pentoxide aqueous sol having a pH of 1 to 10, but when the pH is low, alkali metal hydroxide, ammonia, amine, Basic substances such as quaternary ammonium hydroxide and guanidine hydroxide,
If necessary, the pH can be adjusted by adding acids such as hydrochloric acid, nitric acid, formic acid, oxalic acid, tartaric acid. The pH is preferably 2-6.

The concentration of antimony pentoxide (Sb ₂ O ₅ ) can be easily adjusted to 30 to 50% by weight by concentrating the positively charged antimony pentoxide aqueous sol by an evaporation method or an ultrafiltration method.

Solvent substitution under normal pressure or reduced pressure while adding an organic solvent selected from DMF, dimethylacetamide, formamide, methylformamide, acetamide, dimethylsulfoxide, etc. to the positively charged antimony pentoxide aqueous sol obtained by the above method. As a result, an organoantimony pentaoxide sol having an antimony pentoxide (Sb ₂ O ₅ ) concentration of 20 to 50% by weight can be obtained.

The antimony pentoxide aqueous sol can be concentrated before solvent replacement, during replacement, or after replacement, if necessary.
Since the amount of substitution is small, it is preferable to carry out before substitution.

The organoantimony pentaoxide sol of the present invention does not impair the stability of the sol due to the presence of water, and the water content can be freely controlled, but the water content is 0% in the sol.
-20% by weight is preferred.

The organoantimony pentoxide sol of the present invention can be stably added to the spinning solution of flame-retardant acrylic fiber (modacrylic fiber), and does not cause pressurization during spinning or nozzle clogging,
The spinnability was good, the resulting fiber was highly transparent and showed good flame retardancy.

Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples. However, the present invention is not limited to the examples below. All% in the following examples are% by weight unless otherwise specified.

Example 1 Acidic antimony pentoxide sol (Sb obtained by ion exchange method)
₂ O ₅ 12%, Na ₂ O 0.70%, Na ₂ O / Sb ₂ O ₅ molar ratio 0.3, pH 2.7,
Basic aluminum chloride aqueous solution (Al
₂ (OH) ₅ : Takibaine Taki Kagaku Co., Ltd.) (75 g) was added with stirring with a disper and the mixture was stirred for about 1 hour. The obtained cationic sol was Sb ₂ O ₅ 11.6%, Al ₂ O ₃ 0.83%, Al ₂ O ₃ / Sb ₂ O ₅ ratio 7.
It was 19% and pH 3.0. This sol was concentrated to 60% Sb ₂ O ₅ at 60 ° C. by a rotary evaporator to obtain 800 g of sol. Next, 600 g of DMF was added to this, and solvent replacement was performed. The obtained DMF antimony pentoxide sol has a specific gravity of 1.43.
5. The viscosity was 20.cp, Sb ₂ O ₅ 30%, Al ₂ O ₃ 2.16%, and H ₂ O 2.1%. This sol was stable at 40 ° C for over 1 month.

Example 2 (Production Method of Amine-Free Antimony Pentoxide Aqueous Sol as Starting Material) The method described in Japanese Patent Application No. 60-70719 was used. That is, 800 g of sodium antimonate was dispersed in 830 g of pure water, 420 g of 35% hydrochloric acid was added to this while stirring, and the mixture was heated to 30 ° C. and
Reacted for hours. Then, the produced antimony pentoxide gel slurry was suction-filtered, and 1800 g of pure water was poured to wash.

830 g of the obtained antimony pentoxide wet cake was added to pure water 24
Disperse into 90 g, and stir in this with 85% orthophosphoric acid 8.5
g was added and the mixture was heated to 80 ° C. and deflocculated for 2 hours to obtain a deflocculated sol.

The obtained antimony pentoxide aqueous sol was Sb ₂ O ₅ 15.0%, Na ₂
O was 1.0%, pH was 2.5, and the particle size was 20 mμ.

(Manufacturing method of organoantimony pentaoxide sol) 1050 g of antimony pentaoxide aqueous sol obtained by the above method
To this, 12.0 g of 93% caustic soda was added, and the mixture was vigorously stirred for 1 hour, after which the same basic aluminum chloride aqueous solution as in Example 1 was added.
g was added and stirred for about 1.5 hours. The obtained cation sol was Sb ₂ O ₅ 14.0%, Al ₂ O ₃ 1.33%, Al ₂ O ₃ / Sb ₂ O ₅ ratio 9.50%,
It was pH 5.0. This sol was concentrated to 40% Sb ₂ O ₅ at 40 ° C. by a rotary evaporator, and solvent substitution and concentration were performed simultaneously while adding 450 g of dimethylacetamide to obtain a sol. The obtained dimethylacetamide antimony pentoxide sol had a specific gravity of 1.472, a viscosity of 25.cp, Sb ₂ O ₅ 32.0% and Al ₂ O ₃
3.04%, was H ₂ O4.6%. This sol was stable even when left at 40 ° C. for 1 month.

Example 3 A high-concentration antimony pentoxide sol (Sb ₂ O ₅ 41.0%, Na ₂ O 3) obtained by adding an aqueous potassium hydroxide solution to the antimony pentoxide sol used in Example 1 and concentrating by an ultrafiltration method. .0%,
K ₂ O3.2%, pH6.5) 800g basic zirconium acetate solution _{(Zr (CH 3 COO) 2} : Shin Nippon Metal Chemical Corporation, trade name zirconyl acetate _{S-20, ZrO 2 20.3%} , CH 3 COOH14. 7%, pH 3.
1) A mixture of 215 g and water 78 g was added with stirring with a dipper, and the mixture was stirred for 2 hours. The obtained sol is Sb ₂ O ₅ 30.0
%, ZrO ₂ 4.0%, ZrO ₂ / Sb ₂ O ₅ molar ratio 13.3%, CH ₃ COOH2.8
The viscosity was 9%, the viscosity was 15.9 cp, and the pH was 4.6. While adding 600 g of DMF to this, solvent substitution was carried out at 70 ° C. by a rotary evaporator. The obtained DMF antimony pentoxide sol had a specific gravity of 1.481, a viscosity of 6.0 cp, Sb ₂ O ₅ 30.0%, ZrO ₂ 4.0% and H ₂ O.
It was 5.2%. This sol was stable even when left at 50 ° C for 1 month or longer.

Example 4 High-concentration antimony pentoxide sol (Sb ₂ O ₅ 50.5%, Na ₂ O 3.8%, triethanolamine) produced by the peptization method and concentrated
2.4%, pH 6.2, particle size 25 mμ) 520 g of basic zirconium chloride aqueous solution (manufactured by Daiichi Rare Elements Industry Co., Ltd., trade name Zirconyl Oxychloride ZC-20; ZrO ₂ 20.8%, Cl8.7%) 250 g and water 300 g The mixture was added to the mixed solution with a dipper while stirring strongly and stirred for 1 hour. The obtained sol was Sb ₂ O ₅ 24.5%, ZrO ₂ 4.86.
%, ZrO ₂ / Sb ₂ O ₅ molar ratio 19.8%, pH <1. Solvent substitution was carried out at 50 ° C. on a rotary evaporator while adding 750 g of DMF to this sol. The obtained DMF antimony pentoxide sol had a specific gravity of 1.370, a viscosity of 7.0 cp, and Sb ₂ O ₅ 24.5.
%, ZrO ₂ 4.9%, and H ₂ O 3.5%. This sol was stable even at 40 ° C. for 1 month or longer.

Comparative Example 1 Example acidic diantimony pentoxide aqueous sol used in _{1 (Sb 2 O 5 12%} ) Sb 2 O 5 to 500g on a rotary evaporator
When it was concentrated to 22.0% and solvent substitution was performed while adding 220 g of DMF to it, the viscosity increased remarkably as the amount of water in the sol decreased, and it was not possible to obtain a DMF antimony pentoxide sol with a low water content. . Even when the Sb ₂ O ₅ concentration was reduced to 10%, the viscosity of the sol was 50 c.p. or more, and the stability was poor.

Comparative Example 2 Acidic antimony pentoxide sol (Sb ₂ O used in Example 2)
₅ 12%) 800 g was added an aqueous basic aluminum chloride solution 4.5g used in Example 1, was stirred with a disper.
The sol caused micro-aggregation and became a highly viscous slurry. Solvent substitution was performed with a rotary evaporator while adding 640 g of DMF to this slurry, but aggregates were not reduced and a sol could not be obtained.

Claims (2)

[Claims] 1. A polycation of a metal having a trivalent and / or tetravalent metal or an oxide or water of the metal having an acid amide solvent or an antimony pentaoxide sol containing dimethylsulfoxide as a dispersion medium and having colloidal particles on the surface thereof. The oxide is coated in the form of micro colloid, and the amount of the metal is 1 to 50 with respect to antimony pentoxide (Sb ₂ O ₅ ) as a metal oxide.
An organoantimony pentoxide sol characterized by being in a weight percentage. 2. Antimony pentoxide (Sb ₂ O ₅ ) 5 to 60
An aqueous solution of a trivalent and / or tetravalent metal basic salt is added to an aqueous antimony pentoxide sol having a pH of 1 to 10 containing 10% by weight,
The basic salt is added as a metal oxide in an amount of 1 to 50% by weight with respect to antimony pentoxide (Sb ₂ O ₅ ),
A method for producing an organoantimony pentaoxide sol, which comprises positively charging the surface of an antimony pentoxide colloid, adding an acid amide solvent or dimethyl sulfoxide to the surface, and then substituting the solvent under normal pressure or reduced pressure.