JPH01246291A - Method for removing organotin compound - Google Patents

Abstract

PURPOSE:To readily and efficiently remove an organotin compound useful as an organic synthesis catalyst, etc., from an organotin-containing solution, by converting the organotin compound in an oil-soluble substance into a compound insoluble or sparingly soluble in oils by a specific method and extracting the resultant compound with water. CONSTITUTION:An oil-soluble substance containing an organotin compound, such as organotin chloride, is initially treated with a sulfonic acid compound, sulfamic acid compound or a salt thereof (preferably sulfate, sulfamate or Na salt thereof) to convert the organotin compound in the oil-soluble substance into an organotin compound insoluble or sparingly soluble in oils. The resultant compound is then extracted with water and removed from the oil-soluble substance. Furthermore, the molar amount of the sulfonic acid compound, sulfamic acid compound or salt thereof used may be normally 1-10 times based on the organotin compound.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an industrially useful method for removing organotin compounds.

[Prior art and problems to be solved by the invention] Mono- and di-organotin compounds have high industrial value, and are used as stabilizers for polyvinyl chloride resins, organic synthesis catalysts, - cationic electrodeposition coating catalysts, etc. Tri-organotin compounds are often used as synthetic intermediates, etc., and triorganotin compounds also occupy an important position in fields such as agricultural chemicals. In particular, in recent years, organotin oxide has been used in organic synthesis reactions such as transesterification.
It is heavily used as a catalyst. Various organotin halides, organotin carboxylates, and organotin mercaptides are also used.

Among these compounds, organotin halides are generally produced by a disproportionation reaction between tetraorganotin and tin halide, but at that time, a black or brown substance that is extremely difficult to remove is produced as a by-product. One way to remove this by-product is to obtain the main product, organotin halide, by distillation and leave it as a residual fragrance, but not only does this require equipment, but organotin halide is unstable to heat. Therefore, various side reactions occur during the distillation process, leading to a decrease in yield and quality, making it extremely uneconomical and not suitable for industrial use. In addition, organotin oxide is usually produced by hydrolyzing organotin halide in the presence of an alkaline substance, but in this case as well, organotin oxide other than the intended purpose is produced as a by-product, and conventionally there have been problems in its removal. Ta.

In addition, organotin oxides, organotin mercaptides, organotin alkoxides, and even organotin halides are used as catalysts in organic synthesis reactions, but these compounds are usually insoluble or poorly soluble in water and therefore difficult to remove from the reactants. Have difficulty. For this reason, measures have been taken to separate the target product by distillation and leave the organic tin compound as a catalyst as a residual aroma, or to separate it into the mother liquor by means such as recrystallization.

However, all of these methods have equipment problems such as the need for special equipment, and they have not been able to obtain industrially satisfactory results in terms of the removal rate of organotin compounds and the yield of the target product. The reality is that it is not.

In general, reactions using organotin compounds as catalysts yield the desired product in good yield and quality, so if this catalyst can be removed without using special purification methods, the desired product can be used as a product as is. It is possible. Therefore, an object of the present invention is to provide a method for simply and efficiently removing an organotin compound from an organotin compound-containing liquid.

[Means to solve the problem]

In order to achieve the above object, the present inventors have made extensive studies and found that it is possible to convert the organic tin compound contained in the oil-soluble substance into an oil-insoluble or sparingly soluble organic tin compound, and then extract it with water, which is extremely economical. They have discovered that organic tin compounds can be effectively removed, and have completed the present invention.

The present invention relates to a method for removing an organotin compound, which is characterized by converting the organotin compound contained in an oil-soluble substance into an oil-insoluble or poorly soluble organotin compound, and then extracting the compound with water.

Examples of organotin compounds to which the method of the present invention can be applied include organotin halides (organotin chloride, organotin bromide, organotin iodide, etc.), organotin oxide, organotin acid,
Organotin hydroxide, organotin sulfite, organotin mercaptan, organotin sulfate, organotin alkoxide (the alkoxide part contains an alkyl group having 1 to 8 carbon atoms), organotin carboxylic acid, its salt (alkali metal, alkali salts of earth metals, copper, zinc, aluminum, etc.) or their esters (ester part includes alkyl, aryl, aralkyl having 1 to 8 carbon atoms) or organotin thioalkanoic acid ester (ester part contains 1 to 8 carbon atoms) (containing 2 alkyl groups), and mono-, di-, and tri-organotin compounds, as well as tetra-organotin compounds, respectively. Organic groups include alkyl groups having 1 to 8 carbon atoms (methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tertiary butyl, pentyl, isopentyl, neopentyl, hexyl, octyl, 2-ethylhexyl, 1,1,3 .3-tetramethylbutyl, etc., butyl and octyl are particularly preferred), carbon number 3
~7 cycloalkyl (including cyclopropyl, cyclopentyl, cyclohexyl, cycloheptyl, etc., with cyclohexyl being particularly preferred), phenyl, substituted phenyl (the substituent is preferably an alkyl group having 1 to 8 carbon atoms) refers to a hydrocarbon group having 1 to 18 carbon atoms such as aralkyl (benzyl, benzhydryl, trityl, 2-phenylethyl, neophyl, etc.).

Specific examples of these organic tin compounds include dimethyltin oxide, dibutyltin oxide, dioctyltin oxide, bistributyltin oxide, monobutyltin oxide, monobutyltin oxide, monomethylstannic acid, monooctyltin oxide, and monophenyltin oxide. Organotin oxides such as acids, organotin sulfides such as dibutyltin sulfide and diphenyltin sulfide, organotin halides such as monobutyltin trichloride, dibutyltin dipromide, and monophenyltin tripromide, and organotin sulfates such as diptyltin sulfate. ,
Dimethyltin diacetate, dibutyltin diacetate, dioctyltin diacetate, triphenyltin acetate,
dibutyltin dilaurate, dioctyltin dilaurate,
Organotin carboxylic acid esters such as dibutyltin maleate, organotin thioalkanoic acid esters such as diptyltin thioglycolate, dibutyltin β-mercaptopropionate, organotin mercaptans such as dibutyltin dithiol,
Examples include organic tin alkoxides such as dioctyltin dimethoxide, dioctyltin dibutoxide, and dibutyltin diphenoxide, and tetraalkyl or aryltins such as phenoxide, tetrabutyltin, and tetraphenyltin.
Of course, it is not limited to these.

These organic tin compounds are contained in oil-soluble substances, such as liquid mixtures obtained by manufacturing organic tin compounds or liquid mixtures obtained by reaction using organic tin compounds as catalysts. These are usually organic solvents (aromatic hydrocarbons such as benzene, toluene, xylene, methanol,
Ethanol, propatool, isopropyl alcohol,
Alcohols such as butanol, hexane, heftane,
These include aliphatic hydrocarbons such as cyclohexane, ketones such as cyclohexanone, methyl ethyl ketone, and methyl isobutyl ketone, and halogenated hydrocarbons such as chloromethane, dichloroethane, chloroform, carbon tetrachloride, and chlorobenzene, which do not contain water. You can stay there. ) dissolved or suspended in Note that when the reactant is liquid, there is no need to further use these solvents.

Moreover, these solvents can be appropriately selected from industrially advantageous solvents in accordance with the purpose of the present invention.

Substances that make the organotin compounds contained in oil-soluble substances oil-insoluble or poorly soluble include sulfonic acid compounds, sulfamic acid compounds, or their salts (metal salts,
amine salts, etc.) are used.

Sulfonic acid compounds include sulfuric acid, methanesulfonic acid, ethanesulfonic acid, 2-hydroxyethanesulfonic acid, propanesulfonic acid, butanesulfonic acid, benzenesulfonic acid, toluenesulfonic acid, benzenedisulfonic acid, toluenedisulfonic acid, etc. Acid compounds include sulfamic acid and nitridodisulfamic acid, and metal salts include alkali metal salts such as sodium salts and potassium salts, alkaline earth metal salts such as calcium salts, barium salts, and magnesium salts, and even zinc salts. Examples of the amine salts include ammonium salts and aliphatic amine salts such as triethylamine salts and triethanolamine salts.

From an industrial point of view, sulfuric acid, sulfamic acid and their sodium salts are advantageously used.

The oil-insoluble or sparingly soluble organotin compound is formed by stirring an organotin compound and a sulfonic acid compound, a sulfamic acid compound, or a salt thereof at room temperature or under heating. The amount of the sulfonic acid compound, sulfamic acid compound, or salt thereof to be used may be such as to form an oil-insoluble or poorly soluble organotin compound, and is usually 1 to 10 times the amount of the organotin compound.

The oil-insoluble or sparingly soluble organotin compound thus produced may be water-soluble, or may form a micelle compound that is insoluble or sparingly soluble in water and organic solvents. This compound can be easily removed by extraction with water. - For boat fishing, it is possible to separate the organic layer containing oil-soluble substances into an aqueous layer containing oil-insoluble or poorly soluble organotin compounds, and remove the organotin compounds from the oil-soluble substances by removing the aqueous layer. can.

Furthermore, if necessary, the filtrate obtained by filtration or the supernatant obtained by centrifugal sedimentation can be extracted with water.

The concentration of the organotin compound in the filtrate thus obtained can be reduced by repeatedly carrying out the method of the present invention, if necessary, but it is preferable to reduce the concentration of the organotin compound according to the permissible concentration.

The reaction product liquid from which organotin compounds have been removed by the method of the present invention can be used as the target product as it is, or the target product can be isolated and purified by conventional methods such as recrystallization, distillation, and column chromatography. Can be done.

〔Example〕

EXAMPLES The present invention will be explained in more detail with reference to Examples below, but the present invention is not limited to these in any way.

Example 1 A 15% solution was added to 830 g of a toluene solution containing 0.3 mol of bistributyltin oxide and having a coloring degree of Gardner's tin oxide of 8.
Sulfamic acid aqueous solution (0.61 as sulfamic acid)
mol) was added thereto, and the mixture was stirred at room temperature for 10 minutes. The reaction product was separated into three layers. The lowermost layer was separated, 20% hydrochloric acid was added, and the mixture was stirred at room temperature for 5 minutes. The lower layer was separated and dehydrated under reduced pressure to obtain oily tributyltin chloride. The yield was 98%, and the degree of coloration was Gardner level 3.

On the other hand, the toluene solution before treatment with sulfamic acid was
After treating with 0% hydrochloric acid to convert bistributyltin oxide to tributyltin chloride, the oil layer was separated and toluene was concentrated. The tributyltin chloride obtained was black and could not be indicated by Gardna No. 1. The degree of coloration of bistributyltin chloride obtained by distilling it under reduced pressure showed a Gardner barrier of 2, but the purity was 86% due to thermal decomposition.

Example 2 Dibutyltin dichloride with a coloring degree of Gardner size 4 of 0.2
A 30% sodium sulfamate aqueous solution (0.45 mol as sodium sulfamate) was heated at 60° C. for 30 minutes. Reactants: 3g of decolorizing carbon, 500w of water
After stirring, 20% hydrochloric acid was added to the mother liquor from which the decolorizing charcoal had been filtered off, and the mixture was heated at 60° C. for 10 minutes to separate dibutyltin dichloride into a lower layer. The lower layer was separated, dehydrated under reduced pressure, and reduced to 0.
196 moles of dibutyltin dichloride were recovered. The yield was 96%, and the degree of coloration was Gardner 1. For comparison, the raw material was vacuum distilled, and due to thermal decomposition, the purity of the product obtained was 93% (tributyltin chloride was the main impurity), and the yield was 85%. The degree of coloring is Gardner! It was lhl.

Example 3 80 g of a 3% aqueous sulfuric acid solution was added to 550 g of a heptane solution containing 0.83 mol of benzyl salicylate synthesized using 1 g of dimethyltinmercaptopropionic acid as a catalyst.
The mixture was stirred at 40°C for 30 minutes. When the heptane layer was separated and the heptane was concentrated, the tin catalyst content in benzyl salicylate was found to be 40 ppm, and the product was directly distilled under reduced pressure to obtain a product of benzyl salicylate. Yield 94.8%, coloring degree AP
It was HA50'.

Example 4 50 g of a 3% potassium benzenedisulfonate aqueous solution was added to the reaction product obtained by heating 0.1 mol of phthalic anhydride, 0.3 mol of methanol, and 1 g of tricyclohexyltin bromide to synthesize dimethyl phthalic acid. After stirring for several minutes, an oil layer and an aqueous layer were separated. After dehydrating the oil layer under reduced pressure, the catalyst content was analyzed and found to be 58 ppm. When 20% hydrochloric acid was added to the aqueous layer, tricyclohexyltin chloride precipitated immediately.

Example 5 0.5 mol of roseoxybenzoic acid, 0 benzyl alcohol
．． A mixture of 6 mol and 2 g of diptyltin oxide is added to 1
50 g of a 5% aqueous nitridodisulfonic acid solution and 200 ml of trichloroethane were added to the reaction product obtained by heating to 80° C., and the mixture was heated and stirred at room temperature for 10 minutes. After separating the two layers and concentrating the oil layer, the catalyst content in the obtained benzyl roseoxybenzoate was 20 ppm.

When 20% hydrochloric acid was added to the aqueous layer, dibutyltin dichloride crystals were precipitated. After filtering and drying, 0.8 g was obtained. Analysis revealed that it contained 0.6 g of dibutyltin chloride.

Example 6 A mixture of 0.5 mol of phenyl salicylate, 0.8 mol of butanol, and 1 g of dioctyltin dibutoxide was mixed with 10
The reaction was heated at 0°C. After removing excess butanol, 40 g of a 5% aqueous nitride disulfonic acid solution and 100 ml of xylene were added, followed by stirring at room temperature for 15 minutes. After separating the two layers and concentrating the oil layer, no catalyst was detected in the butyl salicylate obtained. After treating the aqueous layer with decolorizing charcoal, 15% hydrochloric acid was added and the precipitated crystals were collected by filtration and dried to recover 0.8 g of dioctyltin dichloride.

Example 7 2.6 Methyl di-tertiary-butylphenylpropionate 0
．． 3 moles of dodecyl alcohol, 0.31 moles of dodecyl alcohol, and 2 g of motuputyl tin oxide as a catalyst were added, and the mixture was reacted at 180° C. for 5 hours. After the reaction, 200 m of chlorobenzene
1. Add 5 g of methanesulfonic acid and 100 ml of water,
After stirring at room temperature for 30 minutes, the oil layer was separated, and the tin content in dodecyl 2,6-di-tertiary-butylphenylpropionate obtained after distilling off chlorobenzene was 25 ppm.

〔Effect of the invention〕

As is clear from the description of the specification including the examples, according to the method of the present invention, the organotin compound is made into an oil-insoluble or poorly soluble organotin compound, which makes it extremely easy to remove or purify the organotin compound from an oil-soluble substance. Can be done.

Claims (1)

[Claims] (1) The organotin compound contained in the oil-soluble substance is treated with a sulfonic acid compound, sulfamic acid compound, or a salt thereof to form an oil-insoluble or sparingly soluble organotin compound, and then extracted with water. A method for removing organic tin compounds.