JPH0410459B2 - - Google Patents

Description

[Detailed description of the invention]

TECHNICAL FIELD This invention relates to a process for carboxylic acid lanthanide salts. (Prior Art) Conventionally developed methods for producing carboxylic acid salts of metals other than lanthanides include a method using water as a reaction medium and a method in which the reaction is carried out under anhydrous conditions in an organic solvent. However, when producing lanthanide salts of carboxylic acids, the method using water significantly reduces the yield because a small amount of the lanthanide carboxylic acid salts produced dissolves in water, and also produces a product that is substantially water-free. This requires sufficient drying, which is disadvantageous as an industrial production method. Furthermore, when the reaction is carried out in an organic solvent under anhydrous conditions, the desired salt may not be produced at all, and even when the same carboxylic acid is used, reproducible synthesis is impossible. There are some inconveniences. (Object of the Invention) In view of the above-mentioned conventional techniques, an object of the present invention is to provide a method for efficiently producing a useful carboxylic acid lanthanide salt in an industrial manner. (Structure of the Invention) The method for producing the carboxylic acid _lanthanide salt of the present invention has the following general formula: group hydrocarbon group, n is 1
Or 2. It consists of reacting at least one type of carboxylic acid represented by and at least one type of lanthanide compound selected from oxides, hydroxides, and carbonates of lanthanides including lanthanum in the presence of water in an organic solvent. . The carboxylic acid of general formula () used in the present invention is a saturated or unsaturated aliphatic or aromatic mono- or dicarboxylic acid, and a hydroxycarboxylic acid substituted with at least one hydroxyl group in one molecule of these carboxylic acids. Also includes acids. Specific examples include acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, acrylic acid, methacrylic acid, crotonic acid, oleic acid, sorbic acid, β-hydroxybutyric acid, etc. Aliphatic monocarboxylic acids; aliphatic dicarboxylic acids such as itaconic acid, oxalic acid, malonic acid, succinic acid, adipic acid, maleic acid, fumaric acid; aromatic monocarboxylic acids such as benzoic acid and toluic acid; phthalic acid, etc. Examples include aromatic dicarboxylic acids. These carboxylic acids may be used alone or in combination of two or more. The lanthanide compounds used in the present invention include:
Specifically, La, Ce, Pr, Nd, Sm, Eu, Gd,
One or more types selected from oxides, hydroxides, and carbonates of Tb, Dy, Ho, Er, Tm, Yb, and Lu can be used, and in some cases, two or more types of lanthanides are included. It is also possible to use a composite oxide. The lanthanide compounds used in the present invention include:
Ordinary powdery solids are preferred; powdery forms are convenient for charging into a reactor, are easily stirred and dispersed in an organic solvent, and can uniformize the reaction with the carboxylic acid. The ratio between the total amount of carboxylic acids represented by the general formula () used in the present invention and the total amount of lanthanide compounds is such that the total amount of carboxylic acids is equal to or more than the salt-forming equivalent, preferably 1 of the salt-forming equivalent, relative to the total amount of the lanthanide compounds.
~1.2 times the amount. If the total amount of carboxylic acid is less than the salt-forming equivalent, unreacted lanthanide compounds will remain in the produced carboxylic acid lanthanide salt, reducing product purity. However, if a monomer such as methyl methacrylate or styrene is used as an organic solvent and the solution is directly subjected to the polymerization reaction, the total amount of carboxylic acids should be equal to or less than the equivalent of salt formation with respect to the total amount of lanthanide compounds, and unreacted lanthanide compounds should be It is preferable to separate by heating. Furthermore, when using a carboxylic acid having polymerizability such as acrylic acid or methacrylic acid as the carboxylic acid of general formula (), it is preferable to add a polymerization inhibitor such as hydroquinone or hydroquinone monomethyl ether. Therefore, it does not cause any hindrance to the salt formation reaction. The organic solvent used in the present invention is not particularly limited as long as it is inert and does not react with the carboxylic acid and lanthanide compound of general formula (). For example, organic solvents such as toluene, xylene, benzene, hexane, heptane, ether, tetrahydrofuran, dioxane, carbon tetrachloride, methylene chloride, acetone, methyl ethyl ketone, and liquid monomers such as methyl methacrylate, methyl acrylate, and styrene can be used. can. These specific organic solvents have the characteristic that they hardly dissolve the carboxylic acid lanthanide salt, so that the produced salt can be easily separated by a physical separation operation such as filtration.
In addition, to describe individual features, when using a solvent that is compatible with water, such as tetrahydrofuran or acetone, it is necessary to increase the amount of water present in the reaction system, but on the other hand, the effect of the water produced by the reaction is small. This makes it easier to control the reaction. Using a solvent that is not compatible with water and is azeotropic with water, such as toluene, hexane, or methyl methacrylate, allows dehydration to be carried out azeotropically after the reaction is completed, which is advantageous compared to using only water as the reaction medium. It is. In addition, when liquid monomers such as methyl methacrylate, methyl acrylate, and styrene are used as solvents, they can be used as they are as raw materials for solution polymerization containing carboxylic acid lanthanide salts, thereby shortening the polymer production process including raw material preparation and polymerization operations. . The amount of organic solvent used in the present invention may be any amount that can uniformly disperse the lanthanide compound in the reaction system, and in particular, the amount of the organic solvent used can be
The amount should be 2 to 15 times the total amount of carboxylic acid to avoid inducing local reactions with the carboxylic acid, to efficiently remove the reaction heat, and to reduce the dispersion of the produced carboxylic acid lanthanide salt. This is preferable because it does not cause problems such as enveloping unreacted lanthanide compounds. The carboxylic acid lanthanide salt production reaction according to the present invention is characterized by being carried out in the presence of water in an organic solvent, but the amount of water used varies depending on the type of carboxylic acid that is the reaction raw material. It has a close relationship with compatibility with water and acidity. That is, the carboxylic acid used has high compatibility with water,
The more acidic the water, the less water is needed. More specifically, when using a carboxylic acid that is difficult to miscible with water and has a carbon number of 6 or more, 1 equivalent of the carboxylic acid is used.
It is preferable that water be present in an amount of 0.1 mol or more per equivalent of the carboxylic acid when using a carboxylic acid that is easily compatible with water having 5 or less carbon atoms. Among these, when using a carboxylic acid having 3 or less carbon atoms, if the amount of water present is less than 0.1 mol, a rapid reaction will occur due to the water produced by the reaction in the late stage of the reaction, and the reaction product will solidify. Put it away. Therefore, it is possible to control the reaction rate by allowing the reaction to proceed while keeping the amount of water in the reaction system constant while dehydrating, but this requires special equipment and complicated operations. As mentioned above, per equivalent of carboxylic acid
Preferably, 0.1 mole or more of water is present.
In addition, when using a carboxylic acid having 4 or more carbon atoms, the salt formation reaction may not proceed at all, especially if the amount of water present is less than 0.1 mol per equivalent of the carboxylic acid.
Alternatively, the reaction rate becomes slow, which is not preferable. On the other hand, when using a carboxylic acid that is difficult to mix with water and has a high acid strength, if the water content is too small, the reaction will not occur, and if it is too large, the reaction will proceed rapidly. A water amount of 8 moles is preferred. By taking such circumstances into consideration, the amount of water used in the present invention can be selected from a wide range. The reaction temperature of the carboxylic acid lanthanide salt production reaction according to the present invention is preferably 40° C. or higher and lower than the boiling point of the organic solvent used. Reaction temperature is 40℃
If the temperature is below the boiling point of the organic solvent, the reaction rate will be low, and if the temperature is above the boiling point of the organic solvent, it will naturally become uneconomical due to loss of solvent. Although the reaction can be carried out under normal pressure, reduced pressure or increased pressure, it is preferable to carry out the reaction under normal pressure depending on the selection of the solvent type. (Example) Hereinafter, the present invention will be explained in more detail by showing specific examples and comparative examples. In addition, in Examples and Comparative Examples, parts indicate parts by weight, and % indicates weight %. Example 1 168 parts of neodymium oxide was suspended in 860 parts of toluene,
A mixed solution of 314 parts of isobutyric acid and 70 parts of water was added dropwise over about 10 minutes while stirring, and then the reaction was carried out at 60°C for 2 hours. The reaction was completed in approximately 1 hour. The resulting slurry was filtered under reduced pressure using Toyo Paper No. 2 paper, and the residue was dried at 70° C. and normal pressure for 4 hours to obtain 385 parts of neodymium isobutyrate powder. The purity was 99%. Comparative Example 1 168 parts of neodymium oxide was suspended in 860 parts of toluene,
Water was azeotropically removed using a decanter at 60° C. under reduced pressure, and 314 parts of isobutyric acid was added dropwise over about 30 minutes while continuously removing water, followed by reaction for 10 hours.
As a result, almost no salt production reaction occurs,
All that was removed was neodymium oxide. In addition, almost no water was distilled out. Example 2 A reaction was carried out in accordance with Example 1 using acetic acid instead of isobutyric acid and a mixture of 210 parts of acetic acid and 60 parts of water to obtain 311 parts of neodymium acetate powder. Example 3 195 parts of succinic acid and 100 parts of water were dissolved in 710 parts of acetone, 168 parts of neodymium oxide was added over 10 minutes while stirring, and the mixture was heated to about 55°C and reacted for 10 hours.
Post-treatment was carried out in accordance with Example 1, and 302 parts of neodymium succinate powder was obtained. Comparative Example 2 Example 2 using 0.1 part of water instead of 60.0 parts of water
When the reaction was carried out according to the method described above, a reaction occurred rapidly at the end of the dropwise addition of the acetic acid/water mixture, resulting in solidification. Comparative Example 3 A reaction was carried out according to Example 1 using water instead of toluene, and 215 parts of neodymium isobutyrate powder was obtained. Example 4 415 parts of benzoic acid and 350 parts of water were dissolved in 510 parts of acetone, 168 parts of neodymium oxide was added over 10 minutes while stirring, and the mixture was heated to about 55°C and reacted for 2 hours according to Example 1. After post-treatment, 447 parts of neodymium benzoate powder was obtained. Comparative Example 4 415 parts of benzoic acid was dissolved in 860 parts of toluene at 60°C, 168 parts of neodymium oxide was added over 10 minutes with stirring, the mixture was heated at 60°C and reacted for 10 minutes, and then the solution was dissolved according to Example 1. Upon treatment, the resulting powder was a mixture of neodymium oxide and benzoic acid. Example 5 168 parts of neodymium oxide was suspended in 860 parts of toluene,
While stirring, add 142 parts of methacrylic acid, 99 parts of acetic acid, and water.
A homogeneous mixture of 60 parts of hydroquinone monomethyl ether and 0.5 parts of hydroquinone monomethyl ether was added dropwise over about 20 minutes, and then heated at 60℃ for 2 hours.
Allowed time to react. The resulting slurry was post-treated in accordance with Example 1 to obtain 352 parts of acetic acid/neodymium methacrylate double salt. Examples 6 to 16 Various lanthanide salts were synthesized in the same manner as in Example 1 using the raw materials shown in the table below. The results are shown in the table.

[Table] (Effects of the Invention) In the production method of the present invention, the reaction between a carboxylic acid and a lanthanide compound is carried out in the presence of water in an organic solvent, so the yield of a lanthanide salt of a carboxylic acid is significantly improved. This method is extremely advantageous as an industrial method for producing carboxylic acid lanthanide salts, which are useful as auxiliary agents for resins, ionic crosslinking agents, and the like.

Claims (1)

[Claims] 1 General formula: R(-COOH) _o (wherein R is a saturated or unsaturated aliphatic or aromatic hydrocarbon group which may be substituted with a hydroxyl group, n is 1
Or 2. ) and at least one lanthanide compound selected from oxides, hydroxides and carbonates of lanthanides containing lanthanum in the presence of water in an organic solvent. Characteristic method for producing carboxylic acid lanthanide salt.