NO770107L - PROCEDURES FOR THE PREPARATION OF MANGANESALTS OF ORGANIC ACIDS. - Google Patents

Description

Process for the production of manganese salts of

organic acid.

The invention relates to an improved process for producing manganese salts of organic acids. More particularly, it relates to a process for producing manganese salts by reacting manganese (II) oxide with organic acids in the presence of a formic acid catalyst.

Manganese salts of organic acids are used as drying agents in paints, varnishes and printing inks, as stabilizers in various resins, catalysts for chemical processes and as additives to fuel oil, lubricating oil and lubricating grease.

Manganese salts of organic acids can be produced by three process types, namely double-composition, reactions metal-organic acid, and reactions metal-oxide-organic acid.

In the double-composition processes that are in extensive use, an aqueous solution of a water-soluble manganese(II) salt, such as e.g. manganese sulfate, reacted with an aqueous solution of the sodium salt of an organic monocarboxylic acid.

The reaction is usually carried out with an organic solvent which is not miscible with water, for example mineral spirits, forming a solution of manganese salt in organic solvents and a solution of the by-product sodium sulphate in the water phase. The turnover takes place according to the following equation:

M SO. + 2Na00CR > M (OOCR) ~ + Na„SO.

n 4 n 2 2 4 When the process is used technically, the double decomposition method has the disadvantage that it forms relatively large amounts of aqueous sodium sulphate solution as a by-product, which

largely limits productivity and presents pollution problems. In addition, it is very difficult and expensive to free the manganese salt completely from the by-product sodium sulphate.

The reaction of manganese with an organic monocarboxylic acid to a manganese salt and hydrogen is shown in the following equation:

While this method has none of the disadvantages of the double decomposition process, it requires precautions to ensure that the evolved hydrogen can be safely removed.

The manganese salt can also be produced by smelting processes where manganese oxide is reacted with an organic acid to a manganese salt in.: water, as according to the following equation:

The smelting process does not have the disadvantages of double decomposition or the reaction between metal and organic acid. However, the process is uneconomical in practice on an industrial scale, if the manganese oxide used is not at least 98% pure, because when less pure metal is used, the yields of manganese salt are low, even when the reaction times are very long. Even when manganese oxide of high purity is used for the smelting process, a satisfactory salt yield is only achieved after a long reaction time.

According to the invention, it has been found that manganese salts of organic acids can be produced with excellent yield during: a relatively short reaction time by reacting manganese(II) oxide with organic monocarboxylic acids in the presence of formic acid catalyst.

While formic acid is the preferred catalyst and the one most often used according to the method of the invention, other substances which can give off formic acid under the conditions of the present invention can also be used. Such compounds include ammonium formate, amine formate such as diethylamine formate and lower formate such as methyl formate, ethyl formate and isopropyl formate as well as mixtures of these.

Using as little as 1% formic acid catalyst, based on the weight of manganese in the manganese oxide, gives a significantly improved yield of manganese salt during a shorter reaction time. In most cases, from 2 to 8% formic acid catalyst is used based on the weight of manganese in the manganese oxide, because this amount gives the highest yield of manganese salt on

shortest time. Using larger amounts of catalyst does not provide additional benefits. When formic acid or a compound capable of emitting formic acid is used to catalyze the reaction between manganese oxide and an organic monocarboxylic acid, yields of 95 to 99 percent manganese salt are obtained in 10 to 50% of the time required when the reaction is carried out without a formic acid catalyst or in the presence of an equivalent amount of acetic acid.

While manganese oxide of any degree of purity can be used for the process of the invention, it is an advantage that the compound has at least 98% degree of purity.

The best results are obtained when the manganese oxide contains

at least 99% M 0.

n

Many different organic monocarboxylic acids can be used in connection with the method of the invention. They include aliphatic acids, alicylic acids, aromatic acids, and mixtures of these. The preferred monocarboxylic acids are saturated and unsaturated aliphatic and alicyclic monocarboxylic acids with from 5 to 22 carbon atoms. Examples of such preferred acids are pentanoic acid, n-hexanoic acid, n-heptanoic acid, n-nonanoic acid, n-decanoic acid, lauryl acid, stearic acid, arachidic acid, behenic acid, 2-methylbutanoic acid, 2-ethyl-butanoic acid, 2-ethyl-4 -methylpentanoic acid, 2-ethylhexanoic acid, trimethylacetic acid, 2,2,4,4-tetramethylpentanoic acid, 2-isopropyl-2,3-dimethylbutanoic acid, 2-propyl'-4-methylpentanoic acid, 2-propylheptanoic acid, 2-methylnonanoic acid . -ethyl-1-3-propylforyl acid, 10-undecenoic acid, oleic acid, arucinic acid, brassidic acid, napthenic acid, resin acid and terpenic acids.

A single monocarboxylic acid or a mixture of two or more can be used in the present process. Technical mixtures of acids that can be used are tall oil fatty acids, linseed oil fatty acids, and other fatty acids from drying or semi-drying oils as well as Cg-C^g oxo acids which can be produced by oxidation of the corresponding aldehydes according to the U.S. Patent No. 3,124,475, and C 8 -C 11 trialkyl acetic acids.

The reaction between manganese(II) oxide and

the organic monocarboxylic acid is advantageously carried out in the presence of water. The water does not participate in the reaction but helps to distribute the catalyst evenly in the reaction mixture. The water can be added before, during or after adding the catalyst. Alternatively, an aqueous solution of the catalyst can be added to the reaction mixture. The added amount of water is usually between 10 and 80 percent by weight of the manganese in the manganese oxide. In addition to water, the reaction mixture contains water which is formed as a by-product during the reaction.

The formic acid-catalyzed reaction between manganese oxide and the organic monocarboxylic acid is usually carried out in the presence of an inert organic solvent which is not miscible with water, preferably an aliphatic or aromatic hydrocarbon or chlorinated hydrocarbon. Suitable solvents are hydrocarbons such as benzene, toluene, xylene, ethylbenzene, dipentene, turpentine, hydrocarbons from -.: petroleum such as petrol, mineral turpentine, patrolleum, mineral oil, fuel oil and aromatic petrol fractions and such chlorinated hydrocarbons as carbon tetrachloride, ortho-dichlorobenzene, mono-chlorotoluene, ethylene dichloride and perchlorethylene. If desired, mixtures of these solvents can be used.

In the method according to the invention, a formic acid catalyst is added to the reaction mixture containing manganese oxide, at least one organic monocarboxylic acid, and an inert organic solvent, at a temperature below the boiling point of water. Since the reaction is exothermic when the catalyst is added at temperatures above 70°C, the catalyst is preferably added at between 15°C and 60°C. The reaction mixture is then heated to a temperature between 90 and 115°C until most of the manganese oxide has been converted. The reaction mixture can then be heated to

remove the water and filter to remove unreacted manganese oxide and other solid impurities. The formed manganese salt-

resolution can e.g. is used as a fuel additive or as a drying agent in coatings without further purification or treatment other than setting the manganese content to the desired concentration.

Manganese salt solutions produced by the process according to the invention generally contain from 5 to 12 weight percent manganese as metal. The metal content

is limited for a particular salt solution by the molar weight of the monocarboxylic acid used and the viscosity required in the final solution. It is often necessary to use a peptizer to reduce the viscosity of the manganese salt solution. Among the additives that can be used for this purpose are alkyl acid phosphates described in U.S. Pat. Patent No. 2,456,824 and polyoxyalkylene glycols such as dipropylene glycol and tripropylene glycol described in U.S. Pat. patent No. 2,807,553.

The invention is further illustrated by the following examples:

Example 1

A mixture of 58.8 g manganese oxide (99% MnO), 259 g 3,5,5-trimethylhexanoic acid and 175 g mineral turpentine (boiling point 160 - 200°C) was heated to 75°C. A solution of 1.1 g of 90% formic acid in 20 g was added and the mixture was heated to reflux temperature (99-103°C). After the reaction mixture had been heated at this temperature for 2.5 hours, most of the manganese oxide had reacted. 20 g of butylic acid phosphate was added to the reaction mixture to reduce the viscosity. The resulting mixture was heated to 130°C to remove water. After adding mineral spirits to replace what was lost during the drying step, the reaction mixture was filtered to remove impurities and unreacted manganese oxide.

A solution of manganese 3,5,5-trimethylhexoate in mineral spirits was obtained, containing 9% by weight of manganese as metal. The yield of manganese trimethylhexanoate was 95%. The manganese itrimethylhexanoate solution was stable, and did not emulsify easily when shaken with an equal volume of water.

Example 2

A blanching of 65.3 g of manganese oxide

(99% MnO), 216 g of 3,5,5-trimethylhexanoic acid, 65.5 g of 2-ethylhexanoic acid, and 145 g of mineral spirits (b.p. 160-200°C) were heated to 75°C. A catalyst solution prepared by adding 1.3 g of 90% formic acid and 1.5 g of 28% ammonium hydroxide to 37.2 g of water was added. The reaction mixture was heated to reflux temperature (99-104°C) and held at this temperature for 4 hours. After this, most of the manganese oxide had reacted. 25 g of butyl acid phosphate was added to the reaction mixture to reduce the viscosity. The mixture was heated to 130°C to remove water. After mineral spirits were added to replace what was lost during the drying step, the mixture was filtered to remove impurities and unreacted manganese oxide.

484 g of solution of mixed manganese soap of 3,5,5-trimethylhexanoic acid and 2-ethylhexanoic acid in mineral turpentine was obtained:). which contained 10% by weight of manganese as metal. The yield of manganese soap was 96 f>8%.

Example 3

A mixture of 65.3 g manganese oxide (99% MnO), 216 g 3,5,5-trimethylhexanoic acid, 65.5 g 2-ethylhexanoic acid, and 145 g mineral turpentine (bp. 160 - 200°C) was heated to 75° C. A catalyst solution prepared by adding 2.8 g of 90% formic acid to 25 g of water was added. The reaction mixture was heated to reflux temperature and held at this temperature for 50 minutes. 25 g of butyl acid phosphate was added to the mixture to reduce the viscosity. The resulting mixture was heated to 130°C to remove water, and mineral spirits was added to replace that lost during the drying step. After filtration, a solution of mixed manganese soap of 3,5,5-trimethylhexanoic acid and 2-ethylhexanoic acid in mineral turpentine containing 10% by weight of manganese as metal was obtained. The yield of manganese soap was 95.5%.

Example 4

Example 3 was repeated and a solution of 4.2 g of 90% formic acid in 25 g of water was used as catalyst. After the reaction mixture had been heated at reflux temperature for 1 hour, a solution of mixed manganese soap of 3,5,5-trimethylhexanoic acid and 2-ethylhexanoic acid in mineral turpentine containing 10% by weight of manganese as metal was obtained. The yield of manganese soap was 95.0%.

Example 5

Example 3 was repeated and a solution of 3.0 g of 97% ethyl formate in 30 g of water was used as catalyst. After the reaction mixture had been heated at reflux temperature for 1.5 hours, a solution of mixed manganese soap of 3,5,5-trimethylhexanoic acid and 2-ethylhexanoic acid in mineral turpentine containing 10% by weight of manganese as metal was obtained. The yield of manganese soap was 9 5.8%.

Example 6

To a mixture of 39.2 g of manganese oxide (99% MnO), 273.5 g of naphthenic acid (acid number 224 mg. KOH/gram), and 185 g of mineral turpentine (bp. 160-200°C) at 25°C, was added a catalyst solution prepared by adding 1.0 g of 90% formic acid to 30 g of water. This mixture was heated at reflux temperature (104-108°C) for 1 hour.

After addition of 12.5 g of butyl acid phosphate, the mixture was heated to 130°C to drive off water. Mineral spirits were added to replace what was lost and the reaction mixture was filtered. 492 g of solution of manganese naphthenate in mineral turpentine containing 6% by weight manganese as metal was obtained. The yield of manganese naphthenate was 9 8.4%.

Example 7

A catalyst solution prepared by adding 1.0 g 90 % formic acid to 30 g of water. The mixture was heated at reflux temperature for 1 hour.

After adding 20 g of tripropylene glycol, the mixture was heated to 130°C to remove the water. Mineral spirits were added to replace what was lost during the drying step and the reaction mixture was filtered.

486 g of solution of manganese-2-ethylhexanoate in mineral turpentine containing 6% by weight of manganese as metal was obtained. The yield of manganese 2-ethylhexanoate was 9 7.2%.

Example 8

To a mixture of 6 5.3 g manganese oxide 9 9%MnO) and 26 2.5 g

Oxo isooctanoic acids, which consisted mainly of 3,4-, 3,5- and 4,5-dimethylhexanoic acids and 3- and 5-methylheptanoic acids, 165 g of naphtha, containing 9 3.8% aromatic substances, 3.5 % paraffin, and 2.7% naphthenes and which had a boiling point range of 160-165°C. A catalyst solution prepared by adding 2.8 g of 90% formic acids to 10 g of water was added to the reaction mixture at 25°C. The mixture was heated at the reflux temperature (99-103°C) for 1 hour.

After adding 25 g of butyl acid phosphate, the mixture was heated to 130°C to drive off water. Aromatic gasoline was added to replace that lost during the drying step and the reaction mixture was filtered.

A solution of 479 g of manganese octanoate in aromatic petrol was obtained, containing 10 weight percent manganese as metal. The yield of manganese octanoate was 95.8%.

Comparative example A.

A mixture of 5.8.8 g of manganese oxide (99% MnO), 259 g of 3,5,5-trimethylhexanoic acid and 175 g of mineral turpentine (bp. 160 - 200°C) was heated to 75°C. 20 g of water was added and the mixture heated at reflux temperature (99-103°C) for 8 hours.

20 g of butyl acid phosphate was added and the reaction mixture heated to 130°C to remove water.

After mineral spirits were added to replace what was lost during the drying step, the reaction mixture was filtered.

450 g of solution of manganese-3,5,5-trimethylhexanoate in mineral turpentine was obtained, containing 9 weight percent manganese as metal. The yield of manganese 3,5,5-

trimethylhexanoate was 90%.

Comparative example B

A mixture of 58.8 g of manganese oxide ('99%' MnO)-., 259 g of 3,5,5-trimethylhexanoic acid, and 175 g of mineral turpentine (b.p. 160-200°C) was heated to 75°C. A catalyst solution prepared by adding 1.4 g of glacial acetic acid to 20 g of water was added, and the reaction mixture was heated to ten labake temperatures. After 5 hours of boiling at this temperature, the degree of conversion of manganese oxide to manganese 3,5,5-trimethylhexanoate was 72% according to chemical analyses. The reaction mixture was heated at reflux temperature

for another 3 hours.

After adding 20 g of butyl acid phosphate, the reaction mixture was heated to 130°C to remove water, and after mineral spirits was added to replace that lost during the drying step, the reaction mixture was filtered.

A solution of manganese 3,5,5-trimethylhexanoate in mineral terpentine was obtained. containing 9 weight percent manganese as metal. The yield of manganese 3,5,5-trimethyl hexanoate was 90.4%.

The data given in the examples are summarized in the following table.

From the figures in the preceding table, it will be seen that formic acid, ammonium formate and ethyl formate are effective catalysts for the conversion between manganese oxide and

organic acids. Use of these catalysts gave a significantly higher initial yield of manganese salts in a much shorter time than without a mauric acid catalyst or in the presence of an equivalent amount of acetic acid.

Claims (1)

1, Process for the production of manganese salts, characterized in that manganese-(II),-oxS.yd is brought into contact with at least one organic monocarboxylic acid in the presence of a formic acid catalyst. 2, Method as stated in claim 1, characterized in that at least 1% formic acid catalyst is used, based on the weight of manganese in the manganese oxide, 3T Method as stated in claim 1, characterized in that 2 to 8% formic acid catalyst is used based on the weight of manganese in the manganese oxide, 4. Method as stated in claim 1 characterized in that the formic acid catalyst is selected from formic acid, ammonium formate, amine formates, lower alkyl formates and mixtures thereof. 5. Method as stated in claim 1, characterized in that the manganese oxide is brought into contact with the organic monocarboxylic acid in the presence of a formic acid catalyst, water and an inert organic solvent which is not miscible with water. 6. Process as stated in claim 1, characterized in that the organic monocarboxylic acid is aliphatic or alicyclic monocarboxylic acid with 5 to 2 2 o atoms, 1, Method as stated in claim 1, characterized in that a), at least 1% formic acid catalyst based on the weight of manganese in the manganese oxide is added to a reaction mixture of manganese oxide, at least one organic monocarboxylic acid and an organic solvent not miscible with water, at a temperature below boiling point of water, b) the reaction mixture is heated at a temperature between 90 and 115°C until substantially all manganese oxide has been converted and c) a manganese salt solution containing from 5 to 12% by weight of marig^ . from which metal is extracted. 8, Method as stated in claim 7, characterized in that during step 7a) from 2 to 8% catalyst is added to the reaction mixture, based on the weight of manganese in the manganese oxide. 9, Method as specified in claim 7, characterized in that during step a) an aqueous solution of formic acid catalyst is added to the reaction mixture, 10, Method as stated in claim 7, characterized in that during step a) a formic acid catalyst is added to the reaction mixture at a temperature of 15 to 60°C, 11- Method as>m specified in claim 7, characterized in that during step b) the reaction mixture is heated at reflux temperature. 12, Method as stated in claim 1, characterized in that the catalyst is formic acid, 13. Method as stated in claim 1 characterized in that the catalyst is ammonium formate, .14, Method as stated in claim 1, characterized in that the catalyst is ethya£ormate. 15. Method as stated in claim 1, characterized in that the manganese oxide is brought into contact iried. 3.5. t 5~ trimethylhexanoic acid in the presence of a formic acid catalyst, 16. Method as stated in claim 1, characterized in that the manganese oxide is brought into contact with 2-ethylhexanoic acid in the presence of a formic acid catalyst. 17. Method as stated in claim 1, characterized in that manganese oxide is brought into contact with naphthenic acid in the presence of a formic acid catalyst. 18. Method as stated in claim 1, characterized in that the manganese oxide is brought into contact with a mixture of 3,5,5-trimethylhexanoic acid and 2^ ethylhexanoic acid in the presence of a formic acid catalyst. 19. Method © m specified in claim 5, characterized in that the amount of water present is between 10 and 80% of the weight of manganese in the manganese oxide. 20. Method as stated in claim 5, characterized in that the organic solvent which is not miscible with water is a hydrocarbon fraction and petroleum oil.