DK159307B - Ethoxyquin salts with alkanoic acids, solutions of the ethoxyquin salts, and the use thereof - Google Patents

Description

DK 159307 B

The present invention relates to novel salts of ethoxyquin.

Ethoxyquin (6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline) is widely used as an antioxidant, especially for bulk materials such as fishmeal or grass meal, to avoid on one hand oxidation degradation such as rancidity and on the other side to avoid explosions. Ethoxyquin is usually applied at concentrations in the range of 100-500 ppm.

However, there are several disadvantages to ethoxyquin. First, pure ethoxyquin is a viscous oil at normal temperatures (about 2000 cps at 20 ° C), and viscosity is rapidly increased with decreasing temperature (about 6000-7000 cps at 10 ° C). Furthermore, the viscosity of technical grades of ethoxyquin, which may range from 90% ethoxyquin to down to 50-60% or even less, is significantly increased with increasing content of impurities, and at the same time the viscosity of a given ethoxyquin product will also increase when not protected. of an inert atmosphere such as N 2. The increase in viscosity is due to a polymerization reaction, which in turn is caused by the presence of oxygen and accelerated by the influence of light. The high viscosity makes it very difficult to distribute ethoxyquin evenly in quantities as low as the above 100-500 ppm in bulk materials such as fishmeal. There will be a tendency for the presence of local, high concentrations of ethoxyquin in the bulk material, leading to poor oxidation protection in other parts of the material. Second, ethoxyquin is only soluble in water at very low concentrations, making it impractical to try to distribute ethoxyquin in a bulk product as an aqueous solution.

In order to overcome the aforementioned problems, it has been previously attempted to use ethoxyquin absorbed in silica gel or as an emulsifier stabilized suspension (stabilized with Tween®80 or other emulsifiers) to obtain a form of ethoxyquin that is more easily dispensable.

However, even such forms have the disadvantages associated with the general storage properties of ethoxyquin. As mentioned above, both oxygen and the influence of light tend to degrade ethoxyquin.

DK 159307 B

2 In a further attempt to overcome the problems surrounding ethoxyquin, certain salts have been previously prepared, namely the hydrochloride, the sulfate, the phosphate and the succinate. Unfortunately, such salts, which in themselves are crystalline, are not very soluble in water, the solubility of, for example, the hydrochloride being only approx. 5% by weight.

Ethoxyquin also finds use as a protective agent against apple scab, the apples being dipped in an emulsifier-stabilized solution of ethoxyquin in water, and the concentration of ethoxyquin of the order of 2 ppm. The preparation of such a immersion mixture is somewhat complicated and involves admixing a mixture of ethoxyquin and emulsifier (e.g. Tween®80) in a solution of the same emulsifier in water.

The invention relates to a salt of ethoxyquin having an alkanoic acid containing 15 to 5 carbon atoms.

Examples of alkanoic acids having 1-5 carbon atoms include formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid and valeric acid.

Among these acids, formic acid is preferred.

In the present invention, the disadvantages of the above-described ethoxyquine formerly described above are substantially avoided or reduced, both in viscosity, water solubility and / or increasing viscosity due to oxidation-induced polymerization.

Thus, the salts of the invention are characterized by solubility in or miscibility with water and / or in that they themselves are liquids.

For example, ethoxyquinformiat is soluble in water and is itself a liquid, even at -18 ° C.

Furthermore, the salts of the invention which are liquids do not undergo any significant increase in viscosity when exposed to the influence of oxygen and light. This is believed to be due to the formation of ethoxyquin ions inhibiting the rearrangement and radical reactions that form part of the polymerization process. The salts 3

DK 159307 B

according to the invention exhibit longer shelf life than ethoxyquin when exposed to oxygen and light.

Even if the viscosity of the salts of the invention were to be too high for certain applications, adding small amounts of water to the salt, such as amounts between 0.1 and 20% by weight, can substantially reduce the viscosity and thereby enable adaptation to the particular application without significantly increase the amount of ethoxyquin salt needed for the particular purpose.

The salts of the invention are also well soluble in / miscible with 10 lower alkanoic acids. This is surprising, especially in view of the low solubility of other ethoxyquin salts in aqueous media, for example the low solubility of ethoxyquin hydrochloride in water described above. The invention therefore also relates to a solution of an ethoxyquin salt of an alkanoic acid containing 1-5 carbon atoms in an alkanoic acid containing 15-5 carbon atoms or in a mixture of such alkanoic acids, the weight ratio of ethoxyquin base to the alkanoic acid or mixture thereof being from 1: 100 to 5 : 1, especially from 1:10 to 5: 1.

The advantage of the above-described solutions of ethoxyquin salts in lower alkanoic acids is that such acids, for example formic acid, propionic acid and isobutyric acid, are also used as silicating agents, and the solutions of the ethoxyquin salts of the lower alkanoic acids thus provide an easily distributable combination of silicating agent and antioxidant for the preparation. of silage.

Salts of ethoxyquin with an alkanoic acid containing 1 to 5 carbon atoms can be prepared by a process comprising mixing ethoxyquin with the alkanoic acid, the ethoxyquin being optionally dissolved in a solvent such as an aliphatic hydrocarbon, an aromatic hydrocarbon or a halogenated hydrocarbon. It is preferred that the acid used is formic acid.

Examples of aliphatic hydrocarbon solvents include pentane, hexane, heptane, octane or nonane, or mixtures thereof such as mixtures defined by boiling intervals, namely petroleum ethers at boiling intervals such as 40-60 ° C.

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4 60-80 ° C, 80-100 ° C, 100-120 ° C or the like. Examples of aromatic hydrocarbons include benzene or aliphatic substituted benzene such as toluene or xylene, or other substituted benzenes such as nitrobenzenes. Halogenated hydrocarbons may include both halogenated aliphatic hydrocarbons such as methylene chloride, chloroform, carbon tetrachloride, trichlorethylene, or perchlorethylene, or halogenated aromatic hydrocarbons such as chlorobenzene, dichlorobenzene or the like.

The mixture of ethoxyquin and alkanoic acid, whether or not the ethoxyquin is dissolved in a solvent of the type described above, can be carried out within a wide temperature range such as between 0 ° C and 100 ° C, for example at room temperature.

The present invention also relates to the use of a salt of ethoxyquin with an alkanoic acid containing from 1 to 5 carbon atoms as an antioxidant or as an antifungal scouring agent. The invention further relates to the same uses of a solution of a salt in an alkanoic acid containing from 1 to 5 carbon atoms or in a mixture of such alkanoic acids.

In the application described above, the alkanoic acid salt of ethoxyquin or the solution thereof in an alkanoic acid can be used in aqueous solutions at concentrations ranging from 0.1 ppm to 10%, especially from 0.5 ppm to 1%, especially 1-100 ppm such as 1-10 ppm calculated from ethoxyquin salt.

Experiments have been described in the literature (Preben Møller Jensen, Gunnar Jørgensen (Dan-25 mark) Beret. Statens Livdyrbrugsfors. 1975, 427. p. 79) where herring silage for mink feed was treated with a mixture of formic acid and ethoxyquin. There is no indication in the article that this treatment causes the formation of ethoxyquinformiate in the silage, and it is further clear that the problems of using ethoxyquin itself, ie. high viscosity and low solubility in water are still relevant in this regard.

The invention is further illustrated by the following examples.

5

DK 159307 B

EXAMPLE 1 Ethoxyquinformiat

The formate of ethoxyquin was prepared by mixing equimolar amounts of ethoxyquin (100 g, purity approximately 99.9%) and formic acid (21.1 g, purity 99-100%) in a flask with stirring at room temperature. The resulting salt was liquid and could not be crystallized even after cooling to -18 ° C. The salt was soluble in water at a pH below 3, in formic acid, acetic acid and propionic acid, as well as in isopropanol, acetone and ethyl acetate. The salt, unlike 10 ethoxyquin itself, was insoluble in petroleum ether, chloroform and carbon tetrachloride.

The pure ethoxyquinformiat, ethoxyquinformiat with 3 wt% water added and with 15% water added had viscosities of 600 cps, 330 cps and 80 cps, respectively, measured at 20 ° C on a Brookfield LVT viscometer. Furthermore, ethoxyquinformiat with 15% by weight of water added had a viscosity of 100 cps at 5 ° C and 280 cps at ca. 0 ° C.

EXAMPLE 2

Ethoxyquin acetate dissolved in acetic acid 100 g of ethoxyquine and 153.4 g of glacial acetic acid were mixed with stirring 20 at room temperature. A 50% by weight solution of ethoxyquin acetate in glacial acetic acid was thus obtained. The solution had a viscosity of 60 cps at 20 ° C.

Claims (4)

An salt of ethoxyquin characterized in that it is the ethoxyquin salt with an alkanoic acid containing from 1 to 5 carbon atoms. Salt according to claim 1, characterized in that the alkanoic acid is formic acid. A solution of a salt according to claim 1 or 2, characterized in that the salt is dissolved in an alkanoic acid containing from 1 to 5 carbon atoms or in a mixture of such alkanoic acids, the weight ratio of ethoxyquin to the alkanoic acid or the mixture thereof being from 1: 100 to 5: 1, especially from 1:10 to 5: 1. Use of a salt of ethoxyquin according to claim 1 or 2 or a solution according to claim 3 as an antioxidant or as an agent for 20 fruit pods.