MX2008007959A - Production of acid propionates - Google Patents

Abstract

The invention relates to compositions containing propionic acid in a solid and essentially pure form, said compositions also containing at least one compound of formula (I) (Mn+)(H+)x(CH3CH2C(O)O-)(n+x), wherein Mn+represents an n-valency alkali metal or alkaline earth metal cation, n being equal to 1 or 2, and x represents a number between 0.25 and 5, with the proviso that x does not represent a number between 0.75 and 1.75 when Mn+represents potassium. The invention also relates to a method for producing such compositions containing propionic acid, and to the use of such compositions as ensilage auxiliary agents, conservation agents, acidifiers, food supplements, animal feed, or animal feed additives.

Description

PRODUCTION OF ACID PROPIONATES The present invention relates to alkali metal comprising propionic acid and alkaline earth metal salts in solid form, methods for their production, their use as additives, preservatives, acidifier, food supplements, food products or food additives for animal feeds. The alkali metal comprising propionic acid and alkaline earth metal salts and media (usually liquid) comprising the same have an antifungal activity and can serve, for example, for the preservation and acidification of plant and animal material, for example grasses, products agricultural or meat, also as an additive for human or animal nutrition. In particular, they are suitable as silage additives or silage aids in the production of silage, since the reduction in pH caused by them counteracts an emergence of putrefactive bacteria. The propionic acid present in these salts can accelerate the fermentation of lactic acid and prevent secondary fermentation. With few exceptions, these salts, also called acid propionates, have previously been described and used or proposed to be used in dissolved form. This is due in particular to the fact that the solid forms of these compounds, such as salts of acid metals of carboxylic acids of low molecular weight in general, are considered very unstable, which sometimes make their production relatively complex (cf. .gr., EP 0 032 807 To page 1, lines 3-1). The adequate stability of these compounds, however, is of particular importance with respect to handling, storage capacity and production. In particular, the relatively large or uncontrolled release of the propionic acid present in the compounds, which belong to this corrosive action, and due to its unpleasant odor, is inconvenient. DE 26 53 449 A1 and DE 27 22 919 A1 disclose both, inter alia, alkali metal dipropionates of acid and also tetrapropionates of alkaline earth metals in dissolved form. In US 4,401,624, the regulated solutions comprising, e.g., sodium dipropionate, are described as having reduced corrosivity compared to free propionic acid. EP 0 112 080 A1 describes the use of solid potassium acid propionate (potassium dipropionate) as a preservative for animal feed, but without specifying its production. According to DE 24 32 473 A1, among others, solid potassium acid propionate (potassium dipropionate) is such that it can be produced by the fluidized bed method described herein. The production of said solid potassium acid propionate (potassium dipropionate) from aqueous or alcoholic solution of propionic acid and neutral potassium propionate by evaporation, filtration and washing with ethanol is described by Levi TG, Gazette Chimica Italiana 1932, 62, 709- 716 This publication states that additional potassium acid propionates, such as for example potassium acid tripropionate, can not exist, or are not accessible by the process described herein. EP 0 123 416 A1 and EP 0 032 807 Al also discloses potassium acid propionate (potassium dipropionate) in solid form which was obtained by crystallization of an aqueous solution of propionic acid and neutral potassium propionate. In EP 0 032 807 Al, however, potassium dipropionate is only a by-product, since the method described therein is mainly directed to the production of solid dipotassium pentapropionate. While the method according to EP 0 123 416 Al has to start from an equimolar solution of the aforementioned starting materials, in the method according to EP 0 032 807 Al, the molar ratio of these starting materials may vary. However, explicit statements in this regard can not be taken from EP 0 032 807 Al; in the examples, the equimolar mixtures or a one and a half times excess of propionic acid is used. In the latter case, however, the resulting solid is a mixture of potassium dipropionate and dipotassium pentapropionate. US 3,008,986 describes the production of solid acid sodium propionate which, as an unwanted by-product, comprises traces of sodium dipropionate on the scale of a few hundred ppm. In the field of animal nutrition, acid propionates offer, in particular, the advantage that the desired cations can be combined with a favorable nutritional value via these compounds. Especially acid propionates comprising sodium offer the advantage that the sodium of the trace elements does not need to be added separately as is otherwise common in the NaCl form, but is already present as a source of sodium. Via a defined propionic acid content in acid propionates comprising sodium, the content of sodium ions could further be controlled or restricted. A small or restricted content of cations, e.g., also of potassium ions is convenient to the extent that the latter, particularly in the case of monogastric animals, and especially in the case of birds, leads to an increased consumption of liquids ( increased drink) and therefore to the dilution of the feces of the animals, and consequently can exhibit a diuretic action.

It is therefore an object of the present invention to provide compounds as stable as possible in solid form, in particular in crystalline and / or dry form, which essentially comprises propionic acid and propionates of alkali metals or alkaline earth metals and also methods for their production . These production methods should allow the controlled particular establishment of the content and especially the establishment of a high content of propionic acid in the target compounds. In addition, production methods should be able to be used efficiently in the context of industrial production. For this reason, the compounds of the invention should also be distinguished, in particular, by the simple handling and especially by a comparatively low vapor pressure. This object has surprisingly been achieved by obtaining the target compounds from a defined homogeneous mixture of propionic acid and the respective neutral alkali metal propionate or alkaline earth metal propionate, the mixture being virtually anhydrous or at least having only very little water content. The present invention therefore relates to a method (A) for producing a composition comprising propionic acid in solid and essentially pure form, comprising at least one compound according to formula (I) (Mn +) (H +) x (CH3CH2C (0) 0-) (n + x) (I), wherein Mn + is an alkali metal cation with valence non-cation of alkaline earth metal, e.g., lithium, sodium, potassium, rubidium, cesium, beryllium , magnesium, calcium, strontium or barium; preferably sodium, potassium, magnesium or calcium; and particularly preferably sodium or calcium; n being equal to 1 or 2; and x is a number on the scale of 0.25 to 5; preferably on the scale of 0.3 to 2.5; wherein a homogeneous mixture is produced from the neutral alkali metal propionate or alkaline earth metal propionate and propionic acid in a molar ratio in the range of 1: 0.25 to 1.5; preferably in the scale from 1: 0.3 to 1: 3.5; and particularly preferably in the scale from 1: 0.3 to 1: 2.5, with heating and the homogenous mixture solidifying, and the water content of the homogeneous mixture, at least at the beginning of solidification, and in particular also during the mime , being less than 1% by weight, based on the total passage of the mixture. The neutral alkali metal propionate and alkaline earth metal propionate mean in the present and then those which have no proton content. Preferably, use is made of the neutral propionates of the following metals: lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium or barium; particularly preferably sodium, potassium, magnesium or calcium; and very particularly preferably sodium or calcium. Such neutral propionate and methods for its production are known to those skilled in the art; some of these compounds are also commercially available, v.gr, sodium propionate (E281), potassium propionate (E283) and calcium propionate (E282). A customary process for the production of the neutral propionates that will be used is, eg, to react the alkali metal hydroxide or the respective alkaline earth metal, carbonate or hydrogen carbonate with propionic acid, in this variant, then a process is followed , e.g., such as the alkali metal hydroxide or solid alkaline earth metal hydroxide or a concentrated aqueous solution thereof, was dissolved, if appropriate with cooling and / or stirring, in preferably concentrated propionic acid. This mixture, if appropriate, is then brought to neutralization of the excess acid, to crystallization, e.g., decreasing the content of water or acid to the mixture, which proceeds by means of the common methods known to those skilled in the art. the material, e.g., evaporation, extraction, distillation and the like. The neutral crystallized propionate of alkali metals or alkaline earth metals is then isolated by methods known to those skilled in the art to separate solid and liquid phases. Usually, a neutral propionate is used which comprises not more than 0.5% by weight, based on the total weight of the neutral propionate source used, of foreign constituents other than water. Preferably, use is made of a source of neutral propionate comprising less than 0.1% by weight, and in particular less than 0.05% by weight, in each case based on the total weight of the neutral propionate source used, of ions of potassium. Commonly, to produce the homogeneous mixture, use is made of a concentrated propionic acid having a propionic acid content of at least 95% by weight and in particular at least 99% by weight, based on the total weight. The homogeneous mixture of the starting materials can be produced by normal procedures known to those skilled in the art, eg, by mixing, stirring or dissolving by the use of elevated temperatures, e.g., above 30 ° C, or for a combined use of these methods. The sequence of use of the starting materials is of minor importance. Advantageously, the starting materials are combined in such a way that a homogeneous liquid mixture of the starting materials is obtained in the desired molar ratio. If, after the combination, all the components are not completely present in dissolved form, the temperature is raised, preferably with stirring, until the desired melting or solution is obtained. During the combination of the starting materials the reaction mixture is stirred advantageously, e.g., stirred vigorously. Agitation continues until after the combination is completed at least until the melt or solution is obtained, in the latter case, commonly until the crystallization is complete or finished. According to the invention, the starting materials can be mixed in all commonly used apparatuses to produce a homogeneous liquid mixture, such as reactors, vessels, flasks, etc., in particular in stirred tanks, especially those having exchange surfaces. internal heat. These are known to those skilled in the art. To avoid the effects of corrosion, e.g., in reactors and vessels made of steel, it is advantageous when the surfaces and walls that come in contact with propionic acid and coated with an acid-resistant protective layer, e.g. of Teflon®, or are specially aligned with steels of highly acid-resistant alloys. According to the invention, the homogeneous mixture was produced with heating. This means temperatures of at least 30 ° C, in particular at least 40 ° C and especially at least 50 ° C, generally 250 ° C, and in particle 200 ° C, not being exceeded. The temperature required to achieve a homogeneous mixture will depend on the individual chaos in the type of metal cation used and also on the molar ratio of starting materials used. It is essential for the invention in the production method (A) that the heating generates a completely homogeneous mixture. This homogeneous mixture can be a melt or a solution. To carry out the method (A) according to the invention, a process is generally followed so that the starting materials are combined at room temperature. The combination can be simultaneous or sequential and independently of each other in each case in the portions, eg, in 1, 2, 3, 4 or more, in particular from 2 to 20, and especially from 3 to 10 portions, or continuously, that is, to a constant, decreasing or increasing regime. Subsequently, the reaction mixture is heated until the homogeneous mixture is obtained in the form of a melt or solution. The continuous addition of one or both starting materials can also proceed in such a way that the starting materials brought to, and maintained at, room temperature, are added to the already heated reaction mixture. Commonly, the temperature of the mixture is adjusted in such a manner, e.g., by equalizing the rate of addition and / or cooling or heating of the mixture and / or of the aggregate starting materials., so that the mixture is maintained at a temperature on the scale of 30 ° C to 200 ° C and in particular on the scale of 40 ° C to 180 ° C. According to the invention, the homogeneous mixture obtained in this way at least partially solidifies. Depending on whether or not the homogeneous mixture is present in the form of a melt or solution, the solidification step may vary. In the present solidification it means that the mixture, in the case of a melt, is brought to settling (variant Al), or in the case of a solution, is brought to crystallization (variant A2). In the first case (Al), the entire homogenous mixture is commonly brought to settlement, if a small amount of residual moisture is appropriate, in particular propionic acid, being present in the settlement product, e.g., less than 1% by weight, in particular less than 0.5% by weight, based on the total weight of the product (ie, the resulting solid composition).

Preferably, the settlement product does not comprise fractions of residual moisture. In the latter case (A2), generally a solid phase is crystallized from the liquid mixture, a part of the liquid phase being obtained as the mother liquor. The solidification is preferably caused by the cooling of the mixture, e.g., at a temperature of less than 30 ° C and in particular at room temperature and / or by evaporation of volatile constituents of the mixture, in particular water or propionic acid , if appropriate under vacuum. In the case of variant A2, the cooling or evaporation may proceed in the presence of seed crystals of the respective desired compound of the formula (I). When the reaction mixture, in cooling or evaporation, in addition to a solid phase comprising the compound of the formula (I), also forms a liquid phase (provided that the acidification proceeds according to the variant Al or A2), it depends on the individual case of the type of metal cation used and also of the molar ratio of the starting materials used or in the stoichiometry of the resulting compound of the formula (I). This can be determined in a simple manner in the individual chaos by those skilled in the art reproducing the production route described herein. If the heating of the homogeneous mixture leads to a melt (variant Al), this generally leads to settling by cooling, in this case commonly a single solid phase is obtained which essentially comprises at least one, e.g., 1 or 2, compounds of the formula (I). An advantage of this variant of the method according to the invention, in particular, is that without using a drying step, a dry product is obtained, e.g., having a residual moisture content of the water and / or propionic acid of almost 1% by weight, based on the total weight of the product. By means of a drying step, as described above, this residual moisture content can be further reduced. If the heating of the homogeneous mixture leads to a solution (variant A2), this is preferably carried out by crystallization by cooling. In this case commonly a solid phase is obtained which essentially comprises one, e.g., 1 or 2 and in particular 1, compound of the formula (I) and a liquid phase (mother liquor). After crystallization, the resulting solid product is separated from the mother liquor. The solid phase can be separated from the mother liquor by common methods known to those skilled in the art for this, e.g., filtration or centrifugation, preferably via centrifugation, in particular using discharge or knife discharge centrifuges. The product thus obtained generally comprises small amounts of propionic acid, water and / or neutral propionate used, which can be reduced by a subsequent stripping step, as described below. If settling occurs (variant (Al)), this is generally brought to settle by cooling. In this case commonly a single solid phase is obtained which essentially comprises at least one, e.g., 1 or 2, compounds of the formula (I). An advantage of this variant of the method according to the invention, in particular, is that without using a drying step, a drying product is obtained, e.g., having a residual moisture content of water and / or acid. propionic of almost 1% by weight, based on the total weight of the product. By means of a drying step, as described above, this residual moisture content can be further reduced. If the heating of the homogeneous mixture leads to a solution (variant A2), it is preferably brought to crystallization by cooling. In this case, a solid phase is commonly obtained which essentially comprises one, e.g., 1 or 2, and in particular 1 compound of the formula (I) and a liquid phase (mother liquor). After crystallization, the resulting solid product is separated from the mother liquor. The solid phase can be separated from the mother liquor by common methods known to those skilled in the art for this., eg, filtration, or centrifugation, preferably via centrifugation, in particular, using impeller or knife discharge centrifuges. Therefore the product so obtained generally still comprises small amounts of propionic acid, water and / or neutral propionate used, which can be reduced by a subsequent drying step, as described above. If the settlement (variant (Al)) is carried out by cooling, it generally proceeds in the course of a few minutes. In the crystallization (variant (A2)) is carried out by cooling, this preferably proceeds slowly, advantageously over a period of one or more hours, eg, on a scale of 1 to 48 hours, in particular 2 hours. 24 h, and especially from 4 to 12 hours, in this chaos, the white compound crystallizes. The cooling may proceed, e.g., at a cooling rate in the range from about 1 to about 25 k / h, e.g., from about 2 to about 20 k / h. To achieve through the crystallization of the white compound, it is advantageous to cool the reaction mixture in said period to a temperature of less than 30 ° C, e.g., at room temperature or less. Generally, in this chaos the temperature does not fall below 0 ° C and in particular 5 ° C. If, in the chaos of the variant (A2), a solution is brought to crystallization by cooling, it may be advantageous, after the start of crystal formation, to redissolve the seeds of crystals or small crystals formed first by repeated temperature rise , e.g., by 5 to 10 ° C, or if it is necessarily more, and to restart the crystallization process subsequently by repeated cooling, if appropriate with reduced speed. In addition, in the case of the variant (A2) it may be advantageous to add to the pre-existing solution, eg, produced in advance by the method according to the invention, the crystals of the desired compound of the formula (I) to promote the crystallization process, that is, in order to be called "seedbed". Such crystals can be added in dry or wet form, e.g., suspensions in a liquid, preferably a propionic acid phase, or a combination of these forms. In this case, the addition generally, but does not necessarily proceed above a temperature that leads to spontaneous crystal formation and in any case below a temperature at which aggregated seed crystals dissolve. The temperatures of the reaction mixture suitable in each case can be determined by those skilled in the art without problems in routine experiments. The crystallization process can continue as described above. The product which, in particular in the case of variant (A2) is still wet, can be dried by common drying methods, e.g., under vacuum and / or moderate heating. The dryers and drying methods that can be used for this are known to those skilled in the art and are described in K. Króll, Trockner und Trocknungsverfahren [Dryers and drying methods], 2a. Edition, Springer Verlag, Berlin 1978. In particular, you can make use of eg contact dryers, fluidized bed dryers and radiant colored dryers. It is also possible to use spray dryers, advantageously the crystallization steps and the parallel drying process. Upon drying, the relatively high volatility of the propionic acid present in the product and also if a limited temperature stability of the product is appropriate, should be taken into account. During drying, commonly in the case of acid alkali metal propionates, the product temperatures will not exceed 75 ° C, and in particular 50 ° C, and in the chaos of acid alkaline earth metal propionates, the product temperatures will not they will exceed 150 ° C. The water content that remains in the product or in the resulting composition (residual water content) in the variant (Al) after settling and to a drying step, or in the chaos of (A2) after a drying step, is generally about 1% by weight, preferably about 0.5% by weight, and commonly on the scale of about 0.5 to 0.01% by weight, based on the total weight of the composition. If (Al), the water content is particularly preferably the greater part of 0.3% by weight, very particularly preferably almost 0.2% by weight and frequently in the range of 0.25 to 0.01% by weight, based on the total weight of the composition . In this case the water content is determined in each case by oxidimetric titration according to Kart Fischer (e.g., described in Wiland, asserbestimmung durch Kart-Fischer-Titration [Water Determination by Kart-Fixher titration], Darmstadt , GIT, 1985). In the present and thereafter, the total weight of the expression of the composition is used synonymously with the expression of total dry weight. The total dry weight should be understood to be the weight of the composition that is obtained by drying the product below its decomposition temperature, eg, in the case of alkali metal acid propionates, drying for a period of 1 hour. has a temperature of 40 ° C and a pressure of 50 mbar, or in the case of alkaline earth metal propionates, for a period of 1 h at a temperature of 100 ° C and a pressure on the scale from 1 bar to 50 mbar, in particular 50 mbar. In the method (Al) according to the invention, M1 + is preferably an alkali metal, particularly preferably sodium or potassium, and very particularly preferably sodium. In the method (Al) according to the invention, the molar ratio of neutral alkali metal propionate to propionic acid in the homogeneous mixture preferably is in the range of 1: 0.4 to 1, and particularly preferably in the scale of 1: 0.5 to 1: 2.5; v.gr., approximately 1: 1 or 1: 2 In the method (Al) according to the invention, in particular the compounds of the formula (I) are obtained in which x is on the scale of 0.4 to 3, and especially on the scale of 0.5 to 2.5; e.g., about 1 or 2. In a particularly preferred embodiment of the method (Al) according to the invention, M1 + is sodium and the molar ratio of neutral sodium propionate to propionic acid in the homogeneous mixture is on the scale of 1: 0.4 to 1: 3, and particularly preferably in the scale of 1: 0.5 to 1: 2.5; e.g., approximately 1: 1 or 1: 2. The acid sodium propionate obtained in this modality exhibits, in differential scanning calorimetry (DSC), a phase transition point, depending on its composition, in particular at a temperature of 61 ° C and if it is appropriate at 90 ° C. In addition, the powder X-ray diffractogram of these acid sodium propionates is characterized, in particular, by diffraction peaks at least 4, in particular at least 5, and especially at least 7, selected frame separations. of d = 13.63; 13.13; 13.03; 11.09; 9.71; 9.59; 3.94; 2.84; 2.79 [Á] (± 0.04 [Á]). Additional diffraction peaks are often observed in the following frame separations: d = 4.88, 4.14, 3.68; 3.46; 3.26; 3.09; and / or 2.96 [Á] (± 0.04 [A]). It is obvious to those skilled in the art that very close frame separations can be placed on top of each other in the powder X-ray diffractogram. This, in particular, can occur in the reflection positions of d = 13.13 and 13.03 [Á] and d = 9.71 and 9.59 [Á] m so that in each case only one reflection is observed in this frame separation. The normal relative intensities obtained in this modality for x = 2 (see example 1 below) and x = 1 (see example 3 below) in the powder X-ray diffractogram are listed in table 1.

Table 1 In the method (A2) according to the invention, M1 + is preferably an alkaline earth metal, particularly preferably calcium or magnesium and very particularly preferably calcium. In the method (A2) according to the invention, the molar ratio of the neutral alkali metal propionate to propionic acid in the homogeneous mixture preferably is in the range of 1: 0.5 to 1:10, particularly preferably in the scale of 1. : 1 to 1: 8, and very particularly preferably on the scale of 1: 2 with 1: 5, e.g., approximately 1: 3. In the method (A2) according to the invention, the particular compounds of the formula (I) are obtained in which x is on the scale of 0.25 to 0.6, and especially on the scale of 0.3 to 0.5, v.gr. , approximately n? .4. In a particularly preferred embodiment of the method (A2) according to the invention, Mn + is calcium and the molar ratio of neutral calcium propionate to propionic acid in the homogeneous mixture is in the range of 1: 1 to 1: 8, and particularly preferably on a scale from 1: 2 to 1: 5, e.g., approximately 1: 3. The acidic calcium propionates obtained in this embodiment exhibit a transition point of asees in the differential scanning calorimetry in particular at a temperature in the range of 167 to 168 ° C. In addition, the powder X-ray diffractogram of these acid calcium propionates is characterized, in particular, by diffraction peaks in at least 5, in particular at least 7, especially at least 9, and most especially all the selected frame separations of d = 12.70; 9.42; 8.91; 8.16; 6.65; 6.38; 4.51; 4.26; 4.03; 3.81 [Á] (± 0.04 [Á]). The additional diffraction peaks are often observed in this case in the following frame separations: d = 24.86; 3.93; 3.32; 2.83 and / or 2.56 [Á] (± 0.04 [A]). The normal relative intensities obtained in this modality for x = 0.4 (see example 4 below) in the powder X-ray diffractogram are listed in Table 2.

The method (A) according to the invention can be carried out continuously, semicontinuously or in batches. It is particularly advantageous in the variant (Al) that a dry product can be obtained without the use of a drying step and that the stoichiometry of the resulting compound of the formula (I) can be freely adjusted on a wide scale via the selection of the ratio molar of the starting materials in the homogeneous mixture produced. Generally, compositions comprising compounds of the formula (I) can be produced in this manner having a propionic acid content in the range of 5 to 70% by weight, and in particular in the range of 10 to 65% by weight, based on the total weight of the composition.

The present invention further relates to a method (B) for producing a composition comprising propionic acid in essentially pure and solid form, comprising at least one compound according to formula (I) (Mn +) (H +) x ( CH3CH2C (0) CT) (n + x) (I), wherein Mn + is an alkali metal cation with valence non-cation of alkaline earth metal, e.g., lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium , calcium, strontium or barium; preferably sodium, potassium, magnesium or calcium; and particularly preferably sodium or calcium; n being equal to 1 or 2; and x is a number on the scale of 0.25 to 5; preferably on the scale of 0.3 to 2.5; wherein a homogeneous mixture is produced from the neutral alkali metal propionate or alkaline earth metal propionate and propionic acid in a molar ratio in the range of 1: 0.25 to 1.5; preferably in the scale from 1: 0.3 to 1: 3.5; and particularly preferably in the scale from 1: 0.3 to 1: 2.5, with heating and the homogenous mixture solidifying, the water content of the homogeneous mixture, at least at the beginning of solidification, and in particular also during the mime, being less than 1% by weight, based on the total weight of the mixture; and the molar ratio of neutral alkali metal propionate and alkaline earth metal propionate to propionic acid in the homogeneous mixture not being in the range of 1: 0.75 to 1: 1.75, when Mn + is potassium. With respect to the neutral alkaline earth metal (alkaline earth) propionates useful in this variant (B), the statements made above on the method (A) according to the invention apply. In variant (B), to produce the homogeneous mixture, one can make use not only of concentrated propionic acid, as in variant (A), but also an aqueous solution thereof. In the latter chaos, the aqueous propionic acid solution used preferably has a concentration of at least 95% by weight, more preferably at least 98% by weight. Particularly preferably, use is made of concentrated propionic acid having a propionic acid content of at least 99% by weight. The concentration of propionic acid or propionic acid solution preferably in the range of 95 to 99% by weight. If the alkali metal propionates (neutral alkaline earths to be used are produced by the reaction with propionic acid in aqueous solution, as explained above for method (A), in this case the molar ratios of the starting materials can be advantageously selected directly so that the components of protonic acid, neutral alkali metal (alkaline earth) propionate and water in the reaction batch resulting already in the required molar ratios mentioned above In variant (b), the mother liquor of crystallization can also be used in the production of The homogenous mixture The homogeneous mixture can be produced by combining the starting materials and heating the reaction mixture in the same manner as described above for variant (A). It is essential for the invention, in the present, in particular that the crystallization comes from an aqueous solution.This can, as established for (A2), have been mixed with the seed crystals to before the start of crystallization. The aqueous solution, preferably with continuous stirring, are brought to crystallization, e.g., by partial evaporation or by cooling, preferably by cooling. If crystallization is caused or induced or accelerated by controlled evaporation of the liquid phase, preferably under vacuum, it is necessary to ensure that the molar ratios of the components in the solution lie within the scales specified before the start of crystallization.

After crystallization of the solid product, as described above for (A2), they are separated from the mother liquor and preferably subjected to a drying step, as described above for (A2). This produces compositions comprising compounds of the formula (I) having dry contents as described above for (Al) or (A2). Compounds comprising compounds of the formula (I) which have a propionic acid content in the range of 5 to 70% by weight, and in particular in the range of 10 to 65% by weight, based on the weight can be produced total of the composition. In a preferred embodiment of the method (B) according to the invention, Mn + is an alkali metal, particularly preferably sodium or potassium and very particularly preferably sodium. In the method (B) according to the invention, the molar ratio of neutral alkali metal propionate to protonic acid in the homogeneous mixture preferably ranges from 1: 8 to 1: 2.2, and particularly preferably in the scale of 1: 1.9 to 1: 2.1; e.g., approximately 1: 2. In this variant (B), in particular the compounds of the formula (I) are obtained, in which x is on the scale of 1.8 to 2.2, and especially on the scale of 2.1 to 2.2, e.g., of about 2. .

In a particularly preferred embodiment of the method (B) according to the invention, Mn + is sodium and the molar ratio of neutral sodium propionate to propionic acid in the homogeneous mixture is in the range of 1: 1.8 to 1: 2.2 and particularly of preference in the scale from 1: 1.9 to 1: 2.1, eg, approximately 1: 2. The acid sodium propionates obtained in this modality exhibit, in differential scanning calorimetry (DSC, for its acronym in English), a particular phase transition point at a temperature of 61 ° C. In addition, the powder X-ray diffractogram of these acid sodium propionates is characterized in particular by the diffraction peaks by at least 4, in particular at least 5, and especially at least 7, selected frame separations of d = 13.63, 13.13; 13.03; 11.09; 9.71; 9.59; 3.94; 2.84; 2.79 [A] (± 0.04 [A]). The additional diffraction peaks are often observed in this case in the following frame separations: d = 4.88; 4.14; 3.68; 3.46; 3.09; and / or 2.96 [A] (± 0.04 [A]). The normal relative intensities obtained in this case for x = 2 (see example 5 below) in the powder X-ray diffractogram are listed in Table 3.

Table 3 In a further preferred embodiment of the method (B) according to the invention, Mn + is an alkaline earth metal, particularly preferably calcium or magnesium and very particularly preferably calcium. In the method (B) according to the invention, the molar ratio of the neutral alkaline earth metal propionate to propionic acid in the homogeneous mixture is preferably in the range of 1: 0.5 to 1:10, particularly preferably in the scale of 1. : 1 to 1: 8, and very particularly preferably in the scale of 1: 2 to 1: 5, eg, approximately 1: 3. In this variant (B), compounds of the formula (I) are obtained in particular in which x is on the scale of 0.25 to 0.6, and especially on the scale of 0.3 to 0. 5, e.g., approximately 0.4. In a particularly preferred embodiment of the method (B) according to the invention, Mn + is sodium and the molar ratio of neutral sodium propionate to propionic acid in the homogeneous mixture is in the range of 1: 1.8 to 1: 2.2 and particularly of preference in the scale from 1: 1.9 to 1: 2.1, eg, approximately 1: 2. The acid sodium propionates obtained in this modality exhibit, in differential scanning calorimetry (DSC, for its acronym in English), a particular phase transition point at a temperature of 61 ° C. In addition, the powder X-ray diffractogram of these acid sodium propionates is characterized in particular by the diffraction peaks by at least 4, in particular at least 5, and especially at least 7, selected frame separations of d = 13.63, 13.13; 13.03; 11.09; 9.71; 9.59; 3.94; 2.84; 2.79 [A] (± 0.04 [A]). The additional diffraction peaks are often observed in this case in the following frame separations: d = 4.88; 4.14; 3.68; 3.46; 3.09; and / or 2.96 [A] (± 0.04 [A]). The normal relative intensities obtained in this case for x = 0.4 (see example 6 and example 7 below) in the powder X-ray diffractogram correspond to the relative intensities listed in the following table 2 for the respective reflection positions. The method according to the invention (B) can be carried out continuously, semicontinuously or in the form of batches. Generally, the compounds of the formula (I) can be produced in this manner having a propionic acid content in the range of 5 to 70% by weight and in particular in the range of 10 to 65% by weight, based on the weight total of the compound (I). By means of the methods and variants of methods according to the invention, the compositions comprising the compounds of the formula (I) are obtained in solid and substantially pure form. These compositions comprising compounds of the formula (I) are novel and therefore a main subject of the invention. According to the invention, the compositions comprise at least one, e.g., 1, 2 or more, the compounds of the formula (I). Preferably, the compositions essentially comprise a compound of the formula (I), in particular in pure form, or a mixture of two compounds of the formula (I). The compounds of the formula (I) are distinguished, in particular, by a lower vapor pressure, compared to free propionic acid and therefore by increased stability and good malleability. The compositions according to the invention comprising compounds of the formula (I) can have a protonic acid content on the scale of 5 to 70% by weight and in particular on the scale of 10 to 65% by weight, based on the total weight of the composition. The content of propionic acid in the dried product can be determined in a common form, e.g., by titration of propionic acid with a base.

The compounds of the formula (I) or the compositions comprising these are usually obtained in crystalline form. They correspond essentially or completely to the formula (I): (Mn +) (H +) x (CH3CH2C (0) 0 '), n + x), x and n which have the meanings given above. It is essential for the invention in this context that the compositions have alkali metal (alkaline earth) propionate and propionic acid in associated crystalline form. The crystalline modifications obtained in the invention of the compounds of the formula (I) can be identified, for example, via broad-angle X-ray diffusion. Unwanted modifications, eg, neutral metal propionates, can be detected qualitatively in the same way by the same method. The X-ray diffraction peaks are established in the present application in the form of frame separations [A] independent of the wavelength of the x-rays used, which can be calculated from the diffraction angle measured by the Braga equation . Generally, the powder X-ray diffractogram of the compositions according to the invention has all the diffraction peaks characteristic of the special crystal structure as set forth above, eg, for sodium propionates or calcium propionates of acid produced by the method according to the invention. Depending on the degree of crystallinity and the texturization of the resulting crystals, however, the weakness of the intensity of the diffraction peaks in the powder X-ray diffractogram may occur, which may go as far as the low intensity diffraction peaks. individual and can not be detected in the powder X-ray diffractogram. The individual low intensity diffraction peaks, therefore, may be absent or the intensity ratio in the powder X-ray diffractogram may be changed. The presence of all diffraction peaks respectively established in the powder X-ray diffractogram indicates that these are compositions having one or more compounds (I) of particularly high crystallinity. It is obvious that those skilled in the art that the compositions of the invention or compounds (I), in addition to the characteristic diffraction peaks respectively established, may have additional diffraction peaks. In addition, mixtures of the compositions of the invention comprising the compounds (I) with other generally crystalline compounds have additional diffraction peaks. By means of differential scanning calorimetry (DSC), in the case of the compositions of the invention, one or more phase transition points can commonly be observed. It is assumed that each phase transition point should be assigned to another compound of formula (I) so that the presentation of two peaks in DSC indicates the presence of two compounds of formula (I) in the compositions of the invention. However, this interpretation will not be considered limiting, since, e.g., an individual compound of the formula (I) having two phase transition points may be present. The fraction of the compounds of the formula (I), if appropriate, in the dry compositions obtained from the method according to the inventions is commonly at least 97% by weight, in particular at least 98% by weight and especially at least 99% by weight, in each case based on the total weight of the dry composition. In this context, the expression "essentially in pure form" should also be understood, for the purposes of the present invention, that compositions of the invention comprising one or more compounds of the formula (I) may comprise, as additional components, e.g., belonging to the residual moisture or crystallized residual moisture, generally up to 1.5% by weight of propionic acid, up to 1.5% by weight of neutral alkaline metal (alkaline earth) propionate and / or up to 1% by weight of water , in each case based on the total weight of the composition. In particular, the water content in the compositions of the invention, if appropriate after a drying step has been carried out, is almost .5% by weight, based on the total weight of the composition. Especially in the production variant (Al), the values are often markedly below the limit values. In addition, the compounds obtained in the formula (I) are sufficiently stable to ensure easy handling and (in addition) processing. In addition, the content of potassium ions of the compositions obtained as long as Mn + is not potassium, is generally about 1000 ppm and in particular at most 500 ppm, in each case based on the total weight. The chloride content due to the production conditions in the compositions obtained in the invention is generally less than 1500 ppm, and in particular less than 1000 ppm, in each case based on the total weight. The aqueous solutions of the compositions of the invention comprising compounds of the formula (I) generally have pH which differ markedly from the pH of propionic acid solutions of the same concentration or of the corresponding neutral propionates. For example, eg, a 10% strength by weight solution of sodium dipropionate at 20 ° C has a pH of 4.9 and a resistance of 10% by weight of sodium tripropionate solution has a pH of 4.6 , whereas a resistance of 10% by weight of the neutral sodium propionate solution at 20 ° C has a pH of 7 to 8. A resistance of 10% by weight of the dicalcium pentapropionate solution has, at 20 ° C , a pH on the scale of 5 to 6, while a resistance of 10% in solution by weight of neutral calcium propionate has, at 20 ° C, a pH on the scale of 8 to 10. A resistance to 10% in weight of the propionic acid solution, in contrast, has a pH of 2.5 at 20 ° C. The resulting solid product, therefore, before and / or after can have a drying step, can be ground, e.g., by means of mortars, cutting apparatus, chopping presses and cylinder mills. Agglomerates, e.g., by means of mixers, and / or compacted, e.g., by means of presses and compactors. The apparatuses used for said crushing are known to those skilled in the art. Depending on the desired application, the composition produced according to the invention and comprising one or more compounds of the formula (I) can be further processed, powders of particular defined particle sizes can be generated, the generated particles can be covered with coatings and / or mixtures with other additives. As examples of coatings and coating materials, mention may be made of oils such as soybean oil, fatty acid fats such as palmitic or stearic acid, or polymeric coatings, e.g., made of polyalkylenes and derivatives thereof. The additives commonly, in particular, are flow aids such as silicic acid, etc. The common methods for coating and also the additives that come into consideration thereof are known in principle to those skilled in the art for the respective field, see for example, DE 102 31 891 A1. According to the invention, the composition produced it is of solid form, in particular as crystallized powder, or as granules or compacts. Depending on the requirements for use, the powders, granules or compacts have a mean particle size in the range from 1 μm to 10000 μm, in particular from 10 μm to 1000 μm and especially from 100 μm to 500 μm. The solid composition produced according to the invention and comprising at least one compound of the formula (I), or formulations comprising them, are particularly suitable for use as silage agents or silage additives in the production of silage. The reduction in pH caused by them, eg, to the order of magnitude of approximately 3 to 4, counteracts an occurrence of putrefactive bacteria, in particular, the development of harmful yeasts is inhibited. Fermentation of lactic acid can be accelerated, or secondary fermentation can be prevented. The solid composition produced according to the invention and comprising at least one compound of the formula (I) is also suitable so that the acidifier is washed. Acidifiers are substances with lower pH. The expression not only comprises substances with lower pH in the substrate (eg, animal feed), but also those with lower pH in the gastrointestinal tract of an animal. The solid composition produced according to the invention and comprising at least one compound of the formula (I) is also suitable as a preservative, in particular as a preservative for forage and / or animal breath. The solid composition produced according to the invention and comprising at least one compound of the formula (I) is also suitable as a food supplement. The solid composition produced according to the invention and comprising at least one compound of the formula (I) or formulations comprising the same are also suitable for use in food products for animals, in particular, as an additive for animal feed in the form of food additives and especially as additives for premixes for food products for animals. Premixes are mixtures that usually comprise minerals, vitamins, amino acids, trace elements and if appropriate enzymes. A foodstuff for animals and food additives comprising the solid composition produced according to the invention and comprising compounds of the formula (I) are particularly suitable for monogastric animals such as pigs, especially piglets, pigs and swine, and also poultry birds, especially chickens, chickens, turkeys, ducks, geese, quail, pheasants and ostriches. Depending on the other substances or additives present in the food product or food additives, the content of the solid composition produced according to the invention and comprising compounds of the formula (I) in the foodstuff or additive of the foodstuff can vary greatly. In food additives, the content also depends on the type of formulation, e.g., in the addition of auxiliaries such as desiccators, in a possible coating and in the residual moisture content. Commonly, the solid composition content produced according to the invention and comprising the compounds of the formula (I) in the food additive, e.g., is in the range of 0.1 to 99.5% by weight, in particular of 0.5 to 75% by weight, and especially 1 to 50% by weight, based on the total drying weight of the food additive. The solid composition produced according to the invention and is also suitable for use in a premix and therefore can be used in this case, e.g., added in customary amounts.

In particular, in the case of being used in food products and additives of food products for animals, especially birds, a low content of potassium ions is advantageous, since potassium in this case may exhibit a diuretic action. The use of compositions produced according to the invention in which Mn + is, eg, sodium, for the purpose mentioned above, represents a source of sodium acid propionate without the need to increase the potassium ion fraction. For example, an additive of solid food products can be formulated which comprises the solid composition or compound (I) produced according to the invention and is essentially free of potassium ions. In this case, essentially free of potassium ions means that the content of potassium ions is almost 1000 ppOm, and in particular 500 ppm, in each case based on the weight of the food additive. The food products for animals are composed in such a way that the corresponding nutrient requirement for the respective animal species is optimally covered. Generally, components of plant food products such as corn, wheat or barley meal, complete soy meal, soybean meal, flaxseed meal, rapeseed meal, green meal or peas meal are usually select as sources of crude protein. To ensure the corresponding energy content in the food product, soybean oil or other animal or vegetable fats are added. Because the plant protein sources comprise some essential amino acids only in insufficient quantity, the food products are frequently enriched with amino acids. These are mainly lysine and methionine. Minerals and addition vitamins are added to ensure the supply of minerals and vitamins from farm animals. The type and amount of minerals and vitamins depends on the species of animal and is known to those skilled in the art (see, e.g., Jeroch et al., Emáhrung Landwirtschaftlicher Nutztiere [Nutrition of farm animáis], Ulmer, UTB). To cover the nutrient and energy requirement, whole foods can be used which comprise all the nutrients in a relationship among others that cover the requirements. They can form the only food for animals. Alternatively, a supplementary food can be added to a grain food made from cereals. This refers to mixtures of foods rich in proteins, minerals and vitamins whose supplements feed. For many purposes mentioned above, in particular in the field of animal nutrition, the products and preservatives and silage, it may be advantageous to combine the compositions of the invention comprising at least one compound of the formula (I) with additional known solids for said purposes in a formulation. A suitable substance for this, in particular, sodium acid diformate in solid form described in the German application prior DE 10 2005 017 089.7 of the applicant. The following examples serve to illustrate the invention and in no way be taken as limiting. Examples Production Method A Variant Al Example 1: Sodium Tripropionate [NaH2 (CH3CH2C (O) O) 3] 550 g of propionic acid and 350 g of sodium propionate were added to a 0.5 1 beaker equipped with jacketed, lower outlet valve, anchor stirrer and cryostat and heated to 70 ° C until a homogeneous melt was obtained. The fusion was dried metal coated dwarf and allowed to cool. The resulting solid (858 g) which was triturated and dried for 6 h at 45 ° C under a water jet vacuum had a propionic acid content of 61.64% by weight and a water content of 0.08% by weight.

Example 2: Acid Sodium Propionate [NaH? .3 (CH3CH3CH2C (O) O) 2.3] The procedure of Example 1 was followed, using 400 g of propionic acid and 400 g of sodium propionate. The resulting crushed solid (762 g) had a propionic acid content of 49.77% by weight, a water content of 0. 03% by weight.

Example 3: Sodium dipropionate [NaH (CH3CH2C (O) O) 2] The procedure of example 1 was followed, using 390 g of propionic acid and 500 g of sodium propionate and the mixture being heated to 165 ° C until a homogeneous liquid mixture was obtained. The resulting crushed solid (817 g) had a propionic acid content of 43.46% by weight and a water content of 0.19% by weight.

Variant A2 Example 4: Acid Calcium Propionate [CaHo.4 (CH3CH2C (0) 0) 2.4] 680g of propionic acid and 590 g of calcium propionate were added to a shaking vessel 1 1 equipped with jacketed, lower outlet valve, anchor stirrer and cryostat and heated at 134 ° C until a solution was obtained. The solution was slowly cooled to 22 ° C, in which case crystallization started. After cooling, the crystallized solid was obtained by centrifugation (470 g, of which 0.93% by weight of water). The resulting solid which was dried overnight at 50 ° C under a water jet vacuum had a propionic acid content of 13.86% by weight and a water content of 0.42% by weight.

Production Method B Example 5: Sodium Tripropionate [NaH2 (CH3CH2C (O) O) 3] 800 g of propionic acid, 450 g of sodium propionate and 100 g of water were added to a 1 1 glass of stirring equipped with shirt, lower outlet valve, anchor stirrer and cryostat and heated to 50 ° C until a solution was obtained. The solution was cooled to 31 ° C and then seeded with 1 g of sodium tripropionate crystals. The reaction mixture was cooled to 22 ° C. After cooling, the crystallized solid was obtained by centrifugation (249 g, of which 2.18% by weight of water.9 The resulting solid which was dried overnight at 40 ° C under a water jet vacuum had a propionic acid content. of 61.29% by weight and a water content of 0.06% by weight.

Example 6: Calcium propionate of acid [CaH0.4 (CH3CH2C (O) < 0) 2.4_ 750 g of propionic acid, 575.8 g of calcium propionate and 38.6 g of water were added to a stirred value of 1 1 equipped with jacket, lower outlet valve, anchor stirrer and cryostat and heated to 125 ° C until a solution was obtained. The solution was cooled to 112 ° C and then seeded with acid calcium propionate crystals. The reaction mixture was cooled to room temperature, in which case the crystallization started at 109 ° C. After cooling, the crystallized solid was obtained by centrifugation. The resulting solid (302.6 g) which was dried at 75 ° C under a water jet vacuum had a propionic acid content of 13.73% by weight and a water content of 0.05% by weight.

Example 7: Calcium Acid Propionate [CaHo.4 (CH3CH2C (O (O) 2 4] 621.2 g of propionic acid, 543 g of calcium propionate and 155.3 g of water were added to a 1 liter tumbled cup equipped , lower outlet valve, anchor stirrer and cryostat and heated to 77 ° C until a solution was obtained.The solution was cooled to 70 ° C and then seeded with calcium acid propionate crystals. cooled to room temperature, in which case the crystallization started at 65 ° C. After cooling, the crystallized solid was obtained by centrifugation (129.9 g, of which 1.61% by weight of water) .The resulting solid was dried at 75 ° C. under a water jet vacuum it had a propionic acid content of 13.89% by weight and a water content of 0.01% by weight.

Analysis of X-Ray Structure The crystal structures of the compounds [CaH0.4 (CH3CH2C (O) O) 2. ] (structure 1) and [NaH2 (CH3CH2C (O) o) 3] (structure II) obtained from the production examples were determined by direct methods using the SHELXTL program. The correct positions of calcium and sodium atoms were derived from map E. By refinement of subsequent "least squares" (ie, Least Squares Method) and the calculation of differential electron density, the atoms without residual hydrogen were assigned. The atoms were anisotropically refined and the hydrogen atoms adjusted to idealized positions. Tables 4 and 5 below summarize the results thus obtained. [CaH0.4 (CH3CH2C (0) 0) 2.4] (structure I) Table 4 a, b, c = length of the edges of the unitary cell a, ß,? = unit cell angles Z = number of molecules in the unit cell Rl = S || F0 | - | Fc | | / S | F0 I wR2 =. { S [w (F02-F02) 2] / S [w (F02) 2 [} 1 2 The asymmetric unit of the crystal of structure I is shown in Fig. 1 and comprises four fractions of Ca propionate and a fraction of uncharged propionic acid. A calcium ion sits in a special position and counts only 1/2. The coordination of calcium ions are not very symmetric. The hydrogen of the OH group forms a hydrogen bond to the adjacent propionate. If a plurality of unit cells are observed together, it is possible to observe the way in which the crystal is composed of two layers. Methyl groups develop hydrophobic surfaces at the top and bottom. Between them there is a layer that has ionic interactions. In one orientation, tube-like structures form a polar core and hydrophobic surface.

[NaH2 (CH3CH2C (0) 0) 3] (structure II) Table 5 a, b, c = length of the edges of the unitary cell a, ß,? = unit cell angles Z = number of molecules in the unit cell Rl = S | | F0 I - I Fc | | /? I F0 I wR2 =. { S [(F02-F02) 2] / S [w (F02) 2 [} 1/2 The asymmetric unit of the crystal of structure II is shown in Fig. 2 and comprises 2 fractions of Na propionate and 4 fractions of propionic acid. Although the R factor is very poor at 0.22, the correctness of the structure is assumed without any binding restriction of the invention as observed herein. The palette crystals that are slightly twisted one on top of the other can explain the altered resolution. When a plurality of unit cells is considered, it is observed that the tubular structure present is more pronounced than in the case of structure 1.

Claims (17)

1. CLAIMS 1. A composition comprising propionic acid in solid and essentially pure form, comprising at least one compound according to formula (I) (Mn +) (H +) x (CH3CH2C (0) 0 ~) (n + x) ( I), where Mn + is sodium; n being equal to 1 or 2; and x is a number on the scale from 1.8 to 2.2; and [NaH2 (CH3CH2C (0) 03] and [aH ^ (CH3CH2C (O) 02.3] 2. The composition according to claim 1, the compound of the formula (I) being present in crystalline form. The composition according to one of the preceding claims having a water content of at least 1% by weight based on the total weight of the composition 4. The composition according to the claim 1, which, in the powder X-ray diffractogram, exhibit diffraction peaks of at least 4 of the following frame separations d: 13.63; 13.13, 13.03; 11. 09; 9.71; 9.59; 3.94; 2.84; 2.79 [A] (± 0.04 [A]). 5. The composition according to claim 1, which at a temperature of 61 ° C, determined by means of differential scanning calorimetry, exhibits a phase transition point. 6. A method for producing a composition comprising propionic acid in solid and essentially pure form, comprising at least one compound according to formula (I) (Mn +) (H +) x (CH3CH2C (0) 0") (n + x) (I), where Mn + is sodium, n being equal to 1 or 2, and x is a number on the scale of 0.25 to 5, in which a homogeneous mixture is produced from the neutral alkali metal propionate or alkaline earth metal propionate and propionic acid in a molar ratio in the scale of 1: 0.25 to 1.5, with heating and the homogenous mixture solidifying, and the water content of the homogeneous mixture, at least at the beginning of solidification, and in Particular also during the same, being less than 1% by weight, based on the total weight of the mixture 7. The method according to claim 6, the homogeneous mixture being at least partly solidified by cooling and / or evaporation, if appropriate in the presence of seed crystals of the compound of the f Ormula (I). 8. - The method according to claim 6 or 7, the molar ratio of the neutral alkali metal propionate to propionic acid in the homogeneous mixture being on the scale from 1:04 to 1: 3. 9. - A method for producing a composition comprising propionic acid in solid and essentially pure form, comprising at least one compound according to formula (I) (Mn +) (H +) x (CH3CH2C (0) 0-) ( n + x) (I), where Mn + is sodium; n being equal to 1 or 2; and x is a number on the scale of 0.25 to 5; wherein a homogeneous mixture is produced from the neutral alkali metal propionate or alkaline earth metal propionate and propionic acid in a molar ratio in the range of 1: 0.25 to 1.5; with heating and the homogenous mixture solidifies, and the water content of the homogeneous mixture, at least at the beginning of solidification, and in particular also during the mime, being on the scale of 1 to 15% by weight, based on the total weight of the mixture. 10. The method according to claim 9, the homogeneous mixture being crystallized by cooling and / or evaporation, if appropriate in the presence of seed crystals of the compound of the formula (I). 11. - The method according to claim 9 or 10, x being on the scale from 1.8 to 2.2. 12. The method according to one of claims 6 to 11, the compound of the formula (I) being obtained in crystalline form. 13. The method according to one of claims 6 to 12, the compound of the formula (I), if appropriate after a drying step, being obtained in dry form having a water content of almost 1% in weight, based on the total weight of the composition. 14. A composition of the formula (I) as defined in claim 1 in solid and essentially pure form obtainable by a method according to one of claims 6 to 13. 15. The composition according to claim 14, which can be obtained by a method according to one of claims 15 to 18, 21 or 22, Mn + being sodium, x being on the scale of 0.4 to 3, and the composition, on the powder X-ray diffractogram , exhibiting diffraction peaks in at least four of the following d-frame separations: 13.63; 13.13; 13.03; 11.09; 9.71; 9.59; 3.94; 2.84; 2.79 [A] (± 0.04 [A]) and / or the composition, at a temperature of 61 ° C, determined by means of differential scanning calorimetry, exhibiting a phase transition point; and the composition being obtained if appropriate in a manner as defined in claim 12 and / or 13. 16. The use of a composition as defined in one of claims 1 to 5, as a silage additive, preservative, acidifier, food supplement, food product or food product additive for animal feed. 17. The use of a composition obtainable by a method according to one of claims 6 to 13, as a silage additive, preservative, acidifiers, food supplement, food product or food product additive for animal feed.