VEGETABLE OIL COMPOSITION FOR COATING PARTICLES

Abstract

The present invention relates to a coating composition comprising at least from 1% by weight to 30% by weight, limits included, of a surfactant, preferably a nitrogen-containing surfactant, and from 5% by weight to 99% by weight, limits included, of a cyclic alcohol, comprising 12 to 100 carbon atoms, limits included, and of derivatives of this.

The present invention also relates to the granular material coated with said composition.

Claims

1. A coating composition comprising at least: from 1% by weight to 30% by weight, limits included, of a surfactant; from 5% by weight to 99% by weight, limits included, of a cyclic alcohol, comprising 12 to 100 carbon atoms, limits included, and of derivatives thereof, wherein, when the cationic surfactant is a nitrogen-containing surfactant, the surfactant is selected from primary amines and secondary amines.

2. The composition as claimed in claim 1, wherein the surfactant is selected from anionic surfactants and cationic surfactants, as well as the mixtures thereof.

3. The composition as claimed in claim 1, wherein the surfactant is selected from primary amines and secondary amines, and their salts.

4. The composition as claimed in claim 1, wherein the surfactant is a mixture comprising at least one cationic surfactant and at least one anionic surfactant selected from monoalkyl esters of phosphoric acid, dialkyl esters of phosphoric acid, alkoxylated monoalkyl esters of phosphoric acid, alkoxylated dialkyl esters of phosphoric acid, alkyl esters of sulfuric acid, alkoxylated alkyl esters of sulfuric acid, alkylsulfonic acids, arylsulfonic acids, alkoxylated alkylsulfonates and (alkyl ether)sulfonates.

5. The composition as claimed in claim 1, wherein the surfactant is a mixture comprising at least one surfactant selected from primary amines and secondary amines, and their salts, and at least one alkyl ester of phosphoric acid.

6. The composition as claimed in claim 1, wherein the surfactant(s) is(are) present at dosages ranging from 1% by weight to 25% by weight, limits included, with respect to the total coating composition.

7. The composition as claimed in claim 1, wherein the cyclic alcohol has a molecular weight of greater than 100 g.Math.mol.sup.−1.

8. The composition as claimed in claim 1, wherein the cyclic alcohol is selected from phytosterols.

9. The composition as claimed in claim 1, wherein the cyclic alcohol is present at dosages ranging from 7% by weight to 80% by weight, limits included, with respect to the total coating composition.

10. The composition as claimed in claim 1, further comprising one or more other components selected from: rheology modifiers, waxes, amidoamides, alkylamidoamides; hydrophobizing agents, macrocrystalline waxes; dispersing agents; dyes, UV tracers, pigments, colorants; mineral and/or organic micronutrients and trace elements which can be finely dispersed and/or compatibilized; biostimulants; pesticides; bacteria, yeasts, fungi, viruses; antioxidants, preservatives, UV stabilizers; odor-masking agents, antiodorants, aromas, fragrances; and also mixtures of two or more of the components listed above.

11. A method for coating a granular material selected from fertilizers, coal, ores, mineral aggregates, sulfur, wood chips, dirt, granulated waste, medicaments, cereals, granulated animal feed and the like, comprising contacting the granular material with the composition as claimed in claim 1.

12. A granular material coated with the composition as claimed in claim 1.

13. The granular material as claimed in claim 12 which is a fertilizer granule.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0055] A “fertilizer”, within the meaning of the present invention, is a particle of inorganic and/or organic material which provides the soil and/or crops with mineral and/or organic nutrients or other substances which improve their growth. The fertilizer particles can originate from any known process for producing fertilizers, such as granulation, grinding, mixing or formulating, compacting or prilling.

[0056] Preferably, the fertilizer particles comprise nitrates, such as ammonium nitrates, nitrophosphates, ammonium phosphate sulfate, ammonium sulfate, calcium ammonium nitrates, calcium nitrate, diammonium phosphate, potassium chloride, monoammonium phosphate, muriate of potash, sulfate of potash, sulfate of potash magnesia, single superphosphate, triple superphosphate, urea, sulfur, polyhalite and other complex or composite fertilizers which contain several elements, and, for example, those known under the acronym NPK.

[0057] The composition of the present invention can be applied using techniques well known in the art and commonly used for the coating of particulate materials, such as those well known and used for the coating of granulated fertilizers, for example according to well-known spray coating techniques. This can be carried out using a batch or continuous process. For example, the granulated fertilizer can be introduced into a rotary coating drum while the coating is applied via one or more pressurized nozzles. The coating can also be sprayed while the granulated fertilizer rotates on an inclined granulation drum or is within a fluidized-bed chamber.

[0058] The stage of coating with the coating composition of the present invention can be carried out before one or more coatings of other material and/or at the same time as these and/or after these, such as, for example, the coating of additional nutrients or biological functions which are useful for soils or animals or plants, the coating of anti-caking agents, such as, for example, clays (for example kaolin), talc, and the like.

[0059] In a preferred embodiment, the stage of coating with the coating composition of the invention is carried out before one or more coatings of an additional ingredient which is talc and/or at the same time as these and/or after these.

[0060] Once applied to the surface of the particulate material, the amount of coating composition coated on said particulate material can vary widely. Such an amount advantageously and preferably amounts to an amount of between 0.02% by weight and 2% by weight, limits included, with respect to the total weight of the coated granular material.

[0061] The present invention also relates to the granular material coated with the composition of the present invention. Once applied to the surface of a granular material (for example and preferably a fertilizer granule), the composition of the present invention proves to be effective for achieving one or more of the following objectives: [0062] reducing or preventing the agglomeration of the coated particles, [0063] reducing or preventing the release of dust from the coated particles, [0064] reducing or preventing the absorption of moisture into the coated particles, [0065] binding, to the coated particle, other mineral or organic particles which can provide an additional nutrient or additional biological functions to soils or to animals or to plants, these mineral or organic particles being added to the particle before or after the composition of the present invention is applied.

[0066] The composition of the present invention, based on a renewable and advantageously biodegradable oil, confers effective protection against agglomeration and dust on particles, and in particular fertilizers. Such properties of protection against agglomeration and dust have proved to be better than those of conventional known coating compositions.

[0067] According to a preferred embodiment, the present invention relates to a fertilizer granule coated with a composition of the present invention. In another preferred embodiment, the particulate material, for example a fertilizer particle, is coated with a composition of the invention at a dosage of between 0.02% by weight and 2% by weight, limits included, with respect to the total weight of the coated particulate material.

[0068] The composition of the present invention makes it possible to obtain coated particles, and preferably coated fertilizer particles, exhibiting one or more of the advantages listed below, among which may be mentioned: [0069] there is no chemical reaction between the composition and the coated particle, [0070] the coating composition is not a polymer (a change in European law is currently underway to reduce and even eliminate the uses of polymers in fertilizers), [0071] compatibility with several types of oils from renewable sources, such as refined or crude oils or distillation residues, [0072] the coating process is the same as the current processes known in the art for coating particles (same spraying/coating equipment, same spraying temperatures).

[0073] The composition of the present invention can be used in a certain number of other fields of application and is in particular suitable for the coating of particles which exhibit a tendency to clump or to agglomerate and/or to generate dust, such as cereals, flours, medicaments, ceramics, mineral aggregates originating from quarries, and the like.

[0074] It is compatible with other commonly used components of coatings of fertilizers, such as surfactants, alcohols, waxes, colorants and the like.

[0075] The invention is further illustrated below by the following examples, which are presented as embodiments of the invention only, without bringing about any limitation of the scope of protection as defined by the appended claims.

EXAMPLES

Example 1

[0076] A comparative composition, comparative composition A, is prepared by mixing 10 g of a fatty amine surfactant, sold under the name Noram® SH by Arkema, 25 g of a microcrystalline mineral wax (freezing point >65° C., originating from Lotos Company) and 65 g of a mineral oil with a kinematic viscosity at 40° C. of between 130 mm.sup.2.Math.s.sup.−1 and 220 mm.sup.2.Math.s.sup.−1 (sold by Colas under the trade name “700S”). All the components are mixed at 90° C. until they are completely homogenized.

[0077] Another composition, comparative composition B, is prepared by mixing 10 g of a fatty amine surfactant, sold under the name Noram® SH by Arkema, 25 g of a microcrystalline mineral wax (freezing point >65° C., originating from Lotos Company) and 65 g of a degummed soybean oil originating from Cefetra. All the components are mixed at 90° C. until they are completely homogenized. Degumming is a well-known refining process in which the impurities of soybean oil, in particular the phosphatides or the gums, are removed from the crude vegetable oil. This vegetable oil does not contain amounts greater than traces of cyclic alcohols and of their derivatives. The presence, the nature and the amount of cyclic alcohols, as well as of derivatives of these, can be easily identified by standard analytical methods well known to a person who is a specialist in qualitative and quantitative analytical techniques, such as column chromatography coupled with mass spectrometry.

[0078] Another composition, composition C, according to the invention, is prepared by mixing 10 g of a fatty amine surfactant, sold under the name Noram® SH by Arkema, 25 g of a microcrystalline mineral wax (freezing point >65° C., originating from Lotos Company) and 65 g of a residue originating from tall oil, sold under the name Resinoline L by DRT. All the components are mixed at 90° C. until they are completely homogenized. This type of residue originating from tall oil contains more than 20% by weight of cyclic alcohols, which results in a content of at least 13% by weight of cyclic alcohol in the final coating composition. The viscosity of the tall oil residue used is measured using an Anton Paar MCR301 dynamic shear rheometer in a 50 mm parallel plate (PP50) geometry, between 50° C. and 10° C. at a shear rate of 80 s.sup.−1, which gives a value of 212 mPa.Math.s at 25° C.

[0079] Another comparative composition, composition D, is prepared by mixing 3.6 g of a fatty amine surfactant, sold under the name Noram® SH by Arkema, 6.4 g of an alkoxylated phosphoric acid ester surfactant, comprising a hydrocarbon chain comprising 16 to 18 carbon atoms and 4.5 ethylene oxide units (Surfaline® PE684 by Arkema), 25 g of a microcrystalline mineral wax (freezing point >65° C., originating from Lotos Company) and 65 g of a mineral oil with a kinematic viscosity at 40° C. of between 130 mm.sup.2.Math.s.sup.−1 and 220 mm.sup.2.Math.s.sup.−1 (sold by Colas under the name 700S). All the components are mixed at 90° C. until they are completely homogenized.

[0080] Another comparative composition, composition E, is prepared by mixing 3.6 g of a fatty amine surfactant, sold under the name Noram® SH by Arkema, 6.4 g of an alkoxylated phosphoric acid ester surfactant, comprising a hydrocarbon chain comprising 16 to 18 carbon atoms and 4.5 ethylene oxide units (Surfaline® PE684 by Arkema), 25 g of a microcrystalline mineral wax (freezing point >65° C., originating from Lotos Company) and 65 g of a degummed soybean oil originating from Cefetra. All the components are mixed at 90° C. until they are completely homogenized.

[0081] Another composition, composition F, according to the invention, is prepared by mixing 3.6 g of a fatty amine surfactant, sold under the name Noram® SH by Arkema, 6.4 g of an alkoxylated phosphoric acid ester surfactant, comprising a hydrocarbon chain comprising 16 to 18 carbon atoms and 4.5 ethylene oxide units (Surfaline® PE684 by Arkema), 25 g of a microcrystalline mineral wax (freezing point >65° C., from Lotos Company) and 65 g of a residue originating from tall oil, sold under the name Dertal by DRT. All the components are mixed at 90° C. until they are completely homogenized. This residue originating from tall oil contains more than 20% by weight of cyclic alcohols, which results in a content of at least 13% by weight of cyclic alcohol in the final coating composition. The viscosity of the tall oil residue used is measured using an MCR301 dynamic shear rheometer (Anton Paar) in a 50 mm parallel plate (PP50) geometry, between 50° C. and 10° C. at a shear rate of 80 s.sup.−1, which gives a value of 3800 mPa.Math.s at 25° C.

[0082] The properties, as protective coating against agglomeration, are evaluated in the following example 2.

Example 2

[0083] The following tests are carried out in order to evaluate the tendency to agglomeration of a sample of coated ammonium nitrate (AN 33.5), after having been subjected to heat and pressure and during transportation.

[0084] Compositions A and B (comparative compositions) as well as composition C (according to the invention) originating from example 1 are used as coating on AN granules. 500 g of AN granules are heated at 40° C. for 4 hours before being mixed in an open-end laboratory coating drum and sprayed with 0.5 g of coating composition sample, at 90° C.

[0085] Similarly, compositions D and E (comparative compositions) as well as composition F (according to the invention) originating from example 1 are used as coating on AN granules. 500 g of AN granules are heated at 40° C. for 4 hours before being mixed in an open-end laboratory coating drum and sprayed with 0.5 g of coating composition sample, at 90° C.

[0086] An accelerated agglomeration test is carried out with the coated samples. Metal molds were filled with 150 g of the coated AN granules, closed and subjected to a constant pneumatic pressure of 3 bar for 24 hours. The temperature of the samples was maintained at 40° C. during the whole of the 24 hours. Three samples were prepared for each coated sample. An uncoated sample was also evaluated for comparison.

[0087] After 24 hours, the molds were carefully opened and compressed in a universal compression machine (Instron 3365). The breaking force of the samples was recorded in each case. Table 1 presents the integral values of the results obtained for each coating (breaking force in kilograms-force, kgf).

TABLE-US-00001 TABLE 1 -- Agglomeration of coated fertilizers -- Breaking Standard deviation Coating force (kgf) of the breaking force Uncoated 88.3 11.2 Composition A (comparative) 6.1 5.7 Composition B (comparative) 33.4 8 Composition C (invention) 6.4 2.3 Composition D (comparative) 7.2 4.3 Composition E (comparative) 8.4 1.7 Composition F (invention) 0 —

[0088] It can be seen that comparative composition A and composition C according to the invention provide excellent protection against similar agglomeration. However, comparative composition A is based on mineral oils, which are less suitable for agricultural applications given that they are not environmentally friendly. On the other hand, the compositions prepared with conventional vegetable oils, such as comparative composition B containing soybean oil, are not sufficiently effective in an anti-caking coating for fertilizers.

[0089] It can also be seen that comparative composition D, based on mineral oils, and E, containing soybean oil, provide fairly good protection against agglomeration. Without being committed to a theory, it might be that the coupled surfactants used are more compatible with soybean oil than in the preceding examples. Composition F, comprising cyclic alcohols, provides excellent protection against agglomeration and no agglomeration was observed under the conditions of the tests.

Example 3

[0090] The following tests are carried out in order to evaluate the tendency to agglomeration of a sample of coated NPK 15-15-15 complex fertilizer, after having been subjected to heat and pressure and during transportation.

[0091] Composition G (according to the invention) is prepared by mixing 5 g of a fatty amine surfactant, sold under the name Noram® SH by Arkema, with 15 g of phosphoric acid alkoxylated ester surfactant, comprising a hydrocarbon chain containing from 16 to 18 carbon atoms and 4.5 ethylene oxide units (sold under the name Surfaline® PE684 by Arkema), 10 g of hydrogenated castor oil (from Mosselman), 35 g of degummed soybean oil originating from Cefetra and with 35 g of a residue originating from tall oil, sold under the name Dertal by DRT. All the components are mixed at 90° C. until they are completely homogenized. This residue originating from tall oil contains more than 20% by weight of cyclic alcohols, which results in a content of at least 7% by weight of cyclic alcohol in the final coating composition.

[0092] An anti-caking composition A commercially available under the name Fluidiram® 780 from Arkema (formulation based on mineral oils, and not containing cyclic alcohol) is used by way of comparison.

[0093] This commercially available anti-caking composition AG and composition G (according to the invention) are used as coating agents on NPK 15-15-15 granules. The NPK 15-15-15 granules (500 g) are heated at 40° C. for 4 hours before being mixed in an open-end laboratory coating drum and sprayed with 1.25 g of coating composition sample, at 90° C.

[0094] An accelerated agglomeration test is carried out with the coated samples. Metal molds were filled with 150 g of the coated NPK 15-15-15 granules, closed and subjected to a constant pneumatic pressure of 3 bar for 24 hours. The temperature of the samples was maintained at 25° C. during the whole of the 24 hours. Three samples were prepared for each coated sample. An uncoated sample was also evaluated for comparison.

[0095] After 24 hours, the molds were carefully opened and compressed in a universal compression machine (Instron 3365). The breaking force of the samples was recorded in each case. Table 2 presents the integral values of the results obtained for each coating (breaking force in kilograms-force, kgf).

TABLE-US-00002 TABLE 2 -- Agglomeration of coated fertilizers -- Breaking Standard deviation Coating force (kgf) of the breaking force Uncoated 38.2 4.1 Commercial coating (comparative) 3.9 1.3 Composition G (invention) 1.6 1.1

[0096] It is observed that composition G comprising cyclic alcohols according to the present invention results in better protection against agglomeration than that observed with the commercial coating composition comprising mineral oils.