Organic copper chelate as well as preparation method and application thereof

Abstract

The invention relates to the field of animal nutrition and feed additives, in particular to an organic copper chelate as well as a preparation method and application thereof. The preparation method of the organic copper chelate comprises the following steps: (1) mixing amino acid, algal polysaccharides, trace element copper and an optional catalyst in the form of dry powder, and then adding a wetting agent accounting for 2-5% of the total weight of the materials for wetting treatment; (2) carrying out a pressing reaction on the humidified material under heating and pressurizing conditions; and (3) granulating a product obtained after the pressing reaction. According to the method, amino acid and algal polysaccharides are used as double organic ligands and are subjected to complex reaction with trace element copper under the action of a catalyst, and meanwhile, a compression molding process is combined, so that continuous integrated operation of reaction and molding is completed in the same system; and the method has the advantages of simple process, no wastewater, no organic solvent, high operation safety, high production efficiency and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of animal nutrition and feed additives, in particular to an organic copper chelate and a preparation method and application thereof. BACKGROUND

[0003] Green feed additives are important technical means to promote the healthy breeding of livestock and poultry, aquatic products, and new nutrition enhancers represented by organic trace element preparations are considered to be one of the core products to replace inorganic salt additives, reduce excretion pollution, and improve feed conversion efficiency due to their advantages of less pollution, high bioavailability, and good safety. In recent years, research on organic trace element products has been continuously deepened, and their functions cover promoting the proliferation of intestinal probiotics in animals, enhancing immunity, improving antioxidant capacity, and improving stress response, and their application value is increasingly prominent. However, there are still many problems in the actual use of currently marketed organic trace element products, such as unclear chelation ratio, single dosage form structure, large fluctuations in stability and absorption efficiency, easy to be affected by antagonistic factors in feed, and lack of systematic verification of bioavailability, which to some extent limit their popularization and application.

[0004] From the research basis, amino acid chelates and polysaccharide chelates as two core systems in organic trace elements have clear chemical structures and relatively stable functions. For example, small molecular amino acids such as methionine, lysine, and glycine form 1:1 or 2:1 complex structures with trace elements such as copper, zinc, and iron, which can significantly improve the bioavailability of metal ions; and natural macromolecules such as algal polysaccharides and sugar cane molasses can form a spatially stable multi-point complex network structure after interacting with metal ions, which helps to enhance the stability and slow release of metal chelates in the gastrointestinal tract. These two types of structures each have their own advantages, but single systems often lack complete protection mechanisms and have limited absorption and utilization processes, and complexation and synergism are gradually becoming a development trend.

[0005] In recent years, research on amino acid complexes or polysaccharide complexes as livestock feed has mainly focused on: 1. Chinese Patent Application No. 201010265360.6, entitled "Preparation method of methionine zinc", the main steps are: (1) salt formation step: put methionine, zinc oxide, initiator, and water into a reaction kettle, stir, heat at 70-80°C, make carbon dioxide overflow, and generate methionine zinc; (2) drying step: place the separated granular product in an upper and lower gas-permeable stainless steel drying sieve, put it into a drying oven, dry the product, and sieve to obtain methionine zinc product.

[0006] 2、Chinese patent application number: 201811406902.X, the invention name: a method for synthesizing zinc methionine chelate, the main steps are: glycerol and water are put into a reaction container, mixed and stirred, methionine, zinc salt and catalyst are added in turn during stirring, the catalyst is selected from one of sodium tartrate, sodium benzoate, sodium oxalate or sodium salicylate, the reaction is carried out at 1-5 standard atmospheres and a temperature of 105-250℃ for 0.5-6 hours: after the A step reaction is completed, filter the hot cake, rinse the cake with water, dry and crush the cake to obtain zinc methionine chelate.

[0007] 3、Chinese patent application number: 202010829433.3, the invention name: preparation method of feed additive DL-methionine zinc complex, the main steps are: heating the methionine aqueous solution to 60~80℃, keeping constant temperature, adding zinc salt, stirring, then adding methionine metal salt and the corresponding carbonate aqueous solution to adjust pH, heating to 60~110℃, reacting for 0.5-1.0 hours, then filtering and washing with normal temperature water to obtain methionine zinc product.

[0008] 4、Chinese patent application number: 201410463827.6, the invention name: trace element sucrose complex feed additive and its preparation method and application, the main steps are: adding copper sulfate, zinc sulfate, ferrous sulfate, manganese sulfate, calcium sulfate, magnesium sulfate and cobalt sulfate in the molasses solution at 85-105℃, fully reacting to obtain the complex, and finally obtaining the finished product after spray drying, crushing, screening and testing.

[0009] 5、Chinese patent application number: 200710030122.5, the invention name: method for preparing copper and zinc glycine complex by grinding solid phase, the main steps are: mixing glycine and copper and zinc metal compounds in a mortar at room temperature, grinding for 15-30 minutes, glycine and copper and zinc metal compounds react chemically, continue to grind for 40-80 minutes until the reaction is complete; wash the product with 75% ethanol twice; dry: first at room temperature, then at 80℃.

[0010] 6、Chinese patent application number: 201410463826.1, the invention name: organic multiple calcium complex feed additive and its preparation method and application, the main steps are: dissolving citric acid completely in water at 100℃, then adding excess calcium salt and reacting for 2-3 hours, then adding molasses and reacting for 1.5-2 hours, the whole reaction temperature is controlled at 85℃-100℃; after the reaction is completed, the product is obtained by precipitation, dehydration, drying, screening, testing and packaging.

[0011] 7. Chinese patent application No. 201610609869.5, entitled "Method for producing organic multiple complex feed additive with molasses as raw material", the main steps of which are: after the multi-element complex reaction of molasses and trace elements, corn flour, bean dregs, rice bran and fermentation strains are subjected to secondary fermentation; the weight parts of the molasses are 10-25 parts; the corn flour is 5-10 parts; the bean dregs are 5-8 parts; the rice bran is 5-8 parts; the fermentation strains are 0.1-1 part; the trace elements are 0.1-0.3 parts; the composition of the trace elements and the weight parts of each component are: ferrous sulfate 1-5 parts, zinc sulfate 1-4 parts, calcium oxalate 2-5 parts, manganese sulfate 1-4 parts, and copper sulfate 0.5-1 part.

[0012] In the above-mentioned patent application, the reaction system of 1-4 introduces a large amount of water, which belongs to the wet or water system synthesis method, and is easy to produce a large amount of wastewater and increase the reaction and drying time of the product, resulting in the problems of high energy consumption and wastewater treatment. Invention 5 is a solid-phase dry method system, but it introduces organic solvent ethanol, which has safety hazards in actual industrial production, and the treatment of recycled ethanol mother liquor also has difficulties. Inventions 6 and 7 are multiple complex reactions, which are characterized by using molasses and citric acid (fermented organic acid, etc.) to react with trace elements, and no amino acid is introduced in the process.

[0013] Therefore, there is no related preparation process in the field of feed additives that combines the advantages of amino acid complexes and polysaccharide complexes, and the existing dry, wet or water system synthesis method requires the introduction of a large amount of water, which produces a large amount of wastewater and increases the reaction and drying time of the product, thereby resulting in the problems of high energy consumption and wastewater treatment. In the existing other dry or solid-phase system synthesis method, organic solvent ethanol is introduced, which causes safety hazards in industrial production, and the treatment of recycled organic solvent mother liquor has difficulties. SUMMARY

[0014] To solve the above-mentioned problems caused by the large amount of solvent added in the existing preparation process, the present application provides an organic copper chelate and its preparation method and application.

[0015] To solve the above-mentioned technical problems, one of the technical solutions provided by the present application is as follows: A preparation method of an organic copper chelate, comprising the following steps: Step (1), mixing amino acid, seaweed polysaccharide, trace element copper and optional catalyst in the form of dry powder, and then adding 2% to 5% of a wetting agent based on the total weight of the material for wetting treatment; Step (2), pressing the material after wetting treatment under heating and pressurization conditions for compression reaction; Step (3), granulating the product after compression reaction.

[0016] In the present application, two different types of organic ligands (amino acids and polysaccharides) are used to form coordination or chelation structures with copper ions, respectively. Due to the release of crystal water in the copper source during the pressing reaction, accompanied by an exothermic reaction, the reaction between the copper source and the organic ligand is further promoted. The reaction is carried out in a high-temperature and high-pressure vacuum control system, which ensures the sufficiency of the reaction and the stability of the product. 2+ The reaction is carried out in a high-temperature and high-pressure vacuum control system, which ensures the sufficiency of the reaction and the stability of the product.

[0017] In an embodiment of the present application, the amino acid in step (1) is selected from at least one of glycine, DL-methionine, L-methionine, L-lysine hydrochloride, L-lysine sulfate, L-threonine, L-tryptophan, L-valine, and L-glutamic acid.

[0018] In an embodiment of the present application, the seaweed polysaccharide in step (1) is selected from at least one of Enteromorpha polysaccharide, brown algal oligosaccharide, Ulva polysaccharide, and brown algal polysaccharide.

[0019] In an embodiment of the present application, the trace element copper in step (1) is selected from at least one of copper sulfate, copper chloride, and basic copper chloride.

[0020] In an embodiment of the present application, the catalyst in step (1) is a basic compound, preferably, the basic compound is selected from at least one of sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, and potassium carbonate; and / or The wetting agent in step (1) is deionized water.

[0021] In an embodiment of the present application, the molar ratio of the amino acid, seaweed polysaccharide, and trace element copper in step (1) is (0.5-2):(0.5-2):(0.2-1).

[0022] In an embodiment of the present application, the temperature of the heating in step (2) is 50°C to 60°C, and the pressure is 25 MPa to 35 MPa; and / or The pressing reaction in step (2) is carried out under a vacuum degree of ≤1000 Pa.

[0023] Based on the "dry-state dispersion catalyst + micro-wet linkage pressing system" adopted in the present application, the catalyst no longer relies on liquid medium excitation, but forms a high local pH reaction microenvironment under the triple action of pressing-temperature rising-vacuum extraction, thereby efficiently promoting the formation of complex bonds. This method is significantly superior to the efficiency and safety of traditional wet complexation or stepwise reaction, and the chelation rate can reach more than 95% under the condition of controlling the temperature in a lower range and reducing the molar amount of organic ligands.

[0024] In an embodiment of the present application, the humidification treatment, the pressing reaction and the granulation step are performed continuously in the same device.

[0025] The second technical solution of the present application is as follows: The organic copper chelate prepared by the method described above.

[0026] The third technical solution of the present application is as follows: The application of the organic copper chelate described above in a feed additive.

[0027] The present application provides a dry one-step forming preparation method of amino acid-polysaccharide-microelement copper organic copper chelate; the method realizes the continuous integrated operation of "reaction+forming" in the same system by complexing reaction of amino acid and seaweed polysaccharide as double organic ligands with microelement copper under the action of a catalyst, and combining with a pressing forming process; the method has the advantages of simple process, no wastewater, no organic solvent, high operation safety, high production efficiency and the like.

[0028] Other features and advantages of the present application will be set forth in the description that follows, and in part will become apparent to those skilled in the art upon examination of the following or can be learned by practice of the present application. The objects and other advantages of the present application can be realized and attained by the structure particularly pointed out in the description and claims of the present application. DETAILED DESCRIPTION

[0029] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are some of the embodiments of the present application but not all the embodiments of the present application; the technical features designed in different embodiments of the present application can be combined with each other as long as there is no conflict. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0030] In the description of the present application, it should be noted that all the terms (including technical terms and scientific terms) used in the present application have the same meaning as that generally understood by those skilled in the art to which the present application belongs, and should not be understood as a limitation on the present application; it should be further understood that the terms used in the present application should be understood as having the same meaning as the terms in the context of the present application and the related field, and should not be understood in an idealized or overly formal sense, except as explicitly defined in the present application.

[0031] The present application provides a preparation method of an organic copper chelate, comprising the following steps: Step (1): Mix amino acids, seaweed polysaccharides, trace element copper and optional catalyst in dry powder form, and then add a humidifying agent accounting for 2% to 5% of the total weight of the materials for humidification treatment. In this step, dry powder is first mixed and then a trace amount of humidifying agent (2%-5% by weight of the total material) is introduced. Without forming a solution system, this induces a localized solvation effect on the surface of the ligand (amino acid, polysaccharide) particles, thereby activating their surface active sites (such as amino, carboxyl, and hydroxyl groups). This achieves a shift from "physical mixing" to "chemical preparation." The trace amount of moisture acts as a "molecular lubricant," greatly promoting the transfer of protons and electrons in subsequent solid-state reactions, making it a key pretreatment step for enhancing the activity of complexation reactions. This method effectively avoids the problems of excessive wastewater and high energy consumption associated with traditional wet processes and is superior to the shortcomings of incomplete reactions in conventional dry processes.

[0032] Step (2): The humidified material is subjected to a pressing reaction under heating and pressurization conditions; By combining the activation energy provided by heating with a high pressure of 25 MPa to 35 MPa, the materials are forced into close contact, greatly increasing the probability of collisions between reactant molecules. Furthermore, the high pressure helps to disrupt the crystal water structure of the copper source (such as copper sulfate), and the released water molecules and heat create a localized "reaction microenvironment," further promoting the formation of coordination bonds. This achieves the simultaneous occurrence of chemical reaction (complexation) and physical process (granulation precursor). Compared to the complex process in existing technologies that requires multiple steps of hydrolysis, chelation, separation, and drying, this step integrates complexation and molding, significantly shortening the process flow, improving production efficiency, and fundamentally avoiding the introduction of solvents and subsequent processing.

[0033] Step (3): Granulate the product after the compression reaction.

[0034] In some preferred embodiments of the present invention, the amino acid in step (1) is selected from at least one of glycine, DL-methionine, L-methionine, L-lysine hydrochloride, L-lysine sulfate, L-threonine, L-tryptophan, L-valine, and L-glutamic acid. In these embodiments, the preferred amino acids (such as glycine, methionine, lysine, etc.) are small molecule amino acids with clearly defined coordinating atoms (N, O), and are known excellent metal chelating ligands, thereby ensuring the interaction with copper ions (Cu). 2+ This forms stable five- or six-membered ring chelates, thereby ensuring the bioavailability and chemical stability of the product base.

[0035] In some preferred embodiments of the present invention, the seaweed polysaccharide mentioned in step (1) is selected from at least one of *Ulva prolifera* polysaccharide, fucoidan oligosaccharide, *Ulva lactuca* polysaccharide, and fucoidan. In these embodiments, it is preferred that the seaweed polysaccharide molecules, such as *Ulva prolifera* polysaccharide and fucoidan oligosaccharide, contain a variety of potential coordinating groups such as hydroxyl, carboxyl, and sulfate groups; these groups, in their complementary and synergistic effects with amino acid ligands, can coordinate with copper ions to form mixed ligand complexes with more complex structures and higher stability, thereby improving the overall performance of the product.

[0036] In some preferred embodiments of the present invention, the trace element copper in step (1) is selected from at least one of copper sulfate, copper chloride, and basic copper chloride. In these embodiments, inorganic salts such as copper sulfate and copper chloride are preferably used. Under the conditions of pressure reaction, their water of crystallization is easily activated and released, providing the necessary local liquid microenvironment for the complexation reaction. These copper sources have high reactivity under the process conditions, which is a prerequisite for achieving efficient complexation.

[0037] In some preferred embodiments of the present invention, the catalyst in step (1) is an alkaline compound. Preferably, the alkaline compound is selected from at least one of sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, and potassium carbonate. In these embodiments, the preferred alkaline compound (such as NaOH or K2CO3) does not homogeneously catalyze under dry dispersion and compression conditions, but rather promotes the deprotonation (formation of -COO) of amino acid carboxyl groups (-COOH) by forming a local high-pH reaction microenvironment. - The latter is related to Cu 2+ A superior coordination form. This "solid-state alkali catalysis" mechanism avoids the use of liquid alkali catalysts, eliminating wastewater generation at the source of the process, and is an important manifestation of green environmental protection.

[0038] It is worth noting that, unlike traditional methods, this invention uses dry powder form of both the catalyst and raw materials for pre-wetting and mixing before entering the pressing system, instead of introducing the catalyst with an aqueous solution or liquid phase, thus avoiding the problems of uneven dispersion or low reaction efficiency caused by traditional methods.

[0039] In some preferred embodiments of the present invention, the humidifier in step (1) is deionized water. Using deionized water as a humidifier can effectively avoid the introduction of impurity ions.

[0040] In some preferred embodiments of the present invention, the molar ratio of amino acids, seaweed polysaccharides, and trace element copper in step (1) is (0.5-2):(0.5-2):(0.2-1), for example (0.5):(0.5):(0.2), (0.8):(1.0):(0.4), (1.2):(1.5):(0.6), (1.5):(1.8):(0.8), (2.0):(2.0):(1.0), etc., but is not limited to the listed values. Other unlisted values ​​within this range are also applicable. The present invention has found that under the "suppression linkage reaction" system of the present invention, the reactant molecules are forced to come into close contact under high pressure, resulting in extremely high reaction efficiency. At the same time, the local micro-humid environment and the released crystal water provide an ideal mass transfer medium for the reaction. Therefore, it is not necessary to drive the reaction equilibrium by using an excess of ligands. Thus, it can adapt to a wider range of molar ratios of amino acids, seaweed polysaccharides, and copper, and greatly reduces the residue of unreacted raw materials.

[0041] In some preferred embodiments of the present invention, the heating temperature in step (2) is 50°C to 60°C and the pressure is 25MPa to 35MPa; for example, the heating temperature is 50°C, 52°C, 54°C, 56°C, 58°C, 60°C, etc., and the pressure is 25MPa, 27MPa, 29MPa, 31MPa, 33MPa, 35MPa or any value between them.

[0042] The compression reaction described in step (2) is carried out under a vacuum of ≤1000 Pa.

[0043] It should be noted that traditional processes require relatively high temperatures (e.g., 65-75℃) to provide sufficient activation energy to overcome the reaction energy barrier. This invention, however, fundamentally alters the reaction pathway through a three-dimensional synergistic mechanism of "heating," "pressurization," and "vacuum": a pressure of 25MPa to 35MPa significantly increases the collision frequency and contact area of ​​reactant molecules, physically lowering the energy threshold required to initiate the reaction; controlling the vacuum level allows for the timely removal of reaction byproducts (such as water vapor), shifting the reaction equilibrium towards the products and thermodynamically driving the reaction. Thus, temperature control is no longer the sole driving factor. A lower temperature of only 50℃ to 60℃ is sufficient to efficiently complete the double complexation reaction with the synergistic assistance of high pressure and vacuum. The underlying scientific principle is that this process system replaces some of the role of thermal energy through physical means (pressure and vacuum).

[0044] In embodiments of the present invention, the humidification treatment, the pressing reaction, and the granulation step are performed continuously in the same equipment. Integrating the humidification treatment, pressing reaction, and granulation steps into the same equipment for continuous execution conforms to the continuous and automated concepts of modern process industries, minimizes losses, pollution, and energy consumption caused by material transfer, improves production efficiency and batch-to-batch consistency, and has good industrial prospects.

[0045] Furthermore, the present invention provides an organic copper chelate prepared by the above-described method for preparing organic copper chelates.

[0046] Furthermore, the present invention provides the application of the aforementioned organic copper chelate in feed additives.

[0047] The experimental results demonstrating the technical advantages of the present invention will be described below using examples and comparative examples.

[0048] In the following examples and comparative examples, unless otherwise specified, the experimental methods used are conventional methods, and the materials and reagents used are commercially available unless otherwise specified.

[0049] Example 1 A one-step preparation method for an amino acid-polysaccharide-copper organocopper chelate includes the following steps: In a 10L mixer, 0.5 mol of DL-methionine, 0.5 mol of fucoidan, 1.0 mol of copper sulfate, and 0.2 mol of sodium hydroxide were added, along with 5 wt.% deionized water, and mixed thoroughly for 10 minutes. The homogeneous mixture was then fed into a pressing reactor, heated to 50°C, pressurized to 25 MPa (vacuum ≤ 1000 Pa), and the rotation speed was set to 5 r / min. The mixture was then dry-pressed for 20 minutes. The reacted material was discharged using a screw, with the discharge port being a granulation mold flange, producing uniform 0.3 mm granules. After sieving, 20-60 mesh granules were obtained to yield glucosamine copper.

[0050] Example 2 A one-step preparation method for an amino acid-polysaccharide-copper organocopper chelate includes the following steps: In a 10L mixer, 1.0 mol of DL-methionine, 1.0 mol of fucoidan, 1.0 mol of copper sulfate, and 0.2 mol of sodium hydroxide were added, along with 5 wt.% deionized water, and mixed thoroughly for 10 minutes. The homogeneous mixture was then fed into a pressing reactor, heated to 50°C, pressurized to 25 MPa (vacuum ≤ 1000 Pa), and the rotation speed was set to 5 r / min. The mixture was then dry-pressed for 20 minutes. The reacted material was discharged using a screw, with the discharge port being a granulation mold flange, producing uniform 0.3 mm granules. After sieving, 20-60 mesh granules were obtained to yield glucosamine copper.

[0051] Example 3 A one-step preparation method for an amino acid-polysaccharide-copper organocopper chelate includes the following steps: In a 10L mixer, 1.5 mol of DL-methionine, 1.5 mol of fucoidan, 1.0 mol of copper sulfate, and 0.2 mol of sodium hydroxide were added, along with 5 wt.% deionized water, and mixed thoroughly for 10 minutes. The homogeneous mixture was then fed into a pressing reactor, heated to 50°C, pressurized to 25 MPa (vacuum ≤ 1000 Pa), and the rotation speed was set to 5 r / min. The mixture was then dry-pressed for 20 minutes. The reacted material was discharged using a screw, with the discharge port being a granulation mold flange, producing uniform 0.3 mm granules. After sieving, 20-60 mesh granules were obtained to yield glucosamine copper.

[0052] Example 4 A one-step preparation method for an amino acid-polysaccharide-copper organocopper chelate includes the following steps: In a 10L mixer, 2.0 mol of DL-methionine, 2.0 mol of fucoidan, 1.0 mol of copper sulfate, and 0.2 mol of sodium hydroxide were added, along with 5 wt.% deionized water, and mixed thoroughly for 10 minutes. The homogeneous mixture was then fed into a pressing reactor, heated to 50°C, pressurized to 25 MPa (vacuum ≤ 1000 Pa), and the rotation speed was set to 5 r / min. The mixture was then dry-pressed for 20 minutes. The reacted material was discharged using a screw, with the discharge port being a granulation mold flange, producing uniform 0.3 mm granules. After sieving, 20-60 mesh granules were obtained to yield glucosamine copper.

[0053] Comparative Example 1 This comparative example did not contain methionine or seaweed polysaccharides.

[0054] Comparative Example 2 A one-step preparation method for an amino acid-polysaccharide-copper organocopper chelate includes the following steps: In a 10L mixer, 0.2 mol of DL-methionine, 0.2 mol of fucoidan, 1.0 mol of copper sulfate, and 0.2 mol of sodium hydroxide were added, along with 5 wt.% deionized water, and mixed thoroughly for 10 minutes. The homogeneous mixture was then fed into a pressing reactor, heated to 50°C, pressurized to 25 MPa (vacuum ≤ 1000 Pa), and the rotation speed was set to 5 r / min. The mixture was then dry-pressed for 20 minutes. The reacted material was discharged using a screw, with the discharge port being a granulation mold flange, producing uniform 0.3 mm granules. After sieving, 20-60 mesh granules were obtained to yield glucosamine copper.

[0055] Comparative Example 3 A method for preparing an amino acid-polysaccharide-copper organocopper chelate includes the following steps: The first dry complexation reaction was carried out in a mixing reactor equipped with paddles, a heating jacket, and a vacuum system. 2.0 mol of DL-methionine, 0.1 mol of sodium hydroxide, and 25 wt.% water (based on the total weight of the materials) were added, and the mixture was stirred at 70°C for 25 min. Then, 1 mol of copper sulfate was added, the reactor was covered, and a vacuum of 800 Pa was applied to the mixing reactor. The reaction was carried out under vacuum for 30 min. After the reaction, samples were taken to determine the free DL-methionine content. If the DL-methionine content was higher than 1%, the reaction was continued until it fell below 1% to reach the endpoint of the first complexation reaction.

[0056] In the second dry complexation reaction, after the first complexation reaction reaches its endpoint, open the lid and add 2 mol of fucoidan and 0.1 mol of sodium hydroxide. After adding, close the lid, evacuate the mixing reactor to 800 Pa, maintain the temperature at 65°C, and continue the reaction for 30 minutes. At the end of the reaction, the material should be dry and loose, not moist and sticky. Sampling and determining the free copper ion content; if the free copper ion content is less than 1%, the second complexation reaction has reached its endpoint.

[0057] The material after the dry granulation reaction is completed is fed into a roller press and pressurized to 25 MPa. The material is rolled into dense blocks and cooled in a material silo with a cooling jacket at 2℃~5℃ before entering a crusher for crushing. After screening, 20-60 mesh product particles are obtained to obtain glucosamine copper.

[0058] Comparative Example 4 The difference between this comparative example and Example 4 is that step (2) is performed under normal pressure.

[0059] Comparative Example 5 The difference between this comparative example and Example 4 is that the heating temperature in step (2) is 65°C.

[0060] Comparative Example 6 The difference between this comparative example and Example 4 is that the deionized water added in step (1) accounts for 10 wt.% of the total weight of the material.

[0061] Test Example The complexation rate of glucosamine copper was determined according to the requirements of the organic solvent extraction method.

[0062] Principle: Organic trace elements are insoluble in methanol, while free metal ions are soluble in methanol. Taking advantage of this property, organic trace elements are extracted with methanol, and the total trace element content in the sample and the trace element content (in complexed state) in the precipitate are determined separately. The complexation (chelation) rate of each trace element is then calculated.

[0063] Analytical Procedure: Weigh approximately 0.5 g (accurate to 0.0002 g) of the sample into a 150 mL iodine flask, add 20 mL of anhydrous methanol, shake for 10 min, and filter using quantitative filter paper. Rinse the iodine flask three times with 10 mL of anhydrous methanol each time. Transfer the precipitate and filter paper to a crucible and char it over a low flame on a temperature-controlled resistance furnace with an asbestos mesh. Then, proceed according to GB / T 13885-2017 to determine the copper content in the precipitate (complexed state). Copper content in the complexed state / total copper content = complexation rate (%).

[0064] Table 1

[0065] As shown in the table above, Examples 1-4 had sufficient organic ligands to ensure complete reaction, resulting in a complexation rate of over 95% for the glucosamine copper product. Comparative Example 1 did not react, meaning no organic ligands were produced. Comparative Example 2 had insufficient organic ligands, leading to incomplete reaction and a complexation rate of only 40%. Comparative Example 3 used a two-step dry complexation method and added a large amount of water, resulting in a final glucosamine copper product with a complexation rate of only 88%. Comparative Example 4 used atmospheric pressure conditions, leading to incomplete reaction and a complexation rate of only 40%. Comparative Example 5 was heated to 65°C, causing some methionine ligands to oxidize and decompose, resulting in a complexation rate of 85%. Comparative Example 6 added 10 wt.% deionized water, increasing material viscosity, producing agglomerated clumps, and resulting in uneven reaction and a complexation rate of 80%.

[0066] In summary, compared with the prior art, this invention proposes an amino acid-polysaccharide complex (chelate) preparation process that combines the advantages of amino acid complexes (chelates) and polysaccharide complexes (chelates). It ingeniously integrates "dual complexation reaction" and "granulation molding" in a continuous process, without generating wastewater and reducing product reaction time. It also eliminates the need for drying, thereby improving production efficiency. Furthermore, the absence of organic solvents greatly enhances production safety and eliminates the problem of disposing of waste mother liquor.

[0067] Furthermore, those skilled in the art should understand that although many problems exist in the prior art, each embodiment or technical solution of the present invention can be improved in only one or a few aspects, without necessarily solving all the technical problems listed in the prior art or the background art simultaneously. Those skilled in the art should understand that any content not mentioned in a claim should not be construed as a limitation on that claim.

[0068] Although this document frequently uses terms such as amino acids, seaweed polysaccharides, trace element copper, catalysts, humectants, and alkaline compounds, the possibility of using other terms is not excluded. These terms are used merely for the convenience of describing and explaining the essence of the invention; interpreting them as any kind of additional limitation would contradict the spirit of the invention. The terms "first," "second," etc. (if present) in the specification and claims of the embodiments of the invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing an organic copper chelate, characterized in that, comprising the following steps: Step (1), mixing amino acid, seaweed polysaccharide, trace element copper and optional catalyst in dry powder form, and then adding 2% to 5% of the total weight of the material wetting agent for wetting treatment; Step (2), the material after wetting treatment is subjected to compression reaction under heating and pressurization conditions; Step (3), the product after compression reaction is granulated.

2. The method for preparing an organic copper chelate according to claim 1, characterized in that, in step (1), the amino acid is selected from at least one of glycine, DL-methionine, L-methionine, L-lysine hydrochloride, L-lysine sulfate, L-threonine, L-tryptophan, L-valine, and L-glutamic acid.

3. The method for preparing an organic copper chelate according to claim 1, characterized in that, in step (1), the seaweed polysaccharide is selected from at least one of Enteromorpha polysaccharide, brown algal oligosaccharide, Ulva polysaccharide, and brown algal polysaccharide.

4. The method for preparing an organic copper chelate according to claim 1, characterized in that, in step (1), the trace element copper is selected from at least one of copper sulfate, copper chloride, and basic copper chloride.

5. The method for preparing an organic copper chelate according to claim 1, characterized in that, in step (1), the catalyst is a basic compound, preferably, the basic compound is selected from at least one of sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, and potassium carbonate; and / or in step (1), the wetting agent is deionized water.

6. The method for preparing an organic copper chelate according to claim 1, characterized in that, in step (1), the molar ratio of the amino acid, seaweed polysaccharide, and trace element copper is (0.5-2):(0.5-2):(0.2-1).

7. The method for preparing an organic copper chelate according to claim 1, characterized in that, in step (2), the heating temperature is 50°C to 60°C, and the pressure is 25 MPa to 35 MPa; and / or in step (2), the compression reaction is carried out under a vacuum degree of ≤1000 Pa.

8. The method for preparing an organic copper chelate according to claim 1, characterized in that, the wetting treatment, the compression reaction, and the granulation step are continuously performed in the same equipment.

9. An organic copper chelate prepared by the method according to any one of claims 1 to 8.

10. Use of the organic copper chelate according to claim 9 in a feed additive. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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