阅读说明：本技术 球形脲醛缩合物肥料 (Spherical urea formaldehyde condensate fertilizer ) 是由 拉贾马莱斯沃拉玛·科里佩利 萨蒂什·布尔拉 拉达·阿查纳特 沙米克·古普塔 于 2019-07-23 设计创作，主要内容包括：含有脲醛缩合物的肥料。所述肥料可以是球形的并且可以使用造粒和/或球化技术形成,任选地,所述肥料可以是球化的挤出肥料。(A fertilizer containing a urea formaldehyde condensate. The fertilizer may be spherical and may be formed using granulation and/or spheronization techniques, optionally the fertilizer may be a spheronized extruded fertilizer.)

1. A method for making spherical fertilizer particles comprising a urea-formaldehyde condensate, the method comprising:

(a) combining a urea-formaldehyde condensate with water to form a mixture;

(b) optionally extruding the mixture;

(c) forming spheres from the mixture; and

(d) drying the spheres to form spherical urea formaldehyde condensate fertilizer particles.

2. The method of claim 1, wherein the mixture is extruded through a perforated die prior to forming the spheres.

3. The process according to any one of claims 1 to 2, wherein the mixture is extruded through an extruder operated at a speed of 20rpm to 300rpm and a pressure of 1 bar to 50 bar, preferably a speed of 75rpm to 125rpm and a pressure of 1 bar to 3 bar.

4. A process according to any one of claims 1 to 3, wherein the spheres are formed with a spheronizer and/or a granulator.

5. The process according to claim 4, wherein the spheronizer is operated with an air flow at a disc speed of 1500rpm to 5000rpm and a pressure of 0.5 bar to 10 bar, preferably at a disc speed of 2000rpm to 3000rpm and a pressure of 1 bar to 2 bar.

6. A process according to any one of claims 4 to 5, in which the granulator is operated at a rotational speed of from 500RPM to 10RPM, preferably from 100RPM to 10RPM, and at a gas stream at a pressure of from 0.1 bar to 10 bar, preferably from 0.1 bar to 3 bar, and a temperature of from 40 ℃ to 100 ℃, preferably from 55 ℃ to 85 ℃.

7. A method according to any one of claims 1 to 6, wherein the spheres have an average diameter of from 1mm to 3.5mm, preferably from 1.5mm to 2.5 mm.

8. The method of any one of claims 1 to 7, wherein the mixture comprises from 15 to 30 wt.% water.

9. The method of any one of claims 1 to 8, wherein the mixture further comprises one or more than one flow promoter, binder, or a combination thereof.

10. The method of claim 9, wherein the mixture comprises from 0.01 wt% to 10 wt% of one or more than one of a flow promoter, a binder, or a combination thereof.

11. A method according to any one of claims 9 to 10, wherein the flow promoter is one or more of bleached wheat flour, microcrystalline silicon dioxide, chitosan, natural gums such as agar, guar gum, clays such as bentonite, cellulose derivatives such as carboxymethyl cellulose, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose and hydroxypropylmethyl cellulose (HPMC).

12. The method according to any one of claims 9 to 11, wherein the binder is one or more than one of bleached wheat flour, guar gum, calcium lignosulfonate, gelatin, seaweed extract, plaster of paris, flour, starch, cellulose, gluten, colloidal silica, kaolin, bentonite, polyethylene glycol (PEG), polycaprolactone and low molecular weight polyvinyl acetate.

13. The method of any of claims 1 through 12 wherein the urea-formaldehyde condensate comprises at least one urea-C₁-C₄Aldehyde condensates.

14. The method of any of claims 1 through 13 wherein the urea-formaldehyde condensate comprises at least one urea-C₂-C₄Aldehyde condensates.

15. The method of any one of claims 1 to 14, wherein the urea-formaldehyde condensate comprises methylene urea-isobutylidene diurea (MU-IBDU) or a derivative thereof.

16. The method of any one of claims 1 to 15, wherein the spherical urea formaldehyde condensate fertilizer particles have an average crush strength of greater than 1.3 kgf/particle, greater than 1.6 kgf/particle, greater than 1.8 kgf/particle, greater than 2.0 kgf/particle, or from 1.3 kgf/particle to 3.5 kgf/particle.

17. A fertilizer composition comprising spherical urea-C1-C4 aldehyde condensate fertilizer granules having an average diameter of 1mm to 3.5mm and an average crush strength of greater than 1.3 kgf/granule, greater than 1.6 kgf/granule or greater than 1.8 kgf/granule.

18. The fertilizer composition of claim 17, having an average diameter of from 1.5mm to 2.5mm and a crush strength of from 1.3 kgf/granule to 3.5 kgf/granule.

19. According to any one of claims 17 and 18The fertilizer composition of, wherein urea-C₁-C₄The aldehyde condensate includes methylene urea-isobutylidene diurea (MU-IBDU) or its derivatives.

20. The fertilizer composition of any one of claims 17-19, wherein the composition is a fertilizer mixture or a compound fertilizer.

21. The fertilizer composition of any one of claims 17-20, wherein the composition further comprises a micronutrient.

22. A method of fertilizing a fertilizer comprising applying the fertilizer composition of any one of claims 17 to 21, or a combination thereof, to a portion of soil, a crop, or soil and a crop.

Background

A. Field of the invention

The present invention relates generally to fertilizers comprising urea-formaldehyde condensates. The fertilizer may be spherical and may be formed using granulation (e.g., pan granulation and/or drum granulation) or spheronization techniques, and the spheronized fertilizer may optionally be extruded.

B. Description of the related Art

To increase crop yields and meet the growing demand of an increasing population, more fertilizers are used in agriculture. Nitrogen containing fertilizers are used to support healthy plant growth and photosynthesis. Urea (CH)₄N₂O) is a nitrogen-containing compound and is widely used as a nitrogen source in fertilizers. However, nitrogen from urea is lost very quickly due to its rapid hydrolysis and nitrification in the soil by soil bacteria.

Urea-formaldehyde condensates have been used as a solution to the problem of rapid loss of nitrogen from urea. Short-chain urea-formaldehyde condensates and polymers are particularly valuable for use in fertilizers because of their water-soluble nitrogen content. However, there are certain difficulties in using these condensates. For example, it has been found that granular slow release fertilizer products often have physical and chemical performance disadvantages, such as poor hardness. Similarly, slow release fertilizers such as isobutylidene diurea (IBDU) also result in granules having poor hardness (e.g., a breaking strength of 0.8 kgf/granule or less than 0.8 kgf/granule) when granulated. These particles can have poor nutrient use efficiency because they readily decompose into powders and inorganic nitrogen (see Plant nutrition for stable food production and environment,639-640, 1997). Furthermore, the urea-formaldehyde condensate granular products have limitations in bulk compost due mainly to the low particle hardness and small particle size (US 2009/0165515). Thus, slow release fertilizers such as urea formaldehyde condensates can be friable and dusty. These problems limit their use in agricultural applications and bulk blend fertilizers.

Some have attempted to solve these problems by combining slow release fertilizers with binders (Plant nutrition for sustainable food production and environment,639-640,1997; US 2009/0165515; US 5039328; WO 2017/013573; US 2016/0340265; US 2016/0060182; and EP 1174402). However, the added binder may not provide nutritional value to the fertilizer, may increase cost and/or manufacturing complexity, and may undesirably increase the weight and volume of the fertilizer. Some have attempted to control catalytic or chemical reactions to produce sized fertilizer particles with desired crush strength (US 2003/0154754). However, these processes are complex and most of the material coming out of the reaction vessel cannot be used as fertilizer, requiring reintroduction into the production process. These processes add additional complexity, may produce products that do not require reintroduction in only low yields, and increase production costs.

Therefore, there is a need to develop slow release fertilizers having improved physical properties and methods of developing the fertilizers.

Disclosure of Invention

The present inventors have discovered a solution to at least some of the above-mentioned problems associated with slow release fertilizers. This solution is based on providing a fertilizer, for example a spherical urea formaldehyde condensate. The spherical urea formaldehyde condensate fertilizer of the present invention has improved hardness and use efficiency. These fertilizers also have the property of preventing powdering. These properties combine the fertilizer of the present invention with other fertilizers or fertilizer ingredients to form a mixed fertilizer composition. Mixing may occur after the spherical fertilizer particles are formed. In this manner, spherical fertilizer granules can be added to other fertilizers, thereby creating customized fertilizer mixtures and/or products to suit the fertilizer needs of a particular application. These properties also allow for increased nutrient delivery and slow nutrient release.

The fertilizer of the present invention may be formed into spheres by granulation (e.g., pan granulation and/or drum granulation) or spheronization techniques. The spheronization technique may include the use of a spheronizer and may further include extruding the fertilizer prior to the use of the spheronizer. Granulation or spheronization may be performed after the chemical reaction that produces the fertilizer ingredients is complete and before or after drying the fertilizer. Another advantage of spheronization is that the spheronization process can produce particles of consistent size and can also reduce the need for recycling of particles that do not meet size requirements. This reduced cycling may enable a more cost effective process that is commercially scalable.

In some aspects of the invention, spherical urea-C is disclosed₁To C₄Aldehyde condensate particles. In some preferred cases, the spherical urea-formaldehyde condensate particles are C₂-C₄Aldehyde condensate particles. In some preferred cases, the spherical urea-formaldehyde condensate particles are C₁Aldehyde condensate and_C4aldehyde condensate mixture. In some preferred cases, the spherical urea-formaldehyde condensate particles are C₁Aldehydes and C₄Aldehyde condensate mixture. The particles may be of any size. In some cases, the particles have an average diameter of 1mm to 4mm, 1mm to 3.5mm, 1mm to 3mm, 1.5mm to 2.5mm, 2mm to 3.5mm, or any range therebetween, including 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3.0mm, 3.5mm, 4mm, and any ranges and subranges therebetween. In some cases, the crush strength of the particles can be greater than that of non-spherical urea-C₁To C₄Aldehyde condensate particles. In some cases, the average crush strength is greater than 1.3 kgf/particle, greater than 1.6 kgf/particle, greater than 1.8 kgf/particle, greater than 1.9 kgf/particle, greater than 2.0 kgf/particle, 1.3 kgf/particle to 3.5 kgf/particle, 1.6 kgf/particle to 4 kgf/particle, 1.6 kgf/particle to 3.5 kgf/particle, 1.8 kgf/particle to 3.5 kgf/particle, 1.9 kgf/particle to 3.5 kgf/particle, or any range therebetween. In some cases, the average crush strength is 1.3 kgf/particle, 1.4 kgf/particle, 1.5 kgf/particle, 1.6 kgf/particle, 1.7 kgf/particle, 1.8 kgf/particle, 1.9 kgf/particle, 2.0 kgf/particle, 2.1 kgf/particle, 2.2 kgf/particle, 2.3 kgf/particle, 2.4 kgf/particle, 2.5 kgf/particle, 2.6 kgf/particle, 2.7 kgf/particle, 2.8 kgf/particle, 2.9 kgf/particle, 3.0 kgf/particle, 3.1 kgf/particle, 3.2 kgf/particle, 3.3 kgf/particle, 3.4 kgf/particle, 3.5 kgf/particle, or greater than 3.5 kgf/particle, including all ranges and subranges therebetween.

C of spherical Urea-Formaldehyde condensate₁To C₄The aldehyde can be any C₁To C₄An aldehyde, a derivative thereof, or a combination thereof. In some cases, C₁To C₄The aldehyde may be formaldehyde, butyraldehyde, isobutyraldehyde, crotonaldehyde, or any combination thereof. Formaldehyde can be in various forms, for example, its aldehyde form (CH)₂O), its hydrated form (methanediol) and its paraformaldehyde form. In some particular cases, the formaldehyde may be urea formaldehyde concentrate-85 or formalin containing 37% to 65% formaldehyde. In some cases, the urea-formaldehyde condensate includes at least one isobutylidene diurea derivative and at least one methylene urea oligomer. In some cases, the urea-formaldehyde condensate includes methylene urea-isobutylidene diurea (MU-IBDU) or derivatives thereof. In some cases, the urea-formaldehyde condensate includes isobutylidene diurea, mono (ureidomethylene) isobutylidene diurea, bis (ureidomethylene) isobutylidene diurea, and at least two, at least three, or all four methylene urea oligomers selected from the group consisting of methylene diurea, dimethylene triurea, trimethylene tetraurea, and tetramethylene pentaurea. In some preferred cases, C is used₂-C₄An aldehyde.

The spherical urea-formaldehyde condensate particles may contain the urea-formaldehyde condensate alone or may contain one or more than one additional ingredient. Additional ingredients that may be included in the particles include flow promoters, binders, pH adjusters or buffers, or combinations thereof. In some cases, the particles do not comprise a flow promoter, a binder, or a pH adjuster or buffer. When the urea-formaldehyde condensate is mixed with water to form a mixture, additional ingredients may be added to the particles. The particles may contain any amount of additional ingredients, for example, 0.001 wt% to 10 wt%, 0.001 wt% to 9 wt%, 0.001 wt% to 8 wt%, 0.001 wt% to 7 wt%, 0.01 wt% to 10 wt%, 0.01 wt% to 9 wt%, 0.01 wt% to 8 wt%, 0.01 wt% to 7 wt%, or any range or value therebetween. In some cases, the particles can contain 0.001 wt%, 0.002 wt%, 0.003 wt%, 0.004 wt%, 0.005 wt%, 0.006 wt%, 0.007 wt%, 0.008 wt%, 0.009 wt%, 0.01 wt%, 0.02 wt%, 0.03 wt%, 0.04 wt%, 0.05 wt%, 0.06 wt%, 0.07 wt%, 0.08 wt%, 0.09 wt%, 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, or 10 wt% of an additional ingredient. In some cases, the flow promoter in the granules is one or more than one of bleached wheat flour, microcrystalline silicon dioxide, chitosan, natural gums such as agar, guar gum, clays such as bentonite, cellulose derivatives such as carboxymethyl cellulose, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose and hydroxypropyl methyl cellulose (HPMC). In some cases, the binder is one or more than one of bleached wheat flour, guar gum, calcium lignosulfonate, gelatin, seaweed extract, plaster of paris, flour, starch, cellulose, gluten, colloidal silica, kaolin, bentonite, polyethylene glycol (PEG), polycaprolactone, low molecular weight polyvinyl acetate, and/or a 60 wt.% urea solution. In some cases, the granules do not contain calcium nitrate tetrahydrate, or contain less than 0.4% by weight calcium nitrate tetrahydrate.

The spherical urea-formaldehyde condensates herein or one or more than one chemical species therein can be formulated as a fertilizer. In some cases, the condensate is formulated into a slow release fertilizer. In some cases, the condensates are formulated into specialty fertilizers. The methods disclosed herein may further include the step of mixing the condensate or one or more chemicals therein with other fertilizers, secondary nutrients, trace elements, plant protection agents, fillers, and/or with other fertilizer ingredients to form a blended fertilizer.

In some aspects of the invention, fertilizer compositions are disclosed. The fertilizer composition may comprise a plurality of spherical acetal condensate fertilizer particles of the present invention. In certain instances, the fertilizer composition may also be a mixture of a non-urea formaldehyde condensate fertilizer and a plurality of the spherical urea formaldehyde condensate fertilizer particles disclosed herein. The fertilizer composition may comprise any concentration of the spherical urea formaldehyde condensate fertilizer. The spherical urea formaldehyde condensate fertilizer may be a source of the entire amount of nitrogen in the fertilizer composition.

Also disclosed in the context of the present invention are processes and methods for making and/or using the spherical urea-formaldehyde condensates and fertilizer compositions disclosed herein. Spherical particles can be produced by the following steps: combining a urea-formaldehyde condensate with water to form a mixture; optionally extruding the mixture; forming spheres from the mixture or extrudate; and drying the spheres to form spherical urea-formaldehyde condensate particles. In some cases, the mixture contains 10 to 40 weight percent water, 10 to 30 weight percent water, 10 to 20 weight percent water, 15 to 40 weight percent water, 15 to 30 weight percent water, 15 to 20 weight percent water, 20 to 40 weight percent water, 20 to 30 weight percent water, 30 to 40 weight percent water, or any value and range therebetween. In some cases, the mixture contains 10, 15, 20, 25, 30, 35, or 40 weight percent water.

In some cases, the urea-formaldehyde condensate is first extruded before forming the spheres. The extrusion temperature may be above the melting point of one or more than one binder used in the spherical urea formaldehyde condensate fertilizer. The temperature may be below the temperature at which the fertilizer degrades. The temperature may be below the melting temperature of the urea-formaldehyde condensate or urea. In some cases, the extrusion temperature may be less than 50 ℃, less than 40 ℃, less than 35 ℃, preferably from 20 ℃ to 50 ℃, from 20 ℃ to 40 ℃, more preferably from 20 ℃ to 35 ℃.

The extrusion process may be carried out in any extruder. In some cases, the extruder is a single screw extruder, a twin screw extruder, a triple screw extruder, or an extruder with more than three screws. In some cases, the extruder is capable of rotating at a rate of 20rpm to 300rpm, preferably about 40rpm to 200rpm, more preferably about 60rpm to 120 rpm. In some cases, the pressure of the extruder is from 1 bar to 50 bar, preferably from 15 bar to 45 bar, more preferably from 25 bar to 35 bar.

The extruded urea-formaldehyde condensate may be cut or passed through a die prior to forming the spheres. In some cases, the mold may be porous.

In some cases, the urea-formaldehyde condensate particles form spheres through a spheroidization process. The process may include using a sphering machine. The process may be performed in any sphering machine. In some cases, the pelletizer is a disk pelletizer. In some cases, the disc is operated at a disc speed of greater than 1000RPM, greater than 1500RPM, 1500RPM to 5000RPM, 1500RPM to 3500RPM, 2000RPM to 3000RPM, or any range therebetween. In some cases, the spherizer is operated with a gas flow at a pressure of 0.1 bar to 10 bar, 0.5 bar to 2 bar, 0.5 bar to 1 bar, 0.1 bar to 3 bar, 0.1 bar to 2 bar, 0.1 bar to 1 bar, 0.3 bar to 0.7 bar, or any range therebetween. The spheronization process may be performed for any time, such as 1 minute to 15 minutes, 1 minute to 10 minutes, 2 minutes to 15 minutes, 2 minutes to 10 minutes, or any range therebetween.

In some cases, the urea-formaldehyde condensate particles are formed into spheres by granulation (e.g., pan granulation and/or drum granulation) techniques or in combination with, for example, spheroidization techniques using a spheroidizer. Granulation may be carried out in any suitable granulator. In some cases, granulation is performed using a powdered urea-formaldehyde condensate and water. In some cases, the pelletizer is operated at a rotational speed of less than 500RPM, less than 400RPM, less than 300RPM, less than 200RPM, less than 100RPM, less than 90RPM, less than 80RPM, less than 70RPM, less than 60RPM, less than 50RPM, less than 40RPM, less than 30RPM, less than 20RPM, less than 10RPM, or any range of RPM therebetween. In some cases, the granulator is operated at a pressure of 0.1 to 10 bar, 0.5 to 2 bar, 0.5 to 1 bar, 0.1 to 3 bar, 0.1 to 2 bar, 0.1 to 1 bar, 0.3 to 0.7 bar or any range therebetween and a gas flow of 40 ℃, 50 ℃, 60 ℃, 70 ℃, 80 ℃, 90 ℃, 100 ℃ or any temperature or range therein or therebetween. The granulation process may be performed for any time, such as 1 minute to 15 minutes, 1 minute to 10 minutes, 2 minutes to 15 minutes, 2 minutes to 10 minutes or any range or time therebetween.

In some cases, the particles are dried before, during, and/or after spheronization and/or granulation. In some cases, the particles can be dried to have a water content of less than 1 wt.%, less than 0.9 wt.%, less than 0.8 wt.%, less than 0.7 wt.%, less than 0.6 wt.%, less than 0.5 wt.%, less than 0.4 wt.%, less than 0.3 wt.%, less than 0.2 wt.%, less than 0.1 wt.%, or 0 wt.%, or any range or amount therein or therebetween. The particles may be dried at 40 ℃, 50 ℃, 60 ℃, 70 ℃, 80 ℃, 90 ℃ or 100 ℃, or any temperature or range therebetween.

The process may further include combining the spherical urea-formaldehyde condensate fertilizer with a non-urea-formaldehyde condensate fertilizer to form a blended fertilizer. In some cases, the non-urea formaldehyde condensate fertilizer is not combined with the spherical condensate fertilizer. The spherical urea-formaldehyde condensate fertilizer and the non-urea-formaldehyde condensate fertilizer may be combined in any ratio. In some cases, the non-urea formaldehyde condensate fertilizer is not combined with the spherical urea formaldehyde condensate fertilizer. In some cases, the mixed fertilizer contains a spherical urea-formaldehyde condensate fertilizer and a non-urea-formaldehyde condensate fertilizer in a ratio of 1: 100 to 100: 1, preferably 1: 10 to 10: 1, more preferably 1: 4 to 4: 1 or any range therebetween.

The spherical urea formaldehyde condensate fertilizer of the present invention, the fertilizer composition of the present invention, and the fertilizer composition prepared by the method of the present invention can be used for fertilizing by applying to at least one of soil, an organism carrier, and/or an organism. In some cases, the spherical urea formaldehyde condensate fertilizer of the present invention, the fertilizer composition of the present invention, and the fertilizer composition prepared by the method of the present invention are combined with a liquid carrier, a liquid solvent, or a combination thereof prior to application to soil, an organism carrier, or an organism.

The term "fertilizer" is defined as a material that is applied to soil or plant tissue to provide one or more plant nutrients necessary or beneficial for plant growth, and/or a stimulant or enhancer for increasing or promoting plant growth. Non-limiting examples of fertilizers include materials having one or more than one urea-formaldehyde condensate of the present invention, urea, ammonium nitrate, calcium ammonium nitrate, one or more than one calcium superphosphate, a binary NP fertilizer, a binary NK fertilizer, a binary PK fertilizer, an NPK fertilizer, molybdenum, zinc, copper, boron, cobalt and/or iron. In some aspects, fertilizers include agents that enhance plant growth and/or enhance the ability of a plant to obtain fertilizer benefits, such as, but not limited to, bio-stimulants.

The following includes definitions of various terms and expressions used throughout this specification.

“C₁To C₄Aldehyde "and/or" C₂To C₄The aldehyde "may be a linear or branched aldehyde having 1 to 4 carbon atoms or 2 to 4 carbon atoms, a saturated or unsaturated aldehyde, a substituted aldehyde, or the like, respectively. Non-limiting examples include formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, isobutyraldehyde, and crotonaldehyde. In some specific cases, C₂To C₄Aldehydes are used to produce the urea-formaldehyde condensates of this invention.

The term "short chain" methylene ureas can include methylene ureas containing from 1 to 5 urea units.

The term "particle" may include solid materials. The particles may have a variety of different shapes, non-limiting examples of which include spherical, disk-shaped, elliptical, rod-shaped, oblong, or random shapes. The terms "particle" and "granule" are interchangeable in this application.

The term "particulate" or "powder" may include a plurality of particles.

The term "biodegradable" is defined as capable of being degraded by naturally occurring organisms or by natural environmental conditions such as exposure to water, rain, sunlight, heat and cold, and the like. Naturally occurring organisms may include bacteria, fungi, plants, insects, animals, mammals, and/or humans.

The term "reduce" or variations of this term includes any measurable reduction or complete reduction in order to achieve a desired result.

The term "effective" or variations of that term is sufficient to achieve a desired, expected, or intended result.

The terms "about", "about" and "substantially" are defined as being approximately as understood by one of ordinary skill in the art. In one non-limiting example, the term is defined as being within 10%, preferably within 5%, more preferably within 1%, and most preferably within 0.5%.

The terms "weight percent", "volume percent" or "mole percent" refer to the weight percent, volume percent or mole percent of a component, respectively, based on the total weight, volume or total moles of the material comprising the component. In one non-limiting embodiment, 10 grams of a component in 100 grams of a material comprising the component is 10 weight percent of the component.

When used in the claims and/or the specification with any one of the terms "comprising," including, "" containing, "or" having, "an element may be preceded by the word" a "or" an "without the use of a quantitative term, but it also conforms to the meaning of" one or more, "" at least one, "and" one or more than one.

The words "comprising," "having," "including," or "containing" are inclusive or open-ended and do not exclude additional, unrecited elements or method steps.

The methods and compositions of the present invention may "comprise," "consist essentially of," or "consist of" the particular ingredients, components, compositions, etc. disclosed throughout this specification. With respect to the transitional expression "consisting essentially of … …," in one non-limiting aspect, a fundamental and novel feature of the spherical urea-formaldehyde condensate particles of the present invention is the spherical shape of these particles and their improved crush strength.

Other objects, features and advantages of the present invention will become apparent from the following drawings, detailed description and examples. It should be understood, however, that the drawings, detailed description and examples, while indicating specific embodiments of the present invention, are given by way of illustration only and not by way of limitation. In addition, it is contemplated that variations, combinations, and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

Drawings

Advantages of the present invention will become apparent to those skilled in the art from the following detailed description, taken in conjunction with the accompanying drawings. The invention is susceptible to various modifications and alternative forms, specific embodiments thereof being shown by way of example in the drawings. The drawings may not be to scale.

FIG. 1 shows a non-limiting representation of an embodiment of a spherical urea formaldehyde condensate fertilizer.

Fig. 2 depicts an embodiment of a method of producing a spherical urea formaldehyde condensate fertilizer.

Fig. 3 depicts an embodiment of a method of producing a blended fertilizer.

Fig. 4 depicts an embodiment of a method of producing a spherical urea formaldehyde condensate fertilizer.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and may herein be described in detail. The drawings may not be to scale.

Detailed Description

The spherical urea formaldehyde condensate fertilizer of the present invention provides a superior solution to at least some of the problems associated with urea formaldehyde condensate fertilizers. The spherical urea formaldehyde condensate fertilizer may be pelletized and/or spheroidized to form spheres and may optionally be extruded prior to spheroidization. The granulation and/or spheronization may be carried out after completion of the chemical reaction that produces the urea-formaldehyde condensate. The presence of the optional binder and/or flow promoter in the spherical urea formaldehyde condensate fertilizer may facilitate the production of the spherical urea formaldehyde condensate fertilizer. The spherical urea formaldehyde condensate fertilizer can be of uniform size. The blended fertilizers of the present invention may contain a variety of spherical urea formaldehyde condensate fertilizers in combination with other fertilizers or fertilizer ingredients.

These and other non-limiting aspects of the invention are discussed in further detail in the following sections.

A. Spherical urea formaldehyde condensate fertilizer

Figure 1 symbolically depicts an illustrative cross-sectional view of an embodiment of a spherical urea-formaldehyde condensate fertilizer of the present invention. In the embodiment shown, the spherical urea-formaldehyde condensate fertilizer 100 includes an optional binder and/or flow promoter 101 and a urea-formaldehyde condensate 102. The spherical urea formaldehyde condensate fertilizer 200 comprises a urea formaldehyde condensate 102. The spherical urea formaldehyde condensate fertilizers 100 and 200 have a circular cross-section. The spherical urea formaldehyde condensate fertilizers 100 and 200 may also include other ingredients such as micronutrients, pH balancing agents, and/or thickeners, among others. In the figure, and for illustrative purposes only, the urea-formaldehyde condensate 102 has a filled circular cross-section. The shapes, sizes and relative amounts of the components in the figures help to simply distinguish the different components in the spherical urea-formaldehyde condensate fertilizers 100 and 200 and are not limiting. Other sizes and relative amounts of components are contemplated and may be readily manufactured. In the illustrative spherical urea-formaldehyde condensate fertilizer 100 embodiment, in certain aspects of the invention, the binder and/or flow promoter may act as a continuous phase to help bind the urea-formaldehyde condensate 102 and the binder and/or flow promoter 101 together to form the spherical urea-formaldehyde condensate fertilizer 100. In certain aspects, the spherical urea formaldehyde condensate fertilizer 200 does not include a binder and/or flow promoter 101 therein. It will be apparent to those of ordinary skill in the art that other configurations of the spherical urea-formaldehyde condensate fertilizers 100 and 200 are possible. Although fig. 1 illustrates a fertilizer that is completely spherical, it is contemplated that spherical fertilizers may include substantially spherical fertilizers in the context of the present invention. The substantially spherical shape may include an elliptical shape. The substantially spherical shape may include a ratio of lengths across a vertical axis of the particle cross-section, including a ratio of 0.5 to 2.0, preferably 0.8 to 1.2, more preferably 0.9 to 1.1 or a ratio of about 1.0.

The spherical urea formaldehyde condensate fertilizers 100 and 200 can be of various sizes. In some embodiments, the spherical urea formaldehyde condensate fertilizer has an average diameter of about 1mm to 8mm, 1mm to 4mm, or 2mm to 3.5mm, or any size therebetween.

B. Urea-formaldehyde condensate

The urea-formaldehyde condensate contains C₁To C₄A urea oligomer. In some cases, the urea-formaldehyde condensate comprises C₂To C₄A urea oligomer. In some cases, the urea-formaldehyde condensate comprises C₂And C₄A mixture of aldehydes. C₁To C₄Or C₂To C₄The/urea oligomer can be any C₁To C₄Or C₂To C₄A urea oligomer. C of spherical Urea-Formaldehyde condensate₁To C₄And C₂To C₄The aldehyde may be any C₁To C₄Or C₂To C₄Aldehydes, their preparationDerivatives or combinations thereof. In some cases, C₁To C₄Or C₂To C₄The aldehyde may be formaldehyde, butyraldehyde, isobutyraldehyde, crotonaldehyde, or any combination thereof. In some cases, the condensate contains less than 25, 20, 15, 10, 5, 4, 3, 2, or 1 weight percent urea.

C. Binders and flow promoters

The binder may be used to bind the components of the mixture together by adhesive and/or cohesive forces. The binder used in the spherical urea formaldehyde condensate fertilizer may be selected according to suitability in the granulation and/or spheronization or extrusion process for manufacturing the spherical urea formaldehyde condensate fertilizer. The binder may be a polymeric or non-polymeric binder. The melting point or softening temperature of the binder may be below the temperature at which the urea-formaldehyde condensate contained in the spherical urea-formaldehyde condensate fertilizer degrades or melts. In non-limiting examples, the temperature is less than 50 ℃, less than 40 ℃, less than 30 ℃, less than 20 ℃, or any temperature therebetween. In some cases, the adhesive is biodegradable. In some cases, the binder is water soluble.

Non-limiting examples of binders include bleached wheat flour, guar gum, calcium lignosulfonate, gelatin, seaweed extract, plaster of paris, flour, starch, cellulose, gluten, colloidal silica, kaolin, bentonite, polyethylene glycol (PEG), polycaprolactone, low molecular weight polyvinyl acetate, 60 wt.% urea solution, polyacrylamide, polyacrylic acid, polyacrylonitrile, Hydroxypropylmethylcellulose (HPMC), biodegradable polylactic acid, and other biodegradable polymeric materials such as polylactic acid, poly (3-hydroxypropionic acid), polyvinyl alcohol, polycaprolactone, poly-L-lactide, polybutylene succinate, and biodegradable starch-based polymers.

The flow promoters may be used to increase the fluidity of the urea-formaldehyde condensate or to increase the ability of the urea-formaldehyde condensate to be pelletized and/or spheroidized. The flow promoter used in the spherical urea formaldehyde condensate fertilizer may be selected according to suitability in the granulation and/or spheroidization or extrusion process for manufacturing the spherical urea formaldehyde condensate fertilizer. The flow promoter may be polymeric or non-polymeric.

Non-limiting examples of flow promoters include bleached wheat flour, microcrystalline silicon dioxide, chitosan, natural gums such as agar, guar gum, clays such as bentonite, cellulose derivatives such as carboxymethyl cellulose, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose and hydroxypropyl methyl cellulose (HPMC).

The spherical urea formaldehyde condensate fertilizer may contain any amount of binder and/or flow promoter. The spherical urea formaldehyde condensate fertilizer may have a sufficient amount of binder to bind together the spherical fertilizer or the extrudate used to produce the spherical fertilizer. The spherical urea-formaldehyde condensate fertilizer may have a sufficient amount of flow promoter to enhance the flow of the urea-formaldehyde condensate through the extruder. The concentration of the binder and/or flow promoter may be 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1, or any concentration or range therebetween, based on the total weight of the spherical urea formaldehyde condensate fertilizer. In a preferred embodiment, the spherical urea formaldehyde condensate fertilizer contains from 0.2 wt% to 5 wt%, more preferably from 0.5 wt% to 1 wt%, or any value or range therebetween, of the binder and/or flow promoter. In some cases, no binder and/or flow promoter is used in the spherical urea formaldehyde condensate fertilizer.

The spherical urea-formaldehyde condensate fertilizer of the present invention may have desirable physical properties such as a desired level of abrasion resistance, strength, pelletizability, hygroscopicity, shape, and/or size distribution. Thus, the binder and/or flow promoter may be selected to optimize these properties.

D. Additional fertilizers

Additional fertilizer materials other than urea-formaldehyde condensate may be included in the spherical urea-formaldehyde condensate fertilizer or in the fertilizer composition or mixture used in the present invention. Additional fertilizers may be selected based on the particular needs of certain types of soil, climate or other growing conditions to maximize the effectiveness of the spherical urea-formaldehyde condensate fertilizer in enhancing plant growth and crop yield. Additional fertilizers may also be included in the spherical urea formaldehyde condensate fertilizer or in the fertilizer composition or mixture used in the present invention, including but not limited to micronutrients, primary nutrients, and secondary nutrients. The micronutrient may be an inorganic or organometallic compound such as boron, copper, iron, chloride, manganese, molybdenum, nickel or zinc in a form acceptable to plants. The primary nutrient may be a substance that delivers nitrogen, phosphorus and/or potassium to the plant. The nitrogen-containing primary nutrient may include urea, ammonium nitrate, ammonium sulfate, diammonium phosphate, monoammonium phosphate, urea formaldehyde, or a combination thereof. The secondary nutrient may be a substance that delivers calcium, magnesium and/or sulfur to the plant. The secondary nutrient may include lime, gypsum, calcium superphosphate, or a combination thereof.

pH buffers

The spherical urea formaldehyde condensate fertilizer of the present invention may also contain one or more than one pH buffering agent. Examples of suitable pH buffers include, but are not limited to, CaCO₃、MgO、KH₂PO₄、NaHCO₃Chalk, aluminum, magnesium hydroxide, aluminum hydroxide, sodium bicarbonate, and the like, and combinations thereof.

F. Blended fertilizer

The spherical urea-formaldehyde condensate fertilizer of the present invention may also be included in blend compositions comprising other fertilizers, such as other fertilizer granules. Additional fertilizers can be selected based on the particular needs of certain types of soil, climate, or other growing conditions to maximize the efficiency of the blend composition in enhancing plant growth and crop yield. Fig. 3 illustrates an embodiment of a method 300 of producing a blended fertilizer. For example, the spherical urea-formaldehyde condensate fertilizers 100, 200 of the present invention may be mixed with a non-spherical non-urea-formaldehyde condensate fertilizer 301. Mixing 302 may be performed by any type of mixing or blending equipment commonly available in the art (e.g., WJ-700, WJ-900, or WJ-1000 blenders from Whirlston Machinery (Zheng, China.) Once mixed, the fertilizer mixture may be stored 303 for future use or sale.

The spherical urea formaldehyde condensate fertilizer can be mixed with other fertilizers in any concentration. In some cases, the desired concentration is sufficient to meet the desired nutrient or micronutrient content in the mixture.

G. Method for producing spherical urea formaldehyde condensate fertilizer and blended fertilizer

In some embodiments, a spherical urea-formaldehyde condensate fertilizer is made by combining a urea-formaldehyde condensate with water and optionally one or more of a flow promoter, a binder, a micronutrient, and/or combinations thereof. In some cases, other suitable substances, such as pH balancing agents, are combined with other additives. The mixture may optionally be extruded. Extrudates may be formed by mixing the ingredients in dry form, adding any solvent if desired, and further mixing to produce an extrudable composition. A solvent, such as water, may be required to make the extrudable composition. The extrusion may be accomplished using suitable extruder equipment known in the art, and may be carried out at a temperature of 0 ℃ to 50 ℃, a screw speed of 20rpm to 300rpm, a pressure of 1 bar to 50 bar, and/or wherein the extruder comprises a multi-feeder and comprises extrusion components including main drives, shafts, screws, barrels, and/or dies. In some embodiments, the extrusion process comprises slicing the extrudate. The extrudate may be sliced by using a die or by other methods known in the art. The mold may be a perforated mold.

In some embodiments, the spherical urea-formaldehyde condensate fertilizer is prepared by forming the spherical urea-formaldehyde condensate fertilizer from a non-extruded combination of ingredients or an extrudate. The spherical urea formaldehyde condensate fertilizer may have a diameter of about 1mm to 4 mm. The spherical urea formaldehyde condensate fertilizer may have a substantially spherical shape. In some cases, the spheres may be formed by granulation and/or use of a spheronizer. Granulation and/or spheronization may be carried out after the chemical reaction to produce the urea-formaldehyde condensate is complete and/or after the formation of a dried fertilizer. The granulator may be any suitable granulator, for example a pan granulator or a drum granulator. The pelletizer can be any suitable pelletizer. The pelletizer may be a disk pelletizer. In some cases, the disks may have a cross-grid pattern. The pelletizer can be operated at an air pressure of 0.5 bar to 10 bar and/or a speed of 1rpm to 5000 rpm.

The spherical urea formaldehyde condensate fertilizer can be prepared by using a granulator or using a spheroidizer after granulation. Granulation may be carried out in any suitable granulator. Non-limiting examples of granulators include pan granulators or drum granulators. To make a spherical urea formaldehyde condensate fertilizer, spherical urea formaldehyde condensate fertilizer ingredients, which may include urea formaldehyde condensate, and one or more than one or none of water, binder, flow promoter, or other suitable ingredients, are mixed and pelletized. In some cases, granulation is performed using a powdered urea-formaldehyde condensate and water. The granulator may be configured to tumble and heat the ingredients under heat in a rotary granulator, causing the ingredients to aggregate and form granules. In some cases, the pelletizer is operated at 500RPM to 10RPM and is operated with a gas stream at a pressure of 0.1 bar to 10 bar and a temperature of 40 ℃ to 100 ℃. The granulation process may be performed for any time, for example, 1 minute to 15 minutes.

The granulated particles may be further processed to spheronize and/or dry them, if desired. In some cases, the particles are further spheronized in a spheronizer having an air flow and spheronizer disks to produce spheres. The disk may be a patterned pelletizer disk with a grid pattern.

Fig. 2 and 4 each illustrate an embodiment of methods 201 and 400, respectively, by which the spherical urea-formaldehyde condensate fertilizers of the present invention can be made. As shown in fig. 2, to make a spherical urea-formaldehyde condensate fertilizer 200, spherical urea-formaldehyde condensate fertilizer components 202, which may include urea-formaldehyde condensate, are mixed, with one or more or none of water, binder, flow promoter, or other suitable components. In some cases, the mixture may be extruded 203. The extruder may be configured to propel the mixed fertilizer ingredients through the die 204 during extrusion, and cutting tools associated with the die chop the extrudate into pellets, which may be further processed (not shown) for drying, if desired. The mixed or extruded or pelletized or unmixed urea formaldehyde condensate forms spheres upon spheroidization 205. In some cases, the spheres are formed by using a spheronizer. As shown in fig. 4, in some cases, the starting materials for the urea-formaldehyde condensate fertilizer can be fed to an extruder, such as a counter-rotating twin screw extruder 401 (e.g., temperature and pressure sensors 402) that controls temperature and pressure. The ingredients may be mixed and extruded through an extruder. In some cases, the extrudate is cut through a perforated die 403 to form pellets 404. The particles 404 may be non-spherical. In some cases, the particles are then further spheroidized in a spheroidizer having a gas stream 405 and spheroidizer disks to produce particles 407. The disk may be a patterned pelletizer disk 406 with a grid pattern. The control panel 408 may be used to operate the pelletizer. The process 400 may include a feed 409 to make pellets 407 and a motor 410, gearbox 411, and control system 412 to operate the extruder 401. Cooling water for the jacket and process air inlet 413 may be used with the pelletizer disk 406 having a grid pattern to produce the particles 407.

After final processing by any of the above methods, at least a majority of the spherical urea-formaldehyde condensate fertilizer can be within the desired size. However, some spherical condensate fertilizers may be too large or too small. These off-spec spherical urea formaldehyde condensate fertilizers can be separated, crushed and the powder material can be re-directed through the process. In some embodiments, the recovered composition is mixed with a spherical urea formaldehyde condensate fertilizer. These compositions may comprise from 0 wt% to 50 wt% of the recovered composition. However, an advantage of the method claimed herein is that the amount of off-spec spherical urea-formaldehyde condensate fertilizer can be reduced, and can be completely eliminated, due in part to the materials used and/or the processing conditions used.

In some cases, blended fertilizers are manufactured. Fig. 3 illustrates an embodiment of a method 300 of producing a blended fertilizer. To make a blended fertilizer, the spherical urea-formaldehyde condensate fertilizer of the present invention (e.g., 100 and/or 200) may be mixed with other fertilizers 300, micronutrients, plant protection agents, fillers, and/or other fertilizer ingredients. Mixing may be performed by known methods such as mixing 302, pouring mixing, vortexing, shaking, and the like. In one case, a fertilizer mixing unit may be used. Fertilizer mixing units are commercially available. In some cases, a ribbon blender may be used.

H. Method of using spherical urea formaldehyde condensate fertilizer

The spherical urea formaldehyde condensate fertilizer of the present invention may be used in methods of increasing the amount of nitrogen in soil and enhancing plant growth. These methods may comprise applying an effective amount of a composition comprising the spherical urea formaldehyde condensate fertilizer of the present invention to soil. The method may comprise increasing plant growth and yield. The method can include applying the spherical urea-formaldehyde condensate fertilizer of the present invention to at least one of soil, an organism, a liquid carrier, a liquid solvent, and the like.

Non-limiting examples of plants that may benefit from the fertilizer of the present invention include vines, trees, shrubs, stalks, ferns, and the like. Plants may include fruit crops, vines, ornamentals, food crops, lumber and harvested plants. The plant may include any gymnosperm, angiosperm and/or fern.

The effect of a composition comprising the spherical urea formaldehyde condensate fertilizer of the present invention can be determined by measuring the amount of nitrogen in the soil at different times after application of the fertilizer composition to one or more than one soil. The effect of the fertilizer composition can also be compared directly to other fertilizer compositions by side-by-side comparison in the same soil under the same conditions.

Examples

The present invention will be described in more detail by way of specific examples. The following examples are provided for illustrative purposes only and are not intended to limit the invention in any way. Those skilled in the art will readily recognize a variety of noncritical parameters that may be varied or altered to produce substantially the same results.

Example 1

Method for producing spherical urea formaldehyde condensate fertilizer

Pelletization of methylene urea-isobutylidene diurea (MU-IBDU) fertilizers was achieved by spheronizing or first extruding a wet MU-IBDU mixture and then spheronizing or pelletizing the wet MU-IBDU mixture.

Spheronizer-briefly, granulation of MU-IBDU powder was performed in a disk Spheronizer (Multi Bowl Spheronizer, 250mm, manufactured by Caleva). The dried MU-IBDU powder was wetted with 20% to 25% water and added to a spheronizer. The spheronizer was operated using a cross grid plate with a 3mm pattern at 0.5 bar air pressure and 2500rpm for 3 to 10 minutes to obtain the desired particles. The MU-IBDU particles are agglomerated and form spherical particles. Without being bound by theory, it is believed that the continuous collision of the moist material with the walls of the pelletizer and friction plate in the presence of the gas stream causes the particles to become spherical. The crush strength of the granules MU-IBDU produced by both methods is shown in Table 2.

Extrusion-spheronizer-briefly, granulation of MU-IBDU was performed using an extruder and a spheronizer. See fig. 4. The dried MU-IBDU powder was wetted with 20% to 25% water and fed into an extruder. The resulting wetted particles are then spheronized using a spheronizer. The spheronizer was operated using a 3mm cross grid plate at 0.5 bar air pressure and 2500rpm for 5 to 10 minutes to obtain the desired particles. During extrusion, different flow promoters were also tested, such as bleached wheat flour, guar gum, Hydroxypropylmethylcellulose (HPMC), calcium lignosulfonate, and gelatin. HPMC and guar gum perform best among them. The non-limiting ratio of flow promoters is from 0.1 wt% to 10 wt% and may be adjusted depending on the ratio of MU and IBDU present in the MU-IBDU product. In one embodiment, a mixture of MU-IBDU powder, 1 wt.% HPMC, and 20 to 25 wt.% water is added to an extruder having a die with a bore of 1.5mm to 2.5 mm. The extruder was operated at a speed of 100rpm and a pressure of 1 to 3 bar at the die lip.

MU-IBDU products may also be further enriched with other primary fertilizer elements, secondary fertilizer elements and trace elements using this technique.

The particles obtained by this method exhibit good physical properties. The yield obtained by this method is about 95% with only 4% to 5% loss of material. Spherical MU-IBDU granules with improved physical properties can be used for blending with other fertilizers, reducing the risk of the granules being crushed. The crush strength of the un-spheronized and dried MU-IBDU extrudate is shown in table 1:

TABLE 1

The spheroidizing device operates as follows: disc speed-2500 RPM; disc groove geometry-a cross grid plate with a 3mm pattern; retention time-5 minutes; air pressure-0.5 bar. The wet MU-IBDU extrudate was immediately fed into a spheronizer and processed under the conditions described above. The particles obtained from the spheronizer were dried at 80 ℃ for 3 to 4 hours.

MU-IBDU particles with a size of 1.5mm to 2.5mm were obtained with a yield of 95%. The crush strength of the granules MU-IBDU produced by both methods is shown in Table 2. A combined extrusion and spheronization process was found to improve the crush strength of the particulate MU-IBDU.

TABLE 2

Granulator-briefly, granulation of MU-IBDU powder was carried out using a wet process in a pan granulator/drum granulator. The dried MU-IBDU powder was wetted with 10% to 25% water and charged to a pan/drum granulator. During the continuous rotation of the pan granulator/drum, the granules are agglomerated and formed into granules. Granulation was carried out in a laboratory grade pan/drum granulator with a maximum productivity of 3 kg. The disc/drum contained two baffles, 4 inches and 6 inches wide across the length of the disc/drum. The baffles were placed at a 45 ° angle to the center of the disc/drum.

For granulation of MU-IBDU (75/25), a mixture of MU-IBDU (75:25) powder (1kg) and 0.5 wt% HPMC was thoroughly mixed. Then, 15 to 25% by weight of water is added and mixed until the binder is uniformly dispersed. The resulting MU-IBDU wet mass was manually fed to a pan/drum and operated under the following process conditions.

The technological parameters are as follows:

disc/drum speed: 20RPM

The baffle type: flat plate

Retention time: 10 minutes

Air pressure: 0.5 bar

Temperature of hot air: 75 deg.C

The particles obtained from the spheronizer were dried at 80 ℃ for 16 hours. Homogeneous granules with a size of 1.5mm to 2.5mm were obtained with a yield of 60%.

Example 2 (prophetic example)

Sample analysis

The properties of the fertilizers disclosed herein can be tested. The crush strength of some samples can be measured using a crush strength analyzer to determine the strength of the fertilizer.