WO2019204313A1

WO2019204313A1 - Iron chelate suspension concentrate compositions

Info

Publication number: WO2019204313A1
Application number: PCT/US2019/027689
Authority: WO
Inventors: Baozhong Xing; Randall Worthley
Original assignee: Loveland Products Inc
Current assignee: Loveland Products Inc
Priority date: 2018-04-16
Filing date: 2019-04-16
Publication date: 2019-10-24
Anticipated expiration: 2020-10-16

Abstract

In some embodiments, a suspension concentrate product includes about 40% to about 60% iron complex by weight of the suspension concentrate product, at least one gum, at least one polymer, water, optionally one or more additives and optionally one or more solvents. The iron complex is selected from Fe-EDDHSA, Fe-EDDHA or a combination thereof.

Description

IRON CHELATE SUSPENSION CONCENTRATE COMPOSITIONS

CROSS-REFERENCE TO RELATED APPLICATION

[0001 ] This application claims priority to Provisional Application No.

62/658,382, filed April 16, 2018, which is herein incorporated by reference in its entirety.

FIELD

[0002] The present disclosure relates generally to suspension concentrate compositions comprising an iron chelate and methods of making. More particularly, the present disclosure relates to suspension concentrate compositions comprising iron chelated with 2-[2-[[carboxy-(2-hydroxy-5-sulfophenyl)methyl]amino]ethylamino]- 2-(2-hydroxy-5-sulfophenyl)acetic acid (EDDHSA) and/or ethylenediamine-N, N’-bis (2-ydroxyphenylacetic acid) (EDDHA). The present disclosure also relates to a use solution formed by diluting the suspension concentrate with water.

BACKGROUND

[0003] Nutrient uptake is an important part of plant growth. Plants deficient in certain types of nutrients can exhibit stunted growth, low yield, and/or poor fruit quality. One particularly important nutrient is iron, which supports chlorophyll production, respiration, and tissue development in the plant. Plants deficient in iron can develop leaf chlorosis (also known as“leaf yellowing”), stunted growth, and/or tissue necrosis.

[0004] Some types of soils are naturally lower in certain nutrients that are important for plant development. For example, calcareous soil is characterized as a type of soil having low iron content or, in some instances, having iron in a form not readily absorbable by most plants. Therefore, seeds planted in soils such as these may require additional nutrient supplementation, such as use of fertilizers with supplementary iron to increase iron availability and/or uptake. An example of supplementary iron used in such fertilizers is iron chelate, which can be added to fertilizers to increase plant iron uptake.

[0005] Historically, one challenge with iron chelates in concentrate solutions their tendency to react and form precipitate upon mixing with water. These precipitates can cause sticky, lumpy, and/or non-dissolvable particulate, often resulting in a low-stability use mixture that is difficult to use. One solution to this is to reduce the concentration of iron in the use mixture. However, a low weight percentage of iron and/or iron chelates often results in poor effectiveness of the use solution and reduced uptake of iron in the plants. Therefore, there is a desire in the industry for suspension concentrate and/or use solution for treating iron deficiency that includes an effective amount of iron and is also stable in a variety of conditions.

SUMMARY

[0006] In some embodiments, a suspension concentrate product includes about 40% to 60% iron complex by weight of the suspension concentrate product, at least one gum, at least one polymer, water, optionally one or more additives and optionally one or more solvents. The iron complex is selected from Fe-EDDHSA, Fe-EDDHA or a combination thereof. The at least one gum, at least one polymer, water, additives and solvents combined form the remainder by weight of the suspension concentrate product. The suspension concentrate product has a pH of 6 to 8.

[0007] In some embodiments, a use solution includes about 40% to 60% iron complex by weight of the product, the iron complex consisting of Fe-EDDHSA, Fe- EDDHA or a combination thereof, at least one gum, at least one polymer, water and a fertilizer.

DETAILED DESCRIPTION

[0008] The present disclosure generally relates to a suspension concentrate containing an iron complex including Fe-EDDHSA and/or Fe-EDDHA, a thickener system including a gum and a polymer and water. The suspension concentrate can include about 40% to about 60% by weight iron complex and the remainder is a combination of a thickener system and water. In some embodiments, the

suspension concentrate can include about 50% by weight iron complex and 50% by weight thickener system and water, in combination. A suspension concentrate contains a suspension of particles suspended in a fluid, such as water. The suspension is stable for a period of time such that the particles do not settle out. The suspension concentrate is combined with water and optional other components to form a use solution for application to seeds and/or plants.

[0009] The iron complex generally includes iron chelated with one or more chelating agents. Chelating agents are small molecules that bind readily to metal ions. Suitable chelating agents include EDDHSA and ethylenediamine-N, N’-bis (2- ydroxyphenylacetic acid) (EDDHA). When the chelating agent is bound to iron, the compounds can be referred to as iron chelates (e.g., Fe-EDDHSA and Fe-EDDHA, respectively). Iron chelates can be used to maintain iron availability in soil as well as improve iron uptake in plants and seeds.

[00010] The iron complex contains Fe-EDDFISA and/or Fe-EDDHA. In some embodiments, the iron complex may contain a greater amount of Fe-EDDHSA by weight than Fe-EDDHA. In some examples, the iron complex includes from about 90% to 100% Fe-EDDHSA by weight of the iron complex and from about 0% to 10% Fe-EDDHA by weight of the iron complex. For example, the iron complex can include from about 91 % to about 99%, 92% to about 98%, 93% to about 97%, 94% to about 96%, or about 95% Fe-EDDHSA, and the iron complex can include from about 1 % to 9%, 2% to 8%, 3% to 7%, 4% to 6%, or about 5% Fe-EDDHA.

[00011 ] In some embodiments, the iron complex may contain only Fe-EDDHA.

[00012] The suspension concentrate has a high concentration of iron. For example, the suspension concentrate can contain 3% or more of iron by weight. In some embodiments, the suspension concentrate contains 3% to 4% iron by weight. The suspension concentrate can include from 10% to 60% by weight of the iron complex. In some embodiments, the suspension concentrate can include 35% to 60% by weight Fe-EDDHSA and 5% to 30% by weight Fe-EDDHA. It has been found that a suspension concentrate having greater than 30% by weight Fe-EDDHA by weight of the suspension concentrate may not have suitable stability.

[00013] The suspension concentrate includes a thickener system containing at least one gum and at least polymer. Gums are polysaccharides. Suitable gums include xanthan gum and guar gum. In some embodiments, it has been found that xanthan gum may create a jelly-like or gel-like suspension product when mixed with the other ingredients. Guar gum has been found to be another suitable stabilizing gum. While guar gum is a weak suspension agent alone, it has been found that it forms a suitable suspension concentrate when combined with a polymer, such as

PAM, and/or a glycol solvent, such as ethylene glycol (EG). [00014] It has been found that gums can stabilize the suspension concentrate at room temperature and at high temperatures. In some embodiments, suspension concentrates containing gum may form crystals at low temperature (i.e. , 2°C).

However, the crystallization does not affect stability of the suspension concentrate or mixing or diluting with water. In some embodiments, the suspension concentrate can include 0.01 % to 0.45% by weight of one or more gums.

[00015] The thickener system of the suspension concentrate also includes one or more polymers, which can further aid in stabilization of the solution. Examples of suitable polymers can include polyacrylamide (PAM), polyvinylpyrrolidone (PVP), and polyvinyl alcohol (PVA). In some embodiments, the suspension concentrate can include 0.01 % to 0.2% by weight of a polymer.

[00016] In some examples, the suspension concentrate can include from about 0.01 % to about 0.2% polymers by weight of the suspension concentrate. In some examples, the amount of polymer in the suspension concentrate may be about equal to the amount of gum in the suspension concentrate. In some examples, the amount of polymer may be less than the amount of gum in the suspension concentrate.

[00017] In some examples, the suspension concentrate may include only one polymer. For example, the suspension concentrate may contain PAM, PVP, or PVA. In some examples, the suspension concentrate may contain more than one polymer. For example, the suspension concentrate may include one or more of PAM, PVP, and PVA, or other polymers as desirable.

[00018] As discussed above, in some embodiments, the gums, such as xanthan gum, can form a jelly-like or gel-like suspension. It has been found that in some embodiments, the polymer, such as PAM, can reduce the jelly-like or gelling properties of the suspension concentrate, creating a more commercially suitable product.

[00019] The suspension concentrate also includes water. In some

embodiments, the suspension concentrate may include one or more optional additives and/or inevitable impurities. Examples of optional additives can include crystallization modifiers, corrosion inhibitors, salts, surfactants, antifoam agents and other chemicals.

[00020] In some embodiments, the suspension concentrate additionally includes a solvent such as a glycol. Suitable glycol solvents include ethylene glycol and propylene glycol. In some embodiments, the glycol solvent, such as ethylene glycol, can assist with preventing or reducing gelling of the gum(s). In some embodiments, the glycol solvent, such as ethylene glycol, can additionally or alternatively assist with reducing crystallization for example at lower temperatures. For example, in some embodiments, no crystallization occurs in the suspension concentrate at 2°C when glycerin is present wherein some crystallization occurs in the same suspension concentrate that does not include glycerin.

[00021 ] Suspension concentrates enable storing smaller volumes of material as compared to storage of a diluted use solution. In some instances, suspension concentrate may be stored for long periods of time and at a variety of temperatures. For example, the suspension concentrate may be stored throughout the harvest season or during winter months. In some embodiments, the suspension concentrate is stable at near freezing temperatures and at temperatures well above ambient temperature (i.e. , at temperatures greater than 20°C, greater than 30°C, greater than 40°C, or as high as 50°C). In some embodiments, the suspension concentrate is stable between 2°C and 50°C. In some embodiments, particles within the

suspension concentrate are uniformly distributed at temperatures between about 10°C and 50°C. At temperatures below 10°C, the product may experience slight settling, which can be mixed back into the product by stirring or shaking.

[00022] The iron in a composition can react with other components of the solution, which can cause the solution to decompose, gel, solidify, or form precipitate or deposits that are difficult to redissolve. A stable solution refers to a solution that does not readily decompose over time and/or does not readily form precipitates or substantially thicken at low temperatures. In some instances, a stable solution may partially crystallize, but any crystals that do form readily redissolve into solution. For example, the crystals can redissolve when the suspension concentrate is mixed with water, or when the temperature of the solution is increased. For example, in some embodiments,

[00023] In some examples, the suspension concentrate includes about 50% by weight iron complex, and the balance is comprised of the thickener system (i.e., gum, polymer or a combination thereof) and water. In some embodiments, the suspension concentrate includes about 50% by weight iron complex, about 0.01 - 0.45% by weight gum, about 0.01 -0.3% by weight polymer, and a balance of water and/or other optional additives or inevitable impurities. [00024] The suspension concentrate has a neutral or approximately neutral pH. For example, the suspension concentrate can have a pH of from about 6 to 8, from about 6.5 to about 8, or from about 6.5 to about 7.5.

[00025] The suspension concentrate may have a volatile concentration at 75°C to 95°C of 30% to 55% by weight.

[00026] The suspension concentrate can be formed by mixing the above- mentioned components together to form a stable suspended concentrate product. In some examples, the iron complex is mixed with a suitable amount of gum, polymer, and water and/or other desired additives and continuously mixed until a uniform, suspended concentrate forms. Preparation of the suspension concentrate is described in further detail in the example section.

Use Solution

[00027] A use solution, as discussed herein, refers to a solution or suspension concentrate that has been diluted with water and/or other components to form a solution having a suitable concentration of ingredients to be applied to plants or seeds. In some examples, the use solution includes the suspension concentrate, a fertilizer, and water. Suitable fertilizers include starter fertilizers, which refers to a fertilizer that is applied to meet nutrient demands of a seed before the plant’s root system develops. One example of a suitable starter fertilizer is Levitate™ starter fertilizer available from Loveland Products, Inc.

[00028] In some examples, the use solution includes from about 1 % to about

20% suspension concentrate by weight of the use solution, from about 1 % to about

16% suspension concentrate by weight of the use solution, or from about 2% to about 16% suspension concentrate by weight of the use solution.

[00029] In some examples, the use solution includes from about 1 % to about

10% phosphate by weight of the use solution. Phosphate has low compatibility with iron and use solutions containing both components may having a stability of less than 30 minutes. That is, in previous use solutions, the compatibility of phosphate and iron resulted in decomposition, gelling, solidification or formation precipitates or deposits within 30 minutes of preparing the use solution. In some embodiments of the current disclosure, a use solution containing phosphate and iron is stable for at least two hours. This enables the use solution to be applied as a uniform solution

(i.e. , without differences in constituent concentrations due to settling or separation.) [00030] In some examples, the use solution includes a balance of water and/or other optional additives and inevitable impurities. The concentration of ingredients in the use solution can vary depending on the desired end use. In some examples, a ratio of the suspended concentrate product-to-fertilizer-to-water may be about 7 to 13 to 20. However, other ratios are contemplated depending on the desired concentration of the use solution. The pH of the use solution can also vary depending on the desired end use or the average pH of the soil. In some examples, the pH of the use solution is from about 6 to 8, from about 6.5 to about 8, or from about 6.5 to about 7.5.

[00031 ] The use solution can be formed by mixing the components in a tank (i.e. , tank mix) followed by application to the field or crop. In some examples, the use solution or tank mix is stable for at least 1 hours, at least 2 hours or at least 3 hours. In some embodiments, the use solution is stable for up to about 3 hours, up to 4 hours or up to 5 hours.

[00032] The use solution may be used in-furrow applications and foliar applications. For example, the use solution may be applied in-furrow for soybeans.

[00033] The present invention is more particularly described in the following examples that are intended as illustrations only, since numerous modifications and variations within the scope of the present invention will be apparent to those of skill in the art. Unless otherwise noted, all parts, percentages, and ratios in the following examples are on a weight basis.

EXAMPLES

Samples 1-10

[00034] Suspension concentrate solutions were formed by combining Fe- EDDHSA, Fe-EDDHA, a 1wt% PAM solution (aqueous solution), 1.5 wt% xanthan solution (aqueous solution), and water in the weight amount (grams) shown in Table 1. The samples were stored at 2°C, room temperature and 50°C for a storage period of one month. After the storage period, the samples were evaluated for uniformity (such as the absence of settling or separation) and the thickness of the sample was characterized as follows, in which the thickness increases with an increased rating:

Table 1.

[00035] Observations after the storage period are provided in Table 2.

Table 2.

Samples 11-34

[00036] Suspension concentrate solutions were formed by combining Fe- EDDHSA, Fe-EDDHA, a 1wt% PAM solution (aqueous solution), 1 wt% guar gum solution (aqueous solution), 1.5 wt% xanthan solution (aqueous solution), and water in the weight amount (grams) shown in Table 3. The samples were stored at 2°C, room temperature and 50°C for a storage period of four months. After the storage period, the samples were evaluated for uniformity (such as the absence of settling or separation) and the thickness of the sample was characterized as follows, in which the viscosity or thickness increases with an increased rating:

Table 3.

[00037] Observations after the storage period are provided in Table 4.

Table 4.

[00038] Sample 31 suggests that an acceptable suspension concentrate can be formed when a large amount of guar gum is combined with PAM. Samples 35-46

[00039] Suspension concentrate solutions were formed by combining Fe- EDDHSA, Fe-EDDHA, a 1wt% PAM solution (aqueous solution), 1 wt% guar gum solution (aqueous solution), 1.5 wt% xanthan solution (aqueous solution), water, and ethylene glycol (EG) in the weight amounts shown in Table 5. The samples were stored at 2°C and 50°C for a storage period of four months.

Table 5.

[00040] Observations after the storage period are provided in Table 6.

Table 6.

[00041 ] Samples 38-41 indicate that acceptable suspension concentrate solutions can be formed by combining guar gum with PAM and a glycol solvent, such as ethylene glycol.

Samples 35-43

[00042] Suspension concentrate solutions were formed by combining Fe- EDDHSA, Fe-EDDHA, a 1wt% PAM solution (aqueous solution), 1 wt% guar gum solution (aqueous solution), 1.5 wt% xanthan solution (aqueous solution), and water in the weight amounts shown in Table 7. The samples were stored at 2°C for a storage period of five months.

Table 7.

[00043] Observations after the storage period are provided in Table 8. The samples indicate that the viscosity (or jelly-likeness) of the sample increases with increasing amounts of xanthan gum, including in samples containing PAM, guar gum and xanthan gum. Table 8.

Samples 49-60

[00044] Suspension concentrate solutions were formed by combining Fe- EDDHSA, Fe-EDDHA, a 1wt% PAM solution (aqueous solution), 1 wt% guar gum solution (aqueous solution), 1.5 wt% xanthan solution (aqueous solution), and water in the weight amounts shown in Table 9. The samples were stored at 2°C, room temperature and 50°C for a storage period of six months.

Table 9.

[00045] Observations after the storage period are provided in Table 10.

Table 10.

Samples 61-113

[00046] Suspension concentrate solutions were formed by combining Fe- EDDHSA, Fe-EDDHA, a 1wt% PAM solution (aqueous solution), 1 wt% guar gum solution (aqueous solution), 1.5 wt% xanthan solution (aqueous solution), water, and glycol solvent (ethylene glycol (EG) or propylene glycol (PG) in the weight amounts shown in Table 11. The samples were stored at 2°C, room temperature and 50°C for a storage period of six months.

Table 11.

[00047] Observations after the storage period are provided in Table 12.

Table 12.

Claims

WHAT IS CLAIMED IS:

1. A suspension concentrate product, comprising:

about 40% to about 60% by weight iron complex by weight of the suspension concentrate product, the iron complex consisting of Fe-EDDHSA, Fe- EDDHA or a combination thereof;

at least one gum;

at least one polymer;

water;

optionally one or more additives; and

optionally one or more solvents, wherein the at least one gum, at least one polymer, water and optional additives and solvents are present in a combined amount of the remainder by weight of the suspension concentrate product, and wherein the suspension concentrate product has a pH of 6 to 8.

2. The suspension concentrate product of claim 1 , wherein the iron complex is present in an amount of about 50% by weight of the suspension concentrate.

3. The suspension concentrate product of claim 1 , wherein the iron complex comprises Fe-EDDHSA and Fe-EDDHA and wherein the Fe-EDDHSA is present in amount of at least 50% by weight of the iron complex.

4. The suspension concentrate product of claim 3, wherein the iron complex comprises Fe-EDDHSA and Fe-EDDHA and wherein the Fe-EDDHA is present in an amount of 1 % to 30% by weight of the suspension concentrate.

5. The suspension concentrate product of claim 1 , wherein the gum is xanthan gum.

6. The suspension concentrate product of claim 1 , wherein the polymer is selected from a group consisting of polyacrylamide (PAM), polyvinylpyrrolidone (PVP), and polyvinyl alcohol (PVA) and combinations thereof.

7. The suspension concentrate product of claim 6, wherein the polymer is polyvinyl alcohol (PVA).

8. The suspension concentrate product of claim 1 , wherein the gum is xanthan gum and the polymer includes polyacrylamide (PAM).

9. The suspension concentrate product of claim 1 , wherein the suspension concentrate product is stable from a temperature of about 2°C to 50°C when stored for a period of at least 24 hours.

10. The suspension concentrate product of claim 1 , wherein the suspension concentrate includes a glycol solvent.

11. The suspension concentrate product of claim 1 , wherein the gum is guar gum.

12. The suspension concentrate product of claim 1 , wherein the gum is guar gum and the polymer includes polyacrylamide (PAM).

13. The suspension concentrate product of claim 1 , wherein the gum includes guar gum and xanthan gum, the polymer includes polyacrylamide (PAM) and the solvent is a glycol solvent.

14. A use solution comprising:

about 40% to about 60% iron complex by weight of the product, the iron complex consisting of Fe-EDDHSA, Fe-EDDHA or a combination thereof; at least one gum;

at least one polymer;

water; and

a fertilizer.

15. The composition of claim 14, wherein the gum includes xanthan gum and the polymer includes polyacrylamide (PAM).

16. The composition of claim 14, wherein the use solution is stable from a temperature of about 2°C to 50°C for at least 5 hours.

17. The composition of claim 14, wherein the gum is guar gum and the polymer includes polyacrylamide (PAM).

18. The composition of claim 14, wherein the gum includes guar gum and xanthan gum, the polymer includes polyacrylamide (PAM) and the composition further includes a glycol solvent.