Compositions and methods for improving superabsorbent polymer fluidity

Abstract

A method comprising mixing a dry hydrophobic material with a dry superabsorbent polymer to improve the flowability of the polymer in a machine channel with a residence time under humid conditions. In agriculture, the application of superabsorbent polymers aids in the growth of plants under increasingly hot and dry conditions. However, the dry bulk planting applications commonly used in agriculture require the dry amendments to pass through restricted channels and narrow orifices. This is problematic because these polymers rapidly absorb water from the environment and adhere to the planting equipment, causing contamination and clogging. The improved flowability provided by the compositions disclosed herein is to such an extent that superabsorbent starch-like polymers can be applied using dry bulk planting applications in Florida under the humid conditions of spring. Surprisingly, the dry mixture improves flowability without destroying the ability of the polymer to rapidly absorb water from rain.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 144,137, filed February 1, 2021, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This invention relates to a mixture of a dry hydrophobic material and a dry superabsorbent polymer to improve the flowability of the superabsorbent polymer in dry bulk planting applications in agriculture. Background Technology

[0004] With rising temperatures and the emergence of drought and drought-like conditions, there is a need to improve soil water retention capacity to sustain crop growth. Superabsorbent polymers, such as ZEBA, a starch-based product sold by UPL NA Inc., have been used as soil conditioners and seed coatings to maintain a constant supply of water for germinating seeds, seedlings, and plants throughout the growing season. These polymers act like sponges, absorbing more than 400 times their original weight in water to form hydrogels that slowly release water to the plant when needed.

[0005] Unfortunately, a limitation of the superabsorbent properties of these polymers is their rapid absorption of water under humid conditions, which often leads to scaling and clogging of the limited channels and narrow openings of equipment used in dry, batch application processes in modern agriculture. These problems severely limit the practicality of these products in agriculture.

[0006] Therefore, there remains an unmet need for compositions and methods to improve the flowability of superabsorbent polymers used in dry, batch planting applications. This disclosure provides such compositions and methods. Summary of the Invention

[0007] In one aspect, a method is provided for improving the flowability of dried superabsorbent polymers used in dry bulk application in agriculture. The method involves mixing the dried superabsorbent polymer with a dried hydrophobic material, which unexpectedly improves the flowability of the dried superabsorbent polymer in moist environments without compromising the polymer's effectiveness in the soil. After being applied to the soil as a dry mixture, the superabsorbent polymer remains capable of rapidly absorbing moisture from rainwater.

[0008] On the one hand, dried compositions are provided for improving the flowability of dried superabsorbent polymers, particularly for improving the flowability of dried superabsorbent polymers used in batch application in agriculture. The dried compositions comprise mixtures of superabsorbent polymers and hydrophobic materials. Examples of superabsorbent polymers include, but are not limited to, starch-based polymers, starch-grafted poly(2-acrylamide-co-2-acrylic acid), xanthan gum, guar gum, hydroxyethyl carboxymethyl cellulose, carboxymethyl cellulose, polyacrylamide, and their derivatives and combinations. Examples of hydrophobic materials include, but are not limited to, i) combinations of protein powders and lipids, ii) micronized powders, iii) micronized waxes, iv) calcined silica, and v) treated clay particles and combinations thereof. Attached Figure Description

[0009] Figure 1 The experiment, conducted under very humid conditions in spring, illustrates the delivery of the dried composition of the present invention from a hopper through a restricted channel conveying pipe, wherein the dried composition is applied to the roots of pine seedlings at planting time.

[0010] Figure 2 It shows Figure 1 The dried composition in the hopper box during the experiment.

[0011] Figure 3 It shows in Figure 1 In the experiment, the dried composition was applied to newly dug furrows, and it was shown that the composition did not absorb a large amount of moisture.

[0012] Figure 4 It shows in Figure 1 The dried composition was applied to the furrows in the experiment.

[0013] Figure 5 An exemplary image of a combined mixture according to one or more embodiments disclosed herein is shown.

[0014] Figure 6 A flowchart describing one or more methods disclosed herein is shown. Detailed Implementation

[0015] To facilitate understanding of the principles of this disclosure, reference will now be made to preferred embodiments, which will be described using specific language. However, it should be understood that this is not intended to limit the scope of this disclosure, and such changes and further modifications to this disclosure as shown herein are considered to be commonly apparent to those skilled in the art to which this disclosure pertains.

[0016] According to long-standing patent law practice, the terms “a,” “an,” and “the” as used in this application (including the claims) mean “one or more.” Thus, for example, reference to “dried composition” includes a variety of dried compositions, unless the context clearly indicates otherwise, and so on.

[0017] In this specification and claims, the terms “comprise,” “comprises,” and “comprising” are used in a non-exclusive manner unless the context requires otherwise. Similarly, the terms “having” and “including,” and their grammatical variations, are intended to be non-restrictive, such that the listing of items does not exclude other similar items that may substitute for or be added to the listed items.

[0018] This disclosure provides drying compositions and methods for improving the flowability of superabsorbent polymers in dry, bulk planting applications in agriculture under both dry and very moist conditions. For example, dry amendments applied in agriculture are typically placed in seed furrows or applied to the soil in a similar manner. These types of soil application typically involve the use of metering boxes, hoppers, delivery pipes, nozzles, pneumatic distributors, air diffusers, air booms, air attachments, etc., requiring the application of the dry amendment through confined channels and narrow pores. Such dry bulk application is often problematic because superabsorbent polymers rapidly absorb moisture from the environment and adhere to planting equipment, leading to scaling and clogging. The compositions and methods of this disclosure can enhance the plantability and application of superabsorbent polymers or water-retaining dry materials in agriculture.

[0019] This paper discloses a surprising finding that mixing certain hydrophobic materials with superabsorbent polymers (such as the starch-based product ZEBA) significantly improves the flowability of dry batch application systems, even in high humidity environments. The unexpected effect of the mixture is that the superabsorbent polymer inhibits moisture retention. The effect of the mixture exceeded expectations. For example, it was initially thought that this combination would only make the superabsorbent polymer flow faster, but it would still stick to the equipment when exposed to moisture. The unexpected finding is that, after mixing with hydrophobic materials, the superabsorbent polymer can be metered and applied to the soil in wet planting conditions using dry batch processing equipment without compromising the polymer's effectiveness in the soil. After being applied to the soil as a dry mixture, the superabsorbent polymer is still able to rapidly absorb moisture after the first rainfall.

[0020] Other superabsorbent polymers can be used. Furthermore, other compounds or materials, such as zeolite hyaluronic acid, humic acid, chitin / chitosan polymers, volcanic soil and volcanic ash, kelp and seaweed powder, etc., can be used for similar purposes mentioned in this invention.

[0021] In the experiments of Example 1, a specific example of the drying compositions and methods disclosed herein for improving the flowability of superabsorbent polymers is described. This experiment was conducted to determine whether the hydrophobic material could be combined with the superabsorbent polymer starch-grafted-poly(2-acrylamide-co-2-acrylic acid), sold by United Phosphate Corporation under the name “ZEBA,” to allow its use in batch processing equipment for drying under wet spring planting conditions in Florida. Typically, this is not possible with superabsorbent polymers because superabsorbent polymer products tend to adhere to planting equipment under wet conditions, causing scaling and clogging and hindering application.

[0022] In the experiment, the dried hydrophobic material was "DUST," a product sold by Low Mu Tech. DUST was mixed at a ratio of 1 part DUST to 30 parts superabsorbent polymer. DUST is a formulation made from protein powder and lipids, used to improve seed flowability. Figure 1-4 A drying batch processing apparatus for use under very moist growing conditions is illustrated. A combination of hydrophobic materials and superabsorbent polymers produces a drying mixture that resists moisture absorption during growing and does not adhere to, clog, or contaminate the growing equipment. Regardless of any single mechanism of action, the mixture reduces electrostatic adhesion and product bridging of the superabsorbent polymer product, thereby improving the product's ability to flow through confined channels and narrow openings in dry to very moist environments.

[0023] The superabsorbent polymers disclosed herein include, but are not limited to, starch-based polymers, starch-grafted poly(2-acrylamide-co-2-acrylic acid), xanthan gum, guar gum, hydroxyethyl carboxymethyl cellulose, carboxymethyl cellulose, polyacrylamide, and their derivatives and combinations thereof.

[0024] Other superabsorbent polymers can be used. Furthermore, other compounds or materials, such as zeolite hyaluronic acid, humic acid, chitin / chitosan polymers, volcanic soil and volcanic ash, kelp and seaweed powder, etc., can be used for similar purposes mentioned in this invention.

[0025] The hydrophobic materials disclosed herein include flow aid compositions, such as, but not limited to, compositions comprising protein powders and lipids, micronized powders, micronized waxes, calcined silica, and treated clay particles.

[0026] The compositions comprising protein powder and lipids disclosed herein include: protein powder, including but not limited to soy protein powder, corn protein powder, oat protein powder, wheat protein powder, pea protein powder, rice protein powder, nut protein powder, seaweed protein powder, kelp protein powder, whey protein powder, casein protein powder, egg protein powder, albumin protein powder, blood meal protein powder, bone meal protein powder, fish protein powder, shellfish protein powder, plankton protein powder, yeast protein powder, bacterial protein powder, or combinations thereof; and lipids, including but not limited to lecithin, soy lecithin, vegetable oil, fish oil, animal fat, or combinations thereof.

[0027] The micronized powders and micronized waxes disclosed herein include, but are not limited to, rice bran wax, carnauba wax, alumina, poly(hydroxybutyrate-co-hydroxyvalerate) and combinations thereof.

[0028] In one aspect of this disclosure, a dried composition for improving the flowability of a superabsorbent polymer is provided, the composition comprising a mixture of the dried superabsorbent polymer of this disclosure and a dried hydrophobic material of this disclosure. The dried composition can be stored under dry conditions free of moisture.

[0029] On one hand, a dried composition for improving the flowability of a superabsorbent polymer is provided, the dried composition comprising a mixture of a dried superabsorbent polymer and a dried hydrophobic material, wherein the weight ratio of the superabsorbent polymer to the hydrophobic material is from 100:1 to 1:1000.

[0030] On the one hand, a dry composition is provided, comprising a mixture of a dried superabsorbent polymer and a dried hydrophobic material, wherein the weight ratio of the superabsorbent polymer to the hydrophobic material is 1:50 to 1:200.

[0031] On one hand, a method is provided for improving the flowability of a dried composition of a superabsorbent polymer in an agricultural environment. As an example, the environment could be a planting setting where the superabsorbent polymer is applied to furrows or other planting locations to provide concentrated moisture for seed germination. The method may include mixing the dried superabsorbent polymer of this disclosure with a dried hydrophobic material of this disclosure. The dried hydrophobic material may include i) protein powder and lipids, ii) micronized powder, iii) micronized wax, iv) calcined silica, v) treated clay particles, and combinations thereof.

[0032] Therefore, although the methods and systems have been described with reference to specific implementations, features and illustrative embodiments, it should be understood that the applicability of this subject matter is not limited thereto, but extends to and includes many other variations, modifications and alternative implementations, as would be conceived by one of ordinary skill in the art based on the disclosure herein.

[0033] Various combinations and sub-combinations of the structures and features described herein are contemplated and will be apparent to those skilled in the art upon which this disclosure is known. Unless otherwise indicated herein, any of the various features and elements disclosed herein may be combined with one or more other disclosed features and elements. Accordingly, the subject matter claimed below is intended to be broadly interpreted and understood to include all such variations, modifications, and alternative embodiments within its scope, and to include equivalents of the claims.

[0034] Example

[0035] Example 1

[0036] Use dry, batch application during periods of high humidity to improve the flowability of ZEBA.

[0037] Experiments were conducted to test whether the combination of the hydrophobic material (Low Mu Tech) and the product ZEBA (United Phosphate Company) would improve the flowability of the superabsorbent polymer in a dry batch application device under very wet conditions.

[0038] The superabsorbent polymer consists of a superabsorbent polymer starch-grafted poly(2-acrylamide-co-2-acrylic acid) and a hydrophobic material comprising a combination of soybean protein and soybean lipids. Two dry powder compositions were mixed with the superabsorbent polymer (in this case, ZEBA) and the hydrophobic material at a ratio of 30:1, and this mixture was used in planting experiments. Figure 1-4 The image shows a drying batch processing device used to apply the mixture under very humid growing conditions.

[0039] The results were unexpected. The addition of the hydrophobic material prevented the superabsorbent polymer from absorbing moisture. Initially, it was thought that the superabsorbent polymer would simply flow slightly faster, but would eventually stick to the equipment due to its reaction to moisture. Instead, the unexpected finding was that, even under moist planting conditions, this combination of materials could now be metered and applied to the soil using a dry batch processing device. For superabsorbent polymer-hydrophobic material mixtures in very moist environments, improved flow capacity through confined channels and narrow openings was observed. Regardless of any single mechanism of action, electrostatic adhesion and product bridging were mitigated or eliminated in the superabsorbent polymer mixture. Another unexpected result was that the effectiveness of the superabsorbent polymer was not compromised in the soil. Even after the first rainfall, the superabsorbent polymer-hydrophobic material mixture was still able to absorb moisture rapidly.

[0040] Figure 1The experiment, conducted in Florida under very wet spring conditions, illustrates the delivery of a dried superabsorbent polymer mixture from a hopper through a confined channel delivery pipe, where the dried mixture was applied to the roots of pine seedlings at planting time.

[0041] Figure 2 The image shows a dry, superabsorbent polymer mixture in a hopper during an experiment conducted in Florida under very humid spring conditions.

[0042] Figure 3 The experiment, conducted in very wet conditions in Florida during the spring, showed that a dry superabsorbent polymer-hydrophobic material mixture was applied to newly dug furrows and that the mixture did not absorb a large amount of moisture.

[0043] Figure 4 The image shows a dry mixture of superabsorbent polymer and hydrophobic material applied to furrows in an experiment conducted in Florida during very wet spring conditions.

[0044] Figure 5 An example of the mixed concentration and structure of a superabsorbent and hydrophobic material is shown. The mixture can be made from... Figure 6 It is made using the method shown in the flowchart.

[0045] The method may include improving the flowability of dry, superabsorbent polymers used in agricultural settings. An agricultural setting may be within a machine for on-site application, where the material is mixed immediately before being applied to furrows or ploughing furrows. The setting may also be somewhere outside the planting area, where the material is pre-mixed for sale or use by an agricultural entity. These materials may also be mixed with seeds or other nutrients or additives.

[0046] The method may include mixing a dried superabsorbent polymer with a dried hydrophobic material. In experiments, mixing improved the flowability of the dried superabsorbent polymer.

[0047] In one or more embodiments, the superabsorbent polymer includes one or a combination of starch-based polymers, starch-grafted poly(2-acrylamide-co-2-acrylic acid), xanthan gum, guar gum, hydroxyethyl carboxymethyl cellulose, carboxymethyl cellulose, polyacrylamide, and their derivatives.

[0048] Other superabsorbent polymers can be used. Furthermore, other compounds or materials, such as zeolite hyaluronic acid, humic acid, chitin / chitosan polymers, volcanic soil and volcanic ash, kelp and seaweed powder, etc., can be used for similar purposes mentioned in this invention.

[0049] In one or more embodiments, the hydrophobic material includes: i) protein powder and lipids, ii) micronized powder, iii) micronized wax, iv) calcined silica, or v) treated clay particles, and combinations thereof.

[0050] In one or more embodiments, the protein powder and lipids include one or a combination of soy protein powder, corn protein powder, oat protein powder, wheat protein powder, pea protein powder, rice protein powder, nut protein powder, seaweed protein powder, kelp protein powder, whey protein powder, casein protein powder, egg protein powder, albumin protein powder, blood meal protein powder, bone meal protein powder, fish protein powder, shellfish protein powder, plankton protein powder, yeast protein powder, bacterial protein powder, lecithin, soy lecithin, vegetable oil, fish oil, and animal fat.

[0051] In one or more embodiments, the micronized powder or micronized wax includes rice bran wax, carnauba wax, alumina, and poly(hydroxybutyrate-co-hydroxyvalerate) or a combination thereof.

[0052] In one or more embodiments, when mixed, the weight ratio of the superabsorbent polymer to the hydrophobic material is from 100:1 to 1:1000.

[0053] In one or more embodiments, the weight ratio of the superabsorbent polymer to the hydrophobic material during mixing is 1:50 to 1:200.

[0054] The following are additional experiments:

[0055] LP21007 Zeba and SpeedFLOW (hydrophobicity) ratio

[0056] The purpose of this experiment was to try various ratios of Zeba and SpeedFLOW to determine the optimal combination that ensures the mixture is flowable without hindering water absorption. Samples were prepared with various SpeedFLOW + Zeba ratios. These ratios are as follows:

[0057] Zeba itself

[0058] #1 = 1:30

[0059] #2 = 1:20

[0060] #3 = 1:70

[0061] Weigh 100g of each sample and place them in identical containers. Place these containers in a laboratory environment at approximately 25°C. Simultaneously, add 20g of water to each container. Observe the samples:

[0062] • When water is added to both #2 and #3 in parallel, #2 allows water to be injected into the sample faster than #3;

[0063] • When water was added to both Zeba and #1 in parallel, #1 seemed to absorb water faster because Zeba had water droplets on top of the sample.

[0064] Conclusion: Samples with a flow rate (SpeedFLOW) allow water to penetrate deeper into the sample. Samples with a flow rate (SpeedFLOW) also appear to absorb water slightly faster.

[0065] Weigh 2g of each sample and place them in identical containers. Place these containers in a laboratory environment at approximately 25°C. Simultaneously, add 100g of water to each container. Observe the samples:

[0066] • After 1 minute, all samples had absorbed water;

[0067] • After 5 minutes, the consistency of the samples was similar to that of applesauce;

[0068] • After 8 minutes, Zeba and #3 samples had the consistency of jelly, while #1 and #2 had the consistency of applesauce.

[0069] • After 20 minutes, Zeba and #3 samples had the consistency of jelly, while #1 and #2 had the consistency of applesauce.

[0070] • After 45 minutes, the consistency of all samples was similar to that of jelly / apple sauce;

[0071] • After 50 minutes, the consistency of all samples was similar to that of jelly / apple sauce.

[0072] Conclusion: Samples with a flow rate (SpeedFLOW) do not impede the rate of water absorption or the amount of water that can be absorbed by the sample.

[0073] Each sample was placed in a refrigerator and left for 1.5 days. The samples were then removed from the refrigerator, and 2g of each sample was weighed and placed in the same container. These containers were placed in a sealed tent, and the humidity was increased to 99% using a humidifier. As soon as the samples were placed in the tent, 120g of water was added to each sample simultaneously. The samples were difficult to see because the humidifier maintained such a high humidity level in the tent, creating a smoky atmosphere. Due to the difficulty in seeing the samples, few photos were taken. However, videos were taken periodically showing the samples being gently shaken to demonstrate sample consistency. The samples were then placed in the humid tent for approximately 2 hours and observed.

[0074] • After 1 minute, all the samples were liquid;

[0075] After 5 minutes, #1 is applesauce, #2 and #3 are watery applesauce, and Zeba is liquid;

[0076] • After 18 minutes, #1 is applesauce, #2 and #3 are watery applesauce, and Zeba is liquid;

[0077] • After 21 minutes, numbers 1-3 are apple sauce, while Zeba is liquid, but the consistency at the bottom is like apple sauce or jelly.

[0078] • After 28 minutes, numbers 1-3 are applesauce, while Zeba is a watery applesauce;

[0079] • After 33 minutes, numbers 1-3 were applesauce, while Zeba was watery applesauce;

[0080] • After 1 hour and 17 minutes, all samples were applesauce;

[0081] • After 2 hours and 8 minutes, all samples were applesauce / jelly.

[0082] The samples were then left overnight on a laboratory workbench at approximately 25°C to observe for any noticeable changes. No noticeable changes were observed. Their consistency did not appear to change overnight. The temperature remained unchanged. The viscosity of the samples after being left overnight on the laboratory workbench is as follows:

[0083] Zeba: 3120 cPs;

[0084] #1 (SpeedFLOW: Zeba@1:30) = 3670 cPs;

[0085] #2 (SpeedFLOW: Zeba@1:20) = 4560 cPs;

[0086] #3 (SpeedFLOW: Zeba@1:70) = 3600 cPs.

[0087] Conclusion: A higher flow rate does not impede the rate of water absorption or the amount of water that can be absorbed by the sample. When samples are removed from a cold environment and then placed in a high-humidity environment, samples with a higher flow rate appear to absorb water slightly faster than the Zeba itself or samples with a flow rate:Zeba ratio of 1:70. It is possible that the Zeba adheres to itself, hindering water absorption.

[0088] Weigh 1g of each sample and place it in the same container. These are environmental samples. Place the containers in a sealed tent with humidity increased to up to 90%. Leave the containers in the sealed tent for 1 minute. After 1 minute, simultaneously add 100g of water to each sample. Remove the samples from the tent and place them on a laboratory workbench at approximately 25°C. Observe and photograph the samples using the Tagarno microscope's automatic photographing function for approximately 1 hour.

[0089] • After 1 minute, all the samples were liquid;

[0090] • After 30 minutes, all samples had the consistency of applesauce;

[0091] • After 1 hour, all samples had the consistency of applesauce;

[0092] Conclusion: Samples with speedflow do not impede the rate of water absorption or the amount of water that can be absorbed by the sample. Samples with speedflow appear to have a more uniform distribution.

[0093] Note: There is indeed a tendency for the flow rate to settle. The product needs to be mixed before application. The product is prone to sedimentation during transportation.

Claims

1. A drying composition for improving the flowability of a superabsorbent polymer used in bulk planting applications in a dry agricultural environment, said composition comprising a mixture of a superabsorbent polymer and a hydrophobic material; The superabsorbent polymers mentioned above include starch-grafted poly(2-acrylamide-co-2-acrylic acid); The hydrophobic material comprises a combination of protein powder and lipids; In the mixture, the weight ratio of the superabsorbent polymer to the hydrophobic material is 30:

1.

2. The dried composition according to claim 1, wherein the protein powder comprises soy protein powder and the lipid comprises soy lecithin.

3. The dried composition according to claim 1, wherein the protein powder comprises one or a combination of soy protein powder, corn protein powder, oat protein powder, wheat protein powder, pea protein powder, rice protein powder, nut protein powder, seaweed protein powder, whey protein powder, casein protein powder, egg protein powder, blood meal protein powder, bone meal protein powder, fish protein powder, shellfish protein powder, plankton protein powder, yeast protein powder, and bacterial protein powder; and the lipid comprises one or a combination of lecithin, vegetable oil, and animal fat.

4. A method for improving the flowability of a dried superabsorbent polymer used in dry batch planting applications in an agricultural environment, the method comprising mixing the dried superabsorbent polymer with a dried hydrophobic material, wherein the mixing improves the flowability of the dried superabsorbent polymer through a confined channel of a dry batch processing device. The superabsorbent polymers mentioned above include starch-grafted poly(2-acrylamide-co-2-acrylic acid); The hydrophobic material comprises a combination of protein powder and lipids; the weight ratio of the superabsorbent polymer to the hydrophobic material is 30:

1.

5. The method according to claim 4, wherein the protein powder comprises soy protein powder and the lipid comprises soy lecithin.

6. The method according to claim 4, wherein the protein powder comprises one or a combination of soy protein powder, corn protein powder, oat protein powder, wheat protein powder, pea protein powder, rice protein powder, nut protein powder, seaweed protein powder, whey protein powder, casein protein powder, egg protein powder, blood meal protein powder, bone meal protein powder, fish protein powder, shellfish protein powder, plankton protein powder, yeast protein powder, and bacterial protein powder; and the lipid comprises one or a combination of lecithin, vegetable oil, and animal fat.

Images