A film-forming agent for a seed coating agent, its preparation method, and application

Abstract

The present invention belongs to the technical field of agriculture, and particularly relates to a film-forming agent for seed coating agents, a preparation method thereof, and an application. The film-forming agent for seed coating agents is mainly prepared by emulsion polymerization of a biological gum, a soft monomer, and a hard monomer in water; wherein, the biological gum is selected from diutan gum, guar gum or welan gum, and the mass percentages of the biological gum, the soft monomer, and the hard monomer in the raw material system are respectively: the biological gum is 0.01-0.1%, the soft monomer is 25-30%, and the hard monomer is 5-15%. The film-forming agent for seed coating agents provided by the present invention selects a specific biological gum to crosslink the copolymer formed by the copolymerization of the soft and hard monomers, and the obtained film-forming agent has excellent film-forming property and swelling rate, and shows better adhesion and coating uniformity when applied to seed coating agents, thereby further improving the coating quality of the seed coating agents.

Description

Technical Field

[0001] The present invention belongs to the technical field of agriculture, and specifically relates to a film-forming agent for seed coating agents, a preparation method thereof, and an application thereof. Background Art

[0002] A seed coating agent is a compound preparation for coating crop seeds or other plant seeds, having a film-forming property. The seed coating agent can solidify on the seed surface to form a film of the seed coating. The seed coating absorbs water and swells in the soil without being dissolved, allowing the water and oxygen required for the normal germination of the seeds to pass through, and slowly releasing the contained pesticides, seed fertilizers and other substances.

[0003] In agricultural production, the seeds of most crops take root and germinate in the soil after sowing. However, due to the gnawing and damage of harmful insects and microorganisms in the soil to the seeds, the germination rate of the seeds is reduced. Therefore, the use of seed coating agents can largely protect the seeds from being damaged, effectively prevent and control the diseases and pests from seed germination to the seedling stage, ensure the smooth germination of plant seeds, promote the healthy growth and development of seedlings, and improve the seed germination rate.

[0004] The film-forming agent is a key auxiliary agent of the seed coating agent, which is closely related to the important performance indicators of the seed coating agent such as uniformity, shedding rate and germination rate. The effect of the film-forming agent determines the coating performance and safety performance of the seed coating agent. In existing seed coating agents, pure acrylic emulsion is often used as the film-forming agent. For example, the Chinese invention patent with the publication number CN104054744B discloses a suspension seed coating agent with the active ingredients of thiamethoxam and difenoconazole, which includes a pesticide active ingredient, a wetting and dispersing agent, a film-forming agent, a coloring agent, an antifoaming agent, a thickening agent and water. The film-forming agent is generally substances such as pure acrylic emulsion. When the pure acrylic emulsion is used as the film-forming agent of the seed coating agent, it has good performance in terms of suspension rate, low-temperature stability, high-temperature stability, coating germination rate, etc., but its adhesion and coating uniformity need to be further improved. Summary of the Invention

[0005] The purpose of the present invention is to provide a film-forming agent for seed coating agents to solve the problems of the adhesion and coating uniformity that need to be improved when the pure acrylic emulsion film-forming agent is applied in the seed coating agent.

[0006] The second purpose of the present invention is to provide a preparation method of the above film-forming agent for seed coating agents to solve the above problems.

[0007] The third purpose of the present invention is to provide the application of the above film-forming agent in the seed coating agent to solve the problems of the adhesion and coating uniformity of the existing seed coating agents that need to be improved.

[0008] In order to achieve the above purposes, the technical solutions adopted by the present invention are as follows:

[0009] A film-forming agent for seed coating agents, wherein the film-forming agent for seed coating agents is mainly prepared by emulsion polymerization of a biological gum, a soft monomer, and a hard monomer in water; among them, the biological gum is selected from diutan gum, guar gum or welan gum, and the mass ratios of the biological gum, the soft monomer, and the hard monomer in the raw material system are respectively: biological gum 0.01-0.1%, soft monomer 25-30%, hard monomer 5-15%.

[0010] The film-forming agent for seed coating agents provided by the present invention selects a specific biological gum to crosslink the copolymer formed by the copolymerization of the soft and hard monomers. The obtained film-forming agent has excellent film-forming properties and swelling rate, and shows better adhesion and coating uniformity when applied to seed coating agents, thereby further improving the coating quality of the seed coating agents.

[0011] Preferably, the soft monomer is an alkyl acrylate, and the number of carbon atoms of the alkyl ester in the alkyl acrylate is 2-8. Using the above soft monomer has a lower cost, and the obtained product shows good performance in terms of stability, film-forming property, drying speed, dissolution rate, and swelling rate. Further preferably, the soft monomer is ethyl acrylate, butyl acrylate or octyl acrylate.

[0012] Preferably, the hard monomer is selected from any one of methyl methacrylate, diethyl maleate, acrylic acid, and acrylamide. Using the above hard monomer, the copolymer formed after copolymerization with the soft monomer has appropriate hardness and softness, and can further optimize the indexes such as the stability, film-forming property, drying speed, dissolution rate, swelling rate, and coating safety of the product.

[0013] To further improve indexes such as the mechanical stability and dilution stability of the film-forming agent, preferably, the emulsifier used in the emulsion polymerization consists of an anionic emulsifier and a non-ionic emulsifier; the mass ratio of the anionic emulsifier to the non-ionic emulsifier is 1:1-2. Considering the emulsifier cost and emulsification effect comprehensively, preferably, the anionic emulsifier is any one of sodium dodecyl sulfate, calcium dodecylbenzenesulfonate, and sodium dodecyl sulfonate; the non-ionic emulsifier is any one of styrylphenol polyoxyethylene ether, polyoxyethylene sorbitan fatty acid ester, isomeric alcohol and ethylene oxide condensate, castor oil and ethylene oxide condensate, and allyl alcohol and ethylene oxide condensate.

[0014] In the present invention, the raw material system consists of a biological glue, a soft monomer, a hard monomer, an emulsifier, an initiator, and water. Among them, the biological glue, the soft monomer, and the hard monomer are the main components. The emulsifier plays a role in maintaining the stability of the emulsion polymerization system, and the initiator initiates the emulsion polymerization reaction. Preferably, the raw material system consists of the following components in weight percentage: 0.01 - 0.1% of biological glue, 25 - 30% of soft monomer, 5 - 15% of hard monomer, 0.5 - 1% of emulsifier, 0.03 - 0.4% of initiator, and the balance is water. Reacting with the above ratio, a film-forming agent with excellent properties such as stability, water resistance, swelling ratio, viscosity, drying speed, film-forming property, and safety can be obtained.

[0015] More preferably, the raw material system consists of the following components in weight percentage: 0.03 - 0.08% of biological glue, 25 - 30% of soft monomer, 5 - 15% of hard monomer, 0.5 - 0.6% of emulsifier, 0.3 - 0.4% of initiator, and the balance is water. Adopting this formulation system, the cooperation between raw materials is better, the dosage of each raw material is appropriate, and the comprehensive cost performance of the product is the best.

[0016] A preparation method of a film-forming agent for a seed coating agent includes the following steps: mixing and dispersing a soft monomer, a hard monomer, an aqueous solution of biological glue, and an aqueous solution of emulsifier to obtain a pre-emulsion, and then adding an initiator to react.

[0017] In the preparation method of the film-forming agent for a seed coating agent of the present invention, the biological glue is mixed into the system together with the soft and hard monomers before emulsion polymerization, and crosslinking occurs during polymerization (polymerization method). Compared with the preparation method of first polymerizing and then crosslinking (blending method), the obtained product has better physical stability and lower dissolution rate, showing better comprehensive performance.

[0018] The application of the above film-forming agent in a seed coating agent.

[0019] When applied to a seed coating agent, the film-forming agent of the biological glue of the present invention can be used to replace the film-forming agent in the seed coating agent. After replacement, the adhesion and coating uniformity of the corresponding seed coating agent are significantly improved, and the indexes such as suspension rate, low-temperature stability, high-temperature stability, and germination rate do not decrease or are improved to a certain extent. Description of the Drawings

[0020] Figure 1 It is a process flow chart for processing the film-forming agent of the present invention;

[0021] Figure 2 It is a processing device diagram of the present invention;

[0022] Among them, 1 - digital display stirrer; 2 - constant pressure dropping funnel; 3 - spherical condenser; 4 - peristaltic pump connector; 5 - thermometer; 6 - three-necked flask; 7 - constant temperature water bath. Detailed Description of the Invention

[0023] In view of the deficiencies of existing bioadhesive products when used in seed coating agents, such as poor adhesion and uneven coating, the present invention provides a film-forming agent containing a bioadhesive. By utilizing the cross-linking effect of the bioadhesive on the copolymer formed by the copolymerization of soft and hard monomers, a film-forming agent with excellent performance in multiple aspects such as stability, water resistance, swelling ratio, viscosity, drying speed, film-forming property, and safety is prepared, and its use effect is verified in the seed coating agent.

[0024] The seed coating agent of the present invention is made from the following raw materials by mass percentage: bioadhesive 0.01 - 0.1%, soft monomer 25 - 30%, hard monomer 5 - 15%, emulsifier 0.5 - 1%, initiator 0.03 - 0.4%, and the balance is water. In the present invention, unless otherwise specified, "%" all refers to mass percentage.

[0025] The principle of preparing the bioadhesive in the present invention is as follows: Using water as the reaction medium, the soft monomer and the hard monomer are added with an initiator in the micelles formed by the emulsifier and then carry out copolymerization reaction. The copolymers are cross-linked with each other under the action of the bioadhesive to obtain the film-forming agent. In the present invention, the influence of two addition methods of the bioadhesive on the performance of the prepared film-forming agent is investigated.

[0026] The emulsifier and the initiator are auxiliaries used in the emulsion polymerization process. The emulsifier is used to adjust the physical stability of the system, such as mechanical stability, dilution stability, etc. The initiator can be selected from one or more of potassium persulfate, performic acid, and benzoyl peroxide.

[0027] The process flow chart of the film-forming agent of the present invention is as Figure 1 shown, and the processing device diagram used is as Figure 2 shown, including a digital display stirrer 1, a constant pressure dropping funnel 2, a spherical condenser 3, a peristaltic pump connector 4, a thermometer 5, a three-necked flask 6, and a constant temperature water bath 7. The processing method of the film-forming agent mainly includes the following steps:

[0028] (1) Prepare an aqueous solution of the emulsifier and an aqueous solution of the bioadhesive, stir with a glass rod until all are dissolved, then place the aqueous solution of the emulsifier and the aqueous solution of the bioadhesive in a 250 mL three-necked flask equipped with a stirring device, and then add the soft monomer and the hard monomer to this four-necked flask. Stir at 300 - 350 r / min at room temperature for 60 - 90 min to obtain a stable and non-stratified uniform milky white pre-emulsion.

[0029] (2) Raise the temperature to 78 - 80 °C, use a peristaltic pump to dropwise add an aqueous solution of the initiator (5% - 10%), keep the temperature between 78 - 80 °C, keep the stirring speed at 250 - 300 r / min, and maintain the aqueous solution of the initiator to be added dropwise within 2.5 h - 3.5 h.

[0030] (3) After the dropping is completed, the stirring speed is maintained at 200 - 250 r / min, the temperature of the reaction solution is raised to 80 - 85 °C and kept warm for 50 - 60 min, then it is naturally cooled to below 30 °C, and filtered through a 200-mesh filter cloth for discharging.

[0031] The performance tests of the bioadhesive film-forming agent of the present invention include items such as stability, water resistance, swelling ratio, viscosity, drying speed, film-forming property, safety, etc., and are specifically described as follows:

[0032] 1. Determination of physical properties of the film-forming agent

[0033] 1.1 Determination of the stability of the film-forming agent

[0034] Mechanical stability: Take an appropriate amount of the filtered film-forming agent sample and put it into a centrifuge tube, and spin it strongly at a speed of 5000 r / min for 20 min with a high-speed centrifuge. Observe. If there is no phenomenon such as stratification or precipitation in the film-forming agent, it means that the mechanical stability of the film-forming agent is good, and + is used to indicate that the emulsion stability passes; - is used to indicate that the emulsion stability fails.

[0035] Dilution stability: Take an appropriate amount of the film-forming agent product and dilute it about 10 times, stir it evenly and place it in a test tube, seal it with plastic wrap, and let it stand at room temperature for 72 h. Observe. If there is no phenomenon such as stratification or demulsification in the film-forming agent, it means that the dilution stability of the film-forming agent is good, and + is used to indicate that the emulsion stability passes; - is used to indicate that the emulsion stability fails.

[0036] 1.2 Viscosity determination

[0037] After shaking the sample to be tested evenly, place it in a constant temperature water bath. After the temperature of the sample reaches 25 °C, take about 400 mL of the sample to be tested and put it into a beaker, and let it stand in a 25 °C constant temperature water bath for 1 h. Adjust the viscometer to be normal, install the rotor, adjust the rotor speed to (30 ± 1) r / min, then slowly insert the rotor into the sample so that the liquid level just submerges the groove on the rotor, start the engine, and immediately read the viscosity value (mPa·s) after 1 min. If the viscosity value is greater than 1000 mPa·s, it is regarded as unsuitable.

[0038] 2. Detection of film-forming effect

[0039] 2.1 Determination of film-forming property

[0040] The film-forming agent is formed into a film on a 2 × 10 cm glass plate, and the film thickness is 0.08 mm. The film-forming property is investigated in three grades. Uniform film formation, and after soaking in water for 0.5 h after film formation, if the film can be scraped off the glass plate completely, it is grade I; uniform film formation, and after soaking the glass plate in water for 0.5 h, if the film cannot be scraped off the glass plate completely, it is grade II; if the film-forming agent cannot form a film on the glass plate, it is grade III.

[0041] 2.2 Determination of drying speed

[0042] After diluting 1 g of the film-forming agent 10 times, take 1 g of the diluted solution and coat the seeds at a ratio of 1:50 (mass ratio). Then dry them at 40 °C until constant weight, and measure the time required to reach constant weight.

[0043] 3.3 Determination of dissolution rate (water resistance)

[0044] Weigh approximately 1 portion of the film-forming agent accurately in advance, form a film continuously on a 2 × 15 cm glass plate, and weigh the weight of the dried film W after drying. o , put it into a petri dish with a diameter of 15 cm containing 2 / 3 water, soak for 18 hours, then take it out and dry it, and weigh the remaining mass of the film-forming agent W t , the higher the dissolution rate, the worse the surface water resistance.

[0045]

[0046] In the formula:

[0047] W o — Weight of the dried film, (g);

[0048] W t — Weight of the soaked film, (g);

[0049] 3.4 Determination of swelling rate (water permeability)

[0050] Weigh approximately 1 g of the film-forming agent, form a film continuously on a 2 × 15 cm glass plate, and weigh the dry film weight W1 after drying. Immerse it in a petri dish with a diameter of 15 cm containing 2 / 3 water, soak for 6 hours, then take it out, drain the water, and weigh the wet film weight W2. The higher the swelling rate, the better the water permeability effect.

[0051]

[0052] In the formula:

[0053] W1— Weight of the dry film, (g);

[0054] W2— Weight of the wet film, (g);

[0055] 3.5 Safety test (testing the germination rate of seed coating)

[0056] Use an aqueous solution of the film-forming agent at 4% (based on the final product of the film-forming agent) to coat wheat seeds in an amount of 2% of the seed mass, and dry them naturally at room temperature. Incubate them in a petri dish with a diameter of 12 cm at 25 °C under humid conditions. Use only blank dressing as a control (add the same amount of clear water as the medicament as the control treatment group for seed germination), record the germination process, investigate the growth of the crops at 3 days and 7 days respectively, and calculate the germination rate. To determine the safety of the film-forming agent for wheat.

[0057] The technical solution of the present invention will be further described below in conjunction with specific embodiments. In the following embodiments, the main specifications of the raw materials used are shown in Tables 1 to 4.

[0058] Table 1 Raw materials for bioadhesive

[0059]

[0060]

[0061] Table 2 Raw materials for soft monomer

[0062]

[0063] Table 3 Raw materials for hard monomer

[0064]

[0065] Table 4 Raw materials for emulsifier

[0066]

[0067] I. Specific embodiments of the film-forming agent for seed coating agent of the present invention and its preparation method

[0068] Example 1

[0069] The film-forming agent for seed coating agent in this example is mainly prepared by emulsion polymerization of bioadhesive, soft monomer and hard monomer in water. The composition of the raw material system by mass percentage is: 0.06% of Dingyou glue, 30% of ethyl acrylate, 15% of methyl methacrylate, 0.2% of sodium dodecyl sulfate, 0.4% of castor oil and ethylene oxide condensate, 0.3% of potassium persulfate, and the balance is water.

[0070] The preparation method of the film-forming agent for seed coating agent in this example includes the following steps:

[0071] (1) Prepare an aqueous solution of emulsifier and an aqueous solution of bioadhesive, stir with a glass rod until all are dissolved, then place the aqueous solution of emulsifier and the aqueous solution of bioadhesive in a 250 mL three-necked flask equipped with a stirring device, and then add the soft monomer and hard monomer to this four-necked flask. Stir at 350 r / min at room temperature for 90 min to obtain a stable and non-layered uniform milky white pre-emulsion.

[0072] (2) Raise the temperature to 78 °C, dropwise add the aqueous solution of initiator with a peristaltic pump, keep the temperature at 78 °C, and keep the stirring speed at 250 r / min, and maintain the aqueous solution of initiator to be dropped within 3 h.

[0073] (3) After the dropping is completed, keep the stirring speed at 200 r / min, raise the temperature of the reaction solution to 80 °C and keep it warm for 60 min, then naturally cool it to below 30 °C, and filter the product with a 200-mesh filter cloth.

[0074] Example 2

[0075] For the film-forming agent for the seed coating agent in this example, DY glue is also used as the biological glue, and the formulation differences from that in Example 1 are listed in Table 5.

[0076] Table 5 Formulation of the film-forming agent based on DY glue in Example 1 and Example 2

[0077]

[0078]

[0079] Examples 3 - 4

[0080] For the film-forming agent for the seed coating agent in Examples 3 - 4, guar gum is used as the biological glue, and its formulation is listed in Table 6.

[0081] Table 6 Formulation of the film-forming agent based on guar gum in Example 3 and Example 4

[0082]

[0083] Examples 5 - 6

[0084] For the film-forming agent for the seed coating agent in Examples 5 - 6, welan gum is used as the biological glue, and its formulation is listed in Table 7.

[0085] Table 7 Formulation of the film-forming agent based on welan gum in Example 5 and Example 6

[0086]

[0087]

[0088] The film-forming agents in Examples 2 - 6 above are all prepared according to the method in Example 1.

[0089] II. Comparative Examples

[0090] Comparative Example 1

[0091] This comparative example illustrates the performance of film-forming agents with different biological glues. The formulations of the film-forming agents with different biological glues are shown in Table 8, and the preparation methods are all carried out according to Example 1.

[0092] Table 8 Formulations of film-forming agents containing different biological glues

[0093]

[0094] The performance of the film-forming agents with different biological glues is shown in Table 9.

[0095] Table 9 Performance of film-forming agents with different biological glues

[0096]

[0097]

[0098] As can be seen from the experimental results in Table 9, Samples 2#, 3#, and 5# are relatively stable. Based on the 1# formulation, diutan gum, guar gum, and welan gum are suitable as raw materials for the bioadhesive film-forming agent, with a higher swelling rate and better film-forming properties, and each index reaches the required effect. However, gellan gum has a certain impact on the physical stability of the system, and the swelling rate of pullulan is relatively low, which is not conducive to plant germination.

[0099] The formulation design with different dosages of bioadhesive is shown in Table 10.

[0100] Table 10 Formulation Screening Table for Bioadhesive Dosage

[0101]

[0102] The performance of the film-forming agent with different dosages of bioadhesive is shown in Table 11.

[0103] Table 11 Performance of Film-Forming Agents with Different Dosages of Bioadhesive

[0104]

[0105] As can be seen from the experimental results in Table 11, when the dosage of diutan gum is 0.005%, the swelling rate is small, while when the dosage is 0.12%, the drying speed is slow and the dissolution rate is high, which is not suitable. When the dosage of guar gum is 0.005%, the swelling rate is small, while when the dosage is 0.12%, the viscosity is too high and it is not conducive to production. When the dosage of welan gum is 0.005%, the swelling rate is small and the experimental effect is not achieved, while when the dosage is 0.12%, the viscosity is too high and the stability is poor. The experimental results show that when the dosage of each bioadhesive is within 0.01 - 0.10%, each index reaches the required effect.

[0106] Comparative Example 2

[0107] This comparative example illustrates the influence of monomer dosage on the performance of the film-forming agent. The differences in monomer dosages of each formulation are shown in Table 12, and the method for preparing the film-forming agent using each formulation is carried out according to Example 1.

[0108] Table 12 Formulation Description of Different Monomer Dosages

[0109]

[0110] The performance of the film-forming agent with different monomer dosages is shown in Table 13.

[0111] Table 13 Performance of Film-Forming Agents with Different Monomer Dosages

[0112]

[0113] As can be seen from the experimental results in Table 13, when the dosage of the soft monomer is 25-30%, the film-forming effect is better. When it is less than 25%, the film-forming property is poor. When it is greater than 30%, the drying speed is slow. When the dosage of the hard monomer is 5-15%, the film-forming effect is better. When it is less than 5%, the drying speed is slow. When it is greater than 15%, the film-forming property is poor.

[0114] Comparative Example 3

[0115] This comparative example describes the selection of the emulsifier and the experimental process. The formulation designs of different emulsifiers are shown in Table 14, and the performance test results of the film-forming agents with different emulsifiers are shown in Table 15.

[0116] Table 14 Formulation Designs of Different Emulsifiers

[0117]

[0118] Table 15 Performance Test Results of Film-Forming Agents with Different Emulsifiers

[0119]

[0120] As can be seen from the experimental results, the emulsifier formulations of styrylphenol polyoxyethylene ether, polyoxyethylene sorbitan fatty acid ester, isomeric alcohol and ethylene oxide condensate, castor oil and ethylene oxide condensate, and allyl alcohol and ethylene oxide condensate are stable.

[0121] Based on the above experimental results, adjust the mass ratio of the anionic emulsifier to the non-ionic emulsifier to 1:1-2, and at the same time control the dosage of the emulsifier at 0.5-1%, such as 0.5%, 0.8%, 1%, etc., and the stability experimental results basically consistent with those of Example 1 can be achieved.

[0122] The initiator can be selected from one or more of potassium persulfate, performic acid, and benzoyl peroxide. Its dosage can be determined according to the type of the initiator, and it only needs to meet the requirements of general emulsion polymerization. Its dosage is generally 0.03-0.4%.

[0123] Comparative Example 4

[0124] This comparative example illustrates the influence of different reaction methods of the bioadhesive on the performance of the obtained film-forming agent. The formulations of different bioadhesives are listed in Table 16, and the corresponding performance performances of the film-forming agents are listed in Table 17.

[0125] Table 16 Formulation Designs of Different Bioadhesives

[0126]

[0127] When producing the film-forming agent using the formulation in Table 16, two methods are used. One is the polymerization method of Example 1, and the other is the blending method. The implementation process of the blending method is as follows:

[0128] (1) Prepare aqueous solutions of sodium dodecyl sulfate and polyoxyethylene sorbitan fatty acid ester respectively, stir them with a glass rod until completely dissolved, then place the aqueous solution of the emulsifier in a 250 mL four-necked flask equipped with a stirring device, and add ethyl acrylate and methyl methacrylate to the four-necked flask. Stir at 350 r / min for 90 min at room temperature to obtain a stable and non-layered uniform milky white pre-emulsion.

[0129] (2) Raise the temperature to 78 °C, and use a peristaltic pump to dropwise add an aqueous solution of potassium persulfate. Keep the reaction temperature at 78 °C, continuously stir at 250 r / min, and maintain the dropwise addition of the aqueous solution of potassium persulfate within 3 h.

[0130] (3) After the dropwise addition is completed, raise the temperature of the reaction solution to 80 °C and keep it warm for 60 min, continuously stir at 200 r / min, and finally cool naturally to below 30 °C, and filter the product with a 200-mesh filter cloth.

[0131] (4) Prepare an aqueous solution of biological glue (concentration: 6%), add it to the prepared emulsion, and use a high-shear emulsifier at 8000 r / min for continuous shearing for 30 min to obtain a film-forming agent.

[0132] It can be seen that the main difference between the blending method and the polymerization method lies in the addition timing of the aqueous solution of biological glue. The blending method adds it after polymerization.

[0133] Table 17 Performance of film-forming agents with different reaction methods of biological glue

[0134]

[0135] From the experimental results in Table 17, it can be seen that when using the blending method, the physical stability of the film-forming agent becomes worse and the dissolution rate increases. The polymerization method obviously has better physical stability and all indicators are better than those of the blending method. Therefore, it is more appropriate to use the polymerization method as the processing technology for the film-forming agent containing biological glue.

[0136] III. Experimental examples

[0137] 1. Test results of the performance of the film-forming agents in Examples 1 to 6

[0138] The test results of the performance of the film-forming agents in Examples 1 to 6 are shown in Table 18.

[0139] Table 18 Test results of the performance of the film-forming agents in Examples 1 to 6

[0140]

[0141] From the results in Table 18, it can be seen that the samples in each example are relatively stable and all indicators reach the required effects.

[0142] The results of the coating safety experiment of the film-forming agents in Examples 1 to 6 are shown in Table 19. Among them, the CK group is the 1# formula in Table 8.

[0143] Table 19 Safety Test of Film-Forming Agents in Examples 1 to 6 (Seed Coating Germination Rate Test)

[0144]

[0145]

[0146] From the experimental results in Table 19, it can be seen that the film-forming agents in Examples 1 to 6 have good safety and can meet the requirements of seed germination.

[0147] 2. Application of Film-Forming Agent in Seed Coating Agent

[0148] In addition to the active ingredients, seed coating agents generally also contain components such as dispersants, thickeners, preservatives, film-forming agents, antifreeze agents, pigments, defoamers, etc. The film-forming agent of the present invention can be used to replace the film-forming agent in the original seed coating agent formula, so as to exert the excellent performance of the film-forming agent of the present invention.

[0149] In this experimental example, the prepared bioadhesive film-forming agent was used to replace the film-forming agent in the seed coating agent. After making the finished product, the suspension rate, low-temperature stability, heat storage stability, coating uniformity, coating shedding rate and coating safety of the seed coating agent were detected.

[0150] The detection methods for each item are as follows:

[0151] ① Determination of Suspension Rate

[0152] Weigh two portions of 50 g each of the prepared seed coating agents, namely A and B, with a difference less than 0.1 g, accurate to 0.02 g, and place them in two 200 mL beakers. Add 50 mL of standard hard water at 30°C ± 2°C to each beaker. Make a circular motion by hand at a speed of 120 r / min for 2 min. Then transfer the suspension to a 250 mL graduated cylinder respectively, and wash the residue into the graduated cylinder three times with 100 mL of standard hard water at 30°C ± 2°C. Dilute to the scale with standard hard water at 30°C ± 2°C, cover with a stopper, and with the bottom of the graduated cylinder as the axis, invert the graduated cylinder 30 times up and down within 1 min. For sample A, immediately use a pipette to transfer 9 / 10 (i.e., 225 mL) of the suspension from the content within 10 s - 15 s, ensuring that the top of the pipette is always a few millimeters below the liquid surface. Transfer the 25 mL suspension at the bottom of the graduated cylinder to a 100 mL beaker that has been dried to constant weight. Remove water in a constant temperature water bath at 80°C - 90°C until it is about 2 mL, add 1 mL of ethanol, and continue to remove water in the water bath until it reaches constant weight. Weigh the mass of the residue m1 (accurate to 0.002 g).

[0153] Open the stopper of the graduated cylinder for Specimen B, then vertically place it in a thermostatic water bath without vibration, avoiding direct sunlight, and let it stand for 30 min. Use a pipette to remove 9 / 10 (i.e., 225 mL) of the suspension within 10 s to 15 s, without shaking or disturbing the sediment in the graduated cylinder, ensuring that the tip of the pipette is always a few millimeters below the liquid surface. Treat the 25 mL residue at the bottom of the graduated cylinder in the same way as for Specimen A to obtain the residue mass m2.

[0154] The suspension rate ω (%) of the specimen is calculated by the following formula.

[0155]

[0156] In the formula:

[0157] m1—the mass of the suspension agent remaining at the bottom of Cylinder A after evaporation to constant weight in 25 mL, in grams (g);

[0158] m2—the mass of the suspension agent remaining at the bottom of Cylinder B after evaporation to constant weight in 25 mL, in grams (g).

[0159] ② Low-temperature stability test

[0160] Take 100 mL of the prepared seed coating agent and add it to a centrifuge tube. Cool it to (0 ± 2) °C in a refrigerator, and keep the centrifuge tube and its contents at (0 ± 2) °C for 1 h, stirring it every 15 min for 15 s each time, and observe whether there is any change in appearance. Put the centrifuge tube back into the refrigerator and continue to place it at (0 ± 2) °C for 7 d. Restore it to room temperature and observe whether the product can flow freely, without bottom settlement, without pasting, and without lumps. If so, it is qualified; otherwise, it is unqualified.

[0161] ③ Heat storage stability test

[0162] Use a syringe to inject about 30 mL of the prepared seed coating agent into a clean ampoule bottle (avoiding the specimen contacting the bottleneck). Place this ampoule bottle in an ice-salt bath for cooling, and quickly seal it with a high-temperature flame (avoiding solvent evaporation). Seal at least 3 bottles, cool to room temperature and weigh. Place the sealed ampoule bottles in a metal container, then put the metal container into a constant temperature oven at 54 ± 2 °C for 14 d. Take it out and cool to room temperature, wipe the outside of the ampoule bottle clean, and weigh them separately. For the specimens with unchanged mass, observe the stability of the product. The product is qualified if it can flow freely, without bottom settlement, without pasting, and without lumps.

[0163] ④ Determination of product use adhesion

[0164] Using the prepared seed coating agent, weigh 50 g of peanut seeds (accurate to 1 g) into a petri dish, transfer 0.3 g of the sample into the petri dish, cover it and shake for 5 min, then remove the lid and let it stand for 20 min. Weigh two portions of 10 g (accurate to 0.002 g) of the seeds respectively and place them in Erlenmeyer flasks. To one portion, accurately add 100 mL of ethanol solution, stopper it and place it in an ultrasonic cleaner and shake for 10 min to fully dissolve the seed coating agent on the surface of the seeds. Take it out and let it stand for 10 min or centrifuge it, and take 10 mL of the supernatant into a 50 mL volumetric flask, dilute it to the mark with ethanol solution, and shake well to obtain Solution A.

[0165] Place the other portion in a shaker and shake for 10 min, then transfer the seeds to another Erlenmeyer flask, and obtain Solution B according to the treatment method of Solution A.

[0166] Using the ethanol solution as a reference, measure its absorbance at a wavelength of 350 nm.

[0167] The adhesion X7 is calculated according to the formula:

[0168]

[0169] In the formula:

[0170] m0—the mass of the coated seeds weighed for preparing Solution A, g;

[0171] m1—the mass of the coated seeds weighed for preparing Solution B, g;

[0172] A0—the absorbance of Solution A;

[0173] A1—the absorbance of Solution B.

[0174] ⑤ Determination of the coating uniformity of the product

[0175] Using the prepared seed coating agent, coat wheat seeds in an amount of 2% of the seed mass and dry them naturally at room temperature. Randomly measure 20 coated seeds and place them in 20 stoppered centrifuge tubes (4 seeds in each tube) respectively. Use a pipette to accurately add 2.0 mL - 5.0 mL (the absorbance is within the linear range) of ethanol solution to each tube, cover it, soak for 1 h, shake and extract for 15 min, and let it stand or centrifuge to obtain a clear solution. Using the ethanol solution as a reference, measure its absorbance A at the maximum absorption wavelength. Arrange the measured 20 absorbance data from smallest to largest, and calculate the average absorbance value Aa. The coating uniformity X of the sample is calculated according to the following formula.

[0176]

[0177] In the formula: n—the number of centrifuge tubes with absorbance in the range of 0.7Aa - 1.3Aa.

[0178] ⑥ Product Use Safety Test (Seed Coating Germination Rate Test)

[0179] Use the prepared seed coating agent to coat wheat seeds at a rate of 2% of the seed quality and dry them naturally at room temperature. Incubate them in a petri dish with a diameter of 12 cm at 25°C under humid conditions. Use only blank seed dressing as a control (add the same amount of clear water as the medicament as the control treatment group for seed germination), record the germination process, investigate the crop growth situation at 3 days and 7 days respectively, calculate the germination rate, and determine the safety of the film-forming agent for wheat.

[0180] 2.1 Film-Forming Agent Applicability Test of 9% Thiamethoxam·Fludioxonil·Tebuconazole Seed Coating Agent

[0181] Add the film-forming agents of Examples 1-6 to the 9% thiamethoxam·fludioxonil·tebuconazole seed coating agent. The 9% thiamethoxam·fludioxonil·tebuconazole seed coating agent contains thiamethoxam, fludioxonil, and tebuconazole at 7.6%, 0.7%, and 0.7% respectively. The film-forming agent in the original formula uses a pure acrylic solution with a dosage of 4%. Detect the technical indicators of the seed coating agent, and the results are shown in Tables 20-22.

[0182] Table 20 Film-Forming Agent Applicability Test of 9% Thiamethoxam·Fludioxonil·Tebuconazole Seed Coating Agent

[0183]

[0184] Table 21 Detection Results of Film-Forming Agent Quality Performance of 9% Thiamethoxam·Fludioxonil·Tebuconazole Seed Coating Agent

[0185]

[0186]

[0187] Table 22 Film-Forming Agent Safety Test of 9% Thiamethoxam·Fludioxonil·Tebuconazole Seed Coating Agent (Seed Coating Germination Rate Test)

[0188]

[0189] It can be seen from the experimental results that the seed coating agent samples are stable, and the adhesion and coating uniformity are significantly improved compared with the pure acrylic emulsion. It meets the required effects for each index, has a good coating effect, and is safe for seeds.

[0190] 2.2 Film-Forming Agent Applicability Test of 25% Thiamethoxam·Fludioxonil·Metalaxyl-M Seed Coating Agent

[0191] Add the film-forming agents of Examples 1-6 to the 25% thiamethoxam·fludioxonil·metalaxyl-M seed coating agent (CK is the addition of pure acrylic emulsion). The 25% thiamethoxam·fludioxonil·metalaxyl-M seed coating agent contains thiamethoxam, fludioxonil, and metalaxyl-M at 22.2%, 1.1%, and 1.7% respectively. The film-forming agent in the original formula uses a pure acrylic solution with a dosage of 4%. Detect the technical indicators of the seed coating agent as shown in Tables 23-25.

[0192] Table 23 Film-forming agent applicability test of 25% thiamethoxam·fludioxonil·metalaxyl seed coating agent

[0193]

[0194] Table 24 Test results of film-forming agent quality performance of 25% thiamethoxam·fludioxonil·metalaxyl seed coating agent

[0195]

[0196] Table 25 Film-forming agent safety test of 25% thiamethoxam·fludioxonil·metalaxyl seed coating agent (seed coating germination rate test)

[0197]

[0198] It can be seen from the experimental results that the film-forming agents of the examples also have significant improvements in terms of adhesion and coating uniformity, and other indicators do not decrease or have a certain degree of improvement. Generally speaking, the developed film-forming agents have good overall use effects on 25% thiamethoxam·fludioxonil·metalaxyl seed coating agent.

[0199] 2.3 Film-forming agent applicability test of 600g / L imidacloprid seed coating agent

[0200] Add the film-forming agents of Examples 1-6 to 600g / L imidacloprid seed coating agent (CK is pure acrylic emulsion added). The imidacloprid content in 600g / L imidacloprid seed coating agent is 600g / L, and the film-forming agent in the original formula uses pure acrylic solution with a dosage of 4%. The technical indicators of the seed coating agent are shown in Tables 26-28.

[0201] Table 26 Film-forming agent applicability test of 600g / L imidacloprid seed coating agent

[0202]

[0203] Table 27 Test results of film-forming agent quality performance of 600g / L imidacloprid seed coating agent

[0204]

[0205] Table 28 Film-forming agent safety test of 600g / L imidacloprid seed coating agent (seed coating germination rate test)

[0206]

[0207]

[0208] It can be seen from the experimental results that the seed coating agent sample is stable, each index reaches the required effect, the coating effect is good, the adhesion and coating uniformity are significantly improved, and it is safe for seeds. Generally speaking, the film-forming agent of the present invention has an overall good use effect on the 600 g / L imidacloprid seed coating agent.

Claims

1. A film-forming agent for seed coating agent, characterized in that, The film-forming agent for the seed coating agent is mainly prepared by emulsion polymerization of a biological glue, a soft monomer, and a hard monomer in water; among them, the biological glue is selected from diutan gum, guar gum, or welan gum, and the mass percentages of the biological glue, the soft monomer, and the hard monomer in the raw material system are respectively: biological glue 0.01-0.1%, soft monomer 25-30%, hard monomer 5-15%; the soft monomer is an alkyl acrylate, and the number of carbon atoms of the alkyl ester in the alkyl acrylate is 2-8; the hard monomer is selected from any one of methyl methacrylate, diethyl maleate, acrylic acid, and acrylamide.

2. The film-forming agent for seed coating agent according to claim 1, characterized in that, The soft monomer is ethyl acrylate, butyl acrylate, or octyl acrylate.

3. The film-forming agent for seed coating agent according to claim 1, characterized in that, The emulsifier used in the emulsion polymerization consists of an anionic emulsifier and a non-ionic emulsifier; the mass ratio of the anionic emulsifier to the non-ionic emulsifier is 1:1-2.

4. The film-forming agent for seed coating agent according to claim 3, characterized in that, The anionic emulsifier is any one of sodium dodecyl sulfate, calcium dodecylbenzenesulfonate, and sodium dodecyl sulfonate; the non-ionic emulsifier is any one of styrenyl phenol polyoxyethylene ether, polyoxyethylene sorbitan fatty acid ester, isomeric alcohol and ethylene oxide condensate, castor oil and ethylene oxide condensate, and allyl alcohol and ethylene oxide condensate.

5. The film-forming agent for seed coating agent according to any one of claims 1 to 4, characterized in that The raw material system consists of the following components in weight percentages: biological glue 0.01-0.1%, soft monomer 25-30%, hard monomer 5-15%, emulsifier 0.5-1%, initiator 0.03-0.4%, and the balance is water.

6. The film-forming agent for seed coating agent according to claim 5, characterized in that, The raw material system consists of the following components in weight percentages: biological glue 0.03-0.08%, soft monomer 25-30%, hard monomer 5-15%, emulsifier 0.5-0.6%, initiator 0.3-0.4%, and the balance is water.

7. A preparation method of the film-forming agent for seed coating agent according to any one of claims 1 to 6, characterized in that, It includes the following steps: Mix and disperse the soft monomer, hard monomer, aqueous solution of biological glue, and aqueous solution of emulsifier to obtain a pre-emulsion, and then add an initiator to react.

8. The application of a film-forming agent according to any one of claims 1 to 6 in a seed coating agent.

Images