A water-emulsifiable paste for controlling resistant grass weeds in rice fields and a preparation method thereof

Abstract

The embodiment of the present invention discloses a water-emulsifiable paste for preventing and controlling resistant grass weeds in rice fields and a preparation method thereof. The paste comprises, by weight percentage: 1-4% Tolpyralate, 12.5-50% Diquat, 3-5% Cloquintocet-mexyl, 10-30% emulsifier, 5-10% dispersant, 0.1-0.5% defoamer, and the remainder is a carrier; wherein the mass ratio of Tolpyralate, Diquat and Cloquintocet-mexyl is 1.8-2.1:24-26:3-5. The paste provided by the present invention can effectively prevent and control resistant grass weeds in rice fields, is safe for rice, and has a very high market value, so as to solve the problems of poor safety, waste of resources, harm to the environment, and incomplete weed killing encountered by existing agents in the process of preventing and controlling resistant grass weeds in rice fields.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of pesticides, and in particular to a water-emulsifiable paste for controlling resistant gramineous weeds in rice fields and a preparation method thereof. Background Art

[0002] Tolpyralate is a triketone herbicide, with the test code SL-573 and the molecular formula C 21 H 28 N2O9S, relative molecular mass 484.52, CAS number: 1101132-67-5. Chemical name: 1-({1-ethyl-4-[(2-methyl-3-methoxyethoxy-4-methylsulfonyl)benzoyl]-1H-pyrazol-5-yl}oxy)ethyl methyl carbonate. Its mechanism of action is to inhibit p-hydroxyphenylpyruvate dioxygenase (HPPD), which ultimately affects the biosynthesis of carotenoids in plants. Since corn absorbs Tolpyralate slowly and can quickly degrade Tolpyralate into inactive compounds through 4-hydroxylation, Tolpyralate is highly safe for corn. However, rice has a weak ability to metabolize Tolpyralate, and spraying Tolpyralate on stems and leaves can easily cause phytotoxicity to rice.

[0003] Dipyridamole is an amide contact herbicide that is almost not transmitted in the plant body. It is used to control barnyard grass in rice fields by stem and leaf spraying. Currently, the reported dosage forms include emulsifiable concentrates, dispersible oil suspensions, water-dispersible granules, and suspension concentrates. However, emulsifiable concentrates and dispersible oil suspensions contain a large amount of organic solvents, and the processing and use processes bring serious harm to manufacturers and users, and cause soil and water pollution, damaging the ecological environment. Water-dispersible granules and suspension concentrates have poor efficacy and have not been accepted by the market. In addition, since dipyridamole does not have systemic transmission activity, weeds are very likely to rebound after application, resulting in incomplete weed death and easy recurrence.

[0004] Paste refers to a water-based paste containing active ingredients that can form a film and is generally used directly. The dosage form code is "PA", and it is usually called a paste if it is coagulated but not solid. Patent CN201410117869.4 discloses a pesticide paste for controlling longhorn beetles. The above-mentioned paste can only be used directly, and cannot be emulsified and dispersed after adding water, and cannot meet the requirements of pesticide spraying.

[0005] At present, due to the continuous use of a single herbicide in rice fields, it is increasingly difficult to control resistant grass weeds such as resistant barnyard grass, resistant lycopodiella, and resistant crabgrass in rice fields. Weed resistance in rice fields has attracted extensive attention from people in the industry. Therefore, it is of great significance to develop a water-emulsifiable paste for controlling resistant grass weeds in rice fields. Summary of the invention

[0006] To this end, the embodiments of the present invention provide a water-emulsifiable paste for controlling resistant grass weeds in rice fields and a preparation method thereof, so as to solve the problems of poor safety, waste of resources, harm to the environment, and incomplete weed killing encountered by existing agents in the process of controlling resistant grass weeds in rice fields.

[0007] In order to achieve the above purpose, the embodiment of the present invention provides the following technical solutions:

[0008] According to a first aspect of an embodiment of the present invention, an embodiment of the present invention provides a water-emulsifiable paste for controlling resistant grass weeds in rice fields, wherein the paste comprises, by weight percentage: 1-4% Tolpyralate, 12.5-50% Diquat, 3-5% Cloquintocet-mexyl, 10-30% emulsifier, 5-10% dispersant, 0.1-0.5% defoamer, and the remainder is a carrier, wherein the mass ratio of Tolpyralate, Diquat and Cloquintocet-mexyl is 1.8-2.1:24-26:3-5.

[0009] The inventors have found through extensive research that the ointment provided by using Tolpyralate and propanil as active ingredients and clofodine-mexyl as a safener under the above dosage ratio has excellent stability and water dispersibility, and at the same time, when the application method of stem and leaf spraying is adopted, it has excellent safety and efficacy to rice, which not only solves the problem of Tolpyralate's phytotoxicity to rice when spraying stems and leaves, but also solves the problems of propanil's efficacy and environmental protection not being taken into account and the incomplete weed death after application. In some preferred embodiments, the mass ratio of Tolpyralate, propanil and clofodine-mexyl is 2:25:3-5.

[0010] Furthermore, the emulsifier is composed of triethanolamine dodecylbenzenesulfonate, EO / PO block copolymer and castor oil polyoxyethylene ether in a mass ratio of 1.8-2.2:0.8-1.2:0.8-1.2. Studies have found that the above emulsifier can improve the control performance of the paste on resistant grass weeds in rice fields while ensuring the dispersion stability of the paste. In some preferred embodiments, the mass ratio of triethanolamine dodecylbenzenesulfonate, EO / PO block copolymer and castor oil polyoxyethylene ether is 2:1:1.

[0011] Furthermore, the EO / PO block copolymer is EthylanNS-500LQ, Atlas TM G-5000 or Termul5500.

[0012] Furthermore, the amount of ethylene oxide in the castor oil polyoxyethylene ether is 25-40.

[0013] Furthermore, the castor oil polyoxyethylene ether is Emulson CO-25, Emulson CO-30, Emulson CO-36 or Emulson CO-40.

[0014] Furthermore, the dispersant is naphthalenesulfonate dispersant Morwet D-425, Morwet D-400 or Supragil MNS / 90.

[0015] Furthermore, the defoaming agent is a silicone defoaming agent Sag1522 or Sag1572.

[0016] Furthermore, the carrier is fumed silica, precipitated silica, kaolin or attapulgite.

[0017] According to a second aspect of the embodiments of the present invention, the embodiments of the present invention provide a method for preparing the ointment as described in any one of the above items, comprising the following steps:

[0018] Tolpyralate, propanil, cloquintocet-mexyl and a dispersant are added into a mixing kettle and mixed evenly, and then ground into a first particle size by a jet mill to obtain a material A;

[0019] Add the material A into a shearing kettle, add an emulsifier, a defoamer and a carrier, and shear evenly to obtain material B;

[0020] The material B is ground to the second particle size by a rubber grinder to obtain the paste.

[0021] Furthermore, the median particle size of the first particle size / the second particle size is 2-10 microns.

[0022] The embodiments of the present invention have the following advantages:

[0023] 1. The ointment provided by the present invention has good stability, can be quickly emulsified and dispersed after entering water, and will not have floating oil, precipitation and the like after being placed for a long time, so that the drug solution spray is more uniform, which is conducive to the efficacy of the drug, and reduces the drug damage to rice, and has high safety.

[0024] 2. Compared with traditional emulsifiable concentrates and dispersible oil suspensions, the ointment provided by the present invention does not contain organic solvents, thereby reducing environmental pollution and waste of resources caused by solvents; compared with suspensions and water-dispersible granules, it has better efficacy and very high market value. DETAILED DESCRIPTION

[0025] The following specific embodiments illustrate the embodiments of the present invention. People familiar with the technology can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. Obviously, the described embodiments are part of the embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. In the following embodiments and comparative examples, unless otherwise specified, all percentages are weight percentages.

[0026] Example 1

[0027] The present embodiment provides an ointment, the raw materials of which are: Tolpyralate 2%, propanil 25%, cloquintocet-mexyl 4%, emulsifier 30%, Morwet D-400 5%, Sag1522 0.1%, precipitated silica 5%, and attapulgite as the balance, wherein the emulsifier is composed of triethanolamine dodecylbenzenesulfonate, Termul 5500 and Emulson CO-25 in a mass ratio of 2:1:1.

[0028] The preparation method of the above-mentioned ointment comprises:

[0029] Tolpyralate, propanil, cloquintocet-mexyl and a dispersant are added to a mixing kettle and mixed evenly, and then crushed to a first particle size (median particle size is 2-10 microns) by a jet mill to obtain material A; material A is added to a shearing kettle, an emulsifier, a defoamer and a carrier are added, and sheared evenly to obtain material B; material B is ground to a second particle size (median particle size is 2-10 microns) by a rubber mill to obtain an ointment.

[0030] The preparation methods of the following examples and comparative examples are the same as those of Example 1.

[0031] Example 2

[0032] The present embodiment provides an ointment, the raw materials of which are: Tolpyralate 2%, propanil 25%, cloquintocet-mexyl 3%, emulsifier 30%, Morwet D-4255%, Sag15220.1%, fumed silica 5%, and attapulgite as the balance; wherein the emulsifier is composed of triethanolamine dodecylbenzenesulfonate, Ethylan NS-500LQ and Emulson CO-40 in a mass ratio of 2:1:1.

[0033] Example 3

[0034] The present embodiment provides an ointment, the raw materials of which are: Tolpyralate 2%, propanil 25%, cloquintocet-mexyl 5%, emulsifier 15%, Morwet D-400 5%, Sag1522 0.1%, fumed silica 5%, attapulgite balance, wherein the emulsifier is triethanolamine dodecylbenzenesulfonate, Atlas TM G-5000 and Emulson CO-36 are composed in a mass ratio of 2:1:1.

[0035] Example 4

[0036] The present embodiment provides an ointment, wherein the raw materials are: Tolpyralate 2%, propanil 25%, cloquintocet-mexyl 4%, emulsifier 10%, Supragil MNS / 90 5%, Sag1572 0.1%, precipitated silica 5%, attapulgite balance, wherein the emulsifier is triethanolamine dodecylbenzenesulfonate and Atlas TM G-5000 is composed by mass ratio of 2:1.

[0037] Example 5

[0038] The present embodiment provides an ointment, the raw materials of which are: Tolpyralate 2%, propanil 25%, cloquintocet-mexyl 5%, emulsifier 15%, Morwet D-400 5%, Sag1522 0.1%, fumed silica 5%, attapulgite balance, wherein the emulsifier is triethanolamine dodecylbenzenesulfonate, Atlas TM G-5000 and Emulson CO-36 are composed in a mass ratio of 1:1:1.

[0039] Comparative Example 1

[0040] The comparative example provides an ointment, the raw materials of which are: 2% of Tolpyralate, 25% of propanil, 1% of cloquintocet-mexyl, 30% of emulsifier, 5% of Morwet D-400, 0.1% of Sag1522, 5% of precipitated silica, and the balance of attapulgite, wherein the emulsifier is composed of triethanolamine dodecylbenzenesulfonate, Termul 5500 and Emulson CO-25 in a mass ratio of 2:1:1.

[0041] Comparative Example 2

[0042] The comparative example provides an ointment, whose raw materials are: 2% of Tolpyralate, 25% of propanil, 2% of cloquintocet-mexyl, 30% of emulsifier, 5% of Morwet D-400, 0.1% of Sag1522, 5% of precipitated silica, and the balance of attapulgite, wherein the emulsifier is composed of triethanolamine dodecylbenzenesulfonate, Termul 5500 and Emulson CO-25 in a mass ratio of 2:1:1.

[0043] Comparative Example 3

[0044] The comparative example provides an ointment, the raw materials of which are: 2% of Tolpyralate, 25% of propanil, 6% of cloquintocet-mexyl, 30% of emulsifier, 5% of Morwet D-400, 0.1% of Sag1522, 5% of precipitated silica, and the balance of attapulgite, wherein the emulsifier is composed of triethanolamine dodecylbenzenesulfonate, Termul 5500 and Emulson CO-25 in a mass ratio of 2:1:1.

[0045] Comparative Example 4

[0046] The comparative example provides an ointment, the raw materials of which are: 2% of Tolpyralate, 25% of propanil, 8% of cloquintocet-mexyl, 30% of a compound emulsifier, 5% of Morwet D-400, 0.1% of Sag1522, 5% of precipitated silica, and the balance of attapulgite, wherein the emulsifier is composed of triethanolamine dodecylbenzenesulfonate, Termul 5500 and Emulson CO-25 in a mass ratio of 2:1:1.

[0047] Comparative Example 5

[0048] The comparative example provides an ointment, the raw materials of which are: 2% of Tolpyralate, 25% of propanil, 10% of cloquintocet-mexyl, 30% of emulsifier, 5% of Morwet D-400, 0.1% of Sag1522, 5% of precipitated silica, and the balance of attapulgite, wherein the emulsifier is composed of triethanolamine dodecylbenzenesulfonate, Termul 5500 and Emulson CO-25 in a mass ratio of 2:1:1.

[0049] Comparative Example 6

[0050] This comparative example provides an ointment, which differs from Example 1 only in that the safener is different and an equal amount of ciprosulfamide is used to replace cloquintocet-mexyl in this comparative example.

[0051] Comparative Example 7

[0052] This comparative example provides an ointment, which differs from Example 1 only in that the safener is different, and an equal amount of fenthiocarb is used to replace clofodine-mexyl in this comparative example.

[0053] Comparative Example 8

[0054] This comparative example provides an ointment, which differs from Example 1 only in that the safener is different. In this comparative example, an equal amount of isoxadifen is used to replace cloquintocet-mexyl.

[0055] Comparative Example 9

[0056] This comparative example provides an ointment, which differs from Example 1 only in that the safener is different. In this comparative example, an equal amount of pyraclostrobin is used to replace cloquintocet-mexyl.

[0057] Comparative Example 10

[0058] The comparative example provides a paste, the raw materials of which are: 2% of Tolpyralate, 25% of propanil, 30% of emulsifier, 5% of Morwet D-400, 0.1% of Sag, 5% of precipitated silica, and the balance of attapulgite, wherein the emulsifier is composed of triethanolamine dodecylbenzenesulfonate: Termul 5500: Emulson CO-25 in a mass ratio of 2:1:1.

[0059] Test Case

[0060] 1. Stability performance test

[0061] Weigh 500 grams of samples of Examples 1-5 respectively, add them into high-barrier bottles and seal them, place them in a 54°C thermostat, and detect the mass fractions of Tolpyralate, propanil, and cloquintocet-mexyl in the samples before and after hot storage by a high-performance liquid chromatograph after 14 days; detect the pH values ​​of the samples before and after hot storage by a pH meter; detect the viscosity of the samples before and after hot storage by a rotary viscometer, and calculate the hot storage decomposition rates of Tolpyralate, propanil, and cloquintocet-mexyl according to the mass fractions of Tolpyralate, propanil, and cloquintocet-mexyl in the samples before and after hot storage. The test results are shown in Tables 1 and 2.

[0062] Table 1

[0063]

[0064] Table 2

[0065]

[0066]

[0067] The results show that the viscosity and pH value of the samples of Examples 1-5 of the present invention did not change significantly before and after heat storage, and the decomposition rates of the three active ingredients of Tolpyralate, Propanil and Cloquintocet-mexyl after heat storage were all less than 5%. The above content shows that the ointment provided by the present invention has excellent stability.

[0068] 2. Physical and chemical index test

[0069] Weigh 1 gram of each sample of Examples 1-5 and Comparative Examples 1-5, add them into 100 ml of 30°C, 342 mg / L standard hard water, stir gently with a glass rod, observe the dispersibility of the samples, pour the dispersed liquid into a centrifuge tube and place it in a 30°C constant temperature water bath. After standing for 1 hour and 24 hours, record the volume of the precipitate and the floating oil, respectively.

[0070] At the same time, 80% propanil water dispersible granules (commercially available), 34% propanil emulsifiable concentrate (commercially available), 15% Tolpyralate suspension (homemade), and 15% Tolpyralate dispersible oil suspension (homemade) were used, and the precipitation and floating oil volumes were recorded in the same way. The results are shown in Table 3.

[0071] 15% Tolpyralate suspension and 15% Tolpyralate dispersible oil suspension can be prepared according to conventional methods in the art. As an example, the preparation method of 15% Tolpyralate suspension is: Tolpyralate 15%, wetting agent Genapol X060 1%, phosphate dispersant EMULSONAG TRST 5%, ethylene glycol 5%, magnesium aluminum silicate 1%, defoamer SAG630 0.2%, Kathon 0.1%, xanthan gum 0.2%, water in appropriate amount, the above components are sheared evenly, ground by a sand mill to a material particle size D90 ≤ 5 microns, and Tolpyralate is adjusted to 15%, so as to obtain 15% Tolpyralate suspension.

[0072] The preparation method of 15% Tolpyralate dispersible oil suspension is as follows: Tolpyralate 15%, agricultural milk 500# 9%, Tween 80 7%, organic bentonite 1.5%, and the balance is methylated soybean oil. The above components are sheared evenly and ground with a sand mill until the material particle size D90 is ≤5 microns to obtain 15% Tolpyralate dispersible oil suspension.

[0073] Table 3 Dispersion stability test results

[0074]

[0075]

[0076] The results show that the ointments of Examples 1-5 of the present invention have good dispersibility and are very stable after being diluted with water. There is basically no floating oil and precipitation after being left for 24 hours. Among them, Examples 1-3 are better. However, the commercially available products have a large amount of precipitation 24 hours after dilution, and some products have floating oil.

[0077] 3. Field efficacy and safety tests

[0078] Test agent: the ointment of Examples 1-5.

[0079] Comparative Examples: the ointment of Comparative Examples 1-10, 80% propanil water dispersible granules, 34% propanil emulsifiable concentrate, 15% Tolpyralate suspension concentrate, and 15% Tolpyralate dispersible oil suspension concentrate.

[0080] Trial date: July 6, 2021

[0081] Test location: Funan, Anhui

[0082] Planting method: direct-seeding rice, rice 4-leaf stage.

[0083] Targets of control: Resistant barnyard grass, resistant Leptochloa chinensis, and resistant Digitaria sanguinalis.

[0084] Test method: Select fields with uniform distribution of resistant grass weeds and uniform rice growth. No stem and leaf herbicides were used in the test season. Each treatment area was 100 m2, with three replicates. The spraying method was to use a backpack electric sprayer for uniform spraying, without repeated spraying or missing spraying. The growth of rice was observed 7 days after the application of the drug, and the death of weeds was observed 14 days after the application of the drug. The safety of each agent on rice and the control effect on resistant grass weeds were compared. The results are shown in Table 4.

[0085] Table 4 Safety and efficacy results

[0086]

[0087]

[0088] The pastes of Examples 1-5 have good control effects on resistant barnyard grass, resistant lycopodiella, and resistant crabgrass 14 days and 21 days after application, and the agents are safe for rice; the pastes of Comparative Examples 1-2 have good control effects on resistant barnyard grass, resistant lycopodiella, and resistant crabgrass 14 days and 21 days after application, but a small amount of whitening occurs on rice leaves; the pastes of Comparative Examples 3-5 are safe for rice, but the control effect is reduced to a certain extent compared with Examples 1-5; the pastes of Comparative Examples 6-9 have good control effects on resistant barnyard grass, resistant lycopodiella, and resistant crabgrass 14 days and 21 days after application , but the rice leaves have a small amount of whitening or yellowing phenomenon; Comparative Example 10 and Tolpyralate, diazinon and the combination of the two agents purchased from the market and made by themselves without a safener are relatively poor in safety to rice. The control effect on the above three resistant grass weeds is about 90% 14 days after the application, but the control effect on the above three grass weeds drops to about 50% 21 days after the application, which means that the use of Tolpyralate or diazinon alone can achieve a good control effect on the above three resistant grass weeds two weeks after the application, but the weeds are not killed thoroughly, and after a period of time, the weeds will continue to grow and rebound. The paste provided by the present invention is safe for rice, and can achieve good control effects on resistant barnyard grass, resistant lycopodiella chinensis and resistant crabgrass 14 days and 21 days after the application.

[0089] Although the present invention has been described in detail above by general description and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements can be made to the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all belong to the scope of protection claimed by the present invention.

Claims

1. A water-emulsifiable paste for controlling resistant grass weeds in rice fields, characterized in that: The ointment comprises, by weight percentage, 1-4% of Tolpyralate, 12.5-50% of propanil, 3-5% of clofonet-mexyl, 10-30% of emulsifier, 5-10% of dispersant, 0.1-0.5% of defoamer, and the balance is carrier; wherein the mass ratio of Tolpyralate, propanil and clofonet-mexyl is 1.8-2.1:24-26:3-5.

2. The paste according to claim 1, characterized in that The emulsifier consists of triethanolamine dodecylbenzenesulfonate, EO / PO block copolymer and castor oil polyoxyethylene ether in a mass ratio of 1.8-2.2:0.8-1.2:0.8-1.

2.

3. The paste according to claim 2, characterized in that The EO / PO block copolymer is Ethylan NS-500LQ, Atlas TM G-5000 or Termul 5500.

4. The paste according to claim 2, characterized in that The amount of ethylene oxide in the castor oil polyoxyethylene ether is 25-40.

5. The paste according to claim 4, characterized in that The castor oil polyoxyethylene ether is Emulson CO-25, Emulson CO-30, Emulson CO-36 or Emulson CO-40.

6. The paste according to claim 1, characterized in that The dispersant is naphthalenesulfonate dispersant Morwet D-425, Morwet D-400 or Supragil MNS / 90.

7. The paste according to claim 1, characterized in that The defoaming agent is a polysilicone defoaming agent Sag1522 or Sag1572.

8. The paste according to claim 1, characterized in that The carrier is fumed silica, precipitated silica, kaolin or attapulgite.

9. The method for preparing the ointment according to any one of claims 1 to 8, characterized in that: The steps include: Tolpyralate, propanil, cloquintocet-mexyl and a dispersant are added into a mixing kettle and mixed evenly, and then ground into a first particle size by a jet mill to obtain a material A; Add the material A into a shearing kettle, add an emulsifier, a defoamer and a carrier, and shear evenly to obtain material B; The material B is ground to the second particle size by a rubber grinder to obtain the paste.

10. The preparation method according to claim 9, characterized in that: The median particle size of the first particle size is 2-10 microns, and the median particle size of the second particle size is 2-10 microns.

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