AU2008261509B2

AU2008261509B2 - Suspension concentrate of Zn thiodiazole and preparation thereof

Info

Publication number: AU2008261509B2
Application number: AU2008261509A
Authority: AU
Inventors: Jingui Dai; Xianming Tong; Fanglin Wei; Danqian Xu; Qunhui Xu; Zhenyuan Xu; Guonian Zhu
Original assignee: ZHEJIANG XINNONG CHEMICAL CO Ltd; Institute of Pesticide and Environmental Toxicology of ZJU
Current assignee: ZHEJIANG XINNONG CHEMICAL CO Ltd; Institute of Pesticide and Environmental Toxicology of ZJU
Priority date: 2007-06-08
Filing date: 2008-06-05
Publication date: 2012-03-15
Anticipated expiration: 2028-06-05
Also published as: BRPI0811361A2; AU2008261509C1; EG26147A; MY157922A; CN101194611A; AU2008261509A1; WO2008151513A1; CN101194611B

Abstract

The invention provides a suspension concentrate of Zn Thiodiazole and preparation thereof. The suspension concentrate comprises Zn Thiodiazole 5-60%, wetting agent 2-8%, dispersant 2-5%, thickening agent 0-3%, antifreezing agent 0-5%, preservative agent 0-0.5%, antifoaming agent 0-0.5% and water the rest. The suspension concentrate can be prepared by grinding with sand-mill, homogenizing by high-speed shearing combined with sanding, or homogenizing by high-speed shearing combined with homogenizing by high pressure. The product possesses strong control effect for bacterial diseases, e.g. bacterial leaf-blight of rice, bacterial strips and canker of citrus. Its advantages comprise low environmental pollution, low toxicity; superior formulation property such as no precipitation or stratification when stored at room temperature for two years, long shelf life, noninflammable, and safe for storage and transportation.

Description

Description SUSPENSION CONCENTRATE OF ZN THIODIAZOLE AND PREPARATION THEREOF Field of Invention: This invention relates to a kind of fungicide. In particular, the invention relates to a suspension concentrate (SC) formulation of Zn-thiodiazole and method for its preparation. Background of the Invention: Pesticide suspension concentrate (SC) or aqueous suspension concentrate is stable suspension of water-insoluble or slightly water-soluble active ingredient using adjuvant such as wetting, dispersing agents, in an aqueous system by a high energy wet grinding processes. The SC formulation, which represents the current trend of development of formulation, is an important formulation type. The aqueous suspension concentrate comprises active ingredient, wetting agent, dispersing agent, anti-freezing agent, antiseptic agent, thickening agent, pH regulator, antifoaming agent and water. Compared with oil-base and wettable powder (WP) formulations, water-base suspension concentrate has many advantages such as: relatively low cost; safety to operators, plants and environment; mixing with water in any proportion, ease of handling and application; non-dusty and easy to measure. The novel Zn Thiodiazole compound, chemical name: 2-amino-5-thiohydroxy-1, 3, 4-thiadiazole Zn, is a novel fungicide discovered and developed by Zhejiang Xinnong Chemical CO., Ltd. and has been obtained the patent (patent No. ZL00132119.6)at home. The Zn Thiodiazole, which is a new organic Zn agricultural fungicide with high efficacy and low toxicity, can control crop bacterial diseases such as rice bacterial leaf blight, rice bacterial leaf streak and citrus canker. The SC formulation would make the novel fungicide become a high efficient, safe, economic green pesticide, and lay a good foundation for market prospect. Rice bacterial leaf blight usually occur in Zhejiang, Jiangxi, Guangdong, Guangxi, Sichuan, Hunan, Hubei, Hainan, Yunnan, Guizhou, Anhui and Jiangsu provinces(district), and the occurrence area are over 6 million hectares (90 million mu )every year; rice bacterial leaf streak usually occur in Zhejiang, Jiangxi, Fujian, Guangdong, Guangxi, Hunan, Hainan and Yunnan provinces(district), and the occurrence area are range from 4.7 to 5.3 million hectares( 70 million to 80 million mu ) every year; citrus canker usually occur in Zhejiang, Fujian, Jiangxi, Guangdong, Guangxi, Sichuan and Yunnan provinces(district), and the occurrence area are over 66.7 thousand hectares ( 10 million mu )every year.

At present, the fungicides used for controlling crop bacterial diseases in China are only agricultural streptomycin, copper fungicides and bismerthiazol, but their prevention efficiency are not high. Since agricultural streptomycin belongs to antibiotics, the pathogenic bacteria easily have resistance. It is about for 15 years, Bismerthiazol as a main fungicide against rice bacterial leaf streak, which has developed resistance, and its persistent period is only 7-10 days. Copper fungicides are good for controlling bacterial diseases in citrus and vegetable, but they can not be applied in peach, plum, apricot and Japanese apricot. In order to controlling bacterial leaf shot hole, the thiodiazole-copper was applied in peach by the researchers of Jinhua academy of agricultural sciences, Zhejiang province, as a result, most peaches presented serious fungicide injury symptoms such as leaf and fruit redden and abscission. If thiodiazole-copper is applied in large region, it will causes severe economic loss for farmers. The research technology and preparation technology about suspension concentrate (SC) are more complicated, because that technology relate to pesticide chemistry, pesticide formulation, physical chemistry, chemical machinery and so on. Compared with emulsifiable concentrate (EC) and wettable powders (WP) formulation, the popularization degree of suspension concentrate (SC) formulation, which emerged in 1970s, is limited, because SC technology is limited by the development of surfactant and grinding equipment. Most SC products especially made in China have poor physical stability including layered and settling during storage, uneven dispersing of active ingredient, caking in wrappage(the sales pack), bad dispersing and poor suspensibility in water. Therefore, the spread and use of pesticide SC formulation in agriculture is still very low. By a lot of creative work and choice of suitable components, the requirement such as physical stability of formulation, dispersing and suspensibility in water must be met when the Zn Thiodiazole SC is prepared. Summary of the Invention The present invention relates to stable Zn Thiodiazole SC formulation and method for its preparation. The Zn Thiodiazole SC can be used for efficiently controlling crop bacterial diseases such as rice bacterial leaf blight, rice bacterial leaf streak and citrus canker without resistance, and has the advantages of low cost, no dust pollution, good dispersing and good suspensibility. The above objects of this invention are achieved by the following technical means: The invention provides an aqueous SC formulation comprising, on a weight to weight basis, a) about 5 to 60% active ingredient Zn Thiodiazole; b) about 2 to 8% of one or more wetting agents, c) about 2 to 5% of one or more dispersing agents; d) 0 to about 3% of one or more thickening agents; e) 0 to about 5% of one or more 2 anti-freezing agents; f) 0 to about 0.5% of one or more antiseptic agents; g) 0 to about 0.5% of one or more antifoaming agents; and h) about 18 to 91% of water. The above-mentioned wetting agent is selected from the group consisting of EO/PO polyether block, fatty alcohol ether, fatty alcohol ethoxylate, tallow ethoxyamine hydrochloride, alkylnaphthalene sulphonate, fatty alcohol polyoxyethylene ether sulfate, and acyl-glutamate. The above-mentioned dispersing agent is selected from the group consisting of naphthalene sulfonic acid condensate sodium salt, phenol sulfonic acid condensate sodium salt, sodium methyl-Naphthalene sulfonate and formaldehyde condensation compound, sodium ligninsulfonate, dispersing agent NNO, acrylic acid homopolymer sodium salt, macromolecule polycarboxylate, sodium dioctyl sulfo succinate, EO/PO polyether block and maleic acid - acrylic acid copolymer sodium salt. The above-mentioned thickening agent is selected from the group consisting of xanthan gum, magnesium aluminum silicate, carboxymethyl cellulose sodium, sodium phosphate starch, starch sodium octenylsuccinate and polyvinyl alcohol. The above-mentioned anti-freezing agent is selected from the group consisting of glycol, propylene glycol, glycerin, isopropanol and urea. The above-mentioned antiseptic agent is selected from the group consisting of formaldehyde, salol, butyl p-hydroxybenzoate and potassium sorbate. The above-mentioned antifoaming agent is selected from silicone defoaming agent, and polyether defoaming agent. The above-mentioned water is selected from deionized water and distilled water. Furthermore, the invention provides a preparation method of Zn Thiodiazole SC, which adopts the following process of manufacturing. All components (a to h) weighed by weight are milled or homogenized using high pressure homogenizer, then the Zn Thiodiazole SC could be obtained. All the above components are milled for 30 to 120 minutes in sand milling, filtered for removing the medium, then the Zn Thiodiazole SC could be obtained. All the above components are also homogenized in high-shearing emulsifying homogenizer for 20 to 30 minutes, milled for 30 to 90 minutes or I to 3 cycles in sand milling, filtered for removing the medium; or all the components are homogenized using high pressure homogenizer; then the Zn Thiodiazole SC could be obtained. The Zn Thiodiazole of technical grade is solid, and insoluble in water. It could have excellent suspensibility in water with the presence of suitable adjuvant such as 3 dispersing agent and wetting agent. But the well physical stability of Zn Thiodiazole SC is affected by the following factors: 1) The interaction of particles causes flocculation and aggregation; 2) Ostwald ripening (Many small crystals form in a system initially but slowly disappear except for a few that grow larger, at the expense of the small crystals. The smaller crystals act as "nutrients" for the bigger crystals. As the larger crystals grow, the area around them is depleted of smaller crystals.); 3) The gravity results in layered and particle deposition. Therefore, in order to keeping well physical stability of Zn Thiodiazole SC, it is necessary to choose specific adjuvant and processing technology, which prevent accumulation and settlement of suspended matter and growth of crystal. The proportion of the composition and processing technology provided by the present invention can meet the requirements of stable Zn Thiodiazole SC in all respects during storage period. The Zn Thiodiazole SC provided by the present invention gives milk white and homogeneous appearance properties, excellent flowability properties, well dispersing properties, good suspensibility and well physical stability properties. The Zn Thiodiazole SC provided by the present invention has a suspension rate of more than 98%; and a decomposition rate of less than 5%, a milk white and homogeneous appearance, a suspension rate of more than 95% at 54±1*C for 14 days; and a homogeneous appearance and good flowability at 0 ±1*C for 7 days; a water liberation rate of less than 5%, good dispersing, a suspension rate of more than 95% after storage for two years. Compared with existing technology, Zn-thiodiazole SC and method for its preparation provided by the present invention have some benefits as followed: 1) No pollution of dust in the production and application, low health risk to producer and user; 2) Lower toxicity of preparation, better environmental compatibility and safer to human and animal because water as dispersion medium; 3) High efficacy on controlling crop bacterial diseases such as rice bacterial leaf blight, rice bacterial leaf streak and citrus canker, low residue on crop; 4) No layered and settling at room temperature after storage for two years, long shelf life; 5) High flash point, uninflammable, safe during storage and transportation. The experimental result shows no any fungicide injury, when the green environmental protection Zn Thiodiazole SC is applied on peach. The Zn Thiodiazole 4 SC can effectively resolve the problem that there is no fungicide for controlling bacterial diseases in peach and plum. It is a new fungicide product, and has obtained significant economic and social benefits, and has important significance to adjust fungicide products structure and promote technical progress in industry. The test conducted by Zhejiang academy of agricultural sciences indicates that the efficacy of 20% Zn Thiodiazole SC is superior to that of 20% Sai Sentong (N,N- metylene- di (2-amino-5-marcapto-1,3,4-thidiazol)copper) SC sold in the market, and the efficacy with the application concentration of 125ml/667m 2 is about 80.5% and 74.6%, respectively. Detailed Description of the preferred Embodiment The Zn Thiodiazole SC and method for its preparation are illustrated combining the following examples, which are given by way of illustration only, and are not limitative of the present invention. Various changes and modifications within the spirit and scope of the invention are defined in the claims. Example I All components comprising 5.0% of Zn Thiodiazole, 2.0% of tallow ethoxyamine hydrochloride, 1.0% of naphthalene sulfonic acid condensate sodium salt, 1.0% of acrylic acid homopolymer sodium salt, 0.5% of xanthan gum, 2.5% of sodium phosphate starch, 5.0% of propylene glycol, 0.5% of potassium sorbate, 0.5% of polyether defoaming agent and about 82% distilled water are milled in sand miller for 120 minutes, filtered, and 5% Zn Thiodiazole SC is obtained. Example 2 All components comprising about 15.0% of Zn-thiodiazole, 3.0% of fatty alcohol ether, 1.0% of alkylnaphthalene sulphonate, 1.0% of sodium ligninsulfonate, 1.0% of EO/PO Polyether block, 1.0% of maleic acid - acrylic acid copolymer sodium salt, 0.05% of xanthan gum, 0.6% of magnesium aluminum silicate, 2.3% of starch sodium octenylsuccinate, 2.0% of glycerin, 0.4% of salol, 0.1% of silicone defoaming agent and 72.55% of deionized water are homogenized in high-shearing emulsifying homogenizer for 20 minutes, milled for 1 to 3 cycles in sand miller, then 15% Zn Thiodiazole SC is obtained. Example 3 All components comprising 20.0% of Zn-thiodiazole, 2.0% of alkylnaphthalene sulphonate, 1.3% of fatty alcohol polyoxyethylene ether sulfate, 1.0% of phenol sulfonic acid condensate sodium salt, 2.0% of sodium methyl-Naphthalene sulfonate and formaldehyde condensation compound, 2.0% of carboxymethyl cellulose sodium, 2.0% of glycol, 0.2% of butyl p-hydroxybenzoate, 0.1% of silicone defoaming agent, 5 and 69.4% of deionized water are homogenized in high-shearing emulsifying homogenizer for 25 minutes, milled for 90 minutes in sand miller, filtered, then 20% Zn Thiodiazole SC is obtained. Example 4 All components comprising 40.0% of Zn-thiodiazole, 4.0 % of fatty alcohol ethoxylate, 1.0% of EO/PO Polyether block, 4.0% of macromolecule polycarboxylate, 0.2% of formaldehyde, 0.5% of polyvinyl alcohol, 2.0% of isopropanol, 48.3% of deionized water are homogenized in high-shearing emulsifying homogenizer for 30 minutes, milled for 1 to 3 cycles in sand miller, then 40% Zn Thiodiazole SC is obtained. Example 5 All components comprising 50.0% of Zn-thiodiazole, 3.0% of fatty alcohol ether, 1.0% of tallow ethoxyamine hydrochloride, 2.0% of acyl-glutamate, 3.0% of macromolecule polycarboxylate, 1.0% of naphthalene sulfonic acid condensate sodium salt, 1.0% of sodium dioctyl sulfo succinate, 3.0% of urea, 0.4% of silicone defoaming agent, 35.6% of deionized water are homogenized in high-shearing emulsifying homogenizer for 20 minutes, homogenized using high pressure homogenizer, then 50% Zn Thiodiazole SC is obtained. Example 6 All components comprising 60.0% of Zn-thiodiazole, 3.0 % of fatty alcohol ethoxylate, 1.0% of alkylnaphthalene sulphonate, 4.0% of fatty alcohol polyoxyethylene ether sulfate, 3.0% of phenol sulfonic acid condensate sodium salt, 1.5% of dispersing agent NNO, 0.5% of sodium methyl-Naphthalene sulfonate and formaldehyde condensation compound, 0.2% of silicone defoaming agent, 26.8% of distilled water are homogenized in high-shearing emulsifying homogenizer for 30 minutes, homogenized using high pressure homogenizer, then 60% Zn Thiodiazole SC is obtained. Experiment The Zn Thiodiazole SC provided by the present invention has good adhesiveness, good spreadability and good permeability on plant surface. The result of bioassay in the laboratory conducted in Nanjing agricultural university shows that Zn Thiodiazole SC has good control effect on rice bacterial leaf blight, and the efficacy is better than that of Ye Qingshuang (bismerthiazol). 6 The result of laboratory bioassay of the invention is showed in Table 1 Table I the biological activity of 20%Zn Thiodiazole SC to rice bacterial leaf blight (24h) Fungicides Toxicity regression LC 50 (mg/L) LC<o (mg/L) Correlation equations coefficient (R) 95%technical Zn Thiodiazole Y=4.03+1.97X 3.10 12.32 0.93 20% Zn Y=4.46+l.85X 1.96 8.56 0.99 Thiodiazole SC 95% technical bismerthiazol Y=4.78+1.05X 1.63 21.53 0.99 Through some field trials, it is found that the Zn Thiodiazole SC provided by the present invention has good control effect on bacterial diseases such as rice bacterial leaf blight, rice bacterial leaf streak and citrus canker. The results of field efficacy of Zn Thiodiazole SC are as follows: The field trials of 20% Zn Thiodiazole SC have been conducted by Ruian plant protection station, Zhejiang province, Fujian academy of agricultural sciences and Jiangxi academy of agricultural sciences, and the 20% Zn Thiodiazole SC has good control effect on bacterial diseases such as rice bacterial leaf blight, rice bacterial leaf streak and citrus canker (see Table 2, 3, 4 and 5). Table 2 the result of field efficacy of 20% Zn Thiodiazole SC to rice bacterial leaf blight (Ruian, Zhejiang province) Fungicides Dose Average efficacy at 7 days after treatment (%) 125(ml/667 m 2 ) 75.5 a A 20% Zn Thiodiazole SC 100(ml/667 M 2 ) 71.2 a A 75(ml/667 M 2 ) 46.9 b B 20% bismerthiazol WP 100(g/667 M 2 ) 43.8 c C Table 3 the result of field efficacy of 20% Zn Thiodiazole SC to rice bacterial leaf streak (Ruian, Zhejiang province) Fungicides Dose Average efficacy at 7 days after treatment (%) 7 Editorial note Case 2008261509 Page 8 has been left intentionally blank.

Table 7 the acute toxicity test of 20% Zn Thiodiazole SC Test objects Results Toxicity and risk grade Honeybee LC 5 o (mg/L)> 6000 Low toxicity, low risk Quail LD 5 o (mg/kg)> 1000 Low toxicity Zebra LC 5 o(mg/L)=5.56 Moderate toxicity Silkworm LC 5 o (mg/L)> 6000 Low toxicity, low risk 9

Claims

1. A Zn Thiodiazole suspension concentrate (SC) including, on a weight to weight basis, about 5 to 60% Zn Thiodiazole , about 2 to 8% of one or more wetting agents; about 2 to 5% of one or more dispersing agents; 0 to about 3% of one or more thickening agents; 0 to about 5% of one or more anti-freezing agents; 0 to about 0.5% of one or more antiseptic agents; 0 to 0.5% about of one or more antifoaming agents; and about 18 to 91% of water, wherein the wetting agent is selected from the group consisting of EO/PO polyether block, fatty alcohol ether, fatty alcohol ethoxylate, tallow ethoxyamine hydrochloride, alkylnaphthalene sulphonate, fatty alcohol polyoxyethylene ether sulfate, and acyl-glutamate, wherein the dispersing agent is selected from the group consisting of naphthalene sulfonic acid condensate sodium salt, phenol sulfonic acid condensate sodium salt, sodium methyl-Naphthalene sulfonate and formaldehyde condensation compound, sodium ligninsulfonate, dispersing agent NNO, acrylic acid homopolymer sodium salt, macromolecule polycarboxylate, sodium dioctyl sulfo succinate, EO/PO polyether block and maleic acid - acrylic acid copolymer sodium salt.

2. A Zn Thiodiazole suspension concentrate (SC) according to claim 1, wherein the thickening agent is selected from the group consisting of xanthan gum, magnesium aluminum silicate, carboxymethyl cellulose sodium, sodium phosphate starch, starch sodium octenylsuccinate, and polyvinyl alcohol.

3. A Zn Thiodiazole suspension concentrate (SC) according to claim 1, wherein the anti-freezing agent is selected from the group consisting of glycol, propylene glycol, glycerin, isopropanol and urea.

4. A Zn Thiodiazole suspension concentrate (SC) according to claim 1, wherein the antiseptic agent is selected from the group consisting of formaldehyde, salol, butyl p-hydroxybenzoate and potassium sorbate.

5. A Zn Thiodiazole suspension concentrate (SC) according to claim 1, wherein the antifoaming agent is selected from silicone defoaming agent and polyether defoaming agent.

6. A Zn Thiodiazole suspension concentrate (SC) according to claim 1, wherein the water is selected from deionized water and distilled water

7. A preparation method for Zn Thiodiazole SC, and the characteristics of method lies in the following process of manufacturing: All the components comprising about 5 to 60% of Zn Thiodiazole, about 2 to 8% of one or more wetting agents; about 2 to 5% of one or more dispersing agents; 0 to about 3% of one or more thickening agents; 0 to about 5% of one or more anti-freezing agents; 0 to about 0.5% of one or more antiseptic agents; 0 to about 0.5% of one or more antifoaming agents; and about 18 to 10 91% of water, weighed by weight are milled, filtered, or homogenized using high pressure homogenizer, then the Zn Thiodiazole SC could be obtained.

8. A preparation method for Zn Thiodiazole SC according to claim 7, all components are milled for 30 to 120 minutes in sand milling, filtered for removing the medium, then the Zn Thiodiazole SC could be obtained.

9. A preparation method for Zn Thiodiazole SC according to claim 7, all components are also homogenized in high-shearing emulsifying homogenizer for 20 to 30 minutes, milled in sand milling, or homogenized using high pressure homogenizer, then the Zn Thiodiazole SC could be obtained. III