JPH0257042B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a dispersant for agricultural and horticultural granules. More specifically, the present invention relates to a dispersant for agricultural and horticultural granules having excellent hardness and disintegration and spreading properties in water. In recent years, the safety of pesticides has become more important.
As pesticides become less toxic and poorly water-soluble pesticide active ingredients are developed, there is an increasing need for excellent dispersibility in water to achieve efficacy. In addition, it is becoming increasingly difficult to obtain high-quality carriers with good caking strength and water swelling properties, especially high-quality bentonite. carriers are being forced to be used. Under these circumstances, conventionally, sodium ligninsulfonate, sodium alkylbenzenesulfonate, acrylic acid polymers, copolymers of acrylic acid and acrylic acid methyl ester, and maleic acid polymers described in Japanese Patent Publication No. 1501/1983 have been used. Copolymers of acid and styrene have been used as dispersants or binders for agricultural and horticultural granules. However, agricultural and horticultural granules containing these do not have sufficient cohesive strength, and as a result, the granules tend to disintegrate and become powder during the granule manufacturing process and transportation, reducing the product value. There was a problem. Additionally, if a water-soluble thickener such as methylcellulose or polyvinyl alcohol is used in combination to strengthen the caking force, the disintegration and spreadability in water will be significantly reduced, resulting in the problem that the efficacy of the agricultural chemical ingredient cannot be fully expressed. It was hot. The present inventors have made extensive studies aimed at solving these problems, and as a result, have arrived at the present invention. That is, the present invention provides maleic acid (salt) (a), styrenes (b)
and (meth)acrylic acid alkyl ester (however, the number of carbon atoms in the alkyl group is 2 to 20). A dispersant for agricultural and horticultural granules. (Meth)acrylic acid alkyl ester (however, the number of carbon atoms in the alkyl group is 2 to 20) (c), which is a constituent unit of the copolymer, is a straight chain or branched alkyl group having 2 to 20 carbon atoms. an alkyl group,
For example, ethyl group, butyl group, octyl group, 2-
Examples include ethylhexyl group, nonyl group, dodecyl group, tridecyl group, octadecyl group, and eicosyl group. Among these, preferred is carbon number 8
~18 alkyl groups. If an alkyl group with a carbon number of 2 or more is not used, the caking effect will be poor and the granules will easily disintegrate, and if the carbon number is more than 20, it will be economically difficult to obtain and not practical. Specific examples of the (meth)acrylic acid alkyl ester (c) include (meth)acrylic acid butyl ester, (meth)acrylic acid 2-ethylhexyl ester, (meth)acrylic acid lauryl ester, and (meth)acrylic acid C ₁₁ . _{13.15 Ziegler} alcohol ester, etc. Maleic acid (salts) (referring to maleic acid and/or maleic acid salts) (a) include alkali metal salts (Na, K, etc.), ammonium salts, amine salts (alkanolamines such as monoethanolamine, heterocyclic amines such as morpholine, etc.). Preferred among the salts are alkali metal salts. Maleic acid (salt) (a) preferably has a degree of neutralization of maleic acid of 85 to 100.
%belongs to. Examples of the styrenes (b) include styrene and α-alkylstyrene, such as α-methylstyrene. Other non-porous monomers (e) which can be used as structural units if necessary in the present invention include the following. (1) Hydrophilic unsaturated monomer 1 Other monoethylenically unsaturated carboxylic acid (salt)
Monomer: Monoethylenically unsaturated carboxylic acid (salt) such as (meth)acrylic acid (salt), crotonic acid (salt),
Itaconic acid (salt) etc. 2 Monoethylenically unsaturated sulfonic acid (salt) monomer: Aliphatic or aromatic monoethylenically unsaturated sulfonic acid (salt) such as vinyl sulfone (salt), styrene sulfonic acid (salt), (meth)acrylic sulfonic acid (salt) etc. 3 Monoethylenically unsaturated alcohol monomer:
(methanoallyl alcohol, etc.) 4 Polyol ester monomer of monoethylenically unsaturated carboxylic acid: hydroxyethyl (meth)
acrylate etc. (2) Weakly hydrophilic unsaturated monomer 1 Monoethylenically unsaturated amide monomer (meth)acrylamide, N-methyl (meth)
such as acrylamide. 2 Ester monomer of monoethylenically unsaturated alcohol: vinyl acetate, etc. 3 Monoethylenically unsaturated nitrile monomer: (meth)acrylonitrile, etc. 4 Monoethylenically unsaturated ether monomer: vinyl ethyl ether, vinyl isobutyl ether, etc. Among these, preferred are methacrylic acid (salt), styrene sulfonic acid (salt) and acrylonitrile. In the copolymer, the molar ratio of styrene (b) to maleic acid (salt) (a) is usually 0.2 to 0.9, preferably 0.5 to 0.8. When the molar ratio is less than 0.2, the cohesive strength of the granules decreases and they tend to disintegrate; when the molar ratio is greater than 0.9, the disintegration and spreadability of the granules in water tends to decrease. In the copolymer, the molar ratio of methacrylic acid alkyl ester (c) to maleic acid (salt) (a) is usually 0.05 to 0.5, preferably 0.1 to 0.4. When the molar ratio is less than 0.05, the cohesive strength of the granules tends to decrease, and when it is greater than 0.5, the disintegration and spreading properties of the granules in water tend to decrease. In the present invention, the above monomer is used as a copolymer.
Addition of methyl methacrylate (d) in addition to (a), (b), and (c) further improves the cohesive strength and medium disintegration spreadability of the granules. Maleic acid (salt) of methyl methacrylate (d) (a)
The molar ratio to is usually 0.05 to 0.5, preferably
It is 0.2-0.4. The molar ratio of styrenes (b) and (meth)acrylates [(c) and (d)] is usually 1:0.1 to 1:5, preferably 1:0.2 to 1:0.8. The molar ratio of (meth)acrylic acid alkyl ester (c) and methyl methacrylate (d) is usually 1:0 to
The ratio is 1:4, preferably 1:0.5 to 1:3. The molar ratio of (a) to [the sum of (b), (c) and (d)] is usually 1:0.3 to 1:3, preferably 1:1 to 1:1.5. The molar ratio of other unsaturated monomers to maleic acid (salt) (a) is usually 0 to 0.5, preferably 0 to 0.2 in the case of hydrophilic unsaturated monomers. If it is larger than 0.5, the cohesive strength of the granules tends to decrease. In the case of weakly hydrophilic unsaturated monomers, it is usually 0 to 0.4, preferably 0 to 0.2. If it is greater than 0.5, the disintegration and spreadability of the granules in water tends to decrease. The molar content of maleic acid (salt) (a) in the copolymer is usually 35 to 75 mol%, preferably 40 to 60 mol%.
It is. A specific example of a copolymer is maleic acid (Na salt)
- Copolymer _{of styrene-methacrylic acid C 11.13.15 Ziegler} alcohol ester (molar _ratio 1:0.8:0.2): maleic acid (Na salt) - styrene-methacrylic acid lauryl ester (molar ratio 1:0.7:0.3) Copolymer of maleic acid (Na salt ₎ - styrene - medacrylic acid _C12.13 Ziegler alcohol ester -
Methyl methacrylate (molar ratio 1:0.75:0.1:
0.25) copolymer; maleic acid (Na salt) - styrene - methacrylic acid 2-ethylhexyl ester -
Methyl methacrylate (molar ratio 1:0.6:0.15:
Examples include copolymers of 0.3). The copolymer of the present invention is prepared by combining (a), (b), (c), (d) and, if necessary, (e) in the presence of a conventional polymerization initiator such as a peroxide type, azo type, or redox type. 40～
It can be obtained by polymerizing at 150°C, preferably 80 to 135°C, and examples of polymerization methods include bulk polymerization and solution polymerization. In the polymerization, maleic anhydride is used as (a) and can be hydrolyzed to form maleic acid (salt). Further, when a maleate salt is used as (a), it may be made into a salt after polymerization using maleic acid, or it may be polymerized using a maleate salt. The copolymer is water-soluble or water-dispersible. Its molecular weight is usually 1000-200000, preferably
5000-50000. The dispersant for agricultural and horticultural granules of the present invention contains the above-mentioned polymer, and in addition to the copolymer, other components such as other unsaturated carboxylic acid (ester) polymers (as disclosed in Japanese Patent Publication No. 1501/1983) (such as those listed above) and auxiliary agents such as binders (sodium lignin sulfonate, polyethylene glycol, etc.), penetrants (sodium dioctyl sulfosuccinate, etc.), and dispersants (polyoxyethylene alkyl phenyl ether, etc.). Can be done. The dispersant of the present invention can be made into granules for agricultural and horticultural use together with an agricultural chemical raw material and a carrier. As the pesticide active ingredient, [herbicides such as 2,4,6 trichlorophenyl-4-nitrophenol (generic name CNP),
2-chloro-2',6'-diethyl-N-(butoxymethyl)acetanilide (butachlor), etc.;
Insecticides such as 0,0-dimethyl-S-(N-methylcarbamoylmethyl)diothiphosphate (dimethoate), 3,5-xylyl-N-methylcarbamate (XMC); Fungicides such as 3-
Allyloxy-1,2-benziisothiazole-
active ingredients of pesticides such as 1,1-dioxide (probenazole)]. Examples of carriers include bentonite, clay, talc, kaolin, calcium carbonate, and diatomaceous earth. Others described in US Pat. No. 4,129,485 can also be used. The quantitative ratio of each ingredient in agricultural and horticultural granules is usually within the following range, and is such that the total is 100%. Pesticide raw material 1 to 30% by weight Carrier 60 to 98% by weight Copolymer in the present invention 0.1 to 10% by weight Other unsaturated carboxylic acid (ester) polymer 0 to 5% by weight Auxiliary agent 0 to 5% by weight Agriculture and horticulture The method for producing granules may be the same as the conventional method, for example, the above-mentioned components are mixed in any order, and water (usually 5 to 25 %, preferably 12 to 20%) to form a wet powder or paste, which is then granulated using an extrusion type or rolling type granulator, and dried. Agricultural and horticultural granules of desired particle size can be obtained by sieving using a sifter or the like. The dispersant for agricultural and horticultural granules of the present invention has excellent cohesive strength and disintegration and spreading properties in water, and has excellent cohesive strength and water swelling properties that have been frequently used as carriers for agricultural and horticultural granules. This makes it possible to reduce the amount of high-quality bentonite used. It also provides granules with a cohesive strength that cannot be obtained with conventional dispersants such as sodium lignin sulfonate and sodium acrylate polymers, as well as excellent disintegration and spreadability in water, allowing the active ingredient to exert its efficacy. . The present invention will be further explained below with reference to Examples and Test Examples, but the present invention is not limited thereto. "Parts" in Examples and Test Examples mean "parts by weight." Examples 1 to 8, Comparative Examples 1 to 4 The copolymers shown in Table 1 were used as the dispersant of the present invention and comparative products.

[Table] Reference example 1 10 parts of 2,4,6-trichlorophenyl-4-nitrophenol (generic name: CNP), bentonite
Grind and mix 15 parts and 73 parts of clay, and add the table below.
2 parts of copolymer No. 1 (Examples 1, 8, 7 and Comparative Examples 2, 4) and 17 parts of water were added, kneaded, and
Granulation is carried out using an extrusion granulator with a 0.7 mm screen, and after sieving, 16 to 23 mesh
CNP granules were obtained. Reference Example 2 5 parts of 2-chloro-2',6'-diethyl-N-(butoxymethyl) and acenoanilide (generic name butachlor) were adsorbed and mixed with 5 parts of white carbon [Curbrex #80: manufactured by Shionogi Pharmaceutical Co., Ltd.] Add and mix 30 parts of bentonite and 59 parts of talc,
To this, 1 part of the copolymer shown in Table 2 and 17 parts of water were added, kneaded, and granulated and dried using an extrusion granulator with a screen of 0.7 mm in diameter.
Butachlor granules of 32mesh were obtained. Test Example 1 The physical properties of the CNP granules of Examples 1 to 8 and Comparative Examples 1 to 4 were evaluated by the following test method. The results are shown in Table-3. Γ Disintegration rate test method: Pour the granules through a standard mesh sieve of 500μ
Sieve thoroughly in the sieve until almost no residue remains on the sieve, then use as a sample.
Precisely weigh 100g of sample, diameter 30±2mm, weight 35
Place in a ball mill porcelain pot (inner diameter 100 mm x inner depth 100 mm) containing three porcelain balls weighing ±3 g.
This ball mill porcelain pot was placed on a variable roller ball mill and rotated at 100 revolutions per minute for 10 minutes. Thoroughly measure the contents through a standard 500μ mesh sieve and accurately weigh the weight (Ag) of the sample remaining on the sieve. The disintegration rate (%) was determined using the following formula. Collapse rate (%) = 100-A/100×100 Γ Underwater collapse expansibility test method: Pour 3-degree hard water into a shear tray with a diameter of 10 cm so that the depth of the soil is 1 cm.
Maintain temperature at 18°C. One granule (granule 0.7 mm, length 1.8 mm) was gently added to the center of this shearlay, and after 30 minutes, the area (mm ² ) of the granule disintegrating in water was measured.

[Table] As is clear from Table 3, the granules using the dispersant of the present invention have a lower disintegration rate than conventional ones and have good disintegration and spreadability in water. Test Example 2 A herbicidal effect test was conducted using butachlor granules containing Examples 1, 8, and 7 and Comparative Examples 2 and 4 as dispersants. The results are shown in Table 4. Weeding effect test method: Fill a pot with a 12 cm inner diameter and fill it with paddy soil, and sow it with wild grass seeds.
It was submerged in water to a depth of 3 cm and left in a greenhouse. Granules 0.024g at the time when the sown wildflowers germinate.
(equivalent to 2 Kg/10a) was applied uniformly to the pot.
Thereafter, the plants were grown in a greenhouse for two weeks, and the herbicidal effect of the granules on grasshoppers was observed. Comparing the state of weeds with the state of the untreated area, weeds are rated "0" if there is no or almost no difference, and "5" if they are completely suppressed.
The time period is divided into 6 stages and displayed.

[Table] As is clear from Table 3, the agricultural and horticultural granules using the dispersant of the present invention have better disintegration and spreadability in water than those of the comparative examples, and also have a better herbicidal effect.

Claims (1)

[Scope of Claims] 1 Maleic acid (salt) (a), styrenes (b) and (meth)acrylic acid alkyl ester (however, the number of carbon atoms in the alkyl group is 2 to 20) (c) are essential. A dispersant for agricultural and horticultural granules that disintegrates and expands in water, characterized by containing a copolymer as a constituent unit. 2 The copolymer is (a). (b). (c) Methyl methacrylate
The dispersant according to claim 1, which is a copolymer composed of (d) and, if necessary, another unsaturated monomer (e). 3 The copolymer is (a) and [(b). (c) and (d)] has a molar ratio of 1:0.3 to 3.
Dispersant as described in section. 4 The copolymer is (a). (b). (c). The molar ratio of (d) to 1 mole of (a) is 0.2 to 0.9 for (b), 0.05 to 0.5 for (c), and 1 mole for (d).
The dispersant according to claim 2 or 3, which has a molecular weight of 0.05 to 0.5. 5. The dispersant according to any one of claims 1 to 4, wherein the copolymer has a molecular weight of 1,000 to 200,000.