JPH04338308A - Herbicide for upland field - Google Patents

Abstract

PURPOSE:To obtain a herbicide for upland fields in a state of aqueous micro emulsion, suitable for selectively controlling weeds in upland fields growing especially wheat, etc., having physical and chemical stability and not showing lack of uniformity even after low-temperature and high-temperature preservation for a considerably long period of time. CONSTITUTION:A herbicide for upland fields, comprising an aqueous concentrated emulsion containing (A) a salt of a compound shown by the formula (R is lower alkyl) and 3,6-dichloro-2-methoxybenzoic acid, especially K salt, Na salt and diethanolamine salt as an active ingredient of herbicide, (B) a surfactant composed of two or more components selected from ethoxylated styryl phenyl ether, an ethylene oxide-propylene oxide-ethylene oxide-block copolymer and ethoxylated castor oil as an essential component of dodecylbenzenesulfonate, (C) one or more organic solvents selected from an aromatic compound and ketones and (D) water in a ratio of 2-25wt.% component A, 1-30wt.% component B, 10-30wt.% component C and 10-70wt.% component D as a base.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a herbicide for upland use in the form of an aqueous microemulsion. For more details, see 2.
The present invention relates to an aqueous microemulsion herbicide for upland use containing a nitro-5-(substituted phenoxy)benzohydroxymic acid derivative as one of the active ingredients.

0002

[Prior Art] The following general formula (I):

0003

[Chemical 2]

The 2-nitro-5-(substituted phenoxy)benzohydroxymic acid derivative represented by the formula (R represents a lower alkyl group) can be used in fields where wheat such as wheat, barley, and oats grow, or It is known that it is useful as a selective herbicide in agricultural land where rice, corn, etc. grow (see JP-A-63-215605). On the other hand, the herbicide 3,6-dichloro-2-methoxybenzoic acid salt (hereinafter referred to as Dicamba salt) is a herbicide that has long been used worldwide as a broad-leaved weed control agent.

[0005]

[Problems to be Solved by the Invention] An object of the present invention is to contain an aqueous solution of a benzohydroxyme derivative and Dicamba salt in a single formulation, which is physically and chemically stable while preventing phase separation and aggregation. To provide a herbicide for upland fields that provides a uniform formulation, requires a small amount of applied chemicals, and has excellent crop selectivity.

[0006]

[Means for Solving the Problems] According to the present invention, by using a specific surfactant together with the above-mentioned herbicide active substance, a transparent microemulsion is obtained, which can be stored for a considerable period of time at low and high temperatures. It was later discovered that it is physically and chemically stable and shows no heterogeneity, leading to the completion of the present invention.

[0007] Therefore, the present invention (a) As a herbicide active substance, the following general formula (I):

0
008]

[C3]

A 2-nitro-5-(substituted phenoxy)benzohydroxymic acid derivative represented by (wherein R represents a lower alkyl group) and a salt of 3,6-dichloro-2-methoxybenzoic acid, ( b) A surfactant comprising dodecylbenzenesulfonate as an essential component and at least two components selected from the group consisting of ethoxylated styryl phenyl ether, ethylene oxide-propylene oxide-ethylene oxide block copolymer, and ethoxylated castor oil. (c) one or more organic solvents selected from the group consisting of aromatic compounds and ketones;
and (d) water.

One of the ingredients used as an active substance in the herbicide of the present invention is a specific compound which is a 2-nitro-5-(substituted phenoxy)benzohydroxymic acid derivative represented by the above general formula (I). An example is as follows. Compound no. 1: Methyl O-methoxycarbonylmethyl-5-(2,4-dichloro-3-methylphenoxy)
-2-nitrobenzohydroxymate (syn) (melting point 106.5-107.0°C) Compound No. 2: Methyl O-methoxycarbonylmethyl-5-(2,4-dichloro-3-methylphenoxy)-2-nitrobenzohydroxymate (anti) (melting point 90.5-93°C)

Compound No. 3: Ethyl O-methoxycarbonylmethyl-5-(2,4-dichloro-3-methylphenoxy)-2-nitrobenzohydroxymate compound No. 4: n-propyl O-methoxycarbonylmethyl-5-(2,4-dichloro-3-methylphenoxy)-2-nitrobenzohydroxymate compound No. 5
:iso-propyl O-methoxycarbonylmethyl-
5-(2,4-dichloro-3-methylphenoxy)-2
-Nitrobenzohydroxymate compound No. 6:n-
Butyl O-methoxycarbonylmethyl-5-(2,4
-dichloro-3-methylphenoxy)-2-nitrobenzohydroxymate

Another active substance used in the herbicide of the present invention is a salt of 3,6-dichloro-2-methoxybenzoic acid. The compound and its herbicidal activity have been known for a long time, for example in U.S. Pat. No. 3,013.
, 054.

[0013] Surfactants used in the present invention include:
Dodecylbenzene sulfonate, e.g. sodium salt,
Calcium salt; ethoxylated styryl phenyl ether (e.g. 10-40 ethylene oxide (EO)
units); and ethoxylated castor oil (
for example, those containing 20 to 80 ethylene oxide units), or ethylene oxide-propylene oxide-ethylene oxide block copolymers (molecular weight 2
000 to 8,000, having 80 to 200 ethylene oxide groups and 60 to 140 propylene oxide groups). Among the above compounds, dodecylbenzenesulfonate is an essential component, and at least two other components are required as surfactants.

Aromatic compounds used as organic solvents include, for example, toluene and xylene; aromatic fractions with high boiling points, such as 1-methylnaphthalene, 2-methylnaphthalene, 2,6-dimethylnaphthalene, trimethylbenzene,
Examples include diethylbenzene and tetramethylbenzene. In addition, SOL, which is a mixture of high-boiling aromatic fractions,
VESSO 150 (boiling range 191°C to 212°C) and SOLVESSO 200 (boiling range 227°C to 2
86°C) [manufactured by EXXON Chemical Co., Ltd.] can also be used. Cyclohexanone is particularly suitable as the ketone.

The ratio of aqueous to organic phase in the formulation generally varies between 5:1 and 1:1. Usually the active substance concentration in the aqueous phase is between 10 and 60% by weight and in the organic phase between 1 and 80% by weight. The upper limit is determined in each case by the solubility of the active substance used. Typically, the formulation comprises (a) 2-25% by weight of active substance, preferably 5-20% by weight, (b) 1-30% by weight of surfactant, preferably 5-20% by weight.
% by weight, (c) organic solvent 10-30% by weight, preferably 15-2
5% by weight and (d) 10-70% by weight, preferably 15-55% by weight of water.

The herbicide of the present invention is prepared, for example, as follows. The above components are mixed in the required amounts and brought to a region of high turbulence at 10° C. to 60° C., preferably around room temperature, until a stable, transparent microemulsion is formed. Specifically, an aqueous phase is first prepared by adding an aqueous Dicamba salt solution and optionally additional water. Next, the water-insoluble 2-nitro-5- to be emulsified
The (substituted phenoxy)benzohydroxymic acid derivative is dissolved in an organic solvent and a surfactant is added. The organic phase thus formed is gradually added to the aqueous phase with vigorous stirring. After some time a transparent microemulsion is formed.

[0017] Specific examples of weeds to be controlled by the herbicide of the present invention include, for example, the weeds that are to be controlled by the herbicide of the present invention;
Japanese poppy, Japanese poppy, Ezo-suzushiro, forget-me-not,
Examples of these weeds include Michiyanagi, Breakstone, Ichibi, Ona fir, Maruba morning glory, and Aoyubia, and these weeds can be treated with a dosage of 5g to 2
Particularly effective control is possible within the range of 0.00 g.

The herbicide of the present invention is particularly suitable for selective weeding in fields where wheat species such as wheat, barley, and oats usually grow, but is also suitable for selective weeding in fields where wheat species such as wheat, barley, and oats grow. It can also be suitably used for selective weeding in the ground. Furthermore, the lawn
Good results can be obtained when applied to fields such as orchards, forest nurseries, and non-agricultural lands.

[0019]

EXAMPLES The following examples illustrate the invention in further detail. Example 1 Compound No. 1 (MY-09) 4% by weight as SOLV
ESSO200 10% by weight and cyclohexanone 2
6.5% by weight of calcium dodecylbenzenesulfonate, 6.5% by weight of ethoxylated styryl phenyl ether (12 EO units), 11.5% by weight of ethoxylated castor oil (60 EO units). % and stir to obtain a homogeneous organic phase. This organic phase is gradually added under vigorous stirring to an aqueous phase containing 8% by weight of Dicamba dimethylamine salt and 2% by weight of ethylene oxide-propylene oxide-ethylene oxide block copolymer dissolved in 39.5% by weight of water. After some time, a clear microemulsion was formed, which was chemically stable.

Comparative Example 1 Compound No. 1 4% by weight SOLVESSO 20
0 10% by weight and dissolved in 20% by weight of cyclohexanone, 6% by weight of calcium dodecylbenzenesulfonate, 10% by weight of polyoxyethylene fatty acid polyglycol ester (40 EO units), ethoxylated castor oil (40 EO units). Mix and stir 5% by weight to obtain a homogeneous organic phase. The organic phase is gradually added under vigorous stirring to the aqueous phase in which 8% by weight of Dicamba dimethylamine salt is dissolved in 22% by weight of water. After a while, a transparent microemulsion was formed, which phase separated after being left at room temperature for 2 hours.

Test Example 1 A square pot measuring 30 x 30 x 9 cm was filled with field soil.
A certain amount of crop seeds and weed seeds shown in Table 1 were sown, covered with soil to a thickness of 1 cm, and cultivated for 40 days at appropriate temperature and humidity. For chemical treatment, a preparation prepared by mixing Example 1, Example 2 and each herbicide immediately before treatment was used, and the preparation was diluted with water to the amount of each active ingredient shown in Table 1. 0.5 ml of the solution was evenly sprayed onto the stems and leaves of the plant. On the 30th day after chemical treatment, the herbicidal effect on each weed and the degree of chemical damage to each crop were evaluated on a 100-point scale (0: no effect to 100: complete death).
) and the results are shown in Table 1.

[0022]

[Table 1]

Claims (3)

[Claims] Claim 1: (a) As a herbicide active substance, 2-nitro-5-(substituted phenoxy) represented by the following general formula (I): [Formula 1] (wherein R represents a lower alkyl group) A benzohydroxymic acid derivative, a salt of 3,6-dichloro-2-methoxybenzoic acid, (b) dodecylbenzenesulfonate as essential components, ethoxylated styryl phenyl ether, ethylene oxide-propylene oxide-ethylene oxide block copolymer a surfactant consisting of at least two components selected from the group consisting of coalesced and ethoxylated castor oil; (c) one or more organic solvents selected from the group consisting of aromatic compounds and ketones; d) Field herbicides based on aqueous concentrated microemulsions, characterized in that they contain water. 2. The herbicide according to claim 1, wherein the salt of 3,6-dichloro-2-methoxybenzoic acid is one or more salts selected from the group consisting of potassium, sodium, and diethanolamine. Claim 3: (a) 2 to 25% by weight of active substance, (b
) surfactant 1-30% by weight, (c) organic solvent 10-30% by weight, and (d) water 10-30% by weight.
The herbicide according to claim 1, containing 70% by weight.