JPH02250804A - Herbicidal composition - Google Patents

Abstract

PURPOSE: To obtain a herbicidal composition reduced in toxicity to animals, and containing a bipyridylium quanternary cation salt and a compound selected from polyvinyl alcohol sulfuric esters and their salts sand polyvinylsulfonic acids and their salts. CONSTITUTION: This herbicidal composition contains a herbicidally active compound selected from compounds of formula I and formula II [(r) and (r') are each a (substituted) 1-4C alkyl; [X]<m-> is an anion; (m) is 1-4] and a compound selected from compounds of formula III (R is H or SO3 M; M is a metal cation, H ion, etc.; (n) is >=2; at least one R is SO3 M) and compounds of formula IV (R' is H or SO3 ; M is a metal cation, H ion, etc.; (n') is >=2; at least one R' is SO3 M). This composition, which is markedly reduced in toxicity to humans while retaining the herbicidal activity of the compound of formula I or formula II, can be obtained inexpensively.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a herbicidal composition comprising a salt of bipyridylium quaternary cation, and more specifically,
The present invention relates to a herbicidal composition which maintains the herbicidal activity of a herbicide comprising a salt of bipyridylium quaternary cation while significantly reducing its toxicity to animals.

[Prior Art] Bipyridylium quaternary cation salts are widely used worldwide as excellent herbicides. However, since bipyridylium quaternary cation salts have relatively high toxicity to animals such as humans, they are designated as non-pharmaceutical toxic or deleterious substances. Although it does not cause particular harm to the human body if used with sufficient care in accordance with laws and regulations, it cannot be denied that poisoning and death accidents have occurred due to accidental ingestion, misuse, or misuse of the drug concentrate. be.

Therefore, in order to reduce and prevent poisoning accidents caused by bipyridylium quaternary cation salts, emetics are added to the stock solution of the preparation (Japanese Patent Publication No. 5B-35641), and in order to avoid misidentification, it is necessary to identify the product as a pesticide. Blue pigments and odorants are added to facilitate this process. However, these are only measures and proposals for preventing poisoning accidents, and the bipyridylium quaternary cation salt-containing herbicide composition itself is still toxic.

[Problems to be Solved by the Invention] Under these circumstances, there has been a desire for a herbicide that maintains excellent herbicidal effects and has low toxicity to the human body.

An object of the present invention is to provide, at a low cost, a herbicidal composition that maintains the long-desired excellent herbicidal effect and further reduces toxicity to the human body.

[:l1 Means for Solving the Problem] As a result of research, the present inventor has determined that the toxicity of bipyridylium quaternary cation salts having herbicidal effects is It has been found that this can be significantly alleviated by adding at least IPli selected from polyvinylsulfonic acid and its salts. The present invention was completed based on this knowledge.

The present invention provides a herbicide comprising a bipyridylium quaternary cation salt having a herbicidal action and one or more compounds selected from polyvinyl sulfuric acid and its salts, and polyvinyl sulfonic acid and its salts. Regarding the composition.

As polyvinyl sulfate and its salts and polyvinyl sulfonic acid and its salts, in the formula c, R represents hydrogen or 503M, and M represents a metal cation, hydrogen ion or other cation. However, at least one inner number of R is 503M, and n represents a number of 2 or more. ] and [wherein R' represents hydrogen or 503M, and M represents a metal cation, hydrogen ion or other cation. However, at least one of the inner numbers of R/ is 503M, and n
' represents a number of 2 or more. ] One or more compounds selected from the following are suitable.

In the polyvinyl sulfate and its salt formula (I), the preferred proportion of 503M for R is 90% or more, and n
The preferred range of is 10 to 3000.

Further, in polyvinyl sulfonic acid and its salt formula (II), the preferred proportion of 803M for R' is 90%.
The preferred range of n' is 5 to 1000.

In addition, derivatives of formulas (I) and (II), such as compounds containing both a sulfuric acid ester (or salt thereof) group and a sulfonic acid (or salt thereof) group in the polyvinyl molecule, can also be used.

By adding and mixing polyvinyl sulfuric acid and its salts and polyvinyl sulfonic acid and its salts with the salt of bipyridylium quaternary cation in this way, even if it is accidentally swallowed, no noticeable symptoms of poisoning will be exhibited. Therefore, the present invention provides an extremely safe herbicidal composition that maintains herbicidal activity with almost no reduction and has significantly reduced toxicity.

In the present invention, the most preferred salts of polyvinyl sulfuric acid and its salts and polyvinyl sulfonic acid and its salts that are added to alleviate toxicity include monovalent metals such as sodium and potassium, as well as calcium, magnesium,
Metal salts such as aluminum, ammonium salts, etc. can be considered.

Polyvinyl sulfate potassium salt is a compound represented by formula (I), where R is H or S03.

When preparing a liquid preparation, n in the formula is preferably 3000 or less. If it exceeds 3000, the solution becomes quite viscous.

Particularly preferred polyvinyl sulfate potassium salt has n of 100
~2000, with a sulfur content of 15 to 19.8%. In the case of a granular solid preparation, n may be 3000 or more without any particular problem. In addition, polyvinylsulfonic acid sodium salt is a compound represented by formula (n), where n'
is preferably 2000 or less.

If it exceeds 2000, the solution becomes quite viscous. Particularly preferred polyvinylsulfonic acid sodium salts have n′ of 15 to
2001 with a sulfur content of 120 to 24.7%.

The herbicidal bipyridylium quaternary cation salt used in the composition of the present invention is a compound represented by the following formula.

In the above formula, r and r' may be the same or different, and each is an alkyl group having 1 to 4 carbon atoms, or hydroxy, halogen, carboxyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, carbamoyl, and N-substituted represents an alkyl group having 1 to 4 carbon atoms substituted with a group selected from rubamoyl, (X)"- represents an anion, and m represents an integer of 1 to 4.

Bipyridylium quaternary cation salts having particularly preferable herbicidal activity are shown below.

■, 1'-dimethyl-4.4'-bipyridylium di(
Methyl sulfate) [Balaquat dimethosulfate].

l, 1'-ethylene-2,2'-bipyridylium dibromide [diquat dibromide].

1.1'-dimethyl-4,4'-bipyridylium dichloride [paraquat dichloride].

1-(2-hydroxyethyl)-1'-methyl-4,
4' Bipyridylium dichloride.

1.1'-di-carbamoylmethyl-4,4'-bipyridylium dichloride.

1.1'-Bis-N,N-dimethylcarbamoylmethyl-4,4'-bipyridylium dichloride.

1.1'-dimethyl-4,4'-bipyridylium sulfate [balaquat sulfate].

1.1'-bis(3,5-dimethylmorpholinecarbonylmethyl)-4,4'-bipyridylium dichloride [Morhamcote dichloride].

1.1'-Bis-N,N-diethylcarbamoylmethyl-4,4'-bipyridylium dichloride.

1.1'diacetonitrile-4,4'-bipyridylium dichloride.

l,1'-jethoxycarbonylmethyl-4,4'-bipyridylium dibromide.

The names in brackets [ ] in the above compounds are their common names. For example, "paraquat ion" is 1,1'-dimethyl-
Common name for the 4,4'-bipyridylium cation.

A particularly preferred bipyridylium cation for use in the compositions of the invention is paraquat.

A particularly preferred anion (X)"- is the chloride ion for reasons of convenience and economy, but any anion that conveniently gives a water-soluble salt can be used if desired. Only the bipyridylium cation has herbicidal action. Because of this, the concentration of herbicidal bipyridylium cationic salt compositions is often indicated solely by the cation.

The degree of reduction in toxicity of the bipyridylium quaternary cation salt in the herbicidal composition of the present invention is determined by one or more compounds selected from polyvinyl sulfuric acid and its salts, polyvinyl sulfonic acid and its salts, which are added. depends on. If the addition rate of one or more of the above compounds to the bipyridylium quaternary cation salt is increased, the toxicity will be greatly reduced, but on the other hand, the herbicidal effect of the bipyridylium quaternary cation salt may be affected. becomes. Therefore, the blending ratio of the same components can be determined while taking into consideration the herbicidal effect and the degree of toxicity reduction. Generally, it is preferable to adjust the ratio to such a level that the toxicity of the bipyridylium quaternary cation salt exceeds the lethal dose and the herbicidal effect can be maintained. However, since the lethal dose in humans cannot be directly measured, it can only be estimated through animal tests.

A preferred composition ratio is 1 to 5 parts by weight of one or more compounds selected from polyvinyl sulfuric acid and its salts, and polyvinyl sulfonic acid and its salts, per 1 part by weight of bipyridylium quaternary cation salt. This is the case with percentages.

Particularly preferably, 2 to 4 parts by weight of one or more compounds selected from polyvinyl sulfuric acid and its salts and polyvinyl sulfonic acid and its salts is used per 1 part by weight of bipyridylium quaternary cation salt. .

A carrier or diluent may be included in the composition of the invention, and the composition may be solid, e.g. particulate or liquid.
For example, it can be an aqueous solution. The amount of herbicidal bipyridylium quaternary cation present in the aqueous solution is 50-400 g/l
is preferred.

Preferably, the composition of the present invention further contains a surfactant.

Surfactants that can be used are cationic, nonionic or anionic; anionic surfactants are
The bipyridylium quaternary cation salt in the composition and the cationic surfactant are one or more compounds selected from polyvinyl sulfate and its salts and polyvinyl sulfonic acid and its salts in the composition. In general, nonionic surfactants are preferred, since each may have undesirable effects. Examples of nonionic surfactants that can be used in the compositions of the invention are addition products of ethylene oxide and alkylphenols such as octylphenol, nonylphenol and octylcresol. Examples of other nonionic surfactants are partial esters derived from long chain fatty acids and hexit anhydride, such as sorbitan monolaurate, addition products of such partial esters with ethylene oxide, and lecithins.

In the composition of the present invention, all of the auxiliaries, diluents, etc. that are conventionally added to this type of herbicide can be present as necessary. For example, dyes, pigments, etc. for coloring by profession can be added as necessary. Examples of such compounds are “MonastraJ BIL!
G BNV Pa5to' and 'Li5sai1no
Turquoiso VN 150”.

Compositions of the invention may further contain odorants. Examples of such odorants are alkylpyridines, n-valeric acid and tetrahydrothiophene as described in GB 1408881.

If desired, one or more compounds selected from polyvinyl sulfuric acid and its salts of formula (I) and polyvinyl sulfonic acid and its salts of formula (■) are quaternary cationic salts having herbicidal activity. can be included in the species modification composition. In particular, one or more compounds selected from polyvinyl sulfuric acid and its salts (I) and polyvinyl sulfonic acid and its salts (II) are disclosed in British Patent No. 139550.
It can be included in the composition of the herbicidal bipyridylium quaternary cation salt described in No. 2 Akio. Such compositions are prepared from aqueous solutions of herbicidal bipyridylium quaternary cation salts containing gelling agents, such as finely divided silica, or a combination of xanthan gum and sodium metaborate, sold under the trade name "KO3Zan". Become. Xanthan gum is a complex polysaccharide.

The composition of the present invention was tested for herbicidal activity and acute toxicity. The results show that the herbicidal composition of the present invention is able to maintain herbicidal action while drastically reducing acute toxicity.

Test Example 1 Herbicidal effect Balaquat dichloride formulation (manufactured by IC1 [Gramoxone SJ (preparation containing 24% by weight of baraquat dichloride), trade name]) containing 600p of baraquat dichloride
Potassium polyvinyl sulfate salt (n - about 1500. S content 19.0%) and sodium polyvinyl sulfonate (n / - about 1
50. S content 24.6%) at three concentrations (2aoopp
■, 12009p■, 600ppm), prepared three types of aqueous solutions, and prepared small polystyrene bowls (
Wildflowers (plant height 4cl) being cultivated in 20x15x 5cm)
l), wheat (plant height 15cm), and cabbage (plant height: (, 5ell)).
It was evenly distributed at a ratio of . Seven days after treatment, herbicidal activity was evaluated based on mortality rate.

tut (p disorder) □ Mortality rate Nobie Wheat Cabbage tr45 5 5 1:2 5 5 5 1:1 5 5 5 1:4 5 5 5 1:2 5 5 5 1:l 5 5 5 PQ Bo.

PQ+PVK 800+2400 PQ+PVK 60041200 PQ+PVK　eoo+eo.

PQ+PSN 80042400 PQ+PSN 60041200 PQ+PSN　eoo+eo.

In the table, PQ represents baraquat dichloride, PVK represents polyvinyl sulfate potassium salt, and PSN represents polyvinyl sulfonic acid sodium salt.

The herbicidal activity determination criteria for mortality rate are as follows.

(Standard > 5: 100% blight 4, 80% blight 3: 60% blight 2, 40% blight 1: 20% blight 0: No effect Test example 2 Acute toxicity baraquat dichloride and polyvinyl sulfate potassium salt (
n - about 1500. S content fl 19.0%) and polyvinyl sulfonic acid sodium salt (n'-approximately 150° S content 2
4.8%) in various ratios, dissolved in distilled water, and orally administered to 4-week-old ddY mice (1, weight 18-20 g). Food was removed 12 hours before administration to cause a fast, and the animals were fed again 2 to 3 hours after administration. The LD5o value was determined by the probit method based on the survival rate on the third day after administration.

Table 1 shows the LDs for the blend of baraquat dichloride and polyvinyl sulfate potassium salt, and Table 2 shows the LDs for the blend of baraquat dichloride and polyvinyl sulfonic acid sodium salt.

Show value.

Table 1 132 (108-152) 272 (226-321) 355 (270-451) 649 (551-730) 849 (477-971) 1003 (836-1134) Table PQ: PSN 1: 0 132 (108-152) )1
: 0.5 254 (173-323) 1 :
1 398 (333-491) 1 : 2
604 (413-694) 1 : 3
810 (541-911) 1: 4
898 (592-1044) Note: In the table, PQ represents baraquat dichloride, PVK represents polyvinyl sulfate potassium salt, and PSN represents polyvinyl sulfonic acid sodium salt.

LD5o is shown as the amount of baraquat dichloride.

The numbers in parentheses indicate the upper and lower limits of the 95% confidence limit, indicating that L D 50 is within this range.

This result explains that the herbicidal composition according to the present invention has significantly lower toxicity than the known baraquat dichloride formulation, and the possibility of serious problems occurring due to its ingestion is significantly reduced. be.

Next, formulation examples of the composition of the present invention will be shown.

Formulation Example 1 10g of baraquat dichloride was dissolved in 20g of water. On the other hand, 20 g of polyvinyl sulfate potassium salt was dissolved in 30 g of water, and these solutions were mixed and stirred. Next, 5 g of polyoxyethylene nonylphenyl ether was added and diluted with water while stirring to a total amount of 100 g.
A composition of the invention containing 0% was obtained. This composition can be further diluted 150 to 200 times for practical use.

Formulation Examples 2 to 8 Balaquat dichloride (PQ) was dissolved in twice the weight of water, diquat dibromide (DQ) was dissolved in the same weight of water, and polyvinyl sulfate and polyvinyl sulfonate were dissolved.
Each was dissolved in the same weight of water to form a solution.

These were sequentially mixed and dissolved according to the table below, then a predetermined amount of surfactant was added, and finally diluted with water to obtain herbicide compositions of the present invention each having a predetermined concentration.

These compositions can be used after being diluted 100 to 500 times with water.

DQ: Diquat dibromide PVK: Polyvinyl sulfate potassium salt (SL9.
0%) PSN: Polyvinylsulfonic acid sodium salt (8
24.6%) POENP: Polyoxyethylene nonylphenyl ether POENO: Polyoxyethylene octylphenyl ether Note) The abbreviations represent the following compounds.

PQ: Balaquat dichloride [Effect of the invention] A bipyridylium quaternary cation salt that exhibits an extremely excellent herbicidal effect but is highly toxic to animals such as humans.
A weed killer that maintains excellent herbicidal effects and reduces toxicity to the human body by containing one or more compounds selected from polyvinyl sulfate and its salts and polyvinyl sulfonic acid and its salts. It has become possible to provide drug compositions at low cost.

Claims (4)

[Claims] (1) Contains a salt of bipyridylium quaternary cation having herbicidal activity and one or more compounds selected from polyvinyl alcohol sulfate and its ester salt, and polyvinyl sulfonic acid and its salt. A herbicide composition. (2) Salts of bipyridylium quaternary cations have the formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ and formulas ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [In the formula, r and r' may be the same or different. each having 1 to 4 carbon atoms substituted with an alkyl group having 1 to 4 carbon atoms or a group selected from hydroxy, halogen, carboxyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, carbamoyl, and N-substituted carbamoyl; Represents 4 alkyl groups, [X]^m^-
represents an anion, and m represents an integer of 1 to 4. The herbicidal composition according to claim 1, which is selected from the compounds represented by the following. (3) Polyvinyl alcohol sulfate ester or its ester salt has the formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (I) [In the formula, R represents hydrogen or SO_3M, and M is a metal cation, hydrogen ion, or other cation represents. However, at least one of R is SO_3M, and n is 2
represents a number greater than or equal to The herbicidal composition according to claim 1, which is a compound represented by the following formula. (4) Polyvinylsulfonic acid or its salt has the formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (II) [In the formula, R' represents hydrogen or SO_3M, and M is a metal cation, hydrogen ion, or other cation represents. However, at least one of R' is SO_3M, and n' represents a number of 2 or more. The herbicidal composition according to claim 1, which is a compound represented by the following formula.