Drug – bio-affecting and body treating compositions – Preparations characterized by special physical form – Biocides; animal or insect repellents or attractants
Reexamination Certificate
1999-07-19
2001-10-23
Dudash, Diana (Department: 1619)
Drug, bio-affecting and body treating compositions
Preparations characterized by special physical form
Biocides; animal or insect repellents or attractants
C514S365000
Reexamination Certificate
active
06306414
ABSTRACT:
TECHNICAL FIELD
The present invention relates to an agricultural aqueous suspension characterized by excellent pesticidal activity, low viscosity, and excellent suspension stability.
BACKGROUND ART
Heretofore, as dosage forms for agricultural pesticides, dusts and granules have been primarily used. Those dosage forms are prepared by formulating a small amount of a pesticidally active substance with a large amount of a carrier such as clay, bentonite, calcium carbonate, etc. and, therefore, such formulations must be applied in quantities as large as 2 to 6 kilograms/10 ares in order to insure a uniform distribution of the active substance. This imposes a great burden on the farmers and, moreover, there are many disadvantages in transportation and storage. For this reason, so-called concentrates, which are supplied in small packages to provide for a greater ease of handling, are being developed.
Those concentrates are rich in the active substances and can be applied after dispersion in a suitable diluent, such as water, in the field. Examples include emulsifiable concentrates and wettable powders. However, emulsifiable concentrates require large quantities of an organic solvent for dilution, while it is unavoidable with wettable powders that preparation of sprays in the field involves contaminations with flying solid particles. For those reasons, the recent trend is toward refraining from using those formulations. Wettable granules, which are granular versions of wettable powders have almost overcome the drawbacks of wettable powders but because the size of particles dispersed in water is as large as about 10 and odd &mgr;m, application of a dispersion of high concentration causes clogging of the spray nozzle, among other disadvantages.
The compound of the formula (I):
or a salt thereof, is an agricultural pesticide having potent pest-controlling activity.
The demand exists today for development of a stable aqueous suspension of the compound (I) or a salt thereof which should have a low viscosity enough to permit smooth delivery from a container as well as satisfactory dispersibility in diluent water and long-term fluidity free from caking due to precipitation of the suspended particles.
DISCLOSURE OF INVENTION
The inventors of the present invention have made much research to overcome the above-mentioned disadvantages of the prior art and found that an aqueous suspension comprising (i) the compound (I) or a salt thereof, (ii) a condensate of formaldehyde with aromatic sulfonic acid or a salt thereof or a polyoxyalkylene allyl phenyl ether sulfate, and (iii) an absorptive water-soluble polymer in combination may have a low viscosity of not more than 700 mPa·s with excellent dispersibility in diluent water and, in addition, have a long-term stability. The inventors have made further research and have completed the present invention.
Namely, the present invention relates to:
(1) an aqueous suspension which comprises (i) a compound of the formula (I):
or a salt thereof, (ii) a condensate of formaldehyde with an aromatic sulfonic acid or a salt thereof or a polyoxyalkylene allyl phenyl ether sulfate, and (iii) an absorptive water-soluble polymer,
(2) the aqueous suspension as described in (1) above, wherein the aqueous suspension contains about 1 to 10 weight % of the condensate of formaldehyde with aromatic sulfonic acid or a salt thereof or the polyoxyalkylene allyl phenyl ether sulfate in the total aqueous suspension,
(3) the aqueous suspension as described in (1) above, wherein the absorptive water-soluble polymer is one or more (preferably one to three) polymers selected from the group consisting of polyvinylpyrrolidone, poly(alkylated vinylpyrrolidone), vinylpyrrolidone-styrene block copolymer and methyl vinyl ether-maleic anhydride copolymer,
(4) the aqueous suspension as described in (1) above, which further comprises an unabsorptive water-soluble polymer,
(5) the aqueous suspension as described in (4) above, wherein the unabsorptive water-soluble polymer is one or more (preferably one to three) polymers selected from the group consisting of a polymer in the polyol series, a polysaccharides and polyethylene glycol,
(6) the aqueous suspension as described in (4) above, wherein the unabsorptive water-soluble polymer is one or more (preferably one to three) polymers selected from the group consisting of xanthan gum, starch and polyethylene glycol,
(7) the aqueous suspension as described in (1) above, which further comprises an auxiliary suspending agent,
(8) the aqueous suspension as described in (7) above, wherein the auxiliary suspending agent is one or more (preferably one to three) substances selected from the group consisting of montmorillonite, colloidal silicon oxide, silicon oxide-aluminum oxide colloidal mixture and sepiolite,
(9) a method for producing the aqueous suspension as described in (1) above, which comprises suspending (i) in the compound of the formula (I):
or a salt thereof, (ii) the condensate of formaldehyde with an aromatic sulfonic acid or a salt thereof or the polyoxyalkylene allyl phenyl ether sulfate, and (iii) the absorptive water-soluble polymer in water, and
(10) a method for controlling a pest which comprises scattering the aqueous suspension as described in (1) above into a field.
BEST MODE FOR CARRYING OUT THE INVENTION
The compound (I) which is guanidine derivative for use in the aqueous suspension of the present invention occurs as trans (E) and cis (Z) isomers in respect of the geometrical orientation of NO
2
. Preferred, however, is (E)-1-(2-chlorothiazol-5-ylmethyl)-3-methyl-2-nitroguanidine (hereinafter referred to briefly as compound (Ia)).
The salt of compound (I) includes agrochemically acceptable salts with inorganic acids such as hydrochloric acid, hydrobromic acid, hydroiodic acid, phosphoric acid, sulfuric acid, perchloric acid, etc. and salts with organic acids such as formic acid, acetic acid, tartaric acid, malic acid, citric acid, oxalic acid, succinic acid, benzoic acid, picric acid, p-toluenesulfonic acid, etc.
The production method for the compound (I) or a -salt thereof is described in, inter alia, JP-A 157308/1991.
The proportion of compound (I) or a salt thereof in the aqueous suspension of the present invention is generally about 5-60 weight %, preferably about 5-50 weight %, and more preferably about 10-50 weight %, further more preferably 15-45 weight %.
The condensate of formaldehyde with aromatic sulfonic acid or a salt thereof which can be used in preparing the aqueous suspension of the present invention includes a condensate of formaldehyde with a sulfonic acid such as a phenylsulfonic acid, an aryl-substituted phenylsulfonic acid, a phenolsulfonic acid, an aryl-substituted phenolsulfonic acid, p-toluenesulfonic acid, a naphthalene sulfonic acid, an alkyl-substituted naphthalene sulfonic acid, an aralkyl-substituted naphthalene sulfonic acid, an anthracene sulfonic acid, or an alkyl-substituted anthracene sulfonic acid.
The aryl group of the aryl-substituted phenylsulfonic acid or aryl-substituted phenolsulfonic acid as mentioned above includes C
6-14
aryl groups such as phenyl and naphthyl. The number of the substituents is 1 to 3.
The alkyl group of the alkyl-substituted naphthalene sulfonic acid as mentioned above includes C
1-6
alkyl groups such as methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, sec-butyl and tert-butyl. The number of the substituents is 1 to 7.
The aralkyl group of the aralkyl-substituted naphthalene sulfonic acid as mentioned above includes phenyl-C
1-4
alkyl groups such as benzyl, phenethyl and phenylpropyl; benzhydryl; and trityl. The number of the substituents is 1 to 3.
The alkyl group of the alkyl-substituted anthracene sulfonic acid as mentioned above includes a C
1-6
alkyl group such as methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, sec-butyl and tert-butyl. The number of the substituents is 1 to 9.
The condensed degree between an aromatic sulfonic acid and formaldehyde is 1.2 to 30, preferably 1.2 to 10.
Among them as mentioned above, a naphthalene sulfonate-
Berman Alysia
Dudash Diana
Takeda Chemical Industries Ltd.
Wenderoth , Lind & Ponack, L.L.P.
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