Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
~35~V~
This invention relates to a novel aqueous insecti-
cidal concentrate composition. The term "insecticidal
concentrate composition" used herein is intended to mean a
solution, such as an emulsifiable concentrate, which
contains insec-ticidal compound preferably in a concentration
as high as 2% or more and is practically-applied after
dilution with water to a concentration of below 1%.
An aqueous pesticidal concentrate composition
containing a triazine derivative, a pyridine derivative, a
chlorinated hydrocarbon or others as a pesticidal compound
is disclosed in British Patent No. l,4~6,771. However, ~ .
the British Patent does not disclose an aqueous insecti-
cidal concentrate composition containing an insecticidal
organo-phosphorus compound as an active compound~ An
insecticidal organo-phosphorus compound in such known
aqueous pesticidal concentrate composition in which the
.. :
. active compound is dispersed in water in the form of a
: finely divided solid is very unstable and decomposes with
the lapse of time.
Accordingly, an aqueous insecticidal concentrate
composition containing an insecticidal organo-phosphorus
compound is unknown. ~ .
I~nown concentxate compositions containing an
insecticidal organo-phosphorus compound are generally ~:
~ composed of an insecticidal organo-phosphorus compound, an
. organic solvent, a surface active agent and a stabilizer.
Water is scarcely contained in the compositions (e.g., the
` water content is generally below 1%). This is because
organo-phosphorus compounds which serve as insecticide are
usually poor in stability when water is present. Accordingly,
it has been heretofore considered that the presence of
~1~
. A
~iL05~4~
water in the phosphorus compound-containing concentrate
composition which is essentially required -to have relatively
long shelf liEe must be avoicled.
A]most all of the organic solvents employed in
the known concentrate compositions Eor agriculture or
epidemic prevention, such as emulsiEiable concentrates have
more or less toxity against animals and plants and take part
in air or water pollution leading to many evils when used
as insecticides. Further, the organic solvents employed in
conventional insecticidal concentrate compositions are
ordinarily combustible and have a danger of taking fire, so
that the insecticidal concentrate compositions using such
combustible organic solvents and containing no water must
be handled or stored with the utmost care. ~ccordingly,
use of watex instead of organic solvents is very convenient
from every point of view. In addition, organic solvents
which have been used in insecticides are important as starting
materials for the synthesis of useful compounds or energy
-~ sources. In the sense, the replacement of organic solvents
by water is favourable from a social point of view.
We have found that the use of a surface active
agent in an amount sufficient to render an insecticidal organo~
phosphorus compound soluble in water assuresl unexpectedly,
formation of a stable concentrate composition, so that water ;~ `
may be used instead of organic solvent, and the prior art
problems associated with the use of organic solvents are
avoided.
In accordance with the present invention, there is
provided an aqueous insecticidal concentrate composition
comprising: (a) an insecticidal organo-phosphorus compound,
(b) water, and ~c) a surface active agent in an amount
: .
- 3 -
~OS4~
sufficient to render the organo-phosphorus compound soluble
in -the water, the pEI of the composition ranging from 3.0 to :
8.5. The composition is obtainable as a clear solution
ra-ther than a dispersion because the or~ano-phosphorus
compound is entirely dlssolved in the aqueous medium.
There are usable in the present invention almost
all insectlcidal organo-phosphorus compounds other than a
very few of insecticidal organo-phosphorus compounds of a
type which is very rapidly decomposed upon contact with
water and is thus especially unstable in water. Preferred
phosphorus compounds
:'i
. ', ' .
.`. ' .
'
.
1054049
which are sparingly soluble in water, e.g., a solubility in
water of below about 2 %, are expressed by the following
general formula
Xl '
Rl ~11 X R (I)
(in which Rl represents a lower alkyl preferably having 1 to 3
carbon atoms, R2 represents a lower alkoxy preferably having
1 to 3 carbon atoms or phenyl, R3 represents a phenyl group
having one to three substituents selected from the group
consisting of CH3, NO2, CN, Cl and -S-CH3, 2-isopropyl 4-methyl-
6-pyrimidlnyl group, 3,5,6-irichloro-2-pyridyl group, 1,2-
diethoxycarbonyl group, or l-ethoxycarbonyl-l-phenylmethyl
. group, and Xl and X2 are the same or different and are an oxygen
a~om or a sulfur atom).
Most preferable compounds are expressed by the following
general formula
R O l~ (II)
(in which R4 a Cd3- or C2}l5-, and R5 represents ~ -3-C33,
2 ~ Cl or ~ J~ / 3
Examples of the compounds expressed by the general formulae (I)
`20 and (II) include 0,0-dimethyl-0-(3-methyl-4-methylthiophenyl)
- thiophosphate (hereinafter referred to simply as fenthion),
` - 5 -
.. .
, . s~r ~
' ' ' . ' , ~ ' ' ~ .. ,. .. ~
,, , . : .. , : ' ~
105~04~
0,0-dimethyl-0-(3-methyl-4-rlitrophenyl)thiophosphate
(hereinafter referred to simply as fenitrothion),0,0-
diethyl-0-[2-isopropyl-~-methylpyrimidyl(6)]thiophosphate
(hereinaEter referred -to simply as diazinon), S-(1,2-
dicarboethoxyethyl)-0, 0-dimethyldithiophospha-te (hereinafter
reEerred to simply as malathion), 0,0-dimethyl-0-2,4,5-
trichlorophenylthiophosphate (hereinafter referred to simply
as ronnel), 0,0,0',0'-tetramethyl-0,0'-thiodi-P-phenylene)
thiophosphate, 0,0-diethyl-0-(3,5,6-trichloro-2-pyridyl)
thiophosphate, 0,0-dimethyl-S-[(~ -ethoxycarbonyl)ben~yl]
dithio~hosphate, 0-ethyl-0-(4-nitrophenyl)-phenylphosphon-
okhioate, O,o-dimethyl-0-(4-cyanophenyl)thiophosphate, etc.
The ratio of the phosphorus compound to the concentrate
composition is preferably in the range of 2 to 50~.
The amount of water in the concentrate composition
of the present invention is variable according to the content
of an insecticidal organo-phosphorus compoun~ in the concen-
trate composition but preferred amount is from 20% by weight
; to 96% by weight based on total weight of the concentrate
composition. If circumstances require, the water may contain
- an organic solvent in an amount of less than the water. Whenthe concentration of the insecticidal organo-phosphorus
compound in the concentrate composition of the present
invention exceeds 30%, it is preferred to use, in conjunction
with water, an organic solvent, preferably a polar organic
solvent, in an amount of below 15% based on the total weight
of the concentrate composition. The polar organic solvents
include ketones, cellosolve ethers, alcohols, etc. which have
a boiling point of, preferably, not lower than 80C. Suitable
polar organic solvents include, for example, cyclohexanone,
isophorone, ethyl cellosolve, methyl cellosolve, iso~ropyl
. .
;~ cellosolve,
~ - 6 -
:. : . ~ , ~ . . .
1 ~354~9
cyclohexclnol, diacetone alcohol, butanol, bu-tyl glycol and the
like. When dia~inon is used as the phosphorus compound, ketones
and cellosolve ethers are most preferable.
The s~lrface active agcnt useful in the present invention
depenclr~ on the nature of the insecticida] oryanic phosphoruc
compound. Usable surface active agents inc1ude nonionic surface
active agents, ionic surface active agents and ampholvtic
¦surface active agents. Polyoxyethylene alkylallylphenyl ethers
¦and homologues thereof are preferred due to a wide range of
¦application.
The surface active agent should be added in an amount
¦sufficient to make the insecticidal organo-phosphorus compound
¦soluble in said water, and the amount varies depending on the
¦kind and amount of insecticidal organo-phosphorus compound, and
¦also on the kind of the surface active agent itself. In
¦general, the preferred amount of surface active agent is in the
range of 0.4 to 4 times the weight of an insecticidal organo--
phosphorus compound and in the range of 2 to 30 % (by weight)
of the composition. -
~0 In practicing the present invention, the pH of the
concentrate composition should be adjusted in the range of 3.0
to 8.5 so as to prevent the organo-phosphorus compound from
being decomposed. The optimum pH of the composition varies
depending on the kind of the organo-phosphorus compound. For
example, with the malathion,the optimum pH is in the range o-f
- ~ 3.0 to 4.0 with the diazinon, the pH in the range of 6.5 to8.5 is suitable. When a number of other phosphorus compounds
are used, the composition in the pH range of 5 ~ to 6 .5 is
most stable.
- 7 -
:
',
: . , ,., , : .
~5~
When a relatively s-tabie insecticidal material
such as fen-thion, ronnel or the like i5 used for preparing
an aqueous insecticidal concentrate composition o~ the
present invention, the composition may often fal] on a
suitable range of pEI only with the use of a surface active
agent and water and it is not necessary to use any pH-
adjusting agent. With a relatively unstable insecticidal
compound such as diazinon, however, it is necessary to use
a buffer solution for pH adjustmen~ so as to suppress the
change in quality of the insecticidal compound per se witl
a lapse of time. In this case, the choice of the buffer
solution should depend on the nature of the insecticidal
compound. With the diazinon, for example, Sorensen's
buffer solution composed of an aqueous solution of potassium
dihydrogenphosphate and an aqueous solution of disodium
hydrogenphosphate, Kolthhoff's buffer solution composed of
an aqueous solution of potassium dihydrogenphosphate and
an aqueous solution of borax or McIlvaine's buffer solution
composed of an aqueous solution of disodium hydrogenphosphate
and an aqueous solution of citric acid is suitable for the ;
pH adjustment.
In some cases, the aqueous insecticidal concentrate
` composition of the present invention may advantageously be
improved in stability by addition of stabilizers. An epoxy-
compound is a suitable stabilizer for the a~ueous insecticidal
concentrate composition of the present invention. The epoxy
: :
compounds are for example, epichlorohydrin, butyl glycidyl ~;
ether, phenyl glycidyl ether, cresyl glycidyl e~her, meth-
- acrylic acid glycidyl ether, ethylene glycol glycidyl ether,
; 30 propylene glycol glycidyl ether, polyethylene glycol
diglycidyl ether, polypropylene glycol diglycidyl ether,
.
8 --
,:: , : : ~ ~ ' : `
.
~05~1349
butandlol diylycidyl ether, glycerol diglycidyl ether, etc.
These stabilizers are usually added in an amount of 0.5 to
3% by weigh-t of a final composition. Further, addl-tion of
sodium erythorba-te is effective, to some ex-tent, in
improving the stability and more effective when used in
combination with an epoxy compound. ~Iowever, the combination
is disadvantageous due to formation of coloring material.
The storaye stability of the aqueous insecticidal
concentrate composition of the present invention stands
comparison with those of known emulsifiable concentrates
using organic solvent. That is, the concentrate composition
of the present invention is found to have a decomposition
rate of an insecticidal organo-phosphorus compound as low as
3 to 5% when tested at room temperature (i.e., 5-34C) over
one year.
The aqueous insectlcidal concentrate composition
of the present invention is similar in nature to the known
emulsifiable concentrate compositions and can be applied in
the same manner and amount as the known compositions. In ~ ;- 20 comparison with the known emulsifiable concentrates, the- concentrate composition of the present invention exhibits
the same or superior level of insecticidal effect to noxious
insects such as larvae of mosquito, fly, midge, gnat, etc.,
when determined by an immersion method. Further, it has been
` found by a peroral test using larvae of Orthoptera and
Lepidptera insects having mandibles that the concentrate
` composition of the present invention has the same efficacy -
against the agricultural noxious insects as the known counter- ;
- parts. In addition, the concentrate composition of the
invention is not inferior in residual efficacy to concentrates
; of other types. As for peroral acute toxicity, ~0% - lethal
_ g _
- : ~ .,, -
0~
doses of -the concen'rate composition of the present
inven-tion for mice an~ rats is mueh more by about 30 to
50% than a known emulsifiable concentrate eontaining the
same inseeticidal organo-phosphorus eompound as the present
invention. This means -that the concentrate eomposition of
the invention is less harmful than the ~nown emulsifi~ble
eoncentra-ke. With regard to the percutaneous toxicity which
may present a problem upon applying an insecticide by :
sprinkling, neither mouse nor rat dies when the eoncentrate
eomposi~:ion of the invention is dosed at a level of 50~ -
lethal dose of the known emulsifiable eoneentrate. From
the above it will be elear that the eomposition of the
invention is mueh less noxious. In a skin-irritating test,
neither irritation nor inflammation is reeognized. Further,
an inhalation test reveals that the eoncentrate eomposition
of the invention is more harmless than lcnown emulsifiable con-
centration. A fish test also reveals that the concentration
of the concentrate. com.position of the invention required to
attain the same mortality of, for example, goldfish and red
killifish is about 1.5 to 2 times as great as that of an emul-
sion~type insecticide, thus showing ani~provement in toxicity.
The reduction of toxicity of the concentrate
.
: composition of the invention is considered to result from
omission or reduetion in amount of organi.e solvent inherently
possessed of toxieity and redueed synergistie toxieity of the
other eomponents due to the omission of organie solvent, and
also from reduetion in veloeity and amount of absorption of
inseeticidal component through skin and mucouse membrane due
to use of water as major proportion or all of solvent.
The eoncentrate eomposition of the present invention
exerts on a mitigated action on plants. So far as a proper ~ ;
:
, -- 10
,
1~5~
insecticidal compound is properly used depen~ing on the
kind of plantt the concentrate composition of the presen-t
invention is hard to bring c~bout the ill effects on plant.
Furthe~, the concentra-te composition of the present
invention is very conveniently used for the epidemic preven
tion purpose since it has little or no tendency to damage of
synthetic resin articles, rubber articles and coating surfaces
when compaLed with known emulsifiable concentrates.
The present invention will be particularly illus~
trated by way of the following examples, which should not
be construed as limitation thereof.
Example 1
- .
(1) Preparation of Insecticidal Concentrate Composition
of Invention (Hereinafter the aqueous insecticidal composition
of the present invention is referred to as "aqueous concen-
trate")
(a~ 5~ fenthion aqueous concentrate
: --
5 g of fenthion as an insecticidal organo
~` phosphorus compound and 15 g of polyoxyethylene dist~ryl-
methylphenyl ether (ethylene mol number = 10) as a surface
. . . ~ ~ . .
active agent were gradually added to 80 g of water with
stirring to obtain a uniform clear solutionO The solution or
preparation was adjusted to have a pH of 5~
(b) 5% fenthion emulsifiable concentrate
reference insecticide
::
:
5 g of fenthion, S g of a mixture of polyoxyethylene
nonylphenyl ether and sodium dodecylbenzenesulfonate, 20 g ;~
.~ ~
; of xylene and 70 g of kerosene were mixed together for
dissolution.
-~` 30 (2) Comparative Test Results
The above two insecticides were tested to determin~
- : :
.: - 11- . ' .
: ! '
:' '~
~1~5~04~
insecti^idal eficacy, acute toxity and s-tability. The
test results are shown below.
(a) Insecticidal Efflcacy
_ _ _ ___ __
Present ~<eference
Invention
.__ _ .
5%-fenthion 5%-emulsi Eiable
kind of insect and test method aqueous o~ncentrate
conoen trate
Houseflies (larvae) immersion method(l) 0.13-0.15 0.15-0.33 ppm
LC-50 ppm
~squitos (culex i~[mersion method 0.0018 ppm 0.0019 ppm
pipiens) LC-50
~Iouseflies (adult) filter ~er contact 3 hrs. & 36 3 hrs. & 22 min.
method ~cr-50 min.
~Iouseflies (adult) spray-dropping( ) 22 min. & 46 18 min. h 32
method (Nagasawa' s sec. sec.
Irethod) KT-50
Cockroaches plywood conta~) 7 hrs. 5 hrs.
(B.Germanica) method K~50 ~
20 Note:
(1) Immersion method: Each 5 ml of the insecticidal
solution diluted to different concentrations was placed in a
tall-skirted schale (i.e., small plate) having a diameter of
9 cm and a height of 6 cm, in which 30 worms to be tested were
` put. Thereafter, the schale was covered and allowed to
stand at about 25C for 24 hours for determinlng the LC-50.
- ~ (2) Filter paper-contacting method: A schale
having a diameter oE 9 cm and a height of 2 cm was covered
with filter paper on the bottom thereof . O . 32 ml of a 0 . 596
- 30 insecticidal solution was uniformly applied to the filter
paper by means of a 1 ml messpipet, in which 30 worms were
put. The schale was maintained at about 25C to determine
the KT-5 0 .
(3) Spray-dropping method (Nagasawa' s method):
A glass cylinder having an inner diameter of 20 cm and a
-- 12 --
, .
.
~05~L~49
height of 43 cm was covered at the top thereof with a glass
plate having a circular through-hole with a diameter oE 2.5
cm at -the center thereof and was placed on a glass plate at
the bottom thereof. Then, a tes-t pot containing 30 worms
was set in th~ glass cylinder. Thereafter, 0.5 ml of a 0.5%
insectieidal sam~le solution was sprayed Erom the circular
through-hole under a pressure of ~0 lb~in (i.e., 1.5 kg/cm2~.
10 seconds after the spraying, the glass plate at the bottom
of the cylinder was removed so as to permit the fine particles
of the sprayed solution to enter the worm-containing pot.
By the above procedure, the KT-50 was determined.
(4) Plywood contaet method: A 0.5% inseetieidal
sample solution was uniformly brush applied to a plywood
plate in an amount of 50 ml/m2, followed by allowing the stand
as it is for drying. Then, a circular glass ring having a
diameter of 9 cm and a height of 6 cm was placed on the
applied faee in which 30 worms were let, thereby determining
the KT-50. It will be noted that the LC-50 is intended to
mean 50~ - lethal concentration and the KT-50 means 50% -
lethal-knockdown time.
.
~ , ,'.', ~ '
.: ' ' ~'~:"'
'' ~
'-, ~. :
- 13 -
` .
-:.- . : - . . .: . .
:,: .. . : ;
,: ~ , ' : , . . , : . ., . : ; .
1~54049
(b) Acute Toxicity
__
kind of tcst animal and test method aqueous preparation emulsion for
of invention reference
~ . ~
p~roral dos~ ddy mic~ LD-50 approximate].y 2.0 ml/kg
(male) 2.8 ml/kg
" ddy mice LD-50 3.6 m:L/kg 2.5 ml/k~
(f~male)
" SD rats LD-50 4.98 ml/kg 2.9 ml/kg
(male) .
" SD rats LD-50 4.16 ml/kg 3.1 ml/kg
(female)
" Wister rats LD-50 3.3~ to ~.30 ml/kg 2.8 ml/kg
(female) .
_ ,, . , . ..
percutaneous ddy mi.ce LD-50 more than
dose (male) 9.93 ml/kg 10 ~l/kg
" ddy mice LD-50more than
: (female) 11.3 ml/kg 11.3 ml/kg
" Wister rats LD-50 approximately
. (male) 18 ml/kg 9.8 ml/kg
~ ~ ____ ,
Note: LD-50 means 50 ~ ~ lethal dose. In the toxicity test,
10 mice were taken as one group and 6 to 7 groups were subjected
to the test. With rats, 6 rats were taken as one group and
6 groups were used for the test. The observation was conducted
for 7 days or 14 days.
The peroral toxicity was examined as follows: an insecti-
cidal concentrate was forcibly dosed into the stomæh of a test
animal by the use of a metal stomach probe. While, the
` 10 percutaneous toxicity was examined by shaving the back of a
test animal and applying an insecticidal concentrate to the
shaved back.
;
. The percutaneous toxicity of the aqueous insecticide of
the invention against the mice ~male and female) was as follows:
no mice died when the aqueous insecticide was dosed in amounts
of 9.93 ml/kg and 11.3 ml/kg to the male and female mice,
', . .'
:~
~.i ~ ,
- .. .. . . .
respectively, without evidencing clear toxic symptons.
From this it is assumed that the LD~S0 i5 far greater than
the above-indicated amounts.
(c) Decomposition Rate of EEfective Ingredient
During Storage
_ Present _
invention Reference
storing conditions 5~ fenthion 5~ enthion emulsi-
concentrate fiable concentrate
_ _
40C, 4 weeks 1.12~ 1.03%
40C, 8 weeks 2.63~ 2.72
room temperature, 3.30% 3.15
one year (S-34C)
Note: ~he test was conducted by placing the sample in a
hermetically sealed glass bottle and keeping the bottle in a
light-shielded place of the predetermined temperature.
(3) Discussion
As for the insecticidal efficacy, the aqueous
~ concentrate of the present invention is equivalent or rather -
; 20 superior to the known emulsifiable concentrate with regard -~
to larvae o-f Houseflies and Mosquitoes, but the latter is ;~
superior with regard to adult of Houseflies, Mosquitoes and -
German cockroach. However, the insecticidal efficacy of the
~ aqueous concentrate of the present invention is within a
i range enough to stamp out the noxious insects when the insec~
;~ ticide is applied in a standard amount. ;~
There is little difference between the aqueous
concentrate of the present invention and the known emulsi-
` fiable concentrate ;
~ 30
.~ ~ '' ' .
.
- 15 -
:. . . . . .
:, . .- . ' ;: ' ` ' - , -
1054049
concerning the decomposition rate with the lapse of time. As
for the acute ~oxicity, the aqueous concentra-te of the present
invention is less harmful than -the known emulsifiable concent-
rate. Especially, the reduction in percutaneous toxicity is
S considerable. ~s a whole, the aqueous concentrate of the
present invention i5 similar in insecticidal efficacy and
stability to the known emulsifiable concentrate and has reduced
toxic characteristics.
Exam~le 2 (Comparative Test for ~esidual Efficacy)
(1) Tested Insecticides
(a) Aqueous 5 ~ fenthionaqueous concentrate prepared in
the same manner as in Example l~ (a).
(b) 5 ~ fenthion emulsifiable concentrate prepared in the
same manner as in Example l-(i)-(b).
(2) Tested insect: Adult of houseflies
; (3) Test Period: July 23, 1973 - August 16, 1973
- (4) Test Method: The respective concentrate were diluted ten
times with water and were each sprayed over the inner surfaces
of a room in an amount 50 ml/m2. 1, 5, lO, l~ and 25 days
after the spraying treatment, each 200 flies were let in the
room and the xoom was closed. 24 hours after the closing, the
number of dead flies was examined. In the test results, the
~ term "closed division" is intended to mean that the windows in; the room were all closed during the course of the test, while
;; 25 the term "opened division" means that the windows were all
opened during a period between an examined day and a next
~; ~1etting-in day
,. , . .
.'
~ -
16 -
''' .
~.
1054049
(5) Test Results
¦ Mortality (%) in a day in closed divis.ion
. ~ ~
. ex~mined date7/23-7/2~ 7/27-7/28 8/1-8/2 8/9-8/10 8/16-B/17
l .-- . .
rreSent 5~ fenthion
invention aqueous 100 100 100 100 100
l concentrate .
I -, ~ ~ , . _
Reference 5% fention
emulsifiable 100 100 100 100 100
concentrate
1~ -- -- - - --- - - - ----- - - - -
i room tempe~a- 30 O- 29 5-29.8- 31.5- 31.0-
~: l ined day (C) 31.0 31.030.5 33 0 31.2
. . _ ~
~` I ,
¦ Mortality (~) in a day in opened division
I ,~
I . examlned date 7/23-7/24 7/27-7~23 8/1-8/2 8/9-8/10 8/16-8/17
:~ _ _ . - . '. .' `'.
. Present 5% fenthion
invention aqueous 100 100 100 100 100
concentrate . . .
. _ __ __ __
Reference 5% fenthion
I emulsifiable 100 100 100 100 100
.~ .... . . concentrate . .
_ oom ~ ~ ~
~:. temperature 30 5- 30 5- 28 7- 31 O- 31.5- : -
~: of examined 32.0 32.0 30.5 35.1 33.0
_ _ . _ . ____ L . _ ¦
,~ . ',' E ~ (Comparative Test For Toxicity Against Fish) .
(1) Tested Insecticides l :
(a) 5 % fenthion aqueous concentrate prepared in the
- same manner as in Example l-(l)-(a). I
(b) 5 % fenthion emulsifiable concentrate prepared in the
same manner as in Example l-(l)-(b).
. (2) Tested Fish: Adult of red killifish
,.~ . .
. .
~ . - 17 -
,. .
:: . - 1':'--~ 7
:' . . : ., ' ' ' , ' .. ~ ' . :: . . . .
': '' . ' ', '' ' ' . ' ' ' . : :
1115~049
(3~ Test Method: A number of red killifish were kept for
1 - 10 days, among which a predetermined number of sprightly
fish with almost the same len~th were chosen for the test.
5 - 10 fish were placed in an enameled container(30 cm x 20 cm x
12 cm in depth) containing 4000 ml of an insecticidal solution
Wit}l a predetermined concentration. 48 hours a~ter contact
with the insecticidal solution, the number of the dead was
counted. The dead fish was removed every 12 hours. The test
was repeated 3 to 15 times at each concentration. During the
test, the enameled container was immersed to a certain level
i in a concrete vessel over the top of which well water invariab]y
overflowed so as to maintain the solution at a temperature as
constant as possible.
(4) Results -
Mortality of red killifish 48 hours after
contact with insecticidal solutlon
:, ' , , , . , .__ ______
.~ ind of Present invention Reference
:` , \ \ lnsecti-
\ \ cide 5% fenthion aqueous ~
\ \ concentrate emulsifiable concentrate
oncen-\ ` . - _ ~ ~
tration \ Number of Number of Mortality Number of Number of Mortallty
\ tested dead fish tested dead fish
\ fish fish
. .- ... .. . _ . ~ . . _ ~ . ~ ...... ..
3.0 ppm70 32 45.7 _ _ _
. . 2.0 85 15 17.6 85 36 42.4
.. 1.0 65 ~ 6.2 85 7 8.2
; 0.5 70 0 0 100 8 8.0
. 0.25 _ ~ _ 30 0 0 ~:
:', ` _ _ _ _ _ ._ ........... _ :'
From the above results, it will be understood that the
~` aqueous concentrate of the present invention is far lower in
.,.
. .
- 18 ~
-:
,:' ' ' . '~, ' ' : ~ -
105404~ 1
toxicity agalnst fish than the known emulsifiable concentrate.
Example 4 (Cutaneous Irritation Test)
._
(1) Tested Insecticide
5 ~ fenthion aqueous concentrate prepared in the same
S manner as in Example l~ (a).
(2) ~ested Animals
Male rabbits each having a weight of 2.0 - 3.0 kg were
used, six for reference and another six for application of the
testing insecticide.
(3) Application Method
The back of each rabbit was shaved in a circular shape
of a radius of 2.0 - 3.0 cm. 24 hours after the shaving,
remaining fur was fallen off by the use of a depilatory cream.
2 days after the falling-off, O.S ml of the insecticide to be
tested was uniformly applied to the back.
(4) Estimation
The degrees of rubefacient and scabbing formation and also
of edema were estimated in accordance with the Dvaize method
and were expressed in terms of marks. The intensity of the
cutaneous irritation was determined from the average value of
the marks obtained 24 hours and 48 hours after the application.
(5j Results
As will be clear from the following Table, the 5 ~i
fenthion aqueous concentrate has a final estimation mark of
0.33 and is thus found to give little cutaneous irritation
aotion on the bits.
. ' .
.. ~ -' 19 -
'.~ . .
1'''1''
1~5~9
-
- Kind of Days 1 2 3 4 5 6 7 Final
ect:cide lo.l _
10' ~_ 1 ~
.~ 5% fenthion
aqueous~ 3 _ _ _ _ _ _ _ `
~c~nt ~ ¦ 4 2
' "
Example 5 (Preparation of Various Aqueous Concentrate and ~ :
Insecticidal Efficacy and Stability Thereof)
(1) Preparation of Insecticides
(a) Diazinon insecticide of invention
- 1. 5% diazinon aqueous concentrate ~. - .
. .
- 5 g of diazinon as an insecticidal organo-phosphorus ; :.
:............ compound, 14 g of polyoxyethylene diphenylmethylphenyl ether
(mol number of ethylene = 12~ and 0.7 g of sodium lauryl-
sulfate as a surface active agent were mixed together. Then, ~;
79.3 g of a mixture (having a pH of 7.0~ of an aqueous 1/20
mols potassium dihydrogenphosphate solution and an aqueous
1/20 mols disodium hydrogenphosphate solution in a mixing
ratio by volume of 1:2 was gradually added, as a pH adjusting
agent, to the above mixture with stirring, thereby to obtain
: a uniform clear solution. Finally 1 g of polyethylene glycol
.
.
l~S~
diglycidyl ether as a s-tabili~er was added -to the solution
to obtain 5% diazinon aqueous concentrate.
2. 5~ diazinon aqueous concentrate
5.~ g o~ diazinon, ].0 g oE polyoxyethylene non-
~lphenol ether (having an ethylene mol number of 10) and
5 g o sodium al~ylnaphthalenesulfonate were mixed together.
To the mixture was added a mixture (having a pll of 7.4) of
an aqueous 1/15 mols potassium dihydrogenphosphate and an ~ .
aqueous 1/15 mols disodium hydrogenphosphate solution in a
mixing ratio by volume of 1:4 with stirring to obtain a -~
~ uniform clear solution, to which was further added 0.2 g of
: sodium dehydroacetate as an antifungal agent thereby obtaining
5% diazinon aqueous concentrate. :~
3. 20~ diazinon aqueous concentrate
23 g of diazinon, 20 g of polyoxyethylene nonyl-
phenol ether (having an ethylene mol number of 10~ and 7 g
of sodium alkylnaphthalenesulfonate were mixed together. To
the mixture was added 47.9 g of a mixture (.having a pH of
~ 7.8) of an aqueous 1/10 mol potassium dihydrogenphosphate ~;; .
and an aqueous 1/20 mols borax solution in a mixing ratio .:
~` by volume of 1:1 with stirring to obtain a uniform clear
solution, to which were added 2 g of a stabilizer, phenyl
. glycidyl ether and 0.2 g of an antifungal agent to give 20%
:` diazinon aqueous concentrate~ :
: . : .
.~ 4. 45~ diazinon aqueous concen*rate
... :
. 45 g of diazinon aqueous concentrate, 15 g of
:,
polyoxyethylene nonylphenol ether ~.having an ethylene mol
number of 10), 5 g of sodium al~ylnaphthalenesulfonate and ;~ :
10 g of ethyl cellosolve as an organic solvent were mixed
. 30 together. To the mixture was further added 21.~5 g of a ;.
` mixture (.having a pH of 7.4) of an aqueous 1/5 mols potassium ~:
- 21 ~
.: . .. - , . ~ . , - :
.. . . .
~05~ 9
dihydrogenphosphate and disodium hydrogenphosphate in a
mixing ratio by volume of 1:4 with stirring to obtain a
uniform clear solution. ThereaEter, 3 g of a stabilizer,
phenyl glycidyl e-ther and 0.05 g of an an-tifungal agent,
henxoisoth:iazolone, were added -to the solution to obtain
45% diazinon aqueous concentrate.
(b) 10~ fenitrothion aqueous concentrate
10 g of fenitrothion as an insecticidal or~ano-
phosphorus compound, and 20 g of polyoxyethylene distyryl-
methylphenyl ether (having an ethylene mol number of 10),
were mixed together. To the mixture was gradually added,
as a pH adjusting agent, 69 g of a mixture (having a pH of
6.1) of an aqueous l/20 mols potassium dihydrogenphosphate
and an aqueous 1/20 mols disodium hydrogenphosphate solution
with stirring to give a uniform clear solution. Finally,
l g of a stabilizer; polyethylene glycol diglycidyl ether,
~ was added to the solution to obtain 10% fenitrothion aqueous
; concentrate.
(c) 10% ronnel aqueous concentrate
15.4 g (with a pure ronnel of lO g) of ronnel
solution (having a purity of 65% and being in the form of
a methylene chloride solution) as an insecticidal organo-
phosphorus compound and 20 g of polyoxyethylene distyryl-
methylphenyl ether having an ethylene mol number o~ lO)
were mixed together, to which 64.6 g of water was gradully
added with stirring to give a uniform clear solution. The
solution was adjusted to have a pH of S-6.
.. ~ ;
~2
':
~ ~ 22 ~
:: ,
11)54049
(2) Insecticidal efficacy and stability
The i~secticidal efficacy and stability of the respective
insecticides are shown in Table below.
.`
Insecticidal Efficacy
. . ....... .. ,.. , .. ... ,.,........ ,........... .,
r___ _ , _ _ v _
Kind of insecticide ~`
T e s t ;. ~ t ~ ~ ¦ ( b ) ( c )
Diazinon Fenitrothion Ronnel
_._ . __
Larva of Immersion 0.036 ppm 0.0098 ppm 0.025 ppm
Mosquitoes method LC-50
Adult of Spray-dropp-
~ houseflies ing method 15 min. & 29 min. & 20 min. &
;~! (Nagasawa' 15 sec. 48 sec. 20 sèc.
method) KT-50 ' ~
,, _ ~ . - I
`, ' ".,'
Note: The test methods are the same as in Example 1-(2)-(a),
with the abbreviations, LC-50 and KT-50, having the same
meanings as defined in Example 1-(2)-(a), respectively.
:' .,
Decomposition Rate Of Effective
Component During Storage
:' . . . . . ................. ............................
-~ ~ ind of insec-
,~ ~nt Dia~inon thion Ronnel
Storing ~ nSec ~ _ ~ _
conditions \ ~ ~ 1 2 3 4 ~
Room temperature 4.0 % 2.5 %3.0 % 4 r 0 % 4.2 % 2.8 %
, (5 - 34C~
one year
. . . ___ ., _ _
Note: Samples were each placed in a closed glass bottle and
stored in light-shielded box. '
.'~', .
.
`` ` - 23 -
..
ir~F- ~
.. ...
.
~. , . :, , . , - , ~
.
