CA1043255A

CA1043255A - Solid pesticide compositions

Info

Publication number: CA1043255A
Application number: CA231,370A
Authority: CA
Inventors: Claude Denninger; Jean-Noel Tabet; Michel Joly
Original assignee: Sogemaric Sa Gestion Et De Marketing Pour Industries De Con Sommation Ste
Current assignee: Sogemaric Sa Gestion Et De Marketing Pour Industries De Con Sommation Ste
Priority date: 1974-07-15
Filing date: 1975-07-14
Publication date: 1978-11-28
Also published as: JPS5135438A; AU8282475A; AU499544B2; AT348827B; NO752244L; IL47552A; IE42919L; DE2531426A1; NL7508269A; DK318875A; IL47552A0; NO144689C; BR7504455A; SE7508001L; AR218846A1; JPS5852962B2; IE42919B1; NO144689B; CH596769A5; ES439450A1

Abstract

ABSTRACT
The invention relates to a solid phytosanitary compo-sition compacted as a single dose for argicultural application and progressively disintegratable by contact with water, said composition containing at least one phytosanitary active material, at least one filler and at least one wetting agent, dispersant or deflocculant which is suitable for wettable powders, wherein the filler is not hydrophilic and wherein the composition contains a solid, water-insoluble disintegrating agent. The solid pesticide compositions are intended for agricultural application by pro-gressive disintegration by water.

Description

-~0~3ZSS
This invention relates to solid pesticide compositions for agricultural application which are intended to be pro-gressively disintegrated by contact with a stream of water.
More particularly, the invention relates to solid pesticide compositions for use in the treatment of amateur gardens by a new method which, so far as the user is con-cerned, eliminates the need for any complicated and/or dangerous handling of pesticides.
The treatment of trees, ~egetables or flowers growing in amateur gardens involvas specific problems due to a certain level of ignorance among amateur gardeners of the potential dangers presented by phytosanitary products.
:~ .
The plants treated, in respect of which it is ess- `
ential to keep to the stipulated doses on account of the phyOtOxicity phenomena to which excessive doses can give rise, are the primary concern becau~e, very often, the amateur gard-ener has a tendency to increase the dose in the hope of ob-taining a better effect wherea~, in fact, increa~ed doseq can cau~e irreparable damage to tha plants.
Another disadvantage of overdosage is the release lnto the atmosphere of excessive quantities of pesticides which are incompatible with protection of the environment and with legislation on the use of pesticides. :
Another danger, this time involving the user, is the need for difficult manipulation of ~nall quantities of more or less toxic products which very often are in the form of extremely fine powders which are readily blown away by wind and, for~ this rea~on, are difficult and, in some cases, dangerous to handle.
Accordingly, it is extremely important for these three '~ :

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reasons to develop and make available to amateur gardeners formulations and devices which eliminate the disadvantages referred to above.
The present invention responds to this need by pro-viding a formulation in the form of single compact doses.
This type of formulation eliminates the dangers of overdosage but, to give satisfaction, it must be uniformly dis-integratable in dependence upon the volume of water with which it is brought into contact. In other words, the quantity of disin~egrated material must be substantially proportional to the volume of water. I ~; -This effect is obtained in known manner in the pharmaceutical industry in the form of tablets which are ob- -tained by the compression of a powder with various additives, especially binders. However, they cannot be used for the application of pesticides to plants on account of the very ~;
small quantities of disintegrated material per litre of disin-tegrating liquid, because the active material has to be applied to the plants in quantities suficient to obtain the required e~fect. ;~
The lnvention attempts to provide a solution to this ;
problem. The invention relates to solid, compact, phytosanitary compositions for agricultural application which are intended ' to be progressively disintegrated by contact with a stream of water and which are distinguished by the fact that they contain, in addition to the active phytosanitary materials and, optionally, wetting agents and/or dispersants of the type normally used in the production of wettable powders, a solid water-insoluble disintegrating agent. If the wettable powder . .
is intended to contain a solid ~iller, the filler used should : . .
"~

~,`; -2-~¢~43255 not have hydrophilic properties.
According to the present invention there is provided a solid phytosanitary composition compacted as a single dose for agricultural application and progressively disintegratable by contact with water, said composition containing at least one phytosanitary active material, at least one filler and at least one wetting agent, dispersant or deflocculant which is suitable for wettable powders, wherein the filler is not hydro- -philic and wherein the composition contains a solid, water- -insoluble disintegrating agent.
The invention also provides a process for the prep-aration of a phytosanitary composition of the above type, comprising dry-mixing at leas~ one phytosanitarily active material with at least one non-hydrophilic filler, wherein a solid water-insoluble disintegrating agent is added during mixing, and wherein the mixture is compressed into single doses under a pressure of from 50 to 1000 bars. ~ `
In the context of the invention, a solid non-hydrophilic filler is a powder-form solid without any tendency to hydrate in aqueous medium because a composition containing a hydrophilic filler in contact with water gives a tacky paste which slows down disintegration to a considerable extent.
In the context of the invention, a "phytosanitary active material" is essentially a herbicide, insecticide, fungicide, growth regulator, bactericide or fertilizer which may be applied to plants or seed. According to the invention, the compositions may contain one or more active materials which, together, may represent up to 80% by weight of the composit-ion. ,~
In the context of the invention, the solid disinte- -., . :. . ' .':
', ; ~, ~ ' ' ' .

~ 43Z~
grating agent should be insoluble in water which does not mean that it should not be hydratable or swellable in water. This ~-is the case with starches based on such vegetables as corn, -rice, potatoes which give good results, although maize starch is preferred. However, this list is by no means complete and it is possible to use compounds with an equivalent function due, for example, to a polyholoside structure similar to that of starch. - -The disintegrating agent must be present in a sufficient quantity to ensure that the rate of disintegration, i.e. the quantity of solid active material disintegrated ~ -per litre of water, is high enough to enable the plants to be effectively treated. ;
By contrast t an excess of this additive causes -excessively rapid disintegration. Generally, quantities of from 20 to 60~ by weight of the composition are perfectly suitable. However, this i~ by no means limitative and quantities outside these limits may be used provided that an adequate rate of disintegration, for example approximately ! ' '

2 to 15 g/l, is obkained, In order to prepare the compositions according to tha inv~ntion, a mixture of one or more active phytosanitary ' .: .
materials (herbicides, growth regulators, insecticides, fungicides) in solid form, i.e. either the active material alone if it ls solid, or impregnated on a solid, inert support if it is liquid, is mixed with the additives, wetting agents, dis~
persan~s of the type commonly used in the production of wett-able powders, and with the non-hydrophillc filler and the disintegrating agent described above. The mixture is homo-genised and then compressed into tablets or pellets of the -~
i;,~.,: ! ;

~43255 required shape under a pressure in ~he range from 50 to 1000 kg/cm2 and preferably under a pressure in the range from 100 to 600 kg/Cm2.
The compositions according to the invention are preferably prepared in two stages: in the first stage, the active materialsJ additives and fillers are mixed, optionally with grinding or micronisation, and in the second stage the premix thus obtained is in turn mixed with the disintegrating agent in the absence of any grinding effect. In this way, the shape of the starch grains is not altered by deformation or fragmentation whichJ as will be seen in the Examples, considerably improves the concentration of active material in ;
the sprayed liquid and the uniformity of the disintegration rate.
The compact compositions according to the invention may be used in the form of cartridges in appliances of J for example, the long-barrel spray gun type used by amateur gardeners, comprising a mixing device in which the stream of water comes into contact with the suitably shaped surface o the composition during the compression stroke.
Devices of this type may vary according to whether the compact composition or cartridge has a variable or constant disintegration surface. -One example of a device of the first type is the device described in German Patent Specification 1J211J6O3J
whilst the device described in Canadian Patent Application 228,114 is an example of the second type of device.
The following Examples illustrate the compositions according to the invention and the process for their preparation. , .: ~ , . . . ; . , ~

1~)43ZSS
EXAMPL~ 1 An insecticide mixture with the following composition (by weight) is prepared: ~
Malathion: S~ 2-di- ethoxycarbonyl -ethyl)- ~ -dimethyl-phosphorothiolothionate ................................ 15%
Lindane (~-isomer of hexachlorocyclohexane) ...................... 4%
maize starch .................................................... 30%
talcum ......................................................... 24.5%
kaolin ........................................................... 4%
absorbent silica ................................................ 13%
10 naphthalene sulphonate ~wetting agent) .......................... 3.2% j ~ -condensate of 10 molecules of ethylene oxide with nonyl phenol (wetting agent) ............................... 0.3%
calcium lignosulphate (deflocculant) ~ 3%
sodium isopropyl naphthalene sulphonate (dispersant) ..................................................... 3% --The malathion~ being liquid, is first applied by impregnation to the silica. The mixture of active materials, starch and additives is homogenized for 30 minutes in a paddle mixer and then compressed under a pressure of 125 bars -into cylindrical pellets weighing approximately 10 g. Pive of these pellets are successiv01y introduced into the magazine o a mixing device connected to a spray nozzle of the type described in Canadian Patent Application 228,114, in which the pesticide cartridge has a constant disintegration surface.
The device is connected to the running water supply, followed by spraying in fractions of 500 ml into a graduated vessel. ~ -The test is repeated three times, which substantially corresponds ta exhaustion of the cartridge. The contents of each vessel are evaporated and the dry extract weighed.
, The following results are obtained in this way, representing an average value based on the five cartridges.

., . .~ ,.
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. .
Volume of water Weight of solîd Ratio of weight to collected in ml material collected ~olume (dis- . -:
in g integration rate in : ~
,......... ~ , . ,_ 500 2.7 5.40 1000 5~3 5.30 1500 ~.2 5.45 2000 10.5 5.25 .

____ _ . _ This Table shows, on the one hand, the high level of uniformity of the quantity of solid material disintegrated per volume of water and, on the other hand, that the dis~
integration rate amounts to between 5 and 5.5 g/l.

A fungicide mixture with the following composition - .
(by weight) is prepared: .
dicofol (2,2,2-trichloro-1, 1-di-~4-chlorophenyl)- ..
ethanol) ......................................................... 12~o ..
rice starch ...... ................. ,................ ,............. 3G% .
talcum ........... ....,............ ,................ ,.,........... 42% :~
: . . .
sodium naphthalene sulphonate ............................... .2% ~ .
potasslum isopropyl naphthalene sulphonate .................. .3~0 kaolin ...................................................... .3% ; ~.absorbent silica ............................................ .~%
The mixture is homogenized, compressed and tested in the same way as in the pre~eding Example, The results ~:
obtained are ~et out in the following Table: ~

' ..~ ' : ~ .

. . . .. , . , . .. . ~ , ~ ~ ,, ~L~43~SS :
Volume of water Weight of solid Ratio of weight to collected in ml material collected volume (dis-in g integratk)on rate in _ . . ~ _ _ ~ ~ . .
500 1.9 3.~
1000 3.4 3.4 1500 5.6 3.7 2000 7.~ 3.9 In this case, tha quantity of material disintegratedflmounts to between 3.5 and ~ g/l, disintegration taking place with a high level of uniformity.
EXAMPLE~
A fungicide mixture with the following composition (by weight) is prepared:
manebe (manganese ethylene~l, 2-bis-dithio- `
carbamate) ............................ .................. 47%
benomyl (methyl-N-(l-n. butyl carbamoyl-2-benz- -imidalzole)-carbamate)................. ...............,,.,.,,.... ,,.,.... 6%
pOtfltO ~tarch ..... ...... ,............ ........................ ...... 39%
glucose ......... .. ...... ..................... ............ 5%
i~opropyl naphthalene sulphonate ......... ............... 2%
~0 naphthalene sulphonate ................... ............... 1%
The mixture is homogenized andthen compressed under a pressure of 165 bars. The pellets obtained are then tested ~;
in the same way as in Example 1. The results obtained are set out in the following Table:

" "" `"', '' .
.

, .......

~09~3~SS
... .. .. _ .. ...
~olume of water Weight of solid Ratio of weight to collected in ml material collected volume (dis-in g on rate in 500 2.6 5.2 1000 5.5 5.5 1500 g.3 5.55 ~' ~000 lO.g 5.4 _ _ v~ ~__. ~_ This Table shows that the disinte~ration rate amountsto around 5.3 g/l with a high level of uniformity.

The influence of grinding upon the disintegration rate is illustrated by the following test:
Three separate fungicide formulations with the following common composition (by weight) are prepared:
manebe (man~anese-ethylene-bis-dithio-c~rbamate), ~5% commercial grade ......................... 23.5 ~ ` `
triturated sulphur .................. ............ ,...... ... 30.0 malze starch ........ ,............... ...~........ .... ... 21.5 , talcum .... , ...... ,,....... ,,.. ,... ,,...................... 25 These ~ormulations, designated F , F and F , are 20 prepared in two stages, the first stage being common and - ;
comprising mixin~ the manebe, the sulphur and the talcum `
in a blade mixer. In a second stage, the premix is in ``-turn mixed for 30 minutes with maize starch `
- in a microniser in the case of F (95~0 of the par~icles smaller than 10 microns), - in an Alpine type mill in the case of F (95% of the particles smaller than 50 microns), - in simple paddle mixer in the case of F (particle si~e not reduced).

9 ,,X~

:~)43~55 Each of these compositions is then converted under a pressure of 487 bars into compact cylindrical cartridges 28 mm in diameter each weighing 20 grams.
These cartridges are then covered by thermoforming in vacuo with an 80 microns thick polyethylene film and introduced into a spray gun for amateur gardeners of the type described in Canadian Patent Application 228,114 in sùch a way that the disintegration surface is constant. The spray gun is connected to a water supply under a pressure of 3 bars so as to obtain a throughput of about 0.4 to 0.5 litre/minute.
The water inlet is opened by means of a trigger so that the cartridge is disintegrated and the disintegrated substance sprayed in the form of a fine mist. The average volume required to exhaust the cartridge and the standard deviation in litres for a series of tests are then determined, each figure being the average result of 8 tests.
The results are set out in the following Table:

Formulation Mean volume Standard deviation Throughput in litres in litres l/minute - .~ .. .
Pl 4.32 0.44 0.42 ~`

P2 2.87 0.38 0,44 ;

P3 2.07 0.20 0.44 :., . :
This Table clearly shows that, at a constant throughput, ormulation Fl containing micronized starch requires a disintegration volume more than 1.5 times greater than that required for formulation F2 and more than twice that required for formulation F3. In other wordsl for the same composition~

formulation F enables twice the quantity of active material to be applied to the plant which ls of particular advantage for ~ -. ". . . ~ ,.
~: . `~, .
;"': ~',' ' -10- , ~ ~", 1043Z?SS
gardening formulations which, since they are o~ten of a multipurpose character, have to contain more active material.
In addition, notation of the standard deviation shows that the reduction and, a fortiori, the absence of a grinding effect during mixing of the starch with the premix of active :-materials considerably improves the uniformity of disintegration. .
These results show that, according to khe invention, .
it is important that the starch grains should not be fragmented by grinding. Accordingly, the apparatus used for mixing the active materials and starch must be able to carry out this operation without altering the shape and size of the grains. :.
Similar results were obtained with the following ;: :
eompositions: ` ~
EXAMPLE S ~ -CQPI~ir~ed. ~C~,Ci~e/fUrA~1Ci~QCOnIPOSit~n ~5% eommereial-grade manebe ............................. 23.5 tritura~ed ~qulphur ..................................... 30.0 eommereial-grade 5-~6-chloro-2-oXoben2-oxazolin-3-yl)-methyl dlethyl phoqphorothiolo-thlonate ~?iphosalone) ...............,................... 6.o taleum .................................................. 12.5 :.
maize starch .~.......................................... 2~.0 mean volume: 1,99 1, standard deviation: 0.14 1 . ~.:
¦ EXAMPLE 6 ecticide composition eommereial-grade phosalone ..,.,...,...,,.., ..,...,., 6.0 ab~orbent synthetic silica .................,,.. ,.. ,...... 6.0 kaolin coloured by methylene blue .... ,....,,,..... ,...... 3.0 taleum .....................~............................ 35.0 ~rice starch -----------------------?------------------- ~0-0 ~ ' ,, 100, 0 ' -' 'j ' .': .',' ' 32~5 mean volume : 2. o6 1 ~ standard deviation: 0.15 1 EXAMPLE~
Fun~icide composition ~% commercial-grade 2,2,2-trichloro-1, l-di-(~-chlorophenyl)-ethanol (dicofol) ,................. ,. 5,9 absorbent synthetic silica ............................. 4.1 kaolin coloured with methylene blue ................... 32.0 maize starch ..........,............................... ~.0 100. 0 ., mean volume: 1.92 l,s~andard deviation: 0.12 1 EX~jPLE
~9~b~ de/~U~ Q.composition Y-isomer of hexachlorocylcohexane (lindane), .
95% commercial-grade ................................... 2.3 ~5% commercial-grade methyl-l-naphthyl ..
carbamate (carbaryl) .. ...........~........................ ~9 zinc ethylene-l, 2-bis-dithiocarbamate (zinebe), 93% ......... .................................. 21.5 ::triturated sulphur ........................................ ... 30.0 :
talcum .................................................... ... 10.0 `
.
potato starch ............................................. ... 27.~ : .`
100.0 mean volume: 2.05 1, standard deviation 0.09 1 .
_XAMPLE~
Q_QQmEQ~ L~ YiDQ ::
copper oxychloride contai.ning 53~0 of copper metal .................................................. 2~.0 : .
93~0 commercial-grade zinebe .................... ,,............ 5,~
~5% commercial-grade manebe ... ~..................................... 5.9talcum ................................................. ............. 10.0 corn starch ... ,~....... ,.......................................... ,, _~0.7 100.O ':
maan volume: 3.~0 l,standard deviation: 0.15 1 .
:;.~' . .

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~)4;3~SS :
In this caseJ the cartridges weigh 40 grams but are .
otherwide identical.
EXAMPLE 10 "~
Selective herbicide_f,,or ~he,treatment of ~rass sodium salt of 2, 4-dichlorophenoxy acetic acid -~
(2,4-D) .. ,............. ,.. ,...... .,....... ~............ ., 5.5 :' sodium salt of 2-methyl-~-chlorophenoxy propionic acid ~..... ,,............ ,.. ..,.......................... ...2~.0 maize ~tarch ...... ~.~........... ~.~.O.. ~....... ~.~.~... ~.... ~. 41.0 .:, 10 tAlcum ...... .~............................................ .._31.5 : :
100. 0 A 40g cartridge disintegrating into 4 litres enables- : -40 square meters of grass to be treated. ' ~ :
mean disintegration volume: 3.90 1, standard deviation: 0.21 1. '-'', ' EXAMPLE 11 '' _.
e herbicide for the treatment of ~rass sodium salt of 2,4-dichlorophenoxy acetic acid .............. ~........................................ 11.0 .
kaolin ............ ,......................................... 3.0 ~
talcum .................................................... 35.5 ',..... ' ',' 20 maize ~tarch ................................................. 50.0 .
loo o A 20 g cartridge disintegrating into ~ litre~ enables . , 20 square metre~ of grass to be treated.
average disintegration volume: 2.06 1, standard deviation: 0.1 1.
EXAMPLE 12 ,, .' _ .. . .
_er~ 3~ ~L .lea,f appllcation : , diammonium phosphate ........................~............. 4.05 urea ...... ~.. ,..............~.............. ~.................... 2.10 ;' ' potassium nitrate ...........................~............. 3.67 ~, . , oligoelements (B ? CU, Fe, Mg, Mn, Mo, Zn) ............. ... 0.1~ ' ~tarch ................................................. ... 20.0 talcum.~... ,..................................................... 70. Q -100.0 ' 13 ~: .
' ,- , .
.. .
,, " , " ", , " ,,, ~ , , ", " ", ,, ,, , , ., , , ... . ~ .. , . . .. . . .. . . -~ . .. . , . , . , . . . - ., . , . . - . ., , . , . . - . . .

~)43ZS5 ~
A 20 g cartridge disintegrates on average into 2015 litres with a standard deviation of 0.2 These Examples are intended to illustrate insecticide `
and/or fungicide or herbicide compositions, although compositions with a growth-regulating e~fect on plants and,in addition, the same properties asthe compositions described also form part of the invention.
The compositions of Examples 5 to 12 do not contain any wetting agent and/or dispersant and/or flocculant, because experience has shown that these additives are not indispensable and are only useful when the active material is extremely hydrophobic.
These Examples illustrate the remarkable properties of the compositions according to the inventionJ namely their ability to di~integrate uniformly at an adequate disintegration rate.
These compositions may thus be uqed with a variety of ~`
phyto~anitary active material5 for the treatment of cultures of all kinds, more especially trees, vegetables and flowers.
This a~pplication, combining simplicity, convenience and sa~ety both for the user and for the plant, makes the compositions particularly suitable for the treatment of amateur gardens.
'''' ' ~ ''.' ., ; . ':. ."'' ~... ...

` 14

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A solid phytosanitary composition compacted as a single dosage unit for agricultural application, and is progressively disintegratable by contact with water, which composition contains at least one phytosanitarily active material, at least one non-hydrophilic filler, and a solid, water-insoluble, disintegrating agent.

2. A composition as claimed in claim 1 additionally containing at least one surfactant of the type normally used in the production of wettable powders.

3. A composition as claimed in claim 2, wherein the disintegrating agent is a starch.

4. A composition as claimed in claim 3, wherein the starch is not ground.

5. A composition as claimed in claim 3 or 4, wherein the disintegrat-ing agent is maize starch.

6. A composition as claimed in claim 1, wherein the disintegrating agent is present in a quantity of from 20 to 60% by weight.

7. A process for the preparation of a phytosanitary composition adapted to be progressively disintegratable by contact with water, which process comprises dry-mixing at least one phytosanitarily active material with at least one non-hydrophilic filler, wherein a solid water-insoluble disintegrating agent is added during mixing, and the mixture subsequently compressed into single doses under a pressure of from 50 to 1,000 bars.

8. A process as claimed in claim 7 wherein at least one surfactant of the type normally used in the production of wettable powders is mixed together with said phytosanitarily active material and said non-hydrophilic filler.

9. A process as claimed in claim 7 or 8, wherein the disintegrating to 600 bars.

10. A process as claimed in claim 7, wherein the dry-mixing step com-prises two stages, wherein in a first stage the phytosanitarily active mater-ial, in the presence of any other additives and fillers is comminuted, and in a second stage the mixture resulting from the first stage is mixed with starch in the absence of any grinding.

11. A process as claimed in claim 8, wherein the dry-mixing step com-prises two stages, wherein in a first stage the phytosanitarily active mater-ial, in the presence of any other additives, fillers, and surfactants used is comminuted, and in a second stage the mixture resulting from the first stage is mixed with starch in the absence of any grinding.

12. A process as claimed in claim 10 or 11 wherein the comminution is achieved by grinding or micronising.