AU627382B2 - Pesticidal composition - Google Patents

Description

3!1- 627382 COMMONWEALTH OF AUSTRALIA Patents Act 1952 Name of Applicant Address of Applicant Actual Inventor(s) Address for Service 1 E t t<A- SoenA-lt4 J^^clcc0r\ T^r c MORRI -MORRISON; DEAN-BRUGE-

MORRI-SON--ADAM-

4I 1 ens v-a-l-e R-o-a-d-, i caensvee===-- Queen s-l-and--4-2-1-0, Au-tra-1ia, MORRISON; BRUCE JON MORRISON; DEAN BRUCE MORRISON; ADAM GRANT ADAMS COMPANY Patent Trade Mark Attorneys Level 9 NATIONAL MUTUAL CENTRE 144 Edward Street Brisbane, Queensland, 4000

AUSTRALIA.

COMPLETE SPECIFICATION FOR THE INVENTION ENTITLED: PESTICIDAL COMPOSITON The following statement is a full description of the invention including the best method of performing it known to the applicant.

i L i THIS INVENTION relates to pesticidal compositions. In particular, it is directed to compositions containing both fumigant and residual pesticidal ingredients which function first to exterminate quickly any pests immediately present but then leave a residual protection against pests in the area or on the surfaces to which the composition has been applied.

There are many domestic and commercial applications wherein areas and surfaces must be protected against infestation by insects and other pests. For example, household cupboards, wardrobes, pantries and the like must be protected against invasion by ants, cockroaches and other pests. Similarly, in commercial'premises and establishments such as restaurants, cafes and the like it is essential, and often mandatory under government health regulations, that areas used for the storage of food and/or the preparation and serving of meals be kept pest free.

Of particular concern are German cockroaches. These pests have a marked resistance to most of the known pesticides, including the synthetic pyrethroids.

Conventional treatments only remove this species of cockroach for a period between several days and three months. Further, conventional treatments do not affect any eggs which may have been deposited by the female cockroach. Accordingly, the eggs hatch and reinfestation occurs.

In the past, organo phosphates were the preferred choice for the extermination and control of these pests, although they have been virtually superceded today by synthetic pyrethroids and carbamates. However, two well-knowr organo phosphates still in use are dichlorvos and chlorpyrifos. Dichlorvos is commonly 2 j used as a fumigant and thus used when it is necessary to kill pests already present in an affected area.

Chlorpyrifos is a residual and is, therefore, utilised to keep an already cleared area free from pests.

Nevertheless, individually, neither dichlorvos nor chlorpyrifos are considered to be very effective.

It is also known to provide a pesticidal composition which is a combination of fumigant and residual ingredients. In fact, dichlorvos has been used as an additive to a residual-type pesticide. Although when used as such an additive, dichlorvos does reduce the r "knockdown" time required to eliminate existing pests, it does not increase the effective life of the residual ingredient to which it has been added. For this reason, dichlorvos is rarely used now in the pest control industry as the extra expense incurred in its inclusion in the composition to reduce the immediate numbers of pests present is not outweighed by any lasting advantage of the residual component. V Further, a disadvantage of the residual chlorpyrifos is that it is readily removed by cleaning of treated surfaces, such cleaning, of course, being a regular occurrence in food storage, preparation and serving areas.

Yet another disadvantage of prior pesticidal compositions, whether they contain residual ingredients or not, is that a pest usually must remain in a treated area for a sufficient period for the pesticidal composition to be effective. If the pest remains for that sufficient period, then often enough ccintact with the active ingredient has been made to eradicate the pest, even if the pest first leaves the treated area before dying. On the other hand, if the pest leaves the treated area before sufficient contact is made with the active ingredient, then the pest may again return to the area as it is unaware that that environment is hostile to it.

It is a general object of the present invention to overcome, or at least ameliorate, one or more of the above problems and to provide a pesticidal composition containing both fumigant and residual ingredients which not only quickly exterminates existing pests but which also leaves a residual pesticidal protection which is not readily removed by conventional cleaning processes.

S The present Liventors have discovered that the general object can be achieved by first mixing fumigant and residual concentrates together and then subjecting the mixture to either mechanical agitation or electromagnetic radiation.

Thus according to a first aspect of the present invention, there is provided a pesticidal composition, said composition comprising: Itt, a) at least one fumigant; and b) at least one residual; f t wherein said at least one fumigant and said at least one residual have been added together in a Sconcentrated form and then subjected to either mechanical agitation or electromagnetic radiation.

The inventors have also discovered that the life of the said at least one residual can be further extended by the addition of a high molecular weight polymer.

11 In addition to the active ingredients, the compositions of the present invention may optionally include other, non-active ingredients, such as the usual diluents and carriers.

Another optional feature of the compositions of the present invention is the addition of a pest attractant, for example, a sweetening agent.

According to a second aspect of the present invention, there is provided a process for the preparation of a pesticidal composition, said processing comprising: 1) combining, in any order, at least one fumigant and at least one residual, each in a concentrated form; 2) subjecting the thus obtained mixture to either mechanical agitation or electromagnetic radiation; whereupon the resultant composition may have added, optionally, any required diluent, carrier or other ingredient.

Preferably, both the fumigant and residual are selected from the group of compounds known as organo phosphates.

More preferably, the fumigant is dichlorvos and the residual is chlorpyrifos.

Preferably, the composition also includes a high molecular weight polymer. More preferably, this high molecular weight polymer is polyvinyl alcohol (PVA).

Optionally, the composition may include sugar as the sweetening agent to attract pests to the treated area.

Preferably, the composition is subjected to electromagnetic radiation after adding the ingredients.

More preferably, microwave radiation is employed.

Examples of the composition of the present invention will now be described.

EXAMPLE 1 Commercially available dichlorvos (75 ml) and chlorpyrifos (75 ml) concentrates are mixed together and then subjected to high microwave radiation for approximately 15 seconds. The mixture is diluted to litres with water.

EXAMPLE 2 Polyvinyl alcohol (50 ml) was added to the composition of Example 1.

EXAMPLE 3 Commercially available dichlorvos (180 ml) and no chlorpyrifos (120 ml) concentrates are mixed together and added slowly to polyvinyl alcohol (200 ml) in water S(2 L) with agitation and then further diluted with water (8 L).

The quantity of polyvinyl alcohol added can be altered to change the viscosity of the resultant composition.

EXAMPLE 4 Commercially available dichlorvas (120 ml) and chlorpyrifos (180 ml) concentrates are mixed together and added slowly to polyvinyl alcohol (200 ml) in water (2 L) with agitation and then further diluted with water Sugar (400 g) dissolved in hot water is added as A sweetening agent which attracts pests to the area to be treated.

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r In use, the compositions are sprayed upon the surface to be protected whereupon any pest is quickly exterminated.

In the absence of PVA, residual protection can last for at least 12 months; in its presence, the residual efficacy can be approximately two years.

The alcoholic composition of Example 3 can be conveniently applied to light covers whereupon the heat emitted by lights when in operation release the dichlorvos thus killing mosquitoes and other flying insects which are attracted to the lights.

Major advantages of the present invention include the composition exhibits a synergistic effect on the individual properties of the respective components; significantly less quantities of individual ingredients are required to achieve this synergistic effect; and the presence of the composition in the treated area appears to prevent female pests from depositing eggs thereon thus significantly reducing the likelihood of re-infestation.

In fact, when used in the compositions of the present invention, 50% less than the individual recommended rates can be used. As an example, in isolation, the residual chlorpyrifos takes seven days to reduce cockroach infestations and remains efficacious for a 25 maximum of three months. However, when chlorpyrifos is used in the present invention, all cockroaches are killed within a few hours and the residual action ran remain effective indoors for up to two years. YIJr outdoor use, even with PVA added, this effectiveness is reduced because of UV breakdown of the composition but its efficacy still represents a marked improvement over the prior art.

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A further advantage is that the compositions provide a positive repelling effect. Due to the efficacious residual action of the present invention, pests such as cockroaches which take in air from underneath their bodies and thus have their lungs in close proximity to the treated surface, become immediately aware that the environment is hostile resulting in a retreat by the pest.

Although not wishing to be bound by theory, it is believed that the mixing together of the fumigant and residual concentrates and subjecting the mixture to mechanical agitation or electromagnetic radiation results in an extremely fine diminution of the residual.

Once the mixture has been applied and the solvent evaporates, ultra fine crystals of the residual remain in the surface irregularities of the area treated and these crystals are difficult to remove by conventional cleaning methods. This effect is enhanced in the presence of PVA whereby the fine crystals are impregnated in a thin film of PVA which further prevents the easy removal of the residual from the treated surface.

The present invention is thus expected to be effective for any combination of fumigant and residual whereby at 25 least the residual component can be diminuted to an ultra fine crystaline form.

By using the compositions of the present invention, effective and continual protection against insects such as cockroaches, mosquitoes, ants and midges can be achieved, although it will be appreciated that the above examples are given by way of exemplification of the invention only, and that changes may be madu to the details set out therein without departing from the scope 0orr *P 0

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i 11 of the invention as defined in the following claims.

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Claims (11)

1. 2. A pesticidal composition as defined in Claim 1, wherein said at least one fumigant is dichlorvos.
2. 3. A pesticidal composition as defined in Claim 1 or o., 15 Claim 2, wherein said at least one residual is chlorpyrifos.
3. 4. A pesticidal composition as defined in any one of C":laims 1 to 3 also comprising a high molecular weight polymer.
4. 5. A pesticidal composition as defined in Claim 4 wherein said high molecular weight polyaer is polyvinyl alcohol.
5. 6. A pesticidal composition as defined in any one of Claims 1 to 5 also comprising a sweetening agent.
6. 7. A pesticidal composition as defined in Claim 6 wherein said sweetening yent is sugar. 3. Apsiialcmoiin sdfndinCam1oQ 4 I S 1 lam2,weri si a lat n rsdulisi «.i pr i1> N a 44 *4 0 a I .41 a a
7. 8. A pesticidal. 4mposition as defined in any one of Claims 1 to 7 which has been subjected to microwave radiation.
8. 9. A process for the preparation of a pesticidal composition, said processing comprising: 1) combining, in any order, at least one fumigant and at least one residual, each in a concentrated form; and 2) subjecting the thus obtained mixture to either mechanical agitation or microwave radiation; wherein said at least one fumigant and said at least one residual are each selected from the group of compounds known as organo phosphates. 15 10. A process as defined in Claim 9, wherein said obtained mixture is subjected to microwave radiation.
9. 11. A process as defined in C4aim 9 or Claim wherein said pesticidal composition is as defined 20 in any one of Claims 2 to 7.
10. 12. A pesticidal composition as defined in Claim 1 substantially as hereindescribed with reference to the Examples. 11 4e 4444 4 a. 4 a., 444,',t O I Iu '4 1 Pr
11. 13. A process as def ined in Claim 9 substantially as hereindescribed with reference to the Examples. DATED this twenty ninth day of May 1992 MJA ScientifIcs International Pty Ltd by its Patent Attorneys GRANT ADAMS COMPANY CC C. CCC. C C C iC CC. C C C I C C CC C C C C C C 'C 'C C C C C C C