DE1927777A1 - Pyrethroid insecticides - Google Patents

Description

J

BERUH 33

S.C. Johnson & Son, Inc., Racine, Y / isconsin, Y.St.A.

Pyrethroid insecticides

The present invention relates to pyrethroid insecticidal agents. In particular, it specifies an insecticide which contains an insecticidally effective amount of at least one pyrethroid and at least one sorbitol ester of a saturated fatty acid.

Pyrethroids "represent a well-known class of insecticides which are extremely useful in fighting flies, mosquitoes, cockroaches, ants, silverfish and others annoying insects. They are esters of Ohrysanthemum acids. A particularly useful member of the pyrethroid class is the mixture of insecticidally active substances called pyrethrum known compounds, which can be obtained by extraction from pyrethrum flowers. The pyrethrum extract contains a number of pyrethrins, including pyrethrins I and II and cinerins I and II. A typical pyrethrum extract contains about $ 20 active pyrethroids, the rest consists of the extraction solvent. -Synthetic members of the pyrethroid class

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include allethrin, cyclethrin,
Dimethrin.

The pyrethroids are insecticides nützliehe ^ when used as r ":: -"^■:; those are used in suitable carrier formulations. : - The most commonly used synergist is piperonyl butoxide; although other synergists such as safrole, isosafrole and various derivatives thereof have been suggested. '■

The pyrethroids, particularly in Synergisierung, ■ - 'extremely active insecticides. This high level of activity, however, only extends over a relatively short period of time when the pyrethroids are exposed to air, light or other conditions determined by the environment * Depending on the particular environment in which the insecticide is used, the original activity actually takes place Senses completely lost within a very short period of time, which only under very unusual circumstances ^; more than six days is enough. With normal use ^:. ' these factors generally result in the total wiping out of the insecticidal activity of the '* "· -" - "pyrethroid within a period of less than ^: three days. This rapid loss of activity has severely limited the usefulness of the pyrethroids} for example, they are" not as Rüekstandsprühmi'ttel (i.Orig .: residual sprays) has been used in a satisfactory manner. The reason is that effective return 'stand-surface spray relatively high' kbhzen- """must be trated. Hinsichtlich.des" fast "Äkt'ivitatsverlustes can not justify the high cost concentrated to Äerstellung pyrethroid surface Spruniaittei will be. "'"' ^: '" ¹ " ■ *

The present invention proposes a pyreihroid insecticide before, over one to more than six weeks or even longer extended useful life. As a result, will by means of the areas to which pyrethroids "applied can be greatly expanded; the means are especially

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more than

Furthermore, they are unexpectedly extremely stable compared to loss of fructivity in the case of lending. The long-lasting Stability of these insecticides can be achieved both by chemical means can also be demonstrated by "biological testing techniques."

The pyrethroid that can be used is one of those previously described natural or synthetic materials. Pyrethrum extract is special because of its commercial availability suitable.

It has been found that the nature of the sorbitol ester used is crucial in terms of achieving long-term activity * The esters that can be used are the mono-, Di- and tri-esters of sorbitol and a saturated fat » acid. The term "sorbitol" used here is intended to be generic and includes sorbitol as such and condensed sorbitols such as sorbitan and sorbides. Of the The acid part of the ester comes from a saturated fatty acid, i.e., a saturated aliphatic hydrocarbon monocarboxylic acid of about 12 to 22 carbon atoms such as lauric acid, palmitic acid and stearic acid, the higher acids with 16 or more carbon atoms are preferred.

The ester can be in the form of a relatively pure compound or used as a mixture of several compounds » The mixtures can, for example, be a mixture of mono- »! Di- and (priests of the same acid, mixtures of esters of different boiled) Acids ^ mixtures of esters of sorbitol alone and condensed sorbitoie, or any combination of be these. In general, it is preferred that the ester is a solid or a highly viscous liquid, a gel or a Paste is. It is also preferred that the ratio of Acid to sorbitol with the composition of a sorbitol monoester comes close to being commercially available, Satisfactory means of use are the sorbitan

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laurat, which is sold under the trade name Span 20 « the sorbitan palmitate, which under the Haiadelsnaraen Span 40 sorbitan stearate, which is sold under the trade name Span 60 and 65 is sold. The preferred ester herein is sorbitan stearate. In certain embodiments of the In the invention it is preferred to modify the ester by a small controlled degree of ethoxylation. An ethoxylation to the extent of about 1 to 5, and preferably 2 to 3.5 moles of ethylene oxide per mole of ester is suitable, however a significantly greater degree of ethoxylation reduces the effectiveness of the ester in "extending the activity of. Pyrethroids to a considerable extent.

In addition to the pyrethroid and the sorbitol ether, the insecticide can this invention contain additional ingredients? which serve either a functional or an aesthetic room 1, for example perfumes, solvents, emulsifiers, antioxidants, ultraviolet absorbers, emulsifiers, corrosion inhibitors, Disinfectants, synergists, additional insecticides, etc. The main additional ingredient, which may be present is a synergist for the pyrethroid. While the pyrethroids as such are useful insecticides their activity will be greatly increased by the use of a synergist, and the use of a lower one Toxicity threshold is allowed. The most preferred The synergist is piperonyl butoxide, although other materials such as safrole, isosfrole, and various derivatives thereof, too have been used.

The compositions can be compiled in a number of ways to permit convenient use by the consumer. For example, they can preferably be manufactured as pressurized media in which the material in the can in the form of an oil-in-water emulsion, a water-in-oil emulsion or a solution is available. Such pressurized media can be made to be space sprays or surface sprays; the latter are because of the remaining activity that the novel com-

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show combinations of the invention, particularly suitable. The * suppressing can be done with one of the used in technology Propellants are made, including liquefiable hydrocarbons such as propane, butane and isobutane} liquefiable fluorinated Alkanes such as dichlorodifluoromethane, difluoroethane and tetrafluoroethane; and compressible inert gases such as nitric oxide, carbon dioxide, nitrogen, etc. It turned out to be special proven desirable to use the agents as water-in-oil emulsions made with hydrocarbon propellants, fluorinated alkane blowing agents or mixtures thereof are under pressure. The pressurized water-in-oil masses are particularly useful as residue surface sprays or porous surface agents are advantageous as the agents regulate the loss of active material Allow penetration of the porous surface.

Pressurized solution compositions are prepared by dissolving the pyrethroid and the selected sorbitol in a suitable solvent such as naphtha or mineral spirits _s and sets one of the above-mentioned propellant under pressure. The use of small amounts of alcohol, such as isopropanol, is desirable to improve the solubility of the sorbitol ester. Oil-in-water compositions are made by emulsifying the pyrethroid and other hydrophobic constituents in water and putting them under pressure with one of the listed propellants.

The compositions can also be put together for use in hand spray cans, pump spray cans, lever cans and the like will. They can be painted on the surface to be protected or be wiped up. These non-pressurized masses can be in the form of water-in-oil emulsions, Oil-in-water emulsions or solutions are present. They are made similar to the pressurized media, except that the propellant is omitted. In every lall they combine the quick, resounding effectiveness the pyrethroids with a long-lasting one sought after

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Activity not normally associated with pyrethroid toxins is obtained.

It has been found that the greatest possible residual activity is obtained when the weight ratio of the sorbitol ester of a saturated fatty acid to the non-volatile insecticidal residue of the agent is kept within a particular range. The sorbitol ester is as defined above. The "nonvolatile insecticidal residue" of the agent is the active residue remaining after the insecticide is applied and any components that are sufficiently volatile, such as solvents, propellants, diluents, etc., have escaped. Such residue typically includes the pyrethroid insecticide, any synergist present, and any non-volatile solvents such as the solvent present in the pyrethrum extract. The exact range of proportions which can be used will vary somewhat depending on the particular nature of the active insecticide, sorbitol ester, and other ingredients in the composition. However, the desired range for any particular agent is readily determined by the simple procedure of preparing a series of plague agents with varying amounts of sorbitol esters and determining the level of residual activity produced by each. The preferred range for the ester to nonvolatiles ratio herein is from about 0.1: 1 to 4.0: 1 when the preferred pyrethrin is employed. Slightly higher ratios may be appropriate when other pyrethroids are used and when synergists are not present. The range from 0.2 j 1 to 3.0 ϊ 1 is particularly preferred. If the ratio drops to a value well below the particular range, the pause in activity falls off quickly. A sharp decrease in activity is also observed at significantly higher ratios.

generally the means are made so _s & ai? one

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Insecticidally active amount from about 0.05% to 6% by weight Pyrethroid is given in the agent applied. That "Applied Agent" is that part of the mass which is applied to the Carrier or the insect is applied. Thus, in the case of the pressurized masses, the agent applied contains not the propellant, which evaporates essentially immediately upon release from the container. The applied The agent also preferably contains an effective amount of one of the aforementioned pyrethroid synergists. In general the synergist is in an amount of at least about 0.3 parts by weight, i.e. 1 part by weight per part by weight of pyrethroid available. It is usually not necessary to go beyond 10 parts of synergist per part of pyrethroid.

The practice of the present invention can be seen from the following illustrative examples. The following biological test method is used in the examples to demonstrate residual activity. The agent to be tested is applied to four corresponding glass surfaces in an amount of 2 ml each

0.09 m surface sprayed or pipetted on. the Plates are then air dried in a horizontal position in a control chamber that has a constant flow of air and has interior lighting. When the surfaces are dry, they are stored vertically on open racks under interior lighting. After the first 24 Hours and then weekly exposed to the insects until activity is no longer observed. the Test insects are 25 common house flies (musca domestica), which are 60 minutes over each of the corresponding Plates are kept in the cage. The number of flies struck is recorded after 15, 30 and 60 minutes. All Flies are then removed from the test areas and placed in cages where they can receive food and water. A final count of the flies killed is taken at the end of the 24 hours following removal from the test areas.

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men. To complete the test, the EinselergeTmisse are averaged. The persistence of insecticidal activity is reported as (i) the number of weeks during which the
Agent leads to at least a 90 follow kill after each period, and (ii) expressed as the number of weeks during which the agent has at least 50 fi effect (kill)
after 24 hours.

example 1

Two pressurized insecticide masses made from water-in-oil emulsion (oil-out emulsion) are prepared to allow the following Ingredients in the amounts given in parts by weight are:

AWAY

$ 20 pyrethrin extract 1, '; 1.25

technical grade piperonyl butoxide 1.25 1.25

Fragrance 0.05 0.05

Sorbitan monooleate ¹ '0.50 0.50

2)
ethoxylated sorbitan monostearate '2.50 - -

Water 55.45 57.95

n-butane 6.00 6.00

Isobutane 8.00 8.00

Dichlorodifluoromethane 25.00 25 »00

1) is sold under the trade name Span 80

2) contains 3 moles of ethylene oxide per mole of sorbitan monostearate and is sold under the trade name
Atlas 9096-C sold

Thus, A contains a saturated sorbitan ester selected according to the invention and B does not. In A the ratio is
Esters to non-volatile substances 1.7: 1. If the masses described on residual activity due to the previously described
Test method tested, A is found to have a 100% effect in 15 minutes and a 100% kill in 24 hours, even at the end of an 8 week test period. to
at this point the test was canceled even when

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the agent has not yet shown any sign of decreased activity. In contrast, mass B quickly lost its activity. At the end of two weeks there was only 31% effect after 15 minutes and only 7% kill after 24 hours.

Example 2

Two pressurized solvent-insecticide masses to be compared are prepared with the following ingredients in the amounts indicated in parts by weight included are:

A _B

20 fo pyrethrin extract 1.25 1.25

technical grade piperonyl butoxide 1.25 1.25

1)

Sorbitan monostearate '1.50 -

Isopropanol 10.00 10.00

solvent 140 26.00 27.50

Trichlorofluoromethane 25.00 25.00

Dichlorodifluoromethane 35.00 35, OCf

1) is sold under the trade name Span 60

Thus, A contains a saturated sorbitan ester selected according to the invention, whereas B does not contain it. When the two compounds are tested ivitäts test according to the previously described Restakt, it is found that after one hour's exposure to A io effect and shows more than 90 50 $ sodium killing after 24 hours at the end of 6 weeks of testing. In contrast, B. 'gives only one at the end of a week. 1 $ effect after an hour and only a 2 $ kill after 24 hours.

Example 3

The aim of this comparative evaluation is to show that the achievement of the long-lasting residual activity is specific for combining pyrethroid insecticides with the one here sorbitol esters previously described. In these comparisons

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the following base material is used:

Components parts by weight

$ 20> pyrethrin extract 0.5

technical grade piperonyl butoxide, 0.5

Sorbitol oil ester 0.6

ethoxylated sorbitan monopalmitate 0.1

Water 98.3

1) contains 20 moles of ethylene oxide per mole of sorbitan monopalmitate and is sold under the trade name Tween.

The sorbitol esters used in each of the cases are A-J the following:

A - sorbitan monostearate, sold under the trade name Span 60.

B - sorbitan tristearate, sold under the trade name Span 65.

C - ethoxylated sorbitan monostearate containing about 4 moles of ethylene oxide Contains sorbitan monostearate per mole sold under the trade name Tween 61.

D - sorbitan monopalmitate, sold under the trade name Span 40.

E - sorbitan monolaurate, sold under the trade name Chip 20.

F - ethoxylated sorbitan monolaurate, which contains about 20 moles of ethylene oxide per mole of sorbitan monolaurate.

G - ethoxylated sorbitan monostearate, which contains about 20 moles of ethylene oxide per mole of sorbitan monostearate and below the trade name Tween 60 is sold.

H - ethoxylated sorbitan monooleate, which contains about 20 moles of ethylene oxide Contains sorbitan monooleate per mole and is sold under the trade name Tween 80.

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I - ethoxylated sorbitan monopalmitate, which contains about 20 mol Contains ethylene oxide per mole of sorbitan monooleate and below the trade name Tween 40 is sold.

J - Sorbitan monooleate sold under the trade name Span

Thus, A-E represent an implementation of the present invention, with A, C and D being preferred embodiments. F-J are agents that are outside the invention because the sorbitol esters used have too high a degree of ethoxylation or rather they are esters of an unsaturated instead of a saturated fatty acid.

Each of the agents A-J is subjected to the residual activity test described above checked and the results observed. For each means the percentage will be within 15 minutes after two weeks of chipped flies, the number of weeks, for which the remedy is at least 90 pounds within one hour and at least 50? killing within 24 hours there, reproduced. A tabular summary of these results follows:

° / o effect
in 15 Wed
grooves after
Mean 2 weeks 100 SOfi effect
duration
(Weeks) io killed
in 24 hours
the after
2 weeks 50 $
Kill
duration
(Weeks) A. 97 8th 100 5 B. 100 4th 80. 2 C. 100 8th 100 7th D. 100 8th 100 7th E. 6th 2 100 2 F. 13th 1 38 1 G 4th 1 37 1 H 36 1 13th 1 I. 0 1 57 2 J 1 1 1

From the table above it can easily be seen that A-E embodying the present invention

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result in a greatly increased residual activity and the preferred agents A, C and D are particularly good.

Example 4

This example illustrates a number of unpressurized insecticide masses where different ratios from sorbitol esters to non-volatile substances. In each of the cases A-K the following matrix becomes used:

component Parts by weight Isopropanol 15.00 Sorbitan monostearate ' varying 20 1 ° pyrethrin extract 0.50 technical grade piperonyl butoxide 0.50 n-heptane rest

1) is sold under the trade name Span 60

The amounts and the resulting ratio of sorbitol esters to non-volatile substances is as follows:

Means ABCDEFGHIJK

Each of the above agents are tested with the residual activity test previously described. For each agent, the percentage is within 15 minutes, 30 minutes and 60 minutes

Wt% relationship 0.00 0.06 0.1 0.12 • 0.2 0.3 0.5 0.6 1.0 0.9 1.5 1.2 2.0. 1.8 .3.0! 3.0 5.0! 4.5 7.5 ι 6.0 10.0: ί 1 : 1 ί 1 : 1 ί 1 1 1 1 1 1

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battered flies and the percentage of within Flies killed 24 hours after two weeks, as well as the total number of weeks for which each agent was recorded at least a 90 $ effect within an hour and showed at least $ 50 kill within 24 hours. The results of these tests are as follows:

Two week results effect 60 min. ■ "' io destruction Duration (weeks) Mortification middle . 30 min. 0 24 hours effect $ 50 15 minutes 0 97 I 0 $ 90 <1 A. 0 96 96 I 78 3 B. 89 96 100 ; 80 3 3 C. 92 100 100 98 4th 3 D. 98 100 100 98 4 ' 4th E. 99 100 99 ; 98 4th 4th F. 100 99 97 96 4th 4th G 98 92 75 i 77 4th 4th H 77 60 77 S ¹² 4th 1 I. 14th 45 77 9 1 1 J 6th 46 6th 1 <1 K 14th <1

As shown in the table above, the masses give a ratio of sorbitol esters to non-volatile Substances which fall in the range from 0.1 to 4.0 have the greatest possible residual activity and those which have a ratio between 0.5 and 3.0 are particularly good.

Example 5

This example illustrates the use of several Sorbitol esters in unpressurized insecticide masses falling within the scope of the invention. In each of these The following matrix is used for examples:

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ι eta * ··· ·

-14 component parts by weight

Isopropanol 15.0 Sorbitol esters 0.6 $ 20 pyrethrin extract 0.5 technical grade piperonyl butoxide 0.5 Mineral spirits 83.4

In mean A, the sorbitol ester and white spirit are omitted has been raised to 84.0 parts. Thus, A represents a control mass. In the remaining examples, the the following sorbitol esters are used:

B - sorbitan monostearate, sold under the trade name Span 60.

C - sorbitan monopalm sold under the trade name Chip 40.

D - ethoxylated sorbitan monostearate, which contains about 3 moles of ethylene oxide per mole of sorbitan monostearate and below the Trade name Atlas 9096-C is sold.

E - ethoxylated sorbitan monostearate, which contains about 2 moles of ethylene oxide per mole of sorbitan monostearate and below the Trade name Emery 15096 is sold.

]? - ethoxylated sorbitan monopalmicity, which is about 4 mol Contains ethylene oxide per mole of sorbitan monopalmicity and below is sold under the trade name Emery 15099.

Each mass is tested with the previously described residual activity sowing test. The number of weeks for which each resource is at least 90 # effect within an hour and 50 $ kill shows within 24 hours are listed in the following table:

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Persistence of activity (weeks) mean ₉₀ ^ _effect 5o # kill

A <1 xr 1

B 3 3

C 3 3

D 3 3

E 54

P 2.3

Example 6

Two non-pressurized neopynamine insecticide masses are made as follows:

component

Isopropanol Sorbitan Monostearate 'Neopynamin technical piperonyl butoxide mineral spirits

1) is sold under the trade name Span 60.

After two weeks, the mass of A shows a 100% effect within 15 minutes and 100% destruction within 24 hours. After the same period of time, the mass of B shows an effect of 0 # and kill of 0 #. In example A the high activity remains after 5 weeks and gives a 96 # effect within one hour and one 63 ^ ige destruction within 24 hours.

Example 7

This example illustrates the practice of the invention using piperonal bis [2- (2-butoxyethoxy) ethyl] acetal, which is sold under the trade name Tropitol, as

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A. B. 15.0 96 15.0 0.6 - 0.12 0.12 0.5 0.5 rest Best

$ 15.0> 15.0% 0.6 - 0.5 0.5 0.5 0.5 Rest - rest

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Pyrethrin synergist. The funds are made as follows!

Component A JL

Isopropanol

Sorbitan monostearate '

Synergist

$ 20> Pyrethrin Extract

Mineral spirits

1) is sold under the trade name Span 60.

After two weeks, the mass of A shows an effect of 100 # within one hour and 99 $ kill within 24 hours. After the same period of time, the mass of B shows an effect of 0 io and kill of 0 $>.

It is to be understood that the foregoing examples are illustrative of embodiments of the present invention and that substantially similar results are obtained when various other specific materials are used that fall under the general explanations.

Example 8

This example illustrates compositions which do not contain a synergist for the pyrethroid insecticide. The crowds are manufactured as follows

Ingredient weight percent

Isopropanol 15.0

Sorbitan monostearate varying 20 # pyrethrin extract 3.0

n-heptane rest

1) is sold under the trade name Spaa 60. The amounts of sorbitan monostearate used are as follows;

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middle ψο sorbitol esters relationship A. 0 B. 0.12 0.2 C. 0.6 1 D. 3.0 5

After a week, the activity is like each of the means follows:

middle % Effect after 1 hour fo mortification A. CVJ O B. 77 57, C. 89 47 D. 77 17th

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Patent claims;

Claims (10)

-18- J 531 claims 1. Insecticide, consisting of an insecticidally effective amount at least one pyrethroid and at least one sorbitol ester of a saturated fatty acid. 2. Insecticide according to claim 1, wherein the ratio of the ester to the non-volatile part of the insecticide within the Range from about 0.1: 1 to 4: 1. 3. Insecticide according to claim 1 or 2, wherein an effective amount of a synergist for said pyrethroid contains is. The insecticide of Claim 3 wherein the synergist is piperonyl butoxide and is contained in an amount of about 0.3 Ms 10 parts by weight per part by weight of pyrethroid, 5. An insecticide according to any preceding claim, wherein the saturated fatty acid has at least 16 carbon atoms contains. 6. Insecticide according to any one of the preceding claims, wherein the saturated fatty acid is present in an amount approaching the monoester of said sorbitol. 7. Insecticide according to any one of the preceding claims, wherein the saturated fatty acid is stearic acid. 8. Insecticide according to any one of the preceding claims, wherein the pyrethroid contains pyrethrih. 9. Insecticide according to one of the preceding claims, wherein the ratio of the ester to the non-volatile portion of the agent is within the range of about 0.2: 1 to 3: 1 lies. 10. Insecticide according to one of the preceding claims, wherein the sorbitol ester is an ethoxylated ester, the degree of ethoxylation being 1 to 5 moles of ethylene oxide per mole of ester . Dr, Pa / Wr 909849/1507