US 2345891 A
Description (OCR text may contain errors)
Patented 4, 1944 2,345,891 SYNERGISTS 'ro AEROSOL INSECTICIDES William N. Sullivan,
Washington, D. 0., and Lyle D. Goodhue, Berwyn, Md., asslgnors to Claude R. Wlckard, as Secretary United States of America,
in oillce of Agriculture 01' the and to his successors No Drawing. Application September 30, 1941,
5 Claims. (01. low-22) (Granted under the act of March 3, 183, as amended April 30, 1928; 370 0. G. 757) This application is made under the act of March 3, 1833, as amended by the act of April 30, 1928, and the invention herein described and claimed, if patented, may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment to us of any royalty thereon.
Our invention relates to materials which will increase the effectiveness of insecticides in aero-' sol form.
Certain agents which may or may not be toxic in themselves when added to aerosol insecticides greatly increase the rate of mortality. The increased toxicity obtained by the combination of such materials is often referred to as "synergism and the added material a synergist., Therefore, in these terms, the general object of our invention is the provision or materials suitable as synergists for aerosol insecticides. 7
Another object of our invention is the proviof fatty acids and ethylene or propylene glycol, of glycerine or sorbitol, to be especially suitable as well as fatty acids in combination with amines such as methanolamine, sulfonated aryl and alkyl radicals alone or combined with an amine.
There are many processes which can be used to apply these materials in the form of aerosols, such as spraying into the atmosphere, vaporization, by chemical reaction, by spraying on a heated surface, and so forth. Although this invention is not limited to any particular method of application, our preferred method of application comprises dissolving the synergist in the insecticide, if the insecticide is a liquid, or dissolving it in some solvent common to both if a solid, and
. praying the solution on a heated surface, wheresion of agents which will notonly increase the I insecticidal action of materials known to possess some toxicity, but, which will also impart insecticidal properties to materials which are known to be non-toxic or to have a very low toxicity.
A further object of our invention is the provision of such agents acting as synergists, which can be applied by dispersion simultaneously with and by the same methods used for the preparation of aerosol insecticides.
We have found that materials suitable for the purposes of-this invention belong most frequently to the class of chemical compounds which are surface active in non-aqueous solvents or which act as detergents in non-aqueous solvents. These compounds, in general, contain polar groupings such as the hydroxyl, the carboxyl, the amine, the ammonium, or the sulionic acid, alone, in multiple, or in combination, which is attached to some long chain aliphatic radical, or, in some cases; an aromatic radical.
Substances-acting as detergents or surface active agents in non-aqueous media can be easily applied by the usual methods of aerosol production, but this invention is not limited to these substances because different methods of. aerosol production can be used with diiferent types of synergists. Inthis class of chemical compounds we have found the fatty acids, the mono esters ergists in accordance with -zene per 1000 cu. it. gave only a 2% by an aerosol is formed composed of both the synergist and the insecticide.
A synergist to an insecticide in aerosol form is not necessarily also a synergist to an insecticide in spray form, even of the same compound. Ac-' tual tests have disclosed that an agent which possesses little or no effect as a synergist to an insecticidal spray may be extremely effectiveas a. synergist to an insecticidal aerosol. The reason for this is not apparent, but it would seem that the mere wetting of the insect cannot explain the action.
The following results were obtained using syn. this invention. These results were obtained on the basis of preliminary tests first carried out in a small chamber of 7 cu. ft. and then on a larger scale in a 216 cu. ft. chamber. In each test from 500 to 600 flies were used. Six-tenths of a pound oi o-dichlorobenkill. However, when mixed with 0.16 lb. of oleic acid as a synergist, a kill was obtained. This same quantity of oleic acid, when used alone under the same conditions gave only a 1% kill. Laurie acid when used alone in the same amount, namely, 0.16 lb. per 1000 cu. i't., gave only a 1% kill, but when used as a synergist with 0.6 lb. of o-dichlorobenzene per 1000 cu. it. a kill was obtained.
The same synergists were testedv at other concentrations and it was found that little is gained by adding more than 10%.
The i'ollowing is a list of substances which were tested as synerl ats at a concentration 0! plus oleic acid, ethyl 0.06 lb. in 0.6 lb. of o-dichlorobenzene per 1000 cu. it. against the housefly, the percentage of kill in each case being indicated in the right hand column:
. Per cent kill Spermaceti 37 Diglycol laurate 43 Sulfonated naphthalene 60 Salicylic acid 91 Propylene glycol oleate 28' Myristic acid 49 Propylene glycol laurate '74 Sorbitol laurate 59 Monoglycol laurate 56 Triethanolamine oleate 56 Lauryl sulfate 70 chloroethane plus lauric acid, and o-dichlorobenzene plus lauric acid. In all cases where oleic acid was efiective, lauric acid was also found to be effective and vice versa. The kill without a synergist was always less than 100% and usually less than 50%.
In a 1100 cu. ft. room, naturally infested with cockroaches, more than 5000 were killed in 18 hours and none were found living, using 1 /2 lbs.-
of o-dichlorobenzene with 3% lauric acid and p 2% oleic acid. Excellent results were also obtafned in a 3200 cu. ft. room.
Tests were also conducted against the carpet beetle larva, the confused flour beetles and crickets. The halogenated esters in combination with any oneof the synergists mentioned above is extremely toxic to the confused flour beetle and produces a high mortality to the carpet beetle larva.
Among compounds tested against the housefly in the form of aerosols, in combination with synergists of the type mentioned above are, 3-chloroacenaphthene, z-chlorofluorene, 3-chlorodibenzofuran, chlorinated diphenyls, halogenated naphthalenes, halogenated esters, halogenated ketones, carbazole, thiocresol and halogenated phenols. The synergist was'shown to be responsible in each case for an increase in toxiclty.
Having thus described our invention, we claim:
1. An insecticide in aerosol i'orm comprising ortho-dichlorobenzene and lauric acid.
2. An insecticide in aerosol form comprising a solution containing essentially 99.9 to parts by weight of ortho-dichlorobenzene and 0.1 to 10 parts by weight of lauric acid.
3. An insecticide in aerosol form comprising ortho-dichlorobenzene and oleicacid.
4. An insecticide in aerosol form: comprising a solution containing essentially 99.9 to 90 parts by weight of ortho-dichlorobenzene and 0.1 to 10 parts by weight of oleic acid.
5. An insecticide in aerosol form comprising ortho-dichlorobenzene and myristic acid.
WILLIAM N. SULLIVAN. LYLE D. GOODHUE.