United States Patent 19 11, 3,867,526 Hennart et al. (45) Feb. 18, 1975 54 STABILIZED COMPOSITIONS Feb. 2, 1969 France .............................. 69.03313 CONTAINING A PHOSPHORIC ACID ESTER June 21, 1968 France............................ 68. 156O25 PESTICIDE AND AN ALCOHOLIC Dec. 18, 1969 Luxembourg.......................... 60.052 COMPOUND (75) Inventors: Claude Hennart, Aubervilliers, 52 U.S. Cl. ................................................ 424/219 Jean-Pierre Mandon, Paris; Georges I51) Int. Cl............................................... AOn 9/36 Martin, Saint Benoit; Bernard 58 Field of Search............................. 424/219, 222 Rabussier, Avanton, all of France 56 References Cited 73 Assignee: Ciba-Geigy AG, Basel, Switzerland UNITED STATES PATENTS 22 Filed: Sept. 20, 1972 3,130,120 4/1964 Schultz et al....................... 424/219 21 Appl. No.: 290,509 Primary Examiner-Sam Rosen Related U.S. Application Data Attorney, Agent, or Firm-Wenderoth, Lind & Ponack 63 Continuation-in-part of Ser. Nos. 833,665, June 16, 1969, Pat. No. 3,705,941, and Ser. No. 17,918, 57 ABSTRACT March 9, 1970, abandoned. Compositions containing a volatile pesticidal phos phoric ester, an alcoholic compound having at 20°C a 30 Foreign Application Priority Data vapor pressure between 0.01 and 30 TORR and a sta Mar. 12, 1969 France.............................. 69.06859 bilizing agent for the phosphoric acid ester are dis Mar. 12, 1969 France.............................. 69.06860 closed. Mar. 12, 1969 France.............................. 69.06861 Mar. 12, 1969 France.............................. 69.06862 12 Claims, No Drawings 3,867,526 2 STABILIZED COMPOSITIONS CONTAINING A carbon atoms in solid compositions based on 0-(2,2- PHOSPHORIC ACID ESTER PESTICIDE AND AN dichlorovinyl)-0,0-diemthyl phospate, or DDVP, from ALCOHOLIC COMPOUND which the volatile and insecticidal phosphoric ester can This application is a continuation-in-part of our co evaporate into the atmosphere. pending patent applications Ser. No. 833,665 filed on 5 Stabilizers such as, for example, epoxidized com June 16, 1969, now U.S. Pat. No. 3,705,941 and Ser. pounds or polyamines, have been recommended with No. 17,918 filed on Mar. 9, 1970, now abandoned. a view to protecting the phosphoric esters from hydro The present invention relates to hydrophobic compo lysis. However, these stabilizers are in general only sitions comprising phosphoric esters as active insecti slightly volatile and can thus be used only in small cidal materials. 10 quantities to avoid their accumulation on the wick; the Such compositions are more particularly useful in efficacy of these stabilizers is accordingly reduced. It permanent insecticidal apparatuses called wick evapo has been found that above a maximum limit of 3per rators, which slowly release insecticide vapors into the cent, the accumulation of these stabilizers on the evap atmosphere to combat noxious or undesirable insects orative surface generally gives rise to a rapid decrease such as flies, mosquitos, gnats, cockroaches, wasps, 15 in the rate of a evaporation. fleas, bugs, ants, mites etc. An apparently simple method of avoiding or substan It is known to evaporate insecticidal phosphoric es tially reducing hydrolysis of phosphoric esters consists ters dispersed, for example, in a solid solution in polyvi in using solutions of these esters in hydrocarbons; all nyl chloride. the same, the unsaturated hydrocarbons are unsuited, With this mode of insecticide release, the daily evap 20 on account of their high toxicity and disagreeable oration of the active substance is not constant; it de odour, to be used as the sole solvent. The saturated hy creases regularly as the usage is prolonged; as a result, drocarbons are not toxic, but possess much too weak the efficacy varies with time, and it becomes progres a solvent power so that their use in evaporator devices sively weaker, becoming zero well before the evapora would give too weak, a release of insecticide vapor to tion of the active substance contained in the solid solu 25 be efficacious, or would necessitate a reservoir and an tion is complete. evaporation surface of exaggerated dimensions. To avoid this disadvantage, it has been attempted to It has been found that completely hydrophobic solu increase the quantity of active substance introduced tions of phosphoric esters of sufficiently high concen into the polyvinyl chloride resin; the time of efficacy tration can be obtained by adding to the solution of can therefore be prolonged, but in return the rate of 30 such ester in a saturated hydrocarbon solvent a rela evaporation which is greatly increased above the re tively small amount of certain co-solvents (or stabiliz quired level during the first few days of use can reach ers) which are described in detail further below. The values which are no longer harmless, and can be very hydrophobic properties of such solutions are com toxic, to mammals, and particularly to human beings, pletely satisfactory, even in the case where the co when such use takes place in a closed room. 35 solvent is itself very hydrophilic. This decrease of the rate of evaporation of the active It is an object of the invention to provide liquid hy substance makes the use of the aforesaid compositions drophobic compositions which will satisfy the following uneconomic, as more than the phosphoric ester used is requirements: still present when the efficacy of the composition has 1. permitting their use in devices diffusing into the become practically nil. 40 atmosphere, permanently, insecticidal vapors, It is likewise known to use an evaporator apparatus without risk of premature decomposition, more in which a porous of fibrous material, such as an ag particularly of the active material; glomeration of organic and/or mineral fibres, or a per 2. permitting as complete evaporation as possible of meable ceramic, can be fed by a volatile liquid on one the active substance used; part of its surface while the liquid gradually evaporates 45 3. permitting a regular and constant evaporation and through the other part in contact with the atmosphere. therefore an insecticidal efficacy constant in time. When the volatile liquid is a phosphoric ester, then cer These objects are attained by the hydrophobic com tain of these esters, mainly those of greatest insecticidal positions provided by the invention. These composi efficacy, have the disadvantage of hydrolising rapidly if tions are characterized in that they comprise they are exposed to the ambient air over a large sur 50 a. at least one insecticidal volatile phosphoric ester as face. Such is the case if the esters are used in the pure defined infra, as active material; state in a wick evaporator apparatus; they take up the b. about to 80 percent of a compound carrying at humidity in the atmosphere very rapidly and are thus least one alcoholic hydroxy group per molecular, very rapidly hydrolysed; it has been found that in this and acting as solvent on (a) case the hydrolysis does not stop at the level of the 55 c. from about 0.1 to 20 percent of a stabilizing agent evaporation surface, but affects the contents of the res for said phosphoric ester, all percentages being ervoir to a large degree. based on the total weight of the composition and This disadvantage must be met by use of a corre d. optionally a saturated aliphatic hydrocarbon in spondingly increased amount of active substance, or, which case component (b) acts as co-solvent. without such increase, it leads to a greatly diminished 60 Compositions according to the invention can contain time of efficacy. In addition, the accumulation of de from about 1 up to 95 percent of active substance cal composition products on the evaporation surface dis culated on the weight of the composition. Preferably turbs the regularity of the evaporation. the proportion of active substance is between 3 and 25 Furthermore, the use of alcohols, in insecticidal com percent based on the weight of the composition. posititons based on phosphoric esters, as solvents or 65 When containing component (d), these compositions diluents for the esters is well known. It has been pro can contain up to 40 percent of co-solvent calculated posed, for example to use alcohols having at least 10 on the weight of the composition. Preferably, this por 3,867,526 3 4 portion is between 1 and 20 percent based on the As non limitative examples of esters corresponding to weight of the composition. Of course, a sufficient the general formula given, there can be noted the fol amount of component (d) should then be present in lowing phosphoric esters: order to guarantee, jointly with the co-solvent present 2,2-dichlorovinyl dimethyl phosphate in the above-given limits, a complete dissolution of all 5 2,2-dichlorovinyl diethyl phosphate of the active substance. 2,2-dichlorovinyl dipropyl phosphate Depending on the amount of insecticidal phosphoric 2,2-dichlorovinyl dibutyl phosphate ester present in such compositions containing compo 2,2-dibromovinyl dimethyl phosphate nent (d) this leaves for the latter a proportion ranging 2,2-dibromovinyl diethyl phosphate from about 4 up to about 90 percent of the total weight O 2,2-dibromovinyl dipropyl phosphate of the composition. 2-bromo 2-chlorovinyl dimethyl phosphate The compositions according to the invention have 2-bromo 2-chlorovinyl diethyl phosphate the property of a particularly high stability to aging, 2,2-dichlorovinyl ethylmethyl phosphate which permits a longer storage and in consequence, in 1,2 dibromo-2,2-dichloroethyl