Sprayable bird and animal pest repellant composition containing a tacky polyolefin and methods for the preparation and use thereof

Abstract: The invention provides a sprayable non-aqueous composition for repelling birds and animal pests, comprising a mixture of a tacky polyolefin, a substantially pure silica-based thixotropic agent and an organic solvent or diluent.

Description: The present invention relates to a sprayable bird and animal pest repellant composition and method. The task of deterring birds from resting on exposed surfaces such as window sills, roofs and ledges of buildings, statues and other public edifices is a problem of major concern. The damage caused by birds runs into many millions of dollars each year, for example, to airplane hangars and other airfield installations, to telephone and other cables, to other exposed electrical equipment and in warehouses. Bird droppings are also considered to be a health hazard. Thus, there is at the present day a need for a bird repellant composition which is convenient to use for both commercial and domestic applications, and which is weatherproof, that is to say, that it will be stable for an extended period of time when exposed to loci where birds are likely to roost or are known to roost. At the same time, such a composition should desirably be non-toxic to birds, pets, plants and humans. To the knowledge of the inventors, the only sprayable bird repellant which has been marketed hitherto is in the form of an aqueous emulsion which readily melts in hot weather and is washed away by rain. Other bird repellant compositions are smeared or painted on a surface, and do not have the convenience of a sprayable composition. SUMMARY OF THE INVENTION The present invention thus provides an aerosol propellant pressurized, sprayable non -aqueous composition for repelling birds and animal pests comprising 25 to 95% high molecular weight tacky polybutene, 0.5 to 6% of a substantially pure silica-based thixotropic agent, 5 to 75% solvent and 5 to 75% propellant by weight, which combination enables said composition to flow readily through a spray nozzle and then immediately coagulate upon contact with a sprayed surface without exhibiting creep even at temperatures of up to 130°C. Once applied, the composition is stable both in rain and sun for periods in excess of 12 months. In another embodiment the present invention provides a method for repelling birds and animal pests from a locus, which comprises applying by spraying onto the locus the sprayable composition recited above. Thus, the present invention provides a composition which may be sprayed onto a locus where birds are known to roost, or where it is expected that they may roost. The present invention excludes the use of any ingredient which is toxic to humans. Preferably also, the invention excludes the use of any ingredient which is toxic to birds and animal pests. The repellent effect on birds and animal pests, when applying the composition according to the invention is due rather to its tackiness, which is sensed by the birds and animal pests when they touch the composition and imparts an insecure sensation which deters subsequent attempts. The use of tacky polyolefins as animal and especially bird repellents is well known in the art. Thus, e.g., in U.S. Patent 3,306,817 from 1967 there is already described a method of repelling birds from a locus which comprises applying to said locus amorphous polypropylene in an amount sufficient to render said locus repellent to birds. In more recent U.S. Patent 4,693,889 there is described and claimed a bird repellent composition comprising 15-35 weight percent polyisobutylene having a Staudiner molecular weight of about 8,000 to 15,000. 20-50 weight percent paraffin oil, 0-15 weight percent isoparaffin oil, 0-6 weight percent organic modified montomorillonite and 15-45 weight percent kaolin clay. Similarly in European Patent Applications 84109216.6 and 87101049.2 by the same applicants, published under publication numbers 0136468 and 0240656 respectively, there are described and claimed bird repellent compositions including an effective amount of a polymer component which polymeric component includes at least one butene polymer or copolymer and an effective amount of a thickening agent. In the first of said European applications, the only thickening agent exemplified is Tixogel R which is an organiphilic clay and in fact, in the second application the claim already is limited to a clay-based thickening agent. Returning to the description in U.S. Patent 3,306,817 it can be noted that in the examples in said patent, amorphous polypropylene was deposited on a roosting bar with a spatula. In broadening language found in said patent it is stated that: "The amorphous polypropylene repellent of this invention can be applied to a locus from which birds are to be repelled by any suitable technique such as spraying, brushing, dusting and the like. Suitable aerosol containers having an inert propellent can also be used for conveniently dispensing the amorphous polypropylene. It is also within the scope of the invention to disperse the amorphous polypropylene in a volatile or a nonvolatile hydrocarbon or other organic solvent or dispersant. A suitable emulsifier can also be used for providing an aqueous dispersion of the repellent. To achieve a more uniform application of the repellent, it is generally preferred to apply it to the surface in a liquid carrier selected from the group consisting of water, acetone, kerosene, ethyl acetate, and isoparaffinic hydrocarbons which boil in the range of about 127 to about 427°C (about 260 to about 800°F). It is to be noted, however, that said patent does not exemplify or teach the manner in which a suitable aerosol can in fact be prepared. More importantly following the bare suggestion of said patent one cannot obtain a satisfactory aerosol. Thus, e.g. combining an amorphous polypropylene with a suitable solvent and propellant can result after due experimentation in a sprayable composition, however, such a composition does not remain on the locus sprayed and instead over a period of weeks, begins to evidence creep which both stains areas below those sprayed and reduces the repellent properties of the area initially sprayed until as said creep progresses, the originally sprayed area no longer possesses bird repellent properties. Preparation of an aqueous dispersion by introducing a suitable emulsifier as suggested by said patent is found to be even less effective in practice since such a composition is soon washed away by rain. Due to the lack of an enabling teaching in said patent and the apparent difficulties with preparing a suitable sprayable bird repellant composition, in the more than twenty years that has elapsed since the publication of said patent, no literature of which applicant is aware has again suggested, let alone taught, the application of a tacky bird repellent composition by spraying, despite the wide felt need for such a composition and the obvious advantages thereof. Thus, e.g., more recent U.S. Patent 4,693,889 teaches the preparation of a gel to be applied by means of a caulking gun and the above-mentioned European applications teach bird repellent compositions in a gel, bead or strip form for delivery in cartridges. As will be realised, gels delivered with caulking guns or with cartridges are extremely time-consuming to apply on large areas and on the other hand, are not readily applicable for domestic use such as the market of the householder troubled by pigeons which roost on their windowsills or the eaves of their homes. Aerosol Age, Volume 17, No. 7, July 1972, pages 16 to 17, Industry Publications Inc., Cedar Grove, US describes the use of Cab-O-Sil® as an additive in anti-perspirant compositions to prevent the hygroscopic powders contained therein from clogging the nozzle of an aerosol dispenser. U.S. 4,431,120 discloses an aerosol dispensing system for dispensing compositions containing a hydrocarbon propellant. Amorphous silicas or silicates are included in the compositions to adsorb the hydrocarbon. JP-A-58-101173 teaches aerosol adhesive compositions having a viscosity of 100-10,000 cps and containing styrene-butadiene rubber, ultra-fine silica powder and a tackifier. US 3734875 discloses an aerosol composition for repelling birds comprising polyisobutylene, at least one inert non-polar organic solvent and an aerosol propellant. Polymers structurally similar to polyisobutylene are stated as not having a satisfactory shelf-life when formulated with aerosol propellants. JP-A-55-153701 teaches a repellent adhesive consisting of polybutene, colloidal silica and diethylhexyl adipate. CH-A-341144 describes the use of silica-containing products for thickening liquids. While thixotropic agents in general and silica based thixotropic agents in particular, have been known for decades, heretofor it has not been suggested in the literature to combine thixotropic agents with tacky polyolefins to produce a bird repellent which can be sprayed on desired surfaces and which readily flows through the spray nozzle but then immediately coagulates upon contact with the sprayed surface without exhibiting creep even at temperatures of up to 130°C. The silica based thixotropic agents found to be effective in the compositions of the present invention are those available on the market and described as highly dispersed, highly pure amorphous silica. Especially preferred are CAB.O.SIL® fumed silica of Cabot Corp. U.S. and Aerosil® of Degussa. The tacky component of the present composition is high molecular weight tacky polybutene, e.g. polybutene of a molecular weight of about 2300. The organic solvent or diluent may comprise, e.g, at least one member selected from aliphatic hydrocarbons, aromatic hydrocarbons, alicyclic hydrocarbons, halogenated hydrocarbons, aliphatic alcohols, esters and ketones. It will be appreciated that the principal function of the solvent or diluent on the one hand, is to make the composition easier to handle than it would be without any solvent or diluent, but that on the other hand, the solvent or diluent will be desirably one which will readily evaporate when exposed to ambient conditions, leaving the mixture of other components which will be relatively stable under diverse conditions of weather (for periods of up to 12 months or more) and will therefore be effective to repel birds and animal pests for a long period of time. A first manner of applying the compositions of the present invention, especially on large surfaces is by pressurization from an essentially non-disposable refillable container, e.g., by pumping in a propellant at superatmospheric pressure. It will be appreciated that in principle any known types of spraying equipment may be used. When seeking to cover a large area, then by way of example only, the composition of the invention may be sprayed in parallel lines (for example, about 5-20 cm. wide), separated by e.g., about 2-3 cm. to spray the composition of the invention, in an amount such that after evaporation of the solvent, the thickness of the sprayed layer will be, e.g., approximately 1 mm. Such a composition comprises by weight 25 to 95% high molecular weight tacky polybutene, 0.5 to 6% of a substantially pure silica-based thixotropic agent and 5 to 75% solvent. High molecular weight polybutene is preferred for use in the present compositions because of its greater stability. Preferred compositions will comprise 40 to 70% high molecular weight tacky polybutene, 1.5 to 4% substantially pure silica-based thixotropic agent and 15 to 25% solvent. The present invention also provides a method for preparing the sprayable non-aqueous composition of the invention comprising combining (based on weight of final composition) 5 to 75% by weight of a solvent as herein defined and 0.5 to 6% of a substantially pure silica-based thixotropic agent and then slowly adding at substantially ambient temperature, 25 to 95% of high molecular weight tacky polybutene and pressurising with 5 to 75% propellant by weight. The present method obviates the need for heating and the cost involved therein which characterized the prior art processes described e.g., in European applications 84109216.6 and 87101049.2. The propellant present in the composition may comprise at least one component selected from carbon dioxide, nitrous oxide, argon, nitrogen, oxygen and mixtures thereof, such as for example, air. In the alternative, a propellant may comprise at least one member selected from propane, butane, isobutane, trichloromonofluoromethane, dichlorodifluoromethane, difluoromonochloromethane, difluoromonochloroethane, dichlorotetrafluoroethane, dichlorotrifluoroethane, monobromomonochlorodifluoroethane, monobromotrifluoromethane, trichlorotrifluoroethane, tetrafluoroethane, octafluorocyclobutene and dimethyl ether or mixtures thereof. As an example of mixtures, a propane/butane mixture in the range of about 10:90 to about 40:60 e.g., 20:80 o 25:75, may be used. Higher-boiling materials such as e.g., pentane and hexane which would be unsuitable for use as propellants on their own, could possibly be used as ingredients of propellant mixtures with lower-boiling components. In view of the flammability of hydrocarbon propellants and of dimethyl ether, and their explosive potentiality when admixed with oxygen, the usual precautions should be exercised when using these materials. Where there is no objection to the use of fluorocarbons (which are usually non-flammable) as propellants, it is particularly preferred that such propellant comprises a mixture of dichlorodifluoromethane and dichlorotetrafluoroethane. Insofar as certain countries, states and local authorities may have enacted legislation prohibiting the use of at least certain of fluorinated hydrocarbons as propellants due to a belief that they may cause irrevocable damage to the ozone layer, the present disclosure is not intended to invite use of such propellants contrary to this legislation. Indeed, the attention of the skilled person is directed to the alternative propellants which may be used in accordance with the invention. It will be appreciated that propellants about which concern has been expressed with regard to potential damage to the ozone layer are perhalogenated, ie., fully halogenated, fluorinated hydrocarbons. Consequently there is at the present time a continuing interest in fluorinated hydrocarbon propellants which are not fully halogenated, such as 1,1,1,2-tetrafluoroethane, 1,1-dichloro-2,2,2-trifluoroethane, difluoromonochloromethane and 1-chloro-1,1-difluoroethane. A particular hazard in the case of ethers such as dimethyl ether, is the possibility of forming explosive peroxides; therefore such propellants should not be used in the absence of effective peroxide formation inhibitors. Especially preferred for use in the aerosol compositions of the present invention are propellants which themselves are solvents for the tacky polyolefins and which immediately evaporate once sprayed. Aliphatic hydrocarbon propellants are thus especially preferred such as the mixtures of propane/butane mentioned above. A preferred aerosol propellant pressurized sprayable composition according to the present invention will comprise by weight 25 to 95% high molecular weight tacky polybutene 0.5 to 6% substantially pure silica-based thixotropic agent, 5 to 70% solvent and 5 to 75% propellant. Especially preferred is an aerosol composition comprising by weight 40 to 70% high molecular weight tacky polybutene, 1.5 to 4% substantially pure silica-based thixotropic agent, 15 to 25% solvent and 5 to 30% propellant. A most preferred aerosol composition comprises 50 to 55% high molecular weight tacky polybutene, 2 to 3.5% substantially pure silica-based thixotropic agent, 25 to 35% solvent and 14 to 18% propellant. It is to be understood that in general, any types of aerosol containers, which are known to those skilled in the art may be utilized in applying the present invention. Reference may be made, by way of example, to Sanders, Handbook of Aerosol Technology, Van Nostrand Reinhold Company, 2nd Edition 1979, the disclosures of which are incorporated herein by reference. A new type of aerosol container which has recently appeared on the market is the two-compartment piston can in which the product is filled from the top and the propellant from the bottom wherein the product in the compartment above the piston is under pressure from the propellant which remains in the bottom part of the can throughout use, and such containers can also be used as will be realized. As will be realized, the composition of the invention may be applied by spraying to any locus, from which it is desired to repel birds and animal pests. By way of example, the compositions may be sprayed onto roofs, airplane hangars, antennas, parabolic antennas and reflectors, solar heaters, ventilation ducts, air conditioners, roofing beams, window ledges, sheds and other buildings, and exposed electrical installations such as power lines and transformers at airports and in warehouses, and anywhere else, especially where it is known that birds roost or nest. It will be appreciated that while the present invention is especially directed to repelling birds, it will also be effective to repel. animal pests (including crawling insects such as ants) and in particular, e.g., reptiles and rodents, especially tree-climbing pests which damage fruit such as squirrels or hyrax, in which case the composition can be, e.g., sprayed around the base of a tree or on the tree-trunk. While the invention will now be described in connection with certain preferred embodiments in the following examples so that aspects thereof may be more fully understood and appreciated, it is not intended to limit the invention to these particular embodiments. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the scope of the invention as defined by the appended claims. Thus, the following examples which include preferred embodiments will serve to illustrate the practice of this invention, it being understood that the particulars shown are by way of example and for purposes of illustrative discussion of preferred embodiments of the present invention only and are presented in the cause of providing what is believed to be the most useful and readily understood description of formulation procedures as well as of the principles and conceptual aspects of the invention. EXAMPLE I In accordance with substantially known industrial procedures, a standard aerosol can of approximately 250-300 c.c. capacity was filled with an admixture of 100 g. composition [comprising approximately 37 g. tacky polybutene, 61 g. 1,1,1-trichloroethane and 2 wt.% highly dispersed silica (Aerosil 200)] and as propellant, 34 g. 80:20 butene-propane mixture. This composition, after spraying on a locus and evaporation of the solvent, has been found to be stable under diverse weather conditions for not less than 12 months. EXAMPLE II The following composition may be used in place of the admixture of Example I, namely, 100 g. composition [comprising approximately 3 g. polyisobutylene (Vistanex L 120, Exxon Chemicals Co.), 25 g. tacky polybutene "H-100", 10 g. glycerol ester of hydrogenated rosin, 30 g. 1,1,1-trichloroethane, 30 g. methylene chloride and 2 wt.% highly dispersed silica (Aerosil 200)] and as propellant, 34 g. 80:20 butene-propane mixture. EXAMPLE III In accordance with substantially known industrial procedures, a standard aerosol can of approximately 200 c.c. capacity was filled with an admixture of 90 g. composition [comprising approximately 50 wt% tacky polybutene, 48 wt.% solvent (1,1,-trichloroethane or a 50:50 admixture of 1,1,1-trichloroethane with methylene chloride) and 2 wt.% highly dispersed silica] and a propellant which comprised dichloro-difluoromethane (4 g.) and dichlorotetrafluoroethene (6 g.)]. EXAMPLE IV The following composition may be used in place of the admixture of Example III, namely, 95 g. composition (comprising approximately 50 wt.% tacky polybutene, 48 wt.% solvent (1,1,1-trichloroethane or a 50:50 admixture of 1,1,1-trichloroethane with methylene chloride) and 2 wt.% highly dispersed silica) and a propellant which comprised butene (3.75 g.) and propane (1.25 g.). It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative examples and that the present invention may be embodied in other specific forms without departing from the essential attributes thereof, and it is therefore desired that the present embodiments and examples be considered in all respects as illustrative and not restrictive, reference being made to the appended claims, rather than to the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Claims: An aerosol propellant pressurized, sprayable non-aqueous composition for repelling birds and animal pests comprising 25 to 95% high molecular weight tacky polybutene, 0.5 to 6% of a substantially pure silica-based thixotropic agent, 5 to 75% solvent and 5 to 75% propellant by weight, which combination enables said composition to flow readily through a spray nozzle and then immediately coagulate upon contact with a sprayed surface without exhibiting creep even at temperatures of up to 130°C. A composition as claimed in claim 1, comprising 40 to 70% high molecular weight tacky polybutene, 1.5 to 4% silica-based thixotropic agent and 15 to 25% solvent by weight. A composition as claimed in claim 1 or claim 2, wherein said propellant comprises at least one aliphatic hydrocarbon propellant which is a solvent for said tacky polybutene. A composition as claimed in claim 3, wherein said propellant comprises a mixture of propane and butane. A method for preparing the sprayable non-aqueous composition of any of claims 1 to 4 comprising combining 5 to 75% by weight of a solvent as herein defined and 0.5 to 6% of a substantially pure silica-based thixotropic agent, said weight percentage being based on the final composition and then adding thereto at substantially ambient temperature 25 to 95% of high molecular weight tacky polybutene and pressurising with 5 to 75% propellant by weight. A method for repelling birds and animal pests from a locus, which comprises applying by spraying onto the locus a sprayable composition according to any of claims 1 to 4. A method as claimed in claim 6, wherein the composition is applied by pressurization from an essentially non-disposable refillable container. A method as claimed in claim 6 or claim 7, wherein the pressurization is supplied by a propellant-pressurized system. A method as claimed in any of claims 6 to 8, wherein the composition is applied from a disposable aerosol container.

Inventors: YARKONY EITAN, YARKONY YAIR, YARKONY, EITAN, YARKONY, YAIR
Applicants: YARKONY EITAN, YARKONY YAIR, YARKONY, EITAN, YARKONY, YAIR
Application year: 1990
Main classification: A01N27
IPC codes: A01N25, A01N27