[0001] The present invention relates to suspensionsof adherent microcapsules containing biologically activeingredients.[0002] It is known to encapsulate various materials,often by interfacial polycondensation. For instance,United States Patent No. 3,577,515 speaks of capsulescontaining dyes, inks, chemical reagents, pharmaceuti-cals, flavoring material, pesticides, herbicides, perox-ides and indeed anything which can be dissolved, sus-pended or otherwise constituted in or as a liquid en-closed by the capsule. United Kingdom Patent No.1,371,179 discloses the preparation of polyurea cap-sulesfor containing dyes, inks, chemical reagents, phar-maceuticals, flavoring materials, fungicides, bacteri-cides and pesticides such as herbicides and insecti-cides. United States Patents Nos. 4,046,741 ;4,140,516; 4,417,916; 4,563,212 and European PatentNo. 611,253 are concerned with encapsulation of vari-ous materials. Canadian Patent No. 1,044,134 is con-cerned with encapsulation of insecticides, particularlypyrethroids. Canadian Patent No. 1,179,682 is con-cerned with encapsulation of pheromones.A pendingUnited States Patent Application (attorney docketnumber 53319USA6A), filed on even date with this ap-plication, is also concerned with encapsulating variousmaterials, including biologically active materials suchaspheromones.[0003] The above-mentioned patents make useofvarious forms of interfacial polycondensation, particu-larly the formation of capsules having polyurea and/orpolyurethane/polyurea shell walls. The capsules madebythe various processes are said to range in diameterfrom about1 micronto about2 mm, but most fall towardsthe lowerend of this range, i.e., from about250 microns,or even 100 microns, down to about1 micron.[0004] The present invention relates to an aqueoussuspension of microcapsules containinga biologicallyactive material, which suspension further comprises anadhesive material in an amount effective to enable saidmicrocapsules to adhere to an intended substrate,wherein theadhesive material is in the form ofan aque-ous suspension of adhesive microspheres.[0005] For purposesofthe present invention, the term"biologically active™ means materials that affect the lifeprocesses of organisms. Materials that are biologicallyactive include herbicides, pesticides, pharmaceuticals,and semiochemicals, including naturally and artificiallyproduced pheromones.[0006] Microcapsules containing such biologically ac-tive ingredients and additionally containing an adhesivematerial advantageously may be applied by spraying.This is particularly advantageous inthe fields offorestry,agriculture and horticulture, where aerial spraying ispreferred asa means of application. The sprayed cap-sules are applied to foliage, to which continued contactis desired. For instance, insecticides and pheromones10203040502scribed herein, the microcapsules may be blown orwashed offof the foliageby windand rain. It is necessarythat any treatment to render the capsules adherentshould notbe atthe expense of other valuable proper-ties. For instance, for spraying foruse in forestry, agri-culture or horticulture the capsules are ideally discreteparticles that will remain in suspension in water, usuallywitha suspending agent. Adherent properties impartedtothe capsules should not havethe result that the cap-sules aggregate together in aqueous suspension. Suchaggregation wouldof course renderthe capsules unsuit-able forspraying and defeat the whole purpose ofthef5capsules. Furthermore, any material usedto impart ad-herent properties should not affect the integrity of theparticles; it should not dissolve or weaken the shell ofthe capsule.[0007] The present compositions are aqueous sus-pensions, which providesa significant advantage in use.Other compositions that deliver encapsulated insecti-cides and herbicides are solvent based, which isa sig-nificant disadvantage because such solutions releasevolatile organic compounds (VOCs) tothe environment25For purposes ofthe present invention,a volatile organiccompound (VOC) is any volatile organic material havinga vapor pressure at 20°C greater than 13 Pa (0.1 Torr(mm Hg)) that is not an active ingredient (e.g. an insec-ticide, herbicide orthe like). More preferably, VolatileOr-ganic Compounds may be defined as havinga vaporpressure at 20°C greater than 2.7 Pa (0.02 Torr) that isnot an active ingredient Because aqueous suspensionsofthe present invention need not contain any apprecia-ble amountof these undesirable VOCs,the overall com-35position is significantly more environmentally friendly.Preferred compositions ofthe present invention containno more than 5% VOC by weight, and most preferablycontain no more than 2% VOC by weight Jurisdictionssuch asLos Angeles and so forth that havea significantair pollution problem would find the present aqueoussuspensions tobe highly preferred due to their low pol-lution effect on the environment.[0008] Whileadhesive materials are sometimes usedin agriculture today to help herbicides and insecticides45stickto organic substrates, until now the latex has beenusedtoa limited extent only with unencapsulated chem-icals. Surprisingly, it has been found that incorporationof adhesive with microencapsulated biologically activematerials results ina composition that is still sprayablefroma conventional spraying apparatus. Contrarytoex-pectations, it has been found that the sticky microcap-sules ofthe instant composition do not agglomerate atthe spray orifice or in the storage vessel. During appli-cation, the adhesive latex associates withthe microcap-55sules and therefore does not entirely coatthe surfaceofthe target substrates. Becausethe adhesive is solubleor dispersible in water, the composition hasa limited buteffective lifetime on the target substrate before weather
