BRPI0616750B1 - textile material and methods of cloth treatment and insect pest control - Google Patents

Abstract

optimized insecticidal textile material. The present invention relates to a microencapsulated insecticide treated cloth and a method for treating the cloth with a composition comprising at least one microencapsulated insecticide and at least one polymeric binder. The coated or partially coated cloth maintains a sufficient amount of microencapsulated insecticide on the cloth surface to kill or repel insects, particularly mosquitoes, even after repeated washings. The cloth may be formed as a net, clothing or the like to protect against insect-borne diseases such as malaria. Also provided is a cloth treatment composition containing a suitable amount of at least one microencapsulated insecticide and at least one polymeric binder.

Description

TEXTILE MATERIAL AND METHODS OF TREATMENT AND INSECT PEST FIGHTING

Field of the Invention The present invention relates to a textile material such as a cloth, knitted articles, netting material, mosquito nets, sheets, curtains, tarpaulins or wall material that has been impregnated or coated with At least one microencapsulated insecticide to impart wash fixation or residual effect to the insecticide and to maintain the bioavailability of the insecticide, material production methods and material treatment compositions.

Background Many infectious diseases (eg malaria, dengue and yellow fever, lymphatic filariasis and leischmaniosis) that are responsible for debilitating or even killing humans and animals in many countries, particularly in tropical countries, are transmitted by insects. For example, the mosquito parasite Plasmodium falciparum accounts for over 25% of infant mortality outside the neonatal period. In certain parts of Africa, malaria has been ranked first by the World Bank in terms of disability-adjusted life years. Poorly developed and funded health services, as well as drug resistance, have hampered many medical efforts to improve the situation. More recently, efforts have focused on controlling transmitting insects.

[003] Methods for controlling these insects include surface treatment of hovels and houses, air spraying, and impregnation of curtains and mosquito nets. Nets and tissues treated with insecticides have been developed since the 1980s as a promising tool for malaria prevention in endemic countries. Potent and safe synthetic pyrethroids such as permethrin, deltamethrin, lambda-cyhalothrin, alpha-metrin and cyfluthrin are currently used to treat nets and curtains by dipping textile material in emulsions or insecticide dispersions or spraying on nets.

The use of pyrethroid insecticides to "impregnate" mosquito nets and curtains as a means of killing mosquitoes and other flies that land on treated materials is well known. This concept is based on how blood-sucking arthropods can come into contact with insecticide-treated substrate when attracted to a nearby host, for example, a person sleeping under a mosquito net.This promotes pest control, eg mosquitoes.

Since people tend to wash their mosquito nets, curtains and others from time to time, it is desirable to intensify the persistence of insecticides in treated materials by making them wash-proof to some extent. Studies have proven that long-lasting insecticide-treated nets (LLITNs) are more reliable in preventing vector-borne diseases compared to conventional nets, which have to be re-treated or re-impregnated with insecticide after just one or two washes. However, conventional insecticidal compositions do not provide sufficient wash fixation, and the present invention relates to a solution to this problem.

Summary of the Invention The present invention provides a microencapsulated insecticide treated nonwoven and a method for treating, coating or impregnating the nonwoven with a composition comprising a microencapsulated insecticide and a polymeric binder. The treated nonwoven maintains a sufficient amount of microencapsulated insecticide on the nonwoven surface to kill or repel insects, particularly mosquitoes, even after repeated washings. Nonwoven may be presented as a netting, cloth or the like for protection against insect-borne diseases such as malaria. Also disclosed is a micro-encapsulated insecticide treatment composition containing a polymeric tissue binder and a field kit comprising a first sachet containing at least one polymeric binder and a second sachet comprising at least one microencapsulated insecticide.

Description of Specific Modalities Although the present invention is susceptible to various embodiments in various ways, certain specific embodiments are described in detail below, it being understood that the present disclosure is to be considered as an exemplary embodiment of the present invention only. without limiting the specific embodiments or examples discussed.

Therefore, the invention features an insecticide treatment composition containing at least one polymeric binder and at least one microencapsulated insecticide. In one embodiment, the polymeric binder and microencapsulated insecticide are presented together in separate sachets and are combined together with water to form an aqueous treatment composition by an end user. In another embodiment, the polymeric binder is an ethyl vinyl acetate copolymer. In one embodiment, the binder is substantially free of polyurethanes such as post-dispersed polyurethanes or water soluble polyurethanes. In an additional embodiment, the insecticide is a pyrethroid, such as lambda cyhalothrin. In another embodiment, the insecticide is an organophosphate, such as pyrimiphos-methyl. The microencapsulated insecticide and polymeric binder bond or interact with one another to form a nonwoven coating which, in one embodiment, is a partial or discontinuous coating. The nonwoven is impregnated or partially coated (discontinuously) by dipping the nonwoven into a treatment composition as an aqueous composition comprising a dispersion of at least one microencapsulated insecticide and at least one polymeric binder. , and allowing the wet nonwoven to dry without the need for high temperature curing. The polymeric binder binds or adheres to the nonwoven and allows the microencapsulated insecticide to remain attached to the nonwoven even after several detergent washes and rinses, thereby prolonging the nonwoven insecticidal effectiveness.

Treatment of the nonwoven with the microencapsulated insecticide treatment composition described herein reduces the rate at which the insecticide is removed from the treated mesh during washings. Tissues treated with the microencapsulated insecticide and binder composition of the present invention provide longer-lasting insect knockdown and mortality effects than fabrics treated using compositions which do not have the combination of a microencapsulated insecticide and a polymeric binder. Wall materials treated with the composition of the invention exhibit, among other things, higher residual insecticidal effects.

The method presented here is a simple process that combines the use of polymeric binders and microencapsulated insecticides to attach insecticides to nets and other fabrics. Use of the method described herein results in a product that is superior to currently available nets and provides a more durable and effective insecticidal activity or effect on the surface of the net or nonwoven. The use of the treated nets and tissues presented here results in more effective control of troublesome arthropods and / or vectors, which is associated with a reduction in disease transmission.

Insecticide-treated or impregnated nonwoven can be used in the manufacture of various end-use articles such as, but not limited to, mosquito nets, cloths, sheets, curtains and tents. Alternatively, existing nonwoven fabrics and products may be treated and retreated with the insecticidal composition using the method described herein. The insecticide treatment composition of the invention (an aqueous composition comprising at least one microencapsulated insecticide and at least one binder) is also suitable for wall treatments and other residual spray applications. The nonwoven impregnation or treatment method using the insecticide composition results in a product that is superior in performance, simpler to use and less expensive than the currently available insecticide impregnation, treatment or coating methods during the useful life of a particular handled network. In addition, the materials used in the method are less hazardous to apply and more environmentally acceptable than some currently available. This is particularly due to the fact that the active ingredient is microencapsulated and presented in an aqueous based formulation. This can be particularly important when pesticide compositions, such as insecticides, are handled by humans, where contact with exposed skin can result in temporary itching, tingling, burning or numbness, called paraesthesia. Paresthesia involving the face is also known as “subjective facial sensation” or SFS.

Therefore, the present invention provides a method of treating fabrics for imparting wash-resistant insecticidal properties, comprising treating said nonwoven with an insecticidal effective amount of a liquid composition comprising at least one active ingredient. microencapsulated insecticide and at least one polymeric binder. In one embodiment, an aqueous treatment composition is employed. The treated nonwoven yarns are therefore coated or partially coated not only with the microencapsulated insecticidal active ingredient, but also with the polymeric binder. In one embodiment, the partial coating is a discontinuous coating of at least one substrate surface, such as a nonwoven. Those skilled in the art will appreciate that although the coating is discontinuous, for example at the micrometer level, the average binder and insecticide load per square meter of substrate may be substantially the same or within a statistically acceptable target for the entire treated substrate. The effect of the polymeric binder is to increase the adhesion of the microencapsulated insecticide substance to the nonwoven by effectively "sticking" the insecticide-containing microcapsules to the individual nonwoven threads to provide attachment to the wash while maintaining the bioavailability of the insecticide. While not wishing to be bound by theory, it is believed that the interaction between the polymeric microcapsule wall, the polymeric binder and the nonwoven enhances the wash fixation of the treated nonwoven.

The invention therefore provides woven or non-woven materials, the threads of which are coated or partially coated with a film of an adherent polymeric binder incorporating an active substance as a microencapsulated insecticide. In one embodiment, the invention features nonwoven or nonwoven material, the yarns of which are discontinuously coated or partially coated with a polymeric binder and a microencapsulated insecticide active substance. The nonwoven may be in the form of finished fabrics such as curtains, sheets, mosquito nets, furniture covers, or may be embedded in linings, carpets or other floor or wall coverings. Alternatively, the fabrics may be made for use in packaging such as bags for storing and transporting materials, including food subject to insect pest degradation. In addition, floor materials, such as carpets, or wall materials, such as material-treated wallpapers, are presented with increased residual insect control by applying the composition comprising at least one polymeric binder and at least one insecticide. microencapsulated.

In this regard, in another embodiment, the present invention provides a method of combating insect pests in a household, which comprises applying an insecticidal effective amount of a liquid composition comprising at least one microencapsulated insecticidal active ingredient. and at least one polymeric binder to a wall or floor surface of that residence.

Fabrics or nets to be treated may be made from natural fibers such as cotton, raffia, jute, linen, sisal, hemp or wool, or synthetic fibers such as polyamide, polyester, polypropylene, polyacrylonitrile or others. Polyesters are particularly suitable.

The impregnated, treated, coated or partially or discontinuously coated mesh or nonwoven according to the present invention may comprise the active ingredient in an amount of about 0.001% w / w to 95% w / w by weight of the insecticide. . In general, pyrethroid insecticides, such as lambda cyhalothrin, are used in an amount of 0.25% w / w to 0.33% w / w (insecticide weight / nonwoven weight). In another embodiment, the insecticidal active ingredient is applied to the target nonwoven in an amount of 10 to 100 mg a.i./m2 (approximate net weight 30-40 g / m2).

The method of the invention may be practiced using liquid compositions comprising any suitable microencapsulated insecticide that is effective against pests to be controlled, particularly mosquitoes and adult flies.

Particularly suitable polymeric binder materials for use in the invention are the range of Atlox ™ SemKote polymers available from Uniqema, such as ethyl vinyl acetate copolymers (E-100, E-105, E-115 and others), homopolymers polyvinyl acetate (P-140, P145) as well as acrylic and vinyl acrylic materials. Specific characteristics of suitable polymeric binders used are that (1) is compatible with the microencapsulated insecticidal composition employed (in particular the polyurea wall capsules), (2) is sufficiently miscible with water to allow standard aqueous based application methods. (by way of example, suitably miscible binders are those which are miscible with water in an amount of at least 10 wt%; more particularly at least about 30 wt%), (3) has a transition temperature of glass that allows simple air drying without the need for a thermal curing process (typically 0-15 ° C), and (4) may be employed in an amount sufficient to impart adequate adhesion properties of the microcapsules to the substrate to impart the fixation to the desired wash of the treated nonwoven while maintaining the bioavailability of the insecticide.

Optimum application rates of a particular binder as specified above for a particular microencapsulated insecticide, particular target substrates and a set of insect pressure conditions can be readily determined without undue experimentation by simple variation studies performed on substrates. or target fabrics such as polyester mosquito nets. The use of these optimal rates in the treatment of a target substrate, such as a nonwoven or wall, generally resulted in a partial or discontinuous binder coating, while achieving a target load of active ingredient per square meter of substrate. Overloading binder to achieve a continuous coating or binder film can result in nonwoven stiffness and loss of insecticide bioavailability.

For example, it has been found that a target load of 25-90 mg of real solid polymeric binders per square meter of nonwoven provides this important wash-fix balance and bioavailability while preserving the non-woven utility as a net. More particularly, a target loading of 25 - 600 mg of real solid polymeric binders per square meter of nonwoven is employed; more specifically from 100 to 400 mg; or from 125 to 250 mg. A binder loading of 100 to 400 mg per square meter, more particularly about 350 mg, is particularly suitable for polyesters.

If desired, the polymeric binders described herein may be combined or mixed with other known ingredients such as plasticizers, emulsifiers, surfactants, stabilizers (including UV light shields), fillers, antioxidants, fungicides, antimicrobials, antifoaming agents, drying aids, smoothing agents, pigments or other combination aids. In addition, thickeners or bulking agents may be added to the polymeric binder to control the viscosity of the binder and thereby achieve appropriate flow properties for the particular desired application. These materials are well known in the art.

Microencapsulated insecticidal active ingredients suitable for use in the treatment compositions and coated fabrics according to the invention are prepared by any suitable technique known in the art. For example, various processes for microencapsulating material have previously been developed. These processes can be divided into three categories: physical methods, phase separation and interfacial reaction. In the physical method category, the microcapsule wall material and core particles are physically placed together, and the wall material flows around the core particle to form the microcapsule. In the phase separation category, microcapsules are formed by emulsifying or dispersing the core material in an immiscible continuous phase, wherein the wall material is dissolved and forced to physically separate from the continuous phase, such as by coacervation, and deposit. around the core particles. In the interfacial reaction category, microcapsules are formed by emulsifying or dispersing the core material in an immiscible continuous phase and then causing an interfacial polymerization reaction to occur on the surface of the core particles. The concentration of the insecticidal active ingredient present in the microcapsules may range from 0.1 to 60% by weight of the microcapsule. In general, suitable microencapsulated insecticides are particles with diameters between 0.1 and 1000 µm.

In one aspect, suitable microcapsule wall materials are selected from polyureas, aminoplasts, polyurethanes and polyamides.

In one embodiment, polyurea microcapsules containing a suitable insecticide are prepared as exemplified in US Patent No. 4,285,720, which involves the use of at least one polyisocyanate, such as polymethylene polyphenylisocyanate (PMPPI) and / or tolylene diisocyanate ( TDI) as the prepolymer. In the creation of polyurea microcapsules, the wall formation reaction is initiated by heating the emulsion to an elevated temperature, when the isocyanate polymers are then hydrolyzed at the interface to form amines, which in turn react with non-polymers. hydrolyzed to form the polyurea microcapsule wall.

The present invention relates, but is not limited to, the following active insecticides for use in the treatment compositions, and the tissues include those selected from the group comprising synthetic pyrethrins and pyrethroids; azole, bisamide, oxadizine derivatives; chloronicotini them; nitroguanidine derivatives; triazoles; organophosphates; pyrroles; pyrazoles; phenyl pyrazoles; diacylhydrazines; biological / fermentation products, such as macrolides, including emamectin or abamectin; plant essential oils such as d-limonene and eugenol; carbamates and combinations of these types of compounds.

Thus specific microencapsulated insecticides include carbamate such as propoxur or bendiocarb, or an organophosphorous insecticide such as malation, pyrimiphos-methyl or fenitrothion or a pyrethroid or pyrethroid insecticide such as allethrin, bioalethrin, S-bioalethrin neopinamine, fenvalerate, permethrin, cypermethrin, alfamethrin, deltamethrin, cyhalothrin or lambda-cyhalothrin. Insecticide mixtures may be employed to enhance the effect and for resistance control reasons. In one embodiment, a mixture of a microencapsulated insecticide and a non-microencapsulated insecticide may be used. A specific example is a mixture of microencapsulated lambda cyhalothrin and non-microencapsulated deltamethrin.

In one aspect, microencapsulated insecticides suitable for use in the treatment compositions of the invention and treated fabrics include tefluthrin, permethrin, lambda cyhalothrin, resmethrin, deltamethrin, cypermethrin, cyphenothrin, cyfluthrin, deltamethrin, chlorpyrifos, phenoxycarb, diaziofen, nonzi-non, , methyl isothiocyanate, pentachlorophenol, tralometrine, chlorfe-napir, fipronil, neonicotinoids and combinations of these compounds. Examples of suitable neonicotinoids include, but are not limited to, thiametoxam, nitenpiram, imidacloprid, clotianindine, acetamiprid and thiacloprid. A specific class of pesticides for use in microcapsules is the cyhalothrin class, including lambda cyhalothrin and gamma cyhalothrin. Microencapsulated insecticides are employed at rates that depend on their activity levels for the intended end use. In one embodiment, suitable rates for the insecticide are the existing rates given on the labels of current pesticide products containing these insecticides. For example, the ICON® CS brands of microencapsulated lambda cyhalothrin available from Syngenta were found to be suitable.

In one aspect, target pests include insects belonging to the order Diptera (covering mosquitoes, rubber, pium, tse-tse flies and other biting flies), Hemiptera (covering bed bugs) and Siphonapte-ra (covering fleas). Target pests include Dictyoptera (covering cockroaches), Coleoptera (covering stored grain pests), Lepidoptera (covering moths) and Arachnids (covering mites and ticks). The present invention is particularly suited for the control of flying pests such as mosquitoes.

The treatment compositions used in the invention may also contain emulsifying or dispersing wetting agents, which may be cationic, anionic or nonionic. Suitable cationic type agents include, for example, quaternary ammonium compounds, for example cetyltrimethyl ammonium bromide. Suitable anionic agents include, for example, soaps, salts of aliphatic sulfuric acid monoesters, for example sodium aluryl sulfate, salts of sulfonated aromatic compounds, for example sodium dodecylbenzenesulfonate, sodium lignosulfonate, calcium or ammonium. or butylnaphthalene sulfonate, and a mixture of the sodium salts of diisopropyl and triisopropylnaphthalene sulfonates. Suitable nonionic agents include, for example, ethylene oxide condensation products with fatty alcohols such as oleyl alcohol or cetyl alcohol, or with alkyl phenols such as octyl phenol, nonyl phenol and octyl cresol. Other nonionic agents are the partial esters derived from long chain fatty acids and hexitol anhydrides, the condensation products of said ethylene oxide partial esters and lecithins.

In one embodiment, nonwoven treatment compositions which are to be used in the form of aqueous dispersions or emulsions are generally supplied in the form of a concentrate containing a high proportion of active ingredient or ingredients, said concentrate to be used. diluted with water prior to use (capsule suspensions may be mentioned, for example). These concentrates often need to withstand storage for extended periods and, after storage, be able to dilute with water to form aqueous preparations that remain homogeneous long enough to allow them to be applied by dipping or conventional spray equipment.

In another embodiment, a separate sachet of the polymeric binder is presented together with a separate package or sachet containing the microencapsulated insecticidal composition (such as Icon 10 CS, Icon 2.5 CS or other). These materials are then combined with water in a treatment vessel or tank to form a final treatment composition.

Therefore, the invention also features a field kit for treating or re-treating a nonwoven material, to impart wash resistant insecticidal properties to it, comprising a first sachet containing a pre-measured amount of hair. at least one polymeric binder and a second sachet containing a premeasured amount of an insecticide composition comprising at least one microencapsulated insecticide. As indicated above, such materials are then diluted by combining with water in a treatment vessel or tank to form a final treatment composition. Fabrics are treated with the treatment composition to impart wash-resistant insecticidal properties to them by spraying, dipping or curling the non-fabric into the treatment composition.

In one embodiment, the final treatment compositions may contain from 1 to 70% by weight of the insecticidal active ingredient in microencapsulated form and more specifically from 5 to 50% by weight. They may also contain from 1 to 70% by weight of the polymeric binder and more specifically from 1 to 25% by weight.

When the composition is diluted with water prior to use, it may be applied to the nonwoven by direct spraying, or by dipping or soaking the nonwoven in a bath containing the diluted composition. The nonwoven may be finished and prepared nonwoven, such as curtains (particularly net curtains), sheets, furniture covers or the like, or it may be a new nonwoven. In the latter case, treatment with microencapsulated insecticide may be carried out at the end of the manufacturing process by placing the microencapsulated insecticide composition in the final treatment bath.

Leaching of fabric insecticides during the washing process not only reduces the insecticidal effectiveness of the deposit on the nonwoven, but also allows the insecticides to pass into the wash water. By the use of the methods and compositions of the present invention (microencapsulated insecticide plus a polymeric binder), the wash fixation of the insecticide on the treated nonwoven can be significantly improved, as shown by the residual knocking and mortality effects on incoming insects. in contact with the treated nonwoven.

The invention is illustrated by the following Examples. Examples illustrating compositions of particular active ingredients may be considered as exemplary also of compositions wherein the active ingredient is replaced by others of similar efficacy.

Examples Example 1 A treated polyester mesh is prepared as follows: A 60 x 60 sample of a polyester mesh material was treated in the laboratory using a 1 liter volume of solution. of treatment. The composition of the 1 liter treatment solution was as follows: 16.2 g Icon 10CS * 30.0 g Atlox SemKote E-105 ** (55% solid binder) 953 g deionized water It is prepared in a plastic bottle, the mesh sample is carefully folded and rolled and placed in the solution, and the bottle cap is closed. The bottle is then rolled for 5 minutes, after which the net is carefully removed. Excess liquid is removed using absorbent paper, and the net is then hung to dry for 24 hours under ambient conditions.

Target load is 50 mg ai / m 2 (i.e. 0.5 g Icon 10CS as a 10% formulation), 350 mg solid polymer (i.e. 0.63 g SemKote E105 , as a 55% solution). * Lambda-cyhalothrin target load is 50 mg a.i. per square meter net, but due to losses incurred in the laboratory application process, the solution is “overloaded” with Icon. ** Binder retention studies have shown that this level of binder in solution for this application method results in a retention of only about 0.35% solid binder per square meter. Example 2 Nets prepared according to the procedures of example 1 are used in the following procedure except that “Ico-net” nets have no binder. Washing and bioassay cycles are performed following protocols similar to those published in WHO / CDS / WHOPES / GCDPP / 2005.11. The yield and mortality of Aedes aegypti after 3 minutes of exposure to the experimental mesh formulation containing Icon CS and polymeric binder are shown below: TABLE 1 Example 3 A treated polyester mesh is prepared as follows: [0042] ] Whole polyester mosquito nets (denier 75, 130 x 180 x 150 cm) were treated with Icon 2.5CS (25 g / L lambda-cyhalothrin) and polymeric binder by a manual immersion process as shown below.

The required amount of insecticide (target dose 50 mg ai / m 2) and binder was weighed and premixed. The mixture was then added to 500 mL of deionized water, ensuring that all formulation and binder was in solution. An entire mosquito net was then added to the solution and turned over. After turning for approximately 3 minutes, the net was removed without twisting and opened on the laboratory floor. After a drying period of 12-16 hours, the nets were folded and stored in aluminum foil.

Example 4 The effectiveness of nets prepared according to the procedures of Example 3 was evaluated using methods similar to those recommended in "Guidelines for Laboratory and Field Testing of Long-Lasting Insecticide Treated Mosquitoes" (WHO / CDS / WHOPES / GCDPP / 2005.11), except that “Icon CS only” nets do not have a binder, and the KO-Tab insecticide is not microencapsulated.

Table 2. Percentage of Aedes aegypti knockdown after 3 minutes of exposure to nets treated with Icon CS (50 mg ai / m2) and SemKote E105. Evaluation after 60 minutes. KO Tab 123: 25 mg ai / m2 deltamethrin + binder, mesh treated according to manufacturers instructions Table 3. Mortality percentage of Aedes aegypti after 3 minutes exposure to icon CS (50 mg ai / m2) and SemKote treated nets E105. 24-Hour Evaluation Example 5 Following known procedures, microencapsulated methyl pyrimiphos can be prepared by dissolving the insecticide in a suitable solvent, forming an aqueous-based emulsion of the desired droplet size, using emulsification aids and suitable dispersion and including suitable oil and / or aqueous phase monomers, and carrying out an interfacial polymerization at the emulsion interface, this results in a mobile solution of active ingredient encapsulated within continuous aqueous-phase polymeric shell microcapsules .

The nets are prepared following the procedures of Example 3, except for 20 mL of a 300 mg / L methyl CS pyrimidine formulation with 20 g of SemKote E105 in 500 mL of treatment water. This provides a network with 517 mg a. L and 948 mg of solid binder per square meter of mesh.

The foregoing description and examples are for illustration purposes only and do not limit the scope of protection that should be given to this invention.

Claims (15)

1. Woven or non-woven textile material made of synthetic fibers or selected mixtures of polyamide, polyester, propylene or polyacrylonitrile fibers characterized in that their yarns are partially or discontinuously coated with at least one polymeric binder and 0,025% w / w pa 0.33% w / w of at least one microencapsulated insecticide active substance selected from pyrimiphos-methyl and lambda cyhalothrin, wherein the microcapsule wall of the microencapsulated insecticide is selected from a polyurea, an aminoplast, a polyurethane and a polyamide. Textile material according to claim 1, characterized in that the binder is present at a loading of 25 to 950 mg per square meter of the woven material. Textile material according to claim 1, characterized in that the polymeric binder is water miscible in an amount of at least 10% by weight. Textile material according to claim 1, characterized in that the polymeric binder has a Tg of 0 - 15 ° C. Woven material according to claim 1, characterized in that the polymeric binder is an ethyl vinyl acetate copolymer. Textile material according to claim 1, characterized in that the fiber is polyester. Textile material according to claim 1, characterized in that the microcapsule wall of the microencapsulated insecticide is a polyurea. A method of treating rags, characterized in that said cloth is an insecticidally effective amount of a liquid composition comprising at least one microencapsulated insecticide-active ingredient selected from pyrimiphos-methyl and lambda cyhalothrin and at least one polymeric binder, in a manner such as whereas rag-resistant insecticidal properties are imparted to the cloth; wherein the microcapsule wall of the microencapsulated insecticide is selected from a polyurea, an aminoplast, a polyurethane and a polyamide. Method according to claim 8, characterized in that the binder is applied in an amount which provides a binder loading of 25 to 950 mg per square meter of the cloth. Method according to claim 8, characterized in that the microcapsule wall of the microencapsulated insecticide is selected from a polyurea. Method according to claim 8, characterized in that the polymeric binder is an ethyl vinyl acetate copolymer. Method according to claim 8, characterized in that the cloth is an open polyester weft net. A method of combating insect pests in a home, characterized in that it comprises hanging a cloth as defined in claim 1, in the home, so that it is accessible to insect pests. Method of treating cloths made of synthetic fibers or selected blends of polyester, polypropylene or polyacrylonitrile fibers, characterized by preparing a treatment composition by combining the contents of (i) a first sachet containing a pre-measured amount of at least a polymeric binder and (ii) a second sachet containing a pre-measured amount of an insecticidal composition comprising at least one microencapsulated insecticidal ingredient selected from pyrimiphos-methyl and lambda-cyhalothrin, with water to form a treatment composition; and treating said cloth by spraying, dipping or soaking the cloth in the treatment composition such that wash resistant insecticidal properties are imparted to the cloth; wherein the microcapsule wall of the microencapsulated insecticide is selected from a polyurea, an aminoplast, a polyurethane and a polyamide. An insect pest control method in a household comprising applying an insecticidal effective amount of a liquid composition characterized by at least one microencapsulated insecticide active ingredient selected from pyrimiphos-methyl and lambda-cyhalothrin and at least one binder polymeric, for a wall or floor surface of that residence, wherein the microcapsule wall of the microencapsulated insecticide is selected from a polyurea, an aminoplast, a polyurethane and a polyamide.