WO2007085640A2

WO2007085640A2 - Composition for impregnation of textiles

Info

Publication number: WO2007085640A2
Application number: PCT/EP2007/050754
Authority: WO
Inventors: Ole Skovmand
Original assignee: Intelligent Insect Control
Priority date: 2006-01-27
Filing date: 2007-01-26
Publication date: 2007-08-02
Also published as: EP2038474A2; BRPI0706764A2; CN103649409A; AP2008004566A0; HN2008001173A; AP2489A; CN103649409B; AP2011005668A0; WO2007085640A3; EA200801736A1

Abstract

An impregnated insecticide and/or repellent containing textile that after several washes comprises insecticide and/or repellent on the surface of the textile with improved properties.

Description

TITLE: Composition for impregnation of textiles such as nettings

FIELD OF THE INVENTION

The present invention relates to an impregnated insecticide and/or repellent containing textile that after several washes comprises insecticide and/or repellent on the surface of the textile with improved properties.

BACKGROUND OF THE INVENTION

Insect and arachnidae orders contain families that are pest to humans and animals because of their bites, aggressive behaviour and eventual transmission of diseases of viral, bacterial or parasitological character. The list includes Diptera (mosquitoes, gnats, sandflies, tse tse flies and other biting flies), Hemiptera (bedbugs), Siphanoptera (fleas), lice and (ticks). Many of these pests can be controlled by contact insecticides that can be applied on surfaces like walls or curtains, or by aerosol spraying. Recently, several tools have been developed with textile like mosquito nets, treated blankets, tarpaulins and tents. The advantage of these methods are that relative small surfaces are needed for the treatment compared to wall spraying and the effect can be long lasting which an aerosol application cannot. Such material is normally washed periodically and water based solutions of the insecticides without special additives for retention will thereby easily be removed. Experience has shown that it is difficult and expensive to make people re-establish the treatment of the textiles and it is thus an improvement to deliver such products to people with a technology that will tolerate the washing. Such technologies may be coatings or in-fibre impregnation. It is not enough that the insecticide resist the washing, it must also be available at the textile surface shortly after in a way that the protective effect is re-established.

A number of prior art documents describe "wash resistant" insecticide comprising textile. Representative examples are US2005/0132500A1 (Karl, et al), W003/034823 (Baecker), WO0137662 (Skovmand, et al), EP731208A2 (Samson), WO 95/17091 (Tucci), EP787851A1 (Samson) and US 6,896,892 (Dwight et al).

Common for all this prior art is that focus has been on making a "wash resistant" product, wherein the insecticide is not washed off during a defined washing and still is biologically active at the surface of the textile in relevant amounts. The reason for this is that the prior art strategy has been to get the insect killed by contact with the insecticide on the surface of the textile.

This is illustrated by that the test assay in the representative prior art above is based on direct contact of the insect (e.g. mosquitoes) to the surface of the textile comprising insecticide. In order to make the "wash resistant" insecticide comprising textile, the representative prior art above provides numerous different technical solutions such as use of a monomer of acryl or urethane in a polymerisation process in a water emulsion to trap the insecticide a coating (US2005/0132500A1 ); use of a copolymer binder that gives hydrophobicity to insecticide (no release when net dry) plus a dispersing agent that gives less hydrophobicity of insecticide to give a limited insecticide release when net is wetted during e.g. normal wash (W003/034823); a process where a polymer backbone of polyurethane, polyacrylic, poly isocyanates and poly lactic acids is used to form a film on the fibre yarn and in the dissolved and emulsified insecticide is caught in this film (WO0137662); use of polyvinyl acetate binder to preserve the insecticidal effect of the insecticide permethrin through several wash cycles (EP731208A2); use of starch encapsulated slow release formulations of the insect repellent DEET (WO95/17091 ); impregnation of fabric with a polymer binder [polyvinyl acetate (PVA)] and/or a cross-linking agent [urethane resin] where the insecticide is added in an emulsion with a thickening agent (EP787851A1 ); and net based on micro encapsulation with cyclodextrin (US6896892).

A further common technical element of the representative prior art above is that the insecticide incorporated in the textile is present as individual molecules or "aggregates" of a relatively small number of molecules. This is e.g. achieved by dissolve the insecticide in an adequate solvent before this is added to the textile to get the insecticide impregnated textile. An example of this is described in WO0137662A1 , where the working examples describe preparation of an insecticide comprising emulsion made by e.g. by first dissolving the insecticide into a solvent (e.g. acetone) and then mixed in a suitable oil (e.g. silicone oil and/or polypropylenglycol) together with an emulsifier (e.g. detergent) and finally in water to create a water in oil emulsion, wherein the insecticide is present in a dissolved form in the oil droplets in the water. For impregnation the insecticide comprising emulsion is applied to the textile.

Said in other words, by using the prior art impregnation processes one is not getting a textile, wherein the insecticide or repellent is present as "solid form" micro particles, such as e.g. solid micro particles comprising micro-crystal particles of insecticide e.g. coated with resin.

SUMMARY OF THE INVENTION

Overall, the problem to be solved by the present invention may be seen in the provision of an impregnated insecticide and/or repellent containing textile with improved properties.

One solution of the present invention is based on that the present inventor has identified that some prior art (e.g. Permanet®) newly impregnated, not washed, insecticide containing textiles (e.g. mosquito nets) is capable of, BEFORE first wash, to kill insects (e.g. mosquitoes) at some distance (at least up to 50 cm) from the textile (see example 1 herein). Said in other words, the insect "killing" effect can be extended in space and not solely linked to a contact effect, i.e. insect in contact with insecticide present on the surface on the textile (e.g. net). This is of course an advantage since insects may be kept away from the person below or behind the textile (e.g. mosquito net) and be killed upon entering the room and e.g., resting on a wall nearby. However, the present inventor also found that this "killing" effect extended in space essentially disappears after one wash of the same prior art insecticide containing textiles (see example 2). Said in other words, after one wash the prior art insecticide containing textiles are only capable of killing insects when the insects are in direct contact with the textile. For further details see e.g. working examples 1 to 3 herein.

Without being limited to theory, it is believed that before first wash sufficient insecticide evaporates from the textile surface (much larger than seen by the eye because of multi fibre structure) to kill the insects at some distance (around 50 cm) from the textile. However, after first wash the "excess" of insecticide has been washed away and there are only relevant amounts of insecticide on the surface of the textile, i.e. insecticide does not "evaporate" away from the textile in relevant amounts.

As discussed above, the prior art strategy has been to get the insect "killed" when they are in contact with the insecticide on the surface of the textile.

This discovery of the present inventors "opens the door" for developing a new strategy for making impregnated insecticide containing textiles (e.g. mosquito nets). Accordingly, as described herein the present inventor has developed a novel impregnated insecticide containing textile that is wash resistant (comprises relevant amount of insecticide on the surface of the textile after several washes) and which, contrary to the prior art insecticide containing textiles, is capable of killing insects (e.g. mosquitoes) at some distance (at least up to 20 cm) from the textile even after several washes of the textile.

As e.g. described in e.g. working examples 2 or 3 herein one way of making the novel textiles is to make adequate modifications of the insecticide impregnation composition (e.g. different modified ratios of resin and polymers). However, once the skilled person based on the present disclosure, knows the objective (textile shall also be capable of killing insect at some distance even after washes of the textile) then it is within the common knowledge for the skilled person to make a number different adequate insecticide impregnation compositions to obtain the functional objective as described herein.

Accordingly, a first aspect of the invention relates to an impregnated insecticide containing textile that after several washes comprises insecticide on the surface of the textile, characterised by that after a wash in 0.2 - 0.5 % soap water for 10 min (as described in WHO standard test for net swatches, WHOPES2005/11 ) it evaporates sufficient insecticide to kill insects present 20 cm from the textile (measured according to the assay of example 1 herein). The "WHOPES 2005/11 " wash test can be found in "Guidelines for Laboratory and Field testing of Long Lasting lnsecticidal Mosquito Nets, WHO/CDS/WHOPES/CDPP/2005.11". The WHO test is a standard test for washing net swatches. However, this established standard wash test may be used for washing a textile or net of interest in general in accordance with requirements as described herein.

The term "several washes" in relation to the term "impregnated insecticide containing textile that after several washes comprises insecticide on the surface of the textile" should be understood as a requirement in accordance with the above described prior art known "wash resistant" impregnated insecticide containing textiles. The "several washes" may be seen as from around 10 washes (more preferably around 20 washes) performed according to an established WHO wash standard procedure.

A second aspect of the invention relates to use of impregnated insecticide containing textile of the first aspect for killing insects.

In line of first and second aspect of the invention, a third aspect of the invention relates to a method for testing if an impregnated insecticide containing textile is capable of, after one wash, killing insects present 20 cm from the textile comprising following steps: (i) washing an impregnated insecticide containing textile that after several washes comprises insecticide on the surface of the textile;

(ii) testing if the washed textile evaporates sufficient insecticide to kill insects present at least 20 cm from the textile and if does the textile is capable of, after one wash, killing insects present at least 20 cm from the textile.

It is clear that one way of performing the wash of step (i) may be according to the WHO wash standard mentioned in relation to the first aspect of the invention. However, for the skilled person it is obvious that the objective of the washing step (i) is to make a wash that in the present context represent an example of a wash made by normal persons during normal life. Accordingly, in the present context the term "washing" of step (i) of the third aspect should be understood as a washing with washing "characteristic" corresponding to an established WHO wash standard such as WHO wash standard "WHOPES 2005/11".

Similar, it is clear that one way of performing the testing step (ii) may be a testing in measured according to the assay of example 1 herein. However, for the skilled person it is obvious that the objective of the testing step (ii) may be done in another way to achieve the same objective. In short, the testing system shall simple be a system where relevant insects are present at least 20 cm from the textile combined with an method to analyse if the insects, present at least 20 cm from the textile, are killed. Another solution of the present invention, with respect to the problem of providing impregnated insecticide and/or repellent containing textile with improved properties, is based on that the present inventor has identified that when the insecticide and/or repellent is present as solid form micro particles, such as e.g. solid micro particles comprising micro-crystal particles of insecticide e.g. coated with resin, in the textile one may get a more controlled (e.g. sustained) release of the insecticide and/or repellent to the surface of the textile. Further, it has been identified that if the size of the solid micro particles are bigger than 25 μm one it not getting the herein relevant advantageous effect. This is different from the prior art discussed above, since by using the prior art impregnation processes one is not getting a textile, wherein the insecticide or repellent is present as solid form micro particles. In working examples 4-5 herein are shown Electron Microscope (EM) photos of textiles that comprise solid form micro particles of insecticide.

Accordingly, a fourth independent separate aspect of the invention relates to an impregnated insecticide and/or repellent containing textile that after several washes comprises insecticide and/or repellent on the surface of the textile, characterised by that at least 50% of the insecticide and/or repellent is present as solid form micro particles in the textile and wherein at least 75% of the solid form micro particles in the textile are solid form micro particles with a particle size from 0.1 to 25 urn.

The term "several washes" should be understood as explained in relation to the same term of the first aspect of the invention.

Without being limited to theory, it is believed that the insecticide and/or repellent solid form particles may be seen as providing a low soluble "depot" of the insecticide and/or repellent. During time the insecticide and/or repellent is slowly dissolved in e.g. a surrounding coating and thereby released in a sustained controlled way to the surface of the textile.

A fifth aspect of the invention relates to use of the insecticide and/or repellent containing textile of the fourth aspect for killing and/or repelling insects.

A sixth aspect of the invention relates to a method for making a textile comprising insecticide and/or repellent solid form micro particles, of any of claims 5 to 14, wherein the method comprises following steps:

(A) making a suitable impregnation composition containing insecticide and/or repellent present as solid form micro particles;

(B) using this composition for impregnation of the textile. Textiles such as fabrics (e.g. nets) are normally fixated not to shrink after washing. This can either be obtained by heating the net or fabric to a temperature that slightly melt e.g. the yarns together or by a chemical coating that then must be wash stable. An impregnation chemical coating is made at lower temperature than used for heat fixation. In the prior art it has so far not been possible to combine the two processes specified as (a) the impregnation the insecticide and/or repellent to the textile and (b) the fixation of the textile. One reason for that is that the coating chemicals, used in the prior art (e.g. polymers comprising halogens) react with the active insecticide and/or repellent and destroy them at the temperatures needed for polymerising these chemicals. Accordingly, the problem to be solved by the seventh independent separate aspect of the invention below relates to a method where it is possible to combine the two mentioned processes above into a one step method for making both the (a) impregnation of the textile and (b) the chemical fixation of the textile. Such a one step method may provide considerable process savings.

Accordingly, a seventh independent separate aspect of the invention relates to a method for making an impregnated insecticide and/or repellent containing textile characterized in that two processes specified as (a) impregnation the insecticide and/or repellent to the textile and (b) fixation of the textile is integrated into one process, wherein the method comprises following steps:

(I) making the impregnation of insecticide and/or repellent onto the textile and the fixation of the textile as an integrated one process at a temperature within a range of 70-200⁰C, wherein the temperature is maintained stable (± 1O⁰C) during the integrated one process and wherein

(a) the impregnation process is based on use of monomers or short termed polymers that are capable of making poly-condensation or polymerisation processes (curing) to get a coating at the used temperature and capable of making the poly-condensation or polymerisation processes without formation of ionics (e.g., halogen) or free radicals, and wherein (b) the fixation process is based on use of a fixation additive (chemical fixation), wherein the fixation additive is capable of performing the fixation at the used temperature or wherein the fixation process is based on irradiation (e.g. Infra red, ULV or ultra sound) that either alone or in combination with an fixation additive provides the fixation of the textile;

(II) optionally removing surplus composition by pressing of the textile or netting; (III) drying the textile passively or actively at a temperature within 20-200⁰C; and

(IV) optionally curing the textile at a suitable temperature.

DRAWINGS:

Figure 1 : Shows Electron Microscope (EM) photos of textiles that comprise solid form micro particles of insecticide. For further details see working examples 4-5 herein.

DEFINITIONS: Prior to a discussion of the detailed embodiments of the invention is provided a definition of specific terms related to the main aspects of the invention.

Generally, all the definitions of the relevant terms herein should be understood as the skilled person would understand them in the present technical context.

"Curing" denotes a process following addition of a finish to textile fabrics in which appropriate conditions are used to effect a chemical reaction (e.g. polymerisation). Heat treatment for several minutes has been standard, But higher temperatures for short times (flash-curing) and long times at low temperatures and higher regain (moist Curing) are also used.

"Drying" is typically performed at lower temperature than curing, since drying does not as such directly relate to that conditions are used (e.g. heating) to effect a chemical reaction (e.g. polymerisation). Drying may be performed for a number of reasons, e.g. to remove excess of solvent.

"Fabric" denotes a flexible artificial material made up of a network of natural or artificial fibres (thread or yarn) formed by e.g. weaving, knitting or pressed into felt. An example of a fabric is a cloth, a net (e.g. a mosquito net), a tent etc.

"Felt" denotes a fabric (e.g. cloth or net) made without weaving (a non-woven) which is produced by matting, condensing and pressing fibers.

"Fibre" denotes elongated stringy natural, man-made or manufactured material. Natural vegetable fibers, generally consist of cellulose, examples include cotton, linen, and hemp. Natural animal fibers include spider silk, sinew, hair, and wool. Man-made fibres are those that are made artificially, but from natural raw materials (often cellulosic). Examples include fiberglass, rayon, acetate, cupro and the more recently developed Lyocell.

Synthetic fibers include nylon, acrylic, polyester, polyethylene and graphite fiber.

"Impregnated" in relation to impregnated insecticide and/or repellent containing textile denotes a textile onto which the insecticide and/or repellent is applied, e.g. by coating the insecticide and/or repellent.

"Impregnation" denotes a process for applying insecticide and/or repellent onto the textile, e.g. by coating and/or curing/drying to get an impregnated textile.

"Insecticide" denotes a chemical substance used to kill insects or an acaricide. "Repellent" denotes an active ingredient in a product that has the ability to repel insects such as e.g. fleas and ticks. A repellent is not as such capable of killing an insect.

"Textile" denotes any kind of woven, knitted, knotted, tufted or non-woven fabric. Textile also refers to the yarns, threads and wools that can be spun, woven, tufted, tied and otherwise used to e.g. manufacture a fabric.

Embodiments of the present invention are described below, by way of example(s) only.

DETAILED DESCRIPTION OF THE INVENTION

Insecticide containing textile - kill insects present 20 cm from the textile

As said above, a first aspect of the invention relates to an impregnated insecticide containing textile that after several washes comprises insecticide on the surface of the textile, characterised by that after a wash in 0.2 - 0.5 % soap water for 10 min (as described in WHO standard test for net swatches, WHOPES2005/11 ) it evaporates sufficient insecticide to kill insects present 20 cm from the textile (measured according to the assay of example 1 herein).

This first aspect relates to a technology that attach the insecticide to the textile in a way that allows it to diffuse rapidly through e.g. the coating after a washing has removed or reduced the amount bio-available and available insecticide for evaporation at the surface.

Accordingly, in a preferred embodiment the impregnated insecticide containing textile of the first aspect is characterised by that it evaporates sufficient insecticide to kill insects present 30 cm from the textile, more preferably 40 cm form the textile and even more preferably it evaporates sufficient insecticide to kill insects present 50 cm from the textile.

For a period of time, the textile (e.g. a fabric such as a net) can thus evaporate sufficient insecticide or a combination of repellent and insecticide to repel the insects from the room where it is hanging and even to kill insects that rest or hide in the room. After a certain number of washes, the insecticide concentration will be too weak to provide a distant repellent or killing effect, but will still repel and kill susceptible insects on contact.

Accordingly, in a preferred embodiment the impregnated insecticide containing textile of the first aspect is characterised by that after two washes (more preferably after three washes, even more preferably after five washes and most preferably after ten washes) it evaporates sufficient insecticide to kill insects present 20 cm from the textile. One preferred way of impregnation of the insecticide onto textile to get a textile having the functional characteristics as mentioned in relation to the first aspect (i.e. after one wash capably of killing insects present 20 cm from the textile) is to make a coating around the insecticide present on the textile (generally on the textile fibres).

The impregnation shall preferably be made so the insecticide is presented in a form that is low soluble in a coating surrounding the insecticide. The effect of such a coating is that it allows little dissolved insecticide in the coating and, upon solution in the coating, the insecticide will therefore "try to get out" of the coating or said in other words migrate to the surface ("bloom"). Made probably sufficient insecticide migrates in a controlled way to the surface to evaporate sufficient insecticide to kill insects present 20 cm from the textile.

Based on skilled persons common knowledge and the detailed instructions herein it possible for the skilled person to make such a coating in several ways (e.g. by using adequate polymers and binders).

Suitable examples include a flourocarbon polymer. Flourocarbon polymers are suitable oil repellent and thus allow little dissolved insecticide in the coating (low solubility of insecticide). A preferred flourocarbon polymer is a flourocarbon polymer selected from the group having a very large part of the molecule as a resine and only a small part of fluorocarbon polymer. The resin serves as the storage, the fluorocarbon gives the wash protection. A suitable commercial available example is Rufoguard® (from Rudolf Chemie, Germany). Other preferred polymers include polyurethanes, polyacrylics, poly-isocyanates and polylactic acids

In a preferred embodiment there are used short termed polymers. Preferably, the short termed polymers used are relatively long chained more than 1000 monomers long and mostly linearly arranged thus needing fewer contact points and less additives for polymerisation. This implies that the poly-condensation needs less energy, e.g. may be done a relatively lower temperature that gives a lower risk for destroying the insecticide and/or repellent. Suitable of long chained more than 10000 monomer are commercial available from Rhodia (Rhodopass®).

More preferably, there is made a "two layer" coating. One first layer surrounds the insecticide there is present on the textile fibres. In this first layer the insecticide shall have a relatively low solubility. A second layer is build on top of the first layer and this second layer shall preferably have a much lower solubility for the insecticide as compared to the solubility in the first layer. The effect of such a "two layer" coating system is that the first coating layer works as a "reservoir" for the insecticide. However, since there is a low solubility in this first layer the insecticide, upon solution in the coating, will "try to get out" and migrate to the second coating. In the second coating there is much lower solubility and the insecticide will therefore relatively rapidly bloom at the surface to evaporate sufficient insecticide to kill insects present 20 cm from the textile. An example of a suitable material for this first coating is a resin such as a synthetic resin (e.g. based on polyacrylate or polyvinyl). Preferably, there is made a relatively thick layer of resin in order for this first coating layer to have a relatively big "reservoir" capacity.

An example of a suitable material for this second coating is flourocarbon polymers (see above for preferred flourocarbon polymers).

In a very preferred embodiment, the impregnated insecticide containing textile of the first aspect of the invention and corresponding embodiments as described herein is further characterised by that at least 50% of the insecticide is present as solid form particles in the textile according to the fourth aspect of the invention and related embodiments as described herein. See e.g. the section below for further details with respect to insecticide solid form particles.

Insecticide and/or repellent containing textile - with solid form micro particles

As said above, a fourth independent separate aspect of the invention relates to an impregnated insecticide and/or repellent containing textile that after several washes comprises insecticide and/or repellent on the surface of the textile, characterised by that at least 50% of the insecticide and/or repellent is present as solid form micro particles in the textile and wherein at least 75% of the solid form micro particles in the textile are solid form micro particles with a particle size from 0.1 to 25 μm.

A preferred way to measure if at least 50% of the insecticide and/or repellent is present as solid form micro particles in a specific textile of interest is a method based on use of Electron Microscope (EM) photos. In working examples 4-5 and figure 1 herein are shown Electron Microscope (EM) photos of examples of textiles that comprise solid form micro particles in accordance with the present invention.

In order to measure if at least 50% of the insecticide and/or repellent is present as solid form micro particles in the textile one can make a representative number of EM photos of the textile (e.g. a fabric such as a net) of interest. With a representative number of EM photos is meant a suitable number from adequate samples of the textile (e.g. a fabric such as a net) of interest in order to have EM photos from different sites of the textile of interest, which from a technically objective point of view can be said to "cover" (represent) the whole surface of the textile (e.g. a fabric such as a net) of interest. It is within the skilled person common knowledge to determine what may be a representative number of EM photos for a specific textile of interest. As an example, for a typical commercial relevant mosquito net a representative number of EM photos could be 10 EM photos from different sites of the net to "cover" the whole surface of the textile. Based on these EM photos one can count the number and size of the herein relevant insecticide and/or repellent containing solid form micro particles objectively present within the textile. Since the skilled person generally knows how a specific textile of interest has been made (coating material etc) and the amount of coating material applied, the skilled persons can routinely calculate how much amount of e.g. coating material (e.g. surrounding the insecticide and/or repellent) that objectively, on average, would be present in the herein relevant insecticide and/or repellent containing solid form micro particles. From this is follows, that the skilled can routinely calculate how much amount of insecticide and/or repellent that objectively, on average, would be present in the herein solid form micro particles and thereby make a objective calculation of the total amount of insecticide and/or repellent that is present as solid form micro particles in a specific textile of interest. Since the skilled person generally knows the global amount of insecticide and/or repellent that has been used to impregnate a specific textile of interest, the skilled person knows how much insecticide and/or repellent the textile globally comprises.

In summary, since the skilled person routinely can make an objective calculation of the total amount of insecticide and/or repellent that is present as solid form micro particles in a specific textile of interest and how much insecticide and/or repellent the textile globally comprises it follows that the skilled person routinely can determine if at least 50% of the insecticide and/or repellent is present as solid form micro particles in a specific textile of interest.

The nets of the invention described in working examples 4-5 and shown as EM photos in figure 1 are examples of nets that comprises at least 95% of the insecticide and/or repellent is present as solid form micro particles.

Accordingly, in a preferred embodiment at least 60% of the insecticide and/or repellent is present as solid form micro particles in the textile, more preferably at least 75%, even more preferably at least 90% and most preferably at least at least 95% of the insecticide and/or repellent is present as solid form micro particles in the textile.

As illustrated in working examples 4-5 herein one example of the solid form micro particles are solid form micro particles comprising micro-crystal particles of insecticide and/or repellent coated with resin.

Accordingly, a preferred embodiment of the invention relates to the impregnated insecticide and/or repellent containing textile of the fourth aspect and related embodiments, wherein the solid form micro particles are solid form micro particles comprising micro-crystal particles of insecticide and/or repellent.

In examples 4-5 the micro-crystal particles of insecticide are coated with resin. However, it may be coated with numerous other suitable materials. Accordingly, in a preferred embodiment the solid form micro particles are solid form micro particles comprising micro-crystal particles of insecticide and/or repellent, wherein the micro-crystal particles of insecticide and/or repellent are coated with a suitable material such as e.g. resin.

In working examples 4-5 and figure 1 herein are shown Electron Microscope (EM) photos of examples of textiles that comprise solid form micro particles of insecticide. In this examples the size of the solid form micro particles are roughly from 0.25 to 10 μm.

Accordingly, in a preferred embodiment at least 75% of the solid form micro particles in the textile are solid form micro particles with a particle size from 0.1 to 20 μm, more preferably with a particle size from 0.25 to 15 μm, even more preferably with a particle size from 0.25 to 5 μm and most preferably at least 75% of the solid form micro particles in the textile are solid form micro particles with a particle size from 0.25 to 3 μm.

In example 4-5 the solid form micro particles are solid form micro particles comprising micro-crystal particles of insecticide coated with resin. In line of this, the particle size of the herein relevant insecticide and/or repellent containing solid form micro particles relates to the insecticide and/or repellent containing solid form micro particles physically presents as individual particles as such in the textile. Such insecticide and/or repellent containing solid form micro particle may include adequate coating material e.g. surrounding the insecticide and/or repellent.

As described herein, in e.g. working examples 4-5, relatively smaller solid form micro particles gives improved effects. Further, as illustrated in the EM photos of examples 4-5 one can measure the size of the solid form micro particles directly from the EM photos.

Examples of preferred insecticide and/or repellent are described below. In particular with respect to making insecticide and/or repellent micro crystals (as described herein), it is preferred that the insecticide must be able to form micro crystals or other forms of fine solid form micro particles in solvent or water mixtures.

As said above, a sixth aspect of the invention relates to a method for making a textile comprising insecticide and/or repellent solid form micro particles, of any of claims 5 to 14, wherein the method comprises following steps: (A) making a suitable impregnation composition containing insecticide and/or repellent present as solid form micro particles;

(B) using this composition for impregnation of the textile. Alternatively expressed, this sixth aspect may be seen as a preferred embodiment of the fourth aspect of the invention and embodiments thereof that relates to a textile comprising insecticide and/or repellent solid form micro particles, in accordance with the fourth aspect of the invention and embodiments thereof, wherein the textile is obtainable by a method comprising following steps: (A) making a suitable impregnation composition containing insecticide and/or repellent present as solid form micro particles;

(B) using this composition for impregnation of the textile.

Herein preferred techniques to make the suitable impregnation composition containing insecticide and/or repellent present as micro-crystal particles may be seen as techniques based on "standard" techniques generally known to the skilled person for making -crystal particles of a compound of interest. Herein mostly preferred techniques are described below.

One preferred method for making suitable impregnation composition containing insecticide and/or repellent present as solid form micro particles of step (A) is a method comprising following steps:

(1 ) dissolving the insecticide and/or repellent in an organic solvent (e.g. acetone) with relatively high solubility for the insecticide and/or repellent for total dissolution and as concentrated as possible (e.g. by heating to obtain a higher concentration of insecticide and/or repellent);

(2) mixing this (preferably at high speed) into another solvent with relatively low solubility of the insecticide (e.g. water) whereby micro-crystal particles ("precipitates") are formed to get an impregnation composition (e.g. a solution or dispersion) comprising solid form micro particles comprising micro-crystal particles of insecticide and/or repellent.

In a preferred embodiment the organic solvent of step (1 ) is a proper solvent with a high solubility for the insecticide. Suitable examples of an organic solvent is an organic solvent selected from the group consisting of acetone, hexane, heptane, ligroin and petroleum ether; aromatic hydrocarbon solvents such as benzene, toluene and xylene; halogenated hydrocarbon solvents such as chloroform, carbon tetrachloride, dichloroethane, chlorobenzene and dichlorobenzene; ether solvents such as diethyl ether, diisopropyl ether, dioxane, tetrahydrofuran and ethylene glycol dimethyl ether; ester solvents such as ethyl acetate and butyl acetate; nitro compounds such as nitroethane and Nitrobenzene; and dimethylformamide. Mixtures thereof may also be used.

The solution may be further diluted with a bulk solvent to provide a larger volume with a less toxic composition or a higher evaporation temperature. It may be needed to keep a temperature just below he boiling point of the component with the lowest boiling point to keep the insecticide from precipitating.

In a preferred embodiment the solvent with low solubility of step (2) is relatively cold in order to "stimulate" creating of the micro-crystal particles. Further, it is also preferred that the solvent with low solubility of step (2) comprises an emulsifier (preferably a detergent) in order to emulsify the created solid form micro particles (i.e. that the created micro-precipitate particles do not agglomerate into too large precipitates).

The size of the particles can be reduced by heating the first phase (step (1 )) and cooling the second (step (2)).

Preferably the mixing of step (2) is done under high speed homogenisation, but even a hand mixing can give good results.

The solvent with low solubility of step (2) may be water. In such as case the insecticide and/or repellent is dissolved in a solvent where it is has a relatively high solubility (step (1 )). A bulk solvent may be added where the insecticide has a relatively low solubility, but the concentration of this bulk solvent in the total solvent phase must be below the concentration where the insecticide precipitates in the solution. This concentration can be increased by heating the bulk solvent or the mixture of insecticide, solvent and bulk solvent. This solution is mixed into the water phase (step (2)). During this mixing, the insecticide immediately forms micro crystals and the mixture becomes a dispersion of insecticide micro crystals in a water phase. Preferably, the mixing of the solvent phase into the water phase is made with high speed homogenisation assuring a low particle size while using very low levels of detergent to avoid foam forming.

The solvent with low solubility of step (2) may be an organic or inorganic solvent. In such as case the insecticide and/or repellent is dissolved in the solvent with relatively high solubility (step (1 )), then mixed into a second solvent where it has low solubility (step (2)) under preferably high string, homogenisation or sonication. The insecticide will then precipitate in the mixture as small particles or crystals. The size of the particles can be reduced by heating the first phase and cooling the second. This mixture is then preferably emulsified into water with the help of adequate emulsifiers adapted mostly to the bulk solvent.

The impregnation of the textile of step (B) above may be done by applying the solid form micro particles containing impregnation composition of step (A) onto the textile, optionally removing excess of solvent and then make a suitable coating of the insecticide and/or repellent. This may herein be termed a two step process (i.e. first applying the solid form micro particles onto the textiles and then coat them afterwards).

However, in a preferred embodiment this may be done in a herein termed one step process, characterized by that the solid form micro particles containing impregnation composition of step (A) already before being used in the impregnation of the textile of step (B) comprises relevant additive material and other material relevant for making the coated textile (e.g. monomers of short termed polymers for polymerization coating; for the stabilisations of these coatings, optionally thickeners to prevent that the crystal dispersion sediment, optionally UV stabilisers, etc). Some or all of these additives may be added after or before mixing with the insecticide or repellent solution or dispersion in accordance with step (2).

The impregnation of the textile in accordance with step (B) above is preferably done by a) passing the textile (e.g. fabric such as a net) trough the impregnation composition containing insecticide and/or repellent present as solid form micro particles of step (A) or spraying the impregnation composition of step (A) on the textile at a temperature below the boiling point of the solvents; b) optionally remove the surplus of insecticide and/or repellent by e.g. pressing, centrifugation or vacuum absorption; c) drying the textile to precipitate the insecticide on the textile (e.g. fabric such as a net) and preferably start the polymerisation and coating formation of the protective chemicals; and d) optionally curing and/or fixation of the textile.

To prevent the precipitates, optionally crystals, of the insecticide to melt, the drying, curing and fixation temperature must preferably be below the melting temperature of the insecticide used.

Alternatively, the solvent phase includes insecticide, at least two solvents and one or several emulsifier. The insecticide is dissolved in the first solvent, mixed with the second in a way to obtain solid form micro particles as described above, and this suspension is then emulsified with water to form an O/W emulsion for impregnation. Fixation agent, UV protectants, process protectants etc are added to the water phase either before or after mixing with the solvent phase.

Preferably, in all cases, the solvents are evaporated during a drying phase at relatively elevated temperature. In this process, the insecticide and/or repellent solid form micro particles are deposited on or near the fibre surface and the coating chemicals around them. The drying process should preferably be sufficient long to provide at least a partial and ideally full polymerisation of the coating chemical.

One preferred way of impregnation of the insecticide and/or repellent onto textile in accordance with step (B) above is to make a coating around the insecticide present on the textile (generally on the textile fibres).

The impregnation shall preferably be made so the insecticide is presented in a form that is low soluble in the coating. The effect of such a coating is that it allow little dissolved insecticide in the coating and, upon solution in the coating, the insecticide will therefore "try to get out" of the coating or said in other words migrate to the surface. Made probably sufficient insecticide migrates in a controlled way to the surface of the textile. Based on skilled persons common knowledge and the detailed instructions herein it possible for the skilled person to make such a coating in several ways (e.g. by using adequate polymers and binders).

Suitable examples include a flourocarbon polymer. Flourocarbon polymers are suitable oil repellent and thus allow little dissolved insecticide in the coating (low solubility of insecticide). A preferred flourocarbon polymer is a flourocarbon polymer selected from the group characterised by having very long, mostly linear resins (urethanes or cryclics) of more than 1000 and preferably more than 5000 monomers. Other preferred polymers include polyurethanes, polyacrylics, poly-isocyanates and polylactic acids without side chains.

More preferably, there is made a "two layer" coating. One first layer surrounds the insecticide there is present on the textile fibres. In this first layer the insecticide shall have a relatively low solubility. A second layer is build on top of the first layer and this second layer shall preferably have a much lower solubility for the insecticide as compared to the solubility in the first layer. The effect of such a "two layer" coating system is that the first coating layer works as a "reservoir" for the insecticide. However, since there is a low solubility in this first layer the insecticide, upon solution in the coating, will "try to get out" and migrate to the second coating. In the second coating there is much lower solubility and the insecticide will therefore relatively rapidly bloom at the surface of the textile.

An example of a suitable material for this first coating is a resin such as a synthetic resin (e.g. based on polyacrylate or polyvinyl). Preferably, there is made a relatively thick layer of resin in order for this first coating layer to have a relatively big "reservoir" capacity.

An example of a suitable material for this second coating is flourocarbon polymers (see above for preferred flourocarbon polymers). As described above, the flourcarbon lawyer serves as a barrier that keeps the insecticide in two zones, either in the "reservoir" of the first coating (e.g. resin) or on the textile surface. The surface insecticide is replenished upon evaporation or washes off.

In a preferred embodiment there are used short termed polymers. Preferably, the short termed polymers used are relatively long chained (preferably with chains from 1000 to 20.000 monomers) thus needing fewer contact points and less additives for polymerisation. This implies that the polymerization/poly-condensation (curing) may be done a relatively lower temperature that gives a lower risk for destroying the insecticide and/or repellent

In preferred embodiment of the impregnated textile comprising insecticide and at least 50% of the insecticide is present as solid form micro particles in the textile, of the fourth aspect and embodiments thereof, is further characterised by that it is an impregnated insecticide containing textile of the first aspect of the invention and embodiments thereof, i.e. an impregnated insecticide containing textile that after several washes comprises insecticide on the surface of the textile, characterised by that after a wash in 0.2 - 0.5 % soap water for 10 min (as described in WHO standard test for net swatches, WHOPES2005/11 ) it evaporates sufficient insecticide to kill insects present 20 cm from the textile (measured according to the assay of example 1 herein).

Integrated one step process - impregnation and fixation of textile

As said above, a seventh independent separate aspect of the invention relates to a method for making an impregnated insecticide and/or repellent containing textile characterized in that two processes specified as (a) impregnation the insecticide and/or repellent to the textile and (b) fixation of the textile is integrated into one process, wherein the method comprises following steps:

(a) the impregnation process is based on use of monomers or short termed polymers that are capable of making poly-condensation or polymerisation processes (curing) to get a polymer coating at the used temperature and capable of making the poly-condensation or polymerisation processes without formation of ionics (e.g., halogen) or free radicals, and wherein

(b) the fixation process is based on use of a fixation additive (chemical fixation), wherein the fixation additive is capable of performing the fixation at the used temperature or wherein the fixation process is based on irradiation (e.g. Infra red, ULV or ultra sound) that either alone or in combination with an fixation additive provides the fixation of the textile;

(II) optionally removing surplus composition by pressing of the fabric or netting; and

(III) drying the fabric passively or actively at a temperature within 20-200⁰C.

The process temperature of step (I) is generally speaking higher temperature than normally needed for a simple coating, but it is a lower temperature than generally used for heat fixation. Typically it is between 120 and 18O⁰C, but fixation additives exist that can provide fixations at around 8O⁰C.

Preferably, the fixation additive is an additive selected from the group consisting of condensing polyurehanes and polyacrylates (e.g. Rhodopass from Rhodia), anionic stabilisers as used in colour stabiliser systems (like Ciba P and Cibafast 4595), polyurethanes polymerising as blocked isocyanates combined with boosters that prevent polymerisation before 12O⁰C (like in Rucoguard). Cationic boosters can normally not be used since they accelerate hydrolysis of the ester binding of the insecticides (where these are esters as pyrethroids, organophosphorates and carbamates). The water emusion of the additives is preferably weakly acid and never alkalic since most insecticides are destroyed in alkalies, especially fast at elevated temperatures. At all process temperatures, it is only possible to carry out the polymerisation of step (l)(a) with catalyser or accelerators that are not based on radical formation. One example is based on blocked iso-cyanates. Further, when insecticides with halogen active centres are used, polymerisation based on halogen-ion interaction cannot be used.

Preferably, polymer coating obtained in step (l)(a) is a polymer selected from the group consisting of flourocarbon polymers, polyurethanes, polyacrylics , poly-isocyanates and polylactic acids. A preferred flourocarbon polymer is a flourocarbon polymer selected from the group having a very large part of the molecule as a resine and only a small part of fluorocarbon polymer. The resin serves as the storage, the fluorocarbon gives the wash protection.

In a preferred embodiment there are used short chained polymers in step l(a). Preferably, the short termed polymers used are relatively long (preferably more than 1000 monomers long and mostly linearly arranged) thus needing fewer contact points and less additives for polymerisation. This implies that the polymerization/poly-condensation gives a lower risk for destroying the insecticide and/or repellent.

Examples of monomers or short termed polymers that are not suitable to be used in step (l)(a) are those that for polymerisation use free radicals and halogen reactions for polymerisation or kationic katalyzers that hydrolyse ester bindings..

In a preferred embodiment the integrated one step process for impregnation and fixation of textile according to the seventh aspect of the invention and relates embodiments is a process that gives

an impregnated insecticide containing textile that evaporates sufficient insecticide to kill insects present 20 cm from the textile, according to the first aspect of the invention and related embodiments; and/or

an impregnated insecticide and/or repellent containing textile that after several washes comprises insecticide and/or repellent on the surface of the textile, characterised by that at least 50% of the insecticide and/or repellent is present as solid form micro particles in the textile and wherein at least 75% of the solid form micro particles in the textile are solid form micro particles with a particle size from 0.1 to 25 μm, according to the fourth aspect of the invention and related embodiments.

Preferred embodiments relevant for all aspects of the invention as described herein:

Insecticide For all aspect and embodiments herein the insecticide is preferably an insecticide with a fast paralysing or killing effect of the insect and very low mammalian toxicity.

Preferred insecticides are insecticides belonging to the group of insecticidal compounds as described in US2005/0132500A1 , paragraph [0074] - [0145].

Among these, insecticides with low water solubility are most suitable for the process especially when wash resistance is important.

In a preferred embodiment the insecticide is a pyrethroid such as deltamethrin, etofenprox, alfacypermethrin, lambdacyhalothrin or cyfluthrin.

Newer insecticides with lower mammalian toxicity at use dosage are interesting alternatives, especially because vector insects rarely have developed resistance to these. Such new groups of insecticides are pyramidialmines (Pyrimidifen), Pyrazoles (Fipronil and Fenpyroxiamte), Pyrrols (clorfenapyr) and imidacloprid.

Where nets are used in mass campaigns, the alternative or supplemental insecticide may also be an insecticide with a sterilising effect thus to sterilise the mosquitoes and avoid the next generation of mosquitoes. Such insecticides can be of the benzoyl urea group such as 1-(alfa-4-(chloro-alpha- cyclopropylbenzylidenamino-oxy)-p-tolyl)-3-(2,6-diflourobenzoyl)urea, Diflubenzuron: N-(((3,5- dichloro-4-(1 ,1 ,2,2-tetraflouroethoxy)phenylamino) carbonyl)2,6 diflouro benzamid, Triflumuron: 2- Chloro-N-(((4-(triflouromethoxy) phenyl)-amino-)carbonyl) benzamide, or a triazin such as N- cydopropyl- 1 ,3,5 -triazine-2,4,6-triamin or other insecticides with a sterilizing effect on adult mosquitoes.

Repellent

For all aspect and embodiments herein the repellent is preferably a repellent belonging to the group of insecticidal compounds as described in US2005/0132500A1 , paragraph [0146].

Preferred examples of suitable repellent is a repellent selected from the group consisting of N, N- Diethyl-meta-toluamide (DEET) and N,N-diethylphenylacetamide (DEPA) and pyrethroids registered as repellents such as esbiothrin (3-allyl-2-methyl-4oxocydopent-2-(+)trans- chrysantemate)

Preferred textile - fabric In a preferred embodiment the textile is a fabric. A preferred fabric is a fabric selected form the group of fabric consisting of a net (preferably a mosquito net), bedding, blankets, curtain, and a cloth (such as a sock, a trouser or a shirt).

Preferably the fibres of the textile are fibres made of synthetic fibres such as nylon, acrylic, polyester, polypropylen and/or polyethylene. Blankets are in a preferred embodiment made of cotton or a cotton-polyester mixture.

Impregnated fabrics in dark colours can be used as mosquito traps. In this case, the insecticide shall preferably not be repellent, since the effect is not based on keeping the insects away, but on the contrary allow them to hide and rest on the fabric. Insects like mosquitoes hide during daytime in dark areas, and will thus search the impregnated fabric for hiding and get killed by the insecticide.

The impregnated fabric may also contain insecticide or repellent that repels or kills insects on distance and thus supplement or replace e.g. an impregnated net. It may be hanging in the bedroom and thus increase the effect of a bednet in the same room even when this is not impregnated. It may be used for cloth or blanket provided the insecticide is low toxic and has no skin irritating effect, e.g. like the pseudo-pyrethroid etofenprox.

Impregnation - drying/curing in general

For all aspect and embodiments herein is below described preferred impregnation processes including preferred drying/curing. Generally, the impregnation of the textile is preferably done by a) passing the textile (e.g. fabric such as a net) trough the impregnation composition containing insecticide and/or repellent or spraying the impregnation composition on the textile; b) optionally remove the surplus of insecticide and/or repellent by e.g. pressing, centrifugation or vacuum absorption; c) drying the textile to precipitate the insecticide on the textile (e.g. fabric such as a net) and preferably start the polymerisation and coating formation of the protective chemicals; and d) optionally curing and/or fixation of the textile.

The fabric (e.g. netting) is preferably dried, e.g. by a passing air stream, by passing under infra red lamps or ultra sound or simply in an oven. The fabric and especially the netting must preferably be kept fixed under this process not to change shape. The temperature used in the drying process must preferably be below the boiling point of the insecticide to avoid losses of insecticide during production that may cause environmental and workers safety problems. Chemical cross reaction between insecticide and the cross-linking agents or polymerisation molecules is temperature dependent and must be taken into consideration for optimal processing. Polymerisation based on radical forming must preferably be avoided and catalysers that hydrolyse ester-bindings are potentially damaging for many insecticides that contain esterbindings.

The impregnation process may also take place in a colouring or wash machine as used in the textile industry. Such processes have the advantage that they can apply a coating or impregnation to a textile after it is cut and sewed. Handling of the insecticide treated material is thereby reduced and the material is dried in a drying tumbler or - where it needs stretching during the drying process - in a machine that makes fixation of the size.

The fabric may also pass a roller that is partly dipped into the impregnation composition solution or emulsion and draw the solution or emulsion to the side of the net or fabric in contact with a roller.

The finished net or fabric may be impregnated with the impregnation composition dispersion, solution or emulsion by spraying the fluid phase on the net or fabric, e g in a modified washing machine or on a conveyor belt. The finished net or fabric can then be e.g. air dried or dried in dry tumbler or oven or under infra red light or ultra sound.

As described in detail herein, the impregnation composition solution or emulsion may further comprise one or more ingredients selected from detergents, stabilisers, agents having UV protecting properties, solvents, spreading agents, anti-migration agents, preservatives, foam forming agents, and anti-soiling agents.

Further agents to be used are anti-statics, anti-calcareous agents, and anti-curling agents. Furthermore, the composition according to the invention may also be incorporated into detergent mixtures used for washing cloth or in rinse fabric conditioner (fabric softeners). It should be considered that most fabric softeners are based on cationic detergents and that these may degrade insecticides. Special formulation considerations should be taken in this respect.

Impregnation with the insecticide is preferably carried out at temperatures below 200⁰C, preferably below boiling point of the solvent or insecticide with the lowest boiling point to reduce evaporation during this process. It may be carried out at room temperature or even in cooled environment or from a cold fluid phase.

The application of the insecticide and/or impregnation liquid may also be done by forming a foam of the emulsion with the composition and applying the foam on the netting or fabric. This process reduce the amount of liquid applied, and thus reduce the energy consumption during the succeeding drying process. The impregnation may be carried out by applying the emulsion with a simple sprayer as used in agriculture or for house spraying in mosquito control campaigns. This method is an alternative method and is very likely to be used to re-impregnate nettings or fabric previously impregnated with less effective impregnations or not impregnated. During spray application, precautions must be taken to avoid inhalation as with other mixtures containing insecticides. In addition, solvent removed by evaporation in a factory process is preferably recycled.

In the succeeding drying process, temperatures are preferably below 200⁰C to avoid that e.g. fast evaporation of solvent remove the insecticide. With a formulation wherein the diffusion ability in the specific formulation is high and wherein the vapour pressure of the insecticide is high, a lower drying temperature is sufficient or required. A temperature profile with varying temperatures during the drying and curing/fixation process may be used for optimal performance of the coating.

When the fabric is dense and thick, the ambient temperatures in the process may be higher than cited above as long as the temperature in the fabric does not exceed these limits. The curing may also include or consist of passing the fabric or netting by a heated surface under pressure such as an iron or a heated roller. During drying processes and curing the fabric or netting is mechanically fixated in a way to prevent change of the form.

According to the present invention, the impregnation process may also be carried out with very simple equipment. The fabric or net is dipped into the water emulsion or solution containing the claimed insecticide/repellent and the protective agent(s), suitable detergents to ease wetting and to stabilise the emulsion/solution with the concentrations needed. The superfluous water is pressed out either by hands or by a simple roller, the fabric, garment or net is laid horizontally and dried, preferably in the shadow. The curing/ may be improved by ironing at temperatures below 200⁰C.

In a further embodiment of the invention, the impregnation process as described herein may also take place before the fibres are spun, woven or knitted. The fibres impregnated according to the present invention relates to the single structure forming the garment. However, the impregnation may still be performed directly on the garment or on the final fabric, e.g., a mosquito net. The preferred nettings according to the present invention is in one example, a net made of 20 to 72 filaments spun to a fibre, the fibre is knitted to a net or alternatively woven to a fabric. The polymer used according to the invention is capable of substantially encompass the filaments or spun fibres of the fabric resulting in a superior protection from wash off and at the same time allowing the active ingredient to be released in an amount sufficient to perform the insect killing or repellent effect.

Protective (e.g. coating) material in general For all aspect and embodiments herein is below described preferred protective (e.g. coating) material.

The coating forming component may include polyurethanes, poly acrylics, poly isocyanates and polylactic acids mixed with polyflourocarbon or polysilicon derivatives or it may simply consist of a polymer forming shield formed from shorter polymers or monomers.

Amount of insecticide and/or repellent in the fabric

For all aspect and embodiments herein is below described preferred (typical) amounts of insecticide and/or repellent in the fabric.

It is clear that a textile (e.g. fabric) as described herein may comprise both an insecticide and a repellent. Further it may comprise two or more different insecticides and/or repellents. In a useful embodiment more than one insecticide is applied in accordance with the invention. Accordingly, one part of the fabric (e.g. netting) may e.g. be impregnated with one insecticide and another part with another insecticide thus to prevent insecticide resistance or obtain control when insecticide resistance is already present to one of them. The two insecticides should preferably belong to groups where cross resistance is not likely to play a major role.

A typical amount of insecticide and/or repellent is between 0.001 and 10% (dry weight) of the (dry) weight of the fabric (e.g. netting) dependent on e.g. the insectiddal efficacy of the insecticide and/or repellent. A preferred amount is between 0.05 and 1 % of the fabric dependent on the insecticide and/or repellent. For a pyrethroid like deltamethrin or alphacypermethrin, the preferred amounts are between 0.05 and 0.3 % of the weight of fabric. For a pyrethroid like permethrin or etofenprox, the preferred amounts are between 0.1 and 6 %.

A typical amount of protective agent (e.g. coating agent or e.g. UV filter) is between 0.001 and 10 % (dry weight) of the (dry) weight of the fabric or netting, depending on the chemical type of the protective agent.

The amount of protective agents and the amount of insecticide are dependent on many factors. Insecticide dosage must be sufficient to kill the insects, perhaps even slightly resistant insects (technically to remove heterozygous, resistant individual to delay onset of high resistance). Preferably, a sufficiently overdose must then be chosen as a stock (preferably of crystalline form) from which the bio-available insecticide can be drawn over a prolonged period, ideally several years despite repeated washing. Once this has been decided, the coating must preferably be either sufficient thick or crosslinked to be sufficient resistant to migration, to keep this at a needed minimum. The outer coating must preferably have a low solubility for the insecticide not to be the storage from which the insecticide is easily removed. For a fluorocarbon protection (coating) including the special flourcarbon with magnified resin layer (see above), the typical amount is between 0.1% and 10 %, preferably between 0.5% and 3%. For polyurethanes, polyacrylics , poly-isocyanates and polylactic acids the typical amount is between 0.01% and 10 %, preferably between 0.2 and 5 %.

Cross binding and linking agents and catalysers are typically added in a ratio of less than 1 :1 based on the amount of protective agent. These should preferably not be of types that destroy the insecticide as most radical and peroxides will. Most interesting are combinations of polymers that provide a chemical fixation of the net or fabric and at the same attribute to the protection of the insecticide without destroying it.

A typical amount of repellent used in combination with an insecticide or alone is 0.1% to 10% of the solvent or water emulsion, resulting in 0.001% to 1% of the impregnated netting or fabric on a dry weight basis.

Depending on the use of the final product, an UV filter may be added to prevent or reduce the inactivation of the sunlight of the insecticide and/or repellent. The UV filter should of course be chosen to match the UV absorption of the insecticide. Further, it should not act as a solvent for the insecticide and thus reduce the crystal formation and increase the migration rate in the coating.

In a further embodiment, the impregnated textile (e.g. fabric) according to the present invention may also comprise one of more components selected from water, solvents, preservatives, detergents, stabilisers, agents having UV protecting properties, spreading agents, anti-migration agents, preservatives, anti hydrolytic agents or anti-oxidizing agent, and soiling reducing agents. The soiling reducing agent is preferable selected from flourcarbons which is also a film forming coated agent according to the present invention. Accordingly, flourcabons may be added in case other film forming agents are used in order to reduce soiling of the impregnated product and to decrease wash off.

Aspects and embodiments - presented as "claims"

Aspects and embodiments of an invention may be presented as so-called claims. Below this is done for some aspects and embodiments of the present invention.

1. An impregnated insecticide containing textile that after several washes comprises insecticide on the surface of the textile, characterised by that after a wash in 0.2 - 0.5 % soap water for 10 min (as described in WHO standard test for net swatches, WHOPES2005/11 ) it evaporates sufficient insecticide to kill insects present 20 cm from the textile (measured according to the assay of example 1 herein).

2. The impregnated insecticide containing textile of claim 1 characterised by that after two washes 5 (more preferably after three washes, even more preferably after five washes and most preferably after ten washes) it evaporates sufficient insecticide to kill insects present 20 cm from the textile.

3. Use of an impregnated insecticide containing textile of claims 1 or 2 for killing insects.

10 4. A method for testing if an impregnated insecticide containing textile is capable of, after one wash, killing insects present 20 cm from the textile comprising following steps:

(i) washing an impregnated insecticide containing textile that after several washes comprises insecticide on the surface of the textile;

(ii) testing if the washed textile evaporates sufficient insecticide to kill insects present at least 20 15 cm from the textile and if does the textile is capable of, after one wash, killing insects present at least 20 cm from the textile.

5. An impregnated insecticide and/or repellent containing textile that after several washes comprises insecticide and/or repellent on the surface of the textile, characterised by that at least

20 50% of the insecticide and/or repellent is present as solid form micro particles in the textile and wherein at least 75% of the solid form micro particles in the textile are solid form micro particles with a particle size from 0.1 to 25 μm.

6. The impregnated insecticide and/or repellent containing textile of claim 5, wherein the solid form 25 micro particles are solid form micro particles comprising micro-crystal particles of insecticide and/or repellent (for example as micro-crystal particles of insecticide and/or repellent coated with resin).

7. The impregnated insecticide and/or repellent containing textile of claim 5 or 6, wherein at least 75% of the solid form micro particles in the textile are solid form micro particles with a particle size

30 from 0.1 to 20 μm, more preferably with a particle size from 0.25 to 15 μm, even more preferably with a particle size from 0.25 to 5 μm and most preferably at least 75% of the solid form micro particles in the textile are solid form micro particles with a particle size from 0.25 to 3 μm.

8. The impregnated insecticide and/or repellent containing textile of any of claims 5 to 7, wherein at 35 least 60% of the insecticide and/or repellent is present as solid form micro particles in the textile, more preferably at least 75% and even more preferably at least 90% of the insecticide and/or repellent is present as solid form micro particles in the textile. 9. The impregnated textile of any of claims 1-2 and 5-8, wherein the impregnation is made so the insecticide is presented in a form that is low soluble in a coating surrounding the insecticide and/or repellent.

5 10. The impregnated textile of claim 9, wherein the coating comprise a polymer selected from the group consisting of flourocarbon polymer, polyurethanes, polyacrylics, poly-isocyanates and polylactic acids.

11. The impregnated textile of claim 10, wherein there is used oligomer to make the polymer, 10 preferably wherein the short termed polymers used are relatively long chained (preferably more than 1000 monomers long and mostly linearly arranged thus needing fewer contact points and less additives for polymerisation).

12. The impregnated textile of any of claims 9 to 11 , wherein there is made a "two layer" coating, 15 wherein one first layer surrounds the insecticide there is present on the textile fibres and in this first layer the insecticide have a relatively low solubility, and a second layer is build on top of the first layer and this second layer shall have a much lower solubility for the insecticide as compared to the solubility in the first layer. 20

13. The impregnated textile of claim 12, wherein the material for the first coating is a resin such as a synthetic resin (e.g. based on polyacrylate or polyvinyl) and wherein there is preferably made a relatively thick layer of resin in order for this first coating layer to have a relatively big "reservoir" capacity.

25

14. The impregnated textile of claim 12 or 13, wherein the material for the second coating is a polymer selected from the group consisting of flourocarbon polymer, polyurethanes, polyacrylics, poly-isocyanates and polylactic acids.

30 15. A method for making a textile comprising insecticide and/or repellent solid form micro particles, of any of claims 5 to 14, wherein the method comprises following steps:

(B) using this composition for impregnation of the textile. 35

16. The textile comprising insecticide and/or repellent solid form micro particles, of any of claims 5 to 14, wherein the textile is obtainable by a method comprising following steps:

(A) making a suitable impregnation composition containing insecticide and/or repellent present as solid form micro particles; (B) using this composition for impregnation of the textile.

17. The method for making a textile of claim 15 or the textile of claim 16, wherein the method for making the impregnation composition containing insecticide and/or repellent present as solid form micro particles of step (A) is a method comprising following steps:

18. The method or textile of claim 17, wherein the organic solvent of step (1 ) is a proper solvent with a high solubility for the insecticide, such as an organic solvent selected from the group consisting of acetone, hexane, heptane, ligroin and petroleum ether; aromatic hydrocarbon solvents such as benzene, toluene and xylene; halogenated hydrocarbon solvents such as chloroform, carbon tetrachloride, dichloroethane, chlorobenzene and dichlorobenzene; ether solvents such as diethyl ether, diisopropyl ether, dioxane, tetrahydrofuran and ethylene glycol dimethyl ether; ester solvents such as ethyl acetate and butyl acetate; nitro compounds such as nitroethane and Nitrobenzene; and dimethylformamide. Mixtures thereof may also be used.

19. The method or textile of claim 17 or 18, wherein the solvent with low solubility of step (2) is relatively cold in order to "stimulate" creating of the micro-crystal particles; and/or the solvent with low solubility of step (2) comprises an emulsifier (preferably a detergent) in order to emulsify the created micro-crystal particles (i.e. that the created micro-crystal particles do not agglomerate into too large "precipitate" particles); and/or the size of the particles is reduced by heating the first phase (step (1 )) and cooling the second (step (2)); and/or the mixing of step (2) is done under high speed homogenisation.

20. The method or textile of any of claims 17 to 19, wherein the solvent with low solubility of step (2) is water.

21. The method or textile of any of claims 17 to 19, wherein the solvent with low solubility of step (2) is an organic or inorganic solvent, wherein the insecticide and/or repellent is dissolved in the solvent with relatively high solubility (step (1 )), then mixed into the second solvent where it has relatively low solubility (step (2)) under preferably high string and the insecticide will then precipitate in the mixture as small particles or crystals, wherein the size of the particles preferably can be reduced by heating the first phase and cooling the second and this mixture is then emulsified into water with the help of adequate emulsifiers preferably adapted mostly to the organic or inorganic solvent.

22. The method or textile of any of claims 17 to 21 , wherein the impregnation of the textile in accordance with step (B) above is done by a) passing the textile (e.g. fabric such as a net) trough the impregnation composition containing insecticide and/or repellent present as solid form micro particles of step (A) or spraying the impregnation composition of step (A) on the textile at a temperature below the boiling point of the solvents; b) optionally remove the surplus of insecticide and/or repellent by e.g. pressing, centrifugation or vacuum absorption; c) drying the textile to precipitate the insecticide on the textile (e.g. fabric such as a net) and preferably start the polymerisation and coating formation of the protective chemicals; and d) optionally curing and/or fixation of the textile.

23. Use of the insecticide and/or repellent containing textile of any of claims 5 to 8 for killing and/or repelling insects.

24. The impregnated insecticide containing textile characterised by that at least 50% of the insecticide is present as solid form micro particles in the textile of any of claims 5 to 8, wherein the textile is further characterised by that after a wash in 0.2 - 0.5 % soap water for 10 min (as described in WHO standard test for net swatches, WHOPES2005/11 ) it evaporates sufficient insecticide to kill insects present 20 cm from the textile (measured according to the assay of example 1 herein) in accordance with any of claims 1 to 2.

25. A method for making an impregnated insecticide and/or repellent containing textile characterized in that two processes specified as (a) impregnation the insecticide and/or repellent to the textile and (b) fixation of the textile is integrated into one process, wherein the method comprises following steps:

(I) making the impregnation of insecticide and/or repellent onto the textile and the fixation of the textile as an integrated one process at a temperature within a range of 70-200⁰C, wherein the temperature is maintained stable (± 1O⁰C) during the integrated one process and wherein (a) the impregnation process is based on use of monomers or short termed polymers that are capable of making poly-condensation or polymerisation processes (curing) to get a polymer coating at the used temperature and capable of making the poly-condensation or polymerisation processes without formation of ionics (e.g., halogen) or free radicals, and wherein (b) the fixation process is based on use of a fixation additive (chemical fixation), wherein the fixation additive is capable of performing the fixation at the used temperature or wherein the fixation process is based on irradiation (e.g. Infra red, ULV or ultra sound) that either alone or in combination with an fixation additive provides the fixation of the textile; 5 (II) optionally removing surplus composition by pressing of the textile or netting;

(III) drying the textile passively or actively at a temperature within 20-200⁰C; and

(IV) optionally curing the textile at a suitable temperature.

26. The method of claim 25, wherein the process temperature of step (I) is between 120 and 10 18O⁰C.

27. The method of claim 25 or 26, wherein the fixation additive is an additive selected from the group consisting of condensing polyurehanes and polyacrylates (e.g. Rhodopass from Rhodia), anionic stabilisers as used in colour stabiliser systems (like Ciba P and Cibafast 4595),

15 polyurethanes polymerising as blocked isocyanates combined with boosters that prevent polymerisation before 12O⁰C (like in Rucoguard).

28. The method of claim any of claims 25 to 27, wherein the polymer coating obtained in step (l)(a) is a polymer selected from the group consisting of flourocarbon polymers, polyurethanes,

20 polyacrylics , poly-isocyanates and polylactic acids.

29. The method of claim any of claims 25 to 28, wherein there are used short termed polymers in step l(a), preferably wherein the short termed polymers used are relatively long chained (preferably more than 1000 monomers long and mostly linearly arranged thus needing fewer contact points

25 and less additives for polymerisation).

30. The textile or method of any of the preceding claims, wherein the insecticide is a pyrethroid such as deltamethrin, etofenprox, alfacypermethrin, lambdacyhalothrin or cyfluthrin.

30 31. The textile or method of any of claims 5 to 30, wherein the repellent is a repellent selected from the group consisting of N,N-Diethyl-meta-toluamide (DEET) and N,N-diethylphenylacetamide (DEPA) and pyrethroids registered as repellents such as esbiothrin (3-allyl-2-methyl- 4oxocyclopent-2-(+)trans-chrysantemate)

35 32. The textile or method of any of the preceding claims, wherein the textile is a fabric, preferably wherein the fabric is a fabric selected form the group of fabric consisting of a net (preferably a mosquito net), bedding, blankets, curtain, and a cloth (such as a sock, a trouser or a shirt). 33. The textile or method of claim 33, wherein fibres of the fabric are fibres made of synthetic fibres such as nylon, acrylic, polyester and/or polyethylene.

34. The textile or method of any of the preceding claims, wherein the amount of insecticide and/or repellent is between 0.001 and 10% (dry weight) of the (dry) weight of the fabric (e.g. netting).

EXAMPLES

Example 1 : Assay to test insecticide effect on distance

To measure effect of an impregnated mosquito net on distance, the net was suspended in a room measured 2.5 x 2.5 meter and 2 m high. A 10X10X10 cm net cage was suspended in the room 50 cm from the net. 10 female Anopheles gambiae ss of a susceptible strain, 3 days old and non blood fed, but fed with sugar water were introduced into the cage at 6 PM. Their survival rate was measured at 7 AM the following morning plus after 24 hr and compared to that of a similar chamber with a non impregnated net. The measurements is showed in table below.

A net was tested in this assay. However, the principle of this assay may be used for testing any textile (e.g. a fabric) of interest. Further, it the assay is used to test effect at e.g. 20 cm, the net cage is simply suspended in the room 20 cm from the net.

Comparison of two nets with insecticides, BEFORE first wash, where one is made with a coating (Permanet®), the other with an in-fibre impregnation (Olyset®). These two nets represent the, at the filing date of the present patent application, only two commercially available WHO recommended long lasting ("wash resistance") nets.

Example 2: Comparison of two nets AFTER washing, one has no evaporation of insecticide after washing, the other has.

The data represent means of 4 consecutive days after washing the nets. The evaporation effect that kills mosquitoes on distance, is not re-established for the net with deltamethrin, whereas it is partly re-established for the net with alfacypermethrin. The alfacypermethrin net is made according to the present invention and the difference is due to evaporation rate due to formulation difference, the latter based on a permeable, polyurethane coating made in accordance with the present invention. Only the 24 hour mortality at 35 % is significant different from the control mortality with the untreated net.

Alfacypermetrhin formulation: alfacypermethrin 0,3 g, Xylene 1 g, emulsifier 0,05 g, polyurethane 3 g, UV filter 0,2 g, in 100 ml, pick up in net 70%. The polyurethane allows for an evaporation after washing and re-establish the distance effect.

Example 3: Fabric with distant effect:

This example relates to a net, of the invention, with good distant insect killing effect testes by use of assay of example 1.

Permethrin 3 g, Xylene 1 g, emulsifier 0,1 g, polyurethane 10 g, UV filter 3 g per 100 ml, pickup 75 %. The impregnation fluid consist an emulsion with the insecticide in oil droplets in a O/W emulsion. The UV filter may be added as a separate emulsion or emulsified with the insecticide. Upon drying, the water evaporates and the oils are absorbed into the polyurethane coating.

Example 4 and 5: SEM photos of two products with microcrystallines of different type due to different formulation method and solvent concentrations.

In figure 1 is shown EM photos to make a comparison of two formulations made in accordance with the present invention.

Sample Nr 12: high speed mixing, low Acetone cone, cold Water, small crystals packed in badly cured Flourcarbone resine. Wash Resistance after 23-25 washes.

Sample Nr 30: slow mixing, cold solvent high level Acetone, big crystals packed in badly cured Flourcarbone resine. Wash resistance after 15 washes.

As can be seen from figure, the sample preparation (nr 12) giving the smaller crystals at left has a better wash resistance. As can be seen from the EM photo, in sample nr 12 at least 75% of the solid micro particles in the textile are solid micro particles with a particle size from 0.5 to 2 μm, and in sample nr 30 at least 75% of the solid micro particles in the textile are solid micro particles with a particle size from 3 to 5 μm. In this example the solid micro particles are solid micro particles comprising micro-crystal particles of insecticide coated with resin.

Both net 12 and 30 are examples of nets made according to the present invention.

The net displayed as Net 12 are both processed by dipping into insecticide crystal water suspensions. The suspension making net 12 dissolved deltamethrin in acetone that was diluted with ethanol and heated until all visible crystals had disappeared. The solution was then poured into a solution of flourcarbon in cold water under high speed homogenisation. The suspension making net 30 was dissolved in acetone and ethanol mixture with enough acetone to avoid crystallisation. This solution was then mixed with room temperature water emulsion of flourcarbon. The differences in ratios of the two solvents, temperature of solvents and water phase, eventually the mixing method provided very different mean crystal size and after drying, quite different wash resistance.

Claims

1. An impregnated insecticide containing textile that after several washes comprises insecticide on the surface of the textile, characterised by that at least 50% of the insecticide is present as solid form micro particles in the textile and wherein at least 75% of the solid form micro particles in the textile are solid form micro particles with a particle size from 0.1 to 25 um and wherein the solid form micro particles are solid form micro particles comprising micro-crystal particles of insecticide (for example as micro-crystal particles of insecticide coated with resin).

2. The impregnated insecticide containing textile of claim 1 , wherein the impregnation is made so the insecticide is presented in a form that is low soluble in a coating surrounding the insecticide and the effect of such a coating is that it allows little dissolved insecticide in the coating and, upon solution in the coating, the insecticide will therefore "try to get out" of the coating or said in other words migrate to the surface.

3. The impregnated insecticide containing textile of claim 1 or 2, wherein at least 75% of the solid form micro particles in the textile are solid form micro particles with a particle size from 0.25 to 3 μm.

4. The impregnated textile of any of claims 1 to 3, wherein the textile comprises insecticide and is further characterised by that it is an impregnated insecticide containing textile that after several washes comprises insecticide on the surface of the textile, characterised by that after a wash in 0.2 - 0.5 % soap water for 10 min (as described in WHO standard test for net swatches, WHOPES2005/11 ) it evaporates sufficient insecticide to kill insects present 20 cm from the textile (measured according to the assay of example 1 herein).

5. The impregnated textile of any of the preceding claims, wherein there is made a "two layer" coating, wherein one first layer surrounds the insecticide there is present on the textile fibres and in this first layer the insecticide have a relatively low solubility, and a second layer is build on top of the first layer and this second layer shall have a much lower solubility for the insecticide as compared to the solubility in the first layer, wherein the material for the first coating is a resin such as a synthetic resin (e.g. based on polyacrylate or polyvinyl) and wherein there is preferably made a relatively thick layer of resin in order for this first coating layer to have a relatively big "reservoir" capacity, and wherein the material for the second coating is a polymer selected from the group consisting of flourocarbon polymer, polyurethanes, polyacrylics, poly-isocyanates and polylactic acids.

6. The textile comprising insecticide solid form micro particles, of any of the preceding claims, wherein the textile is obtainable by a method comprising following steps:

(A) making a suitable impregnation composition containing insecticide present as solid form micro particles; (B) using this composition for impregnation of the textile, wherein the method for making the impregnation composition containing insecticide present as solid form micro particles of step (A) is a method comprising following steps:

(1 ) dissolving the insecticide in an organic solvent (e.g. acetone) with relatively high solubility for the insecticide for total dissolution and as concentrated as possible (e.g. by heating to obtain a higher concentration of insecticide);

(2) mixing this (preferably at high speed) into another solvent with relatively low solubility of the insecticide (e.g. water) whereby micro-crystal particles ("precipitates") are formed to get an impregnation composition (e.g. a solution or dispersion) comprising solid form micro particles comprising micro-crystal particles of insecticide.

7. The textile of claim 6, wherein the organic solvent of step (1 ) is a proper solvent with a high solubility for the insecticide, such as an organic solvent selected from the group consisting of acetone, hexane, heptane, ligroin and petroleum ether; aromatic hydrocarbon solvents such as benzene, toluene and xylene; halogenated hydrocarbon solvents such as chloroform, carbon tetrachloride, dichloroethane, chlorobenzene and dichlorobenzene; ether solvents such as diethyl ether, diisopropyl ether, dioxane, tetrahydrofuran and ethylene glycol dimethyl ether; ester solvents such as ethyl acetate and butyl acetate; nitro compounds such as nitroethane and Nitrobenzene; and dimethylformamide; and wherein the solvent with low solubility of step (2) is water.

8. The textile of claim 6 or 7, wherein the impregnation of the textile in accordance with step (B) of claim 6 is done by a) passing the textile (e.g. fabric such as a net) trough the impregnation composition containing insecticide present as solid form micro particles of step (A) or spraying the impregnation composition of step (A) on the textile at a temperature below the boiling point of the solvents; b) optionally remove the surplus of insecticide by e.g. pressing, centrifugation or vacuum absorption; c) drying the textile to precipitate the insecticide on the textile (e.g. fabric such as a net) and preferably start the polymerisation and coating formation of the protective chemicals; and d) optionally curing and/or fixation of the textile.

9. The textile of any of the preceding claims, wherein the insecticide is a pyrethroid such as deltamethrin, etofenprox, alfacypermethrin, lambdacyhalothrin or cyfluthrin; and wherein the amount of insecticide is between 0.001 and 10% (dry weight) of the (dry) weight of the fabric (e.g. netting).

10. The textile of any of the preceding claims, wherein the textile is a fabric, preferably wherein the fabric is a fabric selected form the group of fabric consisting of a net (preferably a mosquito net), bedding, blankets, curtain, and a cloth (such as a sock, a trouser or a shirt).