WO2012069049A1

WO2012069049A1 - A product with low density polymer resin releasing fipronil in a controlled way and use of such a product

Info

Publication number: WO2012069049A1
Application number: PCT/DK2010/050316
Authority: WO
Inventors: Mikkel Vestergaard Frandsen; Sebastien Gouin; Hoan Ngoc LÊ; Cuc Thu Nguyen
Original assignee: Vestergaard Frandsen Sa
Priority date: 2010-11-23
Filing date: 2010-11-23
Publication date: 2012-05-31
Also published as: TW201234961A

Abstract

A product (for example a mosquito net) with a thermoplastic resin containing Fipronil distributed throughout the resin by incorporation, wherein the resin without insecticide has a density of 0.890 to 0.930 g/ccm. The resin consists typically of linear low density polyethylene (LLDPE) and high density polyethylene (HDPE), with a ratio between LLDPE and HDPE between 80:20 and 30:70. The resin releases Fipronil in a controlled way providing long lasting activity.

Description

A PRODUCT WITH LOW DENSITY POLYMER RESIN RELEASING FIPRONIL IN A CONTROLLED WAY AND USE OF SUCH A PRODUCT

Field of the Invention

The present invention relates to a product with a polymer resin comprising Fipronil distributed throughout the resin by incorporation. It also relates to a method for pro- tecting crops, animals, or humans against insects by using such a product.

Background of the Invention

In connection with insecticide control, it is well known that insecticides can be integrated in polymer material in order to prevent insects to work their way through the material. However, when it comes to the control of release rates of insecticides in a polymer resin, this is regarded as a difficult issue, because a release that is too rapid exhausts the resin quickly with regard to insecticidal effect, and a too slow release does not have the desired efficiency or suitable regeneration properties in case the insecticide falls off or is removed, for instance, by washing. The picture is even more complicated, if the insecticide tends to crystallise on the surface of the product - called chalking - which leads to extraction of the insecticide from the bulk of the polymer due to the changed gradient caused by the crystallisation.

Adjustment of the polymer composition in order to achieve proper migration rates for insecticides is well known. For example, international patent application Wo02/43487 by Van Voris et al and assigned to Syngenta discloses a mixture of insecticide and HDPE (High Density PolyEthylene) and LDPE (Low Density PolyEthylene) and states that the selection of the polymers depends on the desired release rate. However, the release rates for insecticides, typically, also depend on the insecticide and on the form of the polymer resin. For example, sheets have a different release rate than fibers, and the polymer blend has to be adjusted accordingly. Also, the type of insecticide influences the migration rate, as well as the physical state, for example crystalline or fluidic.

Fipronil is a phenylpyrazole insecticide which - among a variety of insecticide - has been proposed for incorporation in polyethylene matrices. Use of Fipronil in connec- tion with buildings, such as under the floor, inside and around houses is disclosed in US patent No. 6370834 assigned to Super Sack. Fipronil could be considered advantageous for fighting mosquitoes that are resistant against pyrethroids, which are typically used in bednets, especially deltamethrin and permethrin. However, this would require that a proper polymer resin is found in which Fipronil migrates at a sufficient rate from inside the polymer to the surface of the polymer in order to replenish the surface content of insecticide.

Japanese patent application JP 06-316332 by Sumitomo issued as JP 3336714 discloses a Linear Low Density Polyethylene (LLDPE) resin with an insecticide, preferably permethrin or pyriproxyfen. The LLDPE is generally a copolymer of ethylene and at least one a-olefin selected from a-olefins having 4 to 12 carbon atoms. The density of the LLDPE is given as 0.870 to 0.935 g/ccm, and preferably 0.870 to 0.915 g/ccm. A large number of insecticides are mentioned, including carbamates, pyrethroids and Fipronil.

International patent application Wo2008/0001926 by Sumitomo discloses a resin composition for an extruded filament. The composition comprises an ethylene homopoly- mer with a density of 935 to 965 kg/m3 and a pesticide of 0.1 to 10 parts by weight per 100 parts by weight of the ethylene homopolymer. The composition has a melt flow rate of 0.3 to 7 g/10 minutes and a melt flow rate ratio of 10 to 50 and a density of 935 to 980 kg/ccm. It also discloses a permethrin+LLDPE masterbatch which is blended with HDPE before filament extrusion. Fipronil is mentioned as a possible insecticide among many others. A resin with a blend of HDPE and LLDPE is disclosed International patent application WO2010/0046348, where also a textile product with two types of yarn is proposed. The first type comprises pyrethroid and the second yarn Fipronil; the preferred yarn for the pyrethroid is a blend of equal amounts of HDPE and LLDPE, and the Fipronil yarn has at least 6 times more HDPE than LDPE.

As it appears from the above, there are various proposals in the prior art for resins containing Fipronil. No clear advice seems to be given, whether the density should be low, as in JP 06-316332, or high as in Wo2008/0001926 and WO2010/0046348. Also, no satisfying products, like mosquito nets, have found way to the market. Thus, and there is still a need for improvement for a long lasting polymer resin with migrating Fipronil. Object of the Invention

It is the object of the invention to provide a product with a polymer resin, especially flat yarns, having good migration properties of Fipronil. Predominantly, it is a purpose of the invention to provide a suitable carrier for Fipronil with a long lasting insecticidal effect on insects, especially mosquitoes. It is also the purpose to find a method for in- sect control, especially mosquito control, with reduced risk for humans, farm animals, and crops

Description of the Invention

This object is achieved by a resin with a density of 0.890 to 0.930 g/ccm, for example, 0.890 to 0.920 g/ccm. The term "ccm" stands for cubic-centimetre. The density is given for the resin without insecticide. Fipronil is distributed throughout the resin by incorporation and will migrate from the bulk of the resin to the surface of the resin.

The term "resin" in connection with the invention means the resin as used for the shape-giving process in the production of a product, for example extrusion or mould- ing. For example, the resin is a single polymer, or the resin is a blend of polymers. Not meant by the term "resin" is a polymer that is blended or copolymerized with other polymers before moulding or extrusion of a product or part of a product, for example a fibre or film. As has turned out by experimentation, a proper migration of Fipronil, which is useful for long lasting insecticidal products, especially mosquito nets and wall coverings, requires very special properties and limited parameters for the resin.

Although, this resin has been found especially useful for flat yarns containing Fipronil, the invention has a more general character and can be used for matrices of other kinds, for example fibres, films, or cylindrical filaments. The term "incorporation" means that the insecticide is distributed throughout the resin, for example as a dispersion. The insecticide may be fully or partly dissolved in the polymer, for example partly present as crystals and partly dissolved. The crystals may act as reservoirs that get gradual dissolved in the resin for replenishing the content of the insecticide. Using incorporation technologies, especially in thin products, for example, fibres, has the advantage over thin coating technologies, such as impregnation, of protecting the Fipronil against degradation by hydrolysis.

The term "long lasting" means more than 3 months, preferably more than 1 year or 2 years, rather more than 3 or 4 years, such as 5 years.

For all Intervals given as from a first value to a second value or between a first and a second value, the intervals are either open intervals or closed intervals. All %-values are given as weight percentages. Percentages of concentrations of Fipronil relative to the resin means relative to the weight of the resin without Fipronil, unless otherwise stated; thus, 0.5% Fipronil refers to 5g Fipronil in addition to 1 kg of resin. The term "dominantly" means a concentration of more than 50% in the resin without insecticide.

The preferred resin is a thermoplastic resin, especially an olefin. Polyethylene, PE, or polypropylene, PP are suitable choices, for example a matrix comprising or consisting of low-density PP is an option. Mixtures of PE and PP are options, for example mixtures of LDPE or LLDPE with HDPE, or mixtures of LDPE or LLDPE with PP. For example, the HDPE or PP can be a homopolymer or a copolymer. In some embodiments, at least 90% of the polymer is a polyethylene, for example at least 95% or even 100%. The polyethylene may be a homopolymer, copolymer, or a blend of different types of polyethylene.

One option is a blend of LLDPE and HDPE; another option a blend of LLDPE and PP. Useful ratios between LLDPE and HDPE, or LLDPE and PP, are 80:20 to 30:70, or 70:30 to 30:70 or 70:30 to 40:60 or 70:30 to 50:50 or 65 :35 to 40:60 or 65 :35 to 55:45 or 55 :45 to 45:55. By using a blend of a high density polymer, for example HDPE, and a low density polymer, for example LLDPE, the density of the resin and, thus, the migration rate can be suitably adjusted. The higher the content of the LLDPE, the faster the regeneration time due to fast migration, but the more difficult is the processing of the product, for example yarn.

On the other hand, when the content of HDPE becomes too high, Fipronil migrates at too low a speed. For example, experiments have shown that a matrix with 90% HDPE and 10% LLDPE and a density outside the above range implies a migration rate of Fipronil that is too low for practical purposes, especially mosquito nets, because the regeneration of Fipronil on the surface of the fibres of the mosquito net is not fast enough to provide a steady sufficient dose of Fipronil to knock down and kill insects, especially mosquitoes. This is so, because Fipronil is subject to loss by various factors once migrated to the surface of the matrix, and for a satisfactory knock down and kill- ing of insects, the migrations rate should be high enough in order for the regeneration to successfully compete with the loss of Fipronil.

Among loss factors are, especially, hydrolysis and disintegration by UV radiation. Inside the polymer matrix, the incorporated Fipronil is protected against hydrolysis, and UV protecting agents may also be incorporated into the matrix for protection of Fipronil against UV radiation. However, once on the surface, the protection is not apparent any more, and a substantial loss of Fipronil occurs.

Especially, in a resin blend of HDPE and LLDPE, a content of about equal amounts of HDPE and LLDPE has proven feasible.

Non-exclusive useful ranges for the ratio between HDPE and LLDPE are 70:30 to 50:50 or 55:45 to 45:55 for yarn production, especially in insecticidal nets against mosquitoes.

A useful material has been found by using LLDPE with a density in the interval of 0.88 to 0.91 g/ccm, for example with a melt flow rate of between 1.5 and 1.7 g/ 10 minutes at 190°C and 2.16 kg test load. Another useful material has been found by using HDPE with a density in the interval of 0.94 to 0.96 g/ccm, for example with a melt flow rate of between 0.7 and 0.9 g/ 10 minutes at 190°C and 2.16 kg test load. A blend of these two materials has been found advantageous. In connection with test materials for the invention, some remarks should be addressed. As already outlined above, it has been found that the density is the crucial parameter for migration of FPN. A low density is desired on the one hand, but a high concentration of LLDPE is not so good for the workability of the extruded yarns, on the other hand. A solution out of this dilemma has been found experimentally in that the density does not have a linear behaviour in dependence of the LLDPE concentration. Surprisingly, when increasing the concentration of HDPE, the density for a mixture of HDPE and LLDPE decreases instead of increasing until a concentration of 40% HDPE before increasing with increasing concentration of HDPE. Experimentally for a set of HDPE and LLDPE , the following numbers were found for the density

HDPE LLDPE Density [g/ccm]

100% 0% 0,954

50% 50% 0,901

40% 60% 0,893

30% 70% 0,892

0% 100% 0,896

This implies that a low density of a HDPE/LLDPE mixture spans over a large range of LLDPE concentration. For example, a density of less than 0.930 implies a range of LLDPE from 25% to 100%, whereas a density of less than 0.920 implies a range of LLPDE from 30% to 100% for these materials.

Advantageously, Fipronil is provided in the resin at a bulk concentration of 0.1-20 g per kg resin or 2-10 g/kg or 3-8 g/kg or 4-6g/kg. Experimentally, it was found in a matrix with LLDPE and HDPE, that for a concentration of 0.5% Fipronil (FPN) the density of a 50:50 LLDPE: HDPE blend was lower than the density of LLDPE alone. This is utmost surprising. For example, for a 50:50 blend of HDPE having a density of 0.954 g/ccm and LLDPE having a density of 0.896 g/ccm, addition of 0.5% Fipronil resulted in an insecticidal resin having a density of 0.893 g/ccm, which is even lower than the density of pure LLDPE despite the content of the heavier HDPE and the content of the heavier Fipronil. This effect is believed to apply for Fipronil-concentrations 0.2%-l%, especially 0.3% to 0.8%. In the experi- ment, the resin with Fipronil had a density of Less than 0.920 g/ccm also at LLDPE :HDPE ratios of 60:40 and 70:30.

As a result, independent from the invention of the insecticide-free resin according to the parameters above, the purpose of good migration properties of Fipronil and the purpose of providing a suitable carrier for Fipronil with a long lasting insecticidal effect on insects, is also achieved by a resin containing LLDPE and HDPE in a ratio of 70:30 to 30:70 or 60:40 to 40:60 and 0.2% to 1% Fipronil, for example 0.3% to 0.8% , wherein the resin including the Fipronil has a density of 0.890-0.930 g/ccm. Alternatively, the resin including 0.2%-l%, for example 0.3%> to 0.8%>, Fipronil has a density of 0.890-0.920 g/ccm. Alternatively, the content of the Fipronil for the LLDPE/HDPE blend is 0.4-0.6%. However, optionally these parameters can be combined with the above parameters for the resin without Fipronil.

Examples of useful products according to the invention are films, tarpaulins, fibres, woven fabrics, or non woven fabrics. The fabric may be woven or non-woven with a yarn that is melt-extruded. One application is fibres for mosquito nets.

Interesting in connection with the resin above are fabrics made from flat yarns where the yarns have been cut in slices from thin polymer sheets. The fabrics may be woven or non- woven. For example, such flat yarn has a thickness of 0.015 to 0.065 mm, or 0.025 to 0.50 mm or 0.030 to 0.040 mm. Examples of the widths are 1-6 mm, 2-5 mm, or 3-4 mm.

For such thin yarns, the general expectation in the prior art is that the polymer has to contain dominantly HDPE with a high weight density of the resin in order to slow down the migration to such an extent that the yarn is insecticidally long lasting. Surprisingly, however, is has turned out that in insecticidal yarns of this type, the density has to be low by using a relatively large amount of LLDPE, in some cases even domi- nantly LLDPE. The use of a resin weight density of 0.890 to 0.930 g/ccm or 0.890 to 0.920 g/ccm is surprising for insecticidally long lasting flat, thin yarns of the above stated dimensions. A preferred bulk concentration is between 0.1-20 g Fipronil per kg resin or 1-10 g/kg or 3-8g/kg or 4-6 g/kg.

In addition to Fipronil, it has been found advantageous to include a synergist in the resin, especially piperonyl butoxide (PBO), along with the insecticide, for example at a concentration of between 1-lOg/kg, 2-5g/kg, or 3-4 g/kg. Useful combinations are 0.1- 20 g Fipronil and 1-10 g or 2-5 g PBO per kg resin, 1-10 g/kg or 4-6 g/kg Fipronil and 2-5g PBO per kg resin, or 1-10 g/kg or 4-6 g/kg Fipronil and 3-4 g PBO per kg resin.

For a resin in the form of yarns in a fabric, the surface area concentration depends on the thickness of the fabric, but ranges optimally from 180-1500 mg/m2, for example from 400-1000 mg/m2. The surface concentration can be maintained long lasting due to controlled migration of the Fipronil to the surface.

In some embodiments, the product is a flat yarn with a thickness of 0.015 to 0.065 mm and a width of 1 to 6 mm and the resin comprises 0.1-20 g Fipronil per kg polymer, for example 2 to 10 or 3 to 8 g/kg, corresponding to 0.2% to 1% or 0.3%> to 0.8%>, all percentages in weight percentage. For example, at least 90% of the polymer is a blend of HDPE and LLDPE. In some embodiments, an insecticidal fabric is provided with a flat yarn as described above, for example by knitting or weaving, and the migration rate of the Fipronil in the resin is adjusted for providing a surface concentration of 180-1500 mg Fipronil per m² of the fabric. For example, the resin comprises LLDPE and HDPE at a ratio of between 80:20 and 30:70 or 70:30 and 30:70, wherein the resin without insecticide has a density of 0.890 to 0.930 g/ccm, wherein the LLDPE has a density in the interval of 0.88 to 0.91 g/ccm and a melt flow rate of between 1.5 and 1.7 g/ 10 minutes at 190°C and 2.16 kg test load, wherein Fipronil is provided at a bulk concentration of 0.1-20 g per kg resin or 3-8 g per kg resin. Optionally, the resin comprises PBO at a concentration of 1-10 or 3-4 g per kg resin. As already mentioned above, if the content of LLDPE is high in the resin, the elongation becomes high, which makes weaving or knitting difficult with such a yarn. In cases, where an optimum migration and long-lasting efficacy of the product requires a high content of LLDPE in the resin, for example 60% or even 80%, and further production steps are required, for example weaving or knitting, the following solution is possible. In this case, a first filament with Fipronil and a resin containing dominantly LLDPE is combined into a single yarn, for example by plying with a second filament made of a stronger material, in order to achieve sufficient strength. For example, the stronger material is HDPE or PP or a blend of polymers with dominantly HDPE or PP. Alternatively, the stronger material may comprise polyester, where the term polyester includes the type of polyethylene terephtalate.

For example, this stronger filament does not contain insecticides but only has a stabilising task for the combined yarn. Alternatively, the second filament contains a further insecticide or synergist or both. In contrast to the above mentioned International Patent Application WO2010/046348, disclosing a combination of yarns or filaments containing pyrethroids and Fipronil, the Fipronil filament according to the invention has a low density, for example contains dominantly LLDPE, whereas the Fipronil filament in WO2010/046348 has a high density as it contains dominantly HDPE, especially, at least 6 times more HDPE than LLDPE.

Although Fipronil in principle may be used for bednets, this is not optimum due to the risk for skin irritation by Fipronil, unless Fipronil is only used in the top part of a bed- net, which is typically not touched. However, in this light, it is an advantage to find other ways for dispensing Fipronil. As it is explained in greater detail in International patent application WO 2009/059607, a mosquito will find a place to rest after a blood meal, typically on a wall in a house. Therefore, it is an advantage if the wall is covered at least partly by a product with an insecticidal resin as explained above, for example in the form of a wall lining, which typically is a fabric with round or flat yarns, which is woven or non- woven. As also explained in the same International patent application, in many African countries, dwellings comprises huts with walls, roof and a space between the upper edge of the walls and the roof, typically a space with a height of 0.2 m to 0.4 m. The invention also is useful for woven or non-woven fabrics or films or tarpaulins covering these openings in order to prevent insects entering the huts. Especially for such wall coverings or coverings for openings, fabrics with flat yarn, as described above, are useful.

In some embodiments, the content of the ethylene is at least 80% or 90% by weight of the resin. The remaining part may be constituted by the insecticide or insecticides and additives of various kinds, for example other polymers, synergists, UV protecting agents, preservatives, anti-hydrolysis agents, detergents, fillers, impact modifiers, anti- fogging agents, blowing agents, clarifiers, nucleating agents, coupling agents, conductivity-enhancing agents to prevent static electricity, stabilizers such as anti-oxidants, carbon and oxygen radical scavengers and peroxide decomposing agents and the like, flame retardants, mould release agents, optical brighteners, spreading agents, antiblocking agents, anti-migrating agents, migration promoters, foam-forming agents, anti- soiling agents, antifouling agents, thickeners, wetting agents, plasticizers adhesive or anti-adhesive agents, fragrance, pigments, and dyestuffs.

The products is useful as a barrier against insects for protecting crops, animals, or humans.

Non exclusive applications include nets in general, curtains, carpeting and window screens, door screens, tents, horse blankets, fabrics or nettings for packages, wrapping sacks, construction materials, furniture, leathers, electric wires and cables.

Also within the field of agriculture, for example crop protection, and for protection of animals, the products are useful. Included are mulch films and nets or films for green- houses and animal sheds and stalls. Other uses include pig pens, and fences for cattle, fowl, and horses. For example, the product can be used as a fencing along or around an agricultural field for preventing insects to enter the field or as a fencing along or around a field with animals for preventing insects to reach animals on the field. An example is given in international patent application WO0300382. The fencing could be in the form is an up- right standing net along or surrounding an open air area. Alternatively, the product may be used to cover crops, for example as a film or net. The product may also be used for greenhouses, for example in the form of nets or films.

Further special applications in connection with the invention are as,

- pesticidal blanket, for example as disclosed in WO03055307,

- air cleaning canopy, for example as disclosed in WO2006024304,

- tarpaulins, for example as disclosed in WO 03/063587.

Although, the primary purpose of the invention is to protect against mosquitoes, it also includes control and/or to combat a variety of pests, such as ticks, cockroaches, bed bugs, mites, fleas, lice, leeches, houseflies, termites, ants, moths, spiders, grasshoppers, crickets, silverfish, aphids, thrips, whiteflies, midges, beetles and other flying and crawling insects. For stated intervals of parameter values, the end points of the intervals are, optionally, included in the interval.

Although the resin above is primarily useful for Fipronil, it may also be employed by other insecticides, especially pyrazols, other phenyl pyrazoles, and neonicotinoids, for example Dinotefuran. Further, it may be useful for pyrethroids, organophoshates, carbamates, pyrroles, and nicotinoids, the classes including Deltamethrin, Permethrin, and Chlorphenapyr. This list of insecticides is not exhaustive. Such a resin is useful for long lasting products with migration of incorporated insecticides from the bulk of the resin to the surface of the resin.

In a more insecticidally generalised case, a resin may be defined as comprising a linear low density polyethylene, LLDPE, and a high density polyethylene, HDPE, and an insecticide, for example Dinotefuran, distributed throughout the resin by incorporation, wherein the ratio between the LLDPE and the HDPE is between 70:30 and 30:70, and wherein the resin without insecticide has a density of 0.890 to 0.930 g/ccm. Alternatively, the resin comprises a blend of LLDPE and PP with a density of 0.890 to 0.930 g/ccm.

The additional parameters as stated above apply equally well to this generalised case, especially the following optional aspects that

- the density is 0.890 to 0.930 g/ccm;

- the ratio between LLDPE and HDPE or LLDPE and PP is 80:20 to 30:70 or 70:30 to 30:70 or 70:30 to 40:60 or 70:30 to 50:50 or 65:35 to 40:60 or 65:35 to 55 :45 or

55:45 to 45 :55;

- the LLDPE has a density in the interval of 0.88 to 0.91 g/ccm, for example with a melt flow rate of 1.5 to 1.7 g/ 10 minutes at 190°C and 2.16 kg test load;

- the HDPE has a density in the interval of 0.94 to 0.96 g/ccm, for example with a melt flow rate of between 0.7 and 0.9 g/ 10 minutes at 190°C and 2.16 kg test load;

- the resin contains PBO at a concentration per kg resin of between 1-lOg/kg or 1-10 g/kg or 4-6 g/kg;

- 90% of the polymer is polyethylene;

Each of the aspects can be employed singular in addition to the generalised case, or the aspects may be employed in various combinations, for example as defined by the present claims for Fipronil.

For example, a generalised product may comprise the following aspects: the resin comprises LLDPE and HDPE or PP at a ratio of 80:20 and 30:70, wherein the resin with- out insecticide has a density of 0.890 to 0.930 g/ccm, wherein the LLDPE has a density in the interval of 0.88 to 0.91 g/ccm and, optionally, a melt flow rate of between 1.5 and 1.7 g/ 10 minutes at 190°C and 2.16 kg test load.

The generalised products with the various options for insecticides, for example Dinote- furan, apply also to the above mentioned flat yarns, mosquito nets, and wall covers and the different other uses listed above.

Claims

1. A product with a thermoplastic polymer resin containing Fipronil distributed throughout the resin by incorporation, wherein the resin without insecticide has a den- sity of 0.890 to 0.930 g/ccm.

2. A product according to claim 1, wherein the density is 0.890 to 0.920 g/ccm.

3. A product according to claim 1 or 2, wherein the resin comprises a polyolefm.

4. A product according to claim 3, wherein at least 90% of the resin is polyethylene.

5. A product according to claim 4, wherein the polyethylene is a blend of linear low density polyethylene, LLDPE, and high density polyethylene, HDPE, with a ratio be- tween the LLDPE and the HDPE between 80:20 and 30:70.

6. A product according to claim 5, wherein the ratio between the LLDPE and the HDPE is 65:35 to 40:60. 7. A product according to claim 5 or 6, wherein the LLDPE has a density in the interval of 0.88 to 0.91 g/ccm and a melt flow rate of 1.5 to 1.

7 g/ 10 minutes at 190°C and 2.16 kg test load.

8. A product according to claim 3, wherein the resin comprises a blend of linear low density polyethylene, LLDPE, and polypropylene, PP.

9. A product according to any preceding claim, wherein Fipronil is provided in the resin at a bulk concentration of 2-10 g per kg resin.

10. A product according to claim 5, wherein the resin comprises at least 90% polyethylene being a blend of LLDPE and HDPE at a ratio of 80:20 and 40:60, wherein the resin without insecticide has a density of 0890 to 0.930 g/ccm, wherein the LLDPE has a density in the interval of 0.88 to 0.91 g/ccm and a melt flow rate of between 1.5 and 1.7 g/10 minutes at 190°C and 2.16 kg test load, wherein Fipronil is provided at a bulk concentration of 2-10 g per kg resin.

11. A product according to claim 5, wherein the blend has an LLDPE:HDPE ratio of 70:30 to 40:60, and the resin including the Fipronil has a density of less than 0.920 ccm.

12. A product according to any preceding claim in the form of a ply yarn with a first filament in plied combination with a second filament, the first filament comprising a resin with Fipronil and dominantly LLDPE, and wherein the second filament is a stabilising olefin filament with dominantly HDPE or PP.

13. A product according to claim 12, wherein the second filament is free from insecti- cide.

14. A product according to claim 12 or 13, wherein the second filament contains a synergist.

15. A product according to any preceding claim, wherein the resin also contains a synergist with synergistic insecticidal action in combination with Fipronil.

16. A product according to claim 15, wherein the resin contain PBO at a concentration of between 1-lOg/kg.

17. A product according to any preceding claims, wherein the product is at least one from the group of a woven fabric, a non woven fabric, a textile, and a net.

18. A product according to preceding claims, wherein the product is a bednet.

19. A product according to any one of the claim 1-16, wherein the product is a flat yarn with a thickness of 0.015 to 0.065 mm.

20. A product according to claim 19, wherein the thickness is 0.025 to 0.050 mm.

21. A product according to claim 19 or 20, wherein the product is a flat yarn with a width of 1 to 6 mm.

22. A product according to claim 21, wherein the width is 2 to 5 mm.

23. A product according to anyone of the claims 19-22, wherein the yarn is part of a woven fabric.

24. A product according to anyone of the claims 19-22, wherein the yarn is part of a non- woven fabric.

25. A product according to claim 23 or 24 in combination with a house, wherein the fabric is a cover for at least part of a surface of a wall in the house.

26. A product according to claim 23 or 24 in combination with a house, wherein the fabric is part of a cover of an opening between an upper edge of a wall in the house and a roof above the wall.

27. A product according to anyone of the claims 1-15, wherein the product is a flat yarn with a thickness of 0.015 to 0.065 mm and a width of 1 to 6 mm and wherein the resin comprises 0.1-20 g Fipronil per kg polymer and 90% of the resin is polyethylene comprising more than 50% LLDPE.

28. A method for protecting crops, animals, or humans against insects by providing a product according to anyone of the claims 1-27 as a barrier against insects.

29. A method according to claim 28, wherein the method comprises providing the product in the form of an upright standing net along or around an agricultural field or field with animals preventing insects to enter the field.

30. A method according to claim 29, wherein the method comprises providing the product in the form of a net or film in a greenhouse protecting plants in the greenhouse against insects.