CZ309702B6 - Insecticide for protecting wood against pests - Google Patents

Abstract

An insecticidal agent of at least one solid fibre carrier attached to at least one wall of the textile carrier by lamination, the fibre carrier comprises nanofibres containing at least one synthetic polymer selected from the group of polyamide, polyurethane, polyvinylidene fluoride, polyvinylidene difluoride, cellulose acetate, polylactide, polycaprolactone, polyvinyl butyral, polylactic acid or a mixture of them and at least one active substance, which is an imagocide.

Description

Insecticidal agent to protect wood against pests

Field of technology

The invention relates to an insecticidal textile composition containing at least one polymeric nanofibrous layer as a carrier of a substance effective in killing wood-destroying and bark-eating insects attacking deciduous and coniferous stands.

Current state of the art

Different procedures and active substances can be used to control wood-rotting and bark-destroying insects in forest stands. The oldest method is the use of poisoned traps. In the 1970s, aggregating pheromones to attract insects to the traps began to be applied to the traps. Debarking the infested wood before reaching the adult development stage is also effective. Although both of these methods are effective, they are insufficient in times of calamity.

Newer methods use water-applied insecticides to sprinkle landfills or store wood in water with insecticides. These methods are economically demanding and also represent a significant ecological risk related to the penetration of insecticides into the soil or the poisoning of small forest animals.

Recently, Storanet insecticidal nets have appeared on the market, which kill pests in the adult development stage by contact. This net can be used to protect landfills of uninfested wood, to rehabilitate infested wood, and at the same time as poison traps. This solution is described in WO 2010012671. The described net is impregnated with an insecticide, essentially it is covered from all sides, which is disadvantageous when handling the net for the operator who is exposed to the toxic effects of the insecticide substance. The net also kills other forest insects that land on the surface of the net. To ensure functionality, it is impregnated with a high dose of insecticides, the production process produces a large amount of toxic waste. The workers who apply it must be trained, equipped with protective equipment, and the total time of installing the network is therefore long. The disadvantage is also the low resistance of the net, it often tears and does not have stable properties in the long term of the season.

In recent years, fumigation technology has been used, which uses the preparation ethanenitrile (EDN) to clean landfills of infested wood. EDN is a fumigant, i.e. a volatile pesticide used in a gaseous state to destroy diseases and pests. This method is currently permitted with an exception and, in terms of cost, is particularly suitable for large wood dumps (minimum 350 m ³ ), another disadvantage of this method is the fact that it can only be performed by a specialized company, as it is a volatile, toxic substance. The applicability of this method is very limited to large landfills and the dates of free capacities of specialized companies that have the appropriate permits to handle toxic and hazardous waste. However, a fundamental problem is the possibility of contamination of the soil and, consequently, of water sources in the locality.

Another method of remediation of infested wood is the MARCATA technology, which combines the application of insecticide by spraying on the edge surface and covering the treated landfill with a non-woven fabric. This technology is protected by the utility model UV 32889.

The practical disadvantage of this technology is the fact that the insecticide applied in this way loses its effectiveness after 4 to 6 weeks, and some of the adults developed from the larvae remain under the tarpaulin after this period and manage to find an escape route after a certain time.

Technologies for the production of nanofibrous structures (layers) enable the production of nanofibrous layers on an industrial scale. Since the beginning of the 21st century, they have been introduced into industrial production in the field of production of filter media, functional textile materials, separation membranes.

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In the areas of technical and medical applications, these structures are used as carriers of active active substances, for example antimicrobial substances, pharmacologically active substances, etc.

The essence of the invention

The aforementioned disadvantages of the state of the art are overcome by an insecticidal composition, the essence of which is that it is in the form of at least one solid fiber carrier, which includes nanofibers containing at least one synthetic polymer selected from the group containing polyamide, polyurethane, polyvinylidene fluoride, polyvinylidene difluoride (PVDF), cellulose acetate, polylactide , polycaprolactone, polyvinyl butyral (PVB), polylactic acid (PLA) or their mixture and at least one active substance or their mixture; wherein the fibrous carrier is attached to at least one wall of the textile carrier by lamination. Synthetic polymer means any type of organic polymer from which nanofibers can be produced using known technologies, preferably electrospinning.

The connection between the wall of the fiber carrier and the (inner) wall of the textile carrier is ensured either by the presence of bicomponent fibers in the textile carrier, which are melted during lamination and enable the connection between the walls and/or by means of an adhesive that is applied to the textile carrier in the area before lamination, or in the form of a point grid or sieve.

Nanofibers can be produced using the principle of electrostatic spinning from a polymer spinning solution with a concentration of 10 to 18% by weight, preferably 12 to 14% by weight. of synthetic polymer per total solution volume.

The active ingredient is an insecticidal substance that acts on adult bark beetles in a contact manner. These are preferably imagocides. The active substance can be at least one insecticide, an imagocide, which is selected from the group containing synthetic or natural pyrethroids, preferably containing cypermethrin (cyano(3-phenoxyphenyl) methyl ester of 3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropanecarboxylic acid) , zeta-cypermethrin ((1-(3,5-dichloro-2,4-difluorophenyl)-3-(2,6difluorobenzoyl)urea), alpha-cypermethrin ((1R)-cis-(alphaS)-cypermethrin), cyfluthrin ([(R )cyano-[4-fluoro-3-(phenoxy)phenyl]methyl](1 R ,3 R )-3-(2,2-dichlorothenyl)-2,2-dimethylcyclopropane-1-carboxylate) , deltamethrin ([(S)-cyano(3-phenoxyphenyl)methyl]-( 1R ,3R )-3-(2,2dibromothenyl)-2,2-dimethylcyclopropane-1-carboxylate), ethofenprox (1-ethoxy-4 -[2-methyl-1 ([3-(phenoxy)phenyl]methoxy)propan-2-yl]benzene), permethrin ((3-phenoxyphenyl)2,2-dimethyl-3-(2,2-dichlorovinyl)methyl ester )-cyclopropanecarboxylic), bifenthrin (2-methyl-3phenylphenyl)methyl(1S,3S)-3-[(Z)-2-chloro-3,3,3-trifluoroprop-1-enyl]-2,2- dimethylcyclopropane-1carboxylate), chlorfenapyr (4-bromo-2-(4-chlorophenyl)-1-ethoxymethyl-5-trifluoromethyl-1H-pyrrole-3-carbonitrile) and fipronil (5-amino-1-[2,6-dichloro -4-(trifluoromethyl)phenyl]-4-[( R S )-trifluoromethanesulfmyl]-1H-pyrazole-3-carbonitrile) or mixtures thereof. The best are alpha-cypermethrin, zeta-cypermethrin, cypermethrin.

Furthermore, it can also be a pheromone, preferably a synthetic pheromone selected from the group containing (S)cis-verbenol (4,6,6-trimethylbicyclo[3.1.1]hept-3-en-2-ol), ipsdienol ((4S) -2-methyl-6-methylideneocta-2,7-dien-4-ol) or a mixture thereof.

The active substances contained in the nanofibers of the fiber carrier according to the invention act against pests selected from the group containing pests from the genus: bark beetles, carp, woodpeckers.

The active ingredient is in the nanofibers, or fiber carrier according to the invention applied during their preparation by electrospinning from the spinning solution to which it is dissolved, therefore it is contained in the entire volume of nanofibers. Or it can be additionally applied to the nanofibrous carrier by impregnation, for example by spraying, wetting or spraying. After impregnation, the active substance is only on the surface of the fibers.

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The diameters of the nanofibers in the fiber carrier according to the invention are in the range of 90 to 450 nm, preferably 120 to 150 nm.

The insecticidal textile composition according to the invention serves as a contact layer for contact with adult pests in order to kill them.

The solid fiber carrier according to the invention is a layer of nanofibers as described above. If the composition according to the invention contains two or more fiber carriers, these are arranged on top of each other in layers and the active substance is contained in the nanofibers of any of the fiber carriers. Advantageously, the active substance is contained in the nanofibers of the contact fiber carrier, which represents the outer, contact side of the agent according to the invention. A contact fiber carrier is a fiber carrier that comes into contact with pests after use. The fibrous carrier of the composition according to the invention therefore has an extremely high specific surface area. This can be used as a carrier of the active substance. By choosing a synthetic polymer, it is possible to influence the stability of the fibrous carrier from a very quickly soluble to a long-term stable carrier from which the active substances are not released. A variant of degradable synthetic polymers is the polymer Polycaprolactone (PCL) or polylactic acid (PLA). Non-degradable polymers include polyamide. Before spinning, the polymers are dissolved in acids, for example in a mixture of acetic acid/formic acid in a ratio of 2:1.

The long-term stability of the solid fiber carrier according to the invention in the outdoor environment is at least 6 to 7 months (at least for one season) and significantly lower concentrations of the toxic/active substance are advantageous parameters of the invention, which can only be achieved by using the agent according to the invention.

The content of the active substance (preferably zeta cypermethrin) in g per m ² of the fibrous carrier of the insecticidal agent according to the invention is 0.001 to 0.05 g/m ² , preferably 0.005 to 0.02 g/m ² , more preferably 0.01 to 0.02 g/m ² .

The basis weight of the fibrous carrier in the composition according to the invention is 0.1 to 5.0 g/m ² , preferably from 0.2 to 1.0 g/m ² .

A layer of polyamide 6 nanofibers with an area weight of 0.2 g/m ² , which contained zeta cypermethrin in an amount of 0.002 g/m ² , proved to be an already effective layer (mortality of pest individuals occurred 4 hours after the first contact). A layer with an area weight of 0.2 g/m ² containing zeta cypermethrin at a concentration of 0.01 g/m ² was highly effective, in which the mortality of the pest individuals occurred within 10 to 60 minutes from the first contact. The fibrous carrier according to the invention of the stated surface weight (0.2 g/m ² ) is in itself a mechanically unstable, unmanipulatable structure, for the production of which by the electrospinning method the substrate on which it is applied is necessary. This substrate can also be a textile carrier, which is part of the insecticidal textile composition according to the invention. Sufficient mechanical reinforcement, i.e. the textile carrier in the preparation according to the invention, are textiles with a surface weight of from 20 g/m ² to 120 g/m ² , preferably 50 to 60 g/m ² . The textile carrier is selected from the group containing polyester fabrics, rasp fabrics, geotextiles, non-woven fabrics, preferably polypropylene (PP) spunbond fabrics with a UV-stabilized structure, polyamide non-woven fabrics.

The fiber carrier can be additionally applied to the textile carrier during the process of transferring the fiber carrier from the substrate used for production to a suitable textile carrier.

The functionalization of the nanofibers of the fiber carrier with an insecticidal substance is performed by adding an active substance, for example zeta cypermethrin, to the polymer solution, from which the nanofiber structure (carrier, layer) is subsequently produced by the electrospinning process. The active substance, for example zeta cypermethrin can be added to the spinning solution in the form of a solution (variants are given in points 1 and 2 below in the examples where its concentration in the added solution is in the range of 20 to

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100 g/liter), or this substance can be added directly to the polymer solution, whereby the resulting concentration of the active substance, for example alpha cypermethrin, in the spinning solution polymerizes in the range of 0.001 to 1.5% w/v. to the total volume of the spinning solution.

The combination of a nanofiber carrier and a textile carrier in the insecticidal textile agent according to the invention ensures mechanical resistance and handling of the agent.

The resulting composite (composition according to the invention) is preferably in the form of a tarpaulin intended for covering wood, more preferably intended for covering freshly cut wood in order to protect it from being attacked by bark beetles or to cover attacked wood from the excursion of adult bark beetles in order to reduce the pest situation in forest stands. When an adult comes in contact with the outer surface of the fibrous carrier of the agent according to the invention, it will be killed. The product according to the invention ensures highly effective extermination of pests in the adult development stage. This contributes to the protection of healthy forest cover.

Advantageously, the device according to the invention is provided on one side of the textile carrier with a contact fiber carrier. This arrangement of the product according to the invention is suitable for the production of sails, which can be applied to protect landfills of uninfested wood, to rehabilitate infested wood and at the same time as poison traps. Handling tarpaulins in an outdoor environment when covering a landfill places demands on the mechanical properties of the product according to the invention, resistance to weather conditions.

By the fact that the contact fiber carrier is only on one side of the product according to the invention, a high level of safety is ensured for the work of application workers when handling the product. Unlike spraying, the composition according to the invention can be applied near water sources. There is no water contamination and no fish kills. No other insects are killed.

Between the textile carrier and the fiber carrier, it is necessary to ensure the necessary adhesion (cohesion) for subsequent handling. This can be ensured by various gluing technologies.

Among the simplest are the application of different types of adhesives (powder or hot-melt adhesive, hot-melt mesh (bonding in the form of a mesh)) or the use of bicomponent fibers in a textile carrier, which are melted in the subsequent lamination process (melting of one component of the fibers) and the pressure creates a layer of the textile carrier and the fiber carrier layer connected. An example of a bicomponent fiber is a polyester fiber, the core of which is fusible only at temperatures above 190 °C, but the sheath of the fiber melts at temperatures above 110 °C.

The textile carrier is provided with an adhesive on the wall adjacent to the fiber carrier, which is selected from the group containing powder adhesive, hot-melt adhesive, hot-melt mesh.

The contact outer side of the fiber carrier must be mechanically strengthened to prevent abrasion during handling and application of the sheet. Therefore, a covering layer, preferably a fusible mesh based on low-melting polyethylene copolymers, is preferably attached to the contact outer side of the fiber carrier. Strengthening can be done by tennobonding technology, ultrasonic bonding.

The combination of gluing the fiber carrier to the textile carrier and at the same time strengthening the outer contact side of the fiber carrier is hot melt bonding technology, which can be used when transferring the fiber carrier from the substrate to the textile carrier. For this technology, the limit value is an area weight of 0.1 g/m ² of the fiber carrier, carriers with a lower area weight are not transferable in the industrial process of continuous production.

Another variant of mechanical strengthening, or protection of the surface of the fiber carrier from abrasion, is the application of low-melting nets on the surface of the fiber carrier. The application of low-melting nets will strengthen and protect the surface from delamination and abrasion, while also removing the contact area needed to kill pests. Variants of fusible nets are glue nets based on polyamides (Spunfab PA) (co- 4 CZ 309702 B6 polyamide) or on the basis of low-melting polyethylene copolymers LDPE/HDPE/LDPE fabric made from LDPE/HDPE/LDPE film.

The advantageous arrangement of the layers in the composition according to the invention is that at least one side of the textile carrier is provided with at least one fiber carrier, to which at least one covering layer in the form of a low-melting net adheres from the other (outer) side, while the contact surfaces between the textile carrier and the fiber carrier are preferably provided with an adhesive and the outer side of the fiber carrier is reinforced with a low-melting net. All layers of the composition according to the invention are preferably attached to each other by means of lamination. It is practically possible to use all kinds of textile lamination technologies using adhesives or technology using heat (thermobonding).

Clarification of drawings

Giant. 1 Fibrous carrier made of PA6 nanofibers with an area weight of 1.0 g/m ² , containing zetacypermethrin.

Giant. 2 Fibrous carrier made of PA6 nanofibers with an area weight of 0.23 g/m ² , containing cypermethrin, in the background a fiber from a non-woven fabric substrate

Examples of implementation of the invention

Preparations containing these layers:

1) Non-woven polypropylene fabric (PP SB) stabilized against UV radiation with an area weight of 50 g/m ² , a layer of powder glue EVA T06 (melting glue based on ethylene-vinyl-acetate) is applied (poured and fused) to this carrier (granulation 80 to 200 pm) with a basis weight of 5 g/m ² . A fiber carrier made of the polymer polyamide 6 (PA6) (the basic type of extruded polyamide) with an area weight of 0.2 g/m ² containing the addition of zeta cypermethrin with a content of 0.001 g/m ² is applied to the non-woven fabric with the application of powder adhesive (Fig. 1) . To the spinning solution containing PA6 with a concentration of 14% by weight. Fury 10 EW containing zeta-cypermethrin (1-(3,5dichloro-2,4-difluorophenyl)-3-(2,6-difluorobenzoyl)urea) (100 g/1) was added. The diameters of the nanofibers in the resulting carrier range from 90 to 250 nm (optimally 120 to 150 nm), depending on the concentration of the polymer solution and the conditions of preparation of the fiber carrier. LDPE/HDPE/LDPE fabric is laminated to the fiber carrier.

2) Polyester non-woven fabric with an area weight of 60 g/m ² , a layer of EVA T06 powder adhesive (granulation 80 to 200 pm) with an area weight of 5 g/m ² is applied (poured and fused) to this carrier. A fiber carrier made of polymer PA6 with an area weight of 0.2 g/m ² containing an addition of cypermethrin with a content of 0.001 g/m ² is applied to the non-woven fabric with the application of powder adhesive (Fig. 2). Into the spinning solution containing PA6 with a concentration of 14% by weight. Nurelle D containing the active substance cypermethrin (50 g/1) was added. The diameters of the nanofibers in the structure range from 90 to 250 nm (optimally 120 to 150 nm), depending on the concentration of the polymer solution and the preparation conditions of the nanofiber structure. LDPE/HDPE/LDPE fabric is laminated to the fiber carrier.

Preparation procedure:

1a) Into the polymer solution of polymer PA6, 14 wt.% concentration of the polymer in the solvent system acetic acid/formic acid in a ratio of 2:1, a solution containing an insecticide is added to form a spinning solution. This is a Fury 10 EW solution containing zeta-cypermethrin (100 g/1). The insecticide solution is added to the polymer solution at a concentration of 0.05 to 1.0% by weight. (optimally 0.5% by weight).

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1b) Into the polymer solution of polymer PA6, 14 wt.% concentration of the polymer in the solvent system acetic acid/formic acid in a ratio of 2:1, a solution containing an insecticide is added to form a spinning solution. This is a Nurelle D solution containing the active substance cypermethrin (50 g/1). The insecticide solution is added to the polymer solution at a concentration of 0.075 to 1.5% by weight. (optimally 0.075% by weight).

1c) Into the polymer solution of polymer PA6, 14 wt.% concentration of the polymer in the solvent system acetic acid/formic acid in a ratio of 2:1, cypermethrin is added in an amount of 0.01 to 1.0 wt.%. (g/liter) of the solution (optimally 0.1% by weight (g/liter).

2) PP SB UV stabilized with an area weight of 50 g/m ² is used as a textile carrier for the application of the fiber carrier, another variant is the use of Novolin 80 gsm polyester non-woven fabric (100% polyester with a weight of 80 g/m ² ).

3) a layer of EVA T06 powder glue (granulation 80 to 200 pm) with a surface weight of 3 to 10 g/m ² is applied to the textile carrier and is melted onto the textile carrier at a temperature of 110 to 120 °C (optimum application of 5 g/m ² ).

4) A fiber carrier made of a spinning solution is applied to the textile carrier by the electrospinning process (NanospiderTM technology or other electrospinning technology) (see point 1). The fibrous carrier has an area weight of 0.1 to 5.0 g/m ² (a layer of 0.05 g/m ² is sufficient to achieve even a partial effect).

5) LDPE/HDPE/LDPE fabric is used to stabilize the fiber carrier on the outside (contact side).

The selected EVA T06 powder adhesive has a low melting point of 100 to 120 °C, as does the LDPE/HDPE/LDPE stabilizing fabric. At the same time, this temperature is lower than the melting temperature of the chosen substrate (PP SB or PES non-woven fabric). Thanks to this combination, the structure of the textile carrier and fiber carrier will not be destroyed when all layers are connected.

6) Connection of all layers is ensured in one step when passing through the laminating machine. The lamination temperature ranges from 100 to 120 °C, optimally 110 °C. The connection occurs through a combination of temperature and pressure. It is practically possible to use any lamination technology working on this principle.

7) It is possible to make sails of any size from the produced material (textile wound on rolls with a width of 1.6 to 2.4 meters).

Claims (12)

1. An insecticidal agent intended to protect wood from wood-destroying and bark-boring insects, characterized in that it is in the form of at least one solid fiber carrier attached to at least one wall of the textile carrier by lamination, wherein the fiber carrier includes nanofibers containing at least one synthetic polymer selected from the group containing polyamide, polyurethane, polyvinylidene fluoride, polyvinylidene difluoride, cellulose acetate, polylactide, polycaprolactone, polyvinyl butyral, polylactic acid or a mixture thereof and at least one active substance, which is an imagocide, which is selected from the group containing cypermethrin, zeta-cypermethrin, alpha-cypermethrin, cyfluthrin, deltamethrin, ethofenprox, permethrin, bifenthiin, chlorfenapyr and fipronil or mixtures thereof, preferably alpha-cypermethrin, zeta-cypermethrin, cypermethrin, or mixtures thereof. 2. An insecticidal agent according to claim 1, characterized in that it further contains a pheromone, preferably a synthetic pheromone selected from the group containing (S)-cis-verbenol, ipsdienol or a mixture thereof. 3. An insecticidal agent according to claim 1 or claim 2, characterized in that the nanofibers of at least one solid fiber carrier contain the active substance in the entire volume. 4. An insecticidal agent according to any one of claims 1 to 3, characterized in that the diameters of the nanofibers in the fiber carrier are in the range of 90 to 450 nm, preferably 120 to 150 nm. 5. An insecticidal composition according to any one of claims 1 to 4, characterized in that the content of the active substance in the fibrous carrier is 0.001 to 0.05 g/m ² , preferably 0.005 to 0.02 g/m ² , more preferably 0.01 up to 0.02 g/m ² . 6. An insecticidal agent according to any one of claims 1 to 5, characterized in that the surface weight of the fibrous carrier is 0.1 to 5.0 g/m ² g/m ² , preferably from 0.2 to 1.0 g/ m ² . 7. An insecticidal agent according to any one of claims 1 to 6, characterized in that the textile carrier is textiles with an area weight of 20 to 120 g/m ² , preferably 50 to 60 g/m ² . 8. An insecticidal agent according to any one of claims 1 to 7, characterized in that the textile carrier is selected from the group containing polyester fabrics, rasp fabrics, geotextiles, non-woven fabrics, preferably polypropylene PP spunbond fabrics with a UV-stabilized structure, polyamide non-woven fabrics. 9. An insecticidal composition according to any one of claims 1 to 8, characterized in that the textile carrier is provided with an adhesive on the wall adjacent to the fiber carrier, which is selected from the group containing powder adhesive, hot-melt adhesive, hot-melt mesh. 10. An insecticidal agent according to any one of claims 1 to 9, characterized in that a cover layer, preferably a fusible network based on low-melting polyethylene copolymers, is attached to the contact outer side of the fibrous carrier. 11. An insecticidal composition according to claim 10, characterized in that the fiber carrier, the textile carrier and the cover layer are connected by lamination. 12. An insecticidal composition according to any one of claims 1 to 11, characterized in that it is in the form of a tarpaulin intended for covering wood.