FI114146B - Insect repellent tent fabric - has a coating contg. polymeric binder, flame retardant chemicals, water repellent chemicals and permethrin - Google Patents

Abstract

A coated teat fabric has a fabric substrate with a coated outer surface normally exposed to degrading elements of the atmos. and a coated inner surface normally shielded by the fabric substrate from the degrading elements of the atmosphere. The coatings on the outer and inner surfaces of the fabric substrate each contain a polymeric binder flame retardant chemicals and water repellent chemicals. The improvement comprises the addn. of permethrin as an insect repellent to the coating on the inner surface of the fabric substrate, whereby the fabric substrate acts as a barrier that inhibits migration of the permethrin to the outer surface of the fabric and consequently inhibits exposure of the permethrin to the degrading elements of the atmosphere, thereby increasing the length of time the permethrin is an effective insect repellent. The coating on the inner surface pref. also contains a mobiliser for the permethrin such as a plasticiser, e.g. zirconium wax.

Description

114146

INSECT PROTECTING TENT FABRIC

This invention relates to coated fabrics which are refractory and waterproof and treated in accordance with the present invention for insect repellency.

It is known to coat the fabric with a protective coating system that incorporates water repellent and flame retardant chemicals to make the fabric suitable for military use in all weather conditions worldwide.

10 See, e.g., U.S. Patent Nos. 4,594,286 and 4,833,006.

Of course, in most climates, it is desirable that the tent can also be insect repellent. Insect repellents are known in the art, but having only a few days of potency makes them unsuitable for use in tent fabric protective coating systems.

Therefore, there is a general need for tent, tarpaulin, and protective fabrics (hereinafter collectively referred to as tent fabrics) that have a long-term ability to combat insect and disease-bearing insects.

The tent fabrics covered by the present invention have been treated to be durably waterproof and refractory, and to have an eye-pleasing appearance. To enable these features, ·. it is necessary to maintain the fabric treated with insect repellents that are effective for the intended use, without adversely affecting any other desired property of the fabric.

Several commonly known insect repellents have been tried to be used in tent fabric coverings. For example, there is a · · · * · * 'product experiment in which water repellant 30 and refractory tent fabric are insect repellent with dimethyl phthalate (DMP). It did not impair the fire resistance or waterproofing properties, but • had a shorter duration of action. desirable.

···, Benzyl benzoate, when applied to a conventional * t 35 refractory coating provides an ugly expression during application and drying. Dibutyl phthalate and dibutyl adipate appear much less visible in such.

Permethrin is a synthetic pyrethroid with 11414c 2 insecticidal, stunning and lethal properties. Pyre Troids mkl. their naturally occurring compounds and synthetically produced counterparts are effective against various pests such as house flies, mosquitoes, cockroaches 5 etc.

They are not harmful to plants, food, animals or humans and do not leave harmful residues. Permetine is environmentally friendly and has been found to be suitable for tent fireplace coating compounds containing water repellent and flame retardant chemicals without substantially diminishing the desired properties of the coated fabric.

Despite these very good properties, the increasing use of permethrin has been hampered by its relatively short-term insect repellent effect. This is because it is decomposed by oxygen and ultraviolet light into an inactive and insect repellant. The rate of this decomposition is dependent on the environment in which the permethrin is exposed, but typically occurs over a period of a few hours to a few days or weeks. This permethrin instability often limits its usefulness as an insect repellent.

Previous attempts to stabilize pyrethroid efflux have included encapsulation and the addition of antioxidants and light-stable ultraviolet light absorbent compounds to the pyrethroid solution. Encapsulation has not been effective because pyrethroids disassemble inside the enclosure almost as quickly as when unenclosed. Only mild success. in the reduction of discharge has been obtained by the addition of antioxidants and photostable ultraviolet light absorbent compounds

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pyrethroids solution. The counterpart to these mild successes is the ugly debris that is difficult to remove.

: _ Various techniques have been proposed to provide retarded release of pyrethroid for insects »; 35 sex. For example, U.S. Pat. 4,056,610 discloses a microcapsulated insect repellent compound in which a pyrethroid passes through a porous bark wall, and in which the pyrethroid 3 114146 insect repellent level is maintained on the outer surface of the bark wall for a period of four days (this is considered an extended period in the art). The control is achieved by killing insects that contact the pyrethroid released through the capsule wall.

Similarly, GB 2 217 740 discloses a packaging material comprising two membranes with insecticide material between them. The insecticide is pyrethrin. Japanese publication JP59065001 discloses an insecticide tape consisting of a support fabric. The first surface of the scaffold-10 has a layer of insect repellant compound and a layer of permeable compound repellent thereon. The other surface of the support fabric has an impermeable layer containing an insect repellent compound.

Ronning U.S. Pat. 4,765,982 discloses an insecticidal device having a plurality of coarse-surface cellulosic fibers, wherein the liquid surface is self-adhered to a liquid insect repellent compound micro-encased in a housing whose shell passes through a liquid insect repellent. The insect repellent 20 disclosed in U.S. Patent 4,056,610 to Barber is said to be the preferred insect repellent for use in the Ronning patent.

j:: Ronning insect repellant enriched with coarse cellulose fibers are shaped into webs, ribbons, sheets, cushions and other relatively thin forms; 25 suitable for use in special places such as narrow: v. placed in strips on the lower part of the building or on the door.

According to Ronning, planar fibers do not act as adhesive surfaces for microcontained insect repellents. Ronning Coarse Cellulose Fiber Enriched With Insect - '!!! 30 secondary repellents, not suitable for tent fabrics. Rough

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* 'The surface fibers have a poor texture and are neither waterproof nor refractory.

It is a primary object of the present invention to provide a tent fabric that retains its insect repellent properties for more than six months or more without compromising the waterproofing, fire resistance or other desired properties of the tent fabric, thereby providing the user with maximum comfort and safety.

According to the invention there is provided a coated tent fabric having a base fabric wherein the base fabric has a coated outer surface, which is usually exposed to atmospheric degenerating elements, and wherein the base fabric has a coated inner surface, usually protected against atmospheric degenerate elements, and the inner surface coatings each containing polymeric binders, flame retardant chemicals and water repellent chemicals, characterized by the addition of a permethrin and a plasticizer to an insect repellent coating on the inner surface of the base fabric, which acts as a barrier to the perm during which permethrin is an effective insect repellent.

The foregoing and other features of the invention will become more apparent from the following description, with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a tent;

Figure 2 is a cross-sectional view substantially along: line 2-2 of Figure 1; ; Figure 3 is a table showing mosquito stings ·; ··% in each month of the year, two tents in the test were treated with different repellents and one tent is an untreated control tent; • ·

Figure 4 is a table showing the percentage of dead mosquitoes in each month of the year, two tents in the test. was treated with various repellents and one tent is "30 untreated control tents; and; * Figure 5 is a graphical representation of the aging and weather effects of tent fabrics treated with various repellents and an untreated control tent, shown as mosquito strain protection.

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The base fabric of the insect repellent tent fabric of the present invention may be any suitable fabric. For example, it may be pure polyester woven fabric or a 50/50 blend of polyester and cotton, woven into an oxford fabric. The invention has been satisfactorily utilized in a base fabric made of continuous multi-filament yarns having a normal braid of one to two turns per 5 inches and woven into a pure woven fabric with 84 weft weft and 32 weft weft.

The fabric is coated with a compound that makes it waterproof, fireproof and insect repellent. The following is an example of coatings that can be used to practice 10 inventions:

Example 1

Insect Repellant Tent Cover Component Percent Action - Emkay B.C. 0.45 antifoam 15 - polyvinyl chloride polymer (Geon 576) 18.37 binder - dioctyl phthalate 5.99 plasticizer - phosphatated ester sodium salt 0.25 surfactant 20-antimony trioxide 13.83 flame retardant - kaolin (hydrated · formaldehyde) 1.in *: aluminized 25-methylcellulose 0.27 thickener «* *: v. ~ bromochlorinated hydrocarbon 27.66 flame retardant - zirconium multi wax 1.51 water retardant, - pigment system 1.79 dye * ;;; 30 - Acrylic Copolymer (Acrysol ASE-60) 0.98 Thickener:: #: - Metasol TK-100 Powder 0.15 Mildew Inhibitor - Permethrin 7.83 Pesticide 100.83% 35 Permethrin is a stationary material but can be made mobile by a plasticizer. In addition to acting as a waterproofing agent on the tent fabric, the zirconium wax also acts as a plasticizer and an oxygen barrier to permethrin. The wax forms a shell around the permethrin which protects the permethrin from the oxygen depletion effect after the permethrin reaches the surface of the coating. The wax 5 also moves the permethrin to the full strength and maintains sufficient permethrin on the inside surface of the coating and provides an effective insect repellent for a significantly longer period than has hitherto been possible.

To protect against environmental degradation such as ultraviolet rays, permethrin is not combined with a coating outside the tent but only with a coating applied to the side of the fabric that will be inside the tent. The wax and plasticizer that provide permethrin mobility are combined with the permethrin coating of the tent 15. Zirconium polyvinyl wax is also included as a waterproofing agent in the coating of the tent.

Thus, as shown in Figures 1 and 2, the insect repellent coating 13 of the water repellent and fire resistant tent 20 10 is applied to the base fabric 11 only on the side that remains inside the tent, and the conventional water repellent and fire resistant coating 12 is applied thereto on the base fabric 11. stay outside the tent.

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It is preferred that the outer tent cover is a cover disclosed and identified in U.S. Patent No. 4,400,151. 4,833, 006, issued May 23, 1989] ..) f to the Graniteville Company, domiciled in Graniteville • · »

South Carolina. The contents of the patent are hereby incorporated by reference.

• 1 · 30 The efficacy of permethrin as an insect repellent in tent fabric coating has been tested under field conditions for one year by the United States Department of Agriculture. They estimate using Aedes aeavpti mosquitoes to determine which treatment most effectively prevents 35 bites and most effectively stun tent-seeking insects.

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In particular, experiments were conducted to determine the persistence of insect repellent or killer compounds applied in tents. Three tents were used in the experiment. Each (family-type) tent was constructed of 24.4 m2 100% polyester-5 woven fabric with waterproof vinyl coating and zippered door opening cover. One tent was treated (inside only, including the floor) with the permethrin-containing coating of Example 1; another tent was treated with dimethyl phthalate (DMP) on the inside of the tent; and 10 third tent was untreated and used for comparison.

Three tents were erected on October 30, 1989, in the Gainesville, Florida, area of the USDA Medical & Veterinary Entomology Research Laboratory, an open lawn every two meters in a north-south row, with 15 doorways facing east. They were left uncovered for a year and completely exposed to the weather.

Efficacy estimates were made by weekly biopsy tests. Through the zipper of the door aperture, each tent had access to 75-80 seven-day-old, laboratory-selected, exposed female Aedes aeavpti · 'mosquitoes. Upon release, the doorway was closed with a traction V chain, and the tent flaps and a tailgate rear window were left open for ventilation (at all other times. ·· *. 25 flaps were closed). Mosquitoes were allowed to fly or * · land within the tent for three hours. Every hour after firing, mosquito KD, i.e., dead or moving mosquitoes, but not flying, and bites were recorded.

. Bites were observed and recorded for one minute in the tent after the volunteer's arm was uncovered through a small opening made by tearing open the zipper.

The hourly data indicated the treatment efficiency: t >>: rate of mosquitoes during three hours of exposure, i.e., either the treatment power was rapid (within the first hour) or 35 increasing (after two or three hours). The information also helped to indicate when the treatment began to lose its effectiveness due to the weather.

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After three hours, the mosquitoes were removed from each tent with a battery operated collector and counted. Care was taken to avoid contamination between treatments when entering an untreated, DMP-handled and permethrin-treated tent, respectively. The experimental results were recorded in the form of percentages, i.e. the ratio KD / bite divided by the total number of tent mosquitoes equals the percentage KD / bite.

Experiments were attempted each week on the same 10-day schedule. The bad weather from time to time made this difficult. However, at forty-eight weeks out of fifty-two weeks, the test could be performed. During the colder months, the tests were scheduled for warmer afternoons, while during the warmer months, the tests were conducted during the cooler morning hours.

The three-hour mean values for the 15 KD and bite data from the weekly experiments were computer-processed but not analyzed because only one replicate experiment was performed per week. The averages of this weekly data were computed on a computer to give a monthly idea of the power of the concept. The weekly bite data was calculated as a percentage protection using the following formula: Percent Protection: is equal to the difference between the number of mosquitoes biting the observation tent and the number of mosquitoes biting the treated tent: ·· divided by the number of mosquitoes biting the observation tent.

25 Results »·

The following Table 1 shows the mean monthly data for · · KD / bite as Ae. aeavbti was • · »in a weekly tent. The mean KD in the DMP treated tent was higher (2.7%) for one year than in the untreated 30 tent (0.9%). However, the mean KD of DMP was never as high as that of permethrin (58.6%). The monthly mean KD in the control tent was; (i>: fairly stable throughout the year (0.87% plus or minus 0.78%). The same was true for the DMP tent for the first 12 weeks 35 when the KD averaged 8.5% plus or minus 10.4%.

The average bite was 11.9% for the Permethrin-treated tent, 43.8% for the DMP-treated tent, and 58.6% for the 9,114,146 control tents. With permethrin, the average bite was less than 1% in the first six months, 8.5% in the next three months, and 33.8% in the last three months. In a DMP-treated tent, bite 5 increased from 21.3% to more than 40% after 11 weeks and remained at or slightly higher during the duration of the trial.

Figures 3 and 4 show comparisons of permethrin, DMP and untreated control data. The bite decreased in a DMP-treated tent with an average of 19.8% less bite and a 2.7% higher KD in the first 30 weeks with 10KD.

table 1

Aedes Aegybti average mosquito bite or gait percentage with three different weekly exposures to 15 different tent fabrics, one treated *) with only permethrin on the inside, one with dimethyl phthalate (DMP) on the inside and outside and one tent on the tent.

20 bounce rate bite.percent month permet- DMP concept permet- DMP concept-: ': number rini unresolved rains unexpressed::: 1 & 2 **) 81, 9 275 δ7§ 571 24.2 47.6, 77 253 99 , 0 14.4 0.3 0.0 26.1 52.3 '* 4 96.8 2.1 2.6 0.5 43.6 67.4 5 94.4 1.1 0.5 1, 5 46, 9 66.2 7 ': 6 71.3 1.4 0.5 2.1 50.5 61.5: 7 48.6 1.7 0.6 13.4 57.3 75.9: T; 30 8 56, 9 1.5 0, 9 4, 9 49, 6 56.6 9 58.9 1.1 0.2 7.1 42.8 58.8 10 24.3 1.4 0.9 27 , 2 48.4 51.7 11 7.2 1.5 2.1 34.9 46, 9 54.3 * ::: 12 5.0 0.7 0.2 39.6 45.4 45.5 35 years mean 58.6 2.7 0.9 11.9 43.8 57.9 *) Permethrin active repellency treatment was 0.075 ounces per square yard (2.543 g / m2) * '40 **) Data missing for weeks 1,2,3 and 8 because no tests were performed: performed. Therefore, data at weeks 4,5,6 and 7 were combined and analyzed for this two-month period.

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The above information is graphically represented in Figures 3,4 and 5.

The monthly average of bite and KD in the permethrin-treated tent is clearly better than in the DMP hand-tented tent and the tent-free tent. In the Permethrin-treated tent, the October-July bite percentage was well below 10%, except for May, when it was 31.3%. This provides the user with over 96% protection against mosquito bites for nine to 10 months. The mean decay rate was only about 88% over a six-month period (October to April), which means that although permethrin treatment provided less than 100% KD, the repellent had a strong effect on the mosquitoes that severely prevented biting within nine months.

15 The long duration of action (nine (9) months) is due to the protection provided by the wax and plasticizer, which covers the permethrin, and the fabric layer of the tent, which acts as a barrier to the migration of pyrethrin to the outer surface of the fabric, thereby preventing permethrin exposure. elements.

INFERENCE

From October to July, the mean mosquito bites * · perm tin i n g t h e t h e tent were less than 4% of the number of mosquitoes released. High overall protection (over. ···. 25 96%) against Ae.aeavbti bites (Figure 10) was maintained for up to 9 months.

Protection may last longer in intermittent than continuous weather applications. On average, KD was around 88% for the six months (October to April). ;;; Thus, although the permethrin treatment resulted in lower KD * '; * as treatment time declined, there was still a sufficient amount of residual toxicity that effectively reduced the bite: for nine months. Variables such as temperature, humidity, solar radiation, precipitation, and wind may have caused. 35 slightly different from the weekly test results. For example, when the sun's radiation was strongest, a 14% drop in the bite guard 11,114,146 was observed for permethrin at 7 months (Figure 1). Unexpectedly, DMP treatment caused a small amount of KD, indicating that it has some insecticidal activity. However, it is evident that permethrin was better than DMP in terms of KD, bite protection and persistence.

5 There is thus provided a tablecloth which is coated to be permanently waterproof and fire resistant, and for up to nine months to repel insects.

Although specific terms have been used in the description of the invention, they have been used for illustrative and general purposes only and not for purposes of limitation. It is intended that the scope of the patent be defined by the appended claims, having regard to the description and drawings, and the state of the art.

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Claims (4)

12 11414 (: A coated tent fabric having a base fabric (11), wherein the base fabric has a coated outer surface, usually exposed to atmospheric degeneration elements, and wherein the base fabric has a coated inner surface, usually protected against the atmospheric degenerate elements (11), ) outer and inner surface coatings (12,13) each containing polymeric binders, 10 fire retardant chemicals and water repellent chemicals, characterized in that an insect repellent is added to the inner surface coating (13) of the base fabric (11), both as a plasticizer and a base fabric (11). transfer to the outer surface of the fabric and thus exposure of permethrin to atmospheric degenerating elements, which increases the time during which permethrin is an effective insect repellent. A coated tent fabric according to claim 1, characterized in that the plasticizer added to the inner surface coating (13) of the base fabric (11) is intended to move the permethrin to full strength and to maintain sufficient permethrin on the inner surface of the base fabric (11). for at least nine months as an effective insect repellent. 25 Coated tent fabric according to claim 2, characterized in that the permethrin is applied only to the inner surface coating (13) of the base fabric (11). Ύ 304. A tent fabric according to claim 1 or 2, characterized in that the plasticizer is zirconium wax. 1 »13 114146