Detergent composition for treating fabrics with insecticides

Abstract

A detergent composition including permethrin is disclosed that is particularly adapted to launder clothing or other personal fabrics. Laundering clothing with composition provides effective insect repellant properties to the clothing for at least 14 days. The detergent composition is especially useful for control of mosquitoes and other insects, thereby reducing the incidence of malaria, zika virus, and other diseases.

Claims

1. A laundry detergent for cleaning fabric such that the fabric immediately becomes insect repellent and kills insects on contact for at least 14 days comprising a liquid laundry detergent and a liquid permethrin solution wherein the laundry detergent comprises 0.21 ounce of 36.8% permethrin concentrate per 1 gallon of detergent.

2. The laundry detergent for cleaning fabric of claim 1 further including products selected from the group consisting of bleach, fabric softeners, starch, odorants, and laundry additives.

3. The laundry detergent of claim 1 further including an additive selected from the group consisting of oil of lemon, oil of citronella, and oil of eucalyptus.

4. (canceled)

5. The method of making a permethrin laundry detergent composition comprising mixing 0.21 ounce of 36.8% permethrin concentrate per 1 gallon of water, to make a permethrin water solution, and impregnating a dry laundry detergent support having a pore volume of 0.26 ml/g with the permethrin water solution using capillary action, and drying the composition under reduced pressure.

6. A method of making a dry laundry detergent which repels and kills insects on contact for at least 14 days, including permethrin, comprising determining the pore volume of a dry detergent support using nitrogen physisorption followed by bet calculations then mixing 0.21 ounce of 36.8% permethrin concentrate with 2 ounces of liquid laundry detergent and 1 gallon of water, and adding the permethrin/liquid laundry detergent/water solution to the dry detergent support in an amount equal to the pore volume of the dry detergent support, wherein a fabric washed with the dry laundry detergent repels and kills insects that contact the fabric.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] FIG. 1 shows FTIR spectra of permethrin loaded detergent. Part (a) shows detergent containing no permethrin vs. detergent loaded with permethrin according to the invention at room temperature. Part (b) shows an FTIR spectra of detergent containing no permethrin vs. detergent loaded with permethrin according to the invention at 150° C.

[0020] FIG. 2 shows a depiction of a transmission high vacuum cell with wafer in the (a) front view (b) side view which was used to measure FTIR spectra of fabrics treated according to the invention.

[0021] FIG. 3 shows the kinetics of permethrin depletion on cloth after treatment. Part (a) shows IR Spectra of cloth washed with detergent containing no permethrin and detergent including permethrin according to the invention. Part (b) shows an integrated peak area vs. time. Part (c) extrapolates part of (b).

DETAILED DESCRIPTION OF THE INVENTION

[0022] A dry impregnation process has been found to produce very good results, although it is expressly understood that the invention is not to be limited to the dry impregnation process.

[0023] The novel detergent composition of the invention is prepared at room temperature under reduced pressure by dry impregnation of detergent support with a 36.8 vol % aqueous solution of permethrin in a rotary evaporator with an aspirator. Dry impregnation is a common technique used in catalysis in which a metal-containing solution is added to a catalyst support containing the same pore volume as the volume of the solution that was added. Capillary action draws the solution into the pores. Solution added in excess of the support pore volume causes the solution transport to change from a capillary action process to a diffusion process, which is much slower and wets the support in excess. Dry impregnation was particularly adopted here to avoid extra wetting of the detergent. To determine the pore volume of the detergent, Nitrogen Physisorption followed by BET calculations are carried out. A pore volume of 0.26 ml/g was established for the detergent support used herein.

[0024] After the pore volume of the detergent support being used has been determined, the following procedure is followed: [0025] A sample of dry detergent is collected in an agitator at room temperature (Agitation is adjusted based on the sample size to eliminate the mass transfer limitation). [0026] A volume of permethrin solution equal the pore volume of the sample of detergent collected is then added dropwise to the detergent at 1 drop/second. [0027] The sample is left in the agitator for 15-20 minutes to allow for thorough mixing. [0028] The detergent mixture is then placed in the oven to dry for 20 minutes at 100° C. (A rotary evaporator can also be used in this step and it is in fact the preferred technique). Reduced pressure may be used when drying the detergent composition of the invention. [0029] A preferred ester combination would be added as per discretion at production to give the detergent a suitable smell.

[0030] To use the novel composition, the user merely has to wash his/her clothes as usual with the insecticidal composition and dry them. The cloths immediately become insect repellent and kill insects on contact for a time period before the substance wears out. The clothes or bed netting can be washed by hand using the insecticidal composition, or the composition can used in the manner of a conventional laundry detergent, in a normal washing machine.

[0031] A preferred embodiment for forming a liquid composition to which the invention is not limited comprises mixing 0.21 ounces of 36.8% permethrin solution with 2 ounces of liquid detergent and 1 gallon of water.

[0032] A preferred embodiment for forming a dry composition to which the invention is not limited, comprises mixing 0.21 ounces of permethrin 36.8% liquid concentrate to per 100 grams of dry detergent then adding the permethrin/dry detergent composition to 1 gallon of water, and drying the composition under reduced pressure.

[0033] Additives: Mix permethrin with odorant (vanilla extract) before impregnation in a 1:1 mole ratio. Suitable additives include oil of lemon, oil of eucalyptus, and oil of citronella, or combinations thereof. Eucalyptus Globulus, also known as Blue Gum is a particularly preferred source of eucalyptus oil.

[0034] To make the dry composition 0.21 ounces of liquid 36.8% permethrin concentrate is added to 100 grams of dry detergent. This mixture is then added to 1 gallon of water.

[0035] Referring to FIG. 1, an FTIR spectra of permethrin loaded detergent is shown. Part (a) represents a detergent with no permethrin vs. detergent loaded with permethrin at room temperature. Part (b) shows the FTIR spectra of a detergent with no permethrin vs. detergent loaded with permethrin at 150° C.

[0036] In order to understand the stability of permethrin on detergent, in situ IR spectroscopic studies were employed to elucidate surface interactions. The IR spectroscopic studies were undertaken using a high vacuum transmission cell. The results are seen in FIG. 1. Detergent with no permethrin and detergent loaded with permethrin were individually pressed into a translucent self-supported wafer and spectra were taken in a high vacuum. Monitoring the characteristics bands for permethrin provided a clear picture of the surface stability of permethrin on detergent.

[0037] IR studies were chosen for this analysis because IR peak assignment characteristics of a permethrin molecule has been extensively studied and reported in the literature. The broad band around 3500 cm.sup.−1 is assigned to physisorbed water molecules on the detergent. Peaks around 2950 and 2870 cm.sup.−1 are indicative of asymmetric and symmetric C—H stretching respectively which are common bands found in detergent and enhanced by permethrin. Bands below 2500 cm.sup.−1 are assigned to different stretching vibrations within a permethrin molecule as shown in FIG. 1.

[0038] FIG. 1(a) shows the IR spectra of a blank detergent sample, or sample with no permethrin, and a sample loaded with permethrin. As observed from the IR spectra, new bands below 2500 cm.sup.−1 were seen on the samples loaded with permethrin. These bands are representative of vibrations within a permethrin molecule. This indicates that permethrin is very well stabilized within the pores of detergent and no surface reaction or degradation of permethrin is promoted by the detergent. In FIG. 1 (b), an IR spectra of detergent without permethrin vs. permethrin on detergent is taken at room temperature and 150° C. As a result, all the vibrational stretches are from permethrin contribution. The purpose of this experiment was to determine the stability of permethrin at high temperatures. A temperature of 150° C. was chosen because it is well above the temperature limit for using the proposed product for any practical purpose. As seen in the spectra, the peaks indicative of permethrin bands persist at this temperature. This indicates that permethrin is thermally stable and the detergent does not have any catalytic effect on permethrin even at higher temperatures up to 150° C. The negative band seen at 3500 cm.sup.−1 after heating at 150° C. indicates that evaporation and desorption of physisorbed water from the surface of the detergent was the only result of heating.

[0039] Based on these results, it was concluded that permethrin remains in its active form upon loading in detergent. No degradation was observed on the molecular structure of permethrin even after exposure to harsh operating conditions.

[0040] Additional embodiments of the invention include concentrates to be added to conventional laundry detergents. Such concentrates could be marketed in soluble packets for addition to laundry prior to washing, much as bleach or the like is conventionally added. Alternatively, the permethrin composition could be incorporated into a solid fabric softener, as described in U.S. Pat. No. 9,150,819, issued to Wetrosky et al, fully incorporated herein. A concentrate of permethrin could further include products selected from the group consisting of bleach, fabric softeners, starch, perfumes, and laundry additives.

[0041] Another embodiment contemplated by applicant includes incorporating a permethrin concentrated solution in microcapsules to achieve a sustained release of insect repellant substances. Such microcapsules are well known, and described in U.S. Pat. No. 8,460,792, to Smets et al, fully incorporated herein. The microcapsules could be premixed with either a solid or liquid laundry detergent, or provided as a laundry additive to be added during the wash cycle.

Experimental

Sample Preparation

[0042] Two pieces of white cotton clothes were used for this experiment because of their transparency to infrared light. White pieces of 13 other materials were also used. The first piece of cloth was washed with off the shelf detergent, containing no permethrin, and the second piece was washed with detergent according to the invention loaded with permethrin. The two samples were then rinsed with lab grade de-ionized water with a purity of 18.2 MΩ. The samples were then dried in an oven at 110° C. for 20 minutes.

Infrared Spectroscopic Analysis

[0043] The dried samples of cloth were each loaded in a transmission infrared spectroscopic cell and spectra were collected using 64 scans. The cloth without permethrin was first measured as a control. The cloth washed with detergent according to the invention was then measured and the individual —C═C— and —C—O—C— vibrational stretching from permethrin were monitored. Infrared spectra of the cloth washed with permethrin were taken over a fourteen-day period for the first test and 12 days for the subsequent tests in order to elucidate the kinetics of permethrin depletion.

2. Results and Discussion

[0044] FIG. 3 (a) represents the infrared spectra of a cotton cloth sample washed with off the shelf detergent (bottom) and a cloth sample washed with detergent according to the invention (top). The first sample was used as a control and only the second sample including detergent according to the invention was used for the analysis. The peaks at 1720 and 1570 cm.sup.−1 represents vibrational stretches of —C═C— and —C—O—C— respectively which is indicative of the presence of permethrin. The integrated area of the peaks at 1570 cm.sup.−1 was plotted against the time of the experiment in order to determine the lifespan of permethrin on the cloth. FIG. 3 (b) shows a 2.sup.nd order polynomial relationship of permethrin depletion over time during a 14 day period. The data was extrapolated to determine the lifespan of permethrin on cloth after treatment with detergent according to the invention. The extrapolation as seen in FIG. 3 (c) indicates that permethrin is active on the cloth over approximately 27 days. Similarly, the lifespan of permethrin in different cloth materials is seen in Table 1 below.

TABLE-US-00001 TABLE 1 Material Lifespan of Permethrin (Days) 100% Cotton Plain 25 100% Polyester Net >18 65% Polyester 35% Cotton >18 100% Polyester Silk >22 100% Cotton Jeans 18 65% Polyester 35% Rayon >19 80% Polyester 20% Spandex 19 45% Polyester 55% Cotton 21 55% Linen 45% Cotton >22 40% Polyester 60% Cotton 19 100% Polyester wool >14 59% Cotton 41% Acrylic Wool >16 100% Cotton Towel >15

CONCLUSION

[0045] Detergent according to the invention is effective for transferring an active insect repellant on clothes. Physicochemical characterization indicates that the ingredient is active on the cloth for greater than 2 weeks and up to 27 days depending on the clothing material.

SUMMARY

[0046] IR Spectra were taken everyday for 14 days to determine the amount of active Permethrin on cloth. [0047] Polynomial trend in an order of 2 was observed when the data was fitted. [0048] Data was extrapolated after 14 days to determine how long Permethrin will last on cloth. [0049] Extrapolation indicates that Permethrin will last for approximately 27 days.