CA2802515A1 - Double walled rodent repellent bag - Google Patents

Abstract

An article, such as a double walled bag for food security, which repels rodents such as the brown rat, black rat and the house mouse. The article may be made of an interior wall, which serves as a barrier between the food/contents and the filling material, a filling material, which may incorporate secondary substances to provide additional function to the bag and an exterior wall, which may protect the filling material from the surrounding environment. The article's filling material may also contain a co-spun mineral fibre such as glass wool, steel wool, stone wool, or rock wool. The article's filling material may include an odorant composition containing menthol, camphor, lemon oil, salicylic acid esters, or citronella.
The filling material may also include an irritant composition containing capsaicin, or piperine.
Lastly, stabilizing additives may be added to the polymer fibre to prevent repellent degradation.

Description

Title: Double Walled Rodent Repellent Bag Specification Field Of The Invention The invention is in the field of bags intended for food storage and devices used for rodent control purposes.
Background Of The Invention Rodents such as the brown rat, black rat, and the house mouse are known to consume and contaminate a significant portion of stored food and seeds, particularly in the case of small-scale farming operations in developing countries. The food industry documents general principles on the handling of ingredients and components, as well as on the final products sold to commercial users and consumers. Logically, these requirements are a prudent way to prevent contamination from dust, dirt, or animal contamination. Small-scale farming families in developing nations can be devastated by a substantial loss of stored food, which is often their only means of sustenance. Grains are principally stored in woven polyolefin bags, which are a prime target for rodents.
A number of relevant bag designs are known, which can be used as garbage bags, shopping bags, or storage containers, but none of them are satisfactory in terms of cost, safety, durability and efficacy of repellent properties. Conventional food storage bags and sacks have tended to use at least one layer, usually an exterior layer, of a woven polyolefin material, which is closed by stitching. This sort of construction has the significant disadvantage that, on storing of the bag, it becomes extremely easy for the rodents to chew through the bag, spoiling the contents, and possibly infecting them with rodent disease. Moreover, the rodents can easily chew through the stitching thread, spilling the contents of the bag.
Other bags are made of a tougher plastic material but suffer a similar problem in that the closure of the bag is not guaranteed. Once again, this carries the risk of large holes being gnawed into the bag and spilling and/or spoiling its contents.
Some rodent repellent-coated bags already exist on the market, for example the Mint-X Rodent Repellent Trash Bags (Dussich, J.A., & Dussich, J. in Mint-X Corp, US260872-A1, CA2758319-Al, W0162834-Al, AU250684-Al, MX001430-Al, EP2451272-Al; Katoh, M., & Dussich, J. in JAD Corporation of America, US7811597 B2). In this product, the repellent (e.g. menthol) is incorporated as an integral component of the polymer forming the bag.
Therefore, both the contents of the bag and the exterior environment are exposed to the repellent, where it may cause an allergic reaction or other form of irritation in humans. Repellent degradation is another possible pitfall of existing designs. Thus, a stabilizing additive or use of a repellent with a longer half-life is warranted.
The existing repellent solutions, which need to be within the scope of a bag or sac for storing grains, can be classified into several categories. Perhaps the least documented in patents or scientific articles is the physical or topological barrier, which comprises a material whose strength and surface properties would make it difficult and irritating for the rodent to chew through. Common lore seems to suggest that materials such as steel wool might be effective in this case, by lodging between their teeth and causing them pain, or even by causing injuries when ingested. While no conclusive evidence was found to support or disprove this claim, several kinds of building insulation, composed of mineral fibres, are deemed to have additional critter repellent properties (Roxul Inc, 2012).
In terms of the chemical repellents, several inventions and studies suggest that a number of odorant chemicals would be able to provide repellence. According to Vayas et al. (2007), rats experience aversion to feline urine, a variable mixture of components. U.S.
Patent 4,735,803 discloses an animal repellent composition comprising lemon oil and alpha-terpinyl methyl ether, where lemon oil is a mixture, which could contain any of 27 listed ingredients.
Furthermore, U.S. Patent 5,877,223 describes the use of pulegone and piperitone as odorants.
These patents mostly target dogs and other animals, not focusing specifically on rodents. Prior art also exists for single molecule odorants or simple mixtures as pertaining to rats and rodents. In U.S. Patent 5,571,582, a garbage bag comprising several odorants is described for the repellence of various animals, including, crows, cats, dogs, and rats. The patent indicates that the presence of 4500-4700ppm of methyl salicylate, ethyl salicylate, iso-butyl salicylate, or menthol is successful in repelling rats within a weeklong period. U.S.
Patent 7,380,370 B2 describes the use of felinine within a porous medium in a device meant to repel rodents.
Felinine is a component in feline urine, and the smell may be undesirable in the context of food. In U.S. Patent 7,811,597 B2, a garbage bag containing 10-15,000 ppm w/w of salicylic acid ester, menthol, and/or camphor, is used to repel animals and birds, including rats. In U.S.
patent 8,142,801, 2-undecanone, the main ingredient in rue oil, is used in the context of repelling rodents, although this compound is highly volatile.
The other category of chemical repellents is irritants. Capsaicin is a chemical compound found in hot peppers, which has been shown to deter rats from gnawing on cables at concentrations as low as 2% (Shumake et aL, 2000) as well as reduce egg predation from nests (Baylis et aL, 2012). Capsaicin is in widespread commercial use as a pest repellent, usually in conjunction with other active molecules, such as piperine (Mongiovi, 2011). U.S. Patent 908,753 and Japan Patent 314,346 are among a number employing this compound in rodent repellent devices.
The invention seeks to address the problem of rodent infestations in food stores by incorporating a safe, non-lethal repellent into a design for a food storage device.
Summary Of The Invention The present invention consists of a double walled bag comprising an interior wall, which contains the contents of the bag, an exterior wall, which protects the contents of the bag from the environment, and a filling material between the two walls which incorporates secondary substances to provide additional rodent repellent functions to the bag. The invention increases food security in geographic areas prone to rodent infestation. The invention is designed to deter rodents due to the scent of the odorant and the taste and irritant properties of the other chemical repellent, which are located in the intertwining matrix (filling), composed of a polymer fibre and a mineral fibre. The tangle of polymer will lead to a greater coating surface area for the odorant/ repellent and will discourage the rodents from trying to work through the tangle of fibres to reach the interior wall. Ideally, the filling material is tougher, for example incorporating steel wool, which sticks in the teeth of rodents and irritate them as they chew. Moreover, stabilizing additives such as cyclodextrins can be added to the polymer fibre to prevent repellent degradation. Even though the repellent(s) and odorant(s) used are non-toxic, the interior wall is still desirable to prevent the taste of the repellent/odorant from transferring to the food, and prevent contamination of the stored contents of the bag. The exterior wall prevents any potential skin irritation due to direct contact with the repellent or odorant and adds strength to the bag. Since this design is building upon the design of currently used polyolefin bags, the cost, feasibility, and durability of the bags would be similar to that of currently used bags.

i Brief Description Of The Drawings In the drawings, which form a part of this specification, FIG. 1 shows a side cross section of a double walled bag (10) incorporating an interior wall (1), exterior wall (2), a filling material (3) comprising of an intertwining matrix polymer, and a content storage space (4);
FIG. 2 shows a plan view of the exterior wall (2) with a partition separating seam (5) sewing the interior and exterior walls together and dividing the wall into smaller partitions (6).
Detailed Description Of The Invention For the purposes of this document, the following terms shall be defined as follows:
Bag, sac, or sack will be used to denote the overall invention (10) encompassing all the walls and filling materials.
The pests, which the bag seeks to repel, will constitute rodents such rats and mice.
Irritants will be defined as compounds which cause pain or discomfort to the pest's eyes, skin or mouth upon attempted chewing of the bag (10).
Odorants will be defined as compounds whose odour or pungence will deter the pests without requiring them to come in direct contact with the bag (10).
The contents shall be defined as any substance, which is placed in the bag to protect it from the pests.
The present invention consists of a double walled bag (10) which is inexpensive, durable, and which can enter into widespread use by farmers in developing countries. As seen in FIG. 1, the proposed invention is a bag (10) which consists of an interior wall (1), which contains the contents (4) of the bag, an exterior wall (2), which protects the filling (10) from the environment, and a filling material (3) between the two walls, which is infused with rodent repellent chemicals and properties. The present invention seeks to stop the rodents from consuming the contents, spoiling the contents with their droppings, gnawing holes in the packaging material causing spillage of contents, and from infecting the contents with rodent diseases. The incorporation of a repellent and/or an odorant instead of a lethal pesticide serves to prevent unsanitary conditions caused by dead rodents in the storage space and ensures that the contents enclosed are safe for human consumption. Apart from these concerns, feasibility for use in developing nations (low cost, easy to transport and set up) is also warranted. The invention encapsulates a design, which is strong, stackable, and residue-free. The present invention also seeks to improve the shortcoming of repellent degradation.

The half-life of free capsaicin at 55 C is around 40 hours (Subramanian eta!, 2008). However, we expect the stability of bound molecules to be much greater, with stabilizing additives such as cyclodextrins added to the polymer fibre (Uyar et al, 2009). Furthermore, the temperature of the storage space is expected to be lower than 55 C for most of the storage time. In addition, since the repellent is located within the filling material (3) and is isolated from both the contents and the environment, a higher initial concentration of repellents than necessary will extend the effective life of the bag (10) without increasing risk of potential repellent contamination of the contents.
The present invention seeks to provide threefold rodent protection for the stored goods. Two categories of chemical repellents are proposed to incorporate into the intertwining polymer matrix, which comprises the filling (3). An odorant repellent will discourage rodents from approaching the exterior of the bag (10) due to its strong odour. In the case where the odorant proves insufficient, and the exterior wall (2) is penetrated, an irritant will act on the rodent's skin, eyes, and mouth, which will deter it from continuing to chew through.
The third level of protection comes from the shape and physical composition of the filling (3).
An intertwining, or tangled, polymer fibre is sufficiently soft for the rodent to chew through without difficulty, but the tangle would require more effort to work through. Coating the fibres with an irritant makes the task of breaching the filling difficult, while the fibre presents a large surface area for coating by the repellent and the tangle increases the rodent's time of exposure. To further present a physical barrier to the animal, the polymer can be intertwined with a physical irritant mineral fibre, such as steel, stone, or glass wool, which would be painful to chew through.
Several naturally occurring repellents can be used. We recommend a combination of capsaicin and menthol. Capsaicin and piperine could be used at a combined concentration of 1-3% w/w or 150,000 to 450,000 Scoville heat units. According to Dr. Kevin L. Goodner (2008), the Scoville heat rating of a jalapeno pepper is approximately 3,300 Scoville units. Habanero peppers have a Scoville heat rating on the same order of magnitude as the proposed repellent.
This will serve as an effective eye, mouth, and skin irritant if the rodents attempt to chew through the bag (10) but still be non-lethal and safe for humans. On the other hand, we propose menthol as a preventative measure, as used in the previously mentioned garbage bag design as used in US patent 781159782. The menthol will discourage rodents, whose sense of smell is very strong, from approaching the bag (10). Various methods for coating a polymer fibre in repellent exist, and can be applied to the proposed design.
A tertiary substance can be integrated into the polymer fibre to bestow additional properties to the filling (3). This is especially necessary when organic molecules with short half-lives are imbued into the polymer. In order to increase the longevity and efficacy of the bag, stabilizing additives such as cyclodextrins can be added to the polymer along with the irritant and odorant repellents.
As shown in FIG. 2, the bag (10) can be strengthened by the addition of a seam (5), sewing the interior and exterior walls together and separating the bag wall into a plurality of smaller partitions. This structure will fix the filling in position, ensuring an even distribution at all times and preventing the filling from sagging or localizing to one section of the bag (10). In addition, it will localize any damage done by rodents chewing through and prolong the life of the bag (10).
Citations/ References Baylis, S. M., Cassey, P., & Hauber, M. E. (2012). Capsaicin as a deterrent against introduced mammalian nest predators. The Wilson Journal of Ornithology, 123(3), 518.
Dussich, J. A., & Dussich, J. Article, useful as e.g. trash bag to repel animals e.g. cats, comprises synthetic resin composition of a thermoplastic polymer e.g. polyethylene and a master blend having another thermoplastic polymer (polyolefin) and odorant e.g. menthol.
US234082 26 Sep 2005 US822336 24 Jun 2010 CA2758319 17 Nov 2011 Etscorn, F. T., & Torres, L. Prepn. of animal repellent based on capsicum -for protecting objects such as trash bags from attack by rodents. US139432 20 Oct 1993 US908753 08 Aug 1997.
Goodner, K. L. (2008). Capsaicin levels in poblano and jalapeno pepper concentrate. (Technical Note No. SEN-TN-0004). Hamilton, OH.: SENSUS, LLC, Jones, A. (2012). In EcoBlend L. (Ed.), Pesticidal compositions and methods of use thereof Katoh, M. (1996). In Mitsubishi Chemical Corporation (Ed.), Garbage bag or container doi:

Katoh, M., & Dussich, J. (2012). In JAD Corporation of America (Ed.), Garbage bag or container.

Katz, I., & Withycombe, L. (1988). In International Flavors and Fragrances Inc. (Ed.), Repelling animals wth compositions comprising lemon oil and alpha-terpinyl methyl ether.

Livingston, A. (2008). In Armex L. (Ed.), Repelling rodents. US7380370 Mason, J. R., Dolbeer, R. A., & Preti, G. (1999). In Monell Chemical Senses Center (Ed.), Naturally-occurring odoriferous animal repellent doi: US5877223 Mongiovi, M. (2011). Havahart critter ridder. (Material Safety Data Sheet (MSDS)). Lititz, PA:
Woodstream Corporation.
Roxul Inc. Are roxul products rodent resistant? Retrieved 11/15, 2012, from http://www.roxul.comistone+wool/faciftf1270 Shumake, S. A., Sterner, R. T., & Gaddis, S. E. (2000). Repellents to reduce cable gnawing by wild norway rats. The Journal of Wildlife Management, 64(4), 1009-1013.
Subramanian, G., Karthik, A., Kamath, S., Prabahar, K., Ranjithkumar, A., Pathak, S., & Udupa, N.
(2008). Stability-indicating HPTLC determination of capsaicin in the bulk drug. JPC -Journal of Planar Chromatography - Modern TLC, 21(4), 271-275. doi:
10.1556/JPC.21.2008.4.9 Thermoplastic resin cornposition for prevention of animal bite - comprises capsaicin compound and poly:Olefin resin. JP314346 01 Dec 1995:
Uyar, T., Hacaloglu, J., & Besenbacher, F. (2009). Electrospun polystyrene fibers containing high temperature stable volatile fragrance/flavor facilitated by cyclodextrin inclusion complexes. Reactive and Functional Polymers, 69(3), 145-150.
Vyas, A., Kim, S., Giacomini, N., Boothroyd, J. C., & Sapolsky, R. M. (2007).
Behavioral changes induced by toxoplasma infection of rodents are highly specific to aversion of cat odors. Proceedings of the National Academy of Sciences of the United States of America, 104(15), 6442-6447. doi: 10.1073/pnas.0608310104

Claims (10)

1. A double walled bag comprising an interior wall adjacent to the interior space, an exterior wall, and a filling material with rodent-repelling properties situated between the interior and exterior walls.

2. The bag of claim 1, wherein the filling material comprises an intertwining matrix polymer, a sponge-like porous material, or a combination of the two.

3. The bag of any one of claims 1 or 2, wherein the filling material comprises a combination of an intertwining matrix polymer and a mineral fibre.

4. The bag of claim 3, wherein the mineral fibre is glass wool, steel wool, stone wool, rock wool, or a combination thereof, acting as a physical aggravator upon chewing.

5. The bag of any one of claims 1 to 4, wherein the filling material contains an integrated secondary substance with irritant properties.

6. The bag of any one of claims 1 to 5, wherein the filling material contains an integrated secondary substance with odorant properties.

7. The bag of claim 5, wherein the irritant composition contains capsaicin, piperine, or a combination thereof.

8. The bag of claim 6, wherein the odorant composition contains menthol, camphor, lemon oil, citronella, methyl salicylate, ethyl salicylate, iso-butyl salicylate, camphor, or a combination thereof.

9. The bag of any one of claims 1 to 8, wherein the intertwining matrix polymer contains an integrated tertiary substance.

10. The bag of any one of claims 1 to 9, wherein the bag comprises a plurality of partitions, formed by sewing together the interior and exterior walls and entrapping the filling material within the partitions.