The present invention relates to a fragrance emitting patch that a user can attach to the body or an article of clothing, and more particularly to a fragrance emitting patch including at least one layer including a fragrance and an adhesive applied to the patch for selectively securing the patch to the body or an article of clothing.
Fragrance emitting devices are generally used to deliver a pleasing scent to the user. These devices have been used in the past to mask undesirable odors and can also be functionalized with an odor-controlling agent. The prior art discloses fragrance emitting patches that purport to deliver fragrance when a user attaches the patch onto their body or an article of clothing. These patches generally include one more or more layers of material, at least one of which is provided with a fragrance. Fragrance emitting patches generally include a positioning adhesive applied to an external surface of the patch for selectively adhering the patch onto the user's skin or article of clothing. Patches with multiple layers may also include a construction adhesive used to affix the layers of the patch to one another.
The inventors have discovered that many fragrances used in known fragrance emitting patches will migrate into the adhesive components of the patch and undesirably interact with the adhesive by altering its chemical composition. In particular, the inventors have discovered the aromatic components of many fragrances tend to plasticize the end blocks of standard hot melt adhesives. The inventors have discovered that this interaction causes the adhesives to perform poorly by reducing the cohesiveness and internal strength of standard construction and positioning adhesives. Specifically, the inventors have discovered that the interaction between the fragrance and positioning adhesive may cause the patch to detach from the surface to which it is applied and in a multilayer construction the interaction of the fragrance with the construction adhesive may cause the undesirable delamination of the layers of the patch.
The inventors have further discovered that in order for a fragrance emitting patch to provide the desired intensity of scent, and in order for the scent to last for a sufficient period of time during use, the fragrance must be applied to the relevant layer of the patch in a relatively high add on amount. However, the inventors have discovered that the use of a high add on amount of fragrance exacerbates the degradation of the adhesive described above.
In view of the foregoing, the present invention provides a fragrance emitting patch that has the ability to incorporate high levels of fragrance without sacrificing the functionality of the construction and positioning adhesives used within the patch.
In view of the foregoing, the present invention provides, according to a first aspect of the invention, a fragrance emitting patch including a primary porous layer having a top and a bottom surface, a secondary layer having a top and a bottom surface, a construction adhesive arranged between the primary layer and the secondary layer for securing the primary and secondary layers to one another, wherein the primary layer is provided with a fragrance, and wherein an absolute difference of a Hildebrand solubility parameter of the construction adhesive and a Hildebrand solubility parameter of the fragrance is greater than 1.5.
The present invention provides, according to a second aspect of the invention, a fragrance emitting patch including a primary porous layer having a top and a bottom surface, a secondary porous layer having a top and a bottom surface, a positioning adhesive deposited on the bottom surface of the secondary layer, a construction adhesive arranged between the primary layer and the secondary layer for securing the primary and secondary layers to one another, wherein at least one of the first and second layers is provided with a fragrance, wherein an absolute difference of a Hildebrand solubility parameter of the construction adhesive and a Hildebrand solubility parameter of the fragrance is greater than 1.5.
The present invention provides, according to a third aspect of the invention, a fragrance emitting patch including a primary porous layer having a top and a bottom surface, a positioning adhesive applied to a bottom surface of the primary porous layer, wherein the primary layer is provided with a fragrance, and wherein an absolute difference of a Hildebrand solubility parameter of the positioning adhesive and a Hildebrand solubility parameter of the fragrance is greater than 1.5.
The present invention provides, according to a fourth aspect of the invention, a fragrance emitting patch including a primary porous layer having a top and a bottom surface, a secondary porous layer having a top and a bottom surface, a positioning adhesive deposited on the bottom surface of the secondary layer, wherein the primary porous layer and the secondary porous layer are secured to one another in aN adhesive free manner, wherein at least one of the first and second layers is provided with a fragrance, wherein an absolute difference of a Hildebrand solubility parameter of the positioning adhesive and a Hildebrand solubility parameter of the fragrance is greater than 1.5.
The present invention provides, according to a fifth aspect of the invention, a fragrance emitting patch including a nonwoven cover having a top and a bottom surface, a layer of polymeric film having a top and a bottom surface, a construction adhesive arranged between the bottom surface of the cover and the top surface of the layer of film for securing the cover and the layer of film to one another, a positioning adhesive deposited on the bottom surface of the second layer, wherein at least one of the cover and the film is provided with a fragrance in an amount in the range of about 3 gsm and about 15 gsm, wherein an absolute difference of a Hildebrand solubility parameter of the positioning adhesive and a Hildebrand solubility parameter of the fragrance is greater than 1.5, and wherein an absolute difference of a Hildebrand solubility parameter of the construction adhesive and a Hildebrand solubility parameter of the fragrance is greater than 1.5.
As used herein, the term “construction adhesive” refers to any adhesive that is used to join two layers of material to one another.
As used herein, the term “positioning adhesive” refers to any adhesive that is used to removably attach a fragrance emitting patch to a user's skin or clothing.
In one embodiment of the invention, as shown in
The inventors have discovered that purposely selecting fragrances that are substantially insoluable in the adhesive compounds used in the fragrance emitting patch minimizes the undesireable reaction between these components. The Hildebrand solubility parameter is used often in chemistry to predict when two solutions are soluble in one another. According to the theory proposed by Dr. Joel Hildebrand, two solutions will be soluble when the Hildebrand solubility parameter is equal, and insoluble when the Hildebrand solubility parameter is not equal. The difference between the two values is roughly related to the extent of insolubility between the two solutions. The Hildebrand solubility parameter (δ(SI)) is derived from the heat of vaporization (ΔH), the universal gas constant (R), the temperature (T), and the molar volume of the solution (Vm), and is calculated using the following formula:
δ(SI)=[(ΔH−RT)/Vm]1/2
The resulting value is a property of a particular solution at a given temperature. In the international system of units (SI), the universal gas constant (R) is approximately 8.314 J·K−1mol−1. The Hildebrand solubility parameter has the units of MPa1/2.
The Hildebrand solubility parameter of common adhesives and fragrances is provided in TABLE 1 below:
According to the present invention, the adhesive(s) and fragrance(s) employed in the fragrance emitting patch have a solubility parameter absolute value difference of greater than 1.5, preferably greater than 3.0, and most preferably greater than 5.0. This relationship can be expressed by the follow equation:
|δa−δf|>1.5; where
The fragrance emitting patch 10 may be optionally provided with a removable backing layer 22, shown in
According to one aspect of the invention, the primary layer 12 is constructed from a porous non-woven web material. The primary layer 12 may be composed of only one type of fiber, such as polyester or polypropylene or it may include a mixture of more than one fiber. The primary layer 12 may be composed of bi-component or conjugate fibers having a low melting point component and a high melting point component. The fibers may be selected from a variety of natural and synthetic materials such as nylon, polyester, rayon (in combination with other fibers), cotton, acrylic fiber and the like and combinations thereof. Preferably, the primary layer 12 has a basis weight in the range of about 10 gsm to about 75 gsm. Bi-component fibers may be made up of a polyester layer and a polyethylene sheath. Using a fusible fabric increases the ease with which the primary layer 12 may be mounted to any underlying layer should such an underlying layer be employed. According to another aspect of the invention the porous primary layer 12 is constructed from a microporous polymeric film material.
According to one aspect of the invention, the porous primary layer 12 is provided with the fragrance 18. The fragrance 18 may be selected from one of the fragrances set forth in Table 1 above or may be selected from other common fragrances known to those of skill in the art. The fragrance 18 may also constitute a complex fragrance, i.e. a fragrance including a mixture of a number of different fragrance components. Typically the solubility parameter δf of such complex fragrance mixtures may be obtained from the commercial manufacturer of such fragrances. The fragrance 18 is preferably provided on or in the primary layer 12 in an amount greater than about 3 gsm (g/m2), preferably between about 3 gsm and about 15 gsm.
According to one aspect of the invention, the bottom surface 16 of the porous primary layer 12 is provided with a positioning adhesive 20. Preferably the positioning adhesive 20 is applied to the bottom surface 16 in an amount between about 8 gsm to about 25 gsm. Suitable positioning adhesive 20 compositions include hot melt adhesives based on block copolymers such as linear or radial co-polymer structures having the formula (A-B)x wherein block A is a polyvinylarene block, block B is a poly(monoalkenyl) block, and x is an integer greater than or equal to one that denotes the number of polymeric arms. Suitable block A polyvinylarenes include, but are not limited to, polystyrene, polyalpha-methylstyrene, polyvinyltoluene, and combinations thereof. Likewise, suitable Block B poly(monoalkenyl) blocks include, but are not limited to, conjugated diene elastomers, such as polybutadiene, polyisoprene, and hydrogenated elastomers such as ethylene butylenes, ethylene propylene, polyisobutylene, or combinations thereof. Commercial examples of these types of block copolymers include Kraton™ elastomers from Kraton Polymers L.P, Vector™ elastomers from Dexco, SIBSTAR polymers from Kaneka USA, and Stereon™ from Firestone Tire & Rubber Co. Alternately, suitable acrylic hot melt adhesive polymers such as the ACResin hot melt adhesives from BASF Corp. may also be used. In addition to providing some level of insolubility to the fragrances, these systems can be rendered further insoluble via crosslinking using a UV radiation source.
According to the present invention, the positioning adhesive 20 and the fragrance 18 should be selected such that they have a solubility parameter absolute value difference of greater than 1.5, preferably greater than 3.0 and most preferably greater than 5.0. This relationship can be expressed by the follow equation:
|δpa−δf|>1.5; where
Referring to
The construction adhesive 35 is preferably selected from the same group of adhesives as the positioing adhesive 20. Thus suitable construction adhesive 35 compositions include hot melt adhesives based on block copolymers such as linear or radial co-polymer structures having the formula (A-B)x wherein block A is a polyvinylarene block, block B is a poly(monoalkenyl) block, and x is an integer greater than or equal to one that denotes the number of polymeric arms. Suitable block A polyvinylarenes include, but are not limited to, polystyrene, polyalphamethylstyrene, polyvinyltoluene, and combinations thereof. Likewise, suitable Block B poly(monoalkenyl) blocks include, but are not limited to, conjugated diene elastomers, such as polybutadiene, polyisoprene, and hydrogenated elastomers such as ethylene butylenes, ethylene propylene, polyisobutylene, or combinations thereof. Commercial examples of these types of block copolymers include Kraton™ elastomers from Kraton Polymers L.P, Vector™ elastomers from Dexco, SIBSTAR polymers from Kaneka USA, and Stereon™ from Firestone Tire & Rubber Co. Alternately, suitable acrylic hot melt adhesive polymers such as the ACResin hot melt adhesives from BASF Corp. may also be used. In addition to providing some level of insolubility to the fragrances, these systems can be rendered further insoluble via crosslinking using a UV radiation source.
As shown in
1.67>Aca/Af>0.333, where
According to the present invention, the construction adhesive 35 and the fragrance 18 should be selected such that they have a solubility parameter absolute value difference of greater than 1.5, preferably greater than 3.0 and most preferably greater than 5.0. This relationship can be expressed by the follow equation:
|δca−δf|>1.5; where
According to one aspect of the invention, the secondary layer 32 may be a non-porous layer. In one preferred embodiment of the invention, the secondary layer 32 is a non-porous polymeric film such as polyethylene or polypropylene film.
Alternatively, the secondary layer 32 may be a porous layer. A porous secondary layer 32 may be a nonwoven material composed of only one type of fiber, such as polyester or polypropylene or it may include a mixture of more than one fiber. The secondary layer 32 may be composed of bi-component or conjugate fibers having a low melting point component and a high melting point component. The fibers may be selected from a variety of natural and synthetic materials such as nylon, polyester, rayon (in combination with other fibers), cotton, acrylic fiber and the like and combinations thereof. Bi-component fibers may be made up of a polyester layer and a polyethylene sheath. Using a fusible fabric increases the ease with which the secondary layer 32 may be mounted to an adjacent layer, e.g. the primary layer 12. According to another aspect of the invention, the secondary layer 32 is constructed from a microporous polymeric film material.
Referring to
In the embodiment of the invention shown in
The patches 10, 10a and 10b described herein preferably have a thickness in the range of between about 0.25 mm and about 2.0 mm.
A fragrance emitting patch according to the present invention may be constructed to include a 30 gsm primary layer made from a spunlace nonwoven material and a secondary non-porous layer made from 10 gsm polyethylene film. A sytrenic block copolymer construction adhesive having a solubility parameter δca of 14.8 is applied to a bottom surface of the primary layer in an amount of 5 gsm to adhere the primary layer to the secondary layer. The bottom surface of the secondary layer is provided with a sytrenic block copolymers positioning adhesive having a solubility parameter δpa of 15. A fragrance consisting of Eugenol having a solubility parameter δf of 22.2 is applied to a top surface of the primary layer in an amount of 10 gsm. In this example, the absolute value difference of the solubility parameter of the construction adhesive and the fragrance is 7.4 and the absolute value difference of the solubility parameter of the positioning adhesive and the fragrance is 7.2. A ratio of the add on amount of construction adhesive relative to the add on amount of fragrance is 0.5.
Another fragrance emitting patch in accordance with the invention may be constructed in identical fashion to the patch described in Example #1 except that the secondary non-porous layer of example 1 is replaced with a 30 gsm layer spunlace nonwoven material.
This application claims priority to Application No. 60/974,659 filed on Sep. 24, 2007, the entire contents of which are incorporated by reference herein.
Number | Date | Country | |
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60974659 | Sep 2007 | US |