Cosmetic sheet masks for improved product delivery

Abstract

Nonwoven fabrics can be made as topical delivery systems with increased and controllable product release rates while still possessing the strength and durability necessary for mass production and distribution. Such delivery systems include fabrics made from microdenier fibers produced by fibrillating bicomponent islands-in-the-sea fibers. Facial masks made from these fabrics can achieve adequate product delivery within 3-5 minutes.

Description

[Technical field]

[0001] The present invention relates to nonwoven fabrics and their use as topical delivery systems for beauty and personal care products. More specifically, the present invention relates to sheet masks (including patches) made from the nonwoven fabrics. [Background technology]

[0002] Cosmetic and personal care sheet masks are popular for delivering products to the face and other areas of the body. Typically, the suggested leave-on period for sheet masks is 10-30 minutes. This time is required to transfer a significant dose of the product impregnated in the mask to the skin. Also, the user may experience a pleasant cooling sensation while the mask is on the skin. However, having to wear a sheet mask, such as a facial mask, for 10-30 minutes can be inconvenient for busy consumers who would get the most benefit from a sheet facial mask in a much shorter time. Furthermore, the release rate of the product from a conventional sheet mask generally does not match the rate of absorption by the skin. When the unabsorbed product is exposed to the surrounding atmosphere, degradation occurs, such as evaporation loss. As a result of this, excess product is typically impregnated into the mask to ensure that the user receives an adequate dose. This increases costs and waste. For these and other reasons, there remains a need for cosmetic sheet masks that can deliver a dose of aqueous product in significantly less than 10 minutes. The release rate of aqueous products from sheet fabrics is highly dependent on the porosity of the fabric. Generally, when fiber density and / or fiber size are reduced, porosity (and release rate) increases, but the integrity of the fabric made from these smaller fibers is compromised and may not have the necessary strength and durability.Therefore, one problem addressed by the present invention is how to make the cosmetic sheet mask with increased and controllable release rate while still having the necessary strength and durability for mass production and distribution.

[0003] Different fabrics used in making cosmetic sheet masks have different fluid handling properties, such as the amount of fluid formulation that the fabric can hold, the rate of release to the skin, and evaporation loss. These properties also depend on the arrangement (structure) of fibers within a given fabric. For example, cellulosic fabrics (such as cotton and rayon) can absorb as much as eight times their mass, while polyester (PET) fabrics can only hold one or two times their mass. In cellulosic fabrics, fluid resides in the spaces (pores) between the fibers of the fabric and in the pores of the individual fibers. In polyester fabrics, fluid cannot penetrate individual fibers, but resides only in the spaces (pores) between the fibers.

[0004] Another class of fabrics is nonwovens. Nonwovens are arrangements of fibers bonded together by entangling the fibers by any of several means including mechanical, thermal, and chemical. Nonwoven materials can be in the form of webs, mats, batts, and sheets. The properties of nonwoven materials depend, in part, on the selection of raw materials and the processes of web formation, bonding, and finishing. U.S. Patent No. 3,338,992 is an example of an early attempt to produce nonwoven webs from continuous synthetic fibers. As used herein, a "fiber" is a structure that has a high aspect ratio (length / diameter). Although there is no universal agreement, we use the definition of "microfiber" as a material that has a diameter of about 0.5 to 5μ and a linear mass density of less than 1 denier (denier is defined as the grams of fiber per 9000 meters). "Nanofibers," which we define as having a diameter of less than about 0.5μ, have a relatively high surface area to volume ratio and high porosity compared to microfibers. "Microdenier" fiber means a fiber less than 1 denier. "Staple fiber" refers to a relatively short, fixed length fiber, while "filament fiber" is a longer, effectively continuous fiber with a very high aspect ratio.

[0005] There are various techniques for producing the fibers that ultimately make up the nonwoven fabric. "Multicomponent fibers" are produced from two or more materials, such as different synthetic polymers. Fabrics made from multicomponent fibers benefit from having properties from each of the individual fiber components. Alternatively, after the multicomponent fibers are produced, it is sometimes useful to separate the component fibers from each other for individual processing. Microdenier fibers are commonly produced in this manner. Common separation techniques can be classified as mechanical or solvent-based (e.g., dissolving one type of fiber and leaving the other behind, or swelling the fibers to separate them).

[0006] A "bicomponent fiber" is composed of two polymers of different chemical and physical properties. Typically, the two polymers are coextruded from the same spinneret to form a single filament, and the two polymers are bounded along a fine interface. The parameters required to successfully process two different starting materials in this manner (e.g., polymer fluid viscosity, drawability, compatibility with spinning methods) are known in the art. Several geometries of bicomponent fibers are common. Some of these are known in the art as side-by-side, segmented pie, segmented ribbon, segmented cross, tipped-trilobal, side-by-side bow-tie, core-sheath, and islands-in-the-sea. The present invention uses islands-in-the-sea fabrics made by a specific technique.

[0007] In general, islands-in-the-sea fibers contain many small filaments of one polymer (the islands) arranged in a matrix of another polymer (the sea). US Patent No. 6,455,156 discloses one technique for making this type of bicomponent fiber. However, in this process, an alkaline solution must be used to dissolve the sea matrix in order to reach the island fibers (which are not adversely affected by the alkaline solution). The use of environmentally unfriendly alkaline solutions is a drawback of this method, while it limits the polymers that can be used for the island components to those that are not adversely affected by the alkaline solution.

[0008] Nos. 7,981,226 and 8,420,556 (incorporated herein by reference in their entirety) disclose a method for making high strength, high surface area nonwoven fabrics by fibrillating bicomponent fibers from microdenier islands-in-the-sea fibers. As a result, the island components are released from the sea matrix. In general, the sea component is weak enough to be able to fibrillate by hydroentanglement, and the island and sea components should have little or no affinity for each other. That is, they should be incompatible. Incompatibility is defined as "two fiber components that form a distinct interface between them such that one does not diffuse into the other." However, as explained in '226 and '556, "an important feature of the present invention is that the sea fibers are intertwined and entangled with the island fibers during fibrillation. As a result, island fibers can be produced at the micro- and nano-level, but the sea component also separates between each fiber [to] form micro- and nano-fibers of the sea component. Thus, the sea and island fibers produce continuous micro- and nano-fibers from a single bicomponent fiber. Also, while the fibers maintain their structural integrity, they can be intertwined and entangled with each other to form high strength fibers."

[0009] As further explained in U.S. Patent Nos. 7,981,226 and 8,420,556, prior to fibrillation, the outer fibers encapsulate the inner fibers, so that the inner fibers solidify before the outer fibers solidify. This promotes unusually strong island fibers, which can then be separated from the sea fibers by fibrillation or other external energy. In this process, both the inner island fibers and the outer sea fibers remain as continuous fibers, and bonds are then formed between the various fibers. "This promotes the high strength aspect of the invention, even at the micro and nano level, of each fiber itself."

[0010] US Patent Nos. 7,981,226 and 8,420,556 also disclose that it is preferred when the external energy for fibrillation is provided in the form of a hydroentanglement process with water jets. For this to work, both the inner island and outer sea fibers must be insoluble in water. For this reason, PVA, a material commonly used in traditional islands-in-the-sea fiber constructions, is not useful when hydroentanglement is used or when the fibers are used in fabrics for wet applications. Hydroentanglement is usually performed with bicomponent fibers on a web and can result in microdenier fibers of about 0.5 microns or less. The filament fibers thus produced can be incorporated into nonwoven fabrics that can be formed by spunbonding. Alternatively, the staple fibers may be formed into a web and bonded by any one of several known means. The nonwoven fabrics thus produced are said to be useful for making tents, parachutes, outdoor fabrics, house wraps, awnings, filters, wipes, cleaning cloths, and textiles. According to '226 and '556, the island and sea fibers may include thermoplastic polymers such as nylon 6, nylon 6 / 6, nylon 6,6 / 6, nylon 6 / 10, nylon 6 / 11, nylon 6 / 12, polypropylene, polyethylene, polyesters, copolyesters, copolyetherester elastomers, polyolefins, polyacrylates, and thermoplastic liquid crystal polymers. The thermoplastic polymers may also include copolyetherester elastomers having long chain etherester units and short chain ester units joined head to tail through ester linkages.

[0011] To the best of the inventors' knowledge, a nonwoven fabric as described below has never been used to manufacture a cosmetic or personal care sheet mask with rapid release of the product to the skin. Summary of the Invention [Problem to be solved by the invention]

[0012] The primary objective of the present invention is a topical delivery system, such as a cosmetic or personal care sheet mask, that has increased and controllable release rates while still possessing the strength and durability necessary for mass production and distribution.

[0013] Another object of the present invention is to provide a topical delivery system, such as a cosmetic or personal care sheet mask, that can achieve sufficient product delivery within 10 minutes, such as within 3 to 5 minutes. [Means for solving the problem]

[0014] We describe nonwoven topical delivery systems, such as cosmetic or personal care sheet masks, for improved product delivery. These topical delivery systems include fabrics made from microdenier fibers produced by fibrillating bicomponent islands-in-the-sea fibers. Fibrillation is achieved by hydroentanglement using jet strips with spacing between jets ranging from 600μ to 2400μ. The fiber materials and other related parameters are selected to provide a durable topical delivery system with a controllable release rate of the product. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] The inventors have discovered that certain fabrics made from microdenier fibers are particularly useful in the field of topical delivery, especially cosmetic sheet masks, for improved product delivery. The inventors describe a customized islands-in-the-sea process for producing fabrics with certain defined parameter values. Particularly advantageous combinations of polymeric materials (island / sea) for the applications described herein include polyamide 6 / polylactic acid, polyamide 6 / polyethylene, polypropylene / polylactic acid, but the invention is not limited to these combinations. In a preferred embodiment of the invention, the weight ratio of island polymer to sea polymer is about 1:4 to about 1:6. For example, the island polymer may constitute about 15-20% by weight of the bicomponent fiber, while the sea polymer constitutes 80-85% by weight. The inventors have observed that masks made from such fabrics are superior for topical delivery of fluid products. This is especially true when the step of hydroentanglement is performed with a preferred interval between jets. The preferred interval between jets is in the range of about 600μ to 2400μ, with a water pressure of 10 bar to 1,000 bar. If the interval between jets is less than about 600μ, the resulting fabric may be too thin and dense to efficiently release the liquid product, and the full dose of the product may not be delivered in less than 10 minutes. On the other hand, if the interval between jets is more than about 2400μ, the fibers may separate and the fabric may lose mechanical integrity. With the preferred island-to-sea ratio and the preferred interval between jets, the inventors have noticed a "sweet spot" where the fabric can still efficiently release the liquid product while maintaining mechanical integrity sufficient for the applications contemplated herein. Fabrics produced within this sweet spot have a weight of about 30 g / m 2 ~100g / m 2 , preferably about 80 g / m 2 ~100g / m 2 Nonwoven fabrics made according to the present invention also have a unique "quilted" structure that visually distinguishes them from fabrics made by other methods.

[0016] Fiber packing density (also known as solid volume fraction) is also important. Fiber packing density is the ratio of the volume occupied by the fibers to the volume of the fabric. The preferred fabrics of the present invention have a fiber packing density of about 5% to 30%, which means that the majority of the sheet is empty space. Nevertheless, when all other parameters are specified herein, the resulting fabric is strong and durable enough for the applications contemplated herein.

[0017] When the application is a cosmetic sheet mask for delivering a liquid composition to the skin surface, the mask is impregnated with the liquid composition. Considering the above packing density, the weight of the liquid composition that can be impregnated into the mask is typically in the range of 2 to 8 times the weight of the mask. At the same time, the specified packing density allows for rapid transfer of the product to the target surface. Thus, the present inventors can manufacture a cosmetic sheet mask that delivers a dose of the product to the target surface within 3 to 5 minutes. As mentioned above, for cosmetic sheet masks currently on the market, it is not uncommon for the proposed leaving period to be 10 to 30 minutes. This is the amount of time required to transfer the entire dose of the product to the skin surface. In contrast, the present inventors have discovered that, using the parameters specified herein, a cosmetic sheet mask made from an islands-in-the-sea type nonwoven fabric can achieve similar or superior results in 3 to 5 minutes, preferably as little as 3 minutes, while achieving the strength and durability required for mass production, distribution, and use of the mask.

[0018] Optionally, one or both of the island and sea components can be made from sustainable materials. Examples of useful sustainable materials include polyvinyl alcohol, polybutylene succinate, recycled polyethylene, recycled polypropylene, recycled polyester, or copolyester. Optionally, one or both of the island and sea components can be made from bio-based materials rather than fossil-derived materials. Such materials include, for example, polyethylene derived from sugar cane and polyamide derived from castor oil. Fabrics made from bio-based materials, especially disposable items such as cosmetic sheet masks, are generally better for the environment and long-term sustainability.

[0019] Cosmetic sheet masks (including patches) according to the present invention can be made by impregnating an islands-in-the-sea nonwoven fabric with one or more skin care formulations for treating the skin. In accordance with the above-mentioned packing density, the total weight of one or more formulations that can be impregnated into the sheet mask typically ranges from 2 to 8 times the weight of the mask. Impregnation of the sheet mask can be achieved by any suitable means known in the art. Such cosmetic sheet masks can be used to treat various skin conditions. The sheet masks can be constructed to fit a predetermined treatment area of ​​the user's skin, such as the face, neck, abdomen, or extremities, or any part thereof. For example, full face masks typically extend from the hairline on the forehead to the chin and from ear to ear, and are provided with openings for the eyes, nose, and mouth. Partial face masks can be shaped to apply to the area under the eyes, or the area beside the eyes where crow's feet occur, around the mouth where facial wrinkles occur, or the T-zone of the nose. The exact size and shape of the cosmetic sheet depends on the intended use and product properties. The cosmetic sheets have sufficient flexibility and a size and shape adapted to fit the desired treatment area of ​​the user's skin. When the sheet masks are applied and conformed to the contours of the skin, they can deliver a predetermined dosage of one or more skin care formulations to the skin for treating the skin.

[0020] The formulation may include one or more skin benefit agents. The skin benefit agents may be selected from the group consisting of anti-wrinkle or skin tightening agents, anti-aging agents, moisturizing agents, skin whitening or depigmenting agents, anti-inflammatory agents, anti-acne agents, DNA repair agents, skin lipid barrier repair agents, anti-cellulite agents, wound healing agents, stretch mark / scar removal agents, thickening agents, hair growth retardants, hair growth stimulators, dark circle reduction or de-puffiness agents, collagen synthesis or blood circulation promoters, antioxidants, sebum control agents, and pore minimizing agents. The skin benefit agents may be charged or neutral. Exemplary anti-wrinkle agents include, but are not limited to, acetyl hexapeptide-8, palmitoyl oligopeptide, dipeptide diaminobutyroyl, benzylamide diacetate, and the like. Exemplary skin tightening agents include, but are not limited to, algae extract, pullulan, sweet almond seed extract, carbomer, palmitoylated oligopeptide, palmitoylated tetrapeptide-7, Quercus suber extract, etc. Exemplary anti-aging agents include, but are not limited to, teprenone, trisodium resveratrol triphosphate, Polygonum cuspidatum root extract, whey protein, etc. Exemplary moisturizing agents include, but are not limited to, hyaluronic acid, glycerin, urea, trehalose, etc. Exemplary skin lightening or depigmenting agents include, but are not limited to, ascorbic acid, magnesium ascorbyl phosphate, aminopropyl ascorbyl phosphate, mulberry root extract, Scutellaria baicalensis extract, grape extract, ferulic acid, hinokitol, etc. Exemplary anti-inflammatory agents include, but are not limited to, selaginella extract, seal whip extract, Polygonum cuspidatum root extract, etc. Exemplary anti-acne agents include, but are not limited to, salicylic acid, glycolic acid, lactobionic acid, etc. Exemplary DNA repair agents include, but are not limited to, C1-C8 alkyl tetrahydroxycyclohexanoates, micrococcus lysate, bifida ferment lysate, etc.Exemplary skin lipid barrier repair agents include, but are not limited to, phytosphingosine, linoleic acid, cholesterol, and the like. Exemplary anti-cellulite agents include, but are not limited to, Coleus forskohlii root extract, Magnolia grandiflora bark extract, Nelubo nucifera leaf extract, and the like. Exemplary wound healing agents include, but are not limited to, Mimosa tenuiflora bark extract, soy protein, and the like. Exemplary bulking agents include, but are not limited to, Saccharomyces / xylinum black tea ferment, Anemarrhena asphodeloides root extract, sodium hyaluronate, and the like. Exemplary hair growth retarding agents include, but are not limited to, ursolic acid, phytosphingosine, Boswella serrata extract, and the like. Exemplary hair growth stimulating agents include, but are not limited to, Serenoa serrulata fruit extract, licorice extract, acetyl glucosamine, and the like. Exemplary dark circle reduction or de-puffiness agents include, but are not limited to, hesperidin methyl chalcone, dipeptide-2, Passiflora incarnate flower extract, linoleic acid, isolinoleic acid, etc. Exemplary collagen synthesis or blood circulation promoters include, but are not limited to, arginine, Ascophyllum nodosum extract, Asparagopsis armata extract, caffeine, etc. Exemplary antioxidants include, but are not limited to, nordihydroguaiaretic acid, grape seed extract, green tea leaf extract, etc.

Claims

1. 1. An islands-in-the-sea nonwoven fabric made from bicomponent islands-in-the-sea fibers, The bicomponent islands-in-the-sea fiber is an island fiber made from a first polymeric material; and sea fibers made from a second polymeric material; The islands-in-sea type nonwoven fabric is formed by entangling the sea fibers and the island fibers by spraying water at intervals between sprays of 600μ to 2400μ.

2. the first polymeric material is polyamide 6 and the second polymeric material is polylactic acid; or the first polymeric material is polyamide 6 and the second polymeric material is polyethylene; or 2. The islands-in-the-sea nonwoven fabric of claim 1, wherein the first polymeric material is polypropylene and the second polymeric material is polylactic acid.

3. 2. The islands-in-the-sea nonwoven fabric of claim 1, wherein the first polymeric material, the second polymeric material, or both are selected from polyvinyl alcohol, polybutylene succinate, recycled polyethylene, recycled polypropylene, recycled polyester, copolyester, polyethylene derived from sugar cane, and polyamide derived from castor oil.

4. 2. The islands-in-the-sea nonwoven fabric of claim 1, wherein the weight ratio of the first polymeric material to the second polymeric material is from 1:4 to 1:

6.

5. 2. The islands-in-the-sea type nonwoven fabric of claim 1, wherein the fiber packing density of the nonwoven fabric is from 5% to 30%.

6. The sea fiber and the island fiber are microdenier fibers, and the basis weight of the fabric is 30 g / m ２ ~100g / m ２ 2. The islands-in-the-sea type nonwoven fabric according to claim 1 ,

7. A sheet mask for delivering a liquid composition to a skin surface, the sheet mask comprising an islands-in-the-sea nonwoven fabric made from bicomponent islands-in-the-sea fibers; The bicomponent islands-in-the-sea fiber is an island fiber made from a first polymeric material; and sea fibers made from a second polymeric material; The sea fibers and the island fibers are entangled by water injection, The sheet mask, wherein the nonwoven fabric is impregnated with the liquid composition.

8. The sheet mask according to claim 7, wherein the water jets are performed at intervals between jets of 600μ to 2400μ.

9. 8. The sheet mask according to claim 7, wherein the nonwoven fabric is constructed to conform to a predetermined treatment area of ​​a user's skin, such as the face, neck, abdomen, limbs, or any portion thereof.

10. 10. The sheet mask according to claim 9, wherein the weight of the liquid composition in the nonwoven fabric is 2 to 8 times the weight of the nonwoven fabric.

11. 10. The sheet mask according to claim 9, which is constructed as a full face mask.

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