Cosmetic Sheet Masks For Improved Product Delivery

Abstract

Nonwoven fabrics may be fashioned as topical delivery systems with increased and controllable rate of product release, while still possessing the requisite strength and durability for mass production and distribution. Such delivery systems comprise fabrics that are fashioned from micro-denier fibers that are produced by fibrillating bicomponent island-in-the-sea fibers. Facial masks made from these fabrics can achieve adequate product delivery in 3-5 minutes or less.

Claims

1. An island-in-the sea nonwoven fabric made from bicomponent island-in-the-sea fibers, wherein: the bicomponent island-in-the sea fibers comprise: an island fiber made from a first polymeric material; a sea fiber made from a second polymeric material; and the sea and island fibers are entangled by water-jetting with a jet-to-jet spacing of 600.Math.-2400.Math..

2. An island-in-the sea nonwoven fabric according claim 1 wherein: 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 the first polymeric material is polypropylene and the second polymeric material is polylactic acid.

3. An island-in-the sea nonwoven fabric according claim 1 wherein: the first polymeric material, second polymeric material or both are selected from polyvinyl alcohol, polybutylene succinate, recycled polyethylene, recycled polypropylene, recycled polyester, copolyester, polyethylene derived from sugarcane, and polyamide derived from castor oil.

4. An island-in-the sea nonwoven fabric according claim 1 wherein the weight ratio of the first polymeric material to the second polymeric material is between 1:4 and 1:6.

5. An island-in-the sea nonwoven fabric according claim 1 wherein the fiber packing density of the nonwoven fabric is 5% - 30%.

6. An island-in-the sea nonwoven fabric according claim 1 wherein the island and sea fibers are micro-denier fibers, and the basis weight of the fabric is 30 g/m.sup.2 - 100 g/m.sup.2.

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

8. A sheet mask according to claim 7, wherein the water-jetting is carried out with a jet-to-jet spacing of 600 .Math.-2400 .Math..

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

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

11. A sheet mask according to claim 9 that is constructed as a full facial mask.

Description

DETAILED DESCRIPTION

[0015] We have discovered that certain fabrics made from micro-denier fibers are particularly useful in the area of topical delivery, especially cosmetic sheet masks, for improved product delivery. We describe a customized island-in-the-sea process to produce fabrics with certain defined parametric values. Particularly advantageous combinations of polymeric materials (island component/sea component) for the applications described herein include: polyamide 6 / polylactic acid; polyamide 6/ polyethylene; polypropylene / polylactic acid, although the invention is not limited to these combinations. In preferred embodiments of the invention the weight ratio of island component polymer to sea component polymer is between about 1:4 to about 1:6. For example, the island component polymer may make-up about 15-20% by weight of the bi-component fiber, while the sea component makes-up 80-85% by weight. Our observations are that masks made from such fabrics are the superior in terms of topical delivery of fluid products. This is particularly true when the step of hydroentangling is performed using a preferred jet-to-jet spacing. Preferred jet-to-jet spacing ranges from about 600 .Math. - 2400 .Math., with a water pressure of 10 bars to1,000 bars If the jet-to-jet spacing is less than about 600 .Math., then the resulting fabric is too thin and too dense to release liquid product efficiently, so that a full dose of product may not be delivered in less than 10 minutes. On the other hand, if the jet spacing is greater than about 2400 .Math., then the fibers might separate so that the fabric loses mechanical integrity. With the preferred island-to-sea ratio and preferred jet-to-jet spacing, we have noticed a “sweet spot” where the fabric maintains mechanical integrity that is sufficient for the applications contemplated herein, while still being able to release liquid product efficiently. Fabrics produced within this sweet spot have a basis weight of about 30 g/m.sup.2 - 100 g/m.sup.2, preferably about 80 g/m.sup.2 - 100 g/m.sup.2. Nonwoven fabrics made according to the present invention also possess a unique “quilted” structure, which provides a visual differentiation from fabrics made by other methods.

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

[0017] When the application is a cosmetic sheet mask, for delivering a liquid composition to a skin surface, then the mask is impregnated with the liquid composition. Given the packing density specified above, the weight of liquid composition that may be impregnated into the mask typically ranges from 2 to 8 times the weight of the mask. At the same time, the specified packing density enables rapid transfer of product to a target surface. Thus, we are able to produce a cosmetic sheet mask that delivers a dose of product to a target surface in 3-5 minutes or less. As noted above, it is not uncommon that the suggested leave-on duration is 10 to 30 minutes, for cosmetic sheet masks currently on the market. That is the amount of time necessary to transfer a full dose of product to the skin surface. In contrast, we have discovered that a cosmetic sheet mask made from an island-in-the-sea nonwoven fabric, using the parameters specified herein, can achieve similar or superior results in 3-5 minutes, preferably in as little as 3 minutes, while achieving the requisite strength and durability for mass production, distribution and use of the mask.

[0018] Optionally, one or both of the island and sea components may 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 may be made from biobased materials, rather than fossil derived materials. Such materials include, for example, polyethylene derived from sugarcane, and polyamide derived from castor oil. Fabrics made from biobased materials, especially disposable items like cosmetic sheet masks, are better for the environment, and long term sustainability, in general.

[0019] Cosmetic sheet masks (including patches) according to the present invention may be made by impregnating the island-in-the-sea nonwoven fabric with one or more skin care formulations for treating the skin. In accordance with the packing density noted above, the total weight of the one or more formulations that may be impregnated into ta sheet mask typically ranges from 2 to 8 times the weight of the mask. Impregnating the sheet mask may be accomplished by any suitable means known in the art. Such cosmetic sheet masks may be used to treat various skin conditions. The sheet masks may be constructed to conform to a predetermined treatment area of the skin of a user, such as the face, neck, abdomen, or limbs or any portion thereof. For example, a full facial mask will typically extend from the hair line of the forehead to the chin, and from ear to ear, and be provided with apertures for the eyes, nose and mouth. Partial facial masks may be shaped to apply to the under eye area, or to the area lateral to the eyes, where crows feet develop, around the mouth where frown lines develop, or the T-zone of the nose. The exact size and shape of the cosmetic sheet will depend upon the intended use and product characteristics. The cosmetic sheets will have sufficient flexibility, and a size and shape adapted to conform to the desired treatment area of the user’s skin. When the sheet masks are applied to and conformed to the contour of the skin, they can deliver to the skin a pre-determined dosage of one or more skin care formulations for treating the skin.

[0020] The formulation may comprise one or more skin benefit agents. 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 depigmentation agents; anti-inflammatory agents; anti-acne agents; DNA repair agents; skin lipid barrier repair agents; anti-cellulite agents; wound-healing agents; stretch-mark/scar removing agents; plumping agents; hair growth retardation agents; hair growth stimulating agents; dark circle reduction or de-puffing agents; collagen synthesis or blood circulation enhancing agents; antioxidants; sebum-controlling agents; and pore-minimizing agents. The skin benefit agents may be either 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, palmitoyl oligopeptide, palmitoyl tetrapeptide-7, Quercus suber extract, and the like. Exemplary anti-aging agents include, but are not limited to, teprenone, trisodium resveratrol triphosphate, Polygonum cuspidatum root extract, whey protein, and the like. Exemplary moisturizing agents include, but are not limited to, hyaluronic acid, glycerin, urea, trehalose, and the like. Exemplary skin-whitening or depigmentation 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, and the like. Exemplary anti-inflammatory agents include, but are not limited to, spike moss extract, seal whip extract, Polygonum cuspidatum root extract, and the like. Exemplary anti-acne agents include, but are not limited to, salicylic acid, glycolic acid, lactobionic acid, and the like. Exemplary DNA repair agents include, but are not limited to, C1-C8 alkyl tetrahydroxycyclohexanoate, micrococcus lysate, bifida ferment lysate, and the like. 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, soybean protein, and the like. Exemplary plumping agents include, but are not limited to, Saccharomyces/xylinum black tea ferment, Anemarrhena asphodeloides root extract, sodium hyaluronate, and the like. Exemplary hair growth retardation 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-puffying agents include, but are not limited to, hesperidin methyl chalcone, dipeptide-2, Passiflora incarnate flower extract, linoleic acid, isolinoleic acid, and the like. Exemplary collagen synthesis or blood circulation enhancing agents include, but are not limited to, arginine, Ascophyllum nodosum extract, Asparagopsis armata extract, caffeine, and the like. Exemplary anti-oxidants include, but are not limited to, nordihydroguaiaretic acid, grape seed extract, green tea leaf extract, and the like.