Patent Application
20050223512
The invention concerns a cosmetic cotton pad, i.e. a cotton pad for cleaning the skin or for removing make-up, as well as for applying cosmetic products such as creams, onto the skin.
There are many different types of cosmetic cotton pads. EP 1 106 723 A1 discloses e.g. a cotton pad, both surfaces of which are water-jet needled. The cotton pad may also comprise 0 to 30% of artificial fibers, such as viscose fibers, polyester fibers, or bicomponent fibers.
EP 0 836 842 B1 discloses cotton pads and the production thereof. The pads comprise hydrophilic materials such as e.g. cotton, viscose or flax and/or hydrophobic materials such as e.g. polyethylene terephtalate or polypropylene. However, cotton pads are preferred which consist of 100% cotton, which consist of 100% viscose, which have at least 25% viscose, the rest being cotton, which have at least 25% cotton, the rest being viscose, which have 50% viscose and 50% polyethylene terephtalate, or which have 50% viscose and 50% polypropylene. Water jet solidification is used to solidify the non-woven fiber material.
EP 0 405 043 B1 discloses a three-layered cotton pad, wherein the layers consist of 100% cotton noils. The two outer layers are tightly compacted and have a honeycomb pattern on their respective visible side. The three layers are combined into a sandwich-type construction. The edge regions of at least the outer layers are preferably connected to each other.
In accordance with WO 00/76384 A1, a cotton pad consists of 100% cotton fibers, wherein a first layer comprises fine fibers of a thickness of between 0.7 and 1.75 denier (2 to 5 μg/pouce) and a second layer of thicker fibers, which is to form an abrasive surface.
U.S. Pat. No. 4,100,324 describes a fiber mixture of wood pulp fibers and thermoplastic microfibers having an average fiber diameter of less than 10 μm. Due to the fact that this fiber mixture is produced quasi simultaneously with spinning of the microfibers, by e.g. introducing an air flow and a cellulose fiber flow into the region of the spinning head for the microfibers, the fibers are connected and the microfibers cause fixation of the cellulose fibers i.e. in a state in which the microfibers are still at increased temperatures and not yet hardened. The microfibers therefore form matrices for the wood pulp fibers and the wood pulp fibers are embedded in a flexible i.e. not rigid manner, even with very small microfiber contents up to less than 1 weight %. Further fibers or particulate material, including synthetic fibers such as nylon fibers and natural fibers such as cotton, flax, jute, and silk may also be used.
Due to the production of the fiber mixture quasi in situ with formation of the microfibers in the melt blown process, the microfibers lose their independence in the fiber product and are changed due to contact with the wood pulp fibers in the still molten state.
It is the object of the present invention to produce a cosmetic cotton pad which feels very soft and still has a very high cleaning or make-up removing capability.
This object is achieved in accordance with the invention with a cotton pad comprising or consisting essentially of synthetic micro staple fibers of at least 7 mm in length.
The term micro staple fibers used above means synthetic fibers having a fiber thickness of ≦1 dtex. The term micro staple fibers means that microfibers of a certain length or in a certain length range which are previously formed in a separate production method and are subsequently used for the production of the non-woven fiber material layer of the cotton pad. It has turned out that synthetic micro staple fibers can make the cotton pad softer and therefore provide excellent haptic effect for the user. Surprisingly, this is not associated with reduced cleaning or make-up removing effect. On the contrary, the inventive cotton pads having or consisting essentially of synthetic micro staple fibers of a length of at least 7 mm have superior cleaning and make-up removing properties. This may be due to the large surface area produced by the fine structure of the micro staple fibers which can come into contact with the skin surface to be cleaned. This large surface area therefore also defines a large number of micro gaps and openings which may receive impurities, skin particles or make-up.
The fiber length of the micro staple fibers which can be used is preferably 10-38 mm, in particular 15-32 mm.
In a further design of the invention, the micro staple fibers may be polyester (PES) or viscose fibers. The surface of the micro staple fibers is preferably hydrophiliated. One of the surfaces of the cotton pad may have an imprinted pattern. In this case, the imprinted pattern can be generated in a conventional manner, e.g. through calender imprint or through water jet needling as disclosed in EP-1106723-A2 or WO-99/25318-A1. Generation of the imprinted pattern can be accompanied by solidification of the non-woven material. The non-woven material can be solidified by adding thermally melting binding fibers or through the addition of chemical binders, such as e.g. aqueous polymer dispersions, e.g. polyacrylate, polyvinyl acetate, polyvinyl alcohols, latices or binders on the basis of solvents or polyurethanes or powder adhesives/fusion adhesive powder e.g. of polyamide, polyethylene, ethylene vinyl acetate, polyurethane or polyester.
The weight per unit area of the inventive cosmetic pad is preferably between 40 and 300 g/m2, in particular 60 to 250 g/m2, preferably 120-250 g/m2, and particularly preferred 150 to 250 g/m2.
For applications in which the cosmetic cotton pad is designed to absorb liquid, i.e. if it should be suitable to receive a skin-cleaning solution or for removing make-up using a make-up removing means having a high liquid portion, the cotton pad advantageously also includes up to 72 weight % of cotton fibers, in particular 15 to 65 weight % and also in particular 50 to 65 weight % of cotton fibers. Cotton noils are preferably used. The cotton pad may comprise cotton fibers which are treated with a softener of at least 0.2 weight %. This softener may comprise a fatty acid condensation product and/or functional polydimethyl siloxanes and/or polyethylenes.
In order to obtain a high internal stability for the inventive cotton pad, it is also particularly preferred to additionally include thermally melting binding fibers, preferably in an amount of 10-20 weight %, and to thermally solidify the cotton pad with these binding fibers. The portion of thermally melting binding fibers relative to the mass of the cotton pad is, in particular, 12-18 weight % and more preferred 12-15 weight %.
In a further design of the invention, the binding fibers may be multi-component fibers, in particular, bicomponent fibers having a carrier component which melts at higher temperatures and a component which melts at lower temperatures.
The multi-component fibers, in particular bi-component fibers preferably have a fiber thickness of 1.3-10 dtex, in particular 1.3-3 dtex and a fiber length of 3 to 60 mm. Core/jacket fibers or side-to-side fibers are preferably used.
The use of bicomponent fibers having a copolyester (CO-PES) as the low melting component and polyester (PES) as the component with the higher melting temperature has proven to be advantageous.
The melting point of the thermally melting binding fibers or of the low melting component (e.g. CO-PES) of the multi-component fibers is lower than the melting point of the micro staple fibers, as is of particular importance in a further design of the invention. Micro staple fibers from a polyester material could e.g. be used having a melting point of approximately 256° C. and CO-PES/PES bicomponent fibers with a melting point for the low melting component CO-PES of 110° C. and for the higher melting component PES of 255° C. In this case, thermal solidification of the non-woven fiber material could be carried out without thermally changing the higher melting component of the bicomponent fibers and the micro staple fibers.
In a further development of the invention, one side of the cotton pad has a rough surface effected by applying an abrasive in the form of a coating. This produces a cotton pad having one side which is experienced as being very soft and has a very high cleaning effect as explained above, and one rough side which is used for “peeling”, i.e. for removing dead skin particles while also providing a pleasant massaging effect.
The abrasive may preferably be formed from a thermoplastic fusion adhesive powder. The fusion adhesive powder may be disposed as a powdery component, e.g. using a precision distributor via a vibrating screen, onto one side of the cotton pad and be thermally fixed at that location. Thermal fixation is preferably effected by sintering in an oven. The fusion adhesive powder does not thereby melt, rather the particles are connected to the cotton pad by the sintering process while maintaining their particle shape to form the rough surface structure. The fusion adhesive preferably used in this case comprises polyethylene and/or polyamide and/or polyester. It has a grain size of 1-500 μm, in particular 1-100 μm, preferably 1-65 μm. It has proven to be useful and advantageous when the abrasive is applied with a weight per unit area of 5-50 g/m2, in particular 10-40 m2 and preferably 15-30 g/m2.
In a further development of the invention, the cotton pad may be wetted during manufacture and packaged in a damp state in a substantially moisture-proof manner to be sold to the end user in this form. The invention also concerns damp cloths, i.e. damp non-woven materials of the above-described inventive non-woven fiber material. Damp and dry cotton swabs can also be produced therefrom.
Damp cotton pads or damp cloths also preferably comprise cotton fibers which are or can be treated with a softener of at least 0.2 weight %, in particular of the above-described type. Damp pads are preferably wetted with an oil-in-water cleaning emulsion having a viscosity of <2000 mPas, preferably <800 mPas. The oil-in-water emulsion may comprise a portion of 0.2 to 0.5 weight % of a preservative, e.g. parabene or benzyl alcohols. 2-5 weight % of plant extracts and 0.2 to 0.5 weight % of perfume oil portion may also be contained in the oil-in-water emulsion.
The, in particular, damp cotton pads or damp cloths preferably have a low optical permeability of less than 0.9%, preferably less than 0.75%, particularly preferred less than 0.70%, and particularly preferred of less than 0.6%. The optical permeability is measured at a wavelength of 600 nm with a Perkin-Elmer Lambda 2 UV/VIS spectrophotometer on specimens of 30 mm×40 mm in size.
The optical impermeability is an indication for the packed density of the fiber material and therefore a measure of the fiber surface available for cleaning.
In accordance with the invention, the cleaning effect of a cotton pad or damp cloth, in particular a damp cotton pad, can be determined through measurement of its optical permeability thereby permitting a comparison of the cleaning effect of different cotton pads or damp cloths. Independent patent protection is therefore claimed, in particular, for a damp cotton fiber pad or damp fiber cloth having a low optical permeability of less than 0.9%, preferably less than 0.75%, particularly preferred of less than 0.70% m, particularly preferred of less than 0.6%, in dependence on the type of fibers used and of the fiber composition.
Damp cloths which are commercially available have optical permeabilities of 1.76% (Nivea Visage, Erfrischende Reinigungstücher für normale Haut und Mischhaut, Beiersdorf AG), 2.26% (Bebe Young Care Quick'n Clean für alle Hauttypen, Johnson & Johnson), 2.57% (Diadermine, Pflegende Reinigungstücher für Gesicht und Augen, für alle Hauttypen, Schwarzkopf und Henkel Laboratories Diadermine), 0.96% (Demak'up Reinigungstücher, 100% Baurnwolle, für normale und Mischhaut, Georgia Pacific).
In a preferred embodiment of the inventive damp cloths, the cloths are provided with an emulsion and have an optical permeability of 0.55% (damp cloth 1) or 0.48% (damp cloth 2). The composition of the damp cloths is given below.
Damp cloth 1: 37% PES microfibers with a fiber thickness of 0.9 dtex and a fiber length of 18 mm, 23% cotton noils, 40% viscose fibers with a fiber thickness of 1.7 dtex and a fiber length of 40 mm. The weight per unit area of the dry non-woven fiber material was 63 g/m2. The thickness of the dry non-woven fiber material was 0.66 mm, measured at a pressure of 0.5 kPa with a test surface of 25 cm2.
Damp cloth 2: 49% PES microfibers with a fiber thickness of 0.9 dtex and a fiber length of 18 mm and 51% cotton noils. The weight per unit area of the dry non-woven fiber material was 78 g/m2. The thickness of the dry non-woven fiber material was 0.80 mm, measured at a pressure of 0.5 kPa with a test surface of 25 cm2.
The damp cloths 1 and 2 were impregnated with Emulgade CM (Cognis Deutschland GmbH & Co. KG, PIT-emulsion), which is an oil in water emulsion consisting of water, cetearyl isononanoat, ceteareth 20, cetearyl alcohol, phenoxy ethanol, parabene, potassium sorbate, glycerin, perfume, citric acid, cetyl palmitate and ceteareth 12 (INCI declaration). The emulsion concentration was 7.5%. The amount of emulsion was 300% referred to the dry weight of the non-woven fiber material (i.e. 300 g of thinned emulsion to 100 g non-woven material).
To produce the inventive cotton pads, the synthetic micro staple fibers which are produced in a separate process are disposed in a conventional non-woven material forming method to form a non-woven material. If different fiber types are used, these are advantageously previously mixed in an air flow and then disposed. If thermally melting binding fibers are present, thermal fixing of the non-woven material can be performed in an “air-through-method” with a gas temperature which can be accurately adjusted, preferably without thereby thermally influencing or impairing the synthetic micro staple fibers and their structure. In an alternative or also additional manner, water jet needling of the non-woven fiber material web may be provided before or after thermal fixing. Irrespective thereof, imprint calendering on one or two sides may be used to provide the cotton pad with a surface pattern.
The inventive cotton pad is preferably compacted such that it has a longitudinal stability or maximum tensile strength in a longitudinal direction (machine direction) of 5-30 N/25 mm, in particular 10-25 N/25 mm and preferably >15 N/25 mm and a maximum tensile strength in a transverse direction (transverse to the machine direction) of 5-30 N/25 mm, in particular 8-20 N/25 m and preferably >10 N/25 mm. In the embodiment of a damp cloth, in particular the longitudinal stability or maximum tensile strength in a longitudinal direction of the damp cloth (machine direction) is advantageously 5-70 N/25 mm, preferably 10-60 N/25 mm, and with particular preference 30-50 N/25 mm and the maximum tensile strength in a transverse direction (transverse to the machine direction) is advantageously 5-60 N/25 mm, in particular 10-50 N/25 mm and preferably 20-40 N/25 mm. This maximum tensile strength may be determined using a standardized tensile testing machine in accordance with DIN 5122 using the following testing method: Samples having a clamping width of 25 mm and a clamping length of 30 mm are taken from the cotton pad to be examined, i.e. from a central region. The samples are clamped vertically in the clamping receptacles of the standardized tensile testing machine which are moved apart with a testing speed of 100 mm/min at the plane of their extension to thereby measure the tensile force acting in this direction. The maximum tensile force is the force at which the cotton pad is torn. If previously higher force peaks were measured during expansion, these represent the maximum tensile force in the sense of this procedure. For measurements in the longitudinal and transverse directions which corresponds to the machine direction or a direction transverse thereto, different, in particular five individual measurements can be taken and their average value can be calculated.
The inventive cotton pad preferably has a thickness of preferably 0.5 to 4.5 mm which is determined at a specific measuring pressure of 0.5 kPa on a 25 cm2 surface of a specimen sample. The testing method corresponds to DIN EN ISO 9073-2 (testing method for non-woven materials, determination of the thickness).
The absorptive capacity of inventive cotton pads can also be determined. Corresponding to PH. EUR. 1997, Monografie Verbandwatte aus Baurnwolle, a test of the absorptive capacity is determined by measuring the sinking time in a liquid of a wire basket filled with specimens to be tested. The wire basket which can be used in this case is a cylindrical basket of copper wire with a wire diameter of 0.4 mm. The height is 80 mm, the diameter 50 mm, the mesh width 15-20 mm and the mass 2.7+/−0.3 g. Moreover, a beaker of a diameter of 11-12 cm is used.
The cotton pads to be tested are put into the wire basket until a testing amount of 5 g is obtained. The basket is previously weighed with an accuracy of 0.01 g (M1). The 5 g of specimen material constitute a mass M2. The beaker is filled with demineralized water to a level of approximately 100 mm and the filled basket is dropped onto the water from a height of 10 mm. The time needed to sink below the surface is measured with a stop watch. Directly after determination of the sinking time, the basket is lifted out of the water and is horizontally held along its longitudinal axis for 30 s of dripping time. After lapse of the dripping time, the basket is put into a counterbalanced beaker (M3) and weighed with an accuracy of 0.01 g (M4).
The water retaining capacity is given by:
The sinking time and the water retaining capacity are given as an average value of three measurements. The sinking time of preferred cotton pads is maximally 15 sec and the water retaining capacity is at least 10 g/g. This can be adjusted through the portion of absorbing fibers and/or through the addition of hydrophiliation agents.
Further features, details and advantages of the invention can be extracted from the following claims and the figure and the following description of one preferred embodiment of the invention.
Two preferred compositions of the inventive cotton pads are shown below: They are indicated with PH and PH*.
The cotton pads PH and PH* were obtained by mixing previously produced micro staple fibers having a fiber thickness of 0.9 dtex and a fiber length of approximately 18 mm with cotton noils and the bicomponent fibers in an air flow in the respective weight percentage compositions. The micro staple fibers are polyester fibers with a melting point of 256° C. The bicomponent fibers are core jacket fibers with a polyester core component having a higher melting point of 255° C. and a jacket of a copolyester (CO-PES) with a melting point of 110° C. The length of these bicomponent fibers is 51 mm and their thickness is 1.35 dtex.
These cotton pads were compared with comparable products, wherein the following examination of the cleaning and make-up removing effect was carried out: Make-up was disposed on a substrate to determine, under standardized conditions, how the respective cotton pads remove make-up from that substrate. Towards this end, a tensile testing machine (DIN 51221, class 1) was used. The substrate was “smooth beige goat leather for the production of shoes”. 0.1 g of a protecting cream make-up (Nivea Beauté Teint Natur Intensive) was uniformly deposited onto a piece of this smooth goat leather having a size of 30×100 mm and left to dry for 2 to 2½ hours.
To carry out the examination, circular blotting paper (Schleicher & Schüll, Nr. 860) having a diameter of 57 mm (the same size as the cotton pad to be tested which also has a diameter of 57 mm) was punched out and soaked with 0.85-0.9 g demineralized water. The round cotton pad (specimen) (diameter 57 mm, 25.5 cm2) is disposed on the soaked blotting paper and loaded for 10 s with 1 kg. The cotton pad thereby absorbs some liquid. The cotton pad with moistened surface is then disposed on the goat leather in front of the location with “make-up”. A cylindrical weight of 300 g, a diameter of 57 mm, and having a lug is connected to the tensile device of the tensile testing machine using a string. The connected weight is fixed using two-sided sticky tape so that it exactly covers the cotton pad. The cotton pad and the weight are then drawn over the “make-up” surface at a speed of 200 mm/min. At least five make-up removing tests are carried out and the amount of make-up remaining on the goat leather is judged visually or using a color measuring device (chromameter). The above-described cotton pads PH and PH* and a cotton pad which consists of 100 weight % cotton, PH 100% cotton are used as specimens, wherein the latter is available under the trademark “Labell” and is solidified through water jets. Moreover, a cotton pad of the available trademark “Demak'up Duo” and of the trademark “Demak'up Supersoft” were examined which also consist of 100% cotton and is solidified through water jets. Cotton pads of the trademarks “Nivea” and “Jean Carol” each consist of 100% cotton and are also water-jet solidified. A cotton pad imprinted on both sides (trademark “Hydra”) was also tested.
One can see that the products PH and PH* achieved a much more effective cleaning action or make-up removing effect compared to the comparable products.
A comparison of the inventive products PH and PH* shows that the increase in the microfiber portion improves the make-up removing effect.
The imprint lines 10 forming the honeycombs and the imprint pattern 4 are wavy having a half wavelength g of 2-8 mm, in particular 3-5 mm and a wavelength height h of 0.5-2 mm, in particular 0.8-1.2 mm.
| Number | Date | Country | Kind |
|---|---|---|---|
| 02400033.3 | Jul 2002 | EP | regional |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/EP03/07629 | 7/15/2003 | WO | 11/12/2004 |
