BR112017014613B1 - CLEANING SHEET - Google Patents

Abstract

Provided is a cleaning sheet which is good in surface side texture and can exert cleaning performance on both the front surface side and the back surface side. A cleaning sheet (1) having a front surface layer (2) that is primarily composed of long fibers (4) having an average fiber diameter of 10 µm or less and having moisture absorbency and a back surface layer (3) ) which is mainly composed of short fibers (5) having an average fiber diameter of more than 10 µm, characterized in that the long fibers (4) spread evenly in a net-like shape with arcs forming irregularities in the front surface layer ( 2), multiple openings (80) which are matched in the first direction (X) and being formed in the back surface layer (3), and the long fibers (4) crossing at least some of the openings (80).

Description

[Technical Field]

[0001] The present invention relates to a cleaning sheet, and more particularly relates to a cleaning sheet used for cleaning in a dry state and a moistened state.

[Background]

[0002] Cleaning sheets including microfibers with an average fiber diameter of 0.01 mm or less have been conventionally known. For example, LPT 1 shows a cleaning sheet formed of a front surface layer including microfibers obtained by split conjugate fibers and a back surface layer including hydrophilic fibers having a larger average fiber diameter than microfibers.

[Citation List] [Patent Literature]

[0003] LPT 1: Japanese Patent No. 3944526

[Invention Summary]

[0004] When the cleaning sheet described above is used in a dry or wet state as a sheet for cleaning sebum and cosmetic dirt on a wearer's face (a), the front surface layer formed of microfibers is brought into direct contact with the user's skin. This can penetrate the microfibers in the skin pores to scrape off sebum and cosmetic dirt, and thus the sheet provides excellent cleaning performance and excellent texture with low skin irritation.

[0005] A front surface of the split conjugate fibers in the front surface layer does not have a smooth curve in a radial cross-sectional view. This could irritate sensitive skin. The back surface formed from the back surface layer including the hydrophilic fibers are less likely to function as a cleaning surface due to their softness. Thus, the back surface of the cleaning sheet selected as the cleaning surface fails to efficiently capture cosmetic dust or dirt on the face.

[0006] An object of the present invention is to provide a cleaning sheet having a front surface with excellent texture and cleaning performance on both front and rear surfaces.

[Problem Solution]

[0007] To achieve the above object, the present invention is directed to a cleaning sheet defined by a first direction and a second direction intersecting with each other, and including: a front surface layer mainly including hygroscopic long fibers with an average diameter of fiber of 0.01 mm or less, and a back surface layer primarily including short fibers having an average fiber diameter of more than 10 μl.

[0008] In the cleaning sheet according to the present invention, the casually curved long fibers form a net-like structure in the front surface layer, a plurality of harmonized openings in the first direction being formed in the back surface layer, and the long fibers crossing at least some of the openings.

[Advantageous Effects of Invention]

[0009] In the cleaning sheet according to at least one embodiment of the present invention, since the net-like structure is formed from randomly curved long fibers and having an average fiber diameter of 0.01 mm in the surface layer front, and excellent texture and brushing effect can be achieved. Also, when liquid such as cosmetic liquid is supplied, a uniform liquid film will be formed to evenly moisten the skin. Once the back surface layer has a plurality of openings harmonized in the first direction, and the back sheet being able to capture cosmetic dust and dirt from being rubbed on the skin.

[Brief Description of Drawings]

[0010] The drawings illustrate specific configurations of a cleaning sheet in accordance with the present invention including optional and preferred configurations, as well as essential features of the invention. The figures are presented as an example and not a limitation, in which: - Figure 1 is a perspective view of a cleaning sheet according to the present invention; - Figure 2 is a partially enlarged plan view of a front surface layer; - Figure 3 is a cross-sectional view taken along the line III-III in Fig. 1; - Figure 4 is a partially enlarged view of an area surrounded by a dotted chain line IV in Fig. 3; - Figure 5 is a side view schematically illustrating a main part of a manufacturing process for the cleaning sheet; - Figure 6 is a perspective view of a cosmetic sponge using the cleaning sheet according to the present invention; - Figure 7 is a cross-sectional view taken along the line VII-VII in Fig. 6; - Figures 8 and 8 (a) are perspective views of a container capable of being filled with moistened sheets; - Figure 8 (b) is an enlarged side view of a pile of sheets moistened in the container.

[Settings Description]

[0011] The configurations described below relate to a cleaning sheet illustrated in Figs. 1 to 8 including both optional and preferred features, as well as those features which are essential features of the present invention.

[0012] As illustrated in Figs. 1 and 2, the cleaning sheet 1 according to the present invention has a first X direction and a second Y direction intersecting with each other, and including a front surface 1a, a back surface 1b, a front surface layer 2 and a back surface layer 3 overlapping each other. The front surface layer 2 is formed of non-woven materials primarily including blow-spun fibers such as long hydroscopic fibers 4 having an average fiber diameter of 10 µl or less. Long fibers 4 include, for example, polyamide fibers, including nylon 6 and nylon 66, acrylic fibers, hydrophilized hydrophobic fibers. The content of the long fibers 4 in the front surface layer 2 is approximately 60% by weight or more, preferably approximately 95% by weight or more, and being 100% by weight in the present configuration.

[0013] The back surface layer 3 includes short fibers 5 including cellulosic short fibers such as hygroscopic regenerated fibers including basic rayon fibers and natural fibers with hydroscopicity including cellulose fibers, and thermoplastic synthetic fibers. The content of the staple fibers in the back surface layer 3 is approximately 50 to 100% by weight of the cellulosic staple fibers and being approximately 0 to 50% by weight of the thermoplastic synthetic fibers. Examples of thermoplastic synthetic fibers include synthetic fibers of polyethylene, polypropylene, polyethylene terephthalate, a blend of synthetic fibers and conjugated fibers including one or more of these types of synthetic resins. The conjugated fibers may be conjugated sheath core-type fibers or eccentric sheath core-type fibers including two synthetic fiber components with different melting points. With this configuration, the short fibers 5 can be crimped so that the back surface layer 3 can be formed to have flexibility and strength.

[0014] The long fibers 4 described here have a fiber length in a range of 30 to 200 mm, and the short fibers 5 described herein have a shorter fiber length than the previous one. The long fibers 4 have an average fiber diameter (a diameter of a single fiber) less than an average fiber diameter of the short fibers 5 of the back surface layer 3. More specifically, the average fiber diameter of the long fibers 4 will preferably be of 0.01 mm or less and more preferably approximately 0.005 mm or less. The average fiber diameter of the short fibers 5 will be approximately 0.01 mm or more, and more preferably from 0.0010 mm to 0.0020 mm. Long fibers 4 have less hydroscopicity than short fibers 5. In this configuration, long fibers 4 may be referred to as low hygroscopic fibers or microfibers, and short fibers 5 may be referred to as high hygroscopicity fibers or absorbent fibers.

[0015] As illustrated in Figs. 3 and 4, the cleaning sheet 1 preferably has a thickness t1 of approximately 0.2 to 0.3 mm. Cleaning sheet 1 preferably has a weight per unit area in the range of approximately 25 to 40 g/m 2 . The cleaning sheet 1 according to the present configuration has a specific volume of approximately 145 m 3 /kg. The front surface layer 2 has a thickness t2 being less than a thickness t3 of the back surface layer 3. Preferably, the thickness t2 of the front surface layer 2 is 20 to 60% of the thickness t3 of the back surface layer 3. Specifically, the thickness t2 of the front surface layer 2 is approximately 0.02 to 0.15 mm, and the thickness t3 of the back surface layer 3 is approximately 0.1 to 0.25 mm. The thickness t2 of the front surface layer 2 being less than 0.2 mm leads to an excessively thin cleaning part of the cleaning sheet 1, resulting in poor cleaning performance. On the other hand, a thickness t2 exceeding 0.15 mm leads to a relatively small thickness t3 of the back surface layer 3, undesirably resulting in low bending stiffness of the cleaning sheet 1. This may lead to the cleaning sheet 1 being weakened or twisted during use.

< Thickness measurement method >

[0016] The thickness t1 of cleaning sheet 1 is measured with a thickness gauge (UF-60 manufactured by DAIEI KAGAKU SEIKI MFG. Co., Ltd.) under a load of 3.0 gf/cm2 being applied to the cleaning sheet. cleaning 1. The thickness t2 and t3 of the front surface layer 2 and the back surface layer 3 are measured by monitoring a cross section of the cleaning sheet with a microscope (Real Surface Viewing Microscope VE-7800 manufactured by KEYENCE CORPORATION ). The density of each of the cleaning sheet 2, the front surface layer 2, and the back surface layer 3 is calculated based on the following formula:

[0017] Density (g/cm3) = weight per unit area (g/m2)/thickness (mm) x 10-3. The specific volume (m3/kg) of cleaning sheet 1 is calculated as the reciprocal of the density (g/cm3) x 103.

[0018] The weight per unit area of the front surface layer 2 is in a range of 5 to 30 g/m2 and is preferably 5 to 15 g/m2. The density of the front surface layer 2 is preferably 0.11 g/cm 3 in the present configuration. When the weight per unit area of the front surface layer 2 is 10 g/m2 or less, the weight per unit area of the back surface layer 2 will be g/m2 or less, the weight per unit area of the layer of back surface 3 being preferably 25 g/m 2 or more. A weight per unit area of the back surface layer 3 will be approximately 10 to 35 g/m 2 and being more preferably 15 to 30 g/m 2 . The density of the back surface layer 3 will preferably be from 0.08 to 0.2 g/cm3 .

[0019] The cleaning sheet 1 according to the present invention is used in both a dry and wet state, and being suitable as a cleaning sheet for removing sebum and cosmetic or similar dirt on the skin, a covering sheet covering material sponge on a cosmetic sponge, and a dampened sheet (moistened paper) impregnated with a cleaning agent. The cleaning sheet used in a wet state may be impregnated with a wetting agent such as water and ethylene glycol, a chemical agent such as alcohol and an antibacterial agent, a flavoring agent or other similar components by a known method. Cleaning sheet 1 may be used as a wipe for interpersonal use as in the present embodiment, or a wipe for objects (including dry) impregnated with a chemical agent such as an antibacterial agent. Furthermore, the cleaning sheet 1 has the front and back surfaces with removal performance for the cleaning system, and could be used as a front sheet of a sanitary napkin, a body side lining of a disposable diaper, or the like. When cleaning sheet 1 is used for such products, the products may have greater permeability and diffusion of body fluid compared to products using other cleaning sheets.

[0020] The front surface layer 2 and the back surface layer 3 of the cleaning sheet 1 may be bonded together by a binder like adhesives, or may be integrally overlapped by various known methods including mechanical entanglement such as needle-punch entanglement and fluid entanglement (air entanglement and hydroentanglement). Among these, hydroentanglement will preferably be used for integration. Cleaning sheet 1 may be formed into a form of a non-woven binder material with layers 2, 3 bonded together with adhesives (binders) while the effect of the present invention is achieved. Further, when the fibers 4 and fibers 5 forming layers 2 and 3 are entangled and integrated together by hydroentanglement, the cleaning sheet can be prevented from being stiff when the binder is used, and the overlapping fiber networks can be prevented. be more rigid and evenly entangled with each other as a whole. In addition, a cleaning sheet that has excellent smoothness and texture can be obtained. When fluid entanglement is not used for forming the cleaning sheet 1, pressing and heating processing can be carried out to obtain the back surface layer 3 having an irregular shape.

< Method for making the cleaning sheet >

[0021] Fig. 5 is a side view schematically illustrating a main part of a manufacturing process for cleaning sheet 1. The main part of the manufacturing process will be described with reference to Fig. 5. First, a composite web 73, obtained by superimposing a first web 71 (upper layer) for forming the front surface layer 2 and a second web (lower layer) 72 for forming the back surface layer 3 one on top of the the other will be directed in an MD machine direction while high pressure water jets will be ejected into it. The composite web 73 is guided to a mesh screen 75 in an endless belt fashion as an apertured support member, after being optionally supplied with a film of water from a tank 74 to form a stable shape. High pressure water jets are ejected from a nozzle 77, on an upper side, having a plurality of holes of a predetermined diameter and harmonized at a predetermined height, while drainage being achieved with a suction 76 operating on a lower side of the screen. mesh 75. A plurality of nozzles 77 are matched in a direction orthogonal to the MD machine direction.

[0022] The mesh fabric 75 is formed flat by weaving with a plurality of threads orthogonal to each other and made of stainless steel, an example of which includes longitudinal threads 75a and side threads 75b orthogonal to each other, and including a plurality of openings and a plurality of hinge parts 78 where wires 75a, 75b intersect each other. In this manufacturing process, high pressure water jets are ejected towards the first mesh so that a flatness of the skin-contacting side of the first mesh 71 is improved, and thus the front surface layer 2 with excellent texture is obtained. Alternatively, high pressure water jets could be ejected towards the second weft 72 and towards the first weft 71 and the second weft 72, while the effect of the present invention described below is achieved. Furthermore, as a pre-entanglement processing, the composite web 73 may be subjected to needle punch processing and then one or both of the surfaces may be subjected to the high pressure water jet. The hinged part 78 is positioned where the longitudinal yarn 75a and the side yarn 75b intersect each other, and thus being swelled towards the composite weft 73.

[0023] Referring again to Figs. 3 to 5, with the above-described high pressure waterjet processing, the fibers of the first weft 71 and the fibers of the second weft 72 are entangled together. Furthermore, in the mesh fabric 75, part of the fibers (short fibers) forming the second mesh 72 and positioned in the hinged part 78 move under the ejection of the high pressure water jets to be re-harmonized in the hinged part 78, and openings 80 not including fibers being formed. In the second mesh 72, a plurality of groove parts 82 harmonized in a transverse direction and extended in the machine direction and ridge parts 81 positioned between the groove parts 82 being formed by the high pressure water jets ejected from the plurality of nozzles 77 harmonized in the transverse direction. The plurality of ridge parts 81 and groove parts 82 are alternately positioned along the second Y direction. The openings 80 are matched in the first X direction (transverse direction) in the groove parts 82 while being spaced apart from each other by a predetermined amount. distance, and thus rows of openings being formed. The first mesh 71 is subjected to high pressure water jet direct ejection processing in a state where the interstitial fibers are relatively small, and the long fibers 4 including nylon microfibers or the like are randomly matched so that the fibers are moveable with each other. Thus, the first mesh 71 has no strength formed and the plurality of openings 80 formed, when the second mesh 72 and the mesh-like structure are formed from randomly curved long fibers 4, and thus a so-called mesh-like structure is obtained. The long fibers 4 are mainly entangled together to be in sheet form, and can also be partially fused together.

[0024] The hydroentanglement is preferably carried out with a relatively low pressure. More specifically, columnar water jets are ejected into the composite mesh 73 at a water pressure of 1 to 8 MPa from the nozzle 77 in which orifices with an orifice diameter of 0.1 to -.5 mm are matched to a range of 0.2 to 2.0 mm. With relatively low pressure water used for processing, the entanglement of the long fibers 4 is not released so that the first mesh 71 can maintain the net-like structure. Furthermore, the second mesh 72 may be formed to have the strength with the ridge parts 81 and the groove parts 82 alternatively matched in the second Y direction.

[0025] The long fibers 4 in the first mesh 71 may be oriented in the MD machine direction depending on how they are manufactured (eg by blow casting). Further, when the long fibers 4 are entangled while being randomly distributed, the net-like structure with randomly curved long fibers 4 can be more easily formed. The long fibers 4 and the short fibers 5 may be entangled with each other in the ridge parts 81 of the back surface layer 3. At least part of the long fibers 4 cross at least part of the numerous openings 80 in the groove parts 82 of the surface layer later 3.

[0026] The cleaning sheet 1 with the superimposed structure can be used, in the dry state and in the wet state, as a sheet for cleaning sebum, cosmetic powder particle such as ceramic, and another, on the skin with the front surface 1a serving as the first cleaning surface. Examples of the sheet include dampened fabrics, cosmetic cleaning sheets, and covering sheets for a cosmetic sponge. Once the front surface 1a formed in the front surface layer 2 has the net-like structure formed of long micro fibers 4, when the surface is pressed against the face in a frictional manner, cosmetic powder, tallow and others can be scraped off and collected. within spaces in the net-like structure with the long fibers 4, serving as edges of the net-like structure which are peripheral edges thereof, exerting an edge effect to enter the skin pores. Consequently, the front surface layer 2 has a brushing function.

[0027] To achieve the brushing function, for example, microfibers obtained by split split type conjugated fibers can be used as the fibers forming the front surface layer 2. However, the skin may be irritated when rubbed by the front surface formed of microfibers. obtained by division. The cleaning sheet 1 according to the present invention with the front surface layer 2 formed of long fibers 4 including undivided microfibers including nylon or the like should not cause skin irritation. The front surface 1a does not include extreme fibers while the long fibers 4 which are not cut in the manufacturing process for the cleaning sheet 1, and the cause of skin irritation with extreme fibers coming in contact with the skin can be reduced. The back surface layer 3 forming the back surface 1b includes the plurality of ridge parts 81 and groove parts 82 extending in the first X direction and alternatively matching in the second Y direction. In addition, the plurality of openings 80 are formed in the backing parts. grooves 82. Thus, the rear surface 1b could still function as a second cleaning surface. More specifically, the back surface 1b with a flat shape without gaps or irregularities fails to capture dirt such as cosmetic dust and dust, and is unable to sufficiently clean the dirt on the surface of your skin. Since the cleaning sheet 1 according to the present configuration has the plurality of openings 80 formed in the back surface layer 3, the back surface 1b is not flat, and can capture the stain as cosmetic powder and dust with the openings 80 when being rubbed on the skin, and thus can have sufficient cleaning performance. Thus, the user of the cleaning sheet 1 can freely choose and use either of the front surface 1a and the rear surface of the cleaning sheet 1 functioning like the cleaning sheet described above with the side of the back surface 1b not being flat, the layer back surface 3 may not necessarily have the robustness with the plurality of ridge parts 81 and groove parts 82. <Using the cleaning sheet in the dry state>

[0028] Fig. 6 is a perspective view of a cosmetic sponge 10 including: a cushion (pad) layer 20 formed from absorbent fibers and a cover sheet 21 formed from the cleaning sheet 1 as a base material and wrapping the cushion layer 20. Fig. 7 is a cross-sectional view taken along line VII-VII through Fig. 6. The cover sheet 21 has a skin-contacting surface and a non-skin-contacting surface, as well as an outer layer 24 positioned on the side of the skin-contacting surface corresponding to the front surface layer 2 of the cleaning sheet 1 and an inner layer 23 corresponding to the back surface layer 3.

[0029] The skin-contacting surface of the cosmetic sponge 10 has long fibers 4 with low hydroscopicity randomly curved, forming a net-like structure on the outer layer 24. Thus, a substantially uniform liquid film is formed with the liquid as a cosmetic liquid. impregnated from the skin-contacting surface evenly spreading on the skin-contacting surface of the cosmetic sponge 10. Thus, when the dirt on the skin is cleaned with the cosmetic sponge 10 impregnated with a liquid cleaning agent, the dirt on the entire skin may be cleaned with the liquid cleaning agent evenly infiltrating the skin. When the cosmetic sponge 10 impregnated with a relatively large amount of liquid cosmetic is used as a packaging sheet for the cosmetic, excellent skin adhesion can be achieved with the cosmetic liquid uniformly infiltrating over the entire surface in contact with the skin.

[0030] With the long microfibers 4 harmonized into a net-like structure in the front surface layer 2, a plurality of relatively small inter-fiber slits are formed. Thus, a better brushing function is obtained compared to a configuration in which the fibers are harmonized so densely that no interstitial fibers are formed. Furthermore, greater liquid retention performance as a cosmetic liquid in the front surface layer 2, compared to a configuration with relatively large interstitial fibers, or the configuration with the plurality of apertures 80 as in the back surface layer 3. More specifically, the long fibers 4 are formed from hygroscopic fibers with relatively low hydroscopicity. This enables the liquid to enter the interstitial fibers without being absorbed by the fibers to stably maintain surface tension in the front surface layer 2 for a predetermined period of time. Thus, when the cover sheet 21 is impregnated with a relatively small amount of cosmetic liquid, the cosmetic liquid will not immediately be absorbed by the inner layer 23 or the cushion layer 20, and thus, the outer layer 24 is maintained in the moistened state for a predetermined amount of time. period of time. Thus, the skin-contacting surface of the front surface layer 2 impregnated with the cosmetic liquid will not return to the dry state with the cosmetic liquid seeping in before the sponge contacts the face. The randomly curved long fibers 4 form a mesh-like structure in the front surface layer 2, and through the openings 80 of the back surface layer 3. This means that the mesh-like structure is also formed over the openings 80. Thus, the cosmetic liquid impregnated in the front surface layer 2 does not move directly to the cushion layer 20 of the opening 80, and excellent liquid retention performance will be achieved as described above.

[0031] Cleaning sheet 1 only including micro long fibers 4 has excellent cleaning performance, but involves a risk of having low sheet strength due to low stiffness. With the front surface layer 2 integrated with the back surface layer 3 formed of short fibers 5 having an average fiber diameter greater than that of long fibers 4, the cleaning sheet 1 has an appropriate level of stiffness, and appropriate sheet strength being achieved. Thus, the cleaning sheet 1 in the dry state and in the wet state involves a lower risk of greatly deforming or having the front surface layer 2 twisted, and thus a stable cleaning operation can be carried out. The back surface layer 3 has sturdiness formed with the plurality of ridge parts 81 and groove parts 82. Thus, greater sheet strength and flexural rigidity of the wiping sheet will be achieved compared to a configuration with a flat back surface layer. , and the impregnated liquid will be able to move quickly.

[0032] As described above, when the cleaning sheet is used for the covering sheet 21 of the cosmetic sponge 10, the long fibers 4 form the net-like structure on the surface in contact with the skin, and thus dirt or the like that have entry into the skin pores can be eliminated. In addition, the surface in contact with the skin is impregnated with the cosmetic liquid, and evenly the liquid film is formed, so that the skin can be evenly cleaned. The inner layer 23 has the strength by the plurality of ridge parts 81 and groove parts 82, whereby proper rigidity is achieved so that stable cleaning operation can be carried out. Furthermore, cosmetic liquid or the like moved to the inner layer 23 may spread over the entire sheet along the grooved parts 82, and may be rapidly absorbed into the cushion layer 20 through the plurality of openings 80.

< Use in the moistened state >

[0033] Fig. 8(a) is a perspective view of a container 91 refilled with wet sheets (wet wipes) 90 each including cleaning sheet 1 as a base material. Fig. 8(b) is a schematic partial side view of a stack, including a plurality of wet sheets 90 in a stacked state, contained in a container 91.

[0034] As illustrated in Fig. 8(a), container 91 has a drag opening 93 that can be opened and closed, and containing the stack of wet sheets 90 superimposed on top of each other while being folded into a Z-shape and an inverse Z-shape. A wet sheet 90a on top of the stack of wet sheets 90 is partially pulled out of the opening 93. When the catch part is pulled, the wet sheet 90a is separated from the wet sheet 90b on which the wet sheet 90a is stacked to be pulled from the container. 91. Then, part of the wetted sheet 92b will be pulled from the opening 93.

[0035] The wet sheets 90 contained in the above-described manner have excellent cleaning performance due to the net-like structure achieved with the long fibers 4 in the front surface layer 2, and appropriate rigidity and shape-retaining property by the back surface layer 3 , as in a cosmetic sponge 10, and a stable cleaning operation can be performed. The wetted sheet 90 has the back surface layer 3 primarily including the absorbent short fibers such as rayon, and may be contained in the container 91 while being in a state of retaining a certain amount of the wetted components such as water or alcohol in advance. Furthermore, with the plurality of openings 80, excellent permeability can be achieved in a thickness direction. Thus, air will be less likely to be trapped between the moistened sheets 90 in a moistened state superimposed on top of each other.

[0036] As illustrated in Fig. 8(b), in the stack of wet sheets 90 folded into Z-shape and inverted Z-shape and superimposed on top of each other, the back surface layer 3 of the wet sheet 90a to be pulled first and the back surface layer 3 of the wetted sheet 90b to be pulled next to each other while being in contact with each other. When the back surface layer 3 (back surface 1b) is flat, slippage may occur in a part where the back surface layer 3 is in contact with each other, more specifically, between the back surface layer 3 of the wet sheet 90a being pulled and the back surface layer 3 of the wetted sheet 90b being pulled close when the wetted sheet 90 is pulled. As a result, the wetted sheet 90b may fail to have a sufficiently pulled portion of the opening 93 to be easily retained. In the wet sheet 90 formed from the cleaning sheet 1 according to the present configuration, the back surface 1b is not flat due to the plurality of openings 80 formed in the back surface layer 3. Thus, the wet sheet 90b to be pulled close is retained. by the wetted sheet 90a being pulled, whereby part of the wetted sheet 90b of the opening 93 is securely pulled.

[0037] The front surface layer 2 and/or the back surface layer 3 on the cleaning sheet according to the present invention may not be a single layer and may be multiple layers. In particular, the multilayer structure may be used for a sheet intended to be used in the wetted state, to achieve greater sheet strength. Examples of said configuration include a configuration with each of the front surface layer 2 and the back surface layer 3 having a double layer structure, a fibrous mesh configuration used as the back surface layer 3 interposed between the fibrous meshes used as the front surface layer 2 in the illustrated example; and a configuration with the back surface layer 3 or the front surface layer 2 of a single layer superimposed between the front surface layers 2 and the back surface layers 3 of the double layer structure.

[0038] In the present invention, the content of long fibers 4 including microfibers in the front surface layer 2 is approximately 60 to 100% by weight. Thus, cleaning sheet 1 has more contact points, and superior texture and adhesion against a target object, compared to a configuration with the content being approximately 60% or less. The long fibers 4 are dispersed as monofibers. Alternatively, a plurality of monofibers may be aggregated to form a fiber bundle (tow). When the long fibers are bundled together, large dirt can be captured with the bundle, and small dirt can be removed and collected in the bundle by the ultrafine long fibers 4 forming the bundle, entering the skin pores. Consequently, higher cleaning performance will be achieved.

[0039] The configuration of the cosmetic sponge 10 using the cleaning sheet 1 will be further described with reference to Figs. 6 and 7. The cosmetic sponge 10 is defined by a first direction and a second direction R intersecting with each other, and includes a first surface 11, and a second surface positioned on opposite sides, both side edges 13, 14 extending in the first direction. S, both end edges 15, 16 extending in the second direction R, a first end part 17 and a second end part 18 separated from each other in the first direction S, and an intermediate part 19 positioned between the first and second end parts 17 and 18. The intermediate part 19 has a uniform width in the second direction R. In each of the first and second end parts 17 and 18, one corresponding to one of both side edges 13 and 14 is angled so that the length in the second direction R gradually decreases by towards one of the corresponding end edges 15 and 16. The cover sheet 21 is in an overlay form to be wrapped around the cushion layer 20, and having overlapping portions attached. together at both connecting parts 45, 46 along both side edges, and thus the overlapping state being retained. With the overlapping state of the cover sheet 21 thus retained, an open/closed pocket 50 including an opening edge part 51 extending in the second direction R is formed between both bonded parts 45 and 46. The cosmetic sponge 10 has a length L1 at first direction S which is approximately 45 to 65 mm, and having a length L2 in the second direction R which is approximately 65 to 85 mm. The intermediate part 19 has a longer length than that of the first and second end parts 17 and 18 in the first S direction.

[0040] Cushion layer 20 on cosmetic sponge 10 preferably has a basis weight of approximately 0.2 to 0.4 g. Cushion layer 20 preferably has a greater weight per unit area at the intermediate portion 19 than at the first and second end portions 17 and 18. The cushion layer 20 may have substantially the same weight per unit area or may have different weights per unit area. unit on the first and second end pieces 17 and 18. In the present embodiment, the weights per unit area on the first and second end pieces 17 and 18 are substantially the same. For example, when the cushion layer 20 has a greater weight per unit area in the first end part 17 than in the second end part 18, greater softness can be achieved in an end part (the first end part 17) on a side inserted a finger. . Thus, the user of the cosmetic sponge 10 feels the smooth texture when inserting the fingers into the pocket 50 through the edge part of the opening 51.

[0041] Cushion layer 20 is a fiber assembly primarily including hydrophilic fibers. The hydrophilic fibers may be blended into the fiber assembly, while the predetermined hydroscopicity of the cushion layer 20 will not be worsened. More specifically, the hydrophilic fiber content will be 80% by weight or more. Examples of hydrophilic fibers include rayon fibers, cotton fibers, and acrylic fibers. For example, the hydrophobic fibers may be synthetic fibers formed from synthetic resins such as polyethylene, polyester, and polypropylene, and the like; conjugated fibers including synthetic fibers formed from these synthetic resins. Cushion layer 20 according to the present configuration is formed from a fiber assembly primarily including rayon fibers. When rayon fibers are used as hydrophilic fibers, water separation will be easier when a sponge impregnated with cosmetic water is used, compared to when cotton fibers are used.

[0042] For example, when the outer layer 24 is formed of long fibers 4 having relatively long fiber length greater than the length of the cosmetic sponge 10 in the first S direction and/or the second R direction, the first and second surfaces 11 and 12 not including any extreme fiber parts. When the outer layer 24 is formed of short fibers 5 with the end parts of the fibers disposed on the first and second surfaces 11 and 12, the end parts may contact and irritate the skin when the cosmetic sponge 10 is used. Thus, with the long fibers 4 continuously formed on the first and second surfaces 11 and 12 to have end parts disposed only on a part of the outer edge of the cosmetic sponge 10, superior texture can be achieved compared to when short fibers are used. The cosmetic sponge 10 according to the present configuration has a connecting part 44 formed on the inner side of each of both side edges 13 and 14 of the cosmetic sponge 10 as lines cut from the cover sheet 21. Thus, the region of application of a cosmetic liquid, defined by the connecting parts 44 and both end edges 15 and 16, on the second surface 12 not including long fiber end parts 4, and thus excellent texture being achieved.

[0043] The inner layer 23 including hydrophobic thermoplastic fibers has low hygroscopicity/hydropicity leading to less effect of the design of the cosmetic liquid or the like held in the outer layer 24, and achieving uniformly greater retention of liquid on the surface in contact with the skin. The overlapping parts of the cover sheet 21 on each of the connecting parts 45 and 46 may be bonded together by stamping or not with heat or ultrasonic waves, preferably by melting. In said instance, the inner layer 23, as one of the inner layer and the outer layer 24 facing each other, including rayon fibers with no melting property can result in low bond strength.

[0044] In view of this, the inner layer 23 may include thermosetting fibers so that the inner layer 23 and the outer layer 24 are easily fused together. Thus, high bond strength is achieved in the bonding parts 44, and thus the parts are prevented from being separated from each other during use.

[Examples]

[0045] Specific Examples and others of the present invention will be described below. It should be noted, however, that the present invention is not limited to the Examples described below: [Example 1] - Cleaning sheet: thickness 0.25 mm, weight per unit area 30 g/m2, - Front surface layer: thickness 0.09 mm, weight per unit area 10 g/m2, - Blow-spun non-woven material (nylon 6: 100% by weight), - average fiber diameter of long fibers 0.004 mm , - Back surface layer: thickness 0.16 mm, weight per unit area 20 g/m2, - Hydro-entangled non-woven material (short fibers: rayon 80% by weight, thermally bonded fibers 20% by weight), - Average fiber diameter of the fibers short (0.0016 mm rayon and thermal binding fibers). [Example 2] - Cleaning sheet: thickness 0.25 mm, weight per unit area 30 g/m2, - Front surface layer: thickness 0.09 mm, weight per unit area 10 g/m2, - Material not blow-spun fabric (nylon 6: 100% by weight), - Average fiber diameter of long fibers 0.004 mm, - Back surface layer: thickness 0.16 mm, weight per unit area 20 g/m2, - Fibers rayon (rayon: 100% by weight), - Average diameter of short fiber fiber (rayon) 10.005 mm . [Comparative Example 1] - Cleaning sheet (single sheet): thickness 0.27 mm, weight per unit area 30 g/m2, - Blow-spun non-woven material (nylon 6: 100% by weight), - Diameter fiber average of long fibers 0.004 mm . [Comparative Example 2] - Cleaning sheet (single sheet): thickness 0.25 mm, weight per unit area 30 g/m2, - Hydro-entanglement non-woven material (cotton: 100% by weight), - Average diameter of fiber 10.005 mm. [Comparative Example 3] - Cleaning sheet (single sheet): thickness 0.25 mm, weight per unit area 30 g/m2, - Hydro-entanglement non-woven material (rayon: 100% by weight), - Average diameter of fiber 10.005 mm.

[0046] For each of the Examples and Comparative Examples, an average surface frictional coefficient (MIL), an average deviation of the surface frictional coefficient (MM D), and an average deviation of surface stiffness (SMD) were measured as characteristics of the surface, and a cleaning test and a sensory test were performed. Table 1 illustrates measurement results and test results. These measurements are performed with KES manufactured by KATO TECH CO., LTD. to obtain well-known characteristic values indicating texture of a non-woven material (reference document: Standardization and analysis of handling (second edition) written by S. Kawabatam and published July 10, 1980).

[0047] Assessment standards for each of the measurements and the tests for each of the measurement items illustrated in Table 1 will be described below. Test results were rated A (excellent), B (good), C (normal) and D (poor). < Measurement for surface features >

[0048] Surface characteristics were measured by using KES-FB4 manufactured by KATO TECH CO., LTD, for one species, such as 1.0 cm x 1.0 cm area in a cosmetic application region for each sample , placed on a metal test board. Roughness was measured using a probe with a load of 10gf applied to a surface of the species. The probe was obtained by taking a winding piano wire having a diameter of 0.5 mm on a coin with a width of 0.5 cm. Surface friction was measured with a contact surface of a probe, obtained by harmonizing piano wires each having a diameter of 0.5 mm, in contact with pressure with the species due to the force of 50 gf applied to the probe with a weight. Surface friction and surface roughness were measured with the species moved horizontally by 2 cm at a speed of 0.1 cm/sec. and with uniaxial tension of 20 gf/cm applied to the species. The characteristic values were measured in the first X direction and in the second Y direction for the species, and an average of them was obtained. < Standard rating > 1. Average surface friction coefficient (MIU) value - A: 0.25 or more - B: 0.20 or more, less than 0.25 - C: 0.15 or more, less than 0 .20 - D: none of the above 2. Mean deviation of the surface frictional coefficient (MM D) - A: 0.0080 or less - B: more than 0.0080; 0.0090 or less - C: more than 0.0090; 0.0100 or less - D: more than 0.0100 3. Value of mean surface roughness deviation (SMD) [mm] - A: 4.0 or less - B: more than 4.0; 4.5 or less - C: more than 4.5; 5.0 or less - D: more than 5.0 - Cleaning test >

[0049] The cleaning test for a cosmetic (cream base) was carried out by using cleaning sheet 1 according to the present invention and cleaning sheets according to Comparative Examples.

[0050] A friction and wear tester TL201Ts manufactured by Trinity-Lab Inc. was used as a test device. Cleaning sheets according to Comparative Examples and cleaning sheets 1 as species were tested without any liquid as a cosmetic liquid applied to them. First, a test piece was prepared by applying 0.02 g of cosmetic to a surface of a rectangular sliding glass piece having a width of 26 mm and a length of 90 mm to be in the shape of a circle with a diameter of 13 mm and a center in a position separated from the longitudinal extreme edge by 20 mm.

[0051] Thus, the cleaning sheet 1 as the species was fixed by a dedicated sponge template (length: 20 mm, width: 70 mm) of the test device with the front surface 1a exposed. After that, the cosmetic on the test piece for 40 minutes was cleaned, with the species moved at a movement speed of 2.5 mm/s for 60 mm from an extreme edge of the test piece, with a predetermined load applied. on the dedicated template (a load of 100 g applied to an area of 5.2 cm2 on cleaning sheet 1 in contact with the test piece). Generally widely viable cream base (including components such as an aseptic, surfactant, ultra-violet absorbent, tar-based pigment, and artificial flavoring, for example) was used as the cosmetic in the measurements.

[0052] The surface of the test piece after the cosmetic was cleaned was scanned by a scanner (digitizer) (GT-X750 manufactured by Seiko Epson Corp). Thus, a resulting image was read with imaging software (Adobe Photoshop Elements 3.0). and then binarization processing was performed with histogram processing performed using Histogram Analysis Software. A cleaning rate was obtained as a percentage value obtained by binarizing processing on the test piece after cleaning, relative to a value obtained by binarizing processing on the test piece before cleaning (100%). The number of species in each Example was N = 3, and an average value was calculated with the species. - Rating > - A: clean rate: 90% or more - B: clean rate: 80% or more, less than 90% - C: clean rate: 70% or more, less than 80% - D: clean rate: less than 70% - Sensory evaluation >

[0053] Wet sheets prepared with distilled water infiltrated into each cleaning sheet having a size of 12 cm x 12 cm, to have a weight of three times as large as the sheet. Thus, 10 female interviews wiped the base cream on their face with the moistened sheets, and rated the “feel of softness”, “smoothness”, and “feel of cleanliness” of the moistened sheets based on four levels. 1. Feeling of softness - A: A lot - B: A little - C: Couldn't say - D: Not at all 2. Softness - A: A lot - B: A little - C: Couldn't say - D: Not at all 3. Clean feeling - A: A lot - B: A little - C: Could not say - D: Not at all - Measurement Result >

[0054] As illustrated in Table 1, the average surface friction coefficient (MIU) was 0.25 or more, the average deviation of the surface roughness coefficient (MM D) was 0.008 or less, and the average deviation of surface roughness (SMD) was 4.0 or less [unit: mm] on the front surface side 1a of cleaning sheet 1 according to each of Examples 1 and 2, the MIU was 0.25 or less, the MM D being 0.008 or less, and the SMD being 5.0 or less on the cleaning sheet according to Comparative Example 1. The MIU was less than 0.20, the MM D was 0.008 or less, and the SMD was 4.0 or less on the cleaning sheet according to Comparative Example 2. The MIU was less than °20, the MM D was greater than 0.100, and the SMD was 5.0 or less on the cleaning sheet according to Comparative Example 3. The cleaning test results indicated that the cleaning rate of each of the cleaning sheets 1 according to Examples 1 and 2 and the cleaning sheet according to Comparative Example 1 was 90%or more, and thus a high clean rate exceeding 90% was achieved in a state with no cosmetic liquid applied. The clean rate of the cleaning sheets according to Comparative Examples 2 and 3 was less than 80%.

[0055] The results of the evaluations of the measurements described above indicated the following fact: Specifically, the cleaning sheet 1 according to each of Examples 1 and 2 has the long fibers randomly curved forming a net-like structure on the side of the front surface 1a and being relatively flat on the front surface 1a. Thus, liquid such as cosmetic liquid supplied on the front surface 1a uniformly spreads integrally over the front surface 1a, and may form a uniform liquid film. The cleaning sheet 1 according to each of Examples 1 and 2 has the long fibers 4 including microfibers so that a plurality of edge parts are formed on the front surface 1a and having relatively high frictional strength. Thus excellent handling can be achieved, and minimal dirt in the skin pores can be eliminated and cleaned.

[0056] As described above, the cleaning sheet 1 according to each of Examples 1 and 2 has the front surface 1a formed of long fibers 4 including microfibers, and thus being relatively flat and having relatively high frictional strength. These sheet characteristics were confirmed by current use with “Feeling soft”, “Smoothness”, and “Feeling clean” of cleaning sheet 1 rated “A” in the sensory test. The cleaning sheet according to each of Comparative Examples 1 to 3 has an irregular front surface and a relatively low frictional resistance. Thus, the formation of a uniform liquid film and a sufficient brushing function as in Examples 1 and 2 were not obtained and none of the sensory evaluation items were rated "A".

[0057] A cleaning sheet material 1 according to the present invention includes materials described in this specification, and may further include various known materials commonly used for these types of items without limitation. The terms “first”, “second” and “third” in the report and claims are used merely to distinguish similar elements, positions and others.

[0058] The present invention described above may at least be harmonized in the following: - A cleaning sheet having a first direction and a second direction intersecting with each other, the cleaning sheet including a front surface layer mainly including hygroscopic long fibers having an average fiber diameter of 0.01 mm or less and a back surface layer mainly including short fibers with an average fiber diameter of more than 0.0010 mm. The randomly curved long fibers form a net-like structure on the front surface layer. A plurality of openings matched in the first direction are formed in the back surface layer. Long fibers cross at least some of the openings.

[0059] The present invention according to the paragraph described above, may include at least the following configurations: (1) The back surface layer further including a plurality of groove parts and a plurality of ridge parts extending in the first direction. The groove parts and the ridge parts are alternatively harmonized in the second direction. The plurality of openings are formed in the slotted parts. (2) The front surface layer has a density of 0.05 to 0.2 g/cm3. The front surface layer has a thickness being approximately 20 to 60% of a back surface layer thickness. (3) The front surface layer in a dry state has a clean rate of at least 80%. (4) The front surface has a mean surface friction coefficient (MIU) of 0.25 or more and a mean surface roughness deviation (SMD) of 0.004mm or less. (5) Long fibers include nylon. (6) Short fibers are fibers with greater hygroscopicity than that of long fibers. (7) Short fibers are at least one type of cellulosic fiber including rayon and cotton. (8) The front surface layer and the back surface layer are hydro-entangled non-woven materials integrated by hydro-entanglement. [List of Reference Signs] 1 cleaning sheet 2 front surface layer 3 back surface layer 4 long fibers 5 short fibers 80 opening 81 crest part 82 groove part t2 front surface layer thickness t3 surface layer thickness posterior X first direction Y second direction

Claims (9)

1. "CLEANING SHEET", having a first direction and a second direction intersecting with each other, characterized in that it comprises a front surface layer primarily including hygroscopic long fibers having an average fiber diameter of 0.01 mm or less, and a layer back surface mainly including short fibers with an average fiber diameter of more than 0.0010 mm, where the randomly curved long fibers form a net-like structure in the front surface layer, and by a plurality of openings harmonized in the first direction are formed in the back surface layer, and in that the long fibers cross at least some of the openings. 2. "CLEANING SHEET" according to claim 1, characterized in that the back surface layer further includes a plurality of groove parts and a plurality of ridge parts extending in the first direction, and in that the groove parts and the ridge parts are alternatively matched in the second direction, and in that the plurality of openings are formed in the groove parts. 3. "CLEANING SHEET", according to any one of the preceding claims, characterized in that the front surface layer has a density of 0.05 to 2.0 g/cm3, and in that the front surface layer has a thickness being from approximately 20 to 60% of a back surface layer thickness. 4. "CLEANING SHEET", according to any one of the preceding claims, characterized in that the front surface layer in a dry state has a cleaning rate of at least 80%. 5. "CLEANING SHEET", according to any one of the preceding claims, characterized in that the front surface has an average surface friction coefficient (MIU) of 0.25 or more and a surface roughness deviation (SMD) of 4 .0 or less. 6. "CLEANING SHEET", according to any one of the preceding claims, characterized in that the long fibers include nylon. 7. "CLEANING SHEET", according to any one of the preceding claims, characterized in that the short fibers are fibers with greater hygroscopicity than that of the long fibers. 8. "CLEANING SHEET", according to any one of the preceding claims, characterized in that the short fibers are at least one type of cellulosic fiber including rayon and cotton. 9. "CLEANING SHEET", according to any one of the preceding claims, characterized in that the front surface layer and the rear surface layer are of hydro-entangled non-woven materials integrated by hydro-entanglement.

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