CN107105869B

CN107105869B - Wiping sheet

Info

Publication number: CN107105869B
Application number: CN201680005661.0A
Authority: CN
Inventors: 池田祐子; 田中嘉则; 坂东健司
Original assignee: Unicharm Corp
Current assignee: Unicharm Corp
Priority date: 2015-02-17
Filing date: 2016-01-18
Publication date: 2021-08-10
Anticipated expiration: 2036-01-18
Also published as: CN107105869A; KR102449531B1; TW201702447A; KR20170117022A; PH12017501163B1; MY180038A; BR112017014613A2; JP2016151070A; TWI683046B; PH12017501163A1; WO2016132790A1; JP6429664B2; BR112017014613B1

Abstract

The invention provides a wiping sheet which has good skin touch on the front surface side and can exert wiping performance on the front surface side and the back surface side. In a wiping sheet (1) having a surface layer (2) composed mainly of hygroscopic long fibers (4) having an average fiber diameter of 10 [ mu ] m or less and a back surface layer (3) composed mainly of short fibers (5) having an average fiber diameter exceeding 10 [ mu ] m, the long fibers (4) are irregularly drawn in an arc shape in the surface layer (2) and uniformly spread in a mesh shape, a plurality of openings (80) are formed in the back surface layer (3) so as to be aligned in a first direction (X), and the long fibers (4) span at least a part of the openings (80).

Description

Wiping sheet

Technical Field

The present invention relates to a wiping sheet, and more particularly, to a wiping sheet capable of wiping in a dry state and a wet state.

Background

Conventionally, a wiping sheet using an ultrafine fiber (microfine fiber) having an average fiber diameter of 10 μm or less is known. For example, patent document 1 discloses a wiping sheet having a surface layer containing ultrafine fibers formed by splitting (opening) split composite fibers and a back layer containing hydrophilic fibers having a larger average fiber diameter than the ultrafine fibers.

Documents of the prior art

Patent document

Patent document 1: japanese patent No. 3944526

Disclosure of Invention

Problems to be solved by the invention

When the wiping sheet is used in a dry or wet state as a sheet for wiping sebum or cosmetic dirt on the face, the surface layer made of the ultrafine fibers is brought into direct contact with the skin of the user, and the ultrafine fibers penetrate into pores to remove sebum or cosmetic dirt, so that the wiping sheet is excellent in wiping properties, and is low in irritation to the skin and excellent in skin texture.

However, when a cross section in the radial direction of the split type composite fiber of the surface layer is observed, the surface of the fiber cannot draw a smooth curve, and therefore, when the fiber comes into contact with sensitive skin, skin irritation may be given. In addition, since the back surface formed of the back surface layer including the hydrophilic fiber is smooth, it is difficult to function as a wiping surface. Therefore, when the user selects the back surface of the wiping sheet as the wiping surface, cosmetic powder or dust adhering to the face cannot be sufficiently captured.

The purpose of the present invention is to provide a wiping sheet having a good skin feel on the surface and exhibiting wiping properties on both the front and back surfaces.

Means for solving the problems

In order to achieve the above object, the present invention relates to a wiping sheet having: a surface layer mainly composed of long hygroscopic fibers having an average fiber diameter of 10 μm or less, and a back layer mainly composed of short fibers having an average fiber diameter of more than 10 μm.

According to the wiping sheet of the present invention, the long fibers extend in a mesh shape and are irregularly curved in the surface layer, and a plurality of openings are formed in the back layer in parallel in the first direction, and the long fibers span at least a part of the openings.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the wiping sheet of one or more embodiments of the present invention, the surface layer is formed into an arc shape as long fibers having an average fiber diameter of 10 μm or less, and the long fibers are uniformly spread in a mesh shape, so that the wiping sheet has a good feeling on the skin and an excellent brushing effect, and when a liquid such as a cosmetic liquid is supplied, a uniform liquid film is formed, and the skin can be uniformly moistened. Further, the back layer can trap cosmetic powder or fine dust when the back layer is wiped against the skin by forming a plurality of openings in parallel in the first direction.

Drawings

The drawings show specific embodiments of the wiping sheet according to the present invention, including not only the indispensable structure of the invention but also selected and preferred embodiments.

FIG. 1 is a perspective view of a wiping sheet according to the present invention.

Fig. 2 is a partially enlarged plan view of the surface layer.

Fig. 3 is a sectional view taken along the line III-III of fig. 1.

Fig. 4 is a partially enlarged view of an area surrounded by a chain line IV in fig. 3.

Fig. 5 is a side view schematically showing a main part in a manufacturing process of the wiper blade.

Fig. 6 is a perspective view of a cosmetic pad using a wiping sheet according to the present invention.

Fig. 7 is a sectional view taken along line VII-VII of fig. 6.

Fig. 8(a) is a perspective view of a container for reloading a wet sheet, and (b) is a partially enlarged side view of a wet sheet stacked body in the container.

Detailed Description

The embodiments described below relate to the wiping sheet 1 shown in fig. 1 to 8 as an example of the present invention, and include not only an indispensable configuration of the invention but also an optional and preferable configuration.

Referring to fig. 1 and 2, a wiping sheet 1 according to the present invention has a first direction X and a second direction Y intersecting the first direction X, and includes a front surface 1a and a back surface 1b, and a surface layer 2 and a back surface layer 3 laminated to each other. The surface layer 2 is formed of a nonwoven fabric mainly composed of meltblown fibers of hygroscopic long fibers 4 having an average fiber diameter of 10 μm or less. As the long fibers 4, for example, polyamide fibers such as nylon 6 and nylon 66, acrylic fibers, or hydrophilized hydrophobic fibers can be used. The content of the long fibers 4 in the surface layer 2 is about 60 mass% or more, preferably about 95 mass% or more, and in the present embodiment 100 mass%.

The back surface layer 3 includes short fibers 5 such as cellulose-based short fibers or thermoplastic synthetic short fibers, such as regenerated fibers having moisture absorption, such as staple fibers, pulp fibers, and natural fibers having moisture absorption. The content of short fibers in the back layer 3 is about 50 to 100% by mass of cellulosic short fibers and about 0 to 50% by mass of thermoplastic synthetic fibers. As the thermoplastic synthetic fibers, for example, synthetic fibers such as polyethylene, polypropylene, and polyethylene terephthalate, a mixture of synthetic fibers, or composite fibers using two or more of these synthetic resins can be used. Further, as the composite fiber, a core-sheath type or an eccentric type including two synthetic fiber components having different melting points may be used, and the back surface layer 3 having stretchability or bulkiness may be formed by crimping the short fibers 5 using the core-sheath type or the eccentric type.

The long fibers 4 have a fiber length in the range of 30 to 200mm, and the short fibers 5 have a fiber length smaller than that of the long fibers. The average fiber diameter (diameter of single fiber) of the long fibers 4 is smaller than the average fiber diameter of the short fibers 5 of the back surface layer 3, specifically, the average fiber diameter of the long fibers 4 is preferably 10 μm or less, more preferably about 5 μm or less, and the average fiber diameter of the short fibers 5 is about 10 μm or more, more preferably 10 to 20 μm. The long fibers 4 are less hygroscopic than the short fibers 5, and in the present specification, the long fibers 4 are referred to as very fine fibers and/or low hygroscopic fibers, and the short fibers 5 are referred to as highly hygroscopic fibers or water-absorbent fibers.

Referring to FIGS. 3 and 4, the thickness t1 of the wiping sheet 1 is preferably about 0.2 to 0.3mm, and the mass per unit area of the wiping sheet 1 is preferably about 25 to 40g/m²Within the range of (1). In addition, the specific volume of the wiping sheet 1 is about 145m in the present embodiment³In terms of/kg. The thickness t2 of the surface layer 2 is smaller than the thickness t3 of the back layer 3, and the thickness t2 of the surface layer 2 is preferably 20 to 60% of the thickness t3 of the back layer 3. Specifically, the thickness t2 of the front layer 2 is about 0.02 to 0.15mm, and the thickness t3 of the back layer 3 is about 0.1 to 0.25 mm. If the thickness t2 of the surface layer 2 is less than 0.02mm, the wiping portion of the wiping sheet 1 may become too thin and the wiping performance may be reduced, while if the thickness t2 exceeds 0.15mm, the thickness t3 of the back layer 3 becomes relatively small, so that the bending rigidity of the wiping sheet 1 may be reduced, the body bone of the wiping sheet 1 may be weakened and curling may occur during use.

< method for measuring thickness >

With respect to the thickness dimension t1 of the wiping sheet 1, 3.0gf/cm was applied to the wiping sheet 1²Under the load condition of (1), the measurement was carried out by a thickness meter (manufactured by Daorhiki Seisakusho K.K., UF-60). The thickness dimensions t2 and t3 of the surface layer 2 and the surface layer 3 were measured by observing the cross section of the wiper blade 1 with a microscope (model No. キ - ンス, リアルサ - フェィスビュ - (real time surface observation microscope) microscope VE-7800). The densities of the wiping sheet 1, the surface layer 2 and the back surface layer 3 were determined based on the density (g/cm)³) Mass per unit area (g/m)²) Thickness dimension (mm). times.10^－3To calculate the specific volume (m) for the wiping sheet 1³/kg) as density (g/cm)³)×10³The reciprocal of (a).

The mass per unit area of the surface layer 2 is 5 to 30g/m²More preferably 5 to 15g/m². The density of the surface layer 2 is preferably about 0.05 to 0.2g/cm³In the present embodiment, about 0.11g/cm³When the mass per unit area of the surface layer 2 is about 10g/m²In the following case, the mass per unit area of the back surface layer 3 is preferably about 25g/m²The above. The back surface layer 3 has a mass per unit area of about 10 to 35g/m²More preferably about 15 to 30g/m². The density of the back layer is preferably about 0.08-0.2 g/cm³。

The wiping sheet 1 of the present invention can be used in both a dry state and a wet state, and is suitable for use as a wiping sheet for wiping off sebum or dirt such as makeup adhering to the skin, a sheet for covering cotton wool of a cosmetic pad, and a wet sheet (wet tissue) impregnated with a cleaning agent. When the wiping sheet 1 is used in a wet state, water, a wetting agent such as ethylene glycol, an agent such as alcohol or an antibacterial agent, a perfume, and other components may be impregnated by a known method. As in the present embodiment, the wiping sheet 1 can be used as a face sheet of a sanitary napkin, a body-side liner of a disposable diaper, or the like, by utilizing the washability of the surface and back surfaces, in addition to being used as a tissue for human use and a tissue for a subject (including dry tissue) impregnated with a chemical agent such as an antimicrobial agent. When the wiping sheet 1 is used in such a product, the air permeability is good and the body fluid diffusion property is excellent as compared with the case of using another wiping sheet.

The surface layer 2 and the back surface layer 3 constituting the wiping sheet 1 may be bonded to each other with an adhesive such as an adhesive, or integrally laminated by various known methods such as a mechanical interlacing method such as a needle-punching interlacing method or a fluid interlacing method (a water-jet interlacing method or an air-jet interlacing method), and preferably integrated by the water-jet interlacing method. Within the range of achieving the effects of the present invention described later, the wipe sheet 1 can be formed in the form of an adhesive nonwoven fabric by bonding the two

layers

2, 3 with an adhesive (adhesive), but when the

fibers

4, 5 forming the two

layers

2, 3 are integrated with each other by hydroentanglement, stiffening of the wipe sheet due to the use of an adhesive can be eliminated, and the laminated webs can be entangled with each other more densely and uniformly as a whole, and a wipe sheet excellent in flexibility and good in skin touch can be obtained. In the case where the wiping sheet 1 is not formed by the fluid-interlacing method, the back surface layer 3 may be subjected to a pressure-heating treatment in order to have an uneven shape.

< method for producing wiping sheet >

Fig. 5 is a side view schematically showing a main part in the manufacturing process of the wiping sheet 1. To explain a main part of the manufacturing process with reference to fig. 5, first, a composite web 73 in which a first web 71 (upper layer) for forming the front surface layer 2 and a second web 72 (lower layer) for forming the back surface layer 3 are laminated is conveyed in the machine direction MD by the jet action of the high-pressure water jet. The composite web 73 is, as an option, guided onto an endless belt-shaped screen 75 as an apertured support after being stabilized by supplying a film of water from a water tank 74. A suction force 76 is applied from below the screen 75 to discharge water, and a high-pressure water jet is ejected from a nozzle 77 provided with a plurality of small holes having a predetermined diameter and pitch from above. A plurality of nozzles 77 are arranged in a direction intersecting the machine direction MD.

The mesh 75 is formed by plain-weaving a plurality of stainless steel wires intersecting each other, for example, a warp wire 75a and a weft wire 75b orthogonal to each other, and has a plurality of openings and a plurality of joint portions 78 where the

wires

75a and 75b intersect each other. In the present manufacturing process, the smoothness of the skin contact surface side of the first web 71 is improved and the skin touch of the surface layer 2 is good by spraying the high-pressure water streams to the first web 71 side, but the high-pressure water streams may be sprayed to the second web 72 side or the high-pressure water streams may be sprayed from both the first web 71 side and the second web 72 side within the range that achieves the effects of the present invention described later. Further, as a preliminary interlacing process, after the composite fiber web 73 is subjected to a needle punching process, a high-pressure water stream process may be performed on one surface or both surfaces. In the joint portion 78, the warp threads 75a and the weft threads 75b overlap each other to form a convex shape toward the composite fiber web 73.

Referring again to fig. 3 to 5, by such high-pressure water stream treatment, the fibers of the first web 71 and the fibers of the second web 72 are interlaced, and among the fibers (short fibers) constituting the second web 72 on the screen 75, the fibers located on the joint portion 78 are moved by the action of the high-pressure water stream jet, whereby the fibers are rearranged on the joint portion 78, and the openings 80 where no fibers are present are formed. In addition, in the second web 72, a plurality of groove portions 82 extending in the machine direction MD and arranged in the cross direction are formed by high-pressure water jets ejected from a plurality of nozzles 77 arranged in parallel in the cross direction, and rib portions 81 located between the groove portions 82 are formed. The plurality of ribs 81 and the plurality of grooves 82 are alternately arranged in the second direction, and the openings 80 are arranged in the grooves 82 at predetermined intervals in the first direction X (intersecting direction), thereby forming an opening row. On the other hand, since the first web 71 to which the high-pressure water jet is directly sprayed is sprayed in a state in which the fiber gaps are relatively small and the long fibers 4 made of extremely fine fibers such as nylon are randomly arranged and the fibers move with each other, the long fibers 4 are not irregularly formed into an uneven shape unlike the second web 72, and the long fibers 4 do not form a plurality of openings 80, and are irregularly drawn into an arc shape and uniformly spread into a mesh shape, and thus it can be said that the first web has a network structure. The long fibers 4 mainly constitute a sheet shape which is intertwined with each other, but may be partially welded.

In the water-jet interlacing method, it is preferable to perform the treatment with a relatively low water pressure, specifically, it is preferable to jet a columnar water flow with a water pressure of 1 to 8MPa to the composite fiber web 73 from a nozzle 77 in which small holes with a hole diameter of 0.1 to 0.5mm are arranged at intervals of 0.2 to 2.0 mm. By performing the treatment with a relatively low water pressure, the first web 71 can maintain the interlacing of the long fibers 4 in a mesh form without being disintegrated, and the second web 2 can be formed with an uneven structure formed by the rib cloths 81 and the groove portions 82 alternately arranged in the second direction Y.

The long fibers 4 in the first web 71 are oriented in the machine direction MD by the production method (e.g., melt blowing method), but when they are interlaced with each other while being randomly distributed, the long fibers 4 draw arcs irregularly, and a network structure that spreads uniformly in a mesh shape is more easily formed. The long fibers 4 and the short fibers 5 are interlaced with each other in the rib portions 81 of the back surface layer 3, and at least a part of the long fibers 4 partially span a part of the plurality of openings 80 in the groove portions 82 of the back surface layer 3.

The wiping sheet 1 having such a laminated structure can be used as a sheet for wiping off sebum or cosmetic powder particles such as ceramics adhered to the skin, for example, as a wet tissue or a cosmetic wiping sheet, or a cover sheet for a cosmetic pad, with the surface 1a being a first wiping surface in a dry state or a wet state. Since the extremely fine long fibers 4 are uniformly spread in a mesh shape on the surface 1a formed by the surface layer 2, when the surface is pressed against the face for wiping, the long fibers 4 forming the mesh edge as the peripheral edge of the mesh can enter the pores to scrape off the cosmetic powder, sebum, and the like by the edge effect, and can be extracted to the inside of the mesh, so that the surface layer 2 can perform a scrubbing action.

In order to exert such a brushing effect, for example, as the fibers constituting the surface layer 2, ultrafine fibers obtained by opening a split composite fiber may be used, but in this case, the surface of the ultrafine fibers generated by opening may be irritated when the skin is wiped. As in the wiping sheet 1 according to the present embodiment, the long fibers 4 made of non-separable ultrafine fibers such as nylon are used for the surface layer 2, whereby such irritation to the skin can be eliminated. In addition, since the long fibers 4 do not have fiber ends on the surface 1a unless they are cut in the manufacturing process of the wiping sheet 1, irritation caused by contact of the fiber ends with the skin can be suppressed.

Further, the back surface layer 3 forming the back surface 1b may also function as a second wiping surface by the plurality of ridge portions 81 and the plurality of groove portions 82 extending in the first direction X being alternately arranged in the second direction Y and the plurality of openings 80 being formed in the groove portions 82. That is, when the back surface 1b is flat without holes and irregularities, dirt such as cosmetic powder and dust is not captured when the user uses the back surface 1b as a wiping surface to the skin, and the dirt cannot be sufficiently wiped. According to the wiping sheet 1 of the present embodiment, since the plurality of holes 80 are formed in the back surface layer 3, the back surface 1b is not flat, and when the back surface 1b is used to wipe the skin, dirt such as cosmetic powder or dust can be captured in the holes 80, and sufficient wiping performance can be exhibited. Accordingly, the user can use the wiping sheet 1 with one of the front surface 1a and the back surface 1b as a wiping surface freely selected. In this way, the back surface layer 3 does not necessarily have a concave-convex shape formed by the plurality of ridge portions 81 and groove portions 82 as long as the back surface 1b side is not flat in the range where both the front and back surfaces of the wiping sheet 1 function as wiping surfaces.

< case of using wiping sheet in Dry State >

Fig. 6 is a perspective view of a cosmetic pad 10 including a backing layer (batt) 20 formed of absorbent fibers and a cover sheet 21 wrapping the backing layer 20 with the wiping sheet 1 as a base material, and fig. 7 is a sectional view taken along line VII-VII of fig. 6. The cover sheet 21 includes: a skin-contacting surface and a non-skin-contacting surface, an outer layer 24 located on the skin-contacting surface side and corresponding to the surface layer 2 of the wiping sheet 1, and an inner layer 23 corresponding to the back layer 3.

The long fibers 4 having low hygroscopicity in the outer layer 24 draw irregular arcs on the skin contact surface of the cosmetic pad 10 and diffuse into a mesh shape, so that the liquid such as cosmetic liquid impregnated from the skin contact surface forms a substantially uniform liquid film uniformly diffused in the skin contact surface of the cosmetic pad 10. Therefore, when the cosmetic pad 10 is impregnated with a liquid detergent to wipe off dirt on the skin, the liquid detergent can be uniformly impregnated into the skin to wipe off the dirt on the entire skin. In addition, when the cosmetic pad 10 impregnated with a relatively large amount of cosmetic liquid is used as a cosmetic packaging sheet, the cosmetic liquid does not permeate the entire skin contact surface, and therefore, a good adhesion to the skin can be exhibited.

Further, since the fine long fibers 4 in the surface layer 2 are arranged in a mesh shape to form a plurality of relatively small fiber gaps, the liquid retention property (liquid retention property) of the liquid such as the cosmetic liquid in the surface layer 2 is excellent as compared with the case where the fibers are densely concentrated without forming the fiber gaps, and is good as compared with the case where the fiber gaps are relatively large or the case where the plurality of openings 80 are formed as in the back layer 3. That is, since the long fibers 4 are formed of hygroscopic fibers having relatively low water absorbability, the liquid enters the fiber gaps without being absorbed by the fibers, and is stably held in the surface layer 2 for a certain period of time by the surface tension. Therefore, even when a relatively small amount of the cosmetic liquid is impregnated into the cover sheet 21, the cosmetic liquid is not instantaneously absorbed into the inner layer 23 or the backing layer 20, and the outer layer 24 is in a wet state for a certain period of time, so that the cosmetic liquid is not impregnated into the surface layer 2 until the cosmetic liquid is impregnated into the surface layer and the surface layer comes into contact with the face, and the skin contact surface is not in a dry state. In the top sheet 2, the long fibers 4 extend in a mesh shape so as to draw an irregular arc, thereby crossing the openings 80 of the back sheet 3 and forming a mesh above the openings 80, whereby the cosmetic liquid impregnated in the top sheet 2 does not directly move from the openings 80 to the backing layer 20, and the good liquid retention property described above can be exhibited.

In the case where the wiping sheet 1 is formed only of the extremely fine long fibers 4, the wiping sheet is excellent in wiping performance, while there is a possibility that the back surface layer 3 formed of the short fibers 5 having a larger average fiber diameter than the long fibers 4 is integrated with the surface layer 2, so that the wiping sheet 1 has appropriate body strength and sheet strength. Therefore, the wiping sheet 1 is prevented from having a large running shape or curling of the surface layer 2 in a dry state or a wet state, and a stable wiping operation can be performed. Further, since the back surface layer 3 has an uneven shape formed by the plurality of ridge portions 81 and the groove portions 82, the bending rigidity in the sheet strength of the wiping sheet 1 is improved as compared with the case where it is flat, and the immersed liquid can be rapidly moved.

As described above, when the wiping sheet 1 is used for the cover sheet 21 of the cosmetic sheet 10, the long fibers 4 are expanded in a mesh shape on the skin contact surface, whereby dirt and the like entering pores can be scraped off, and when the cosmetic liquid is impregnated from the skin contact surface side, a uniformly expanded liquid film is formed, and the skin can be wiped without unevenness. Further, since the inner layer 23 has the uneven structure formed by the plurality of ridge portions 81 and the groove portions 82, appropriate body strength is given to the inner layer 23, wiping operation is stably performed, and the cosmetic liquid or the like transferred to the inner layer 23 is diffused over the entire sheet along the groove portions 82 and is rapidly absorbed into the foundation layer 20 through the plurality of openings 80.

< use in Wet State >

Fig. 8(a) is a perspective view of a container 91 for refilling wet tissues 90 having a wiping sheet 1 as a base material, and fig. 8(b) is a schematic partial side view of a stacked body in which a plurality of wet tissues 90 stored in the container 91 are stacked.

Referring to fig. 8(a), the container 91 has an openable and closable take-out port 93, and the wet sheets 90 folded in a zigzag form and an inverted zigzag form are stored as a stacked body in a state of being alternately stacked, and a part of the wet sheet 90a positioned at the uppermost portion of the stacked body among the wet sheets 90 protrudes from the take-out port 93. When the protruding portion is pulled up, the wet sheet 90a is separated from the overlapped wet sheet 90b and pulled out of the container 91, and a part of the wet sheet 92b protrudes from the outlet 93.

In the wet sheet 90 stored in such a state, similarly to the cosmetic sheet 10, the wiping property is excellent due to the network structure of the long fibers 4 in the surface layer 2, and the back surface layer 3 has appropriate body strength and form retention property, so that the wiping operation can be stably performed. Further, since the back surface layer 3 is mainly composed of the short fibers 5 having water absorption property such as rayon, the wet sheets 90 can be stored in the container 90 while retaining a predetermined amount of wet components such as water and alcohol in advance, and since the plurality of openings 80 are provided, the air permeability in the thickness direction is excellent, and therefore, air does not stagnate between the wet sheets 90 stacked in a wet state.

Referring to fig. 8(b), in the laminated body, in the wet sheet 90 folded in a zigzag shape and overlapped in an inverted zigzag shape, the back surface layer 3 of the wet sheet 90a to be drawn out and the back surface layer 3 of the wet sheet 90b to be drawn out next are brought into contact with each other in an opposed manner. When the back surface layer 3 (back surface 1b) is flat, at the portion where the back surface layers 3 come into contact with each other when the wet sheet 90 is pulled out, the back surface layer 3 of the wet sheet 90a to be pulled out and the back surface layer 3 of the wet sheet 90b to be pulled out next time are smooth, and therefore, a part of the wet sheet 90b may not protrude from the take-out opening 93 to such an extent that it is easy to hold the sheet. In the wet sheet 90 produced by using the wiping sheet 1 according to the present embodiment, since the back surface 1b is not smooth by forming the plurality of openings 80 in the back surface layer 3, the wet sheet 90b to be pulled out next time is pulled, and a part of the wet sheet 90b can be reliably protruded from the outlet 93.

The surface layer 2 and/or the back surface layer 3 of the wiping sheet 1 of the present invention may be formed not as a single layer but as a plurality of layers, and may have a multilayer structure for improving the sheet strength particularly when it is intended to be used in a wet state. In this case, for example, in addition to the surface layer 2 and the back surface layer 3 each having a two-layer structure, in the illustrated example, a fiber web used as the back surface layer 3 may be interposed between fiber webs used as the surface layer 2, or a single back surface layer 3 or a surface layer 2 may be laminated on the surface layer 2/back surface layer 3 having a two-layer structure.

In the present invention, since the content of the long fibers 4 made of the ultrafine fibers in the surface layer 2 is about 60 to 100% by mass, the number of contact points of the wiping sheet 1 with an object to which the wiping sheet is applied is increased as compared with the case where the content is less than about 60%, and the wiping sheet is excellent in touch feeling and adhesiveness to the skin. The long fibers 4 may be fibers dispersed in a state of single fibers, or may be a fiber aggregate (fiber bundle) formed by aggregating a plurality of single fibers into a bundle. When the long fibers 4 are aggregated into a bundle, large dirt can be captured by the bundle, and the extremely fine long fibers 4 forming the bundle can enter pores to pull out small dirt and be captured inside the bundle, so that the wiping property is improved.

Referring to fig. 6 and 7, the structure of the cosmetic pad 10 using the wiping sheet 1 will be further described, in which the cosmetic pad 10 has a first direction S and a second direction R intersecting each other, a first surface 11 and a second surface 12 located on the opposite side thereof, 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 portion 17 and a second end portion 18 spaced apart from each other in the first direction S, and an intermediate portion 19 located between the first end portion 17 and the second end portion 18. In the intermediate portion 19, the width in the second direction R is constant, and in the first and

second end portions

17, 18, both side edges 13, 14 are inclined so that the dimension in the second direction R becomes smaller toward the end edges 15, 16, respectively. The cover sheet 21 is overlapped so as to wrap the cushion layer 20, and in order to maintain such a laminated state, the laminated portions are joined to each other at two joining

portions

45, 46 along both side edges. By holding the laminated state of the cover sheet 21, an openable and closable bag 50 having an opening edge portion 51 extending in the second direction R is formed between the two joining

portions

45 and 46. The size L1 of the cosmetic pad 10 in the first direction S is about 45 to 65mm, the size in the second direction R is about 65 to 85mm, and the size of the middle portion 19 in the first direction S is larger than the sizes of the first and

second end portions

17, 18 in the first direction S.

Preferably, the pad layer 20 has a mass of about 0.2 to 0.4g in the cosmetic pad 10. Preferably, the cushion layer 20 has a lower mass per unit area at the middle portion 19 than at the first and

second end portions

17, 18. The masses per unit area at the first and second ends 17, 18 of the cushion layer 20 may be substantially the same or different, and in the present embodiment, the masses per unit area at the first and second ends 17, 18 are substantially the same. Further, for example, when the cosmetic pad 10 is used by inserting a finger into the pocket 50 from the opening edge 51 thereof by making the mass per unit area at the first end 17 of the backing layer 20 larger than the mass per unit area at the second end 18, the flexibility of the end (first end 17) on the side where the finger is inserted can be improved, and a soft skin touch can be obtained.

The backing layer 20 is a fiber aggregate mainly composed of hydrophilic fibers, and a hydrophobic fiber may be mixed in the fiber aggregate as long as the water absorption required for the backing layer 20 is not hindered. Specifically, the hydrophilic fiber is contained in an amount of about 80 mass% or more. As the hydrophilic fiber, for example, rayon fiber, cotton fiber, acrylic fiber, or the like can be used. As the hydrophobic fibers, for example, synthetic fibers made of synthetic resins such as polyethylene, polyester, and polypropylene, synthetic fiber composite fibers made of these synthetic resins, and the like can be used. In the present embodiment, the cushion layer 20 is formed of a fiber aggregate mainly composed of rayon. When rayon fiber is used as the hydrophilic fiber, the dewatering property when the cosmetic water is used while being impregnated can be improved as compared with the case of using cotton fiber.

The fibers forming the outer layer 24 are long fibers 4, and when the fiber length is relatively large, for example, larger than the dimension of the cosmetic sheet 10 in the first direction S and/or the second direction R, the end portions of the fibers are not present on the first and

second surfaces

11 and 12. When the outer layer 24 is formed using the short fibers 5 having the fiber ends on the first and

second surfaces

11 and 12, the end portions may contact the skin and cause skin irritation when the cosmetic pad 10 is used, but by using the long fibers 4 that are continuous on the first and

second surfaces

11 and 12 so that the end portions are not present except the outer peripheral edge portion of the cosmetic pad 10, the skin feel can be improved as compared with the case where the short fibers are used. In the cosmetic sheet 10 of the present embodiment, since the joint portions 44 are formed on the inner sides of the respective side edges 13 and 14 of the cosmetic sheet 10, which are the cutting lines of the covering sheet 21, the distal end portions of the long fibers 4 are not present in the cosmetic liquid application region defined by each of the joint portions 44 and the two

end edges

15 and 16 on the second surface 12, and a good touch feeling can be obtained.

In the case where the inner layer 23 includes a hydrophobic thermoplastic fiber, since the hygroscopicity of the inner layer 23 is lowered, the effect of introducing the cosmetic liquid or the like held in the outer layer 24 is suppressed, and the liquid retention on the skin contact surface side can be further improved. Further, when the cover sheets 21 laminated at the respective joining

portions

45, 46 are joined by embossing/debossing by heat or ultrasonic waves, it is preferable that the joining strength is lowered if the inner layer 23 of the inner layer 23 and the outer layer 24 facing each other is a non-melting rayon when the sheets are joined while being melted. By the inner layer 23 containing thermoplastic fibers, welding of the inner layer 23 and the outer layer 24 becomes easy, the joint strength at the joint 44 is improved, and peeling of the portion can be prevented in use.

[ examples ]

The following specifically describes examples of the present invention, but the present invention is not limited to the following examples.

[ example 1]

Wiping sheet: a thickness of 0.25mm and a mass per unit area of 30g/m²

Surface layer: thickness of 0.09mm and mass per unit area of 10g/m²，

Melt-blown nonwoven fabric (nylon 6:100 mass%),

average fiber diameter of the long fibers was 4 μm

Back layer: thickness of 0.16mm and mass per unit area of 20g/m²，

Spunlaced nonwoven fabrics (staple fiber: rayon, 80 mass%,

a heat-fusible fiber; 20% by mass),

the average fiber diameter of the staple fibers (rayon and heat-fusible fibers) was 16 μm

[ example 2]

Wiping sheet: a thickness of 0.25mm and a mass per unit area of 30g/m²

Surface layer: thickness of 0.09mm and mass per unit area of 10g/m²，

Melt-blown nonwoven fabric (nylon 6:100 mass%),

average fiber diameter of the long fibers was 4 μm

Back layer: thickness of 0.16mm and mass per unit area of 20g/m²，

Rayon fiber (rayon; 100 mass%),

average fiber diameter of staple fibers (rayon) 15 μm

Comparative example 1

Wiping sheet (single layer): a thickness of 0.27mm and a mass per unit area of 30g/m²，

Melt-blown nonwoven fabric (nylon 6:100 mass%),

average fiber diameter of the long fibers was 4 μm

Comparative example 2

Wiping sheet (single layer): a thickness of 0.25mm and a mass per unit area of 30g/m²，

A spunlaced nonwoven fabric (cotton: 100 mass%),

average fiber diameter of 15 μm

Comparative example 3

A spunlaced nonwoven fabric (rayon: 100 mass%),

average fiber diameter of 15 μm

In each of examples and comparative examples, as surface characteristics, a wiping test and a functional test were performed in addition to measurement of an average surface friction coefficient (MIU), an average variation in surface friction coefficient (MMD), and an average variation in surface roughness (SMD). The measurement results and test results are shown in table 1. The characteristic values for the nonwoven fabric, which are characteristic values indicating the skin feel, were measured for the generally known KES manufactured by カト - テック (reference: standardization and analysis of evaluation of wind turbine blade (second edition), the authors, sho-10.55 years).

[ Table 1]

The measurement methods for the measurement items shown in table 1 and the evaluation criteria for the respective test items are as follows. Further, the test results were evaluated by using A (excellent), B (good), C (general) and D (poor).

< method for measuring surface Properties >

The surface properties were measured by using KES-FB4, manufactured by カト - テック, in a range of 1.0 cm. times.1.0 cm in the cosmetic material application region of each sample as a sample, and by placing a part of the sample on a test bed having a metal surface. For the measurement of the surface roughness, a load of 10gf was applied to the surface of the sample, and a contact terminal having a width of 0.5cm, in which a piano wire having a diameter of 0.5mm was wound in a coil shape, was used as the contact terminal. In the measurement of the surface friction, a force of 50gf was applied by a weight to a contact having 10 piano wires with a diameter of 0.5mm, and the contact surface of the contact was pressed against the sample. In the measurement of the surface friction and the surface roughness, the sample was moved horizontally by 2cm at a speed of 0.1cm/sec, and a uniaxial tension of 20gf/cm was applied to the sample. Characteristic values are measured for each sample in the first direction X and the second direction Y, and an average value is obtained.

Reference to evaluation

1. Value of mean surface coefficient of friction (MIU)

A: 0.25 or more

B: more than 0.20 and less than 0.25

C: more than 0.15 and less than 0.20

D: in addition to this

2. Mean deviation of surface coefficient of friction (MMD)

A: 0.0080 or less

B: more than 0.0080 and less than 0.0090

C: more than 0.0090 and less than 0.0100

D: over 0.0100

3. Value of mean deviation of surface roughness (SMD) [ mum ]

A: 4.0 or less

B: more than 4.0 and less than 4.5

C: more than 4.5 and 5.0 or less

D: over 5.0

< wiping test >

The wiping sheet 1 of the present invention and the wiping sheet of the comparative example were used to perform a wiping test of a cosmetic product (foundation). As the test apparatus, a frictional wear measuring apparatus TL201Ts manufactured by Kabushiki Kaisha トリニティ - ラボ was used. Further, the wiping sheet and the wiping sheet 1 of the comparative example as a sample were tested in a state where a liquid such as a cosmetic liquid was not applied. First, 0.02g of a cosmetic was applied to the surface of a rectangular glass sheet having a width of 26mm and a length of 90mm in a circular shape having a diameter of 13mm as a test piece, with the position 20mm from the edge in the longitudinal direction as the center. Next, the wiping sheet 1 as a sample was held by a pad-dedicated jig (depth 20mm, width 70mm) of the test apparatus so that the surface 1a thereof became an exposed surface, and after the application of the cosmetic, a constant load was applied to the dedicated jig (to the wiping sheet in contact with the test sheet) for the test sheet after the lapse of 40 minutesArea of the sheet 1 was 5.2cm²A load of 100 g) was applied while the cosmetic was wiped while moving 60mm from the edge of the test piece at a moving speed of 2.5 mm/s. In addition, in the present measurement, as a cosmetic, a widely distributed foundation (for example, a cosmetic containing a preservative, a surfactant, an ultraviolet absorber, a tar pigment, an artificial perfume, and the like as components) is generally used.

Next, the surface of the test piece after wiping the cosmetic was read by a scanner (GT-X750, manufactured by セイコ - エプソン), and then the image was read by image software (Adobe Photoshop Elements 3.0), and histogram processing was performed by Histgram Analysis software to perform binarization processing. The binarization-processed value of the test piece before the wiping of the cosmetic was set to 100, and the binarization-processed value of the test piece after the wiping was expressed by a ratio as a wiping rate. The number of samples in each example was N-3, and the average value thereof was calculated.

< evaluation method >

A: the wiping rate is more than 90 percent

B: the wiping rate is more than 80 percent and less than 90 percent

C: the wiping rate is more than 70 percent and less than 80 percent

D: the wiping rate is less than 70 percent

< evaluation of function >

Each of the 12cm × 12cm wiping sheets was soaked with distilled water in an amount of 3 times the mass of the sheet to prepare wet sheets, and the "softness", "smoothness", and "wiping feeling" of the wet sheets when 10 female participants wiped foundation applied to the face with each wet sheet were evaluated in four grades.

1. Softness

A: softness

B: slightly soft

C: nothing to do

D: is not soft

2. Smooth feeling

A: has a smooth feeling

B: slightly smooth feeling

C: nothing to do

D: has no smooth feeling

3. Feeling of wiping

A: has wiping feeling

B: slightly feel a wiping feeling

C: nothing to do

D: no feeling of wiping

< measurement results >

As shown in table 1, the wiping sheets 1 of examples 1 and 2 had an average surface friction coefficient (MIU) of 0.25 or more, an average deviation of surface friction coefficient (MMD) of 0.008 or less, and an average deviation of surface roughness (SMD) [ unit: μ m ] is 4.0 or less. On the other hand, the wiping sheet of comparative example 1 has an MIU of 0.25 or less, an MMD of 0.008 or less, and an SMD of 5.0 or more, the wiping sheet of comparative example 2 has an MIU of less than 0.20, an MMD of 0.008 or less, and an SMD of 4.0 or less, and the wiping sheet of comparative example 3 has an MIU of less than 0.20, an MMD of more than 0.100, and an SMD of 5.0 or less. In the wiping test, the wiping sheets 1 of examples 1 and 2 and the wiping sheet of comparative example 1 each had a wiping rate of 90% or more, and showed a high wiping rate exceeding 90% in a state where no cosmetic liquid was applied. On the other hand, in the wiping sheets of comparative examples 2 and 3, the wiping rate was less than 80%.

As a result of such measurement and evaluation, in the wiping sheet 1 of examples 1 and 2, the long fibers 4 drawn irregular arcs on the surface 1a side and spread in a mesh shape, whereby the surface 1a side was relatively smooth, and when a liquid such as a cosmetic liquid was supplied to the surface 1a side, the liquid spread uniformly over the entire surface 1a to form a uniform liquid film. Further, since the wiping sheet 1 of examples 1 and 2 includes the long fibers 4 made of ultrafine fibers, a large number of small edge portions are formed on the surface 1a side, and the wiping sheet has a relatively high frictional resistance, and therefore, the wiping sheet is excellent in workability and can scrape out fine dirt entering pores by wiping.

As described above, the surface 1a of the wiping sheet 1 of examples 1 and 2 was formed of the long fibers 4 made of ultrafine fibers, was relatively smooth, and had a relatively high frictional resistance, so that the evaluation of "softness", "smooth feeling", and "wiping feeling" was "a" in the functional evaluation, and the sheet characteristics of the wiping sheet 1 were actually confirmed as the feeling of use. On the other hand, the wiping sheets of comparative examples 1 to 3 had relatively uneven surfaces and relatively low frictional resistance, and therefore, a uniform liquid film could not be formed as in examples 1 and 2, and a sufficient scrubbing function could not be exhibited, and the evaluation was not "a" in all items of the function evaluation.

As the material constituting the wiping sheet 1 according to the present invention, various known materials generally used in such articles can be used without limitation, in addition to the materials described in the specification. In the description and claims, the terms "first", "second", and "third" are used merely to distinguish similar components, positions, and the like.

The disclosure of the present invention described above can be summarized as at least the following matters.

A wiping sheet comprising a surface layer composed mainly of hygroscopic long fibers having an average fiber diameter of 10 μm or less and a back layer composed mainly of short fibers having an average fiber diameter exceeding 10 μm, wherein the long fibers are irregularly formed in an arc shape on the surface layer and uniformly spread in a mesh shape, and a plurality of openings are formed in the back layer in the first direction, and the long fibers span at least a part of the openings.

The invention disclosed in the above paragraph may include at least the following embodiments.

(1) The back surface layer further includes a plurality of groove portions and a plurality of ridge portions extending in the first direction, the groove portions and the ridge portions are alternately arranged in the second direction, and the plurality of openings are formed in the groove portions.

(2) The density of the surface layer is 0.05 to 0.2g/cm³The thickness of the surface layer is about 20 to 60% of the thickness of the back layer.

(3) The aforementioned surface layer has a wipe rate of at least 80% in a dry state.

(4) The surface has an average surface friction coefficient (MIU) of 0.25 or more and an average surface roughness deviation (SMD) of 4.0 μm or less.

(5) The long fiber is nylon.

(6) The short fibers are fibers having a higher moisture absorption than the long fibers.

(7) The short fibers are at least one of cellulose fibers including rayon and cotton.

(8) The surface layer and the back layer are water-jet nonwoven fabrics integrated by a water-jet interlacing method.

Description of the reference numerals

1 wiping sheet

2 surface layer

3 back layer

4 long fiber

5 short fiber

80 open pore

81 rib part

82 groove part

thickness dimension of t2 surface layer

t3 thickness dimension of backside layer

X first direction

Y second direction

Claims

1. A wiping sheet having a first direction and a second direction intersecting the first direction, a surface layer mainly composed of long hygroscopic fibers having an average fiber diameter of 10 μm or less, and a back layer mainly composed of short fibers having an average fiber diameter of more than 10 μm,

the long fibers have a fiber length of 30 to 200mm, and the short fibers have a fiber length smaller than that of the long fibers,

the long fibers are irregularly drawn in an arc shape and uniformly spread in a mesh shape to form a plurality of small fiber gaps in the surface layer, and a plurality of openings are formed in the back layer and arranged in the first direction, the long fibers span at least a part of the openings, and a mesh is formed above the openings.

2. The wiping sheet of claim 1, wherein the back layer further comprises a plurality of grooves and a plurality of ribs extending in the first direction, the grooves and the ribs being alternately arranged in the second direction, and the plurality of openings are formed in the grooves.

3. The wiping sheet according to claim 1 or 2, wherein the density of the surface layer is 0.05 to 0.2g/cm³The thickness of the surface layer is 20 to 60% of the thickness of the back layer.

4. A wiping sheet according to claim 1 or 2, characterized in that the wiping rate of the aforementioned surface layer in the dry state is at least 80%.

5. A wiper blade according to claim 1 or 2, wherein the average surface friction coefficient (MIU) of the surface is 0.25 or more and the average deviation (SMD) of the surface roughness is 4.0 μm or less.

6. A wiping sheet according to claim 1 or 2, characterized in that the aforementioned long fibers are nylon.

7. The wiping sheet according to claim 1 or 2, wherein the short fibers are fibers having a higher moisture absorption than the long fibers.

8. A wiping sheet according to claim 1 or 2, characterized in that the short fibers in the backing layer are cellulose fibers.

9. The wiping sheet according to claim 1 or 2, wherein the surface layer and the back layer are a water-jet-net nonwoven fabric integrated by a water-jet-interlacing method.