TW201920793A - Wiping sheet and method for manufacturing same - Google Patents

Abstract

A wiping sheet (10) is provided with a fiber aggregate formed by interlacing first fibers (20) and second fibers (40) having a smaller diameter than the first fibers (20), and has a first surface (50Y) serving as a wiping surface and a second surface (50X) positioned on the opposite side thereto. The abundance of the second fibers (40) is greater at the first surface than at the second surface. A plurality of protruding portions (50A) are formed on the first surface (50Y) side, and in apex portions (50T) of the protruding portions (50A), the abundance of the first fibers (20) in the apex portion (50T) relative to all the fibers forming the protruding portion (50A), is greater than the abundance of the second fibers (40) in the apex portion (50T) relative to all the fibers forming the protruding portion (50A). In a skirt portion (50B) of the protruding portions (50A), the abundance of the second fibers (40) in the skirt portion (50B) relative to all the fibers forming the protruding portion (50A) is greater than the abundance of the first fibers (20) in the skirt portion (50B) relative to all the fibers forming the protruding portion (50A).

Description

Wiping sheet and manufacturing method thereof

The present invention relates to a wiping sheet and a manufacturing method thereof.

Various attempts have been made to improve the function of the non-woven fabric by forming an uneven structure on the surface of the non-woven fabric. For example, Patent Document 1 describes a non-woven fabric which is composed of an electrospun product of at least one kind of high molecular fiber among nanofibers and microfibers, and has a concave-convex minute pattern at a specific position on a plane. It is described in the same literature that the non-woven fabric can be highly functional with the shape specificity obtained by using the uneven pattern structure to improve the cell affinity and material structure, and also can adjust the biological function.

Patent Document 2 describes a non-woven fabric containing extremely fine fibers of 1 dtex or less and having unevenness on the surface. The surface of the non-woven fabric includes a plurality of fiber bundles intertwined with each other, and a depression in the vicinity thereof. Furthermore, the number of ultrafine fibers in the fiber bundle becomes larger than the number of ultrafine fibers in the depression. It is described in the same document that the nonwoven fabric is excellent in bulkiness, is soft, and has a soft touch when it comes in contact with a target surface. [Prior Art Literature] [Patent Literature]

Patent Document 1: Japanese Patent Laid-Open No. 2006-328562 Patent Document 2: Japanese Patent Laid-Open No. 2009-13544

The present invention provides a wiping sheet comprising a first fiber and a second fiber having a smaller diameter than the first fiber, and a fiber aggregate formed by interweaving these fibers, the first surface serving as a wiping surface, And the second face on the opposite side of the first face. The presence ratio of the second fiber becomes higher on the first surface than on the second surface. A plurality of convex portions are formed on the first surface side. The presence ratio of the first fiber in the top of the entire fiber constituting the convex portion becomes higher than the presence ratio of the second fiber. The presence ratio of the second fiber in the foot portion with respect to the entire fiber constituting the convex portion becomes higher than the presence ratio of the first fiber.

In addition, the present invention provides a method for manufacturing a wiping sheet. As a preferred method for manufacturing the wiping sheet, a fiber assembly of a first fiber and a fiber assembly of a second fiber having a smaller diameter than the first fiber are used. The laminated body is arranged so that the fiber assembly of the second fiber faces the convex-portion forming member having a plurality of openings. In this state, a water stream is blown from the side of the fiber assembly of the first fiber, the first fiber and the second fiber are entangled, and the fiber assembly located in the opening portion is caused to protrude in the opening portion.

As an article for wiping hard surfaces such as floor and furniture, a wiping sheet containing a non-woven cloth is often used. The above-mentioned Patent Document 1 describes the technology of the non-woven fabric, but the non-woven fabric described in the same document is intended to be applied to medical devices such as regenerative medicine, and does not mention the functionality of the non-woven fabric in the case of wiping or cleaning.

When a non-woven fabric having a concave-convex structure described in Patent Document 2 is used as a cleaning product, the non-woven fabric contains fine-diameter fibers, and the frictional resistance between the non-woven fabric and the object to be cleaned is increased, and the non-woven fabric has poor operability during cleaning. Situation.

Therefore, the present invention relates to a wiping sheet which reduces frictional resistance with an object to be wiped and improves operability during wiping.

Hereinafter, the wiping sheet of the present invention will be described based on its preferred embodiment. In the present invention, the so-called wiping means the meaning of both cleaning and wiping, such as the cleaning of buildings including floors, walls, ceilings, and pillars, the cleaning of construction tools or supplies, the wiping of articles, and the body and the body. Wiping of appliances, etc.

The wiping sheet of the present invention includes a fiber aggregate. The fibers constituting the fiber assembly include at least a first fiber and a second fiber having a smaller diameter than the first fiber. The first fibers and the second fibers are the first fibers, the second fibers, and the first fibers and the second fibers are entangled to form the fiber assembly. A wiping liquid may be carried on the fiber assembly. The wiping liquid and its supporting method are explained in detail below. In addition, in this specification, when it is abbreviated as a "wiping sheet", it means the person who carried the wiping liquid and the person who does not carry the wiping liquid according to the context.

The fiber assembly system for wiping the sheet 10 is a composite fiber assembly composed mainly of the intersection of the first and second fibers. Here, the wiping surface of the wiping sheet 10 is also called a surface or a 1st surface, and the surface opposite to a wiping surface is called a back surface or a 2nd surface.

In FIG. 1, the main part of the longitudinal cross section of one embodiment of the wiping sheet of this invention is expanded and shown. As shown in the figure, the wiping sheet 10 includes a first fiber 20 and a second fiber 40. The wiping sheet 10 has a first surface 50Y and a second surface 50X located on the opposite side to the first surface 50Y. The first surface 50Y of the wiping sheet 10 is provided as a wiping surface when the wiping sheet 10 is used. As shown in FIG. 1, on the upper side of the figure, there is a fiber assembly of the second fiber 40 as a fiber with a smaller fiber diameter, which is a wiping surface. Therefore, the lower side of the figure is the opposite side and the back side of the wiping surface.

The wiping sheet 10 projects from the second surface 50X toward the first surface 50Y, thereby forming a convex portion 50A. A plurality of convex portions 50A are formed throughout the surface direction of the wiping sheet 10. The convex portion 50A has a shape in which the first surface 50Y of the wiping sheet 10 is raised from the flat surface 50Y ′. On the second surface 50X side, a region corresponding to the convex portion 50A is recessed from the flat surface 50X ′ of the second surface 50X toward the first surface 50Y to form a concave portion 50C. By the method of manufacturing the wiping sheet 10, the entire area of the second surface 50X can be made flat. In addition, in this specification, the description about the 1st surface 50Y (wiping surface) is a thing which does not contain the convex part 50A.

Each convex portion 50A is a solid body whose interior is filled with the first fiber 20 and / or the second fiber 40. The shapes and sizes of the convex portions 50A may be the same or different. Considering the ease of manufacturing the wiping sheet 10, it is preferable that the shape and size of each convex portion 50A be the same.

Each convex portion 50A may be regularly arranged on the first surface 50Y side of the wiping sheet 10 or may be arranged irregularly. When each convex part 50A is arrange | positioned regularly on the 1st surface 50Y, it can arrange | position regularly along the longitudinal direction of the wiping sheet 10, and / or the width direction, for example. In any of the cases where the convex portions 50A are regularly and irregularly arranged, since a plurality of convex portions 50A are formed on the first surface 50Y side as the wiping surface, the wiping operation using the wiping sheet 10 In this case, the frictional force between the wiping target surface and the wiping sheet 10 can be effectively reduced, and the wiping operation can be easily performed.

As shown in FIG. 1, when the wiping sheet 10 is viewed in the longitudinal section, the locations where the first fibers 20 and the second fibers 40 are present are unevenly distributed. Specifically, the existence ratio of the second fibers 40 of the wiping sheet 10 is such that the first surface 50Y as the wiping surface becomes higher than the second surface 50X as the surface opposite to the wiping surface. By adopting this configuration, in combination with forming a plurality of convex portions 50A on the first surface 50Y side, the wiping effect of the wiping sheet 10 can be improved.

As described above, the existence ratio of the second fibers 40 of the wiping sheet 10 is higher on the wiping surface than on the side opposite to the wiping surface. In addition, when focusing on the first surface 50Y as the wiping surface, the convex portion 50A formed on the first surface 50Y side is at the top portion 50T, with respect to the first fiber 20 in the top portion 50T of the entire fiber constituting the convex portion 50A. The presence ratio becomes higher than the presence ratio of the second fiber 40. On the other hand, in the foot portion 50B of the convex portion 50A, the presence ratio of the second fiber 40 in the foot portion 50B of the entire fiber constituting the convex portion 50A becomes higher than the existence ratio of the first fiber 20. When the existence ratio of the first and second fibers 20 and 40 constituting the convex portion 50A becomes such a situation, it has been found that the frictional force between the wiping target surface and the wiping sheet 10 can be effectively reduced.

The friction between the wiping target surface and the wiping sheet 10 is preferably a pressure of 55 N / m ² applied to the wiping sheet 10 having a size of 10 cm × 25 cm, and the resistance when wiping the wiping target surface is 10 N. Hereinafter, it is more preferably 5 N or less, and even more preferably 4 N or less. The lower limit of the resistance is not particularly limited. The lower the value, the better. If the resistance is as low as about 0.8 N, the wiping operation can be performed smoothly.

The measurement of the resistance during wiping is specifically performed by the following method. A crocodile-type clamp is installed at the front end of the tension gauge (RX-20, manufactured by Aikoh Engineering), and a Quickle wiper (manufactured by Kao Corporation) with a wiper sheet having a size of 285 mm x 205 mm is mounted on the clamp. ) 'S head. The maximum load recorded by the tensile pressure meter when the head was scanned on the floor (Conbit new advance101, manufactured by WOODONE Corporation) at a speed of 1 cm / sec for 1 m was measured as resistance.

The top 50T of the convex portion 50A is a region from the vertex of the convex portion 50A to (1/3) H when the height of the convex portion 50A is set to H. On the other hand, the so-called foot portion 50B of the convex portion 50A is a region from the flat surface 50Y ′ to (1/3) H of the first surface 50Y.

From the viewpoint of more effectively reducing the friction between the surface to be wiped and the wiping sheet 10, the existence ratio of the first fibers 20 and the second fibers 40 in the top portion 50T of the convex portion 50A is preferably relative to the constituent convex portions. The entire fiber of the portion 50A is more than three times as large as the first fiber based on the number of fibers. From the same viewpoint, the existence ratio of the first fiber 20 and the second fiber 40 in the foot portion 50B of the convex portion 50A is preferably relative to the entire fiber constituting the convex portion 50A, and the second fiber is based on the number of fibers as The number of the first fiber is twice or more.

The frictional force between the wiping target surface and the wiping sheet 10 may also depend on the shape of the convex portion 50A. From the viewpoint of reducing friction more effectively, the width W of the convex portion 50A is preferably 400 μm or more, more preferably 800 μm or more, and even more preferably 900 μm or more. The width W is preferably 10 mm or less, more preferably 8 mm or less, and even more preferably 5 mm or less. The width W is preferably 400 μm or more and 10 mm or less, more preferably 800 μm or more and 8 mm or less, and more preferably 900 μm or more and 5 mm or less. As shown in FIG. 1, the width W is measured from a position where the convex portion 50A of the flat surface 50Y ′ from the first surface 50Y of the wiping sheet 10 starts to rise as a starting point. When focusing on one convex portion 50A, when the measured width W of the convex portion 50A is different in an arbitrary direction, the width W of the convex portion 50A means the widest width measured. When looking at the plurality of convex portions 50A, and when the measured widths of the convex portions 50A are different, the width W of the convex portions 50A refers to the arithmetic mean of the widths of the convex portions 50A of the measurement target. .

From the same viewpoint, the height H of the convex portion 50A is preferably 110 μm or more, more preferably 500 μm or more, and even more preferably 900 μm or more. The height H is preferably 25 mm or less, more preferably 20 mm or less, and even more preferably 18 mm or less. The height H is preferably 110 μm or more and 25 mm or less, further preferably 500 μm or more and 20 mm or less, and more preferably 900 μm or more and 18 mm or less. As shown in FIG. 1, the height H is a distance from the flat surface 50Y ′ of the first surface 50Y of the wiping sheet 10 to the vertex of the convex portion 50A. When focusing on the plurality of convex portions 50A, when the height of each convex portion 50A is different, the height of the convex portion 50A refers to the arithmetic mean of the height of each convex portion 50A of the measurement target.

There may be a case where the formation density of the convex portion 50A on the first surface 50Y side also affects the friction between the wiping target surface and the wiping sheet 10. From the viewpoint of reducing friction more effectively, when drawing an imaginary circle with a diameter of 20 mm at any position on the first surface 50Y, the number of convex portions 50A existing in the imaginary circle is preferably 10 or more More preferably, it is 15 or more, More preferably, it is 20 or more. The number of the convex portions 50A is preferably 60 or less, more preferably 50 or less, and even more preferably 40 or less. The number of the convex portions 50A is preferably 10 or more and 60 or less, further preferably 15 or more and 50 or less, and more preferably 20 or more and 40 or less.

The wiping sheet 10 of the present invention can be used as a dry type without carrying a wiping liquid (hereinafter, this state is also referred to as a "dry wipe sheet"), and can also be carried as a wet type. A state of the wiping liquid (hereinafter, this state is also referred to as a "wet wipe sheet"). When the wiping sheet 10 of the present invention is a wet wiping sheet, it is preferable that the wiping liquid is carried on at least the fiber assembly on the second surface side. Moreover, the so-called wiping surface carries the wiping liquid at least on the fiber assembly located on the second surface side, and the fiber assembly on the opposite side of the wiping surface includes the wiping liquid, and also includes the fiber assembly also on the wiping surface The body contains a wiping liquid in its gap. Furthermore, it is preferable that the amount of the wiping liquid to be supported is a large amount of the fiber assembly supported on the opposite side of the wiping surface.

In particular, when the wiping sheet 10 of the present invention is a wet wipe sheet, in addition to forming a plurality of the above-mentioned convex portions 50A, the first fibers 20 and the first fibers 20 and The existence ratio of 2 fibers 40, the width W or height H of the convex portion 50A on the first surface 50Y side, and / or the formation density of the convex portion 50A satisfy a specific range, thereby reducing the frictional resistance effect during wiping. Furthermore, it is advantageous in a more obvious aspect.

From the viewpoint of further improving the wiping effect of the wiping sheet 10 in combination with the formation of a plurality of convex portions 50A, and in the case where the wet wiping sheet 10 is used, a large and stable load of the wiping liquid can be carried out, In the surface of the wiping sheet 10 that also includes voids, the area ratio of the second fibers in the wiping surface is preferably 40% or more and 99% or less, more preferably 45% or more and 95% or less, and even more preferably Above 50% and below 90%. On the other hand, the area ratio of the second fiber in the surface opposite to the wiping surface is preferably 0% or more and 55% or less. The area occupied by the second fibers in the wiping surface is obtained, for example, by measuring the area occupied by fibers having a smaller fiber diameter from an image or a photograph obtained by photographing the wiping surface. Hereinafter, the area occupied by the fibers can be determined in the same manner as described above. Therefore, the area ratio is a value obtained by dividing the area occupied by the fiber by the area to be measured. Furthermore, in the case of%, it becomes 100 times the value divided by.

Here, for example, the remaining 1% of 99% of the upper limit of the area ratio of 40% to 99% is a void. This space is necessary to release the wiping liquid to the wiping surface when the wet wiping sheet 10 is used. By adjusting the ratio of the voids, especially when the wet wipe sheet 10 is used, the amount of the wiping liquid released for wiping off the stains on the surface of the object to be wiped can be suppressed to a necessary amount, even when wiping hard. In addition, by setting the area ratio of the second fibers in the surface opposite to the wiping surface as described above, the number of voids is increased, and the load of the wiping liquid in the wet wiping sheet 10 is increased. If the area ratio of the second fibers in the wiping surface is too small, the wiping liquid is released to a required amount or more. Therefore, the wipeable area becomes small.

The wiping sheet 10 is preferably on a plane parallel to the wiping surface, and the area ratio occupied by the second fibers 40 faces the thickness direction on the opposite side of the wiping surface, and is reduced stepwise, curvilinearly, or in a combination thereof. In particular, the thickness of the wiping sheet 10 is set to 50% or more and 100% or less by the surface opposite to the wiping surface, and the area ratio occupied by the second fiber 40 is set to 50% or more and 100% or less. When the wet wipe sheet 10 is used, the load of the wipe liquid can be increased. Here, the ratio of the thickness described above in which the area ratio occupied by the second fiber 40 is in the range of 50% to 100% is preferably 1% to 90%, and more preferably 5% to 70%. , And more preferably 7% or more and 50% or less. Furthermore, by setting the ratio of the preferable thickness as described above, when the wet wiping sheet 10 is used, a necessary amount of the wiping liquid released for wiping the stain on the surface of the wiping target can be released. The thickness of the wiping sheet 10 is, as shown in FIG. 1, the distance T from the surface opposite to the wiping surface to the vertex of the convex portion 50A.

Here, in order to obtain internal information of the wiping sheet 10, a confocal laser microscope may be used. By using a confocal laser microscope, the spectrum inside the sample can be obtained. For example, by performing Raman imaging of the sample in the depth direction, the component distribution inside the sample can be observed without damage.

The wet wipe sheet 10 includes at least two layers of a liquid retaining layer carrying a wipe liquid and a release layer of the wipe liquid, and the release layer includes a wipe surface. In particular, in order to carry a large amount of wiping liquid, as described above, the thickness of the wiping sheet 10 is set to 50% to 100% from the surface opposite to the wiping surface, and the area ratio occupied by the second fibers is set It is 1% or more and 100% or less. Thereby, it can be set as the liquid retaining layer which carries a large amount of wiping liquid. On the other hand, the release layer includes a portion other than the liquid retaining layer of the wiping surface.

In the wiping sheet 10, the capillary pressure on the wiping surface side is preferably higher than on the opposite side of the wiping surface. Thereby, especially when it is used as the wet wiping sheet 10, the amount of the wiping liquid released for wiping off stains on the surface of the wiping target can be controlled to a necessary amount even when wiping vigorously during wiping. Therefore, in the case of a large wiping area such as a small rug, carpet, or floor, there is no need to change to a new wiping sheet 10 during the wiping, or the number of replacements can be reduced.

Here, it is known that the capillary pressure depends on the following relationship. Pc = 2kγ _L / r × cosθ where Pc is the capillary pressure (N / m ² ) of the fiber assembly, γ _L is the surface tension of the liquid (N / m), and θ is the contact angle between the fiber and the liquid (rad) , R is the fiber diameter (m), and k is the correction factor.

The Pc derived from the above formula is a value using a summary statistic derived from the measurement of the fiber aggregate. To determine Pc, the surface tension of the liquid, the fiber diameter, the contact angle between the fiber and the liquid, and the correction factor must be determined. The surface tension is an average value obtained by measuring an automatic surface tensiometer based on a flat plate method such as DY-200 manufactured by Kyowa Interface Science Co., Ltd. under an environment of 20 ° C and 65% R.H. The fiber diameter was an average value obtained by observing with a scanning electron microscope at an observation magnification of 350 times, measuring 30 pieces per observation, randomly observing a total of 5 locations, and measuring the fiber diameter of 150 pieces. The contact angle between the fiber and the liquid is identified by Fourier transform infrared spectroscopy (FTIR). The constituent fibers of the fiber assembly are measured, and the contact angle on a resin plate of the same composition is measured. Specifically, a full-automatic contact angle meter such as DMo-901 manufactured by Kyowa Interface Science Co. was used to measure the contact angle at 5 positions on the plate at the time of 3 seconds after 1 μL dropwise addition, and set the average value. . In addition, when there are materials of a plurality of fibers, the contact angle is measured in the same way for each material, and as the value in the calculation of Pc, a value obtained based on the weighted average contact angle of the surface area ratio of each fiber component is set. Is θ in the formula. The correction coefficient is determined by measuring the Klemm water absorption as specified in JIS P 8141. The water absorption weight of the liquid is determined based on the water absorption height. The water absorption weight is divided by the total amount of the capillary cross-section that constitutes the nonwoven fabric. Measure Pc in this way and calculate the correction coefficient k.

As is clear from the above formula, the smaller the fiber diameter is, the higher the capillary pressure becomes. In the wiping sheet 10, the fiber diameter is reduced to increase the capillary pressure on the wiping surface side.

The fiber-based fibers constituting the wiping sheet 10 have at least two fibers having different diameters. The fibers are independent, represented by polyester, polyamide, polyolefin, cellulose fibers, or fibers using various metals, glass, and minerals as raw materials. Among them, polyester, polyamide, polyolefin, and cellulose fibers are preferred.

As long as the polyester has a structure having an ester bond in the polymer main chain, any polyester may be used. Examples include: polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN) Polybutylene naphthalate (PBN).

Polyolefin is obtained from a monomer having an ethylenically unsaturated group. Examples include polyethylene, polypropylene, ethylene-propylene copolymer, polyvinyl acetate, ethylene-vinyl acetate copolymer, cyclic acetals of polyvinyl alcohol, and acrylic resins (including acrylic resins and methacrylic resins). , Polyvinyl chloride. The polyolefin is as described above, and either a homopolymer or a copolymer may be used.

Any polyamine may be used as long as it has a structure having a amine bond in the polymer main chain. Examples include polycondensed nylon such as nylon 6, nylon 11, nylon 12, nylon 66, nylon 610, nylon 612, nylon 6T, nylon 6I, nylon 9T, and nylon M5T. In addition, polyamines obtained using the following diamine components and dicarboxylic acid components can be mentioned.

Examples of the diamine component include tetramethylenediamine, pentamethylenediamine, 2-methylpentanediamine, hexamethylenediamine, heptamethylenediamine, and octamethylenediamine , Unamethylene diamine, decamethylene diamine, dodecamethylene diamine, 2,2,4-trimethyl-hexamethylene diamine, 2,4,4-trimethyl hexamethylene Aliphatic diamine compounds such as methylene diamine. Further examples include 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, 1,3-diaminocyclohexane, 1,4- Diaminocyclohexane, bis (4-aminocyclohexyl) methane, 2,2-bis (4-aminocyclohexyl) propane, bis (aminomethyl) decahydronaphthalene, bis (aminomethyl) ) Alicyclic diamine compounds such as tricyclodecane. Further examples include diamine compounds having an aromatic ring such as m-xylylenediamine, p-xylylenediamine, bis (4-aminophenyl) ether, p-xylylenediamine, and bis (aminomethyl) naphthalene.

Examples of the carboxylic acid component include aliphatics such as succinic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, adipic acid, sebacic acid, undecanedioic acid, and dodecanedioic acid. Dicarboxylic acid compounds. Moreover, a phthalic acid compound, such as isophthalic acid, terephthalic acid, and phthalic acid, is mentioned. Further examples include 1,2-naphthalenedicarboxylic acid, 1,3-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 1,6-naphthalenedicarboxylic acid, Naphthalene dicarboxylic acid compounds such as 1,7-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, etc. .

It also includes nylons, and these diamine components and dicarboxylic acid components may be used alone or in combination.

The cellulose fibers may be natural fibers or synthetic fibers. Examples of the synthetic fibers include halogenated fibers such as cellulose acetate.

Examples of such mixed fibers include polyethylene / polyethylene terephthalate, polypropylene / polyethylene terephthalate, and the like.

In the present invention, among the fibers, polyethylene terephthalate, polypropylene, acrylic resin, nylon and cellulose fibers are more preferred. The acrylic resin (especially acrylic acid) is preferably one having repeating units obtained from its ester, methacrylic acid, or its ester.

The fiber length of the fiber, that is, the average fiber length of the entire fiber used in the present invention varies depending on the manufacturing method of the fiber, and is usually preferably 1 mm or more and 100 mm or less, more preferably 10 mm or more and 90 mm or less, and more preferably It is 20 mm or more and 60 mm or less.

The diameter of the first fiber 20 is preferably 10 μm or more and 30 μm or less, and more preferably 15 μm or more and 25 μm or less. On the other hand, the diameter of the second fiber 40 is preferably 0.1 μm or more and 9 μm or less, and more preferably 0.5 μm or more and 5 μm or less.

Fibers with different fiber diameters may be fibers of the same composition or fibers of different compositions. In the present invention, fibers of the same composition are preferred. In addition, in the fiber length, mutually different fibers may be different or the same. In the present invention, fibers having the same fiber length are preferred.

The basis weight of the fibers constituting the wiping sheet 10 is preferably 1 g / m ² or more and 100 g / m ² or less, more preferably 5 g / m ² or more and 50 g / m ² or less, and further It is preferably 10 g / m ² or more and 30 g / m ² or less. On the other hand, the surface opposite to the wiping surface is preferably 10 g / m ² or more and 50 g / m ² or less, more preferably 15 g / m ² or more and 30 g / m ² or less, and more preferably It is 20 g / m ² or more and 25 g / m ² or less.

In relation to the weight per unit area of the fibers constituting the wiping sheet 10, the thickness T of the wiping sheet 10 under a load of 40 Pa is preferably 1 mm or more, further preferably 1.2 mm or more, and more preferably 1.5 mm or more . Also, under the same load, it is preferably 5 mm or less, more preferably 4 mm or less, and even more preferably 3 mm or less. The thickness T of the wiping sheet 10 is preferably 0.8 mm or more and 3 mm or less under a load of 370 Pa, more preferably 0.9 mm or more and 2.8 mm or less, and more preferably 1 mm or more and 2.5 mm or less. By setting the thickness T of the wiping sheet 10 within this range, the wiping sheet 10 becomes sufficiently rigid and strong, and the operability during wiping becomes good.

In the present invention, it is particularly preferable that fibers having different fiber diameters are entangled without being thermally fused with each other. In this way, the space between the fibers is increased compared to the case of thermal fusion. As a result, when the wiping liquid is carried on the wiping sheet 10, the load of the wiping liquid increases.

The wet wipe sheet 10 wipes the target surface once with one wipe, and the amount of the wiping liquid released from the wipe surface to the target surface is preferably 0.5 g / 畳 or more, more preferably 0.7 g / 畳 or more, It is more preferably 1.0 g / 畳 or more. The upper limit of the released amount is actually 8 g / 畳 or less, preferably 7 g / 畳 or less, and further preferably 6 g / 畳 or less. If the amount of release is too small, it will be impossible to wipe it sufficiently, and if it is too much, it will become easy for the wiping liquid to remain on the wiping surface. Here, the sacrificial system is 1820 mm × 910 mm, and the area is 1.6552 m ² .

The measurement conditions of the release behavior are a wiping load (load W) of 0.16 kN / m ² and a wiping speed (speed V) of 1 m / s. When the wiping sheet of the present invention is loaded with a wiping liquid, the amount of release per one when measured under such measurement conditions is in the above range.

The maximum liquid carrying amount that the wiping liquid can carry on the wiping sheet 10, that is, the initial liquid carrying amount, is described in the example that explains the size of one wiping sheet 10 below. When it is set to 285 mm x 205 mm, It is preferably 1 g / piece or more, more preferably 10 g / piece or more, and even more preferably 12 g / piece or more. The upper limit of the initial liquid carrying amount is actually 40 g / piece or less, preferably 30 g / piece or less, and further preferably 20 g / piece or less.

In this way, it becomes possible to achieve a liquid release amount of 1 g / 畳 or more per wiping of the target, and it can be continued for 6 第 or more.

The wiping liquid for wiping the sheet 10 is usually the same as a user in a wet wiping sheet. That is, the wiping liquid may be only water or an aqueous solution containing a surfactant, and preferably an aqueous solution containing a surfactant.

The surfactant may be any of a nonionic surfactant, an amphoteric surfactant, a cationic surfactant, or an anionic surfactant. For example, an anionic surfactant such as alkylbenzenesulfonic acid, or a nonionic surfactant such as polyoxyethylene alkyl ether can be used.

Wipes can also contain additives. Examples of the additives include polymers of acrylic acid, methacrylic acid, or maleic acid, or salts thereof, and copolymers of maleic acid and other vinyl-based monomers, or salts thereof, for the purpose of improving the rinse effect. In addition, water-soluble organic solvents such as bactericides, fragrances, fragrances, deodorants, abrasive particles, pH adjusters, alcohols, and the like can be mentioned.

The content of the surfactant and the additives as described above is usually in a range used in a wet wipe sheet.

Next, a preferred manufacturing method of the wiping sheet 10 shown in FIG. 1 will be described with reference to FIGS. 2 to 8. FIG. 2 shows a manufacturing apparatus 1 which is preferably used for manufacturing the wiping sheet 10. The manufacturing apparatus 1 includes a mesh forming portion 2, an entanglement portion 3, an electrospinning portion 4, and a convex portion forming portion 5.

The net forming portion 2 is a net forming the first fiber 20. The web forming unit 2 includes a card 21 for forming a web using the first fibers 20 as a raw material of the wiping sheet 10.

The entanglement part 3 is a person who entangles the net | network of the 1st fiber 20 by water flow. The entanglement portion 3 includes a first water flow nozzle 31 that blows a water flow to the web of the first fiber 20, and a first support belt 32 including an endless belt. The first water flow nozzle 31 is located above the mesh of the first fiber 20 and the first support belt 32, and can blow high-pressure water flow across the width direction of the mesh of the first fiber 20. The first support belt 32 is disposed to face the first water flow nozzle 31, and has a perforated structure (not shown) in a pattern such as a grid to allow the blown water to pass through. The entangled body of the first fiber 20 that is entangled by blowing a water stream from the first water flow nozzle 31 is conveyed to the electrostatic spinning unit 4 through the first support belt 32.

The electrospinning section 4 is a method in which a second fiber 40 containing nanofibers is generated by an electrospinning method, and the second fiber 40 is stacked on one face of the first fiber 20 intersecting with the water flow nozzle 31 of the intersecting section 3. . The electrospinning section 4 includes a jetting section 41 that jets the raw material liquid of the second fiber 40 and performs electrospinning, and a capture electrode 42 that captures the jetted raw material liquid as the second fiber 40. The ejection unit 41 includes a supply unit for the raw material liquid of the second fiber 40, an electrode, a voltage application unit, and the like (not shown). A positive voltage or a negative voltage is applied to the injection portion 41. The capture electrode 42 is disposed to face the ejection portion 41. The capture electrode 42 includes a conductive member and is grounded.

When a voltage is applied to the ejection section 41, the raw material liquid of the second fiber 40 is electrostatically charged during the period until it is ejected from the ejection section 41, and ejected in a charged state. The raw material liquid sprayed in a charged state generates self-repulsion of the raw material liquid by the action of an electric field, and generates the second fiber 40 as a nano-size fine fiber (nano fiber). The generated second fibers 40 are randomly deposited on one surface of the entanglement of the first fibers 20 traveling near the capture electrode 42 to form a fiber assembly. In this electrospinning step, a laminated body 50 including a fiber assembly of the first fibers 20 and the second fibers 40 is formed. The obtained laminated body 50 is conveyed to the convex part formation part 5.

As the raw material liquid of the second fiber 40 in the electrostatic spinning method, a liquid obtained by dissolving or dispersing a polymer compound constituting the second fiber 40 in a solvent or a melt liquid obtained by melting a polymer compound can be used. The method using a liquid obtained by dissolving or dispersing a polymer compound in a solvent may be referred to as a solution type electrospinning method, and the method using a molten solution obtained by melting a polymer compound may be referred to as a melt type electrostatic spinning law. In the present invention, any electrostatic spinning method can be used.

At the convex portion forming portion 5, a water stream is blown to the laminated body 50 of the fiber aggregate of the first fiber 20 and the fiber aggregate of the second fiber 40, and the first fiber and the second fiber are entangled to form a convex portion. The convex portion forming portion 5 includes a second water flow nozzle 51 that blows water to the laminated body 50 from the first fiber 20 side, a convex portion forming member 52 that forms a convex portion on the second fiber 40 side by the water flow, and is provided on the convex portion to form A second support belt 53 below the member 52 and a transport belt 54 that transports the laminated body 50 on which the convex portions are formed to a downstream manufacturing step.

As shown in FIG. 2, the second water flow nozzle 51 is located on the first fiber 20 side of the laminated body 50 and can blow the water flow across the entire width direction of the laminated body 50. The convex part forming member 52 is located below the laminated body 50 and is arranged to face the fiber assembly of the second fiber. As shown in FIG. 3, a plurality of circular opening portions 52a are regularly formed in the convex portion forming member 52 throughout the entire area. The convex portion forming member 52 is not particularly limited as long as it has an opening portion, and perforated metal, plastic mesh, or the like can be used. The shape of the opening portion 52a is not particularly limited, and may be an ellipse, a polygon such as a triangle, a quadrangle, or a pentagon in addition to the circle shown in FIG. 3. The convex portion forming member 52 may be integrated with the second support belt 53 by a method such as sewing or bonding.

As shown in FIGS. 2 and 4, the water flow blown from the second water flow nozzle 51 toward the surface 50X of the first fiber 20 side causes the surface 50Y of the second fiber 40 side of the laminated body 50 to contact the upper surface of the protrusion forming member 52. Pressed tightly. At the same time, the fiber assembly of the first fiber 20 and the second fiber 40 located in the opening portion 52a is caused to protrude in the opening portion 52a to form a plurality of convex portions 50A. At this time, the classification of the first fiber 20 and the second fiber 40 occurs, and the existence ratio of the first fiber 20 in the top portion 50T of the convex portion 50A to the top portion 50T of the entire fiber constituting the convex portion 50A becomes higher than that of the first fiber 20. The presence ratio of 2 fibers 40. At the same time, the presence ratio of the second fiber 40 in the foot portion 50B of the convex portion 50A with respect to the entire foot portion 50B of the fiber constituting the convex portion 50A becomes higher than the existence ratio of the first fiber 20. Through these steps, a laminated body 50 having a plurality of convex portions 50A can be obtained.

As shown in FIG. 5, the width L of the opening portion 52 a of the convex portion forming member 52 is preferably 400 μm or more and 10 mm. By having the width L, a convex portion 50A having a good appearance and reducing resistance during wiping can be formed in the laminated body 50.

As shown in FIG. 5, the thickness T of the protrusion forming member 52 is preferably 800 μm or more and 3 mm or less, and more preferably 900 μm or more and 2 mm or less. By having a thickness in this range, a good convex portion 50A can be formed in the laminated body 50.

As another embodiment of the convex portion forming portion 5 (hereinafter referred to as the second embodiment), as shown in FIGS. 6 and 7, in addition to the convex portion forming member 52, a second convex portion forming member 520 may also be used. The laminated body 50 has two types of convex portions 50A and second convex portions 520A (hereinafter, in the second embodiment, the convex portions 50A are also referred to as first convex portions 50A). In the second embodiment, as shown in FIG. 6, the second convex portion forming member 520 is disposed so as to overlap the upper portion of the convex portion forming member 52. The second convex portion forming member 520 is formed over the entire surface of the second convex portion forming member 520a. As shown in FIG. 8, the width La of the quadrangular opening portion 520 a becomes larger than the width L of the opening portion 52 a of the convex portion forming member 52. In this way, by using two types of convex-portion forming members 52 and 520 in an overlapping manner, the first convex portion is on the first surface 50Y side of the wiping sheet 10 (hereinafter, also referred to as the wiping sheet 10 'in the second embodiment). 50A may be formed in a manner of a plurality of and regularly arranged as a shape bulging from the top of the second convex portion 520A.

According to the second embodiment in which two types of convex portion forming members 52 and 520 are overlapped, the first surface 50Y side of the wiping sheet 10 'has a first convex portion 50A and a pattern including a macroscopic view larger than the first convex portion 50A. The second convex portion 520A (a diamond-shaped lattice pattern in the second embodiment), and the first convex portion 50A is located within the second convex portion 520A to form a two-level step difference. In this case, the presence ratio of the first fiber 20 in the top of the first convex portion 50A with respect to the entire fiber constituting the first convex portion 50A becomes higher than the existence ratio of the second fiber 40, and The foot ratio of the first convex portion 50A with respect to the foot portion of the entire fiber constituting the first convex portion 50A is higher than the existence ratio of the first fiber 20.

In the second embodiment in which two types of projection forming members 52 and 520 are overlapped, as shown in FIG. 7, the layered body 50 is formed by a water flow blown from the second water flow nozzle 51 toward the surface 50X of the first fiber 20 side. The surface 50Y on the second fiber 40 side is pressed against the second protrusion forming member 520 so as to be in close contact with each other. At this time, the first fibers 20 and the second fibers 40 enter the opening portions 520a, and a plurality of second convex portions 520A having a shape corresponding to the shape of the opening portions of the second convex portion forming member 520 are regularly formed. Furthermore, by the water flow blown from the second water flow nozzle 51, the second convex portion 520A is pressed against the surface 50Y of the second fiber 40 side and the convex portion forming member 52, and the first convex portion 50A is mostly and regularly The arrangement is formed on the top of the second convex portion 520A. In this way, the first convex portion 50A is raised from the top of one second convex portion 520A to form a plurality, and thereby the first convex portion 50A and the second convex portion 520A have a shape having a step difference of two levels. According to this step, as in the embodiment where the convex portion forming member 52 is used alone, a laminated body 50 in which a plurality of convex portions 50A are formed can also be obtained.

The wiping sheet 10 'according to the second embodiment obtained by the above steps protrudes from the surface (second surface) 50X of the first fiber 20 side toward the 50Y side of the second fiber side surface (first surface) to form a first protrusion. Part 50A and the second convex part 520A. The first convex portion 50A and the second convex portion 520A have shapes that are raised from the flat surface of the first surface 50Y. As described above, the first convex portion 50A is located inside the second convex portion 520A and has a shape that is raised from the top of the second convex portion 520A. By having these shapes, when viewed from the flat surface of the first surface 50Y, a convex portion having a step difference of two levels is formed. The second surface 50X can be flattened over the entire area by the manufacturing method of the wiping sheet 10 'in the second embodiment, and the areas corresponding to the first convex portion 50A and the second convex portion 520A can also be recessed.

As shown in FIG. 8, the width La of the opening portion 520 a of the second convex portion forming member 520 is preferably 400 μm or more and 10 mm or less, and more preferably 420 μm or more and 8 mm or less. By having the width La, the second convex portion 520A having a good appearance and reducing the resistance during wiping can be formed in the laminated body 50.

As shown in FIG. 8, the thickness T of the second convex portion forming member 520 is preferably 600 μm or more and 4 mm or less, and more preferably 700 μm or more and 3 mm or less. With the thickness within this range, the second convex portion 520A having a good appearance and reducing the resistance during wiping can be formed in the laminated body 50.

If it returns to FIG. 2 again, finally, the laminated body 50 of the convex part 50A will be formed by the convex part formation part 5, and it will be conveyed downstream from the convex part formation part 5 by the conveyance belt 54, and the target dry wipe sheet 10 ( Or wipe the sheet 10 '). In addition, after the laminated body 50 in which the convex portion 50A is formed by the convex portion forming portion 5 is conveyed downstream from the convex portion forming portion 5 by the conveyance belt 54, it can be further from the surface corresponding to the second surface of the wiping sheet 10. The wiping liquid is supplied on the side to carry it. By going through this step, the target wet wipe sheet 10 (or wipe sheet 10 ') can be obtained.

When the wet wiping sheet 10 (or the wiping sheet 10 ') is manufactured, the load of the wiping liquid is as described in the following example explaining the size of one wiping sheet, and when it is 285 mm x 205 mm It is preferably 6 g / piece or more, more preferably 8 g / piece or more, and even more preferably 10 g / piece or more. The upper limit of the content of the wiping liquid is preferably 40 g / piece or less, more preferably 30 g / piece or less, and even more preferably 20 g / piece or less. The method for supporting the wiping liquid may be spraying, coating, or dipping.

The wiping sheet 10 (or the wiping sheet 10 ') manufactured in this way can be used alone or attached to a cleaning appliance such as a wiper for use in buildings such as floors, walls, cabinets, Window glass, mirrors, doors, door handles and other building tools, small rugs, carpets, desks, dining tables and other furniture, kitchens, bathrooms, body wipes, or sanitary products, packaging, etc.

As mentioned above, although this invention was demonstrated based on the preferable embodiment, this invention is not limited to the said embodiment. For example, in FIG. 2, the number and the water pressure of the first and second water flow nozzles 31 and 51 may be the same or different.

In addition, the wiping sheet 10 (or the wiping sheet 10 ') of the above-mentioned embodiment is a type including two kinds of fibers including the first and second fibers, and may be a wiping sheet including three or more types of fibers instead.

Regarding the above embodiment, the present invention further discloses the following wiping sheet and a method for producing the same. <1> A wiping sheet comprising a fiber aggregate including at least a first fiber and a second fiber having a smaller diameter than the first fiber, and these fibers are entangled, and has a first surface serving as a wiping surface, And the second surface located on the opposite side of the first surface; and the existence ratio of the second fiber becomes higher than the second surface on the first surface; a plurality of convex portions are formed on the first surface side; The presence ratio of the first fiber in the top of the entire fiber of the convex portion becomes higher than the existence ratio of the second fiber; the existence ratio of the second fiber in the foot portion of the entire fiber constituting the convex portion becomes higher. Existing ratio to the first fiber.

<2> The wiping sheet according to the above <1>, in which the first fibers and the second fibers are entangled with each other without being thermally fused with each other. <3> The wiping sheet according to the above <1> or <2>, in which the area ratio of the second fiber in the first surface is preferably 40% or more and 99% or less, more preferably 45% or more and 95% or less % Or less, more preferably 50% or more and 90% or less, and the area ratio of the second fiber in the second surface is preferably 0% or more and 55% or less. <4> The wiping sheet according to any one of the items <1> to <3>, in which a plurality of the convex portions are regularly arranged. <5> The wiping sheet according to any one of <1> to <4>, wherein a region corresponding to the convex portion on the second surface side is recessed from the flat surface on the second surface toward the first surface to form a concave portion. <6> The wiping sheet according to any one of <1> to <4>, in which the entire area of the second surface is a flat surface.

<7> The wiping sheet according to any one of the above <1> to <6>, wherein the convex portion is a solid filled with fibers. <8> The wiping sheet according to any one of the above <1> to <6>, wherein the convex portion is a solid body whose interior is filled with the first fiber and / or the second fiber. <9> The wiping sheet according to any one of the above <1> to <8>, wherein the convex portions are regularly arranged on the first surface side of the wiping sheet. <10> The wiping sheet according to any one of the above <1> to <9>, wherein the convex portions are regularly arranged along the longitudinal direction of the wiping sheet and / or along the width direction. <11> The wiping sheet according to any one of <1> to <10>, wherein the convex portion has a width of 400 μm or more and 10 mm or less, and a height of 110 μm or more and 25 mm or less.

<12> The wiping sheet according to any one of the items <1> to <11>, wherein the width of the convex portion is further preferably 800 μm or more, more preferably 900 μm or more, and the width W is further preferably 8 mm. It is more preferably 5 mm or less. <13> The wiping sheet according to any one of the above <1> to <12>, which has a convex portion on the first surface side and a second convex portion including a macroscopic pattern larger than the convex portion, and The convex portion is located in the second convex portion to form a two-level step difference; at the top of the convex portion, the existence ratio of the first fiber to the top of the entire fiber constituting the convex portion becomes higher than that of the second fiber. The presence ratio of the fibers is higher than the presence ratio of the first fiber in the foot portion of the convex portion with respect to the second fiber in the foot portion of the entire fiber constituting the convex portion. <14> The wiping sheet as described in said <13> which has the said convex part on the top of the 2nd convex part larger than the said convex part. <15> The wiping sheet according to the above <13>, wherein a plurality of the convex portions are formed on the top of the second convex portion.

<16> The wiping sheet according to any one of the above <1> to <15>, wherein the friction between the object to be wiped and the wiping sheet is preferably applied to a wiping sheet having a size of 10 cm × 25 cm The resistance when wiping with a pressure of 55 N / m ² is 10 N or less, more preferably 5 N or less, and even more preferably 4 N or less. <17> The wiping sheet according to any one of the above <1> to <16>, wherein the existence ratio of the first fiber and the second fiber in the top of the convex portion is relative to the entire fiber constituting the convex portion, and the The second fiber is more than three times the first fiber. <18> The wiping sheet according to any one of the above <1> to <17>, in which the existence ratio of the first fiber and the second fiber in the foot portion of the convex portion is relative to the entire fiber constituting the convex portion. The second fiber is twice or more as large as the first fiber. <19> The wiping sheet according to any one of <1> to <18>, in which the first fiber and the second fiber are polyester, polyamide, polyolefin, cellulose fiber, or various metals and glass And mineral-based fibers, preferably polyester, polyamide, polyolefin, and cellulose fibers. <20> The wiping sheet as described in any one of <1> to <19>, wherein the first fiber and the second fiber are preferably fibers of the same composition.

<21> The wiping sheet according to any one of the above <1> to <20>, wherein the diameter of the first fiber is preferably 10 μm or more and 30 μm or less, and more preferably 15 μm or more and 25 μm or less. <22> The wiping sheet according to any one of the above <1> to <21>, wherein the diameter of the second fiber is preferably 0.1 μm or more and 9 μm or less, and more preferably 0.5 μm or more and 5 μm or less. <23> The wiping sheet according to any one of the above <1> to <22>, wherein the wiping liquid is carried on at least the fiber assembly on the second surface side. <24> The wiping sheet as described in said <23> which has the release layer of the said wiping liquid, and the liquid holding layer which carries the said wiping liquid, This release layer contains a 1st surface.

<25> The wiping sheet according to any one of the above <1> to <24>, in which when an imaginary circle with a diameter of 20 mm is drawn at an arbitrary position on the first surface, the above-mentioned convex portion existing in the imaginary circle The number is 10 or more and 60 or less. <26> The wiping sheet according to any one of the above <1> to <25>, wherein the weight per unit area of the fibers constituting the wiping sheet is 1 g / m ² or more and 100 g / m ^{2 on} the wiping surface side. the following. <27> The wiping sheet according to any one of the above <1> to <26>, wherein the thickness of the wiping sheet is 1 mm or more and 5 mm or less under a load of 40 Pa.

<28> A method for manufacturing a wiping sheet, which is the method for manufacturing a wiping sheet according to any one of the above <1> to <27>. The first fiber is a fiber assembly and is thinner than the first fiber. The laminated body of the fiber assembly of the second fiber of the diameter is arranged from the fiber assembly of the first fiber in a state where the fiber assembly of the second fiber and the projection forming member having a plurality of openings face each other. A water stream is blown on the other side to entangle the first fiber and the second fiber, and the fiber assembly located in the opening portion is caused to protrude in the opening portion. <29> The manufacturing method of the wiping sheet as described in said <28> which forms the fiber assembly of a 2nd fiber by a melt | dissolution electrospinning method. Examples

Hereinafter, the present invention will be described in more detail through examples. However, the scope of the present invention is not limited to this embodiment.

[Embodiment 1] Using the manufacturing apparatus 1 and the protrusion forming member 52 shown in Figs. 2 to 5, a wiping sheet 10 having a structure shown in Fig. 1 was produced. As the first fiber 20, a blend including PET: acrylic acid: 嫘 萦 = 7: 1.5: 1.5 and an average diameter of 11.4 μm in a mass ratio was used. As the second fiber 40, polypropylene having an average diameter of 1 μm obtained by an electrospinning method was used. The basis weight of the first fiber 20 is 60 g / m ² , and the basis weight of the second fiber 40 is 5 g / m ² . The wiping sheet 10 is rectangular and has a size of 285 mm × 205 mm and a thickness T of 1.6 mm. The height H of the convex portion 50A on the first surface 50Y side of the wiping sheet 10 is 0.7 mm, and the width W is 2 mm. There are 34 convex portions 50A arranged on an imaginary circle with a diameter of 20 mm. The area ratio of the second fiber 40 in the first surface 50Y is 90%, and the area ratio of the second fiber 40 in the second surface 50X is 5%. The existence ratio of the first fiber 20 in the top portion 50T of the entire fiber constituting the convex portion 50A is doubled on an area basis with respect to the second fiber 40 (67% in terms of area ratio) and relative to the convex portion. The existence ratio of the second fiber 40 in the mountain foot portion 50B of the fiber of 50A as a whole is 1.1 times as large as the area of the first fiber 20 (52% as the area ratio). The wiping sheet 10 of Example 1 is a wet wiping sheet carrying a wiping liquid. The wiping liquid is carried on at least the fiber assembly on the second surface side. The load of the wiping solution is 20 g / piece. As the wiping liquid, a 0.01% by mass aqueous solution of a surfactant (EMULGEN108, manufactured by Kao Corporation) was used.

[Example 2] A wiping sheet was produced in the same manner as in Example 1 except that the wiping liquid was not supported on the wiping sheet of Example 1. That is, the wiping sheet of Example 2 is a dry type.

[Comparative Example 1] As a wet wipe sheet, a Scotch · Brite (registered trademark) floor wet sheet manufactured by 3M Co. was used. The wet wiping sheet is a fiber assembly containing fine-diameter fibers and large-diameter fibers, but the convex portion of the present invention is not formed on the wiping surface.

[Comparative Example 2] As a dry wiping sheet, a Scotch · Brite (registered trademark) floor wet sheet manufactured by 3M Co. was dried for 24 hours under an environment of a temperature of 20 ° C and a relative humidity of 65%. The wiping sheet is a fiber assembly containing fine-diameter fibers and large-diameter fibers, but the convex portion of the present invention is not formed on the wiping surface.

[Comparative Example 3] As the dry wiping sheet, an ultrafine adsorption dry sheet manufactured by Yamazaki Industries was used. The wiping sheet is a fiber assembly containing fine-diameter fibers and large-diameter fibers, but the convex portion of the present invention is not formed on the wiping surface.

[Evaluation] The wipe sheet of each example and comparative example was subjected to a pressure of 55 N / m ² , and a floor (Conbit new advance101, manufactured by WOODONE) was set as the surface to be wiped, and wiped in an area of 1.8 m ² . The resistance at this time was measured by the above method. The results are shown in FIGS. 9 and 10.

The resistances in Example 1 and Comparative Example 1 which are wet wipe sheets were compared. As a result, as shown in FIG. 9, the resistance in Example 1 was 2.7 N. On the other hand, the resistance of Comparative Example 1 was 15.7 N. From these results, it is understood that the frictional resistance during wiping of the wet wiping sheet 10 of Example 1 is small, and the operability is high.

The resistances in Example 2 and Comparative Examples 2 and 3, which are dry wipe sheets, were compared. As a result, as shown in FIG. 10, the resistance in Example 2 was 1.8 N. On the other hand, the resistance of Comparative Example 2 was 2.2 N, and the resistance of Comparative Example 3 was 4.1 N. From these results, it can be seen that the dry-type wipe sheet 10 of Example 2 is the same as the wet-type wipe sheet 10 of Example 1, and has less frictional resistance during wiping and high operability.

In particular, as is clear from the comparison between Example 1 and Comparative Example 1, and Example 2 and Comparative Example 2, it can be seen that when the wiping sheet of the present invention is used in a wet manner, the reduction in frictional resistance becomes significant. [Industrial availability]

According to the present invention, there is provided a wiping sheet which reduces frictional resistance during wiping and improves operability during wiping, and a method for manufacturing the same.

1‧‧‧ manufacturing equipment

2‧‧‧Net formation department

3‧‧‧Communication Department

4‧‧‧ Electrospinning Department

5‧‧‧ convex forming portion

10‧‧‧ wipe sheet

20‧‧‧ the first fiber

21‧‧‧carding machine

31‧‧‧The first water jet nozzle

32‧‧‧The first support zone

40‧‧‧ 2nd fiber

41‧‧‧jetting department

42‧‧‧ Capture electrode

50‧‧‧ laminated body

50A‧‧‧ convex

50B‧‧‧ Mountain Foot

50C‧‧‧Concave

50T‧‧‧ the top of the protrusion

50X‧‧‧ 2nd surface (surface on the 20th side of the first fiber)

50X'‧‧‧ 2nd flat surface

50Y‧‧‧The first side (wiping side)

50Y'‧‧‧ flat surface of 1st surface

51‧‧‧Second water jet nozzle

52‧‧‧ convex forming member

52a‧‧‧opening

53‧‧‧ 2nd support band

54‧‧‧ transport belt

520‧‧‧ 2nd projection forming member

520A‧‧‧ 2nd convex part

520a‧‧‧opening

H‧‧‧ height 50A

L‧‧‧ opening width 52a

La‧‧‧ width of opening 520a

T‧‧‧thickness

W‧‧‧ 50A width of protrusion

FIG. 1 is an enlarged view of a main portion of a convex portion in a wiping sheet of the present invention. Fig. 2 is a schematic view of a manufacturing apparatus for a wiping sheet of the present invention. FIG. 3 is a plan view of an embodiment of a protrusion forming member used in the present invention. Fig. 4 is an enlarged view of a main part showing a step of manufacturing the wiping sheet of the present invention. Fig. 5 is a sectional view taken along the line A-A in Fig. 3. FIG. 6 is a plan view of another embodiment of a convex-forming member used in the present invention. FIG. 7 is an enlarged view of an essential part showing another step of manufacturing the wiping sheet of the present invention (equivalent to the view of FIG. 4). Fig. 8 is a sectional view taken along the line B-B in Fig. 6. FIG. 9 is a graph of frictional resistance values of the wet wiping sheet in Example 1 and Comparative Example 1. FIG. FIG. 10 is a graph showing the frictional resistance values of the dry wipe sheet in Example 2 and Comparative Examples 2 and 3. FIG.

Claims (29)

A wiping sheet is provided with at least a first fiber, a second fiber having a smaller diameter than the first fiber, and a fiber aggregate formed by intersecting these fibers, the first surface serving as a wiping surface, and The second surface on the opposite side of the first surface; and the existence ratio of the second fiber becomes higher than the second surface on the first surface; a plurality of convex portions are formed on the first surface side; The existence ratio of the first fiber in the top of the entire fiber becomes higher than the existence ratio of the second fiber; the existence ratio of the second fiber in the foot portion of the entire fiber constituting the convex portion becomes higher than the first fiber. The presence ratio of fibers. For example, the wiping sheet of claim 1, wherein the first fiber and the second fiber are entangled without being thermally fused with each other. For example, the wipe sheet of claim 1, wherein the area ratio of the second fiber in the first surface is 40% to 99%; and the area ratio of the second fiber in the second surface is 0% or more And less than 55%. As in the wiping sheet of claim 1, a plurality of the convex portions are regularly arranged. As in the wiping sheet of claim 1, wherein the area corresponding to the convex portion on the second surface side is recessed from the flat surface of the second surface toward the first surface to form a concave portion. If the wiping sheet of item 1 is requested, the entire area of the second surface becomes a flat surface. As in the wiping sheet of claim 1, wherein the convex portion is a solid body whose interior is filled with fibers. If the wiping sheet of item 1 is requested, the convex part is a solid body whose interior is filled with the first fiber and / or the second fiber. The wiping sheet according to claim 1, wherein the convex portions are regularly arranged on the first surface side of the wiping sheet. The wiping sheet according to claim 1, wherein the convex portions are regularly arranged along the longitudinal direction and / or the width direction of the wiping sheet. As for the wiping sheet of claim 1, wherein the above-mentioned convex portion has a width of 400 μm or more and 10 mm or less, and a height of 110 μm or more and 25 mm or less. As for the wiping sheet according to claim 1, wherein the convex portion has a width of 800 μm or more and 8 mm or less. For example, the wiping sheet of claim 1 has the above-mentioned convex portion on the first surface side, and a second convex portion including a macroscopic pattern larger than the above-mentioned convex portion, and the convex portion is located in the second convex portion to form two The difference in level; at the top of the convex portion, the presence ratio of the first fiber to the top of the entire fiber constituting the convex portion becomes higher than the existence ratio of the second fiber, and at the foot of the convex portion The presence ratio of the second fiber in the foot portion of the entire fiber constituting the convex portion becomes higher than the presence ratio of the first fiber. According to the wiping sheet of claim 13, the convex portion is formed on the top of the second convex portion larger than the convex portion. According to the wiping sheet of claim 13, a plurality of the protrusions are formed on the top of the second protrusions. For example, the wiping sheet of claim 1 has a resistance of 10 N or less when a pressure of 55 N / m ² is applied to a wiping sheet having a size of 10 cm × 25 cm. For example, if the wiping sheet of claim 1 is used, the existence ratio of the first fiber and the second fiber in the top portion of the convex portion is relative to the entire fiber constituting the convex portion, and the second fiber is the first fiber based on the number of fibers. 3 times or more. For example, if the wiping sheet of claim 1 is used, the existence ratio of the first fiber and the second fiber in the foot portion of the convex portion is relative to the entire fiber constituting the convex portion, and the second fiber is the first fiber based on the number of fibers. 2 times more. For example, the wiping sheet of claim 1, wherein the first fiber and the second fiber are independent, and are polyester, polyamide, polyolefin, cellulose fibers, and fibers using various metals, glass, or minerals as raw materials. If the wiping sheet of item 1 is requested, the first fiber and the second fiber are fibers of the same composition. For example, the wiping sheet of claim 1, wherein the diameter of the first fiber is 10 μm or more and 30 μm or less. As in the wiping sheet of claim 1, wherein the diameter of the second fiber is 0.1 μm or more and 9 μm or less. The wiping sheet according to claim 1, wherein the wiping liquid is carried at least on the fiber assembly on the second surface side. For example, the wiping sheet of claim 23 includes the release layer of the wiping liquid and a liquid retaining layer supporting the wiping liquid, and the releasing layer includes a first surface. For example, if the wiping sheet of claim 1 is to draw an imaginary circle with a diameter of 20 mm at an arbitrary position on the first surface, the number of the above-mentioned convex portions existing in the imaginary circle is 10 or more and 60 or less. The wiping sheet according to claim 1, wherein the unit area weight of the fibers constituting the wiping sheet is 1 g / m ² or more and 100 g / m ² or less on the wiping surface side. As in the wiping sheet of claim 1, wherein the thickness of the wiping sheet is 1 mm or more and 5 mm or less under a load of 40 Pa. A method for manufacturing a wiping sheet, which is the method for manufacturing a wiping sheet according to claim 1; a laminated body comprising a fiber assembly of a first fiber and a fiber assembly of a second fiber having a smaller diameter than the first fiber; In a state in which the fiber assembly of the second fiber and the convex portion forming member having a plurality of openings face each other, a water flow is blown from the side of the fiber assembly of the first fiber, so that the first fiber and the second fiber The fibers are entangled, and the fiber assembly located in the opening portion is caused to protrude in the opening portion. The method for producing a wiping sheet according to claim 28, wherein the fiber assembly of the second fibers is formed by a melt electrospinning method.