TWI780197B - Wiping sheet and method of making the same - Google Patents

Abstract

The wiping sheet (10) of the present invention has a fiber aggregate formed by intertwining first fibers (20) and second fibers (40) having a smaller diameter than the first fiber (20), has a first surface (50Y) as a wiping surface, and The second surface (50X) on the opposite side. The abundance ratio of the second fiber (40) becomes higher on the first surface than on the second surface. A plurality of protrusions (50A) are formed on the side of the first surface (50Y), and at the top (50T) of the protrusions (50A), the first The abundance ratio of the fibers (20) becomes higher than the abundance ratio of the second fibers (40). In the mountain foot (50B) of the convex portion (50A), the abundance ratio of the second fiber (40) in the mountain foot (50B) of the entire fiber constituting the convex portion (50A) becomes higher than that of the first fiber (20B). ) of the existence ratio.

Description

Wiping sheet and manufacturing method thereof

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

Various attempts have been made to form a concave-convex structure on the surface of the nonwoven fabric to improve the function of the nonwoven fabric. For example, Patent Document 1 describes a nonwoven fabric, which is composed of at least one polymer fiber of nanofibers and microfibers by electrospinning, and has a concave-convex micro-pattern at a specific position on the plane. According to the same document, the non-woven fabric can achieve functional enhancement by using the shape specificity obtained from the concave-convex micro-pattern structure, improve cell affinity or material structure, and can also adjust biological functionality.

Patent Document 2 describes a nonwoven fabric comprising ultrafine fibers of 1 dtex or less and having unevenness on the surface. The surface of the non-woven fabric includes fiber bundles in which a plurality of fibers are intertwined with each other, and depressions in the vicinity thereof. Furthermore, the number of ultrafine fibers occupying the fiber bundle becomes larger than the number of ultrafine fibers occupying the depressions. As described in the literature, the nonwoven fabric has excellent bulkiness, is soft, and has a soft touch when it comes into contact with an object.

[Prior Art Literature] [Patent Document]

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 at least the first fiber and The second fiber having a diameter smaller than the first fiber, and the fiber assembly formed by intertwining these fibers have a first surface serving as a wiping surface and a second surface on the opposite side of the first surface. The abundance ratio of the second fiber becomes higher on the first surface than on the second surface. A plurality of protrusions are formed on the first surface side. The abundance ratio of the first fiber is higher than the abundance ratio of the second fiber at the top of the entire fiber constituting the convex portion. The abundance ratio of the second fiber is higher than the abundance ratio of the first fiber in the mountain foot portion relative to the entire fiber constituting the convex portion.

In addition, the present invention provides a method of manufacturing a wiping sheet. As a preferred method of manufacturing the above-mentioned wiping sheet, the fiber aggregate of the first fiber and the fiber aggregate of the second fiber having a smaller diameter than the first fiber are combined. The laminate is arranged such that the fiber aggregate of the second fibers faces the protrusion forming member having a plurality of openings. In this state, water flow is blown from the side of the fiber assembly of the first fibers to intertwine the first fibers with the second fibers, and make the fiber assembly located in the opening protrude in the opening.

1: Manufacturing device

2: Net forming part

3: Communication department

4: Electrospinning department

5: Convex part forming part

10: Wipe the sheet

20: 1st fiber

21: Carding machine

31: No. 1 water nozzle

32: The first support belt

40: 2nd fiber

41: Injection department

42: capture electrode

50: laminated body

50A: convex part

50B: The foot of the convex part

50C: Concave

50T: Top of convex part

50X: 2nd face (the 20th side of the 1st fiber)

50X': the flat surface of the second surface

50Y: 1st side (wiping side)

50Y': the flat surface of the first surface

51: The second water flow nozzle

52: Convex part forming member

52a: Hole part

53: The second support belt

54: conveyor belt

520: Second protrusion forming member

520A: 2nd convex part

520a: opening part

H: the height of the convex part 50A

L: Width of opening 52a

La: Width of the opening 520a

T: Thickness

W: Width of convex portion 50A

Fig. 1 is an enlarged view of the main part of the convex part in the wiping sheet of the present invention.

Fig. 2 is a schematic diagram of a manufacturing device of the wiping sheet of the present invention.

Fig. 3 is a plan view of an embodiment of the protrusion forming member used in the present invention.

Fig. 4 is an enlarged view of essential parts showing the steps of manufacturing the wiping sheet of the present invention.

Fig. 5 is a sectional view of line A-A in Fig. 3 .

Fig. 6 is a plan view of another embodiment of the protrusion forming member used in the present invention.

Fig. 7 is an enlarged view of an essential part (corresponding to Fig. 4 ) showing another step of manufacturing the wiping sheet of the present invention.

Fig. 8 is a sectional view of line B-B in Fig. 6 .

FIG. 9 is a graph of frictional resistance values of wet wiping sheets in Example 1 and Comparative Example 1. FIG.

FIG. 10 is a graph of frictional resistance values of dry wiping sheets in Example 2 and Comparative Examples 2 and 3. FIG.

As articles for wiping hard surfaces such as floors or furniture, wiping sheets comprising non-woven fabrics are often used. The above-mentioned patent document 1 describes the technology of non-woven fabrics, but the non-woven fabrics described in the document are intended to be applied to medical devices such as regenerative medicine, and there is no mention of the functionality of the non-woven fabrics for the purpose of wiping or cleaning.

When using the non-woven fabric with a concave-convex structure described in Patent Document 2 as a cleaning product, because the non-woven fabric contains fine-diameter fibers, the frictional resistance between the non-woven fabric and the cleaning object becomes larger, and the operability of the non-woven fabric during cleaning is poor. situation.

Therefore, the present invention relates to a wiping sheet that reduces frictional resistance between the object to be wiped and improves operability when wiping.

Below, the wiping sheet of this invention is demonstrated based on the preferable embodiment. In the present invention, the so-called wiping includes the meaning of both cleaning and wiping, for example, it includes the cleaning of buildings such as floors, walls, ceilings and pillars, the cleaning of building tools or spare parts, the wiping of articles, and the cleaning of bodies and bodies. Cleaning of utensils, etc.

The wiping sheet of the present invention contains fiber aggregates. The fibers constituting the fiber assembly include at least first fibers and second fibers having a smaller diameter than the first fibers. The first fibers and the second fibers form the above-mentioned fiber aggregate by interlacing first fibers, second fibers, and first fibers and second fibers. A wiping liquid may also be carried on this fiber assembly. The wiping liquid and its loading method are described in detail below. In addition, in this specification, when simply referring to a "wiping sheet", it refers to a thing carrying a wiping liquid and a thing not carrying a wiping liquid according to the context.

The fiber assembly system used for wiping sheet 10 is based on the entanglement of the first and second fibers. The main body is a composite fiber aggregate. Here, the wiping surface of the wiping sheet 10 is also called a front 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 principal part of the longitudinal cross-section of one embodiment of the wiping sheet of this invention is enlarged and shown. As shown in this figure, the wiping sheet 10 is comprised including the 1st fiber 20 and the 2nd fiber 40. As shown in FIG. Moreover, the wiping sheet 10 has the 1st surface 50Y and the 2nd surface 50X located in the opposite side to the 1st surface 50Y. The first surface 50Y of the wiping sheet 10 is provided as a wiping surface at the time of use of the wiping sheet 10 . As shown in FIG. 1 , there is a fiber aggregate of second fibers 40 which are fibers having a smaller fiber diameter on the upper side of the figure, and this is a wiping surface. Therefore, the lower side in the figure is the opposite side of the wiping surface, the back side.

The wiping sheet 10 protrudes toward the 1st surface 50Y side from this 2nd surface 50X, and forms convex part 50A by this. 50 A of convex parts are formed over the surface direction of the wiping off sheet 10 plurally. 50 A of convex parts become the shape which raised the 1st surface 50Y of the wiping off sheet 10 from flat surface 50Y'. On the side of the second surface 50X, 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 manufacturing method of the wiping sheet 10, the whole area|region of the 2nd surface 50X can also become a flat surface. In addition, in this specification, the description about 1st surface 50Y (wiping surface) assumes that 50 A of convex parts are not included.

Each convex portion 50A is solid and filled with the first fiber 20 and/or the second fiber 40 . The shapes and sizes of the respective protrusions 50A may be the same or different. When the ease of manufacture of the wiping sheet 10 is considered, it is preferable that the shape and size of each convex part 50A are the same.

Each convex part 50A may be arrange|positioned regularly on the 1st surface 50Y side of the wiping off sheet 10, or may be arrange|positioned irregularly. When arrange|positioning each convex part 50A regularly on 1st surface 50Y, it can arrange|position regularly along the longitudinal direction of the wiping sheet 10, and/or along the width direction, for example. In either case where the protrusions 50A are regularly and irregularly arranged, by wiping A plurality of protrusions 50A are formed on the first surface 50Y side of the surface, and when the wiping operation of the wiping sheet 10 is carried out, the frictional force between the wiping object surface and the wiping sheet 10 can be effectively reduced, and it can be easily Perform a wipe operation.

As shown in FIG. 1 , when the wiping sheet 10 is viewed in its longitudinal section, the locations where the first fibers 20 and the second fibers 40 exist are segregated. In detail, the abundance ratio of the 2nd fiber 40 of the wiping sheet 10 becomes higher than the 2nd surface 50X which is the surface opposite to a wiping surface in 1st surface 50Y which is a wiping surface. By employing this structure, the wiping effect of the wiping sheet 10 can be improved in conjunction with the formation of the plurality of protrusions 50A on the first surface 50Y side.

As mentioned above, the existence ratio of the 2nd fiber 40 of the wiping sheet 10 becomes higher than the surface opposite to the wiping surface in the wiping surface. And, if focusing on the first surface 50Y as the wiping surface, the convex portion 50A formed on the first surface 50Y side is formed at the top 50T, and the first fiber 20 in the top 50T of the entire fiber constituting the convex portion 50A is The abundance ratio becomes higher than the abundance ratio of the second fiber 40 . On the other hand, in the foot portion 50B of the convex portion 50A, the abundance ratio of the second fibers 40 in the foot portion 50B relative to the entire fibers constituting the convex portion 50A is higher than the abundance ratio of the first fibers 20 . When the abundance ratio of the 1st and 2nd fiber 20,40 which comprises 50 A of convex parts becomes like this, it turned out unexpectedly that the frictional force between the surface to be wiped and the wiping sheet 10 can be effectively reduced.

The frictional force between the wiping object surface and the wiping sheet 10 is preferably to apply a pressure of 55N/m to the wiping sheet ¹⁰ of the size of 10cm * 25cm and the resistance when wiping the wiping object surface is below 10N, and then relatively Preferably it is 5N or less, more preferably 4N or less. The lower limit of the resistance is not particularly limited, and the lower the better, if the resistance is as low as about 0.8N, the wiping operation can be performed smoothly.

The measurement of the resistance at the time of wiping is specifically performed by the following method. A crocodile-shaped clamp was installed at the front end of the tension gauge (RX-20, manufactured by Aikoh Engineering Co., Ltd.). The head of a Quickle wiper (manufactured by Kao Co., Ltd.) equipped with a wiping sheet having a size of 285 mm×205 mm was attached to the jig. The maximum load recorded by the tension gauge when the head was scanned for 1 m at a speed of 1 cm/sec on the floor (Conbit new advance 101, manufactured by WOODONE Co.) was measured as resistance.

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

From the point of view of reducing the frictional force between the surface to be wiped and the wiping sheet 10 more effectively, the ratio of the first fibers 20 and the second fibers 40 in the top 50T of the convex portion 50A is preferably higher than that of the convex portion. In the entirety of the fibers in the portion 50A, the number of first fibers is more than three times that of the second fibers. From the same viewpoint, the abundance ratio of the first fibers 20 and the second fibers 40 in the mountain foot portion 50B of the convex portion 50A is preferably such that the number of second fibers relative to the entire fibers constituting the convex portion 50A is The number of fibers is more than twice that of the first fiber.

The frictional force between the surface to be wiped off 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 more preferably 900 μm or more. Also, the width W is preferably 10 mm or less, more preferably 8 mm or less, and more preferably 5 mm or less. The width W is preferably from 400 μm to 10 mm, more preferably from 800 μm to 8 mm, more preferably from 900 μm to 5 mm. As shown in FIG. 1, width W measures the position which started rising from the flat surface 50Y' convex part 50A of the 1st surface 50Y of the wiping sheet 10 as a starting point. When focusing on one convex portion 50A, when the measured width W of the convex portion 50A is different in any direction, the width W of the above-mentioned convex portion 50A means the widest width measured. Also, when focusing on a plurality of convex portions 50A, the measured widths of the respective convex portions 50A are different. In this case, the width W of the above-mentioned convex portion 50A refers to the arithmetic mean value of the widths of the respective convex portions 50A to be measured.

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 more preferably 900 μm or more. Also, the height H is preferably 25 mm or less, more preferably 20 mm or less, more preferably 18 mm or less. The height H is preferably from 110 μm to 25 mm, more preferably from 500 μm to 20 mm, more preferably from 900 μm to 18 mm. As shown in FIG. 1, height H is the distance from the flat surface 50Y' of the 1st surface 50Y of the wiping sheet 10 to the apex of the convex part 50A. When focusing on a plurality of protrusions 50A, when the heights of the protrusions 50A are different, the height of the protrusions 50A refers to the arithmetic mean of the heights of the protrusions 50A to be measured.

The formation density of the convex part 50A on the 1st surface 50Y side may also affect the frictional force between the surface to be wiped and the wiping sheet 10 . From the viewpoint of reducing friction more effectively, when an imaginary circle with a diameter of 20 mm is drawn at an arbitrary position on the first surface 50Y, the number of protrusions 50A existing within the imaginary circle is preferably 10 or more. Furthermore, it is more preferable that it is 15 or more, and it is more preferable that it is 20 or more. Also, the number of convex portions 50A is preferably 60 or less, more preferably 50 or less, and more preferably 40 or less. The number of convex parts 50A is preferably 10 or more and 60 or less, more 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 may be a dry type that does not carry a wiping liquid (hereinafter also referred to as a "dry type wiping sheet"), or may be a wet type that carries a wiping liquid. The form of the wiping liquid (hereinafter, this form is also referred to as "wet wiping 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 aggregate located on the second surface side. Furthermore, when the wiping liquid is carried on at least the fiber assembly on the side of the second surface, the fiber assembly on the opposite side of the wiping surface contains the wiping liquid, and also includes A state in which the fiber assembly on the side of the wiping surface contains the wiping liquid in the voids thereof. In addition, it is preferable that the amount of the wiping liquid to be carried is that the amount of the fiber aggregate on the opposite side of the wiping surface is relatively large.

Especially when the wiping sheet 10 of the present invention is made into a wet wiping sheet, in addition to forming a plurality of the above-mentioned convex portions 50A, the first fiber 20 and the first fiber 20 in the top 50T of the convex portion 50A and the mountain foot portion 50B 2 The existence ratio of the fibers 40, the width W or the 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 during wiping. This is advantageous in more obvious ways.

From the point of view of further improving the wiping effect of the wiping sheet 10 in combination with the formation of a plurality of protrusions 50A, and from the point of view of being able to carry a large amount of wiping liquid stably in the case of a wet wiping sheet 10, On the surface of the wiping sheet 10 that also includes voids, the area ratio of the second fiber on the wiping surface is preferably 40% to 99%, more preferably 45% to 95%, and still more preferably Above 50% and below 90%. On the other hand, the area ratio of the second fibers on the surface opposite to the wiping surface is preferably 0% or more and 55% or less. The area occupied by the second fibers on the wiped surface can be determined, for example, by measuring the area occupied by fibers with a smaller fiber diameter from an image or photograph taken of the wiped surface. Hereinafter, the area occupied by fibers can be obtained in the same manner as above. Therefore, the area ratio is a value obtained by dividing the area occupied by fibers by the area to be measured. In addition, when expressed in %, 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 voids. This gap is necessary for releasing 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 wiping sheet 10 is used, the amount of wiping liquid released for wiping the stains on the surface to be wiped can be suppressed to a necessary amount even when wiping vigorously. Also, by setting the area ratio occupied by the second fiber in the surface opposite to the wiping surface in the above-mentioned manner, as a result, the voids increase, and the wiping in the wet wiping sheet 10 The loading capacity of the swab increases. If the area ratio occupied by the second fibers on the wiping surface is too small, the wiping liquid will be released more than necessary. Therefore, the wipeable area becomes smaller.

In the wiping sheet 10, the area ratio occupied by the second fibers 40 is preferably reduced stepwise, curvedly, or in combination thereof toward the thickness direction on the opposite side of the wiping surface on a plane parallel to the wiping surface. In particular, by setting the thickness of the wiping sheet 10 to 50% to 100% from the surface opposite to the wiping surface, and setting the area ratio occupied by the second fibers 40 to 50% to 100% If the range is set as the wet wiping sheet 10, the loading capacity of the wiping liquid can be increased. Here, the ratio of the above-mentioned thickness in which the area ratio occupied by the second fiber 40 is in the range of 50% to 100% is preferably 1% to 90%, 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 mentioned above, when using it as the wet wiping sheet 10, the wiping liquid released for wiping off the stain|pollution of the wiping object surface of a necessary amount can be released. Furthermore, the thickness of the wiping sheet 10 is the distance T from the surface opposite to the wiping surface to the apex of the convex portion 50A as shown in FIG. 1 .

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

The wet wiping sheet 10 includes at least two layers of a liquid retention layer carrying a wiping liquid and a wiping liquid release layer, and the release layer includes a wiping surface. Especially in order to carry a large amount of wiping liquid, as mentioned above, from the surface opposite to the wiping surface, the thickness of the wiping sheet 10 is set to 50% or more and 100% or less, and the area ratio of the second fiber is set to 1% or more and 100% or less. Thereby, it can be used as a liquid retention layer carrying a large amount of wiping liquid. On the other hand, the release layer includes parts other than the liquid retaining layer of the wiping surface.

In the wiping sheet 10, it is preferable that the capillary pressure on the wiping side is higher than that of the wiping side the opposite side. Thereby, especially when it is used as the wet wiping sheet 10, the amount of wiping liquid released for wiping the stains on the surface to be wiped can be controlled to a necessary amount even when wiping vigorously. Therefore, when wiping large areas such as rugs, carpets, floors, etc., it is not necessary to replace the wiping sheet 10 with a new wiping sheet 10 in the middle of wiping, or the number of replacements can be reduced.

Here, it is known that the capillary pressure is based on the following relationship.

Pc=2kγ _L /r×cosθ

In the formula, Pc is the capillary pressure of the fiber assembly (N/m ² ), γ _L is the surface tension of the liquid (N/m), θ is the contact angle between the fiber and the liquid (rad), r is the fiber diameter (m) , k is the correction coefficient.

The Pc derived by the above formula uses the value of the summary statistic derived by the measurement of the fiber aggregate. In order to determine Pc, it is necessary to measure the surface tension of the liquid, the diameter of the fiber, the contact angle between the fiber and the liquid, and the correction coefficient. The surface tension is an average value obtained by measuring 10 times at 20°C and 65% R.H. using an automatic surface tensiometer based on the plate method such as DY-200 manufactured by Kyowa Interface Science Co., Ltd. The fiber diameter is taken as the average value obtained by observing 30 fibers at a magnification of 350 times, observing 5 locations at random, and measuring the diameter of 150 fibers by observing with a scanning electron microscope. The contact angle between fiber and liquid is identified by Fourier Transform Infrared Spectroscopy (FTIR) to identify the constituent fibers of the fiber assembly, and the contact angle on a resin plate with the same composition is measured. Specifically, using a fully automatic contact angle meter such as DMo-901 manufactured by Kyowa Interface Science Co., Ltd., the contact angle at 3 seconds after dropping 1 μL was measured at 5 positions on the plate, and the average value thereof was used. In addition, in the case where there are a plurality of fiber materials, the contact angle is measured in the same manner for each material, and the value obtained by weighting the average contact angle based on the surface area ratio of each fiber component is set as the value at the time of Pc calculation. is θ in the formula. The correction factor is for the determination of the Klemm water absorption specified in JIS P 8141, and the liquid is measured according to the water absorption height Water absorption weight, the water absorption weight is divided by the total amount of the capillary cross-section constituting the non-woven fabric, thereby deriving the capillary pressure Pc, and calculating the correction factor k based on the Pc measured in this way.

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 fibers constituting the wiping sheet 10 are at least two types of fibers having different fiber diameters. The fibers are independent, represented by polyester, polyamide, polyolefin, cellulose fibers, or fibers made of various metals, glass, and minerals. Among them, polyester, polyamide, polyolefin, and cellulose fibers are preferable.

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

Polyolefins are obtained from monomers having ethylenically unsaturated groups. Examples include: polyethylene, polypropylene, ethylene-propylene copolymer, polyvinyl acetate, ethylene-vinyl acetate copolymer, cyclic acetal of polyvinyl alcohol, acrylic resin (including acrylic resin and methacrylic resin) , PVC. The polyolefin is as described above, and may be a homopolymer or a copolymer.

Any polyamide may be used as long as the polyamide has a structure having an amide bond in the polymer main chain. For example, polycondensation nylon such as nylon 6, nylon 11, and nylon 12, co-condensation nylon such as nylon 66, nylon 610, nylon 612, nylon 6T, nylon 6I, nylon 9T, and nylon M5T are mentioned. Moreover, the polyamide obtained using the following diamine component and dicarboxylic acid component is mentioned.

Examples of diamine components include tetramethylenediamine, pentamethylenediamine, 2-methylpentamethylenediamine, hexamethylenediamine, heptamethylenediamine, and octamethylenediamine. , nonamethylenediamine, decamethylenediamine, dodecamethylenediamine, 2,2,4-trimethyl-hexamethylenediamine, Aliphatic diamine compounds such as 2,4,4-trimethylhexamethylenediamine. 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)decalin, bis(aminomethyl ) Alicyclic diamine compounds such as tricyclodecane. Furthermore, diamine compounds having an aromatic ring, such as m-xylylenediamine, p-xylylenediamine, bis(4-aminophenyl)ether, p-phenylenediamine, and bis(aminomethyl)naphthalene, are mentioned.

Examples of the carboxylic acid component include aliphatic acids 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, phthalic acid compounds, such as isophthalic acid, terephthalic acid, and phthalic acid, are mentioned. Further, 1,2-naphthalene dicarboxylic acid, 1,3-naphthalene dicarboxylic acid, 1,4-naphthalene dicarboxylic acid, 1,5-naphthalene dicarboxylic acid, 1,6-naphthalene dicarboxylic acid, 1,7-naphthalene dicarboxylic acid, 1,8-naphthalene dicarboxylic acid, 2,3-naphthalene dicarboxylic acid, 2,6-naphthalene dicarboxylic acid, 2,7-naphthalene dicarboxylic acid and other naphthalene dicarboxylic acid compounds .

Nylons are also included, and these diamine components and dicarboxylic acid components may be used alone or in combination.

The cellulose fiber may be a natural fiber or a synthetic fiber, and examples of the synthetic fiber include acylated fibers such as acetate of cellulose.

Moreover, these mixed fibers, for example, polyethylene/polyethylene terephthalate, polypropylene/polyethylene terephthalate, etc. are also mentioned.

In the present invention, among the above-mentioned fibers, polyethylene terephthalate, polypropylene, acrylic resin, nylon, and cellulose fibers are more preferable. Acrylic resins (especially acrylic acid) preferably have repeating units derived from esters thereof, methacrylic acid or esters thereof.

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 It is not less than 10 mm and not more than 90 mm, and more preferably not less than 20 mm and not more than 60 mm.

The diameter of the first fiber 20 is preferably not less than 10 μm and not more than 30 μm, more preferably not less than 15 μm and not more than 25 μm. On the other hand, the diameter of the second fiber 40 is preferably not less than 0.1 μm and not more than 9 μm, more preferably not less than 0.5 μm and not more than 5 μm.

The fibers with different fiber diameters may be fibers of the same composition or different compositions, and are preferably fibers of the same composition in the present invention. Also, the fibers may be different or the same in fiber length, but in the present invention, fibers of the same fiber length are preferred.

The weight per unit area of the fibers constituting the wiping sheet 10 is preferably from 1 g/m ² to 100 g/m ² on the wiping surface side, more preferably from 5 g/m ² to 50 g/m ² , and still more preferably 10 g /m ² or more and 30 g/m ² or less. On the other hand, on the surface opposite to the wiping surface, it is preferably 10 g/m ² to 50 g/m ² , more preferably 15 g/m ² to 30 g/m ² , still more preferably 20 g/m 2 ² or more and 25g/m ² or less.

In relation to the weight per unit area of fibers constituting the wiping sheet 10, the thickness T of the wiping sheet 10 is preferably at least 1 mm under a load of 40 Pa, more preferably at least 1.2 mm, and more preferably at least 1.5 mm. Also, under the same load, it is preferably 5 mm or less, more preferably 4 mm or less, and more preferably 3 mm or less. The thickness T of the wiping sheet 10 is preferably from 0.8 mm to 3 mm under a load of 370 Pa, more preferably from 0.9 mm to 2.8 mm, more preferably from 1 mm to 2.5 mm. By setting the thickness T of the wiping sheet 10 within this range, the wiping sheet 10 has sufficient rigidity and strength, and the operability at the time of wiping becomes favorable.

In the present invention, it is particularly preferable that fibers having different fiber diameters be entangled without thermal fusion. In this way, the voids between the fibers increase compared to the case of thermal fusion. As a result, when carrying a wiping liquid on the wiping sheet 10, the carrying amount of a wiping liquid increases.

The wet wiping sheet 10 wipes the surface to be wiped once by wiping once, and the amount of the wiping liquid released from the wiping surface to the surface to be wiped is preferably at least 0.5 g/pan, more preferably at least 0.7 g/pan, Furthermore, it is more preferably 1.0 g/pan or more. The upper limit of the amount released is actually 8 g/taste or less, preferably 7 g/taste or less, and more preferably 6 g/taste or less. If the amount of release is too small, sufficient wiping will not be possible, and if it is too large, wiping liquid residue will easily occur on the wiping surface. Here, the grid is 1820mm×910mm, and the area is 1.6552m ² .

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

The maximum liquid loading capacity of the wiping liquid that can be carried on the wiping sheet 10, that is, the initial liquid loading capacity, is as described in the following example describing the size of one wiping sheet 10. When it is set to 285mm×205mm, it is better It is 1 g/tablet or more, more preferably 10 g/tablet or more, still more preferably 12 g/tablet or more. The upper limit of the initial liquid load is actually 40 g/tablet or less, preferably 30 g/tablet or less, and more preferably 20 g/tablet or less.

In this way, it is possible to target a liquid release amount of more than 1g/pan per wipe, and it can last for more than 6 grains.

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

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

The wiping fluid may also contain additives. As additives, may be cited to improve flushing Polymers of acrylic acid, methacrylic acid, or maleic acid or their salts, and copolymers of maleic acid and other vinyl monomers or their salts, etc., for the purpose of effect. Further, water-soluble organic solvents such as bactericides, fragrances, fragrances, deodorants, abrasive particles, pH adjusters, alcohols, and the like can be mentioned.

The content of surfactants and additives as mentioned above is usually in the range used in wet wiping sheets.

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 production device 1 preferably used for the production of a wiping sheet 10 . The manufacturing device 1 includes a web forming unit 2 , an intertwining unit 3 , an electrospinning unit 4 , and a protrusion forming unit 5 .

The web forming part 2 forms a web of the first fibers 20 . The web forming part 2 is equipped with the carding machine 21 which forms a web using the 1st fiber 20 which is a raw material of the wiping sheet 10. As shown in FIG.

The intertwining part 3 intertwines the network of the first fibers 20 by water flow. The entanglement part 3 is equipped with the 1st water flow nozzle 31 which blows water flow to the web of the 1st fiber 20, and the 1st support belt 32 which consists of an endless belt. The first water flow nozzle 31 is located above the web of the first fibers 20 and the first support belt 32, and can blow high-pressure water flow over the entire width direction of the web of the first fibers 20. The first support belt 32 is disposed opposite to 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 fibers 20 entangled by blowing the water flow from the first water flow nozzle 31 is conveyed to the electrospinning unit 4 via the first support belt 32 .

The electrospinning part 4 generates the second fiber 40 including nanofibers by the electrospinning method, and accumulates them on one side of the entanglement body of the first fibers 20 entangled by the water nozzle 31 of the entanglement part 3 . The electrospinning unit 4 includes a spraying unit 41 that sprays the raw material solution of the second fiber 40 to perform electrospinning, and a capture electrode 42 that captures the jetted raw material solution as the second fiber 40 . The ejection unit 41 includes a supply unit for the raw material solution 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 part 41 . The capture electrode 42 is arranged to face the ejection unit 41 . The capture electrode 42 includes a conductive member and is grounded.

When a voltage is applied to the spraying part 41, the raw material liquid of the second fiber 40 is charged by electrostatic induction until it is sprayed from the spraying part 41, and sprayed in a charged state. The raw material liquid ejected in a charged state is subjected to the action of an electric field to cause self-repulsion of the raw material liquid, etc., and the second fiber 40 is produced as a nanometer-sized fine fiber (nanofiber). The generated second fibers 40 are randomly deposited on one surface of the intertwined body of the first fibers 20 running near the capture electrode 42, forming a fiber aggregate. By this electrospinning step, a laminate 50 of fiber aggregates including the first fibers 20 and the second fibers 40 is formed. The obtained laminated body 50 is conveyed to the protrusion forming part 5 .

As the raw material liquid of the second fiber 40 in the electrospinning method, a liquid obtained by dissolving or dispersing the high molecular compound constituting the second fiber 40 in a solvent, or a molten liquid obtained by melting the high molecular compound can be used. The method of using a liquid obtained by dissolving or dispersing a polymer compound in a solvent can also be called a solution-type electrospinning method, and the method of using a molten liquid obtained by melting a polymer compound can also be called a melt-type electrospinning method. Law. In the present invention, any electrospinning method can be used.

In the protrusion forming part 5 , water flow is blown to the laminate 50 of the fiber aggregate of the first fibers 20 and the fiber aggregate of the second fibers 40 to intertwine the first fibers and the second fibers and form the protrusions. The protrusion forming part 5 includes a second water flow nozzle 51 for blowing water flow from the first fiber 20 side to the laminate 50, a protrusion forming member 52 for forming a protrusion on the second fiber 40 side by the water flow, and a protrusion forming member 52 provided on the protrusion forming part. The second support belt 53 below the member 52, and the conveyor belt 54 for conveying the laminated body 50 formed with the protrusions to the downstream manufacturing step.

As shown in FIG. 2 , the second water flow nozzle 51 is located on the first fiber 20 of the laminate 50 On the side, the water flow can be blown over the entire width direction of the laminated body 50 . The convex part forming member 52 is located below the laminated body 50, and is arrange|positioned so that it may oppose the fiber aggregate of a 2nd fiber. As shown in FIG. 3 , a plurality of circular openings 52 a are regularly formed in the protrusion forming member 52 over the entire area. The protrusion forming member 52 is not particularly limited as long as it has openings, and perforated metal, plastic mesh, or the like can be used. Also, there is no particular limitation on the shape of the opening portion 52a. Besides the circle shown in FIG. 3, it may also be an ellipse, or a polygon such as a triangle, a quadrangle, or a pentagon. The protrusion forming member 52 may be integrated with the second support belt 53 by methods 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 on the side of the first fiber 20 makes the surface (first surface 50Y) on the side of the second fiber 40 of the laminate 50 form a convex portion. The upper surface of the component 52 is pressed against in a manner of being in close contact. At the same time, the fiber assembly of the first fibers 20 and the second fibers 40 located in the opening 52a protrudes in the opening 52a to form a plurality of protrusions 50A. At this time, the classification of the first fibers 20 and the second fibers 40 occurs, and at the top 50T of the convex portion 50A, the abundance ratio of the first fibers 20 in the top portion 50T of the entire fiber constituting the convex portion 50A becomes higher than that of the second fiber. 2. Existence ratio of fibers 40. At the same time, in the foot portion 50B of the convex portion 50A, the abundance ratio of the second fiber 40 in the foot portion 50B relative to the entire fiber constituting the convex portion 50A becomes higher than the abundance ratio of the first fiber 20 . Through these steps, the laminated body 50 in which the several convex part 50A was formed is obtained.

As shown in FIG. 5 , the width L of the opening 52 a of the protrusion forming member 52 is preferably 400 μm or more and 10 mm. By having this width L, the convex part 50A which has a favorable appearance and can reduce the resistance at the time of 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 not less than 800 μm and not more than 3 mm, more preferably not less than 900 μm and not more than 2 mm. By having the thickness in this range, 50 A of favorable convex parts can be formed in the laminated body 50.

As another embodiment of the protrusion forming part 5 (hereinafter referred to as the second embodiment), as shown in FIGS. 6 and 7, in addition to the protrusion forming member 52, a second protrusion forming member 520 may also be used. In the laminated body 50, two types of protrusions 50A and 520A of second protrusions are formed (hereinafter, in the second embodiment, the protrusions 50A are also referred to as first protrusions 50A). In the second embodiment, as shown in FIG. 6 , the second protrusion forming member 520 is arranged so as to overlap the upper portion of the above-mentioned protrusion forming member 52 . The second protrusion forming member 520 has a large number of quadrangular openings 520 a regularly formed over its entire surface. As shown in FIG. 8 , the width La of the quadrangular opening 520 a becomes larger than the width L of the opening 52 a of the protrusion forming member 52 . In this way, by stacking two kinds of protrusion forming members 52, 520, on the first surface 50Y side of the wiping sheet 10 (hereinafter, also referred to as the wiping sheet 10' in the second embodiment), the first protrusions 50A can be formed in a plurality of regularly arranged shapes, such as a shape protruding from the top of the second convex portion 520A.

According to the second embodiment in which two kinds of protrusion forming members 52, 520 are overlapped, on the side of the first surface 50Y of the wiping sheet 10', there are first protrusions 50A and macroscopic patterns larger than the first protrusions 50A. The second convex portion 520A (in the second embodiment is a diamond-shaped lattice pattern), and the first convex portion 50A is located in the second convex portion 520A to form a two-level step difference. In this case, at the top of the first convex portion 50A, the ratio of the first fibers 20 to the top of the entire fiber constituting the first convex portion 50A is higher than the ratio of the second fibers 40, and The abundance ratio of the second fiber 40 in the foot portion of the first convex portion 50A is higher than the abundance ratio of the first fiber 20 in the foot portion of the entire fiber constituting the first convex portion 50A.

In the second embodiment in which two types of convex portion forming members 52, 520 are stacked and used, as shown in FIG. The surface (first surface 50Y) on the side of the second fiber 40 is pressed against the second protrusion forming member 520 so as to be in close contact. At this time, the first fiber 20 and the second fiber 40 enter into the opening 520a, and A plurality of second protrusions 520A having a shape corresponding to the shape of the opening of the second protrusion forming member 520 is formed. Furthermore, the water flow blown from the second water flow nozzle 51 presses the second convex portion 520A so that the surface (first surface 50Y) on the second fiber 40 side is in close contact with the convex portion forming member 52, and the first convex portion 50A They are formed on the top of the second convex portion 520A in a plurality of regular arrangements. In this way, a plurality of first convex portions 50A are raised from the top of one second convex portion 520A, thereby forming a shape in which the first convex portion 50A and the second convex portion 520A have two levels of height difference. Through this step, it is also possible to obtain a laminate 50 in which a plurality of convex portions 50A are formed, as in the embodiment in which the convex portion forming member 52 is used alone.

The wiping sheet 10' of the second embodiment obtained through the above steps protrudes from the surface (second surface) 50X on the side of the first fiber 20 toward the surface (first surface) 50Y on the side of the second fiber to form a first protrusion. part 50A and the second convex part 520A. 50 A of 1st convex parts and 520 A of 2nd convex parts become a shape raised from the flat surface of 1st surface 50Y. Also, as described above, the first convex portion 50A is located inside the second convex portion 520A, and has a shape that protrudes 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 two levels of height difference is formed. The entire area of the second surface 50X can also be a flat surface by the manufacturing method of the wiping sheet 10' in the second embodiment, and the area 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 520 a of the second protrusion forming member 520 is preferably 400 μm to 10 mm, more preferably 420 μm to 8 mm. By having this width La, 2nd convex part 520A which has a good appearance and can reduce the resistance at the time of wiping can be formed in the laminated body 50.

As shown in FIG. 8 , the thickness Ta of the second protrusion forming member 520 is preferably not less than 600 μm and not more than 4 mm, more preferably not less than 700 μm and not more than 3 mm. By having a thickness within this range, it is possible to form the second protrusion having a good appearance on the laminate 50 and reducing resistance during wiping. Section 520A.

If return to Fig. 2 again, then finally, will form the laminated body 50 of convex portion 50A by convex portion forming portion 5, utilize conveyor belt 54 to convey toward downstream from convex portion forming portion 5, can obtain target dry wiping sheet 10 ( or wiping sheet 10'). And, will form the laminated body 50 of convex portion 50A by convex portion forming portion 5, after utilizing conveyor belt 54 from convex portion forming portion 5 toward downstream conveyance, also can further from the face corresponding to the 2nd face of wiping sheet 10 The wiping liquid is supplied and loaded on the side. By going through this step, the target wet wiping sheet 10 (or wiping sheet 10') can be obtained.

The loading amount of the wiping liquid when manufacturing the wet wiping sheet 10 (or wiping sheet 10') is as described in the embodiment of the size of one wiping sheet as described below. When it is set to 285mm×205mm, it is relatively It is preferably at least 6 g/tablet, more preferably at least 8 g/tablet, and still more preferably at least 10 g/tablet. The upper limit of the content of the wiping liquid is preferably 40 g/tablet or less, more preferably 30 g/tablet or less, further preferably 20 g/tablet or less. As a method of carrying the wiping liquid, methods such as spraying, coating, and immersion can be used.

The wiping sheet 10 (or wiping sheet 10') manufactured in this way can utilize the wiping sheet alone, or make it attached to cleaning utensils such as scrapers, and be used for buildings, cabinets, etc. such as floors and walls. Window glass, mirrors, doors, doorknobs and other building furniture, rugs, carpets, furniture such as desks and dining tables, 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 numbers and water pressures of the first and second water flow nozzles 31 and 51 may be the same or different.

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

This invention discloses the following wiping sheet and its manufacturing method further about said embodiment.

<1>

A wiping sheet comprising at least first fibers and second fibers with a smaller diameter than the first fibers, a fiber aggregate formed by intertwining these fibers, having a first surface used as a wiping surface, and a The second surface on the opposite side of the first surface; and the existence ratio of the second fiber becomes higher on the first surface than on the second surface; a plurality of convex parts are formed on the first surface side; relative to the above-mentioned convex parts The abundance ratio of the first fiber in the top of the whole fiber becomes higher than the existence ratio of the second fiber; the existence ratio of the second fiber in the foot of the whole fiber constituting the above-mentioned convex part becomes higher than the first fiber. Fiber presence ratio.

<2>

The wiping sheet according to <1> above, wherein the first fibers and the second fibers are entangled without being thermally fused to each other.

<3>

The wiping sheet according to <1> or <2> above, wherein the area ratio of the second fibers on the first surface is preferably 40% to 99%, more preferably 45% to 95%, More preferably, it is 50% or more and 90% or less, and the area ratio occupied by the second fiber on the second surface is preferably 0% or more and 55% or less.

<4>

The wiping sheet any one of said <1>-<3> which arrange|positions the several said convex part regularly.

<5>

The wiping sheet according to any one of the above <1> to <4>, wherein a region 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.

<6>

The wiping sheet according to any one of <1> to <4> above, wherein the entire second surface is a flat surface.

<7>

The wiping sheet according to any one of <1> to <6> above, wherein the convex portion is solid and filled with fibers.

<8>

The wiping sheet according to any one of the above <1> to <6>, wherein the convex portion is solid and 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 protrusions are regularly arranged on the first surface side of the wiping sheet.

<10>

The wiping sheet according to any one of <1> to <9> above, wherein the protrusions 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> above, wherein the protrusions have a width of 400 μm to 10 mm and a height of 110 μm to 25 mm.

<12>

The wiping sheet according to any one of the above <1> to <11>, wherein the convex portion is defined by its width and It is preferably at least 800 μm, more preferably at least 900 μm, and the width W is further preferably at most 8 mm, more preferably at most 5 mm.

<13>

The wiping sheet according to any one of the above <1> to <12>, which has the above-mentioned convex portion and a second convex portion including a macroscopic pattern larger than the above-mentioned convex portion on the first surface side, and the convex portion Located in the second convex portion to form a two-level step difference; at the top of the above-mentioned convex portion, the ratio of the presence of the first fiber to the top of the entire fiber constituting the convex portion becomes higher than the presence of the second fiber Ratio, and at the foot of the above-mentioned convex portion, the abundance ratio of the second fiber in the foot portion of the entire fiber constituting the convex portion becomes higher than the abundance ratio of the first fiber.

<14>

The wiping sheet according to <13> above, wherein the above-mentioned convex portion is formed on the top of the second convex portion larger than the above-mentioned convex portion.

<15>

The wiping sheet according to <13> above, in which a plurality of the above-mentioned 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 frictional force between the wiping object surface and the wiping sheet is preferably 55N/ ^m2 applied to a wiping sheet of a size of 10cm×25cm The resistance when wiping with pressure is 10N or less, more preferably 5N or less, more preferably 4N or less.

<17>

The wiping sheet according to any one of the above <1> to <16>, wherein the first The ratio of the first fibers to the second fibers is three times or more that of the second fibers on the basis of the number of the first fibers relative to the entire fibers constituting the convex portion.

<18>

The wiping sheet according to any one of the above <1> to <17>, wherein the ratio of the first fiber and the second fiber in the mountain foot of the convex portion is based on the number of fibers constituting the convex portion as a whole The second fiber is twice or more than the first fiber.

<19>

The wiping sheet according to any one of the above <1> to <18>, wherein the first fiber and the second fiber are polyester, polyamide, polyolefin, cellulose fiber, or various metals, glass, or minerals The raw material fibers are preferably polyester, polyamide, polyolefin, and cellulose fibers.

<20>

The wiping sheet according to any one of <1> to <19> above, wherein the first fiber and the second fiber are preferably fibers of the same composition.

<21>

The wiping sheet according to any one of <1> to <20> above, wherein the diameter of the first fibers is preferably from 10 μm to 30 μm, more preferably from 15 μm to 25 μm.

<22>

The wiping sheet according to any one of <1> to <21> above, wherein the diameter of the second fibers is preferably from 0.1 μm to 9 μm, more preferably from 0.5 μm to 5 μm.

<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 located on the second surface side.

<24>

The wiping sheet according to the above <23>, which has the release layer of the above-mentioned wiping liquid and the liquid retention layer carrying the wiping liquid, and the release layer includes the first surface.

<25>

The wiping sheet according to any one of <1> to <24> above, wherein when an imaginary circle with a diameter of 20 mm is drawn at an arbitrary position on the first surface, the number of the above-mentioned protrusions existing within the imaginary circle is 10 Above and below 60.

<26>

The wiping sheet according to any one of <1> to <25> above, wherein the weight per unit area of fibers constituting the wiping sheet is 1 g/m ² or more and 100 g/m ² or less on the side of the wiping surface.

<27>

The wiping sheet according to any one of <1> to <26> above, wherein the thickness of the wiping sheet is 1 mm to 5 mm under a load of 40 Pa.

<28>

A method of manufacturing a wiping sheet, which is a method of manufacturing a wiping sheet according to any one of the above <1> to <27>; in which a fiber assembly of the first fiber and a first fiber having a diameter smaller than the first fiber are combined 2. The laminated body of fiber aggregates of fibers is blown from the side of the first fiber aggregates in a state where the second fiber aggregates and the protrusion forming member having a plurality of openings face each other. The water flow makes the first fiber intertwine with the second fiber, and makes the above-mentioned fiber assembly located in the above-mentioned opening portion protrude in the opening portion.

<29>

The method for producing a wiping sheet according to <28> above, wherein a fiber aggregate of the second fibers is formed by a melt-type electrospinning method.

Example

Hereinafter, the present invention will be described in detail by means of examples. However, the scope of the present invention is not limited to this example.

[Example 1]

The wiping sheet 10 having the structure shown in FIG. 1 is manufactured using the manufacturing apparatus 1 and the protrusion forming member 52 shown in FIGS. 2 to 5 . As the first fiber 20 , a blend containing PET:acrylic:rayon=7:1.5:1.5 in mass ratio and having an average diameter of 11.4 μm was used. As the second fiber 40, polypropylene having an average diameter of 1 μm obtained by electrospinning was used. The basis weight of the first fibers 20 was set at 60 g/m ² , and the basis weight of the second fibers 40 was set at 5 g/m ² . The wiping sheet 10 is rectangular, its size is 285mm×205mm, and its thickness T is 1.6mm. The height H of the protrusion 50A on the first surface 50Y side of the wiping sheet 10 is 0.7 mm, and the width W is 2 mm. 34 convex parts 50A are arrange|positioned on average in the imaginary circle with a diameter of 20 mm. The area ratio occupied by the second fibers 40 on the first surface 50Y is 90%, and the area ratio occupied by the second fibers 40 on the second surface 50X is 5%. The ratio of the first fiber 20 in the top portion 50T of the entire fiber constituting the convex portion 50A is twice that of the second fiber 40 on an area basis (67% in terms of area ratio). The abundance ratio of the second fiber 40 in the mountain foot portion 50B of the entire fiber 50A is 1.1 times that of the first fiber 20 on an area basis (52% by area ratio).

The wiping sheet 10 of Example 1 was used as a wet wiping sheet carrying a wiping liquid. The wiping liquid is carried on at least the fiber aggregate located on the second surface side. The loading amount of wiping liquid is 20g/tablet. As the wiping liquid, a 0.01% by mass aqueous solution of a surfactant (EMULGEN 108, manufactured by Kao Corporation) was used.

[Example 2]

The wiping sheet in Example 1 does not carry the wiping liquid, except that it is the same as in Example 1 Manufacture the wiping sheet in this way. That is, the wiping sheet of Example 2 is a dry type.

[Comparative example 1]

As the wet wiping sheet, Scotch‧Brite (registered trademark) floor wet sheet manufactured by 3M Company was used. This wet wiping sheet is a fiber aggregate containing thin fibers and thick fibers, but does not have the protrusions of the present invention formed on the wiping surface.

[Comparative example 2]

As a dry wiping sheet, Scotch‧Brite (registered trademark) floor wet sheet manufactured by 3M Company was dried for 24 hours in an environment with a temperature of 20° C. and a relative humidity of 65%. This wiping sheet is a fiber aggregate containing thin fibers and thick fibers, but does not have the protrusions of the present invention formed on the wiping surface.

[Comparative example 3]

As the dry wiping sheet, an ultrafine adsorption dry sheet manufactured by Yamazaki Sangyo Co., Ltd. was used. This wiping sheet is a fiber aggregate containing thin fibers and thick fibers, but does not have the protrusions of the present invention formed on the wiping surface.

[Evaluation]

For the wiping sheets of each example and comparative example, a pressure of 55N/ ^m2 was applied, and the floor (Conbit new advance101, manufactured by ^WOODONE Co., Ltd.) was set as the surface to be wiped, and the area of 1.8m2 was wiped, and measured by the above method Resistance at this time. The results are shown in FIGS. 9 and 10 .

The resistance of Example 1 and Comparative Example 1, which are wet wiping sheets, were compared. As shown in FIG. 9 , the resistance of Example 1 was 2.7N. On the other hand, the resistance of Comparative Example 1 was 15.7N. From these results, it can be seen that the wet wiping sheet 10 of Example 1 has less frictional resistance at the time of wiping and has high operability.

The resistance of Example 2, which is a dry wiping sheet, and Comparative Examples 2 and 3 were compared. As shown in FIG. 10 , the resistance of Example 2 was 1.8N. On the other hand, the resistance of Comparative Example 2 was 2.2N, and the resistance of Comparative Example 3 was 4.1N. From these results, it can be seen that the dry wiping sheet 10 of Example 2 is the same as the wet wiping sheet 10 of Example 1, and the frictional resistance at the time of wiping is low, and the workability is high.

In particular, as clear from the comparison of Example 1 and Comparative Example 1 and Example 2 and Comparative Example 2, when the wiping sheet of the present invention is used wet, the reduction in frictional resistance becomes remarkable.

[Industrial availability]

According to the present invention, there are provided a wiping sheet which reduces frictional resistance at the time of wiping and improves operability at the time of wiping, and a manufacturing method thereof.

10‧‧‧Wiping sheet

20‧‧‧1st fiber

40‧‧‧Second fiber

50‧‧‧laminated body

50A‧‧‧convex part

50B‧‧‧The foot of the convex part

50C‧‧‧Concave

50T‧‧‧top of convex part

50X‧‧‧2nd surface (1st fiber 20 side surface)

50X'‧‧‧flat surface of the second surface

50Y‧‧‧1st side (wiping side)

50Y'‧‧‧flat surface of the first surface

H‧‧‧Height of convex part 50A

T‧‧‧thickness

W‧‧‧Width of convex part 50A

Claims (29)

A wiping sheet comprising at least first fibers and second fibers with a smaller diameter than the first fibers, a fiber aggregate formed by intertwining these fibers, having a first surface used as a wiping surface, and a The second surface on the opposite side of the first surface; and the existence ratio of the second fiber becomes higher on the first surface than on the second surface; a plurality of convex parts are formed on the first surface side; relative to the above-mentioned convex parts The abundance ratio of the first fiber in the top of the whole fiber becomes higher than the existence ratio of the second fiber; the existence ratio of the second fiber in the foot of the whole fiber constituting the above-mentioned convex part becomes higher than the first fiber. The presence ratio of fiber. The wiping sheet according to claim 1, wherein the first fibers and the second fibers are not entangled by thermal fusion. The wiping sheet according to claim 1, wherein the area ratio of the second fibers on the first surface is 40% to 99%; and the area ratio of the second fibers on the second surface is 0% or more And below 55%. According to the wiping sheet according to claim 1, a plurality of the above-mentioned protrusions are regularly arranged. The wiping sheet according to claim 1, wherein the region 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. The wiping sheet according to claim 1, wherein the entire area of the second surface becomes a flat surface. The wiping sheet according to Claim 1, wherein the above-mentioned convex portion is solid and filled with fibers. The wiping sheet according to claim 1, wherein the above-mentioned convex portion is a solid one filled with the first fiber and/or the second fiber. The wiping sheet according to claim 1, wherein the above-mentioned protrusions are regularly arranged on the first surface side of the wiping sheet. The wiping sheet according to claim 1, wherein the protrusions are regularly arranged along the length direction and/or along the width direction of the wiping sheet. The wiping sheet according to claim 1, wherein the above-mentioned protrusions have a width of 400 μm to 10 mm and a height of 110 μm to 25 mm. The wiping sheet according to claim 1, wherein the above-mentioned convex portion has a width of not less than 800 μm and not more than 8 mm. The wiping sheet according to claim 1, which has the above-mentioned convex portion on the first surface side, and a second convex portion containing a macroscopic pattern larger than the above-mentioned convex portion, and the convex portion is located in the second convex portion to form two grade Step difference; at the top of the above-mentioned convex portion, the ratio of the first fiber to the top of the entire fiber constituting the convex portion becomes higher than the ratio of the second fiber, and at the foot of the above-mentioned convex portion, The abundance ratio of the second fibers is higher than the abundance ratio of the first fibers in the mountain foot portion relative to the entire fibers constituting the convex portion. In the wiping sheet according to claim 13, the above-mentioned convex portion is formed on the top of the second convex portion that is larger than the above-mentioned convex portion. According to the wiping sheet according to claim 13, a plurality of the above-mentioned convex portions are formed on the top of the second convex portion. The wiping sheet according to claim 1, wherein the resistance of wiping the surface to be wiped is 10N or less when a pressure of 55N/ ^m2 is applied to the wiping sheet with a size of 10cm×25cm. The wiping sheet according to claim 1, wherein the ratio of the first fiber and the second fiber in the top of the above-mentioned convex portion is relative to the entire fiber constituting the convex portion, and the first fiber is the ratio of the second fiber on the basis of the number of fibers. more than 3 times. The wiping sheet according to claim 1, wherein the abundance ratio of the first fiber and the second fiber in the mountain foot of the above-mentioned convex portion is relative to the entire fiber constituting the convex portion, and the second fiber is the first fiber on the basis of the number of fibers. more than 2 times. The wiping sheet according to claim 1, wherein the first fiber and the second fiber are independent and are polyester, polyamide, polyolefin, cellulose fibers, fibers made of various metals, glass, or minerals. The wiping sheet according to claim 1, wherein the first fiber and the second fiber are fibers of the same composition. The wiping sheet according to claim 1, wherein the diameter of the first fibers is not less than 10 μm and not more than 30 μm. The wiping sheet according to claim 1, wherein the diameter of the second fibers is not less than 0.1 μm and not more than 9 μm. The wiping sheet according to claim 1, wherein the wiping liquid is carried on at least the fiber assembly on the second surface side. The wiping sheet according to claim 23, which has the wiping liquid release layer and the liquid retention layer carrying the wiping liquid, and the release layer includes the first surface. The wiping sheet according to claim 1, wherein when an imaginary circle with a diameter of 20 mm is drawn at an arbitrary position on the first surface, the number of the above-mentioned protrusions existing in the imaginary circle is 10 or more and 60 or less. The wiping sheet according to claim 1, wherein the weight per unit area of fibers constituting the wiping sheet is 1 g/m ² or more and 100 g/m ² or less on the side of the wiping surface. The wiping sheet according to claim 1, wherein the thickness of the wiping sheet is not less than 1 mm and not more than 5 mm under a load of 40 Pa. A method of manufacturing a wiping sheet, which is the method of manufacturing a wiping sheet according to Claim 1; a laminate of a fiber assembly of first fibers and a fiber assembly of second fibers having a smaller diameter than the first fibers In the state where the fiber assembly of the second fiber is opposed to the protrusion forming member having a plurality of openings, 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 above-mentioned fiber aggregates located in the above-mentioned openings are made to protrude in the openings. The method of manufacturing a wiping sheet according to claim 28, wherein a fiber assembly of second fibers is formed by a melt-type electrospinning method.

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