JP2005312608A - Wiping sheet and production method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wiping sheet which enables the removal of a stain existing on a surface with an unevenness of a submicron scale can be removed. <P>SOLUTION: The wiping sheet to be used is comprised of a sheet type basal material and a wiping layer having fine columnar structures. The stain existing in a very fine region can be removed by using the wiping sheet which is composed of the sheet type basal material and the wiping layer having the fine columnar structures. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a wiping sheet, and more particularly, to a wiping sheet capable of wiping off dirt existing in a very fine region including oil film and sticky dirt.

  Various non-woven wipers using ultrafine fibers have been proposed and are now widely proposed. For example, Patent Document 1 discloses a non-woven fabric for wipers that is excellent in cleaning effect and durability by forming irregularities on the surface of the non-woven fabric for wipes containing ultrafine fibers and forming an adhesive region on the entire surface of the non-woven fabric. Patent Document 2 discloses a wiping cloth comprising a knitted fabric made of ultrafine fiber filaments of 0.1 denier or less, and the knitted fabric does not substantially contain a hydrophilic substance or a conductive substance. It is disclosed. Further, Patent Document 3 discloses a wiping cloth capable of satisfactorily wiping off oil and fat stains adhering to a lens by reducing silk and using the obtained reduced silk as a nonwoven fabric.

JP Patent Publication No. 2003-230520 Japanese Patent Laid-Open No. 9-119067 Japanese Patent Laid-Open No. 8-103406

  However, in any case, since the nonwoven fabric uses ultrafine fibers, it is difficult to control the direction, length, size, and arrangement of each fiber on the nonwoven fabric surface. Further, the equivalent diameter of the fiber is an equivalent diameter of about several μm except for special ones. Submicron scale irregularities exist on the surface, and it is difficult to remove the dirt present in the irregularities.

  In view of the above technical problems, the present invention can form a very fine columnar structure whose length, direction, and arrangement are controlled on its surface, and remove dirt existing on the uneven surface on a submicron scale. The purpose was to provide a possible wiping sheet.

  The present inventor uses a micro-columnar structure whose shape, size, and arrangement are controlled in order to remove the dirt existing on the fine unevenness on the submicron scale, and scrapes the dirt from the inside of the unevenness of the corresponding part. We found that this problem can be solved by the following method.

  That is, first, the present invention is a wiping sheet comprising a sheet-like base material and a wiping layer, wherein the wiping layer has a fine columnar structure.

  Second, the sheet-shaped substrate is composed of a sheet-like base material and a wiping layer, and the wiping layer has a fine columnar structure, and the surface shape of the sheet-like base material is higher than the height of the columnar structure. The wiping sheet is characterized in that it has irregularities with an interval wider than the interval between the columnar structures.

  Third, a wiping sheet comprising a sheet-like base material and a wiping layer, wherein the wiping layer has a fine columnar structure, and the sheet-like base material is a porous body. .

  Fourthly, in the method of manufacturing a wiping sheet that includes a sheet-like base material and a wiping layer, and the wiping layer has a fine columnar structure, (1) a step of heating the sheet-like base material; A method for producing a wiping sheet comprising: a step of heating and pressing a mold having fine irregularities on a substrate; and (3) a step of peeling a mold having fine irregularities formed from the substrate.

  Fifth, in a method for manufacturing a wiping sheet that includes a sheet-like base material and a wiping layer, and the wiping layer has a fine columnar structure, (1) a base material is applied to a mold having fine irregularities. A wiping sheet comprising: a step, (2) a step of curing the base material on a mold having fine irregularities; and (3) a step of peeling the base material from the mold on which fine irregularities are formed. It is a manufacturing method.

  In the wiping sheet of the present invention, it is preferable that the columnar structure has an aspect ratio of 2 or more in order to remove dirt existing in fine submicron irregularities. By setting the aspect ratio to 2 or more, the tip of the columnar structure enters the fine irregularities, and dirt can be effectively removed. In addition, it is preferable that the equivalent diameter of the columnar structure is thin. Particularly, by setting the columnar structure to 1 μm or less, the tip of the columnar structure enters into the unevenness of submicron or less, and dirt can be effectively removed. Further, regarding the equivalent diameter, the fact that columnar structures having a plurality of equivalent diameters instead of a single equivalent diameter are formed in the same wiping layer is effective in removing dirt corresponding to the unevenness of the object surface having different shapes. Is preferable. In addition, the interval between the columnar structures is not a single interval, but a plurality of intervals exist within the same surface of the wiping layer, so that the columnar structures follow a concavo-convex shape of submicron or less where dirt exists. More preferred. The material of the columnar structure is not particularly limited, and the surface of the base material is deformed by pressurizing and heating a mold having nanoscale irregularities, or gold having fine irregularities formed thereon. Any material can be used as long as it can form a columnar structure by casting a base material on a mold and peeling off after curing. Specifically, polyethylene, polypropylene, polyvinyl alcohol, polyvinylidene chloride, polyethylene terephthalate, polyvinyl chloride, polystyrene, ABS resin, AS resin, acrylic resin, polyamide, polyacetal, polybutylene terephthalate, glass reinforced polyethylene terephthalate, polycarbonate, modified Thermoplastic resins such as polyphenylene ether, polyphenylene sulfide, polyether ether ketone, liquid crystalline polymer, fluororesin, polyarate, polysulfone, polyethersulfone, polyamideimide, polyetherimide, thermoplastic polyimide, phenol resin, melamine resin, urea Resin, epoxy resin, unsaturated polyester resin, alkyd resin, silicone resin, diallyl phthalate resin, poly Bromide bismaleimide, poly bisamide thermosetting resin triazole and the like, and it is possible to use two or more kinds of these blended material.

  As the material for the sheet-like substrate of the present invention, the same materials as those described above can be used. At that time, the effect of the present invention can be realized by the same material as the micro-columnar structure or a combination of different materials.

  It is preferable that the sheet-like substrate has irregularities larger than the height and interval of the columnar structures. By forming such irregularities, the fine columnar structure of the present invention follows the surface shape of the object even if the surface is a surface where dirt is attached and a submicron area and a larger area are mixed. , Can effectively remove dirt. Moreover, even when a porous body is used for the base material, it is preferable because the base material can be elastically deformed to obtain the same effect. It is also preferable to use an elastic body such as silicone rubber.

  As a method for producing the wiping sheet of the present invention, (1) a step of heating a sheet-like substrate, (2) a step of heating and pressing a mold having fine irregularities on the sheet-like substrate, (3) from the substrate It is preferable to create a fine columnar structure in which the shape, arrangement, etc. are controlled, from the step of peeling the mold on which fine irregularities are formed. Here, as a method of pressurizing and heating the mold to the sheet-like base material, the above-described mold and base material are arranged on a parallel plate, and after pressurizing and heating, the press transfer method is peeled off, and fine irregularities While rolling with a roller type transfer system and a plurality of heating rolls to form a fine columnar structure by linearly pressing a sheet-like substrate with the cylindrical mold Examples include, but are not limited to, a calendar formation method in which a pattern is transferred on the final roll. Further, the mold has a fine pattern to be transferred, and the method for forming the fine pattern on the mold is not particularly limited. For example, it is selected according to the shape of the desired fine structure, such as photolithography or electron beam drawing. The material of the mold may be any material having strength and workability with required accuracy, such as silicon wafer, various metal materials, glass, ceramic, plastic, and the like. Specifically, Si, SiC, SiN, polycrystalline Si, glass, Ni, Cr, Cu, and those containing one or more of these are preferably exemplified. In particular, when a roll mold is used, a Ni foil mold created using Ni electroforming can be used.

  According to the present invention, a wiping sheet comprising a sheet-like base material and a wiping layer and having a fine columnar structure is used for the wiping layer, so that dirt existing in a very fine region can be removed. Can be removed.

  Examples of the present invention will be described below.

[Example 1]
A wiping sheet as one embodiment of the present invention will be described with reference to FIGS. 1 and 2 are conceptual diagrams, and it should be noted that the pattern shape is simplified and overwritten. FIG. 1 is a schematic view of a process for producing a wiping sheet of the present invention, and is a schematic sectional view of each step. An example of the wiping sheet creation process of the present invention is shown below.
(a) First, a polystyrene sheet having a thickness of 50 μm and a size of 300 mm square was placed on the stage 1 as the sheet-like substrate 2. Next, corrugated concaves and convexes with a height difference of 10 μm and a pitch of 10 μm are formed, and fine holes 3 with an equivalent diameter of 180 nm, 250 nm, 500 nm, and a depth of 1 mm are formed on the surface. Ni
A metal mold 4 was prepared.
(b) Next, after the stage 1 and the mold 4 were heated to 160 ° C., the sheet-like substrate 2 was pressed at a surface thickness of 20 kgf / cm ² .
(c) After cooling the mold 4 and the stage 1 to 100 ° C. or less, the mold 4 was peeled from the sheet-like substrate 2 to prepare a wiping sheet 5.

  FIG. 2 shows a schematic external view of the wiping sheet of the present invention. A fine columnar structure 6 was formed on the entire surface of the substrate sheet 2, and a wiping sheet 5 having corrugated irregularities with a height difference of 10 μm and a pitch of 100 μm was obtained on the substrate surface. In addition, FIG. 3 shows an SEM photograph observing the surface shape of the wiping sheet prepared by the above method. It can be confirmed that an ultrafine structure having an equivalent diameter of about 90 nm including a fine columnar structure of 1 μm or less is formed.

  Next, the wiping property of the fine irregularities was evaluated using the wiping sheet of the present invention. As the evaluation substrate, a substrate having a plurality of grooves processed with a depth of 500 nm and a width of 250 nm to 10 μm on a Si wafer was used. After applying and drying oil-based ink on this evaluation substrate, wiping using the wiping sheet of the present invention was performed. SEM observation of the later evaluation substrate surface was performed. As a result, it was confirmed that 80% or more of dirt was removed in all the grooves.

[Example 2]
A wiping sheet which is one embodiment of the present invention will be described with reference to FIGS. FIG. 4 is a schematic cross-sectional view of a roller type transfer system for producing the wiping sheet of the present invention. The wiping sheet of the present invention was prepared by the following method.

First, a long polyamide sheet having a width of 200 mm and a thickness of 50 μm wound around a supply roll 7 is prepared. Next, equivalent diameter 200mmφ, width 300mm, effective mold transfer area 190
A roll-shaped die 8 having a built-in heater wound with a Ni power pole foil having a thickness of 50 μm in which fine holes 3 having a diameter of 180 nm, 250 nm, 500 nm and a depth of 1 mm are formed on the surface, and an equivalent diameter of 200 mmφ Then, the long polyamide film is sandwiched between transfer portions made of a pressure roll 9 having a width of 300 mm. Next, the substrate sheet after transfer was wound up on a take-up roll 10 and finally cut to create a wiping sheet. The transfer conditions were a linear pressure of 50 kgf / cm 2, a temperature of 200 ° C., and a feed rate of 10 mm / s.

  FIG. 5 shows a schematic external view of the wiping sheet of the present invention. A wiping sheet 5 was obtained in which fine columnar structures 6 having equivalent diameters of about 180 nm, 250 nm, and 500 nm were formed on the entire surface of the base sheet 2.

  Next, the wiping property of the fine irregularities was evaluated using the wiping sheet of the present invention. As the evaluation substrate, a substrate having a plurality of grooves processed with a depth of 500 nm and a width of 250 nm to 10 μm on a Si wafer was used. After applying and drying oil-based ink on this evaluation substrate, wiping using the wiping sheet of the present invention was performed. SEM observation of the later evaluation substrate surface was performed. As a result, it was confirmed that 80% or more of dirt was removed in all the grooves.

[Example 3]
A wiping sheet which is one embodiment of the present invention will be described with reference to FIG. FIG. 6 is a schematic process diagram for producing the wiping sheet of the present invention, and is a schematic cross-sectional view of each process. An example of the wiping sheet creation process of the present invention is shown below.
(a) First, an 8-inchφ Si mold 11 having micropores 3 with a diameter of 250 nm, a pitch of 500 nm, and a depth of 1 μm formed on the entire surface is prepared, and the fluorine mold release agent aquaphobeCF is provided on the surface.
The mold release process was performed by (Gerest Co., Ltd. product).
(b) Next, a varnish in which 20% PMMA was dissolved in a 1-acetoxy-2-ethoxyethane solvent was cast on the mold, and then baked on a hot plate at 90 ° C. for 20 minutes to form a wiping layer 16. .
(c) Next, as the porous sheet-like base material 13 on which the adhesive layer 12 is formed, the absolute bond (R)
(Manufactured by Japan Gore-Tex) is disposed on the wiping layer 5 and placed between the press die 15 and the press stage 14 in a lump from the Si mold 11 to the porous sheet-like base material 13 at 150 ° C. Bonding was carried out by applying pressure and heating for 10 s at a pressure of 10 kgf / cm ² .
(d) Finally, a wiping sheet 5Si mold in which the porous sheet-like substrate 13, the adhesive layer 12, and the wiping layer 16 are integrated to form a micro-columnar structure having a diameter of 250 nm, a pitch of 500 nm, and a height of 1 μm on the surface. 11 peeled off.

  Next, the wiping property of the fine irregularities was evaluated using the wiping sheet of the present invention. As the evaluation substrate, a substrate having a plurality of grooves processed with a depth of 500 nm and a width of 250 nm to 10 μm on a Si wafer was used. After applying and drying oil-based ink on this evaluation substrate, wiping using the wiping sheet of the present invention was performed. SEM observation of the later evaluation substrate surface was performed. As a result, it was confirmed that 80% or more of dirt was removed in all the grooves.

[Comparative Example 1]
Blend 65 parts by mass of polyester fiber with a fineness of 3.3 dtex and 35 parts by mass of core-sheath composite fiber (manufactured by Daiwabo) made of polyester with a core component of 1.7 dtex and polyethylene as a sheath component, and use a roller card. A card web and a water flow of 4 MPa were sprayed once each on the front and back of the web, and after air drying, heat treatment was performed at 140 ° C. for 3 seconds using a hot air processing machine to obtain a nonwoven fabric.

  Using this nonwoven fabric, the wiping property evaluation of fine irregularities was performed. As the evaluation substrate, a substrate having a plurality of grooves processed with a depth of 500 nm and a width of 250 nm to 10 μm on a Si wafer was used. After applying and drying oil-based ink on this evaluation substrate, wiping using the wiping sheet of the present invention was performed. SEM observation of the later evaluation substrate surface was performed. As a result, 50% or more of dirt remained in the grooves of 1 μm or less.

The schematic diagram which shows each process of a wiping sheet. Schematic overview of the wiping sheet. The principle cross-sectional schematic diagram of a roller type transfer system. The cross-sectional schematic diagram of a wiping sheet. The schematic diagram which shows each process of a wiping sheet. The process schematic at the time of creating a wiping sheet.

Claims (9)

  A wiping sheet comprising a sheet-like substrate and a wiping layer, wherein the wiping layer has a fine columnar structure.   In the wiping sheet comprising a sheet-like base material and a wiping layer having a fine columnar structure, the sheet-like base material has a height higher than the columnar structure on the surface and wider than the interval between the columnar structures. A wiping sheet characterized by having uneven spacing.   A wiping sheet comprising a sheet-like base material and a wiping layer having a fine columnar structure, wherein the sheet-like base material is a porous body.   4. The wiping sheet according to claim 1, wherein an aspect ratio representing a ratio between an equivalent diameter and a height of the columnar structure is 2 or more. 5. The wiping sheet according to claim 1, wherein the columnar structure has an equivalent diameter of 1.
A wiping sheet having a size of μm or less.   4. The wiping sheet according to claim 1, wherein the columnar structure has a plurality of types of equivalent diameters.   4. The wiping sheet according to claim 1, wherein there are a plurality of types of intervals between the columnar structures.   A method of manufacturing a wiping sheet comprising a sheet-like substrate and a wiping layer, wherein the wiping layer has a fine columnar structure, a step of heating the sheet-like substrate, and a mold having fine irregularities on the sheet-like substrate A method for producing a wiping sheet, comprising a step of heating and pressurizing and a step of peeling a mold on which fine irregularities are formed from a substrate. In the method of manufacturing a wiping sheet having a fine columnar structure in the wiping layer, the step of applying the base material to a mold having fine irregularities, A method for producing a wiping sheet, comprising: a step of curing on a mold having irregularities; and a step of peeling a substrate from a mold on which fine irregularities are formed.

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