JP2006051155A - Base material for wet wiping member, and wet wiping member using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a base material for a wet wiping member, which is excellent in shape retentivity in a wet condition, and in water retentivity or chemical solution retentivity, good in wiping performance, and low in physical acridity to a human body and to an implement, and to provide the wet wiping member per se. <P>SOLUTION: The base material for the wet wiping member, into which at least water and/or a chemical solution is impregnated, is formed of a non-woven fabric in which 60% or more fibers present at least on a single surface are made of cellulose continuous fibers having a fiber diameter of 2.9 to 7.1 μm, and a fiber orientation coefficient of the surface fibers falls in the range of 0.65 to 1.35. There is also provided the wet wiping member using the base material. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a base material for a wet wiping member for wiping a human body or an instrument represented by a hand towel, wet tissue, clean cotton or various fine powder powders or a human or objective wiper, OA cleaner, etc. The present invention relates to a wiping member. More specifically, the base material for the wet wiping member, which has excellent shape retention properties when wet, water or chemical solution retention properties, has good wiping properties, and has low physical intensities to the human body and instruments, and wetness The present invention relates to a wiping member.

  Cellulose-based sheets such as paper and non-woven fabric are used for base materials for wet wiping members such as wet towels and wet tissues in order to improve liquid retention. However, the cellulosic sheet has a problem in handling properties due to a decrease in strength when wet or poor shape retention. In order to improve the handleability, for example, in hand towels, measures have been taken to improve the shape retention when wet by bonding to a film, but there is a drawback that the sheet becomes hard. Moreover, when using the sheet | seat made from the short fiber including paper as a base material, possibility that a short fiber would fall to a wiping surface and contaminated a wiping surface was a very large thing.

  In order to solve these problems, a regenerated cellulose continuous long-fiber nonwoven fabric proposed in Patent Document 1 or a lyocell long-fiber nonwoven fabric produced by the method described in Patent Document 2 is used as a substrate for a wet wiping member. For example, when a man's face is wiped off, even if the base material is caught by a short beard, the fibers constituting the nonwoven fabric are long fibers, so they do not fall off and the face is very unlikely to be contaminated. However, since it easily swells in a wet state, the wet strength decreases, and the elongation increases, the substrate for a wet wiping member used by impregnating with water or a drug has a shape retention property when wet. There was a problem in handling property because it was insufficient. Further, since the fiber diameter is large, the number of fibers per contact area is reduced, and the wiping property is not sufficient. Further, in order to improve the wiping property of the wet wiping member, means for physically improving the wiping property by embossing the substrate or providing an opening or a recess is known. Such physical means did not follow the surface contamination, and sufficient wiping property was not obtained.

For this reason, Patent Document 1 proposes a sheet made of a split fiber of synthetic fiber. When this is used for a substrate for a wet wiping member, the number of fibers per contact area is large, and the wiping surface Although it adheres well to dirt and provides a sufficient wiping effect, for example, when it is used on the human body, it has excessive frictional resistance when rubbed against the skin, and it is likely to cause scratches due to friction in people with weak skin. there were. In addition, since synthetic fibers have low liquid retention, when impregnated with water or a chemical solution to make a wet wiping member, the impregnating solution is small and the effect of the drug is reduced, or there are many impregnating solutions and the surroundings are dripped. And sometimes it was contaminated. Further, Patent Document 3 proposes a cellulose continuous fiber non-woven fabric having a fine fiber diameter of 0.1 dtex to 0.6 dtex, but if this non-woven fabric is used as a substrate for a wet wiping member, sufficient wiping is performed. However, as a substrate for a wet wiping member used by impregnating with water or chemicals, there is a problem in handling property due to insufficient shape retention when wet.
JP 2003-339567 A Special table 2002-521585 gazette JP 2003-306860 A

  The present invention provides a substrate for a wet wiping member having excellent shape retention properties when wet, water or chemical solution retention, good wiping properties, and low physical irritation to the human body and instruments, and wet cleaning. An object is to provide a wiping member.

In order to solve the above-mentioned problems, the present inventors have reduced the single yarn fineness constituting the cellulose fiber nonwoven fabric and controlled the orientation of the fibers constituting the nonwoven fabric, so that the shape retention when wet is good. The inventors have found that the wiping property can be improved, and that it is difficult to damage the member to be wiped such as skin and equipment, and the present invention has been made.
That is, the present invention is as follows.
(1) At least 60% of the number of fibers on one surface includes a nonwoven fabric composed of cellulose long fibers having a fiber diameter of 2.9 to 7.1 μm, and the fiber arrangement coefficient on the surface is 0.65 to 1.35. There is a substrate for a wet wiping member.
(2) The wet wiping member base material according to claim 1, which comprises 30% by weight or more of cellulose long fibers.
(3) The wet wiping member base material according to claim 1 or 2, wherein the cellulose long fibers are regenerated cellulose continuous long fibers.
(4) In the wet wiping member impregnated with at least water and / or a chemical solution, the wet wiping member base material is the wet wiping member according to any one of claims 1 to 3.

  According to the present invention, a base material for a wet wiping member having excellent shape retention properties when wet, water or chemical solution retention properties, good wiping properties, and low physical irritation to the human body and instruments, and A wet wiping member can be obtained.

The present invention will be specifically described below.
The nonwoven fabric used for the substrate for the wet wiping member of the present invention is a cellulose long fiber having a fiber diameter of 2.9 to 7.1 μm, preferably 2.9 to 6.5 μm, more preferably 2.9 to 5.8 μm. The nonwoven fabric occupies 60% or more, preferably 80% or more, and most preferably 100% of the number of fibers on one surface of the nonwoven fabric.
The cellulose long fiber as used in the field of this invention means the lyocell which is a refined cellulose long fiber, and the regenerated cellulose continuous long fiber. When the nonwoven fabric used for the substrate for wet wiping members of the present invention is a nonwoven fabric composed of 100% cellulose long fibers, for example, a long fiber nonwoven fabric such as lyocell, which is a purified cellulose described in JP-T-2002-521585. Or, for example, a regenerated cellulose continuous long fiber obtained by continuously spinning a rayon stock solution of cupra ammonium method on the net by the flow-down tension spinning method, and making the nonwoven fabric by tangling the fibers by self-adhesion of the fibers themselves or hydroentangling as necessary Nonwoven fabric may be mentioned. In the case of a cellulose long-fiber nonwoven fabric, the constituent fibers are long fibers, and therefore, the dropout of the fibers is less than that of the cellulose short-fiber nonwoven fabric, which is preferable.

The fiber diameter here means the diameter of the fiber when observed at a magnification at which the single fiber is about 1 cm in the electron micrograph of the nonwoven fabric surface. In the present invention, the fiber diameter is measured at an arbitrary 200 points on the surface of the nonwoven fabric, and the abundance ratio is 60% or more, that is, 120 points or more are composed of fibers having a fiber diameter of 2.9 to 7.1 μm. It means being.
When the fiber diameter of the cellulose fiber nonwoven fabric is 2.9 to 7.1 μm, the number of self-adhesion points and the degree of entanglement of the fibers themselves are increased as compared with the conventional cellulose fiber nonwoven fabric having a fiber diameter larger than this range. , Elongation is regulated, and shape retention during drying and wetting is improved. If the fiber diameter is smaller than the above range, the single fiber may be cut and fluffed at the time of manufacture, or the single fiber may be easily cut by friction during use as a product, and the dropped fiber may increase. . Therefore, it is not preferable that the fiber diameter is smaller than the above range because the characteristics of the long fiber nonwoven fabric are particularly impaired.

  Moreover, in the nonwoven fabric used for the base material for wet wiping members of the present invention, the one-side surface is a surface on which cellulose continuous fibers having a fiber diameter of 2.9 to 7.1 μm can be effectively used, and only on one side depending on the purpose of use. Alternatively, both sides may have a fiber diameter in this range. When the cellulose long fiber having a fiber diameter of 2.9 to 7.1 μm is less than 60% of the number of fibers on both side surfaces of the nonwoven fabric, it is possible to obtain a product that can satisfy the form retention and the wiping property as the intended use. I can't. In addition, when the cellulose long fiber having a fiber diameter of 2.9 to 7.1 μm is 60% or more of the number of fibers on both side surfaces of the nonwoven fabric, for example, in the case of a wet tissue for sterilization that performs sterilization by impregnation with a chemical solution, Even if the chemical solution evaporates slightly, it is preferable from the viewpoint that a decrease in sterilization efficiency can be suppressed by a scraping effect by the fiber.

The nonwoven fabric used for the base material for wet wiping members of the present invention has a fiber arrangement coefficient of 0.65 to 1.35, preferably 0.75 to 1.25. The fiber alignment coefficient here means that measured by the following method.
A 20 cm square sample (sample) is prepared, and fixed to a cylinder having a diameter of 12 cm with a rubber band or tape in a state where no wrinkles are formed on the surface of the sample. Add 10 ml of killer whale stamp ink aqueous dye system S-1 (red) to 1 liter of distilled water to prepare an evaluation solution. The evaluation liquid is injected into a burette having a tip diameter of 0.7 mm. As shown in FIG. 1, a sample, a burette, and a camera are set. The camera is fixed and the burette is fixed laterally moving. The camera position is set 10 cm above the sample surface, and the burette position is set 5 cm above the sample surface. The evaluation solution is dropped on 5 drops (0.05 ml) of the sample at a rate of about 0.01 ml per drop, and at the same time, the burette is moved sideways to take a photograph of the diffusion state after 10 seconds. At this time, a JIS standard metal scale is placed on the surface of the sample so that it can be converted into an actual diffusion area as shown in a photograph. The diffusion area can also be obtained from the photograph by image processing or the like.

A fiber arrangement coefficient is measured using the obtained photograph. Usually, the liquid diffuses in an elliptical shape. The diameter a of the ellipse in the machine axis direction and the diameter b in the direction perpendicular to the machine axis are measured, and the fiber arrangement coefficient c is calculated by the following equation.
Fiber arrangement coefficient c = b / a
The fiber arrangement coefficient is a coefficient indicating a diffusion state when the liquid is dropped, and indicates the fiber arrangement direction because the diffusion of the liquid has a high correlation with the fiber arrangement direction. When the fiber arrangement in the machine axis direction is large, the fiber arrangement coefficient is less than 1. If the arrangement of fibers in the machine axis and the direction perpendicular to the machine axis is the same, the liquid diffusion state is circular, and in this case, the fiber arrangement coefficient is 1. Further, when there are more fibers arranged in the direction perpendicular to the machine axis than in the machine axis direction, the fiber arrangement coefficient exceeds 1.

When the fiber arrangement coefficient is less than 0.65, the fibers are mainly arranged in the machine axis direction, and the number of entanglement and coupling with the fibers existing in the direction perpendicular to the machine axis decreases. The form retainability is small, the elongation in the direction perpendicular to the machine axis increases, the width becomes easy to enter, and tearing easily occurs in the machine axis direction.
On the other hand, when the fiber arrangement coefficient exceeds 1.35, the fibers are mainly arranged in the direction perpendicular to the mechanical axis, and the elongation of the nonwoven fabric is greatly influenced by the tissue elongation, and the influence of the elongation of the fiber itself is reduced. For this reason, although tissue elongation occurs, the number of entanglements and bonding points is very large, so even if tension is applied in the machine axis direction, the influence in the width direction does not increase. However, when the fiber arrangement coefficient exceeds 1.35, it becomes a very hard nonwoven fabric, which may cause trouble in actual use.

  As described above, the elongation at break and the fiber arrangement coefficient in the machine axis direction can be obtained by controlling the single fineness of the fibers forming the nonwoven fabric and the arrangement direction of the fibers in the machine direction during production. By reducing the single fineness, the number of fibers constituting the non-woven fabric with the same basis weight increases compared to the one with a large single fineness. The number of entanglement points increases significantly. By increasing the restraint point, a nonwoven fabric that is difficult to stretch, that is, has a low elongation at break, is formed. For example, in a regenerated cellulose continuous long fiber nonwoven fabric, web formation is performed by dispersing the yarn on a net or the like after spinning. It is no exaggeration to say that the mechanical properties in the machine axis direction and the direction perpendicular to the machine axis are determined by the state of yarn dispersion at this time. The control of the dispersion state can be adjusted, for example, by applying vibration in the traveling direction (machine axis direction) and the vertical direction (width direction) to the net on which the web is formed, and drawing a sin curve on the spun yarn. When the frequency and the vibration width in the width direction are increased, a nonwoven fabric that does not easily stretch in the machine axis direction can be obtained. Since these properties are improved not only in a dry state but also in a wet state, the shape retention is improved, so that the shape retention sufficient for impregnation with the water and / or drug of the present invention can be obtained.

In order to obtain a cellulose long fiber nonwoven fabric having a fiber diameter of 2.9 to 7.1 μm, for example, when a regenerated cellulose long fiber nonwoven fabric is obtained using a cupra ammonium ammonium rayon stock solution, the diameter of the spinning nozzle for spinning the stock solution is conventionally set. It can be suitably obtained by adjusting the viscosity of the undiluted solution and the undiluted solution temperature, controlling the coagulation rate, and taking a higher draw ratio than before.
The nonwoven fabric used for the substrate for a wet wiping member of the present invention preferably contains 30% by weight or more of cellulose long fibers, more preferably 60% by weight or more, and most preferably 100% by weight. Liquid retention improves by containing a cellulose long fiber. Cellulose fibers are excellent in liquid absorption performance, particularly water absorption performance. Among them, regenerated cellulose fibers and purified cellulose fibers are preferable because they have excellent water absorption performance compared to natural cellulose fibers such as cotton. When the cellulose long fiber is less than 30% by weight, the liquid retention is poor, and it may be difficult to satisfy the wiping in the wet state which is the object of the present invention.

As for the nonwoven fabric used for the base material for wet wiping members of this invention, 80% or more of wet form retention is preferable, More preferably, it is 90% or more. The wet form retention rate here is measured by the following method.
FIG. 2 schematically shows the measurement method. A sample is prepared in a size of 5 cm × 12 cm so as to be vertically long in the machine axis direction of the nonwoven fabric, and a measurement part is created by marking the center part of the upper and lower parts of 1 cm. 10 times the sample mass (W1) of pure water is uniformly applied to the sample. 1 cm above and below the sample is sandwiched between sample holding plates and fixed. After 30 wt% of the load of the sample mass per 1 m ² (bottom of the sample holding plate is set to 10 wt% of the sample mass per 1 m ^2, load to this and plus) was suspended for 30 seconds over, except Weight (remove the lower sample holding plate), and after 30 seconds, measure the length L (cm) of the measurement portion, that is, the length between the sample holding plates. The initial sample length (the length between sample holding plates before loading) is 10 cm, and the wet form retention rate is calculated by the following equation.
Wet form retention rate (%) = (10− (L−10)) / 10 × 100

The wet form retention rate greatly correlates with the handleability at the time of wiping with a nonwoven fabric in a wet state. When the wet form retention rate is 80% or more, the non-woven fabric does not have a joll when wiping in a wet state, the handleability is good, and the non-woven fabric is not torn, so that the wiping surface is re-contaminated. There is no.
The wet form retention rate can be controlled by the arrangement direction of the fibers forming the above-described nonwoven fabric, the entangled state of the fibers, that is, the abundance of single fibers. In order to improve the wet form retention rate, the number of fiber entanglement points can be increased by increasing the number of fibers arranged in the direction perpendicular to the mechanical axis, decreasing the single fiber density of the nonwoven fabric, and increasing the number of fibers present. By increasing, the wet form retention rate can be made suitable.

The nonwoven fabric used for the substrate for the wet wiping member of the present invention preferably has a white coefficient of 7 or more, more preferably 10 or more. The white coefficient as used in the field of this invention means what was calculated | required by the following measurements. Measurement is performed in a state where 12 samples are stacked. The measurement surface is a surface where the fiber diameter is defined. Tristimulus values of X, Y, and Z from the average values measured five times using a C light source, including a 2 ° field of view, specular gloss, and the ultraviolet region of the light source with a standard color management system Macbeth CE-3000 manufactured by Sakata Inx Co., Ltd. The whiteness and yellowness are calculated from the following equations.
Whiteness = 4 (0.847Z) -3Y
Yellowness = 100 (1.28X-1.06Z) / Y
In addition, as long as the measurement principle and the light source are the same, the measurement may be performed with another measuring device.
The white coefficient is calculated by the following equation.
Whiteness coefficient = whiteness / yellowness The whiteness coefficient is a coefficient value that more significantly indicates the whiteness of the fabric. Usually, a white fabric has a large whiteness and a small yellowness. Therefore, if the white coefficient is used, the degree of whiteness can be grasped more clearly.

  The white coefficient of the nonwoven fabric used in the substrate for the wet wiping member of the present invention is improved because the fineness is small, so that the inside of the fiber can be refined at the time of spinning, and irregular reflection occurs on the nonwoven fabric surface because the singleness is small. It is estimated that the whiteness is improved and the yellowness is lowered, so that the white coefficient is greatly improved. If the fiber diameter does not satisfy the above conditions, the white coefficient may not be 7 or more. Therefore, the non-woven fabric used in the present invention is a non-woven fabric having a very high whiteness and a low yellowness without performing bleaching or fluorescent whitening treatment. When the whiteness coefficient is less than 7, for example, when used for pharmaceutical or food use, cleanliness is lowered. In order to improve the white coefficient, it is possible to improve by controlling the fiber diameter and the scouring conditions during spinning as described above. Note that this rule does not apply to colored products such as dyed products. This is a rule for a color that is generally similar to white. In this case, when the yellowness is a negative value, the white coefficient is 7 or more.

The nonwoven fabric used for the substrate for wet wiping members of the present invention preferably has a basis weight of 8 to 150 g / m ² , more preferably 10 to 120 g / m ² , still more preferably 20 to 100 g / m ² , and a thickness. 0.03-1 mm is preferable, More preferably, it is 0.05-0.8 mm. The basis weight and thickness can be appropriately selected depending on the application. When the basis weight is in the above range, the strength as a non-woven fabric is high, it is difficult to break when it is made into a product, there is no problem in actual use such as the occurrence of lint, and the fiber filling density is moderate Therefore, it is soft and has excellent wiping properties.

The nonwoven fabric used for the base material for wet wiping members of the present invention may have a pattern formed with openings, recesses, irregularities and the like. The shape of the opening, the recess, and the mesh pattern may be appropriately selected depending on usage. For example, an independent pattern such as an elliptical shape, a circular shape, a square shape, a rectangular shape, a rhombus shape, or a combination of concave and convex shapes, for example, a herringbone shape pattern may be selected as appropriate. In addition, the arrangement pattern, for example, staggered arrangement with independent openings and recesses may be selected as appropriate. However, in the case of providing a separate opening or recess of the pattern described above, the area per one opening or recess is preferably 0.05 to 10 mm ^2, more preferably 0.1 to 5 mm ^2, more preferably Is 0.2 to ^2.5 mm ² . If the area per opening or recess is in the above range, contribution to wiping can be effectively obtained, and even if the object to be wiped passes through the opening or recess, Will not pollute. The area per opening or recess is binarized by placing, for example, black colored paper on the back side of the nonwoven fabric, that is, in a state where it can be separated into black and white, so that the opening or recess can be distinguished. Thus, it may be obtained by image processing or the like.

In addition, such surface modification is performed, for example, by treating the nonwoven fabric with a high-pressure liquid flow in a state where the nonwoven fabric is placed on a mesh-like net, so that the nonwoven fabric fibers on the net entanglement point are surrounded by the high-pressure liquid flow It can obtain suitably by being pushed. Further, for example, a method of so-called embossing, in which an uneven pattern is formed on the surface of a metal roll and an uneven shape is formed through a nonwoven fabric while applying pressure between the metal roll and the rubber roll, can be suitably obtained.
Depending on the presence or absence of a mesh pattern on the surface of the wiper, it is possible to control functionality such as wiping property and liquid permeability and to improve design properties.
If the nonwoven fabric used for the base material for wet wiping members of the present invention is within the range specified above, for example, yarns having different single fineness may be mixed, or may be combined with other materials or other nonwoven fabrics. It may be. By such means, it is possible to give higher functionality.

For example, the strength may be increased by laminating or adhering a film, or the cellulose nonwoven fabric may be stacked on a spunbond which is a synthetic fiber nonwoven fabric and three-dimensionally entangled with a high-pressure liquid flow. Alternatively, short fibers may be inserted between the long fiber nonwoven fabrics and combined with a high-pressure liquid flow to reduce the fiber packing density and improve the liquid retention.
A preferred embodiment of the nonwoven fabric used for the substrate for the wet wiping member of the present invention is a cellulose continuous long fiber nonwoven fabric. For example, Benize (registered trademark) manufactured by Asahi Kasei Fibers Co., Ltd. corresponds to this. The manufacturing method of the cupra nonwoven fabric is to extrude a stock solution in which a cotton linter whose degree of polymerization has been removed and dissolved in a copper ammonium solution is removed from a spinneret (spinner) having pores (stock solution discharge holes), and together with water The inside of the funnel is dropped and deammoniated to solidify the stock solution, and then stretched, and then shaken onto a net to form a web. At this time, the fiber that is shaken down to the net draws a sin curve by vibrating the net in a direction perpendicular to the traveling direction.

  Stretching at the time of spinning can be 100 to 500 times, and the stretching ratio can be arbitrarily adjusted by changing the shape of the spinning funnel and the amount of spinning water flowing down. By changing the draw ratio, the single fineness and the strength of the nonwoven fabric can be changed. It is also possible to control low-molecular weight cellulose, so-called hemicellulose, remaining in a small amount in the stock solution by changing the amount of spinning water and temperature. Further, by controlling the traveling speed and vibration width of the net, it is possible to control the fiber arrangement direction and control the strength, elongation and the like of the nonwoven fabric. The shape of the spinning funnel is preferably a rectangular shape, and the length of the spinning funnel to be flowed down is preferably 100 to 400 mm, and the slit width of the flowing down outlet is preferably 2 to 5 mm. The diameter of the stock solution discharge hole of the spinning nozzle used for spinning is preferably 0.1 to 0.5 mm, and the shape is preferably round.

  Moreover, it is preferable to laminate | stack a web from the meaning which ensures the uniformity of a nonwoven fabric, and the lamination | stacking number of sheets is preferable 3-10 sheets. Produces a nonwoven fabric in which the laminated web is entangled with high-pressure water flow after regenerating or scouring cellulose in the web state, for example, by the method described in Japanese Patent Nos. 787914 and 877579. You can also At this time, in order to impart design properties, it is possible to make holes or irregularities in the nonwoven fabric depending on the conditions of the high-pressure water flow and the net pattern disposed below and / or above the nonwoven fabric. The obtained nonwoven fabric can be obtained as a dried or wound product. Since the process from spinning to winding is performed in a series of steps, the fibers are connected continuously without being cut.

As for the physical irritation of the nonwoven fabric used for the base material for wet wiping members of the present invention, the maximum scratch depth is preferably 3 μm or less, more preferably 1.5 or less, and most preferably 1.0 μm or less. The physical irritation referred to in the present invention means that measured by the following method. 0.2 g of agar (AGAR POWDER, manufactured by Wako Pure Chemical Industries, reagent) and 8 g of gelatin (manufactured by DIFCO, reagent) were dissolved in 100 g of water, and then dispensed in a petri dish so that the surface was flattened and solidified in a refrigerator. An object is to be wiped off. Three samples of 5 cm × 10 cm are cut out from an arbitrary location on the wet wiping member and attached to a friction terminal of a friction feeling tester (KES-SE) manufactured by Kato Tech Co., Ltd. The sample and the object to be wiped are rubbed once using the friction tester under the conditions of a contact pressure of 4.9 × 10 ³ Pa, a contact area of 1 cm ² , and a friction distance of 2 cm. Using a non-contact type laser surveying machine, the surface of the object is rubbed with a non-contact type laser surveying instrument using a non-contact type laser surveying machine. Measure the maximum depth of scratches by using a non-contact laser surveying instrument. It shows that it is easy to damage a target object, so that the value of maximum depth is large. The physical stimulation of the nonwoven fabric is preferably a long-fiber nonwoven fabric because if fiber ends, crimps, or the like are present on the nonwoven fabric surface, they cause damage to the object to be wiped off. Furthermore, it is preferable that the surface fibers of the nonwoven fabric are soft when rubbing against the object to be wiped in that the physical stimulus stress is low, and when used as a substrate for wet wiping, rayon or cupra having a low wet stress is used. Such cellulosic fibers are most preferred. The physical irritation of the nonwoven fabric decreases when the frictional resistance between the object to be wiped and the nonwoven fabric is excessive, and increases when the surface fibers of the nonwoven fabric become extremely thin and the frictional resistance is excessive. A long-fiber nonwoven fabric made of split fibers with a surface fiber diameter of 2 μm or less does not have fiber ends or crimps, but the stress of the surface constituent fibers is small, but the frictional resistance is excessive, resulting in physical irritation Becomes larger.

Hereinafter, the wet wiping member using the base material for wet wiping members of the present invention will be described.
The wet wiping member as used in the present invention refers to a wiping cloth which is usually used in a wet state, such as a towel, wet tissue, clean cotton, etc., that is, in a state impregnated with water and / or a chemical solution.
In the wet wiping member of the present invention, as other additives, additives used in ordinary wet wiping members, for example, as a moisturizing agent such as ethanol or isopropyl alcohol as a bactericidal agent or a drying rate improver. Glycerin, propylene glycol, polyethylene glycol, and the like, and perfume, antibacterial agent, disinfectant, thickener, pigment, antioxidant, and surfactant may be added in an appropriate amount depending on the application. When alcohol is added, ethanol with less toxicity is preferable from the viewpoint of safety.

100-400 weight% is preferable with respect to a base material weight, and, as for the amount of water and / or chemical | medical solution provided to the base material of the wet wiping member of this invention, More preferably, it is 150-300 weight%. If the amount of water and / or chemical solution to be applied is less than 100% by weight, the water and / or chemical solution evaporates during storage, and the wet state cannot be maintained or the wiping effect during wiping may be reduced. is there. If the amount of the applied chemical solution exceeds 400% by weight, the chemical solution may drip during cleaning to stain the floor or the like, or a large amount of water and / or chemical solution may remain on the wiping surface, leaving a wiping trace.
The form of the wet wiping member of the present invention is usually a packaging body that is housed in a container formed so that the inside can be sealed, and the base material for the wet wiping member of the present invention can be pulled out one by one from the container. The form is not particularly limited. For example, it may be a cylindrical plastic container storing the base material for the wet wiping member of the present invention wound in a roll shape, or a pillow package or a paper container stored in a folded state one by one. It may be in the form.

  The manufacturing method of the wet wiping member of this invention is not limited. For example, the base material for the wet wiping member of the present invention wound in a roll shape is stored in a cylindrical plastic container that is opened only in one direction, impregnated with a certain amount of chemical solution, and heat-sealed at the top with a plastic sheet or the like And a method of fitting a lid having a mouth may be used. A method of storing a non-woven fabric folded one by one in a bag-made container that has been opened in only one direction with a plastic sheet or the like, impregnated with a certain amount of water and / or a chemical solution, and heat-sealing the mouth 1 A method of storing a plastic sheet or the like while making a bag by impregnating a certain amount of water and / or chemical solution in a folded state one by one, and making water and / or chemical solution constant while pulling out a sheet from a nonwoven fabric roll After impregnating the amount, it may be cut and folded one by one, rewinded into a roll, and stored in a container, or a production method in which these are combined.

  The step of impregnating the base material for the wet wiping member of the present invention with water and / or a chemical solution may be before or after slitting the roll-shaped nonwoven fabric, and may be before or after storing the base material in the container. The same applies to the case where the sheets are folded one by one, and the step of impregnating the base material with the chemical solution may be performed before or after the folding, or a method in which these are combined.

The present invention will be described based on examples.
Measurement methods, evaluation methods, etc. are as follows.
(1) Confirmation of weight percent of cellulose fiber The base material is analyzed with an electron microscope, a differential calorimeter, IR, etc., and fibers other than cellulose fiber are mixed, and the official moisture content of the mixed material is 0.5%. In the case of less than this, the weight% of cellulose fibers is determined by the following method. The official moisture content is the value published in the fiber handbook edited by the Japan Chemical Fiber Association. When the official moisture content of the mixed material is 0.5% or more, the mixed material is dissolved to determine the weight percent of the cellulose fiber.
A sample of 10 cm × 10 cm is prepared. The sample is placed in a weighing bottle and dried at 105 ° C. for 4 hours. After drying, it is placed in a desiccator containing silica gel and allowed to cool for 1 hour at 20 ° C. and 65% RH. After measuring the weight of the sample + weighing bottle (W1), the sample is taken out and the weight (W2) of only the weighing bottle is measured. Obtain the absolute dry weight (W3) of the sample.
W3 = W1-W2

A 100% cellulose fiber sheet (S) of the same type as the result obtained in the material analysis is prepared, and the absolute dry weight (W4) is obtained by the same method.
The sample and S are allowed to stand at 20 ° C. × 65% RH for 24 hours, and the weight after moisture absorption (W5 and W6, respectively) is obtained.
S equilibrium water content S1 (%) = (W6−W4) / W4 × 100
Equilibrium moisture content of sample S2 (%) = (W5−W3) / W3 × 100
The weight percentage of cellulose in the sample is obtained by the following formula.
% By weight of cellulose = S2 / S1 × 100

(2) Fiber ratio of fiber diameter 2.9 to 7.1 μm Measured and calculated by the method described above.
(3) Fiber arrangement coefficient It measured and calculated by the above-mentioned method.
(4) Morphological stability when wet It was measured by the method described above.
(5) White coefficient It measured by the above-mentioned method.

(6) Dropping fiber The sample is immersed in 300 ml of pure water, subjected to ultrasonic waves for 15 minutes, and then the wiper is taken out. This liquid is filtered using a filter paper colored in black, and the fallen matter from the fiber-like wiper remaining on the filter paper is subjected to sensory determination.
Judgment level ○: There is almost no lint on the black filter paper. △: Remaining lint on the black filter paper is conspicuous. ×: Remaining lint so that the color of the black filter paper disappears.

(7) Basis weight and thickness of base material A sample is taken from an arbitrary location of the base material for the wet wiping member and hung for 72 hours under the condition of 20 ° C. × 65% RH, and the basis weight of the base material dried and conditioned The thickness was measured by the method described in JIS-L-1096.
(8) Physical irritation Measured by the method described above.

(9) Wiping property A general bacterial (SCD) agar medium (product number PL6201R010) for palm stamp check manufactured by Nikken Biomedical Research Institute, Inc. is prepared. A wet wiping member for testing is prepared by applying 250% by weight of pure water to the wet wiping member substrate. After touching the desk or the like, rub both hands 30 times or more to make the common germs in the palms of both hands as uniform as possible. The left hand is brought into close contact with the surface of the medium to transcribe common palm germs. Next, hold the wet wiping member with your left hand and wipe your right palm for 30 seconds. After wiping, the right hand is brought into close contact with the surface of the culture medium, and general germs on the palm are transferred. The medium is cultured at 37 ° C. for 1 to 2 days, and the degree of propagation of general bacteria is scored as follows using a simple judgment table of palm stamp check.
5: Cleanliness 4: Mild contamination 2: Contamination 1: Severe contamination If the left hand is 4 or more, the initial contamination level was low, and a retest is performed. The measurement was repeated 5 times, and the average value of (right hand score) − (left hand score) was defined as the wiping property.

(10) Handling property Sensory evaluation was carried out according to the following criteria for handling property when carrying out the wiping property of (9).
5: Good handleability 3: Normal handleability 1: Bad handleability

[Example 1]
Cotton linters were dissolved in a copper ammonia solution to prepare a spinning dope. The stock solution was extruded from a rectangular spinneret having a stock solution discharge hole diameter of 0.3 mm and 180 pieces / cm ² . The extruded stock solution enters the rectangular one-stage funnel together with the spinning water and is stretched at the same time as coagulation by deammonia, and the coagulated fiber is sprinkled down on the mesh-structured net, allowing the net to be perpendicular to the net traveling direction. Vibrated. Four layers of webs spun under the same conditions were stacked on the obtained one-layer web, and finally a five-layer cellulose continuous long fiber web was obtained. The obtained cellulose continuous long fiber web was regenerated with dilute sulfuric acid, washed with water, and the obtained regenerated cellulose continuous long fiber web was entangled with high-pressure water stream, followed by drying with hot air at 100 ° C. A regenerated cellulose continuous long fiber nonwoven fabric formed on the surface was obtained.

The obtained regenerated cellulose continuous long-fiber nonwoven fabric has a basis weight of 37.9 g / m ² , a thickness of 0.30 mm, and the number ratio of fibers having a fiber diameter of 2.9 to 7.1 μm constituting the nonwoven fabric surface is 100%. The fiber arrangement coefficient was 0.85. Table 1 shows the evaluation results of characteristics and functionality.
As can be seen from the table, the obtained regenerated cellulose continuous long fiber nonwoven fabric has good wiping properties, is white without bleaching, has excellent shape retention when wet, has good touch, and has low physical irritation, It was a very good non-woven fabric as a base material for a wet wiping member.

[Example 2]
In the method described in Japanese Translation of PCT International Publication No. 2002-521585, the diameter of the stock solution discharge hole is set to 30 μm, the other conditions are appropriate, and the net is set in the direction perpendicular to the net traveling direction according to the method of Example 1. The nonwoven fabric was obtained by vibrating. The basis weight of the obtained regenerated cellulose long fiber nonwoven fabric is 29.0 g / m ² , thickness 0.22 mm, and the ratio of the number of fibers having a fiber diameter of 2.9 to 7.1 μm constituting the nonwoven fabric surface is 100%. The fiber arrangement coefficient was 0.90. Table 1 shows the evaluation results of characteristics and functionality.
As can be seen from the table, the obtained purified cellulose long fiber nonwoven fabric has good wiping properties, is white without bleaching, has excellent shape retention when wet, has good touch, has low physical irritation, and is wet. It was a very good nonwoven fabric as a substrate for a wiping member.

[Example 3]
A regenerated cellulose continuous long fiber nonwoven fabric was obtained in the same manner as in Example 1 except that the discharge amount of the stock solution was reduced. The obtained regenerated cellulose continuous long-fiber nonwoven fabric has a basis weight of 22.0 g / m ² and a thickness of 0.14 mm, and the ratio of the number of fibers having a fiber diameter of 2.9 to 7.1 μm constituting the nonwoven fabric surface is 100%. The fiber arrangement coefficient was 0.85.
The obtained regenerated cellulose continuous long-fiber nonwoven fabric and a polypropylene spunbond nonwoven fabric (product number PC8045, basis weight 44.5 g / m ² , thickness 0.47 mm) manufactured by Asahi Kasei Fiber Co., Ltd. A composite nonwoven fabric was obtained.
The obtained composite nonwoven fabric has a basis weight of 67.0 g / m ² and a thickness of 0.52 mm. The number ratio of fibers having a fiber diameter of 2.9 to 7.1 μm constituting the nonwoven fabric surface is 65%, and the regenerated cellulose continuous The fiber arrangement coefficient on the long fiber nonwoven fabric surface was 0.65. Table 1 shows the evaluation results of characteristics and functionality.
As can be seen from the table, the obtained composite nonwoven fabric has good wiping properties, is white without bleaching, has excellent shape retention when wet, has good touch, has low physical irritation, and has liquid retention. Although there were some difficulties, it was a very good non-woven fabric as a base material for a wet wiping member.

[Comparative Example 1]
In Example 1, a regenerated cellulose continuous long-fiber nonwoven fabric was obtained in the same manner as in Example 1 except that the number of vibrations of the net on which the web was shaken off was reduced. The obtained regenerated cellulose continuous long-fiber non-woven fabric is 100% in terms of the number ratio of fibers having a basis weight of 38.2 g / m ² , a thickness of 0.31 mm, and a fiber diameter of 2.9 to 7.1 μm constituting the non-woven fabric surface. The arrangement coefficient was 0.55. Table 1 shows the evaluation results of characteristics and functionality.
As can be seen from the table, the obtained wet wiping base material had a problem as a wet wiping base material because tearing occurred in a direction parallel to the MD direction with a slight force during wiping.

[Comparative Example 2]
Example 1 is the same as Example 1 except that the diameter of the stock solution discharge hole is 0.3 mm and a rectangular spinneret present at 180 pieces / cm ² is used, and the number of vibrations of the net for shaking off the web is slightly reduced. The regenerated cellulose continuous long fiber nonwoven fabric was obtained by the method described above. The obtained regenerated cellulose continuous long-fiber non-woven fabric has a fiber percentage of 0%, with a basis weight of 37.7 g / m ² , a thickness of 0.35 mm, and a fiber diameter of 2.9 to 7.1 μm constituting the non-woven fabric surface. The arrangement coefficient was 0.72. Table 1 shows the evaluation results of characteristics and functionality.
As can be seen from the table, the obtained wet wiping substrate was inferior in wiping property as compared with the wet wiping substrate of the present invention.

  According to the present invention, a substrate for a wet wiping member having excellent shape retention properties when wet, water or chemical solution retention properties, good wiping properties, and low physical irritation to the human body and instruments, and A wet wiping member can be obtained.

It is a figure which shows typically the measuring method of a fiber arrangement coefficient and a diffusion area. It is a figure which shows typically the measuring method of a wet form retention rate.

Explanation of symbols

1 ... Stand 2 ... Sample holding plate (A sample is fixed between two sheets)
3 ... Sample 4 ... Load

Claims (4)

  At least one surface is a nonwoven fabric in which cellulose long fibers having a fiber diameter of 2.9 to 7.1 μm occupy 60% or more of the number of fibers, and the fiber arrangement coefficient on the surface is 0.65 to 1.35. A base material for a wet wiping member.   The base material for wet wiping members according to claim 1, wherein the nonwoven fabric contains 30% by weight or more of cellulose long fibers.   The substrate for a wet wiping member according to claim 1 or 2, wherein the cellulose long fibers are regenerated cellulose continuous long fibers.   The wet wiping member formed by impregnating the base material for wet wiping members in any one of Claims 1-3 with water and / or a chemical | medical solution.

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