JPH09313418A - Wiping sheet and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wiping sheet which is tough and lintfree and shows a good performance of dust attachment, with which dust and dirt can be removed easily. SOLUTION: An acrylic non-woven cloth of wet type is formed from a number of acrylic ultra-thin fibers of 20mm long or less having the maximum section diameter between 0.5-3μm, in which the fibers are dispersive in some area while joined in a single body in other area, and short fibers whose single yarn diameters range from 7 to 20μm and ratio L/D lies in the range 0.5×10<3> thru 2.0×10<3> , where L represents the fiber length and D the diameter. The ratio by weight of the acrylic ultra-fine fibers to staple fibers in this non-woven cloth ranges from 10:90 to 90:10, and the two sorts of fibers are entangled with one another and consolidated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multipurpose wiping sheet that uses an acrylic fiber non-woven fabric, from industrial to commercial and domestic use, and is capable of removing a wide range of stains from fine dust to large cotton dust. The present invention relates to a wiping sheet.

[0002]

2. Description of the Related Art With recent changes in living environment and sophistication of industrial activities, there is an increasing demand for removal of dirt. The dirt includes the adhesion of an aqueous or oily liquid and the adhesion of solid particles on the solid surface, and in particular, the solid particles have a wide range from very fine dust / dust to hair, cotton dust and bread crumbs. Various wiping sheets have been proposed and sold in order to remove these stains.

Acrylic fiber non-woven fabrics have been conventionally known. Recently, attention has been paid to a non-woven fabric made of acrylic fiber having a special fiber structure (Japanese Patent Laid-Open No. 2-200857). The fiber described in JP-A-2-200857 has a large number of openings of unspecified shape in the cross section of the fiber, and each of the openings is inside the fiber and extends along the length direction of the fiber. The non-woven fabric made of acrylic fiber forms a substantially parallel line-shaped void (straw shape) having a length of 60 μm or more. It is noted for its excellent stain removal effect brought about by the special structure of the fiber. There is.

However, although this nonwoven fabric forms a fiber layer in which fine fibers divided on the surface are intertwined with each other, the fine fibers have a very small diameter and are difficult to move by a high-pressure water flow. The degree of entanglement between them was not sufficient, and they were not always satisfactory in terms of surface abrasion resistance of the nonwoven fabric and fiber loss. Furthermore, a wet type non-woven fabric composed of only the entangled fine fibers (Japanese Patent Laid-Open No. 4-1
(Japanese Patent No. 85793) has also been devised, but the fact is that it is not possible to obtain a wiper that is lint-free and has good stain removal performance, such as the fact that the fibers tend to fall off due to the shorter fiber length. Furthermore, it has been difficult to remove large dust such as cotton dust and bread crumbs from the non-woven fabric made of the acrylic fiber. Therefore, when trying to apply the acrylic non-woven fabric to the fields of industrial wiping cloth, flooring wiper, etc., it is possible to improve the dropping performance of fibers and the lint-free performance and the dusting performance against large dust such as cotton dust and bread crumbs. Is desired.

Therefore, as a measure for improving the tensile strength, abrasion resistance, and durability of the nonwoven fabric, a method has been proposed in which the acrylic fine fibers are integrally bonded by fusion of heat-fusible fibers ( JP-A-5-295644). However, since the non-woven fabric structure of this non-woven fabric is fixed to the hot-melt fibers, the fibers do not fall off and the strength and durability have been improved, but the non-woven fabric has a hard texture due to fusion between the fibers. , Because the degree of freedom of ultrafine fibers decreases,
Although it is excellent in adsorbing liquid dirt and fine dust, it has a problem that dirt of large solid particles such as hair, cotton dust, and bread dust is poor in dust absorption.

On the other hand, in Japanese Patent Laid-Open No. 4-96724, by mixing ultrafine fibers and ordinary fibers, large dusts such as hair, thread waste, and cotton dust which cannot be collected by the ultrafine fiber sheet are caught to wipe off the fibers. An improved cleaning article has been proposed. Further, in JP-A-2-124122 and JP-A-7-184815, it is possible to improve the dust collecting performance by the fibers having a high degree of freedom on the sheet surface by providing naps on the surface of the fabric or achieving very weak fiber entanglement. Ingenuity is proposed. Further, in Japanese Patent Laid-Open No. 5-192285, by supporting a drug on a fiber assembly entangled with a mesh sheet, the drug has an increased ability to adsorb dirt such as fine dust, and unevenness caused by the mesh sheet. A cleaning article that is excellent in collecting cotton dust, yarn waste, hair, bread waste, etc. has been proposed due to the entanglement effect of the highly flexible non-woven fibers.

However, the former cleaning article in which the ultrafine fibers and the ordinary fibers are mixed and which is not provided with the chemical, is entangled with a relatively long short fiber web formed by a dry card machine, as is clear from the examples. Since it is made of non-woven fabric, it is not enough to absorb both very fine dust and large cotton dust and bread crumbs. That is, if the ratio of the ultrafine fibers is increased, fine dust is captured, but the adsorptivity of large cotton dust decreases. On the contrary, when the ratio of the normal fibers is increased, there is a problem that the adsorption of fine dust is extremely reduced. JP-A-2-1241
22, JP-A-5-192285, there is a problem that the manufacturing process is complicated and the productivity is low because it is a cleaning article composed of a special mesh sheet and a fiber web aggregate. Since it is a entangled nonwoven fabric,
Large dust is entangled and adsorbed with free non-woven fibers,
Very poor dust / dust absorption. As an improvement, a device for carrying a drug has been devised, but application of a large amount of the drug gives a sticky feeling to the sheet and is not preferable. For the purpose of improving the stickiness and the migration of the drug, in the article disclosed in JP-A-59-140282, a low-melting wax and a liquid lubricating oil are used as cleaning fibers in a weight ratio of 1: 5 to 5: 1. It is devised to give. It is necessary to increase the amount of chemicals adhering to improve the dusting property of cleaning fibers such as dust / dust, and as a result, the sticky feeling deteriorates. It becomes necessary to increase the amount (for example, 50% by weight), and it is difficult to improve both the dusting property and the sticky feeling, and there are drawbacks such as a stiff and hard texture, and a sticky feeling remains.

[0008]

SUMMARY OF THE INVENTION The object of the present invention is to maximize the soil removal performance of the non-woven fabric disclosed in Japanese Patent Laid-Open Publication No. 2-200857, and to obtain the tensile strength, the tear strength and the surface. An excellent wiping sheet for clean rooms with improved wear strength, lint-free performance with less fiber loss, and a wide range of adsorption performance from very fine dust / dust to hair, cotton dust and bread crumbs. The present invention is to provide an acrylic wet non-woven fabric that can be used in a wide range of fields from home-use and commercial flooring sheets.

[0009]

That is, the present invention is 0.5
Acrylic ultrafine fibers with a longest cross-sectional diameter of ~ 3μm and a fiber length of 20mm or less. The diameters of a large number of fibers and single yarns that are dispersed and spread at a certain part and are joined at a certain part are 7 to 20μm. And the ratio of the fiber length L to the fiber diameter D L /
D is 0.5 × 10 ^{3 to} 2.0 × 10 ³ and is composed of short fibers, and the weight ratio of the fibers is acrylic ultrafine fibers: short fibers = 10 to 90:90 to 10 which are entangled and integrated. A wiping sheet comprising an acrylic wet non-woven fabric, wherein the acrylic wet non-woven fabric holds a drug in an amount of 1 to 30 wt% of the weight of the non-woven fabric. is there.

Further, the fiber having a length of 20 mm or less has a large number of openings having an unspecified shape in its cross section, and each of the openings has a diameter of 60 μm which is substantially parallel to the inside of the fiber along the length direction of the fiber. The diameter of the acrylic synthetic fiber (hereinafter abbreviated as fibril) forming a streak (straw-shaped) void having the above length and the single yarn is 7 to 20 μm, and the ratio of the fiber length L and the fiber diameter D is L / A short fiber having D of 0.5 × 10 ^{3 to} 2.0 × 10 ³ in a weight ratio of acrylic synthetic fiber: short fiber = 5
After obtaining a mixed paper sheet of 95:95 to 5, high-pressure water is jetted from a nozzle, and the fibrils and short fibers are entangled to finely divide the fibrils one by one, and entangle them to obtain a wet non-woven fabric,
A method for producing a wiping sheet, characterized in that the chemical is held in an amount of 1 to 30% by weight based on the weight of the nonwoven fabric.

The wiping sheet made of the wet nonwoven fabric of the present invention comprises acrylic ultrafine fibers having a special shape [hereinafter referred to as fiber (1)] and short fibers having a specific L / D [hereinafter referred to as fiber (2)]. It is necessary that the fibers are intricately entwined and integrated with each other, and it is only with this structure that excellent mechanical properties and lint-free performance with less fiber loss and very fine dust / dust to hair, cotton, etc. Exhibits a wide range of adsorption performance for dust and bread crumbs.

The wiping sheet of the present invention will be described in more detail below. FIG. 1 is a longitudinal sectional view of a fiber (1) used for producing the acrylic fiber nonwoven fabric of the present invention,
And FIG. 2 is an electron micrograph (magnification of 4000 times) showing the structure of the cross section of the fiber (1). 1 and 2
In, the black portion indicates the presence of voids. As can be seen from FIG. 1, the fiber (1) has a large number of openings of unspecified shape in its cross section. The large number of openings of unspecified shape present in the cross section of the fiber (1) enables the fiber (1) to be easily split (teared) in the length direction of the fiber, and the size of the opening The size (pore diameter) is not particularly limited as long as the conditions described below are satisfied.

A large number of fine openings are preferable in that the fiber (1) can be easily divided and fine tear fibers can be obtained.
Further, even if there is an opening having a large pore size, if there is an opening having a small pore size around it, the fiber (1) is easily divided to form a fibril. As shown in FIG. 2, each of these openings is formed in the inside of the fiber (1) as a streak-like void (straw shape) substantially parallel to the length direction of the fiber. The length of the void along the length direction of the fiber (hereinafter referred to as the length of the void) must be long enough to easily divide the fiber (1). From this point of view, this void has a length of 6
It is preferably 0 μm or more, and if it is shorter than this, it becomes difficult to divide the fiber (1) in the longitudinal direction. If the length of the void is 60 μm or more, the longer the fiber (1) is divided,
Most preferably, it is substantially continuous over the entire length of the fiber (1).

The numerical aperture in the cross section of the fiber (1) is preferably as large as possible so that the fiber (1) can be easily divided. The number of openings in the cross section of the fiber (1) is not uniformly determined in relation to the length of the voids in this opening, but 10
It is preferable that there are 0 or more. If it is less than this, it becomes difficult to divide the fiber (1) even if the void has a continuous opening of 60 μm or more. If there are 100 or more voids in the cross section of the fiber (1), the more the voids, the easier the division of the fiber (1) and the easier the formation of fine fibers. Further, it is preferable that the voids are evenly distributed in the cross section of the fiber (1) in order to facilitate the division of the fiber (1).

As used in the present invention, a large number of fibers dispersed and spread in a certain part and joined and integrated in a certain part means a columnar shape in the process of manufacturing the fiber (1) into a nonwoven fabric. It is easily divided into fine fibers by flow punching, and the fine fibers are randomly dispersed in a three-dimensional manner in some areas, and in some areas, the divided fine fibers are converged and integrated. Or a large number of fibers in a state in which the fine fibers are integrated in a state of being undivided or partially divided and still having a large number of voids inside the fiber.

The fine fibers at least a part of which are used in the present invention are those finely divided into fine fibers by columnar flow punching in the step of producing the fiber (1) into a nonwoven fabric. Say. Furthermore, the fiber (2), which is the other constituent yarn of the present invention, has a single yarn diameter of 7 to 20 μm.
The ratio L / D of the fiber length L and the fiber diameter D in m is 0.5 × 10
It is necessary to satisfy both of the two factors of ^{3 to} 2.0 × 10 ³ . In the case of an ultrafine fiber having a diameter of a single yarn of less than 7 μm, the strength of the single yarn is too low, so that the abrasion resistance,
Improvements in delamination strength and the like are not sufficiently achieved, and fiber loss (lint) generated from acrylic ultrafine fibers cannot be sufficiently suppressed. On the other hand, in the case of a fiber having a large fiber diameter of more than 20 μm, the dense entanglement with the acrylic ultrafine fiber becomes insufficient, and similarly, it is possible to obtain the effects of improving the strength physical properties and abrasion resistance and preventing the fiber waste from falling off. Can not. The preferable range of the diameter of the single yarn of the short fibers capable of maximizing the effect of the present invention is 7 to 15 μm. Next, the fiber (2) needs to have an L / D in the range of 0.5 × 10 ^{3 to} 2.0 × 10 ³ . The preferable range is 0.5 × 10 ³ to 1.
It is 5 × 10 ³ . It was found by the study of the present inventors that the L / D of the single yarn has an important relationship with the ease of entanglement of the fibers with each other by high-pressure water, and when the L / D is less than 0.5 × 10 ³ , And 2.0 × 10 ^{3 or more} , the strength of the target wet non-woven fabric, abrasion resistance and delamination strength, and fiber loss from the wet non-woven fabric caused by the special acrylic ultrafine fibers of the present invention ( Lint) is not suppressed, and the effect of securing sufficient lint-free performance cannot be obtained. This surprising fact is estimated as follows.

That is, the smaller the L / D easiness of movement of the fibers due to the columnar flowing water flow, that is, the thicker and shorter the easiness is, the larger the entanglement between fibers becomes. On the other hand, the number of contact points between fibers increases as the fibers become thin and long, that is, L / D increases. However, if L / D is too large, the movement of the fibers at the time of entanglement is suppressed, and the entanglement between the fibers is decreased. Therefore, there is an optimum range of L / D that maximizes the entanglement density between fibers, and this range is 0.8 × 10 ³ to
It is understood to be 2.0 × 10 ³ . However, in order not to impair the sheet uniformity of the wet non-woven fabric, the fiber length is preferably 20 mm or less even if the L / D of the fiber (2) is within the proper range of the present invention, while the columnar flow punching is easy. Therefore, the fiber length is preferably at least 5 mm or more.

As described above, by adopting the fibers under the condition that the entanglement density is maximum, the fallen fibers generated by slipping or breaking of the acrylic fine fibers of the fibers (1) are suppressed, and the fibers (2 ) Results in a firmer grip,
Excellent lint-free performance and surface abrasion strength are exhibited for the first time in a wet non-woven fabric made of ultrafine fibers. The content of the fiber (1) and the fiber (2) in the wiping sheet of the present invention can be selected in the range of 5 to 95:95 to 5 by weight ratio, preferably 10 to 90:90 to 10, and more preferably Is 20-80: 80-20. If the content of the fiber (2) is less than 5% by weight, the above effect is not exerted, and 95
When the content is more than 10% by weight, even if the fiber (1) has a very high dirt / dust removing performance, the dust removing performance deteriorates. It is desirable that these fibers (1) and fibers (2) constituting the acrylic wet non-woven fabric are uniformly mixed.

The diameter of the single yarn of the fiber (2) of the present invention may be a circular cross-section of the single yarn or various non-circular modified cross-sections. In the case of a circular shape, the diameter of the single yarn is determined by directly measuring the diameter, and in the case of a modified cross-section yarn, the diameter of the single yarn is measured by the weight method to determine its fineness (denier).
This denier is represented by the average diameter calculated by the following formula (1) when the single yarn is assumed to be circular.

[0020]

[Equation 1]

The fibers constituting the fiber (2) of the present invention include polyester fibers such as polyethylene terephthalate and polybutylene terephthalate, polyamide fibers such as nylon 6, nylon 66 and 610, polyvinyl alcohol fibers, polyethylene and polypropylene. Polyolefin fiber, acrylic fiber, cellulosic fiber (Bemberg, rayon) and the like can be used.

The wet acrylic non-woven fabric of the present invention has a chemical content of 1 to 30% by weight based on the weight of the non-woven fabric.
It has been found that the performance of absorbing large dust such as cotton dust is improved without deteriorating the dust-adhering property of fine dust such as dust / dust originally possessed by the fiber (1). A more preferable range of the attached amount is 3 to 20% by weight, and further preferably 5 to 1
5% by weight. When the amount of adhesion is 1% by weight or less, the effect of holding the drug is not remarkably exhibited. On the other hand, when the amount of adhesion exceeds 30%, the excellent wiping performance due to the special fiber structure of the present invention or the dusting property of hair due to static electricity is extremely deteriorated, or sticky feeling is generated, and it moves to the floor, etc. This is not preferable because it causes the disadvantage of

The type of drug has a viscosity of 1 at 25 ° C.
It is preferable to attach 1 to 30% of a highly viscous drug having a viscosity of more than 000 centistokes (hereinafter referred to as cst), and a well-balanced high dust absorption performance and a long-lasting durability against a wide range of dust from hair, dust / dust to cotton dust Is obtained. This means that the acrylic fiber constituting the wet nonwoven fabric of the present invention has a large number of openings having an unspecified shape in the cross section of the fiber, and each of the openings extends inside the fiber along the length direction of the fiber. Since it is composed of acrylic synthetic fibers forming a linear (straw-shaped) void having a length of 60 μm or more substantially parallel to each other, and fine fibers divided from the acrylic synthetic fiber, the attached drug has a void portion of the fiber or a capillary phenomenon. It is considered that the peculiar phenomenon that the permeation into the inner layer voids occurs and the amount of the oil agent adhering to the fiber surface decreases with time is suppressed and improved by adhering the agent having a specific viscosity. As the type of drug, synthetic oil such as liquid paraffin, mineral oil, silicone oil, alkylbenzene oil or vegetable oil such as castor oil, olive oil and camellia oil can be applied, or dimethyl silicone oil having a viscosity of 1000 cst or more at 25 ° C, various modified silicones. Oils and the like and mixtures thereof are preferably used. Surfactants, preservatives and antioxidants may be added to these agents. Further, it has been found that a mixed drug of wax and liquid paraffin can be most preferably used as a drug to be applied to the acrylic wet non-woven fabric of the present invention.
In this case, the mixing weight ratio of wax and liquid paraffin is 1 to 40:99 to 60. Preferably 1 to 30:
It is 99 to 70, and more preferably 1 to 15:99 to 85. When the weight% of wax exceeds 40, the fluidity of the chemical agent on the fiber surface is poor, and conversely, the ability to remove fine dirt such as dust originally possessed by the fine fibers of the fiber (1) deteriorates. However, there is a problem that the dusting property of the hair is deteriorated, which is not preferable, and the texture of the sheet becomes hard.
On the other hand, if it is less than 1% by weight, the amount of wax is small, and the effect of improving the dusting property due to the synergistic effect of the liquid paraffin and the wax on the fiber surface and its continuous durability cannot be expected.

As the type of wax, natural waxes such as petroleum wax, mineral wax, animal wax and plant wax, and synthetic wax can be used, but petroleum wax is preferable from the viewpoint of handleability. Petroleum wax has a melting point of 37 to 76 ° C due to the difference in melting point and molecular weight.
"Paraffin wax" whose main component is n-paraffin having a molecular weight of 300 to 500 and a carbon number of 20 to 36, and a melting point of 60.
It can be classified into "microcrystalline wax" containing isoparaffin having a molecular weight of 450 to 700 and a molecular weight of 450 to 700 as a main component, and can be appropriately selected from these, but refined paraffin wax has less impurities, has less offensive odor and coloration, and paraffin wax alone and It is preferably used in the present invention in combination with microcrystalline wax. When using a high melting point microcrystalline wax, excellent effects are exhibited even with a small mixing ratio with liquid paraffin. For example, when a microcrystalline wax having a temperature of 86 ° C. or higher is mixed with liquid paraffin, an excellent effect is exhibited when the ratio of the microcrystalline wax is 1 to 10% by weight, preferably 1 to 5% by weight. Mixing and adding wax to liquid paraffin increases the viscosity of the composition liquid, and the chemicals adhering to the surface of the constituent fibers are retained over time without migrating to the numerous voids inside the nonwoven fabric, and durability is improved. We have found that it can be dramatically improved.

Next, a method for producing the acrylic fiber wet non-woven fabric of the present invention will be described. The fiber (1) used in the present invention contains 60% by weight of acrylonitrile (hereinafter abbreviated as AN).
A fiber made of an acrylic polymer containing the above. This polymer may be a mixture of two or more acrylic polymers. This acrylic polymer is its solvent, for example,
It is dissolved in dimethylformamide, dimethylacetamide, dimethylsulfoxide, concentrated aqueous solution of rhodanate, concentrated aqueous solution of zinc chloride, and aqueous nitric acid solution to prepare a spinning dope. The optimum concentration of the polymer in the spinning dope varies depending on the solvent, but is preferably 10 to 30% by weight.

Polyalkylene glycol is added to this spinning dope. This polyalkylene glycol contains 20 to 80% by weight of ethylene oxide and 80 to propylene oxide.
It is a random or block copolymer with 20% by weight, and its number average molecular weight is 5,000 to 50,000, preferably 10,000 to 20,000. When the number average molecular weight of the polyalkylene glycol is less than 5,000, continuous voids in the length direction of the fiber cannot be obtained, and the fiber becomes a microporous fiber having very fine substantially spherical cavities.
On the other hand, when the number average molecular weight exceeds 50,000, the fiber becomes a fiber having huge streak-like voids, and moreover, the fiber has at most a dozen cavities in the cross section of the fiber. This fiber cannot be divided into fine fibers by an external force such as columnar flow punching. Number average molecular weight is 10,000
With a polyalkylene glycol of 20,000, fine fibers are obtained along the length direction of the fiber, and a fiber (1) having elongated voids with an unspecified cross-sectional shape in the cross section is obtained.

The spinning solution containing the polyalkylene glycol is then aged for at least 4 hours. This aging is to leave the spinning dope containing polyalkylene glycol added, without vigorously stirring or vibrating, for example, to leave still or gently feed the solution. The amount of polyalkylene glycol added is 5 to 20% by weight, preferably 10 to 15% by weight, based on the acrylic polymer. If the addition amount is less than 5% by weight, the number of voids in the cross section of the fiber (1) is small, and if it exceeds 20% by weight, the number of voids is too large, and the fiber (1) is divided during the production process of the fiber (1). Or stable spinning cannot be performed. When the amount added is 10 to 15% by weight, the number of voids in the cross section of the fiber (1), the stability of spinning, etc. are most balanced.

The spinning stock solution containing polyalkylene glycol is extruded through the spinneret into the coagulating liquid,
After obtaining the steps of washing with water, stretching, drying, etc., heat treatment is carried out if necessary. The polyalkylene glycol added to the spinning dope is eluted from the coagulated filamentous material in the steps such as coagulation, stretching and washing with water. The acrylic fiber of the fiber (1) thus obtained is cut to a fiber length of 20 mm or less. Considering the ease of hydroentanglement, the preferable range of cutting is L of fibrils.
/ D is preferably 0.5 × 10 ^{3 to} 2.0 × 10 ³ . Assuming that the diameter (D) of the fiber (1) having an elongated void with an unspecified cross-sectional shape in the cross section, the fiber (1)
The denier is preferably 1 to 3 denier in view of its spinning stability and void forming property, and is 10 in terms of the diameter D.
˜20 μm is preferred. At this time, it can be said that the fiber length of the fiber (1) is preferably 5 to 20 mm in order to obtain the L / D of the raw yarn within the above range. Acrylic fibers and short fibers (fibers (2)) cut to a length such that L / D falls within the above range are mixed in water at a predetermined ratio to form a slurry, and a wet sheet is formed by a papermaking method. Next, this fiber sheet is supported on a net or roller, and a columnar flow of high-pressure water is jetted to this fiber sheet (hereinafter referred to as columnar flow punching) to separate the fibers (1) from each other while dividing them. Confounding takes place. By this columnar flow punching, the fibers (1) and the fine fibers in which at least a part thereof are divided, and further, the fibers (1) and the fine fibers in which at least a part thereof are divided and the fibers (2) are entangled, As a whole, a wet non-woven fabric is formed in which all fibers are integrally bonded. The columnar flow punching may be performed on only one side of the fiber sheet, but it is preferable to perform the columnar flow punching from both sides in terms of strong fiber entanglement. The columnar flow punching is performed several to ten or more times depending on the entanglement of fibers or the division of fibers (1), and at least the surface of the fiber sheet achieves sufficient entanglement of the divided fine fibers and short fibers. High pressure water is 20kg / cm
A pressure of ² or more is required, and if it is lower than this, it becomes difficult to divide the fiber (1), and at the same time the fibers are less entangled with each other, and sufficient mechanical strength such as tensile strength and tear strength cannot be obtained. However, it is impossible to sufficiently suppress the fibers from falling off. The nozzle for injecting high-pressure water is appropriately selected depending on the target surface morphology of the nonwoven fabric, the divided state of the fibers (1) or the fibril forming state. When the nozzle diameter is small and the water pressure is low, the fiber (1) is split at the surface layer of the wet non-woven fabric, and when the nozzle diameter is large to some extent and the water pressure is high, the fiber (1) is split and the fibers are entangled with each other. proceed. After performing columnar flow punching, the nonwoven is dried. This dryer is a pin tenter dryer or a drum dryer.

The basis weight of the non-woven fabric is 10 g / m ² or more. If it is less than this, sufficient strength and wiping performance as a wiping sheet cannot be exhibited. The non-woven fabric obtained in this manner has excellent lint-free performance and wiping performance as a wiping cloth, dust-carrying performance, and can be suitably used as an industrial wiper and a commercial floor wiper for industrial use. 1 to 1 of non-woven fabric weight
Suitable as an excellent flooring sheet that adsorbs all kinds of dust from fine dust to large cotton dust and bread crumbs by post-processing such as holding about 30% of chemicals and raising the surface of non-woven fabric. Can be used.

As the method of applying the chemical to the non-woven fabric, a method of adjusting and impregnating a predetermined chemical, a method of spraying on the surface,
And a coating method using a gravure roll or the like can be appropriately selected. The adhered amount is 1 to 30% by weight, and 30
When applied in an amount of more than 5% by weight, a sticky feeling is felt when touched by a hand, and problems such as transfer of the drug to the surface of the article to be wiped occur. Further, as a method for raising the surface of the nonwoven fabric, buffing treatment with emery paper, brushing treatment with various brushes such as metal, plastic such as PVC, brushing treatment with raised brush such as pig hair, and conventional methods such as MC roll can be appropriately selected. This raising treatment can obtain the effect according to the purpose even if only one side is used, but it is preferable to treat both sides, for example, when both sides are used as flooring wipers. This raising treatment may be carried out in a step before or after the above-mentioned chemical application,
For example, if a chemical is applied after the nap treatment, problems such as floating shavings floating in the chemical bath may occur in the process. Therefore, it is preferable to perform the nap treatment after the chemical treatment.

[0031]

The present invention will be described below in more detail with reference to examples. The tensile strength, tear strength, and surface abrasion resistance of the nonwoven fabric were evaluated according to JIS L-1096 and Martindale abrasion test. In addition, the wiping performance was evaluated by the following methods. (1) Lint-free property: Particle counter (made by RION, K that can measure the particle size range of 0.3 to 5 μm)
The generated lint of the test piece (10 × 10 cm) was measured using C-01A) and expressed as the total number of lint of 0.3 to 5 μm. (2) Washing resistance: 1 to 10 test pieces of 15 cm x 15 cm containing 40 g of detergent (new beads; Kao) at room temperature 30
household washing machine (Toshiba, Galaxy VH-101
5) Strong wash 5 minutes, dehydration 1 minute, water wash 15 minutes, dehydration 1
Washing is repeated with 1 minute as one cycle. The appearance change of the sample is observed every cycle. Classify by the number of cycles in which a noticeable change in appearance (a noticeable fluff, tear, or deformation) is recognized. The ones that cause a noticeable change in appearance in one cycle are grade 1, and those that are 15 cycles or more are grade 5,
Rank between 1st and 5th grade. (3) Wipeability (water-based, oil-based): A drop of ink (water-based) or oil-based ink (oil-based) was dropped on a glass plate, and after wiping once with a test piece (2 x 30 cm), it was wiped on the glass plate. The residual amount of the black liquor was evaluated with a colorimeter to determine the ΔE value.
The larger the ΔE value is, the larger the residual amount is. The values are 0 to 1 in the 5th grade, 15 in the 4th grade, 30 in the 3rd grade, 45 in the 2nd grade,
Aqueous stains and oily stains were evaluated on the basis of 60 or more as the first grade. (4) Lost fiber measurement method: Tatami edge cloth (Tamaji, pure cotton, koge tea)
To the plate. Test piece (20 x 30 cm) on the mop jig
Attach it, place it on the tatami edge cloth, and place 50 on the jig.
Place 0g weight and pull it back and forth 3 times. Place a 5 cm square frame on the tatami-bed cloth where the most of the fibers have fallen off, and count the fiber scraps of 3 mm or more in the frame. (5) Hair collection ability: 3000 10 hairs 10 cm in length
Disperse as evenly as possible on a cm ² (30 × 100 cm) wooden floor test plate (Okura Industry, composite type flooring 589 Nara random scale). Similar to the falling fiber test method, the test piece is reciprocated from end to end of the test plate three times, and then shaken lightly three times in order to remove hair that has not been sufficiently collected. Count the number of hairs attached to the sample. Repeat 10 times and calculate the average value. (6) Dust collecting ability: 0.5 g of the test dust is sprayed on the wooden floor test plate in the same manner as in the hair collecting ability measurement, and the test piece is wiped off in the same manner, and the weight of the dust attached to the sample is measured. 3
Repeat and calculate the average value. (7) Cotton linter collection ability: Measured in the same manner as dust collection ability using a test cotton linter, and expressed by the linter weight collected in the sample. (8) Evaluation of continuous durability: The results of the evaluation of hair collection performance, dust collection performance, and cotton linter collection performance after the chemical application, and the evaluation results after 6 months and the evaluation results after the chemical application. The difference is indicated by ⊚ to × (⊚ indicates almost no difference in the evaluation results, × indicates a level significantly reduced from the initial wiping performance, and ○ and Δ are intermediate levels). (9) Dry sensation: ◎ when a non-woven fabric is touched by human hands and it feels dry, and ◎ when it feels damp.
Was evaluated, and the intermediate feeling was evaluated as ◯ and Δ. Example 1 Copolymer of 95.0% by weight of AN, 4.5% by weight of methyl acrylate and 0.5% by weight of sodium methallyl sulfonate, polyethylene oxide-polypropylene oxide-polyethylene oxide block type polyether (number The average molecular weight is 100,000, and the weight ratio of polyethylene oxide and polypropylene oxide is 70: 3.
0) is dissolved in dimethylformamide to give an acrylic polymer 23% by weight and a block type polyether 2.3% by weight.
A spinning stock solution containing was prepared. After leaving this spinning dope for 6 hours, it was extruded through a spinneret into a coagulation bath at a temperature of 35 ° C. and 75% by weight of dimethylformamide, and after washing with water,
It was stretched 12 times in boiling water and dried in hot air at 80 ° C. to produce 1.5 denier fiber [fiber (1)]. Electron micrographs (magnification: 4000 times) showing the structures of the longitudinal section and the transverse section of this fiber (1) are shown in FIGS. 1 and 2.

Fiber (1) cut to a length of 12 mm and 1.
Short fibers (fiber (2): L / D = 1000) obtained by cutting 0 denier polyester fiber to a length of 10 mm and 7
A fibrous sheet having a basis weight of 50 g / m ² was produced by a Fourdrinier paper machine as a uniform slurry by dispersing it in water at a weight ratio of 0:30. This paper sheet is placed on a wire mesh of 80 mesh, and water is jetted at a water pressure of 75 kg / cm ² from a 1-row nozzle having a diameter of 0.15 mm and a pitch of 0.8 mm to 20 m / min.
Columnar flow punching was performed while moving at the speed of. Next, columnar flow punching was performed from the back side of the fiber sheet under the same conditions. This operation was repeated 5 times to form a fiber entangled sheet, which was then dried with a pin tenter hot air dryer at 80 ° C.

The resulting non-woven fabric was subjected to measurement of strength physical properties and performance evaluation as a wiping sheet. As a result, excellent tensile strength not obtained by conventional wet non-woven fabric,
In addition to showing tear strength and surface abrasion resistance, it showed excellent lint-free property and excellent wiping performance against both water-based and oil-based stains (see [Table 1]).

[0034]

[Table 1]

Example 2 Copolymer of 95.0% by weight of AN, 9.5% by weight of methyl acrylate and 0.5% by weight of sodium methallyl sulfonate, polyethylene oxide and polypropylene oxide random copolymer type polyether ( The number average molecular weight is 100,000, and the weight ratio of polyethylene oxide and polypropylene oxide is 75:25).
Acrylic polymer 16 dissolved in a 7 wt% nitric acid aqueous solution
A spinning dope containing 100% by weight and 2.4% by weight of a random copolymer polyether was prepared. The spinning solution was left to stand for 6 hours, then extruded through a spinneret into a 37% by weight nitric acid aqueous solution cooled to 0 ° C., washed with water, and then in boiling water for 9.5.
The fiber was double-stretched, dried in hot air at 70 ° C., and passed through normal-pressure steam to produce a 1.5 denier fiber [fiber (1)].

This fiber [fiber (1)] was cut into a length of 12 mm and mixed with polyester fibers having a denier of 1.0 mm and a length of 5 mm No. 1, No. 2, No. 3, No. 4, as well as
Fibers (1): fibers (2) = 90: 10, 70:30, 50:50, 30: for No. 5 with different weight ratios, respectively.
70 and 10:90 were produced by a Fourdrinier paper machine.
All areal weights were 50 g / cm ² . These papermaking sheets were placed on a wire mesh of 80 mesh and subjected to columnar flow punching treatment under the same conditions as in Example 1 to obtain a nonwoven fabric sheet.

The respective strength physical properties and wiping performance were evaluated in the same manner as in Example 1 and shown in Table 2. It has excellent tensile strength, tear strength, and surface abrasion resistance that cannot be obtained with conventional wet-laid nonwoven fabrics, and also has a well-balanced performance in lint-free property and wipeability as a wiping cloth, making it suitable for industrial wipers, especially for clean rooms. It proved to be suitable. On the other hand, in the dustiness evaluation, the excellent dustiness of hair, dust and the like resulting from the use of the special acrylic fiber of the present invention was maintained, and it was also suitable as a floor wiper for business use and household use.

[0038]

[Table 2]

Example 3 The wet nonwoven fabric obtained in Example 1 was brushed with an etiquette brush, and then silicone oil KF96-1000 (produced by Shin-Etsu Chemical Co., Ltd.) (viscosity 10
00cst [25 ° C]) was applied to the front and back surfaces of the nonwoven fabric by a roll coater method in an amount of 15% by weight to prepare a wiping sheet for flooring. The wiping performance and the fluff shedding performance, etc. are shown in [Table 2] at the same time as that of Example 1 used in this Example, which was subjected to the raising treatment. [Example 4] In the same manner as in Example 3, Shin-Etsu Chemical (manufactured) modified amino silicone oil "KF861"; viscosity 3500 cst (25 ° C) was applied to the nap-treated product of the wet non-woven fabric of Example 1 while changing the adhesion rate. Flooring wiping sheet Nos. With 3, 9, 15, 20, 30% by weight attached.
1, 2, 3, 4, and 5 were created. The wiping performance and the fluff falling performance are shown in [Table 2]. [Example 5] Composition liquids obtained by mixing liquid paraffin (viscosity 71 cst [25 ° C]) with purified paraffin wax (melting point 42-44 ° C) in a weight ratio of 85:15 were added to the wet nonwoven fabric obtained in Example 1, respectively. Mix and change the adhesion rate with a gravure coater to obtain 3, 9, 15, 20, 30 respectively.
Weight% was applied. Then, the surface was lightly brushed with a pig hair brush to prepare flooring wiping sheets Nos. 1, 2, 3, 4, and 5. The wiping performance and the fluff shedding performance are shown in [Table 3] together with the performance evaluation of the non-woven fabric raised in the same manner as in Example 1.

[0040]

[Table 3]

Comparative Example 1 Acrylic short fibers of 1.5 denier and 12 mm in length produced in Example 1 [fiber (1)]
A sheet-making sheet having a basis weight of 50 g / m ² was obtained from a fourdrinier type machine. Then, a wet non-woven fabric made of only acrylic fibers [fiber (1)] was obtained in the same manner as in Example 1. It was difficult to say that the mechanical properties were sufficient, and the level of wash resistance was low. The lint-free performance due to the loss of fine fibers is extremely inadequate, and the dust absorption property of large cotton dust (cotton linter evaluation) is not sufficient. However, the performance of wiping off aqueous and oily liquid stains and the performance of dusting hair due to static electricity such as fine dust / dust were excellent (see [Table 1]). Comparative Example 2 1.0 denier and length 1 used in Example 1
A entangled nonwoven sheet having a basis weight of 50 g / m ² was obtained in the same manner as in Example 1 from a slurry in which only 0 mm polyester fiber was uniformly dispersed in water. The dustability and wiping performance are listed in [Table 1]. [Comparative Examples 3 and 4] The flooring sheets obtained in Example 4 and Example 5 in which the drug adhesion rate was 45% were used as Comparative Example 3 and Comparative Example 4, respectively. It is shown in Table 2] or [Table 3]. Example 6, Comparative Example 5 Liquid paraffin (viscosity 71 cst
[25 ° C.]) with purified paraffin wax (melting points 41-4
2 ° C.) composition liquids (liquid paraffin: wax = 100: 0, 5:95, 10:90,) having different mixing ratios (weight),
15:85, 30:70, 50:50), and the wet non-woven fabric obtained in Example 2 was made to adhere to the wet non-woven fabric at a constant attachment rate of 15% by weight. Sheet Nos. 1, 2, 3, 4,
5 and 6 were made. Table 4 shows the dusting performance and the fiber falling performance of the nonwoven fabric of Example 2 as well as the nonwoven fabric only subjected to the raising treatment.

[0042]

[Table 4]

Example 7 Liquid paraffin (viscosity 71 cst [25 ° C.]): paraffin wax (melting point 42-44 ° C.): crystal wax (melting point 92 ° C.) = 85:10: in the wet type nonwoven fabric manufactured in Example 2. 5, 85: 0: 1
A composition liquid of 0,85: 0: 10 (weight ratio) was prepared and adhered to both sides of the nonwoven fabric at an adhesion rate of 15% by weight as in Example 6, and a raising treatment was applied to the flooring sheet No.
No. 1, No. 2 and No. 3 were created.

The performance evaluation of this product is also shown in [Table 4].

[0045]

EFFECT OF THE INVENTION The wiping sheet of the present invention has excellent tensile strength, tear strength, abrasion resistance physical properties and lint-free performance in which the fall of acrylic fine fibers is suppressed, which cannot be obtained by the conventional wet nonwoven fabric. Not only is it extremely effective at removing not only water-based but also oil-based liquid stains, it also has a very wide range of shapes and types of dusting action, from very fine solid dust / dust to relatively large hair, cotton dust, and bread crumbs. Since it is excellent, it can be suitably used for industrial purposes, for example, as a wiper for a clean room where a high degree of cleanliness is required, and as a flooring wiper for business use and a household where adsorption performance of various dusts is required. Also, when used for flooring, it has a dry feel,
Not only is there a sense of cleanliness, but the fibers on the edge cloth of the tatami mat are also very few, so the tatami mat can be cleaned, and its excellent dusting performance is durable with little change over time. Therefore, the industrial value of the wiping sheet of the present invention is extremely large.

[Brief description of drawings]

FIG. 1 is a fiber (1) used for the wiping sheet of the present invention.
Electron micrograph showing the structure of the vertical section (magnification: 40
00 times).

FIG. 2 Fibers used in the wiping sheet of the present invention (1)
Electron micrograph showing the structure of the cross section of
00 times).

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] November 20, 1996

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction contents]

[0009]

That is, the present invention is 0.5
Acrylic ultrafine fibers with a longest cross-sectional diameter of ~ 3μm and a fiber length of 20mm or less. The diameters of a large number of fibers and single yarns that are dispersed and spread at a certain part and are joined at a certain part are 7 to 20μm. And the ratio of the fiber length L to the fiber diameter D L /
D is comprised of 0.5 × 10 ^{3 to} 2.0 × 10 ³ short fibers, and the weight ratio of the fibers is acrylic ultrafine fibers: short fibers = 5 to 95:95 to 5 which are entangled and integrated. It is a wiping sheet characterized by comprising an acrylic wet non-woven fabric, wherein the acrylic wet non-woven fabric holds a drug in an amount of 1 to 30% by weight based on the weight of the cloth.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0035

[Correction method] Change

[Correction contents]

Example 2 Copolymer of 90.0% by weight of AN, 9.5% by weight of methyl acrylate and 0.5% by weight of sodium methallyl sulfonate, polyethylene oxide and polypropylene oxide random copolymer type polyether ( The number average molecular weight is 100,000, and the weight ratio of polyethylene oxide and polypropylene oxide is 75:25).
Acrylic polymer 16 dissolved in a 7 wt% nitric acid aqueous solution
A spinning dope containing 100% by weight and 2.4% by weight of a random copolymer polyether was prepared. The spinning solution was left to stand for 6 hours, then extruded through a spinneret into a 37% by weight nitric acid aqueous solution cooled to 0 ° C., washed with water, and then in boiling water for 9.5.
The fiber was double-stretched, dried in hot air at 70 ° C., and passed through normal-pressure steam to produce a 1.5 denier fiber [fiber (1)].

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0037

[Correction method] Change

[Correction contents]

The respective strength physical properties and wiping performance evaluations were carried out in the same manner as in Example 1 and shown in [ Table 1 ]. It has excellent tensile strength, tear strength, and surface abrasion resistance that cannot be obtained with conventional wet-laid nonwoven fabrics, and also has a well-balanced performance in lint-free property and wipeability as a wiping cloth, making it suitable for industrial wipers, especially for clean rooms. It proved to be suitable. On the other hand, in the dustiness evaluation, the excellent dustiness of hair, dust and the like resulting from the use of the special acrylic fiber of the present invention was maintained, and it was also suitable as a floor wiper for business use and household use.

Claims (5)

[Claims] 1. A large number of acrylic ultrafine fibers having a longest cross-sectional diameter of 0.5 to 3 μm and a fiber length of 20 mm or less, which are dispersed and spread at a certain portion and are joined and integrated at a certain portion. The diameter of the single yarn is 7 to 20 μm, and the ratio L / D of the fiber length L and the fiber diameter D is 0.5 × 10 ^{3 to} 2.0 × 1.
It is characterized in that it comprises an acrylic wet non-woven fabric composed of short fibers of 0 ^{3 and} having a weight ratio of acrylic ultrafine fibers: short fibers = 5 to 95:95 to 5 which are entangled and integrated. Wiping sheet. 2. The wiping sheet according to claim 1, wherein the acrylic wet non-woven fabric holds a drug in an amount of 1 to 30 wt% of the weight of the non-woven fabric. 3. The wiping sheet according to claim 3, wherein the viscosity of the drug is 1000 centistokes (25 ° C.) or more. 4. The wiping sheet according to claim 3, wherein the medicine is a mixed medicine composed of 1 to 40% by weight of wax and 99 to 60% by weight of liquid paraffin. 5. A fiber having a length of 20 mm or less has a large number of openings having an unspecified shape in its cross section, and each of the openings is substantially parallel to the inside of the fiber along the length direction of the fiber.
The diameter of the acrylic synthetic fiber and the single yarn forming the streaky (straw-like) voids having a length of μm or more is 7 to 20 μm
In the following, the ratio L / D of the fiber length L and the fiber diameter D is 0.5 × 1
A mixed paper sheet in which a short fiber having a weight ratio of 0 ^{3 to} 2.0 × 10 ³ is used as an acrylic synthetic fiber: short fiber = 5 to 95:95 to 5 in a weight ratio, high-pressure water is jetted from a nozzle, and a raw fiber and A wiping sheet, characterized in that the acrylic synthetic fibers are subdivided one by one while being entangled with short fibers and entangled into a non-woven fabric, and then the drug is held in an amount of 1 to 30 wt% of the weight of the non-woven fabric. Production method.