JP3138074B2 - Hydraulic entangled nonwoven fabric having good texture and good feel and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydro-entangled nonwoven fabric which is obtained by using a web obtained by a wet papermaking method and in which fibers are entangled, has a good formation, is excellent in tactile sensation, drapability, texture, and strength. Related to manufacturing method.

[0002]

2. Description of the Related Art In recent years, nonwoven fabrics have been widely used in many fields instead of woven fabrics. Because of its low cost and high productivity, it can be used as a substitute for a conventional woven fabric, or can be used as a functional nonwoven fabric because it can impart performance that cannot be obtained with a woven fabric. Further, conventionally, the use of nonwoven fabrics in the field of paper pulp as a raw material has been actively utilized as a high-performance material by utilizing the functionality of the nonwoven fabric.

Among them, a so-called spunlace nonwoven fabric or a hydroentangled nonwoven fabric, in which fibers are three-dimensionally entangled using a high-pressure columnar water stream and have a texture like a woven fabric, has been actively developed, and many products have been put on the market. Has been done. Since the hydroentanglement (spunlace) method is one of the processing methods of the web, it is necessary to supply the web before processing. Web manufacturing methods include the card method, the dry method of the air lay method,
Melt blow method, spun bond method, wet papermaking method and the like can be mentioned.

In the card method, a fiber having a long fiber length can be used, but it is difficult to form a uniform web, and the nonwoven fabric obtained by processing with a high-pressure columnar water flow has poor formation. Spots are seen, leaving problems in the feel and texture. In the air lay method, if fibers having a long fiber length are used, the texture deteriorates, and the obtained nonwoven fabric has problems in terms of touch and texture. When the web obtained by the spunbond method is used, although the strength is large, the formation is poor, the fibers are continuously connected, the free ends of the fibers are small, and a large amount of energy is required for three-dimensional confounding. It is difficult to form a composite by mutual entanglement with another web. Further, in the above method, it is difficult to produce a web using fibers having a fiber diameter of 10 μm or less.

As a method using fibers having a fiber diameter of 7 μm or less, a melt blow method and a wet papermaking method are exemplified. Although the melt blow method enables web formation of fine fibers, it has problems of poor formation, low production speed, and high cost.

The wet papermaking method has a higher production rate than the above-mentioned method, and a plurality of fibers having different finenesses and types can be mixed at an arbitrary ratio in the same apparatus. That is, also in the form of fibers, staple shape, pulp shape, etc., the selection range is wide, and the usable fiber diameter can be used from so-called ultra-fine fibers of 7 μm or less to thick fibers, which is much better than other methods. This is the method by which the formation web is obtained. For these reasons, it is considered to be a web forming method having a very wide range of applications.

In the method disclosed in Japanese Patent Application Laid-Open No. 2-6651, the fiber diameter is 7 to 25 μm, and the ratio (L / D, aspect ratio) of the fiber diameter (D) to the fiber length (L) is 800 to 2.
A wet nonwoven fabric in which 000 short fiber webs are three-dimensionally entangled with a high-pressure columnar water stream is disclosed. This non-woven fabric
Attention has been paid to an improvement over the disadvantage of conventional wet nonwoven fabrics, which is a shortcoming in which the fiber length is short and the strength is low.

That is, the hydro-entangled non-woven fabric using the wet web having the above-mentioned aspect ratio has a large number of free cut ends of fibers, a large number of fibers which can move freely at the time of interlacing, and a large number of fibers uniformly. Are confounded, so that strength is expressed.

However, in the case of a nonwoven fabric having a fiber diameter of 7 to 25 μm, the fiber diameter is large, and the feel of the nonwoven fabric is still insufficient. In addition, it is pointed out that those using ultrafine fibers have low strength.

The following is an example using a web having ultrafine fibers. Japanese Patent Publication No. 2-35062 discloses a nonwoven fabric in which a plurality of short fibers of 1 denier or less are bundled with a water-soluble binder, cut into short fibers, and entangled using the formed web. Also, Japanese Patent Application Laid-Open
In Japanese Patent Application Laid-Open No. 8-191280, a nonwoven fabric entangled using a web made of fibers that generate ultrafine fibers is exemplified.

However, those using these webs are:
Although the bundle of fibers is temporarily dispersed in the high-pressure water flow, the dispersed fibers are not entangled, and a large number of spreading portions are seen at that portion, and the bundle has a directionality and a bad touch feeling. There is. Further, the web using the web obtained by the dry method has poor web formation.

In Japanese Patent Application Laid-Open No. 54-27067, an ultrafine synthetic filament is provided with a non- (difficult) water-soluble glue material, bundled into a fiber bundle, cut into 20 mm or less, and a web formed by a wet papermaking method is used. JP-A-53-28709 exemplifies an example using a wet web containing splittable fibers.

The formation of the web itself has been improved,
Due to the presence of fiber bundles, the feel is poor. Further, since the knitted fabric is laminated on the knitted fabric, the knitted fabric is expensive and has a disadvantage of lower productivity than the nonwoven fabric.

In Japanese Patent Application Laid-Open No. Sho 53-122869,
A method is described in which an ultrafine fiber web of 0.5 denier or less is formed, laminated on a knitted fabric, and entangled. However, there is a disadvantage that the knitted or woven fabric is expensive and the productivity is low.

As described above, the feel is excellent and the appearance is beautiful.
Further, there is no nonwoven fabric which satisfies all the characteristics of uniformity with excellent strength.

[Problems to be solved by the invention]

According to the present invention, a fiber having a relatively small aspect ratio using ultrafine fibers is formed by a wet paper-making method. The web has a good formation, and is excellent in texture, drapability and strength. It is an object of the present invention to provide a hydro-entangled nonwoven fabric.

In general, the shorter the fiber length and the smaller the aspect ratio, the more free ends of the fiber and the more entanglement and entanglement between the fibers, but the bending of the fiber like a fiber with a large aspect ratio. And the confounding of each one is weak. Fibers having an aspect ratio of 2,000 or less are less likely to be entangled in the dispersion step in water, and it is easy to obtain a web with good formation. In addition, it has been considered that entanglement is easy even when the fiber easily moves by the water flow.

However, fibers having an aspect ratio of 2,000 or less have difficulty in bending the fibers by a water flow, making it difficult to obtain strong entanglement between the fibers, and have a sufficient strength with a conventional nonwoven fabric using ultrafine fibers. Is not expressed. Further, in the jetting process of the water flow, there is a problem that the whole fiber moves due to the bending of the fiber, slip occurs between the fibers, the distortion increases inside the nonwoven fabric, and many wrinkles and irregularities occur in the nonwoven fabric. In particular, as the basis weight of the web to be entangled increases, the above-mentioned problems become more remarkable.

[0019]

Means for Solving the Problems The present inventors diligently studied the above problems. As a result, the present inventors have found that a nonwoven fabric having three-dimensionally entangled wet webs of specific ultrafine fibers and having substantially no pores and satisfying specific conditions of the surface condition and void diameter can solve the above-mentioned problems. In addition, the wet-laid web is loaded on a specific support, and a pressure of a certain level or more,
By applying the applied energy, not only the strength was increased, but also an unexpected result that the tactile sensation, the drape property and the texture were excellent was obtained, and it was found that the above-mentioned problem could be solved. The present invention has been achieved based on these findings.

That is, the hydroentangled nonwoven fabric of the present invention is at least one kind of short fiber having a fiber diameter of 1 to 7 μm and a ratio of the fiber length L to the fiber diameter D (L / D, aspect ratio) is 1
A web obtained by wet-papermaking ultrafine fibers of 2,000 to 2,000, which is a hydro-entangled nonwoven fabric obtained by three-dimensionally entanglement of the ultrafine fibers of the web, has substantially no pores, and has a maximum void value of average Ri der within 5 times the gap value and the friction coefficient of the surface
The number (MIU) is, 1.5 × 10 ^-1 to 3.0 × 10 ^-1,
The standard deviation of the coefficient of friction (MMD) is, 1.5 × 10 ^-2 or less
This is a hydroentangled non-woven fabric having a good texture and a good tactile sensation.

[0021]

Further, the hydroentangled nonwoven fabric having a good tactile sensation in the above-mentioned formation, in which the difference between the front and back of MIU and MMD is 15% or less of the front to back ratio, is provided.

Furthermore, at least one or more of ultrafine fibers and webs by wet papermaking, loaded with web porosity of 40% or less of the porous support on, the following nozzle <br/> diameter 150 [mu] m, 100 Kg / the water flow c m ² or more pressure, total 1
This is a method for producing a hydro-entangled nonwoven fabric excellent in texture and excellent in touch, characterized in that fibers are three-dimensionally entangled by spraying onto a web so as to impart energy of 〜6 KW / Kg / m.

Further, at least once on both sides of the web, and the injection water flow, I said a good preparation der tactile excellent hydroentangled nonwoven fabric formation, characterized in that to perform the confounding
You .

Hereinafter, the present invention will be described in detail. In addition,
In the text, a hydroentangled nonwoven fabric having a good texture and a good feel is simply referred to as a nonwoven fabric. The fibers used in the nonwoven fabric of the present invention are short fibers having a fiber diameter of 1 to 7 μm. This fiber is
Because the fiber diameter is very small, it is called ultra-fine fiber,
A non-woven fabric using this fiber has a very good touch.

The aspect ratio of the ultrafine fibers used in the present invention is preferably from 1,000 to 2,000. Aspect ratio 2
If the fiber exceeds 000, the dispersion process in water is difficult, and it is necessary to select a dispersant and use an appropriate amount. In addition, the dispersion concentration is low, and the productivity is poor.

Although the fibers having an aspect ratio of less than 1000 are more easily moved by the water flow, it is difficult to bend and entangle the fibers, so that it is difficult to obtain a high-strength nonwoven fabric. In addition, since the entire fiber moves, a gap between the fibers occurs, a distortion occurs inside the nonwoven fabric, and a problem that many wrinkles occur in the nonwoven fabric after jetting a water flow occurs. Even so, the solution is difficult.

Fibers having relatively low rigidity allow the fibers to move and bend easily and to be easily entangled. Normally, in the case of fibers having an aspect ratio of 2000 or less, relatively rigid fibers move easily in a water stream, but it is difficult to bend the fibers, and the fibers are not entangled and tend to fall off. difficult.

However, by using ultrafine fibers and entangled under specific high pressure and specific conditions as described later, even fibers having the above-mentioned aspect ratio can be bent by a water stream, and at the same time, have a tactile sensation. It becomes possible to obtain an excellent nonwoven fabric.

The types of fibers used in the present invention include organic synthetic fibers such as polyester fibers, polyolefin fibers, polyacrylonitrile fibers, polyvinyl alcohol fibers, nylon fibers and urethane fibers, as well as recycled fibers and semi-synthetic fibers. And natural fibers.

The polyester fiber refers to a fiber comprising a homopolymer and a copolymer such as polyethylene terephthalate, polybutylene terephthalate, and modified polymers of these polymers.

The polyolefin fiber refers to a fiber comprising a homopolymer and a copolymer such as polypropylene, polyethylene, polystyrene, and modified polymers thereof. Polyacrylonitrile fibers are acrylic fibers,
Modacryl fiber and the like. The polyvinyl alcohol fiber refers to a fiber made of polyvinyl alcohol. Nylon fiber refers to a fiber made of a polymer such as nylon 6, nylon 66, or the like.

[0033] Semi-synthetic fibers refer to fibers such as acetate fibers. The term “regenerated fiber” refers to a fiber obtained by spinning a regenerated cellulose fiber such as rayon or a solution of collagen, alginic acid, chitin or the like. Natural fibers refer to cellulosic fibers such as hemp and cotton, and protein fibers such as wool and silk.

Further, among the fibers used in the present invention, in the case of a synthetic fiber, it may be in the form of a composite fiber comprising two or more of the above-mentioned polymers. The cross-sectional shape of the fiber is
Round, elliptical as well as flat, triangular, Y-shaped, T-shaped, U
It may have a so-called irregular cross-sectional shape such as a mold, a star, a dogbone, or the like. Naturally, in addition to the above-mentioned fibers, a small amount of fibers other than those limited by the present invention can be contained in the nonwoven fabric, but the content must not be in a range that impairs the performance of the nonwoven fabric of the present invention.

The nonwoven fabric of the present invention has an aspect ratio of 200
Zero or less fibers are used, and these fibers are disentangled due to entanglement without bending. These shifts appear as distortions in the nonwoven fabric, and wrinkles occur after the jet of water flow. In particular, when the basis weight of the nonwoven fabric is 50 g / m ² or more, the wrinkles are easily generated. This wrinkle can be suppressed by a method described later, and is particularly effective when the basis weight is 50 g / m ² or more.

A method for obtaining a well-formed web includes a wet papermaking method. Those obtained by other web production methods have poor texture, and it is difficult to produce a nonwoven fabric having an excellent tactile sensation even if ultrafine fibers are used.
Further, the non-woven fabric lacks uniformity, and has a rough feeling due to uneven basis weight.

Further, as the nonwoven fabric having an excellent tactile sensation, a nonwoven fabric having a specific coefficient of friction (hereinafter referred to as MIU) and a standard deviation of friction coefficient (hereinafter referred to as MMD) of the nonwoven fabric is preferable. The friction coefficient and the standard deviation of the friction coefficient described here are 0.5
When a load of 50 g is applied to a 1 × 1 cm terminal wound with a 1 mm diameter piano wire, the terminal is placed 1 m on the surface of the nonwoven fabric.
The average friction coefficient calculated from the average load when sliding at a speed of m / sec, and the standard deviation thereof. The shape of the surface of the terminal is made similar to the fingerprint of the finger, and the feeling when the finger is slid is quantified. If the MIU is small, the sliding feeling is strong, and if it is large, the slimming feeling is large. M
If the MD is small, it is smooth, and if it is large, the roughness is strong.

The preferred MIU is 1.5 × 10 ^{−1 to} 3.
In 0 × 10 ^{over 1,} MMD is 1.5 × 10 ^-2 or less. M
IU in less than 1.5 × 10 ^-1, too slippery surface, 3.
0 for a × larger 10 beyond ^-1 slime is too strong, tactile deteriorates undesirably. The standard deviation is 1.5 ×
More than 10 ^{over 2,} surface roughness, is not preferred.

When ultrafine fibers are used and these ranges are satisfied at the same time, it has a moderate slimy feeling, has a smooth surface,
The resulting nonwoven fabric has a very good touch. Not only the drape property but also such a feeling of friction are very important factors for a nonwoven fabric having an excellent tactile sensation.

It is further preferable that the difference between the front and back of MIU and MMD is 15% or less of the front to back ratio. By making this value as close to 0 as possible, the difference between the front and back sides is reduced, and a nonwoven fabric with excellent touch feeling can be obtained.

Next, it is preferable that the value of the maximum gap is within 5 times the value of the average gap. While the apertures are straight holes through the nonwoven, voids refer to non-linear, meandering paths between the fibers. Here, the void diameter of the nonwoven fabric of the present invention will be described. The pore size is AS
The maximum void diameter and the average void diameter are measured by the bubble point method and the mean flow point method described in TM F-316.

The uniformity of the nonwoven fabric can be evaluated by comparing the average void diameter with the maximum void diameter. Depending on the degree of confounding, these pore diameters change. For example, if the confounding is performed firmly, the diameter of these voids becomes small, and if the confounding is weak, the diameter of the voids becomes large. That is, if there is unevenness of confounding due to shaping of the formation and basis weight, the distribution range of the void diameter is widened. Just because the average of the pore diameters shows a specific value, it cannot be determined that the confounding has been effectively performed. Therefore, it can be considered that the smaller the difference between the average void diameter and the maximum void diameter is, the more uniform the nonwoven fabric, in other words, the more uniformly entangled.

When the maximum void diameter is within 5 times the average void diameter, it is confirmed that the fibers were entangled uniformly. If the maximum void diameter exceeds five times the average void diameter, the nonwoven fabric lacks uniformity, poor formation, uneven entanglement, the nonwoven fabric has a decoy, drapeability of the nonwoven fabric,
The feel is inferior. As described above, by measuring the maximum and average void diameter of the nonwoven fabric, it is possible to evaluate not only the entangled state, the formation and uniformity of the nonwoven fabric, but also the touch and drape property from which these are derived.

Next, a method for producing the nonwoven fabric of the present invention will be described. First, a web manufacturing method will be described. The web is manufactured by a wet papermaking method. Hereinafter, an example of the wet papermaking method will be specifically described. First, the ultrafine fibers are defibrated, and then a uniform dispersion is prepared, and a web is manufactured using a paper machine. Regarding the disintegration of ultrafine fibers, as long as the aspect ratio is within the range of the present invention, a special device is not required, and a beating machine such as a pulper or a beater can be used. However, in order to prevent the fibers from being entangled by a long disintegration operation and to prevent the fibers from being damaged, it is preferable to perform the disintegration in a time as short as possible. The defibrated fiber is immediately diluted with gentle stirring such as an agitator, if necessary, and in order to obtain a uniform dispersion state,
A thickener such as a high molecular weight polyacrylamide or polyethylene oxide may be appropriately added. However, it is preferable to use a blade of an agitator or the like having a thickness as small as possible so that the fibers are not entangled.

Using the fiber suspension (slurry) thus prepared, a web can be obtained by using a paper machine having at least one of a circular net, a long net, a short net, and an inclined type wire. . It is necessary to form a web with as good a texture as possible using the above method.

The web thus prepared was subjected to a porosity of 40
% Or less, and the size of one opening is 0.04 mm ² or less. Next, a high-pressure columnar water stream is jetted from above the web, and the water stream and the web are relatively moved to three-dimensionally entangle the fibers. As a method of relatively moving the web and the water stream, a method of rotating a conveyor-type support or a drum-type support is convenient. At this time, the transport speed of the support is determined by the energy applied to the web, but can be used at a speed of 1 to 200 m / min .

If the porosity of the support is greater than 40%, the resulting nonwoven fabric will have porosity. Conversely, the smaller the porosity, the better the surface quality of the obtained nonwoven fabric, but if the porosity is too small, the water required for the entanglement does not fall down from the support,
After hitting the support, it rebounds to the web again, and the rebound water pushes up the web, causing a phenomenon that the web is broken, which is not preferable.

The size of one of the openings in the support varies depending on the desired basis weight of the nonwoven fabric. That is, to explain with a specific example, when the basis weight is less than 50 g / m ² , the opening area is 0.05 mm ² or less, and 50 to 150 g / m ^2.
When the 0.09 mm ² or less, preferably 0.2 mm ² or less when more than 150 g / m ^2. If a larger one is used, pores are formed in the nonwoven fabric. In addition, the number of fibers coming out at the time of entanglement increases, and further, the surface quality of the nonwoven fabric deteriorates, which is not preferable. Deterioration of surface quality indicates that MIU increases and MMD increases.

The distance between the openings of the support is 0.3
mm or less is preferable. If this interval is large, the amount of rebound water increases as described above, which is not preferable. Examples of such a porous support include a wire such as a metal such as stainless steel or bronze, or a material such as plastic such as reinforced polyester or polyamide in a weave method such as plain weave or twill weave.

When the above-mentioned web and support were used, the water flow had a diameter of 150 μm or less and a pressure of 100 kg / c.
It is preferably at least m ² . The applied energy required to entangle the nonwoven fabric is 1-6 KW / K in total.
g / m.

It is preferable to use a columnar water stream. The columnar water flow is jetted from a small diameter nozzle hole.
If the diameter of this water stream is larger than 150 μm, 100 kg
Injecting a water stream at a pressure of / cm ² or more is not preferred because the web is damaged. In addition, the water flow marks are prominent, the surface quality is deteriorated, and the tactile sensation deteriorates, which is not preferable. The pressure required for confounding 100 Kg / c m ² or more. 100K
By water flow strikes the case of less than g / c m ^2, although the fiber moves, hardly occurs bending, not strong confounding is carried out, also, deviation occurs in fibers, the deviation becomes larger, in the non-woven fabric Distortion occurs and wrinkles occur.

[0052] That is, in 100Kg / c m ² or more of the pressure,
In addition, by jetting a water stream having a diameter of 150 μm or less, the fibers move, bend and are entangled firmly at the same time, and a nonwoven fabric having good surface quality and excellent tactile sensation can be obtained.

The interval between water streams (nozzle hole interval)
Is preferably 1.5 mm or less. If the distance is wider than 1.5 mm, not only the efficiency of the confounding is poor, but also the trace of the water flow becomes noticeable and the tactile sensation deteriorates.

The total amount of applied energy required for confounding is preferably 1 to 6 KW / Kg / m. 1KW / Kg /
If it is less than m, not only the entanglement is insufficient and a nonwoven fabric of sufficient strength cannot be obtained, but also the surface strength is weak and the detachment of fibers increases. On the other hand, if an applied energy of more than 6 KW / Kg / m is applied, the unwoven fabric is excessively entangled, so that the nonwoven fabric becomes hard and the touch feeling is unfavorably deteriorated.

The applied energy required for confounding is calculated by the following equation. E = 9.23 × Q × P / (v × M) E: Energy applied by one head per 1 kg of web per 1 m width, unit is KW / Kg / m (kilowatt / kg / kg) Q) Flow rate of water applied per meter width of web for 1 hour from one head, unit is m ³ / hr / m P: Pressure of water flow, unit is Kg / cm ² v: Relative speed of head and web , The unit is m / min M: the basis weight of the web, the unit is g / m ^2, where the flow rate is calculated by the following formula. Q = 0.02448 × A × (2P) ^1/2 ... A: The total aperture area of the nozzle per 1 m width mounted on one head, and the unit is mm ^2. The applied energy per 1 m width per head is calculated as 0.226 × A × (2P) ^1/2 × P / (v × M).

According to the above-mentioned method, even if the aspect ratio is not so large, the fiber can bend and exhibit a strong entanglement, and also a nonwoven fabric excellent in tactile sensation, drapability and texture can be obtained. In addition, regarding the confounding device,
It is important to select the number of nozzle heads and the number of entanglements within a range where sufficient entanglement can be obtained in consideration of the type of the web, the basis weight, the processing speed, and the water pressure.

As the entanglement, either one side or both sides can be selected, but in order to reduce the difference between the front and back sides, it is preferable to perform the entanglement by injecting a water flow at least once on both sides of the web. First, after confounding one side, by performing confounding from the opposite side, the difference between MIU and MMD is reduced. It is better to increase the number of confounds, that is, the number of web inversions, MIU,
It is preferable from the viewpoint of reducing the difference in MMD and further improving the surface quality. Further, after the entanglement is performed, the web can be further laminated to perform the entanglement.

As a method of further improving the surface quality, the nozzle diameter and the nozzle interval may be reduced individually or in combination with each other, the nozzle head may be rotated, vibrated to the left and right, or the support of the web may be moved to the left or right. And vibrating. Further, after the entanglement, the surface quality can also be improved by inserting a wire mesh of 40 to 100 mesh between the nozzle and the web to sprinkle the columnar water stream and spray it on the web.

The web subjected to the entanglement treatment as described above is subjected to a method such as suction or wet pressing during or after the entanglement to remove excess moisture, and then an air drier, an air through drier, a suction drum drier or the like is used. Can be used for drying. Before drying, treatments such as embossing and creping may be performed.

Of course, it is possible to entangle the nonwoven fabric with another nonwoven fabric such as a dry nonwoven fabric, a pulp sheet, a wet nonwoven fabric containing fibers deviating from the claims of the present invention by one side, both sides, or a sandwich. Needless to say, it should not be a range that hinders the object of the invention.

Further, a small amount of a binder may be applied to the web before the entanglement, a temporary adhesive may be applied, and once wound up, a single layer or a laminated layer may be entangled. However, as the binder to be used, a binder whose adhesion is released by entanglement is preferable. For example, water-soluble polyvinyl alcohol, carboxymethyl cellulose and the like are exemplified. Further, the binder component remaining on the web can be further removed by a method such as water washing and hot water washing as necessary.

The spun lace nonwoven fabric with good formation of the present invention obtained by the above-mentioned method is bent, resin-impregnated, water-repellent, hot-pressed, embossed, kneaded, softened, etc. Post-processing can be performed, and thereby new performance can be provided.

The nonwoven fabric of the present invention can be used for medical and sanitary materials. It is suitable for applications such as masks and surgical gowns because of its excellent drapability, the use of ultrafine fibers, excellent tactile sensation and excellent barrier properties.

Further, utilizing the barrier property, it is suitable for use as a filter for liquid or gas.

Further, since the strength is high and the entanglement of the fibers is strong, the use as a simple garment that can be used a plurality of times is also conceivable.

Further, a web containing so-called ultrafine fibers having a fine fiber diameter is laminated, and is suitable for use as a base material for synthetic leather because of its good texture and good texture. By impregnating these base materials with an elastic polymer, they can be used as base materials for synthetic leather excellent in soft touch. In particular, it is suitable for use as a base material for high-quality suede-like or grainy artificial leather.

In addition, it is suitable for applications such as surface materials, felts, wipers, interlining for clothing, base fabric for tape, cushioning materials, backing materials and the like. As described above, examples of the use of the nonwoven fabric of the present invention have been described, but it should be noted that the use is not limited to these.

[0068]

The non-woven fabric of the present invention is a soft non-woven fabric having a good texture, in which the fibers are entangled by a high-pressure columnar water flow from a web made by a wet papermaking method using ultrafine fibers. By applying energy at a specific pressure and a nozzle to a well-formed web of ultrafine fibers having a specific aspect ratio,
It is a nonwoven fabric that is uniformly and firmly entangled, has high strength, and is excellent in drapability and tactile sensation, and cannot be obtained by conventional methods.

[0069]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.
All parts and percentages described in the examples are by weight.

The tensile strength shown in the examples was 20 mm in width,
150mm length sample, span 100mm, speed 200cm
The longitudinal direction (the direction in which the web was conveyed) and the lateral direction (the direction perpendicular to the direction of conveyance) were measured at the maximum load value until the sample was broken when the sample was pulled at / min.

As the air permeability, a pressure loss measured at a wind speed of 5.3 cm / sec according to JIS-B9908 type 1 was obtained. The void diameter of the nonwoven fabric was determined by the bubble point method and the mean flow point method described in ASTM-F-316 to determine the maximum void diameter (MAX) and the average void diameter (MFP).

The bending resistance was measured using the 45-degree cantilever method described in JIS-L1096, and the average value in the vertical and horizontal directions was shown. The coefficient of friction (MIU) and its standard deviation (MMD) of the nonwoven fabric are measured using a friction tester (model KES-F).
B, manufactured by Kato Tech Co., Ltd.). The vertical and horizontal front and back were measured at five points each, and the average value of the front and back was obtained. In addition,
For convenience, the last entangled surface is referred to as the back surface.

The formation of the non-woven fabric was visually evaluated by holding it over the transmitted light, and was evaluated on a four-point scale: ◎ is very good, 良 い is good, △ is slightly bad, and × is bad. The feel of the nonwoven fabric was the feel of the fine fiber side. In addition, they rubbed a little with both hands and looked at them. In all cases, ◎ was evaluated as 4 grades: very good, 良 い good, △ slightly bad, and × bad.

Example 1 Polyethylene terephthalate (PET) fiber having a fineness of 0.1 d and a fiber length of 5 mm (fiber diameter 3 μm, L / D = 1.3 × 1)
0 ^3, manufactured by Teijin Co., Ltd.) was dispersed in water.

In the papermaking method, first, a 1% nonionic dispersant was added to water, and then the above-mentioned fibers were added to water and stirred by an agitator to prepare a suspension. Next, a 0.1% high molecular weight polyacrylamide solution (viscosity agent) was added,
Viscosity increased and a uniform dispersion state was obtained. Thereafter, the paper was made with an inclined short-mesh paper machine, made into a basis weight of 80 g / m ² by dry weight, and further entangled.

For the confounding, five nozzle heads were used. The nozzle (water flow) diameter, nozzle (water flow) interval and pressure of each head are shown. The front surface was entangled with the nozzle arrangement shown in Table 1, and the rear surface was entangled with the nozzle arrangement shown in Table 2.

[0077]

[Table 1]

[0078]

[Table 2]

However, the head of No. 5 on both sides used a thin water stream at low pressure for surface adjustment. By using such a water flow, the trace of the water flow can be eliminated or alleviated. Therefore, the applied energy required for confounding refers to the applied energy consumed by the No. 1 to No. 4 heads.

The web has a stainless steel wire diameter of 0.112.
Opening ratio 34 in plain weave using monofilament of mm
%, One hole was loaded on a wire-like support having a size of 0.023 mm ² , and the web was passed at a speed of 15 m / min under the water flow shown in Table 1 above. The water stream of No. 2 was jetted to strongly entangle the fibers from the front and back of the web. The applied energy was 2.16 kw / kg / m. The entangled web was dried at 110 ° C. using a suction drum dryer to obtain a nonwoven fabric. Table 5 shows the results.

Example 2 Acrylic fiber having a fineness of 0.1 d and a fiber length of 6 mm (fiber diameter of 3.
5 μm, L / D = 1.7 × 10 ³ , manufactured by Mitsubishi Rayon Co., Ltd.)
Was dispersed in water, and a web was formed so that the basis weight after drying was 35 g / m ² . However, the disintegration of the fiber, after using a pulper and strongly stirring with a nonionic surfactant,
Transfer to a chest with agitator, add glue,
A uniformly dispersed slurry was prepared. Thereafter, the paper was produced in the same manner as in Example 1.

For the method of confounding,
The stacking was performed at a speed of 10 m / min. However, the pressure of each nozzle is shown in Table 3 for the front surface and Table 4 for the back surface. The applied energy was 4.69 kw / kg / m. Table 5 shows the results.

[0083]

[Table 3]

[0084]

[Table 4]

Example 3 PET fiber having a fineness of 0.15 d and a fiber length of 5 mm (fiber diameter of 4 μm)
m, L / D = 1.25 × 10 ³ , manufactured by Asahi Kasei Corporation)
A web having a basis weight of 35 g / m ^{2 was} produced in the same manner as in Example 1. Thereafter, confounding was performed in the same manner as in Example 2. However,
The confounding speed was 20 m / min. The applied energy is
It was 2.34 kw / kg / m. Table 5 shows the results.

Comparative Example 1 Entangling was performed in the same manner as in Example 2. However, the confounding pressure is 50, 50, 50, 50, 10 kg / cm ^{2 in} order.
The back surface was also subjected to the same pressure. The speed was 3 m / min. The applied energy was 2.74 kw / kg / m. At this pressure, even when the entanglement is performed from the front and back, not only the entanglement cannot be sufficiently performed, but also the water flow does not penetrate the web, so that the water flow rebounds in the web and the web surface is damaged. Further, at the time of back entanglement, after passing the No. 1 head, a large wrinkle was generated on the web, and a water flow hit the wrinkle, and the appearance of the nonwoven fabric was extremely poor. Table 6 shows the measurement results.

Comparative Example 2 Entangling was performed in the same manner as in Example 2. However, the confounding speed was 50 m / min. 0.82kw applied energy
/ Kg / m. Table 5 shows the results. Perhaps due to the small applied energy, the surface is weak, and the fibers easily fall off when touched a little. Moreover, it peeled easily between the layers. Table 6 shows the measurement results.

Comparative Example 3 Entangling was carried out in the same manner as in Example 2. However, when a stainless steel monofilament having a wire diameter of 0.34 mm was used as the support, and a plain weave having an opening ratio of 42% and one opening area of 0.44 mm ² was used, an opening was formed in the nonwoven fabric. The nonwoven fabric had a different purpose from the nonwoven fabric of the present invention. Table 6 shows the measurement results.

Comparative Example 4 Fineness 1.5d, fiber length 38 mm (fiber diameter 12.4 μm, L
/D=3.1×10 ³ ) using a random card and further laminating a web to obtain a basis weight of 80 g / m 2.
² was manufactured and entangled in the same manner as in Example 2. Although this nonwoven fabric had high strength, the fiber diameter was large and the formation was poor, so that the feel was inferior to that of the nonwoven fabric of the present invention.

Example 4 Entangling was carried out in the same manner as in Example 2. However, the basis weight of the web before entanglement was 40 g / m ^2, and four sheets of the web were laminated and entangled. However, the support is made of stainless steel and has a wire diameter of 0.21.
Opening ratio of 32 with plain weave using monofilament of mm
%, One hole area of 0.44 mm ² , and the web was conveyed at a speed of 15 m / min. Also, after confounding,
Furthermore, the front and back were entangled under the same conditions. The applied energy was 2.74 kw / kg / m. Table 5 shows the results.

Example 5 Entangling was performed in the same manner as in Example 4. However, the web transport speed was 10 m / min, and the number of laminated sheets was seven. The applied energy was 2.34 kw / kg / m. Table 5 shows the results.

[0092]

[Table 5]

[0093]

[Table 6]

[0094]

As described above, the fibers constituting the wet-laid web made of ultrafine fibers having a specific fiber diameter and an aspect ratio are three-dimensionally entangled with each other and have a specific void diameter and a specific feeling of friction, so that good formation is obtained. Thus, it is possible to obtain a hydroentangled nonwoven fabric which is excellent in drapability and tactile sensation and has high strength. This hydro-entangled non-woven fabric uses a specific support, sprays a high-pressure water stream with a specific applied energy and a pressure equal to or higher than a certain value to the web, thereby suppressing distortion in the non-woven fabric and causing wrinkles in the non-woven fabric. It is possible to manufacture without.

Continuation of the front page (56) References JP-A-4-185793 (JP, A) JP-A-3-14694 (JP, A) JP-A-56-169899 (JP, A) JP-A-5-163650 (JP) , A) (58) Fields investigated (Int. Cl. ⁷ , DB name) D04H 1/00-18/00

Claims (4)

(57) [Claims] 1. A fiber having at least one kind of fiber having a diameter of 1 to 7
μm short fibers, and the ratio of fiber length L to fiber diameter D (L /
D, aspect ratio) is a web obtained by wet-making ultrafine fibers having a thickness of 1,000 to 2,000.
This is a hydro-entangled nonwoven fabric that is dimensionally entangled, has substantially no openings, and has a maximum void value within 5 times the average void value.
And the coefficient of friction (MIU) of the surface is 1.5 × 10
^{−1 to} 3.0 × 10 ⁻¹ , the standard deviation of the friction coefficient (MM
D) is 1.5 × 10 ^-2 or less, the hydroentangled nonwoven fabric having good texture and excellent tactile sensation. 2. The difference between the front and back of MIU and MMD is
2. The method according to claim 1, wherein the average is 15% or less.
Hydro-entangled nonwoven fabric with good texture and good feel. 3. The water according to claim 1, which is excellent in texture and good feel.
A method for producing a fluid-entangled nonwoven fabric, comprising at least one
The ultrafine fiber is web-formed by wet papermaking, and the web is opened.
Loaded on a porous support having a porosity of 40% or less,
With the following nozzle diameter, water with a pressure of 100 kg / cm ² or more
Flow with a total applied energy of 1-6 KW / Kg / m
Sprayed onto the web to give the three-dimensional fibers
Water flow with good tactile sensation
Manufacturing method of entangled nonwoven fabric. 4. The method of claim 1 , wherein both sides of the web are watered at least once.
Injecting by flow and performing confounding
3. The hydro-entangled non-woven fabric which is excellent in texture and good touch as described in 3.
Construction method.