JP3081853B2 - Hydro-entangled nonwoven fabric with good formation 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 nonwoven fabric which has a good formation and is excellent in drapability, texture, air permeability and strength, and a method for producing the same.

[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.

[0003] Among them, using a high-pressure columnar water stream to reduce the fiber
The development of a so-called spunlace nonwoven fabric or a hydroentangled nonwoven fabric which is dimensionally entangled and has a texture like a woven fabric has been actively developed, and many products have been put on the market. Since the hydroentanglement (spunlace) method is one of the processing methods of the web, it is necessary to supply the web before processing. Examples of the web production method include a dry method such as a card method and an air lay method, a melt blow method, a spun bond method, and a wet papermaking method.

In the card method, fibers having a long fiber length can be used. However, it is difficult to form a uniform web, and it is processed by a high-pressure columnar water flow. 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 feel and texture.

[0005] Using the web obtained by the spunbond method,
Although the strength is large, the formation is poor, the fibers are continuously connected, the free ends of the fibers are few, and a large amount of energy is required for three-dimensional entanglement, and compounding by mutual entanglement with other webs Is difficult. In the melt blow method,
Although it is possible to form a web of fine fibers, there are problems that formation is poor, production speed is low, strength is low, and the cost is high.

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. In other words, in the form of fibers, there is a wide range of choices, such as staple and pulp, and the fiber diameter that can be used can be from ultra-fine fibers to thick fibers. This is the method by which the 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 of fiber diameter (D) to fiber length (L) (L / D, aspect ratio) 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.

[0008] This nonwoven fabric is noted as an improvement over the disadvantage of conventional wet nonwoven fabrics, namely, the disadvantage that the fiber length is short and the strength is weak. That is, the hydroentangled nonwoven 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 that can move freely at the time of entangling, and a large number of fibers are uniformly entangled. Therefore, it is stated that the strength is developed.

However, in the prior art of this specification,
In order to uniformly disperse fibers in water, a fiber length of about 3 to 7 mm is generally required, and a nonwoven fabric processed from a wet web having a fiber length of more than 7 mm has a poor formation.
Further, as shown in Comparative Example 2, the entanglement of the fibers in the slurry state is considered to be a cause of a decrease in drapability and insufficient strength of the nonwoven fabric after entanglement.

Japanese Patent Application Laid-Open No. 3-14695 discloses an example using a wet papermaking web in which a preferable fiber length is 15 mm or less. It is considered that the fiber is entangled and the texture is lowered rather than the length becomes longer and the confounding becomes difficult.

From this, the aspect ratio becomes large, and the movement of the fiber at the time of confounding is suppressed.
Since the formation deteriorated and the movement of the fibers was suppressed, it can be considered that the performance of the nonwoven fabric, such as the drapability and the strength, was reduced.

On the other hand, when using a web by a dry method, especially a card method, a preferable fiber length is set to 20 to 100 mm. In the case of the card method, a fiber having an appropriate free-cut end and having a long fiber length (effectively used for entanglement) can be used. For this reason, it is considered that the fiber length is longer than that of the wet method, and that the strength of one fiber is wide and the strength is expressed in addition to the strength due to the entanglement.

[Problems to be solved by the invention]

The present invention makes use of the advantages of the wet papermaking method and the dry web to produce a web having good formation and a long fiber length by the wet papermaking method.
An object of the present invention is to provide a uniform nonwoven fabric having a good texture, good air permeability, and good texture.

[0014]

Means for Solving the Problems The present inventors diligently studied the above problems. As a result, it is manufactured from a wet papermaking web and contains fibers having a fineness of 0.3 denier (hereinafter abbreviated as d) or more, these fibers have a specific aspect ratio, are three-dimensionally entangled, and have a specific void. By having a diameter,
It has been found that a nonwoven fabric having good formation and excellent strength, drapability, texture, air permeability and the like can be obtained. In addition, it has been found that a web having a good formation can be produced by carefully producing fibers having a specific aspect ratio by a wet papermaking method, and the above nonwoven fabric can be produced by three-dimensional entanglement.

That is, the present invention provides a water-soluble binder
In a nonwoven fabric in which a wet-laid web containing a single layer or a laminate is laminated and the fibers in the web and between the layers are three-dimensionally entangled and the single layer or the layers are not substantially peeled off, a good hydroentanglement that meets the following conditions is satisfied. It is a non-woven fabric. Fineness 0.3
It consists denier or more fibers, and a ratio of fiber length within the 0.3 denier or more fibers (L) and fiber diameter (D) (L /
D, aspect ratio) of greater than 2000 contains 10 to 90% by weight of the weight of the hydroentangled nonwoven fabric. The value of the maximum gap diameter with respect to the average gap diameter is within 5 times.

After dispersing fibers having a fineness of 0.3 denier or more and an aspect ratio of 2,000 or less in water, fibers having an aspect ratio of more than 2,000 are dispersed in water, or both are dispersed at the same time. Is not tangled ,
To prepare a slurry containing the water-soluble binder, and papermaking using a wet papermaking method, the resulting web, a single layer or a plurality of stacked, or, laminated with other nonwoven fabric is placed on the support,
This is a method for producing a hydro-entangled nonwoven fabric, characterized by injecting a high-pressure columnar water stream from above the sheet, three-dimensionally tangling the fibers, and drying.

Hereinafter, the present invention will be described in detail. Also,
A hydroentangled nonwoven fabric having good formation is hereinafter abbreviated as a nonwoven fabric in the text. The fibers used in the nonwoven fabric of the present invention have a fineness of 0.3d or more. More preferably, 0.3 to 5
d. When the thickness is smaller than 0.3 d, the strength is low in view of the field of application of the nonwoven fabric of the present invention, and it is not preferable because it is dense and has poor air permeability. If it exceeds 5d, the fiber diameter is large, so that the surface properties of the nonwoven fabric deteriorate, which is not preferable. As will be described later, the fiber length becomes very large in the range of the aspect ratio of the present invention, and it is difficult to form a web having a good formation.

It is preferable to use fibers having an aspect ratio of more than 2000 at a specific ratio. Other than this fiber, a fiber of 2000 or less is used. Hereinafter, fibers having an aspect ratio larger than 2000 are referred to as high L / D fibers,
Fibers of 00 or less are abbreviated as low L / D fibers.

In the present invention, the high L / D fiber is preferably contained in an amount of 10 to 90% by weight based on the weight of the nonwoven fabric. 10
When the amount is less than the weight percentage, not only the strength of the nonwoven fabric is weak, but also a large number of cut ends of the fibers are exposed on the surface of the nonwoven fabric, and the feel is deteriorated.

By containing 10% by weight or more of the high L / D fiber, the strength of the nonwoven fabric is increased and the feel is improved. This is because not only the entanglement between the high L / D and the low L / D fibers but also the entanglement between the high L / D fibers is sufficiently performed. Even if the high L / D fiber exceeds 90% by weight, the effect of increasing the strength is less than that in the range of 10 to 90% by weight. By containing 10% by weight or more of low L / D fiber,
High L / D fiber is 10 to 9 because papermaking is easy.
A range of 0% by weight is preferred.

However, the fiber length of the high L / D fiber is preferably 50 mm or less even when the above conditions are satisfied. Even if fibers longer than 50 mm are mixed with low L / D fibers, the fibers become entangled and difficult to make.

The reason why the high L / D fiber and the low L / D fiber are used will be described in more detail. It is considered that the strength of the nonwoven fabric by the hydroentanglement method is determined by the state of the entanglement and the balance between the fiber length and the aspect ratio. However, considering that the good fiber length for the confounding in the case of the dry method is 20 to 100 mm, if the fiber length of the present invention is within the range of the aspect ratio, the longer fiber length and the larger aspect ratio are preferable. As a result, the strength of the nonwoven fabric increases. In the range of the fiber length, the cause of the decrease in the strength despite the increase in the aspect ratio of the fiber length is a decrease in the formation of the web.

In general, the shorter the fiber length, the more free ends of the fibers and the more entanglement between the fibers, but since the fibers are short, the fibers that can be entangled are limited to the fibers closest to the fibers. Conversely, as the fiber length increases, the free ends decrease, but since the fiber length is long, the range of entangled fibers is wide.
Thus, the degree of entanglement depends on the fiber length and the free ends. However, in a dry web, since a fiber length of 20 mm or more is effective, it is considered that a difference in strength due to a difference in fiber length is larger than a difference in strength due to a difference in the number of free ends of fibers.

[0024] In addition, the easier the fibers are to move during the entanglement, the easier the entanglement and the greater the developed strength. It is considered that the ease of movement of the fibers is greatly affected by not only the aspect ratio of the fibers but also the fiber arrangement of the web, that is, the formation. That is, if the aspect ratio is 2
Even if it exceeds 000, a better nonwoven fabric can be obtained by providing a web with good formation. On the other hand, in a poorly formed web, since the movement of the fibers is suppressed, the strength is not developed for the fiber length.

For the above reasons, the aspect ratio of 2000
When only the following fibers are used, the fiber length of the fibers used is short, so that a nonwoven fabric having a good formation and a certain strength can be obtained, but is not sufficient. It is thought that the inclusion of fibers larger than 2,000, that is, high L / D fibers, results in a better nonwoven fabric.

However, those having an aspect ratio exceeding 5000 or having a fiber length exceeding 50 mm are:
At the current technical level, wet papermaking is difficult, the formation of the web is poor, the free movement of the fibers is suppressed, and the entanglement cannot be performed firmly. Because there is a weak part of such confounding,
Conversely, not only does the strength decrease, but also the uniformity of the nonwoven fabric is impaired due to uneven entanglement, and the texture decreases, resulting in poor texture, drapeability, and the like.

In the present invention, it has been found that by incorporating high L / D fibers with low L / D fibers, a hydroentangled nonwoven fabric having high strength and good formation can be obtained. High L / D
Although it is possible to disperse only the fibers, it is necessary to pay attention to disaggregation and dispersion so that the fibers are not entangled. That is, it is necessary to pay attention to the shear given to the fibers during the defibration and the stirring state after the dispersion, and it is necessary to lower the dispersion concentration.

In the present invention, by mixing the high L / D fiber with the low L / D fiber at a specific ratio, the high L / D fiber is not easily entangled, and not only is the dispersion easy, but also the dispersion state is improved. The production of a stable and well-formed web became possible.
The hydroentangled nonwoven fabric using this web has good formation and high strength. That is,
The use of the low L / D fiber not only increases the dispersion concentration, but also has the effect that the low L / D fiber enters between the high L / D fibers and stabilizes the dispersion state. Even if low L / D fibers are contained, a nonwoven fabric with high strength can be obtained within the range of the present invention.

The 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;
Fibers such as semi-synthetic fibers and natural fibers.

The polyester fibers are fibers comprising homopolymers and copolymers such as polyethylene terephthalate, polybutylene terephthalate, and modified polymers of these polymers.

The polyolefin fibers include fibers made of homopolymers and copolymers such as polypropylene, polyethylene, polystyrene, and modified polymers thereof.
The polyacrylonitrile fiber refers to acrylic fiber, modacrylic fiber and the like, the polyvinyl alcohol fiber refers to a fiber comprising polyvinyl alcohol and the like, and the nylon fiber refers to a fiber comprising a polymer such as nylon 6 and nylon 66.

Semi-synthetic fibers are fibers such as acetate fibers,
The regenerated fiber is 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.

The cross-sectional shape of the fiber used in the present invention is as follows:
Not only circular and elliptical shapes but also triangular, Y-shaped, T-shaped, U-shaped, star-shaped, dog-bone-shaped and so-called irregular cross-sectional shapes may be employed.

The fibers having a fineness of 0.3d or more used in the present invention have relatively low rigidity, so that the fibers tend to move, bend and twist, and are easily entangled. In the case of fibers with a small aspect ratio, fibers with relatively high stiffness are difficult to bend or twist, though they move, and they tend to fall off the web rather than entanglement, making them unsuitable for entanglement. is there.

However, the high L / D fiber can be bent even if the fiber has high rigidity, and can be entangled if the entanglement is performed at a higher water pressure. In addition, a web containing high L / D fibers also has an unexpected effect of preventing falling of low L / D fibers. If a web is used in which the fibers are fixed with a binder component that elutes or loses contact during the entanglement, the entanglement can be performed at a higher water pressure.

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.

Next, the pore size of the nonwoven fabric of the present invention will be described. The void diameter is measured as a maximum void diameter and an average void diameter by a bubble point method and a mean flow point method described in ASTM 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, formation,
If there is unevenness of confounding due to deviation of the basis weight, the distribution range of the void diameter becomes wider. 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 are entangled uniformly. When the maximum void diameter exceeds 5 times the average void diameter, the nonwoven fabric lacks uniformity, has poor formation, has uneven entanglement, has poor strength of the nonwoven fabric, and has poor drapeability and soft touch of the nonwoven fabric. . Thus, the maximum of non-woven fabric,
By measuring the average pore diameter, the entangled state, the formation of the nonwoven fabric,
It is possible to evaluate not only the uniformity but also the softness and drape property derived from these.

Next, the nonwoven fabric manufacturing method of the present invention will be described. The fiber used in the present invention has a large aspect ratio, and it is necessary to pay particular attention to prevent the fiber from being tangled in the defibration and dispersion steps. As described above, the decrease in formation due to fiber entanglement in the web obtained by wet-laid paper greatly affects the performance of the nonwoven fabric.

In the method of the present invention, since the low L / D fiber is used, the dispersibility of the fiber is improved as compared with the case where only the high L / D fiber is used. That is, it is considered that fibers having a small aspect ratio enter between the large fibers, and the entanglement of these fibers is suppressed. It is believed that the low L / D fibers act as a kind of buffer. Therefore, not only the initial dispersion but also the dispersion state of the slurry is stably maintained well.

When the high L / D fibers are relatively easy to disintegrate, the order of mixing the fibers into water is not particularly limited. However, when the disintegration is difficult and the fibers are easily entangled, the fibers having a smaller aspect ratio are used. The fibers are less likely to be entangled when charged in order. It is considered that the low L / D fibers dispersed first enter the high L / D fiber intervals to be defibrated and dispersed sequentially.

Further, the method of uniformly dispersing the dispersant in an aqueous solution before the fiber is defibrated or the method of immersing the fiber in a solution of about 1% of the dispersant in advance promotes the defibration of the fiber. The above is preferable, and is effective in preventing entanglement after disaggregation. For disaggregation and dispersion, a rotary type can be used. At this time, it is necessary to pay attention to the wings of the rotating object. Since the wing is a portion where fibers are entangled and cling easily, the wings are preferably thicker than when dispersing fibers having a small aspect ratio. Furthermore, it has a thickness of 1/3 or more of the fiber length of the largest fiber length,
Rounded ones are preferred.

Regarding the stirring, it is preferable to perform stirring for disaggregation promptly, even if the fibers are not entangled.
If the fibers are not sufficiently disintegrated by short-time stirring, the stirring speed is instantaneously increased, and an impact is applied to the undisintegrated fiber bundle.
A method that promotes disaggregation is preferred. The stirring speed is only temporarily increased, and if the stirring time is long, binding between fibers is formed, which is not preferable. When disaggregation is not performed once, it is preferable to repeat the process of slowing the stirring speed and then increasing the stirring speed for a short time. Furthermore, it is also effective to carry out a short-time treatment with a beater for the purpose of intermittently giving undisintegrated fibers a share.

Next, when disintegrating the disintegrated fibers, in order to prevent the fibers from being entangled, the dispersion of the fibers is maintained, and the dispersion is performed under gentle stirring as much as possible. If necessary, the slurry of the defibrated slurry is further added with water to reduce the concentration, and then the viscosity is immediately added to maintain the dispersion. During this time, stirring is performed as slowly as possible as described above. In this way, a uniformly dispersed slurry is prepared. Here, “uniform” refers to a state in which fibers are not substantially entangled or aggregated (flock) during stirring.

The slurry thus prepared can be paper-formed by a wet paper-making method to form a web. The web may be continuously three-dimensionally entangled with a high-pressure water stream.
Also, a binder is applied to the web, and after papermaking, dried,
After winding once, three-dimensional confounding may be performed. The method of applying the binder is preferably a method in which the binder is applied in a slurry if it is a fibrous material, or after papermaking and before it is dried if it is a liquid material. The web can be dried by a normal drying method using a Yankee dryer, a multi-cylinder cylinder dryer, an air dryer, or the like.

Here, the binder used includes liquid and fibrous binders. Examples of the fibrous material include one utilizing entanglement with the main fiber and one utilizing adhesiveness to the fiber.

As for the liquid, those which dissolve during the confounding process are preferred. Therefore, a water-soluble one is preferable. Further, a method in which these water-soluble binders are formed into a fibrous form and formed together with the main fibers is also a preferable method. The amount of liquid binder applied is 1 to 10 with respect to the sheet weight.
% By weight is preferred. If it is less than 1% by weight, the sheet strength is weak, and if it is more than 10% by weight, the bonding between the fibers is too strong, and it is difficult to cut the bonding and perform a new three-dimensional entanglement. Therefore, when the layers are stacked, the entanglement between the layers is weak, and delamination occurs.

It is preferable that the fibrous binder be one in which the bond with the main fiber is released in the course of confounding and three-dimensional confounding is newly developed.

Therefore, the amount of the binder to be applied is preferably 3 to 20% by weight based on the weight of the sheet in the case of adhesiveness. If it is less than 3% by weight, the strength after papermaking cannot be obtained. If it exceeds 20% by weight, the movement of the fiber is suppressed,
The confounding cannot be performed firmly. After lamination, delamination occurs.

In the case of utilizing the entanglement with the fiber, the structure has a branched structure. When the branched portion has the fineness and the aspect ratio of the main fiber of the present invention, the amount is not limited. However, if it is out of this range, it is still 3 to 20% by weight.
Is preferable.

When the sheets using the binder are entangled with each other, in this step, the formation is not disturbed and a nonwoven fabric having a good formation can be obtained. It is presumed that confounding occurs immediately after the adhesion is released.

Using the web or sheet obtained in this way, three-dimensional confounding is performed with a high-pressure columnar water flow. In the entanglement method, a single layer or a plurality of webs or sheets are laminated, placed on a support of about 50 to 200 mesh, and a water stream is jetted from above to perform three-dimensional entanglement of the fibers.

The conditions for performing the confounding firmly and properly according to the purpose will be described below. The diameter of the nozzle for jetting the water flow is preferably in the range of 10 to 500 μm. The interval between the nozzles is preferably 10 to 1500 μm.

These nozzles need a range that covers the width of the sheet to be processed in the direction perpendicular to the papermaking direction.
For the papermaking direction, web type, basis weight, processing speed,
In consideration of the water pressure, the number of nozzle heads can be changed and used as long as sufficient confounding can be obtained. Also, the number of confounds can be arbitrarily selected.

The water pressure is preferably used in the range of 10 to 250 kg / cm ² . More preferably, 50 to 250 kg /
cm ² range. If it is less than 10 kg / cm ² , sufficient fiber entanglement cannot be obtained. If it is larger than 250 kg / cm ^2, the fibers will fall off the web significantly, and the sheet will be damaged. However, it should be added that the upper limit of the confounding water pressure changes depending on the basis weight and the fiber rigidity. Under the conditions of the present invention, when the basis weight is 50 g / m ² or more, it is effective from the viewpoint of strength that the confounding is performed at a pressure of 140 kg / cm ² from at least one row of nozzles.

The web can be transported at a speed of 5 to 200 m / min. If the transport speed is low, the web may be damaged by a water stream hitting the web, and this is not preferable in terms of production efficiency. If the transfer speed is too fast,
Since the energy required for confounding cannot be given to the web, confounding cannot be performed firmly.

By arranging the nozzles stepwise and increasing the water pressure sequentially from the beginning to the end of processing, damage to the web can be reduced and confounding can be performed properly. It is also preferable from the viewpoint of improving the surface quality. Similarly, it is preferable to sequentially reduce the nozzle diameter or the nozzle interval, or both, from the viewpoint that entanglement can be properly performed and the surface quality of the nonwoven fabric is improved.

Further, the surface quality can be further improved by rotating the nozzle header, oscillating it left and right, or oscillating the support wire of the web right and left. 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 confounding method can be performed on one side only or on both sides. After the confounding, it is also possible to further laminate a web or the like and perform the confounding.

The web obtained in this manner and subjected to the three-dimensional entanglement treatment is subjected to a method such as suction or wet pressing during or after the entanglement, to remove excess moisture, and then to an air dryer, an air through dryer, or Drying can be performed using a suction drum dryer or the like.

The nonwoven fabric containing the fibrous binder described above can be dried at a temperature higher than the melting point of the binder component for the purpose of improving the strength. The same effect can be obtained by applying heat and pressure to the entangled web entirely or partially. However, when it is necessary to obtain a softer nonwoven fabric, it is necessary to dry at a temperature lower than the melting point of the binder.

Of course, other nonwoven fabrics such as dry nonwoven fabrics, pulp sheets, wet nonwoven fabrics containing fibers which do not fall within the scope of the present invention, and the like can be entangled with the nonwoven fabric on one side, both sides, or a sandwich. Needless to say, it should not be a range that hinders the object of the invention.

The spun lace nonwoven fabric with good formation of the present invention obtained by the above-described method can be subjected to post-processing such as bending, resin impregnation, and water repellency. Performance can be imparted.

The nonwoven fabric of the present invention can be used for medical and sanitary materials. It is rich in drape, soft and comfortable, and the pore size can be controlled by changing the fiber diameter, confounding water pressure and support. In addition, a barrier property can be imparted by laminating a pulp layer, which is suitable for applications such as masks and surgical gowns.

Further, since it has good air permeability, it is suitable for use as a prefilter for liquid or gas.

Further, because of its good texture and good texture, it is suitable for use as a base material for synthetic leather, and can be impregnated with an elastic polymer. Also, at the time of three-dimensional confounding, by laminating a web made of so-called ultrafine fibers having a fine fineness and performing confounding, it is suitable for use as a base material for high-quality suede-like artificial leather. 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 nonwoven fabric of the present invention uses a well-formed wet web and has a specific large aspect ratio.
It has a specific gap diameter. Since the formation is good, the entanglement is performed uniformly and the fiber length is long, so that the nonwoven fabric has a very large strength. In addition, because the formation is uniform, the feel is good, and the texture, breathability, and strength are excellent.
It is a good non-woven fabric that could not be obtained with a conventional non-woven fabric.

[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.

As for the thickness shown in the examples, the apparent thickness was measured. The tensile strength is the maximum load value until the sample breaks when the sample with a width of 20 mm and a length of 150 mm is pulled at a span of 100 mm and a speed of 200 mm / min, in the longitudinal direction (the direction in which the web is conveyed), The measurement was made in the lateral direction (perpendicular to the transport). 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.

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 formation of the non-woven fabric was visually evaluated by holding it over the transmitted light, and was evaluated on a four-point scale of ◎: very good, 良 い good, Δ slightly poor, and x bad. The feel of the non-woven fabric was judged by the degree of the feeling of being caught on the hand and the feeling of incongruity, as seen by touching and slightly rubbing. ◎ is very good, 良 い is good, Δ is somewhat bad, and × is bad.

Example 1 A polyethylene terephthalate (PET) fiber having a fineness of 1.5 d and a fiber length of 29 mm (having a fiber diameter of 12 μm) was used as a high L / D fiber.
m, L / D = 2.4 × 10 ³ ) 85 parts, as low L / D fiber, PET fiber having the same fineness and a fiber length of 20 mm (L / D =
(1.7 × 10 ³ ) 15 parts were impregnated with a 1% nonionic dispersant solution. Then, 3 parts of hot water-soluble polyvinyl alcohol (PVA) fiber (VPW107-1, manufactured by Kuraray Co., Ltd., dissolved in hot water and then re-dissolved in water at a temperature of 20 ° C.) are dispersed in a pulper, and a reciprocating reversing stirrer ( Agitator, manufactured by Shimazaki Manufacturing Co., Ltd.)

[0074] Of the PET fibers impregnated in the dispersant, the low L / D fibers were transferred to a pulper, water was added, and the mixture was stirred at a high speed for a short time to disintegrate the fiber bundle. Then, high L / D
The fibers were charged and disintegrated similarly. This slurry was transferred to a chest, water was further added thereto, and a 0.1% solution of ultra high molecular weight polyacrylamide (viscosity agent) was mixed with gentle stirring with an agitator. Thus, a uniform slurry was prepared. Using this slurry, a width of 50
A web having a paper weight of 41 g / m ² and a basis weight of 41 cm was formed and dried at 110 ° C. using a Yankee dryer.

Two sheets were laminated, and the nozzle head was
The confounding was performed with a columnar water flow using a head. The nozzle of the first head has a nozzle diameter of 120 μm, the nozzle interval is 0.6 mm, the water pressure is 80 kg / cm ^{2 in} two rows, the second head has the nozzle diameter of 120 μm, the nozzle interval is 0.3 mm, the water pressure is 140 kg / cm ^{2 in} one row, and the third The head has a nozzle diameter of 100 μm, a nozzle interval of 0.3 mm, and a water pressure of 150 kg / cm ² in one row.

The laminated sheet was mounted on a support made of reinforced polyester and plain-woven 100 mesh, saturated in water, and then passed through the laminated sheet under the above-mentioned water flow to strongly entangle the fibers. The sheet after the entanglement was inverted, and the same processing was performed on the back surface. However, the water pressure was set at 140, 150 and 80 kg / cm ² in order from the first head. The confounding speed was 15 m / min. The entangled web was dried at 110 ° C. using a suction through dryer to obtain a nonwoven fabric. The resulting nonwoven fabric was substantially non-porous.

Example 2 PE having a fineness of 1.5 d and a fiber length of 38 mm as high L / D fiber
T fiber (fiber diameter 12 μm, L / D = 3.2 × 10 ³ ) 60
Part, low L / D fiber, same fineness and 10 mm fiber length P
Using 40 parts of ET fiber (L / D = 0.8 × 10 ³ ), a nonwoven fabric was produced in the same manner as in Example 1. Table 1 shows the results
Shown in

Example 3 PE having a fineness of 1.5 d and a fiber length of 45 mm as a high L / D fiber
15 parts of T fiber (L / D = 3.8 × 10 ³ ), PET fiber having the same fineness as low L / D fiber and having a fiber length of 10 mm (L / D
Example 1 using 70 parts of D = 0.8 × 10 ³ ) and 15 parts of PET fiber having a fiber length of 20 mm (L / D = 1.7 × 10 ³ ).
A non-woven fabric was produced in the same manner as in the above. However, the order of fiber dispersion was such that the fiber length was 10 mm, 20 mm, and 45 mm. Table 1 shows the results.

Example 4 PE having a fineness of 0.4 d and a fiber length of 20 mm as a high L / D fiber
T fiber (fiber diameter 6.5 μm, L / D = 3.1 × 10 ³ ) 5
0 parts, 50 parts of PET fiber (L / D = 1.5 × 10 ³ ) having the same fineness and a fiber length of 10 mm as the low L / D fiber,
A nonwoven fabric was manufactured in the same manner as in Example 1. Table 1 shows the results.

Example 5 PE having a fineness of 0.4 d and a fiber length of 30 mm as a high L / D fiber
T fiber (fiber diameter 6.5 μm, L / D = 4.6 × 10 ³ ) 2
0 parts, PE with 5 mm fiber length with same fineness as low L / D fiber
A nonwoven fabric was manufactured in the same manner as in Example 1 using 80 parts of T fiber (L / D = 0.8 × 10 ³ ). Table 1 shows the results.

Example 6 PET having a fineness of 4d and a fiber length of 45 mm was used as a high L / D fiber.
50 parts of fiber (fiber diameter 20 μm, L / D = 2.5 × 10 ³ ) and PET fiber having a fineness of 0.4 d and a fiber length of 10 mm as a low L / D fiber (L / D = 1.5 × 10 ³ ) Using 50 parts,
A nonwoven fabric was manufactured in the same manner as in Example 1. Table 1 shows the results
Shown in

Example 7 Disintegration and dispersion were performed using a Bellmer-type chest having a thickness of 20 mm and having round blades attached thereto with the same composition as in Example 1. After confirming that the fibers were sufficiently disintegrated, the stirring speed was reduced, and a tackifier was added to maintain a uniform dispersion state. Example 1
A nonwoven fabric was obtained in the same manner as described above. Table 1 shows the results. Good nonwoven fabrics were obtained with different dispersion methods.

Comparative Example 1 PET fiber having a fineness of 1.5 d and a fiber length of 38 mm (fiber diameter: 12
μm, L / D = 2.4 × 10 ³ ), a web was formed using a card, and the web manufactured using a cross wrapper was entangled under the same conditions as in Example 1 to manufacture a nonwoven fabric. Table 1 shows the results. Although a nonwoven fabric having a small aspect ratio was obtained, the formation was poor and the touch was rugged in some places as compared with those using a wet web having the same fiber length. These are thought to be due to uneven basis weight. Also, the difference in strength between the sample pieces was large.

Comparative Example 2 PET fiber with a fineness of 1.5 d and a fiber length of 38 mm (fiber diameter 12
μm, L / D = 3.2 × 10 ³ ) 5 parts, fiber length 1.5d,
PET fiber with a fiber length of 10 mm (L / D = 0.8 × 10 ³ )
A nonwoven fabric was manufactured in the same manner as in Example 1 using 95 parts. Table 1 shows the results. As shown in the table, L
Since / D was small and the fibers were short, the fibers fell off, the basis weight was greatly reduced, the entanglement was insufficient, and a nonwoven fabric with high strength could not be obtained. In addition, the free end of the fiber appeared on the surface layer of the nonwoven fabric, which was considered to be the cause.

Comparative Example 3 PET fiber having a fineness of 0.1 d and a fiber length of 5 mm (fiber diameter 3 μm)
m, L / D = 1.7 × 10 ³ ), and a nonwoven fabric was produced in the same manner as in Example 1. Table 1 shows the results. Since the fiber diameter is small and the L / D is small, the strength is low. Further, the pressure loss was large, and the nonwoven fabric intended by the present invention could not be obtained.

[0086]

[0087]

[0088]

[Table 1]

[0089]

[0090]

[0091]

Example 8 A polypropylene (PP) fiber having a fineness of 0.5 d and a fiber length of 20 mm (fiber diameter 8.8 μm, L / D =
2.3 × 10 ³ ) 70 parts, PP fiber having the same fineness as the low L / D fiber and having a fiber length of 10 mm (L / D = 1.1 × 1)
0 ³ ) A nonwoven fabric was produced in the same manner as in Example 1 using 30 parts. Table 2 shows the results.

Example 9 Acrylic (AN) fibers having a fineness of 0.5 d and a fiber length of 20 mm (fiber diameter 8 μm, L / D = 2.5 × 1) as high L / D fibers
0 ³ ) 20 parts, the same fineness as low L / D fiber, fiber length 1
20 parts of 5 mm AN fiber (L / D = 1.9 × 10 ³ ) and 20 parts of 7 mm long AN fiber (L / D = 0.9 × 10 ³ )
Part, AN fiber with the same fineness and a fiber length of 5 mm (L / D = 0.6
× 10 ³ ) A nonwoven fabric was produced in the same manner as in Example 1 using 20 parts. Table 2 shows the results.

[0094] Example 1 0 high L / D fiber fineness 1.5d, rayon fibers (fiber diameter 12μm, L / D = 2.1 × 10 3) of the fiber length 25 mm 1
5 parts, 85 parts of rayon fiber (L / D = 0.83 × 10 ³ ) having the same fineness as low L / D fiber and having a fiber length of 10 mm, and further 3 parts of PVA fiber (VPW107-1) were added to water,
A 0.1% solution of a high-molecular polyacrylamide (viscosity agent) was added, and the fibers were disintegrated and dispersed using a beater of Naginata. Further, the slurry was transferred to a chest equipped with an agitator, further diluted with water, a tackifier was added, and the dispersion was maintained. Papermaking and drying were performed in the same manner as in Example 1, two sheets of the obtained sheets were laminated, and entangled to obtain a nonwoven fabric. Table 2 shows the results.

Comparative Example 4 A rayon fiber 4 having a fineness of 1.5 d and a fiber length of 38 mm
^Two card webs of 0 g / m ² were laminated and entangled under the same conditions as in Example 1. Table 3 shows the results. The web obtained with the card web was poorly textured, resulting in inferior strength, drapability, and feel to those using a wet web.

[0096]

[Table 2]

[0097] Example 1 1 fineness 3d, split fibers comprising a fiber length of 5mm polyethylene, polypropylene (DF-2, Yamato Boseki Co., Ltd., 16 splittable fiber diameter 5~6μm after splitting) the nonionic dispersion Using a dispersant, the mixture is stirred with a pulper and divided, and the basis weight is 41 g / m ^2.
Web was made. This sheet and a 41 g / m ² PP fiber web of Example 10 were laminated, and entangled in the same manner as in Example 1. Entangling was performed from a layer of split fibers. Using this nonwoven fabric, the lens of eyeglasses stained with hand marks was wiped off on the side of the split fibers. The dirt is clean and no scratches on the lens. No loss of fibers was observed. It could be reused even after washing with a neutral detergent.

[0098] Example 1 2 Example 3 stacked and the resulting wet papermaking web 4, to give a basis weight 120 g / m ² nonwoven fabric under the same conditions as in Example 1. To this nonwoven fabric, a black pigment was added to a polyurethane elastomer in a 30% DMF solution at a polyurethane content of 3% based on the remaining amount of the polyurethane, and a knife coater was coated at 20 g / m ² .
Dry coagulation was performed to obtain a grainy synthetic leather. It has excellent elasticity and tactile sensation, and has a natural leather-like luster.

[0099]

According to the present invention, a fiber having a specific fiber diameter and an aspect ratio larger than a predetermined value is contained in a specific ratio or more, and these fibers are three-dimensionally entangled to have a specific void diameter, whereby formation is reduced. It is possible to obtain a nonwoven fabric which is good, has excellent drapability and tactile sensation, and has high strength. It is more preferable to use a fiber having a specific fiber length. Even if the aspect ratio and the fiber length are within the range of the present invention, those having poor formation are out of the range of the void diameter, and have poor drapability, tactile sensation and strength.

Claims (2)

(57) [Claims] 1. A nonwoven fabric in which a wet-laid paper web containing a water-soluble binder is monolayer or laminated, and fibers in the web and between layers are three-dimensionally entangled and do not substantially peel off within the monolayer or between layers. A good hydroentangled nonwoven fabric with a satisfactory texture. It consists fineness 0.3 denier or more fibers, and a ratio of fiber length within the 0.3 denier or more fibers (L) and fiber diameter (D) (L / D, aspect ratio) of greater than 2000 fibers 10 of the weight of the hydro-entangled nonwoven fabric
９０90% by weight. The value of the maximum gap diameter with respect to the average gap diameter is within 5 times. 2. A fiber having a fineness of 0.3 denier or more and an aspect ratio of 2,000 or less is dispersed in water, and then a fiber having an aspect ratio of more than 2,000 is dispersed in water or both are dispersed at the same time. Not tangled , water soluble
To prepare a slurry containing a binder, and papermaking using a wet papermaking method, the resulting web, a single layer or a plurality of stacked, or, laminated with other nonwoven fabric is placed on the support, the high pressure columnar from the seat above A method for producing a water entangled nonwoven fabric, comprising jetting a water stream, three-dimensionally tangling fibers, and drying.