JPH05214650A - Nonwoven fabric interlaced with water jet and having excellent texture and its production - Google Patents

Abstract

PURPOSE:To provide the subject nonwoven fabric containing fibers having a specific diameter and an aspect ratio higher than a specific level at a specific ratio in a three-dimensionally interlaced state, having a specific void diameter and exhibiting excellent drapeability and feeling and high strength. CONSTITUTION:The objective nonwoven fabric produced by a water-jet interlacing process contains 10-90wt.% of fiber having a fiber diameter of >=0.3d and an aspect ratio of >=2,000. The maximum void diameter of the nonwoven fabric is <=5 times the average void diameter. The length of the fiber constituting the nonwoven fabric is <=50mm. The objective process for the production of a water-jet interlaced nonwoven fabric is characterized by the production of a web by a wet paper-making process from a slurry of the above fiber prepared taking care of not to cause the entanglement of the fibers, the lamination of the webs or the web and other sheets in one or more layers and the three- dimensional interlocking of the fiber by the application of a high-pressure water jet stream to the laminate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nonwoven fabric having a good texture and excellent drape, texture, air permeability and strength, and a method for producing the same.

[0002]

2. Description of the Related Art In recent years, non-woven fabrics have been widely used in many fields in place of woven fabrics. Because of its low cost and high productivity, it can be used as a substitute for conventional woven fabrics, or can be used as a functional nonwoven fabric because it can impart performance not obtained with woven fabrics. Furthermore, conventionally, the functionality of non-woven fabrics has been utilized in the field of paper pulp as a raw material, and supply as a high-performance material has become popular.

Among them, a high pressure columnar water stream is used to produce fibers
Many so-called spunlaced nonwoven fabrics or hydroentangled nonwoven fabrics, which are dimensionally entangled and have a texture like a woven fabric, have been actively developed, and many products have been put on the market. Since the hydroentanglement (spunlace) method is one of the web processing methods, it is necessary to supply the web before processing. Examples of the web manufacturing method include a card method, a dry method such as an air laid method, a melt blow method, a spun bond method, and a wet papermaking method.

The card method can use fibers having a long fiber length, but it is difficult to form a uniform web, and the nonwoven fabric obtained by being processed by a high-pressure columnar water flow also has a poor texture and is observed by transmitted light. There are spots, leaving problems in terms of texture and texture. In the air lay method, the texture is deteriorated when a fiber having a long fiber length is used, and the obtained nonwoven fabric has a problem in terms of feel and texture.

When a web obtained by the spunbond method is used,
Despite its high strength, it is not well formed and the fibers are continuously connected. There are few free ends of the fibers, and three-dimensional entanglement requires a large amount of energy, and complex formation by mutual entanglement with other webs. Is difficult. In the melt blow method,
Although fine fibers can be made into a web, there are problems that the formation is poor, the production rate is slow, the strength is weak, and the cost is high.

The wet papermaking method has a higher production speed than the above-mentioned method, and a plurality of fibers having different fineness and kinds can be mixed in an arbitrary ratio in the same apparatus. In other words, the fibers can be selected in a wide range of choices such as staple and pulp, and the usable fiber diameters can be varied from so-called ultrafine fibers to thick fibers, which is extremely better than other methods. Is the way to get the web. From this, it is considered that the web forming method has an extremely wide range of applications.

In the method disclosed in Japanese Patent Laid-Open No. 2-6651, the fiber diameter is 7 to 25 μm, and the ratio of the fiber diameter (D) to the fiber length (L) (L / D, aspect ratio) is 800 to 2.
000 short fiber webs are three-dimensionally entangled by a high-pressure columnar water flow to disclose a wet nonwoven fabric.

[0008] This non-woven fabric is noted as an improvement over the drawback of the conventional non-woven fabrics, which is the weakness due to the short fiber length. That is, in the hydroentangled nonwoven fabric using the wet web in the above aspect ratio range, there are many free cutting ends of the fibers, there are many fibers that can move freely during the entanglement, and many fibers are uniformly entangled. Therefore, it is said that the strength is exhibited.

However, among the prior art in this specification,
In order to uniformly disperse the fibers in water, a fiber length of about 3 to 7 mm is generally required, and it is stated that a nonwoven fabric obtained by processing a wet web having a fiber length of more than 7 mm has a poor texture.
Further, as shown in Comparative Example 2, it is said that the entanglement of fibers in the slurry state is a cause of deterioration of drape property of the nonwoven fabric after entanglement and insufficient strength.

Similarly, as an example of using a wet papermaking web, JP-A-3-14695 describes that a preferable fiber length is 15 mm or less. Here, as shown in Comparative Example 1, fibers are used. It is considered that the fiber is entangled and the texture is deteriorated, rather than the fact that the length becomes longer and the entanglement becomes difficult, and the strength is decreased.

From the above, the aspect ratio becomes large and the movement of the fiber during the entanglement is suppressed.
It can be considered that the performance such as the drape property and the strength of the non-woven fabric was deteriorated because the formation was deteriorated and the movement of the fiber was suppressed.

On the other hand, when the web by the dry method, particularly the card method is used, the preferable fiber length is 20 to 100 mm. In the case of the card method, a fiber having a suitable free cut end and having a long fiber length (effectively used for entanglement) can be used. Therefore, it is considered that the fiber length is longer than that of the wet method in addition to the strength simply by the entanglement, and the range of the entanglement of one fiber is wide and the strength is exhibited.

[Problems to be Solved by the Invention]

The present invention makes use of the advantages of a wet papermaking method and a dry web, and produces a web having a good texture and a long fiber length by the wet papermaking method, and using this, high strength, drapability,
The object is to provide a uniform non-woven fabric having a good texture and good breathability.

[0014]

Means for Solving the Problems The present inventors have diligently studied the above problems. As a result, it is produced from the wet papermaking web and contains fibers having a fineness of 0.3 denier (hereinafter abbreviated as d) or more, and these fibers have a specific aspect ratio and are three-dimensionally entangled, resulting in specific voids. By having a diameter,
It has been found that a non-woven fabric having a good texture and excellent strength, drape, texture, and breathability can be obtained. Further, they have found that a fiber having a specific aspect ratio is carefully paper-made by a wet paper-making method to produce a web having a good texture, and the non-woven fabric can be produced by three-dimensionally interlacing.

That is, the present invention satisfies the following conditions in a nonwoven fabric in which a wet papermaking web is formed into a single layer or laminated, fibers in the web and between layers are three-dimensionally entangled, and substantially no separation occurs in the single layer or between layers. It is a hydroentangled nonwoven fabric with a good texture. Made of fibers with a fineness of 0.3 denier or more, and 0.3
Fiber length (L) and fiber diameter (D) among denier fibers and above
A fiber having a ratio (L / D, aspect ratio) of more than 2000 is contained in an amount of 10 to 90% by weight based on the weight of the hydroentangled nonwoven fabric. The value of the maximum void diameter with respect to the average void diameter is within 5 times. The nonwoven fabric is a hydroentangled nonwoven fabric having a fiber length of 50 mm or less.

Fibers having a fineness of 0.3 denier or more and an aspect ratio of 2000 or less are dispersed in water, and then fibers having an aspect ratio of more than 2000 are dispersed in water, or both of them are dispersed at the same time. A slurries that do not get entangled are prepared, papermaking is performed using a wet papermaking method, and the obtained web is laminated in a single layer or a plurality of layers, or is laminated with other non-woven fabric, placed on a support, and the high-pressure columnar water flow is applied from above the sheet. Is sprayed, the fibers are entangled three-dimensionally, and the fibers are dried, which is a method for producing a hydroentangled nonwoven fabric having a good texture.

The present invention will be described in detail below. Also,
The hydroentangled non-woven fabric having a good texture is hereinafter abbreviated as non-woven fabric in the text. The fibers used in the nonwoven fabric of the present invention have a fineness of 0.3 d or more. More preferably 0.3 to 5
It is d. If it is thinner than 0.3d, the strength is weak in consideration of the field of use of the nonwoven fabric of the present invention, and it is also dense and poor in air permeability, which is not preferable. When it exceeds 5 d, the fiber diameter is large and the surface property of the nonwoven fabric is deteriorated, which is not preferable. Further, as will be described later, in the aspect ratio range of the present invention, the fiber length becomes very large, and it is difficult to fabricate a web having a good texture.

It is preferable to use fibers having an aspect ratio of more than 2000 in a specific ratio. Other than this fiber, those of 2000 or less are used. Hereinafter, a fiber having an aspect ratio of more than 2000 is a high L / D fiber, 20
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 content is less than 5% by weight, not only the strength of the non-woven fabric is weak, but also many cut ends of the fiber are exposed on the non-woven fabric surface, resulting in poor touch.

When the high L / D fiber is contained in an amount of 10% by weight or more, the strength of the non-woven fabric is increased and the touch is improved. It is considered that this is because not only the entanglement between the high L / D and 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 fibers are 10-9 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 a fiber longer than 50 mm is mixed with a low L / D fiber, the fiber is entangled and papermaking is difficult.

The reason for using the high L / D fiber and the low L / D fiber will be described in more detail. It is considered that the strength of the nonwoven fabric obtained by the hydroentanglement method is determined by the balance of the entangled state, the fiber length and the aspect ratio. However, considering that the good fiber length for entanglement in the case of the dry method is 20 to 100 mm, the longer fiber length and the larger aspect ratio are within the fiber length and aspect ratio ranges of the present invention. The strength of the non-woven fabric is increased. In the range of the fiber length, the reason why the strength is lowered despite the fact that the fiber length has a large aspect ratio is that the texture of the web is lowered.

Generally, the shorter the fiber length, the more free ends of the fiber and the more entanglement between the fibers, but since the fiber is short, the fibers that can be entangled are limited to the fibers very close to the fiber. On the other hand, when the fiber length is long, the free ends are small, but since the fiber length is long, the range of fibers that can be entangled is wide.
Thus, the degree of entanglement depends on the fiber length and the free end. However, since the fiber length of 20 mm or more is effective in the dry web, it is considered that the strength difference due to the difference in the fiber length is larger than the strength difference due to the difference in the number of the free ends of the fibers.

In addition to the above, if the fibers are more likely to move during the entanglement, the entanglement is easier and the strength of development is greater. It is considered that the mobility of the fibers is greatly influenced by not only the aspect ratio of the fibers but also the fiber arrangement of the web, that is, the formation. That is, the aspect ratio is 2
Even if it exceeds 000, a better nonwoven fabric can be obtained if the web has a good texture. On the other hand, in the case of a poorly formed web, the movement of the fibers is suppressed, so that the strength is not expressed for the fiber length.

For the above reasons, the aspect ratio is 2000.
In the case of using only the following fibers, since the fiber length of the fibers used is short, a nonwoven fabric having good formation and a certain strength can be obtained, but it cannot be said to be sufficient. It is believed that the inclusion of fibers greater than 2000, i.e., high L / D fibers, results in a better nonwoven fabric.

However, if the aspect ratio exceeds 5000 or the fiber length exceeds 50 mm,
At the current technical level, wet papermaking is difficult, the formation of the web is deteriorated, free movement of fibers is suppressed, and entanglement cannot be performed firmly. Because there is such a weak part of confounding,
On the contrary, not only the strength is deteriorated, but also the non-woven fabric is impaired in uniformity due to the entanglement unevenness and the texture is deteriorated, so that the texture, the drape property and the like are deteriorated.

In the present invention, it has been found that by incorporating a low L / D fiber into a high L / D fiber, a hydroentangled nonwoven fabric having high strength and good texture can be obtained. High L / D
Although it is possible to disperse fibers only, care must be taken in disaggregation and dispersion so that the fibers do not become entangled. That is, it was necessary to pay attention to the shear applied to the fiber during disaggregation and the stirring state after dispersion, and it was necessary to reduce the dispersion concentration.

In the present invention, by mixing the high L / D fibers with the low L / D fibers in a specific ratio, the high L / D fibers are less likely to be entangled, and the dispersion is facilitated and the dispersion state is improved. A stable and well-formed web can be manufactured.
The hydroentangled non-woven fabric using this web has good texture and high strength. That is,
By using the low L / D fiber, not only the dispersion concentration can be increased, but also the low L / D fiber penetrates between the fibers of the high L / D fiber to stabilize the dispersion state. Further, even if the low L / D fiber is contained, a nonwoven fabric having high strength can be obtained within the range of the present invention.

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

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

The polyolefin fibers are fibers made of homopolymers and copolymers of polypropylene, polyethylene, polystyrene, modified polymers thereof, etc.
Polyacrylonitrile-based fibers are acrylic fibers, modacrylic fibers, etc., polyvinyl alcohol-based fibers are fibers made of polyvinyl alcohol, and nylon fibers are fibers made of polymers such as nylon 6 and nylon 66.

Semi-synthetic fibers are fibers such as acetate fibers,
The regenerated fiber means a regenerated cellulose fiber such as rayon or a solution of collagen, alginic acid, chitin and the like, which is spun. Natural fibers refer to cellulosic fibers such as hemp and cotton, and protein fibers such as wool and silk.

In the case of synthetic fibers, the fibers used in the present invention may be in the form of composite fibers composed of two or more kinds of the above polymers. The cross-sectional shape of the fiber is not only circular or elliptical but also triangular, Y-shaped, T-shaped, U-shaped, star-shaped,
It may have a so-called atypical cross-sectional shape such as a dog bone type.

The fibers having a fineness of 0.3 d or more used in the present invention have a relatively low rigidity, so that the fibers are more likely to move and bend, and entanglement is easier. In the case of a fiber with a small aspect ratio, a fiber with a relatively large rigidity is a fiber that moves, but it is difficult to bend or twist the fiber, and it tends to fall off the web rather than the entanglement of the fiber, and it is not suitable for entanglement. is there.

However, the high L / D fiber can be bent even if it has a high rigidity, and can be entangled if it is entangled at a higher water pressure. In addition, a web containing high L / D fibers also has an unexpected effect of suppressing the loss of low L / D fibers. By using a web in which fibers are fixed with a binder component that causes dissolution or contact separation during the process of entanglement, entanglement can be performed at higher water pressure.

Naturally, in addition to the above fibers, a small amount of fibers other than those limited by the present invention can be contained in the non-woven fabric, but it should not be in the range of impairing the performance of the non-woven fabric of the present invention.

Next, the void diameter of the nonwoven fabric of the present invention will be described. The void diameter is measured as the maximum void diameter and the average void diameter by the bubble point method and the 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. These void sizes change depending on the degree of entanglement. For example, when the entanglement is strongly performed, the void diameter of these is small, and conversely, when the entanglement is weak, the void diameter is large. That is, formation,
If the entanglement is uneven due to the fluctuation of the basis weight, the distribution range of the void diameter becomes wide. It cannot be judged that the confounding was effectively performed because the average of the void diameters showed a specific value. Therefore, it can be considered that the smaller the difference between the average void diameter and the maximum void diameter, the more uniform the nonwoven fabric, in other words, the more uniform the entanglement.

When the maximum void diameter is within 5 times the average void diameter, it is confirmed that the fibers are uniformly entangled. When the maximum void diameter exceeds 5 times the average void diameter, the nonwoven fabric lacks uniformity, is poorly textured, has uneven entanglement, is poor in nonwoven fabric strength, and is inferior in drapeability and touch to the skin. .. Thus, the maximum of non-woven fabric,
By measuring the average void diameter, the entangled state, the texture of the nonwoven fabric,
It is possible to evaluate not only the uniformity but also the texture and drape derived from these.

Next, the method for producing the nonwoven fabric of the present invention will be described. The fibers used in the present invention have a large aspect ratio, and it is necessary to pay particular attention so that the fibers do not become entangled during the disaggregation and dispersion steps. As described above, the deterioration of the formation due to the entanglement of fibers in the web obtained by the wet papermaking 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 dispersed state of the slurry is stably and favorably maintained.

When the disintegration of the high L / D fibers is relatively easy, there is no particular limitation on the order of mixing the fibers into water, but when the disintegration is difficult and the fibers are easily entangled, the fibers having a smaller aspect ratio are used. It is more difficult for the fibers to become entangled when the fibers are added in order. It is considered that the low L / D fibers dispersed earlier enter the high L / D fiber intervals that are disaggregated and dispersed.

A method of uniformly dispersing a dispersant in an aqueous solution before disaggregating the fibers or pre-immersing the fibers in a solution of about 1% dispersant accelerates disaggregation of the fibers. Above, it is preferable, and it is effective in preventing entanglement after disaggregation. For disaggregation and dispersion, it is possible to use a rotary type. 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 easily clinging to each other, a thick type is preferable to a case where fibers having a small aspect ratio are dispersed. Furthermore, it has a thickness of 1/3 or more of the fiber length of the longest fiber,
A rounded one is preferable.

Regarding the stirring, it is preferable that the stirring for disaggregation is carried out promptly because the fibers are not entangled.
If the disaggregation of the fibers is insufficient with a short time of stirring, the stirring speed is momentarily increased to impact the undisaggregated fiber bundle,
A method of promoting disaggregation is preferred. The agitation speed is only temporarily increased, and if the agitation 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 speeding the stirring again for a short time. Further, it is also effective to treat the undisintegrated fiber for a short time with a beater for the purpose of intermittently giving a share.

Next, when the disaggregated fibers are dispersed, in order to prevent the fibers from becoming entangled, the dispersion of the fibers is maintained and the stirring is performed under the gentlest possible stirring. If necessary, further water is added to the previously disaggregated slurry to reduce the concentration, and then a viscous agent is rapidly added to maintain the dispersion. During this period, stirring is performed as gently as possible as described above. In this way, a uniformly dispersed slurry is prepared. The term "uniform" here means a state in which entanglement or flocculation of fibers is not substantially observed during stirring.

The slurry thus prepared can be formed into a web by a wet papermaking method. This web may be continuously three-dimensionally entangled with a high-pressure water stream.
Further, a binder is applied to the web, and after the papermaking, it is dried,
After winding once, three-dimensional entanglement may be performed. The binder is preferably applied in the slurry in the case of a fibrous material, and in the case of a liquid in the method of applying after the papermaking and before drying. As a method for drying the web, a Yankee dryer, a multi-cylinder cylinder dryer, an air dryer, or the like can be used, and the web can be dried by an ordinary drying method.

The binder used here may be liquid or fibrous. As the fibrous material, there are one that utilizes the entanglement with the main fiber and one that utilizes the adhesiveness with the fiber by heat or the like.

As the liquid, those which are dissolved in the process of entanglement are preferable. Therefore, water-soluble ones are preferable. Further, a method in which these water-soluble binders are made into a fibrous shape and paper-making with the main fiber is also a preferable method. The amount of liquid binder applied is 1 to 10 with respect to the weight of the sheet.
Weight percent 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 adhesion between fibers is too strong, and it is difficult to cut the adhesion and perform new three-dimensional entanglement. Therefore, when the layers are laminated, the entanglement between the layers is weak and delamination occurs.

The fibrous binder is preferably one in which the bond with the main fiber is separated in the course of the entanglement and a new three-dimensional entanglement is developed.

For this reason, the amount of the binder applied is preferably 3 to 20% by weight based on the weight of the sheet in the case of an adhesive material. If it is less than 3% by weight, the strength after papermaking cannot be obtained. If it exceeds 20% by weight, the movement of fibers is suppressed,
The confounding cannot be done firmly. Moreover, after lamination, delamination occurs.

In the case of utilizing the entanglement with fibers, when the structure has a branched structure and the branched portion has the fineness and 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 preferred.

When the sheet using the binder is entangled, the texture is not disturbed in this step, and a nonwoven fabric having a good texture can be obtained. It is presumed that entanglement occurs immediately after the adhesive is released.

Using the web or sheet thus obtained, three-dimensional entanglement is performed with a high-pressure columnar water stream. As 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 fibers.

The conditions for strong and proper interlacing 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 distance between the nozzles is preferably 10 to 1500 μm.

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

Water pressure is preferably used in the range of 10 to 250 kg / cm ² . More preferably 50-250 kg /
It is in the range of cm ² . If it is less than 10 kg / cm ² , sufficient fiber entanglement cannot be obtained. If it is more than 250 kg / cm ^2, the fibers are significantly detached from the web and the sheet is broken. However, it should be additionally noted that the upper limit of the interlaced water pressure varies 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 was effective in terms of strength to perform entanglement with a pressure of 140 kg / cm ² from at least one row of nozzles.

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

By arranging the nozzles in stages and gradually increasing the water pressure from the initial stage to the final stage of processing, damage to the web can be reduced and proper entanglement can be performed. It is also preferable in that the surface quality is improved. Similarly, it is preferable to sequentially reduce the nozzle diameter or the nozzle interval, or both, from the viewpoint that the entanglement can be appropriately performed and the surface quality of the nonwoven fabric is improved.

Further, the surface quality can be further improved by rotating the header of the nozzle, oscillating to the left or right, or oscillating the supporting wire of the web to the left or right. Further, after the entanglement, a wire mesh of 40 to 100 mesh is inserted between the nozzle and the web, and the columnar water stream is sprinkled to spray the web to improve the surface quality.

As the confounding method, only one side or both sides can be confounded. It is also possible to further entangle by laminating webs and the like after the entanglement.

The web thus obtained, which has been subjected to the three-dimensional entanglement treatment, removes excess water by a method such as suction or wet pressing during or after the entanglement, and then, an air dryer, an air through dryer, or Drying can be performed using a suction drum dryer or the like.

The non-woven 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 web after the entanglement in whole or in part. However, when it is necessary to obtain a softer non-woven fabric, it is necessary to dry the nonwoven fabric below the melting point of the binder.

Of course, other non-woven fabrics such as dry non-woven fabrics, pulp sheets, wet non-woven fabrics containing fibers which fall outside the scope of the claims of the present invention can be entangled with one side, both sides or a sandwich, but this It goes without saying that it should not be in a range that hinders the object of the invention.

The spunlaced nonwoven fabric of the present invention having a good texture obtained by the above method can be subjected to post-treatments such as bending, resin impregnation and water repellent treatment. Performance can be imparted.

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

Since it has good air permeability, it is suitable for use as a prefilter for liquids and gases.

Further, since it has a good texture and a good texture, it is suitable for use as a base material for synthetic leather and can be impregnated with an elastic polymer. Further, when three-dimensionally entangled, webs made of so-called ultrafine fibers having a fineness are laminated and entangled, which is suitable for use as a base material for high-grade suede-like artificial leather. Above, examples of the use of the non-woven fabric of the present invention have been shown, but it should be noted that the use is not limited to these.

[0068]

The nonwoven fabric of the present invention uses a wet web having a good texture and has a specific large aspect ratio.
It has a specific void diameter. Since the texture is good, the entanglement is performed uniformly, and the fiber length is long, so that the nonwoven fabric has a very high strength. In addition, since the texture is uniform, it feels good to the touch, has excellent texture, breathability, and strength.
It is a good non-woven fabric that cannot be obtained with conventional non-woven fabrics.

[0069]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.
All parts and percentages mentioned in the examples are by weight.

The thickness shown in the examples is an apparent thickness. Tensile strength is the maximum load value until a sample breaks when a 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 (direction in which the web is conveyed), The lateral direction (the direction perpendicular to the conveyance) was measured. 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 velocity of 5.3 cm / sec according to JIS-B9908 type 1 was determined. 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 texture of the non-woven fabric was evaluated by visually observing the one held over the transmitted light, and evaluated in four grades of "Excellent", "Good", "Fair" and "Poor". The texture of the non-woven fabric was judged by the texture and a little rubbing, and it was judged by the degree of being caught on the hand or feeling uncomfortable. ⊚ is very good, ○ is good, Δ is slightly bad, and × is bad.

Example 1 Polyethylene terephthalate (PET) fiber having a fineness of 1.5 d and a fiber length of 29 mm as a high L / D fiber (fiber diameter 12 μm
m, L / D = 2.4 × 10 ³ ) 85 parts, as a low L / D fiber, PET fiber having the same fineness and a fiber length of 20 mm (L / D =
15 parts of 1.7 × 10 ³ ) was impregnated in 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 20 ° C.) was dispersed in a pulper in an amount of 3 parts, and a reciprocating reversing stirrer ( Moved to a chest equipped with Agitator, Shimazaki Seisakusho.

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 high speed for a short time to disaggregate the fiber bundle. Then, high L / D
Fiber was added and disaggregation was performed in the same manner. The slurry was transferred to a chest, water was further added thereto, and a 0.1% solution (adhesive) of ultra-high molecular weight polyacrylamide was mixed while gently stirring with an agitator. In this way, a uniform slurry was prepared. A width of 50 with a cylinder paper machine using the slurry.
A web having a cm and a basis weight of 41 g / m ² was made and dried at 110 ° C. using a Yankee dryer.

Two sheets were laminated and three nozzle heads were used.
Entangling was performed with a columnar water flow using the head. The nozzle of the first head has a nozzle diameter of 120 μm, the nozzle spacing is 0.6 mm, the water pressure is 80 kg / cm ² in the second row, and the second head has a nozzle diameter of 120 μm, the nozzle spacing is 0.3 mm, the water pressure is 140 kg / cm ² in the first row, and the third The head has a nozzle diameter of 100 μm, a nozzle spacing of 0.3 mm, and a row of water pressure of 150 kg / cm ² .

The laminated sheet was placed on a 100-mesh support made of reinforced polyester and plain-woven, and after saturating in water, the laminated sheet was passed under the above water flow to strongly entangle the fibers. The sheet after the entanglement was turned over and the back surface was subjected to the same treatment. However, the water pressure was 140, 150 and 80 kg / cm ² from the first head in order. The entanglement speed was 15 m / min. This 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 the high L / D fiber
T fiber (fiber diameter 12 μm, L / D = 3.2 × 10 ³ ) 60
Part, low L / D fiber, P with the same fineness and a fiber length of 10 mm
A nonwoven fabric was produced in the same manner as in Example 1 using 40 parts of ET fiber (L / D = 0.8 × 10 ³ ). The results are shown in Table 1.
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 ), the same fineness as low L / D fiber, and PET fiber of 10 mm fiber length (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 nonwoven fabric was produced in the same manner as in. However, the order of fiber dispersion was such that the fiber length was 10 mm, 20 mm, and 45 mm. The results are shown in Table 1.

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 fibers (L / D = 1.5 × 10 ³ ) having the same fineness and a fiber length of 10 mm are used as low L / D fibers,
A non-woven fabric was produced in the same manner as in Example 1. The results are shown in Table 1.

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
PE with the same fineness as 0 part, low L / D fiber and fiber length of 5 mm
A nonwoven fabric was produced in the same manner as in Example 1 using 80 parts of T fiber (L / D = 0.8 × 10 ³ ). The results are shown in Table 1.

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

Example 7 The same composition as in Example 1 was used to carry out disaggregation and dispersion using a Bellmer type chest having a wall thickness of 20 mm and equipped with round blades. After confirming that the fibers were sufficiently disaggregated, the stirring speed was reduced and a sticky agent was added to maintain a uniform dispersed state. Example 1
A non-woven fabric was obtained in the same manner as in. The results are shown in Table 1. Good nonwovens 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 ) was formed into a web using a card, and the web produced using a cross wrapper was entangled under the same conditions as in Example 1 to produce a nonwoven fabric. The results are shown in Table 1. Although a non-woven fabric having a small aspect ratio could be obtained, it was found that the texture was poor and the texture was uneven in some places as compared with the case where a wet web having the same fiber length was used. It is considered that these are due to uneven basis weight. The strength difference between the sample pieces was also large.

Comparative Example 2 PET fiber having 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 produced in the same manner as in Example 1 using 95 parts. The results are shown in Table 1. As shown in the table, L
Since / D was small and the fiber was short, the fiber fell off, the basis weight was greatly reduced, the entanglement was insufficient, and a strong nonwoven fabric could not be obtained. In addition, there was a tingling sensation that was probably due to the fact that the free ends of the fibers appeared on the surface layer of the nonwoven fabric.

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 ) was used to manufacture a nonwoven fabric in the same manner as in Example 1. The results are shown in Table 1. Since the fiber diameter is small and the L / D is small, the strength is small. In addition, the pressure loss was large, and it was not possible to obtain the nonwoven fabric targeted by the present invention.

Comparative Example 4 With the same composition as in Example 1, stirring for disaggregation was performed without using a dispersant. A viscous agent was added to this, and dispersion was performed with an agitator, but fibers were entangled in the slurry, and the fibers were entangled with each other to form a large lump. Using this slurry, papermaking and entanglement were performed under the same conditions as in Example 1. The results are shown in Table 1. Even if the same fiber was used, it was inferior to Example 1 in terms of strength, bending resistance, texture, and touch. Poor formation due to fiber entanglement is considered to be the cause.

Comparative Example 5 20 parts of PET fiber having a fineness of 2d and a fiber length of 76 mm (fiber diameter 14 μm, L / D = 5.4 × 10 ³ ) as high L / D fiber,
Example 1 Using 80 parts of PET fiber (L / D = 1.1 × 10 ³ ) having the same fineness and a fiber length of 15 mm as the low L / D fiber, Example 1
Papermaking was performed and entanglement was performed in the same manner as in. The results are shown in Table 1. I tried to get a good web, but high L / D
Tangles of the fibers frequently occurred during the disaggregation of the fibers, and the entanglement appeared as it was on the web when the tackifier was added. The web entangled using this web is not only the texture but also the strength, drape,
The touch was very bad.

[0088]

[Table 1]

Example 8 The PET fiber of Example 1 was used. However, the PVA fiber is a core-sheath type PET heat-fusible fiber (fineness 2 denier, fiber length 5).
mm, manufactured by Unitika, Melty 4080, sheath melting point 11
(0 ° C.) and changed to 10 parts to make a web having a basis weight of 40 g / m ² . A non-woven fabric was manufactured in the same manner as in Example 1 below.
However, the drying temperature after entanglement was 95 ° C. The results are shown in Table 2. Even with the heat-fusible fiber, a good non-woven fabric was obtained as in Example 1.

Example 9 Only the PET fiber of Example 1 was used, a binder was not used, a web having a basis weight of 80 g / m ² was made into paper, and entanglement was performed as it was under the same conditions as in Example 1 to produce a nonwoven fabric. .. However, the water pressure used for confounding the tables is 60, 100, 12 in order.
It was set to 0 kg / cm ² . The back side was the same as in Example 1. The results are shown in Table 2. A good non-woven fabric was obtained even when no binder was used.

[0091]

[Table 2]

Example 10 Polypropylene (PP) fiber having a fineness of 0.5d and a fiber length of 20 mm as a high L / D fiber (fiber diameter 8.8 μm, L / D =
2.3 × 10 ³ ) 70 parts, PP fiber having the same fineness as a low L / D fiber and a fiber length of 10 mm (L / D = 1.1 × 1)
0 ³⁾ with 30 parts, in the same manner as in Example 1 to produce a nonwoven fabric. The results are shown in Table 3.

Example 11 Acrylic (AN) fiber having a fineness of 0.5d and a fiber length of 20 mm as a high L / D fiber (fiber diameter 8 μm, L / D = 2.5 × 1)
0 ³ ) 20 parts, fiber length 1 with the same fineness as low L / D fiber
20 parts of 5 mm AN fiber (L / D = 1.9 × 10 ³ ) and 20 mm AN fiber (L / D = 0.9 × 10 ³ ) 20 mm
Part, AN fiber with the same fineness and fiber length of 5 mm (L / D = 0.6
A non-woven fabric was produced in the same manner as in Example 1 using 20 parts of × 10 ³ ). The results are shown in Table 3.

Example 12 Rayon fiber having a fineness of 1.5 d and a fiber length of 25 mm as a high L / D fiber (fiber diameter 12 μm, L / D = 2.1 × 10 ³ ) 1
5 parts, 85 parts of rayon fibers (L / D = 0.83 × 10 ³ ) having the same fineness as the low L / D fibers and a fiber length of 10 mm were further added with 3 parts of PVA fibers (VPW107-1) in water,
A high-molecular polyacrylamide (sticky agent) 0.1% solution was added, and fibers were disaggregated and dispersed using a naginata type beater. Further, this slurry was transferred to a chest equipped with an agitator, further diluted with water, and a viscous agent was added to maintain the dispersion state. Papermaking and drying were performed in the same manner as in Example 1, and two sheets obtained were laminated and entangled to obtain a nonwoven fabric. The results are shown in Table 3.

Comparative Example 6 4 made of rayon fiber having a fineness of 1.5 d and a fiber length of 38 mm
^Two 0 g / m ² card webs were laminated and entangled under the same conditions as in Example 1. The results are shown in Table 3. The web obtained from the card web had a poor texture and, as a result, was inferior in strength, drape and touch to those obtained using the wet web.

[0096]

[Table 3]

Example 13 Dividable fibers (DF-2, manufactured by Daiwabo Co., Ltd., 16-dividable, fiber diameter after division 5 to 6 μm) made of polyethylene and polypropylene with a fineness of 3 d and a fiber length of 5 mm were used as a nonionic dispersant. Using a pulper, stir with a pulper to divide, basis weight 41 g / m ²
The web was made into paper. This sheet and a 41 g / m ² web of PP fiber of Example 10 were laminated and entangled in the same manner as in Example 1. Entangling was done from layers of split fibers. This non-woven fabric was used to wipe the lens of eyeglasses soiled with hand dust on the side of the split fibers. The stains are cleanly removed and no scratches are visible on the lens. There was no fiber loss. It was also reusable after washing with a neutral detergent.

Example 14 Three wet papermaking webs obtained in Example 4 were laminated to obtain a nonwoven fabric having a basis weight of 120 g / m ^{2 under} the same conditions as in Example 1. To this non-woven fabric, a black pigment was added to a polyurethane elastomer of a 30% DMF solution in an amount of 3% with respect to the residual amount of polyurethane, and the knife coater was coated to 20 g / m ² ,
It was possible to obtain a synthetic leather having a grainy surface by dry coagulation. It is highly elastic and has excellent tactile sensation, and has a natural leather-like luster.

[0099]

EFFECTS OF THE INVENTION A fiber having a specific fiber diameter and an aspect ratio larger than a certain value is contained in a specific ratio or more, and these fibers are three-dimensionally entangled and have a specific void diameter, whereby the formation is improved. It is possible to obtain a non-woven fabric which is good, has excellent drapeability and touch, and has high strength. It is further preferable to use fibers having a specific fiber length. Even if the aspect ratio and the fiber length are within the range of the present invention, those having a poor texture are out of the range of the void diameter, and the drape property, the touch and the strength are also inferior.

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Claims (3)

[Claims] 1. A non-woven fabric in which a wet papermaking web is single-layered or laminated, fibers in the web and between layers are three-dimensionally entangled, and substantially no separation occurs in the single-layer or between the layers, and the fabric satisfies the following conditions. Good hydroentangled nonwoven fabric. Made of fibers with a fineness of 0.3 denier or more, and 0.3
Fiber length (L) and fiber diameter (D) among denier fibers and above
A fiber having a ratio (L / D, aspect ratio) of more than 2000 is contained in an amount of 10 to 90% by weight based on the weight of the hydroentangled nonwoven fabric. The value of the maximum void diameter with respect to the average void diameter is within 5 times. 2. The hydroentangled nonwoven fabric according to claim 1, wherein the fiber length is 50 mm or less. 3. A fiber having a fineness of 0.3 denier or more and an aspect ratio of 2000 or less is dispersed in water, and then a fiber having an aspect ratio of more than 2000 is dispersed in water, or both are dispersed at the same time to obtain these fibers. A slurries that do not get entangled are prepared, papermaking is performed using a wet papermaking method, and the obtained web is laminated in a single layer or a plurality of layers, or is laminated with other non-woven fabric, placed on a support, and the high-pressure columnar water flow is applied from above the sheet. Is sprayed, the fibers are three-dimensionally entangled and dried, and a hydroentangled nonwoven fabric is produced.