JP4849820B2 - Water-absorbing nonwoven fabric - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a thermoplastic nonwoven fabric having water absorption, and particularly relates to significant improvement in water absorption and water retention characteristics of a thermoplastic nonwoven fabric.

Conventionally, non-woven fabrics made of general-purpose thermoplastic polymers such as polyamide, polyester, and polypropylene have been known as materials for sanitary materials, general life-related materials, agricultural materials, and industrial materials. And poor water absorption. In the past, various proposals have been made to impart water absorbency to these synthetic nonwoven fabrics.
Specifically, a method of covering the surface of a synthetic fiber with a hydrophilic substance (for example, Patent Document 1), a method of attaching an alkyl phosphate metal salt (for example, Patent Document 2), a method of changing the surface or cross-sectional shape of the fiber (For example, Patent Document 3), a method for imparting porosity to a fiber (for example, Patent Document 4), a method using a water-absorbing polymer and a water-absorbing fiber (for example, Patent Document 5), a polyalkylene oxide modified product or this metamorphosis Examples include a method using a core-sheath type mixed fiber having a mixture with polyamide or polyester as a sheath component (Patent Document 6).

However, the method of covering the synthetic fiber with a hydrophilic substance and the method of attaching an alkyl phosphate metal salt are excellent in initial hydrophilicity but do not exhibit sufficient performance in terms of water absorption and water retention.
Although the method using a water-absorbing polymer and water-absorbing fiber is excellent in water absorption, it is generally difficult to obtain a high-strength material because it is a nonwoven fabric laminate with a water-absorbing polymer.
The method of changing the surface or cross-sectional shape of the fiber and the method of imparting porosity have problems such as being disadvantageous in terms of cost because it requires post-processing and a special manufacturing method.

In addition, the method using a modified polyalkylene oxide is excellent in water absorption, but has poor dimensional stability, and the modified polyalkylene oxide has poor spinnability, a core-sheath fiber structure and other thermoplastic properties. There is a problem that fiber formation is difficult unless the fiber is mixed with resin.
On the other hand, as a nonwoven fabric having water absorbency, a so-called spunlace nonwoven fabric is known in which natural fibers such as cotton and hemp are entangled and integrated, but this nonwoven fabric has low strength and the fibers themselves are not thermoplastic. It was achieved, the processing method is limited on the occasion to achieve a nonwoven fabric.

Japanese Patent Laid-Open No. 2002-348779 JP-A-8-181678 JP 2001-271228 A JP 2000-290832 A JP-A-8-120550 JP-A-11-191663

  The present invention provides a thermoplastic non-woven fabric that is difficult to impart significant water absorption and water retention, and does not require post-processing, is advantageous in terms of cost, is easy to manufacture, and does not impair practical strength. An object of the present invention is to provide a thermoplastic water-absorbing nonwoven fabric capable of imparting water absorption and water retention.

As a result of intensive studies to solve the above-described problems, the present inventors have been able to obtain a water-absorbing nonwoven fabric having dramatically improved water absorption by using a specific thermoplastic water-absorbing resin. That is, according to the present invention, there is provided a water-absorbent nonwoven fabric that consists of water-absorbent fibers which polyalkylene glycol copolymerized thermoplastic water-absorbent resin contained in the range of 30 to 70 wt%, the thermoplastic water Copolymer is a copolymer of polyester and polyethylene glycol whose main component is polytetramethylene terephthalate, and the copolymerization amount of polyethylene glycol is 5 to 90 wt.
%, A water-absorbing fiber obtained by a composite or blend of a thermoplastic water-absorbing resin and a thermoplastic resin, and the water-absorbing nonwoven fabric is formed by a spunbond method. A water-absorbing nonwoven fabric is provided.

  In the water-absorbing nonwoven fabric, the water-absorbing resin is a copolymer of polyester and polyethylene glycol mainly composed of polytetramethylene terephthalate, and the copolymerization amount of polyethylene glycol is preferably 5 to 90% by weight, preferably A range of 10% to 80% by weight is suitable. The fiber constituting the water-absorbing nonwoven fabric is a fiber obtained by combining or blending a thermoplastic water-absorbing resin and another thermoplastic resin, or a mixed fiber of these fibers and a fiber made of a thermoplastic resin. Also good.

Polyester polymers, polyamide polymers, and polyolefin polymers are suitable as the thermoplastic resin used in the composite, blending or blending with the thermoplastic water-absorbing resin.
The water-absorbing nonwoven fabric is preferably manufactured by a spunbond method or a melt blow method.

  The water-absorbent nonwoven fabric composed of water-absorbing fibers using the thermoplastic water-absorbent resin of the present invention does not require post-processing for imparting water absorption, and is advantageous in terms of cost. It is possible to control the balance of strength and strength, and in thermoplastic nonwoven fabrics, it has high water absorption and water retention without greatly impairing strength, and is suitable for applications that require water absorption, moisture absorption and desorption Available to:

The water-absorbing long-fiber nonwoven fabric of the present invention is a water-absorbing nonwoven fabric composed of water-absorbing fibers containing a specific range of a thermoplastic water-absorbing resin copolymerized with polyalkylene glycol, and having excellent water absorption and water retention. Yes, the water absorption rate by the JIS-L-1096 dropping method is 55 seconds or less, and the water retention rate is 7% or more.
The thermoplastic water-absorbent resin used in the present invention is a thermoplastic water-absorbent resin having a moisture absorption rate of 7% or more and a water retention rate of 15% or more at 40 ° C. and a relative humidity of 80%, and is copolymerized with a polyalkylene glycol. It is a thermoplastic water-absorbing resin. A thermoplastic water absorbent resin having a moisture absorption rate of 9% or more and a water retention rate of 20% or more at 40 ° C. and a relative humidity of 80% is preferable.

  The thermoplastic water-absorbing resin is a resin composed of a copolymer of a polytetramethylene terephthalate main component polyester and polyethylene glycol, and the copolymerization amount of polyethylene glycol is 5 to 90% by weight, preferably 10%. It is in the range of -80% by weight, particularly preferably 30-60% by weight. The copolymerization amount ratio of polyethylene glycol in the thermoplastic water-absorbing resin is set in consideration of the balance between spinning stability and water absorption, and can be contained within a range not impairing the spinning stability.

  The content of the water absorbent resin in the water absorbent fibers is in the range of 1 to 100% by weight. As illustrated in FIG. 1, the strength of the nonwoven fabric and the water retention rate are in a contradictory relationship, but in view of balancing the characteristics of the two, the content of the water-absorbent resin is preferably 10 to 90% by weight. More preferably, it is 30 to 70% by weight, and when it is in this range, excellent water absorption and water retention can be obtained without greatly impairing the strength.

FIG. 1 illustrates the relationship between blend ratio, water retention, and strength when a water-absorbing resin is blended with a polyethylene terephthalate resin. As can be seen from this figure, when the water-absorbent resin is not added, the water retention rate is about 3%. However, when 10% is added, the water retention rate is about 3 times that of the case where no water addition is added. The water retention rate surprisingly increases to about 10 times 30% when% addition is made, and it can be seen that the water retention rate increases in proportion to the amount of water-absorbing resin added. Until now, there was no polyester non-woven fabric with such a large water retention rate.

  Inferring from such behavior, it is presumed that the water-absorbent resin contained in the water-absorbent fibers constituting the nonwoven fabric is uniformly dispersed in the single yarn. It can be said that when water is absorbed, the water-absorbing resin has a special structure that embeds moisture, retains it, and is difficult to release. It is presumed that the hydrophobic fiber structure has a structure that embeds moisture, and the polyethylene glycol copolymerization ratio is greatly involved in the structure. The water-absorbing nonwoven fabric of the present invention is a nonwoven fabric composed of water-absorbing fibers having such a special structure.

The melt viscosity of the thermoplastic water-absorbent resin of the present invention is not particularly limited, but in order to obtain fibers by a conventional spunbond method or melt blow method, from the viewpoint of productivity, melt at a shear rate of 1000 sec- ^1. It is preferable to use one having a viscosity in the range of 100 to 10,000 poise.
Although the fineness of the fiber used for the water-absorbing nonwoven fabric varies depending on the production method, a range of 0.01 to 25 dtex, particularly 0.05 to 15 dtex is appropriate. In particular, it is suitable for making a water-absorbing resin into ultrafine fibers using a melt blow method, and it is preferable to form a nonwoven fabric by this method, and a water-absorbing ultrafine fiber having a fineness of 0.5 to 5 μm in fiber diameter is obtained. It is desirable to be obtained.

Examples of the thermoplastic resin used for the composite with the thermoplastic water-absorbing resin, mixing, or mixing with the water-absorbing fiber include polyester polymers, polyamide polymers, and polyolefin polymers.
Examples of the polyolefin polymer include polypropylene, low density polyethylene, and high density polyethylene. As for polypropylene, it may be synthesized by a general Ziegler-Natta catalyst or may be synthesized by a single site active catalyst typified by metallocene. Examples of polyethylene include linear low density polyethylene, low density polyethylene, and high density polyethylene. Furthermore, it may be a copolymer of polypropylene and polyethylene or a polymer obtained by adding polyethylene or other additives into polypropylene.

Examples of the polyamide polymer include nylon 4, nylon 6, nylon 46, nylon 66, nylon 11, nylon 12, nylon MXD6 (polymetaxylene adipamide), and the like. Furthermore, these nylon-based copolymers or a mixture thereof may be used.
Examples of the polyester-based polymer include polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, and biodegradable polyester. Furthermore, a copolymer mainly composed of these polyesters or a mixture thereof may be used.

The melt viscosity of the thermoplastic resin is not particularly limited, but in order to obtain fibers by a conventional spunbond method or melt blow method, the melt viscosity at a shear rate of 1000 sec ⁻¹ is 100 from the viewpoint of productivity. It is preferable to use those in the range of 10000 poise.
Further, the thermoplastic water-absorbent fiber of the present invention includes other commonly used additive components, for example, impact modifiers such as various elastomers, crystal nucleating agents, and anti-coloring agents, as long as the object of the present invention is not impaired. , Antioxidants such as hindered phenols and hindered amines, mold release agents such as ethylenebisstearylamide and higher fatty acid esters, heat-resistant agents such as copper compounds typified by copper halides, epoxy compounds, plasticizers, lubricants, weathering agents Additives such as flame retardants and colorants can be added.

In the present invention, the water-absorbing fiber may be a mixture of a thermoplastic water-absorbing resin and a thermoplastic resin, and the cross-sectional shape of the fiber is also a circle or ellipse, a polygon such as a triangle or square, a flat or hollow, etc. This may be an irregular cross-sectional shape, and can be arbitrarily set according to required characteristics.
The water-absorbing nonwoven fabric of the present invention is obtained using a known method, and a conventionally known method can be arbitrarily employed as the production method, and there is no particular limitation.
Short fibers or long fibers are used as the fibers constituting the water-absorbing nonwoven fabric, and the formation method thereof includes a spinning method represented by a spunbond method and a melt blow method, a dry method such as carding and air laying, and a papermaking method. Any method such as a wet method may be used.

As a method of adhering webs made of hygroscopic fibers, thermal bonding methods such as calendar method and through air heating method, chemical bonding method using adhesive, needle punch method, hydroentanglement method, stitch bond method, etc. Any method such as a mechanical bonding method may be used.
The water-absorbing nonwoven fabric of the present invention obtained by the spunbond method or the melt blow method has high physical characteristics such as no short fiber falling off due to breakage of the bonding part, and has high productivity, compared with the card type short fiber nonwoven fabric. Since it has many advantages, it is used in a wide range of applications, mainly in hygiene, civil engineering, architecture, agriculture / horticulture, and food packaging materials, and is suitable as the water-absorbent nonwoven fabric of the present invention.

The water-absorbing nonwoven fabric of the present invention can be obtained by the following method, for example.
For fiber formation of the thermoplastic water-absorbing nonwoven fabric, melt spinning may be performed using a commonly used spinneret. The spun yarn is cooled and then stretched, and the web is collected on a conveyor to obtain a fabric by an arbitrary method. Furthermore, the water-absorbing nonwoven fabric of the present invention may be provided with other conventional post-processing, for example, a flame retardant, a deodorant, an antibacterial agent, an acaricide, etc., within a range not to impair the purpose of the present invention They may be dyed or water repellent.

In addition, the method of mixing the water-absorbent resin and the thermoplastic resin when forming the mixed fiber includes a method of masterbatching the resin to be mixed, a method of mixing by dry blending, etc. It is preferable to adopt.
Also, the shape, form, basis weight, etc. of the water-absorbing nonwoven fabric of the present invention can be arbitrarily set according to the required characteristics.
In addition, printing, dyeing, coating processing, etc. can be performed on the water-absorbing nonwoven fabric, and there is no problem even if different types of materials, manufacturing methods, and products are combined.

  The water-absorbing nonwoven fabric of the present invention can be widely used in applications where conventional water-absorbing materials are used. For example, apparel materials such as apparel materials, disposable apparel, and shoe materials, protective apparel such as protective clothing, protective equipment, medical uses such as surgical gowns, masks, haptic base fabrics, roofing, tufted carpet base fabrics, anti-condensation sheets Architectural applications such as, reinforcing materials, protective materials, civil engineering applications such as underground pipe repair materials, automotive interiors, vehicle applications such as automobile parts, sanitary applications such as emergency supplies, cleaning products, and hand towels, carpets, furniture components, Furniture and interior applications such as wallpaper, wipers such as wet wipers and cleaning materials, filter applications such as air filters, bag filters, electret filters, bedding applications such as futons, futon bags, pillow covers, solid sheets, grass protection Agricultural / horticultural applications such as seats, garden planters, artificial leather base fabrics, synthetic leather base fabrics, PVC leather base fabrics Of artificial leather such base fabric applications, storage supplies, packaging materials such as foods, living materials applications such as kitchen utensils, electrical material, or the like industrial materials applications such as product material, equipment member.

Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.
Measurement methods, evaluation methods, etc. are as follows.
<Water absorption speed>
The water absorption speed was evaluated by the number of seconds required for water absorption measured by the method shown in 6.26.1 dropping method of JIS-L-1096. It can be said that the smaller the number of seconds, the greater the water absorption speed.

<Water retention rate of nonwoven fabric>
The water retention of the nonwoven fabric was evaluated based on the water absorption represented by the following formula (1). First, the sample was conditioned at a temperature of 20 ° C. and a relative humidity of 65% for 24 hours to measure the weight W1 (g), then immersed in tap water at a temperature of 20 ° C. for 24 hours, taken out, and centrifuged. After dehydration at 3500 rpm for 5 minutes, the weight W2 (g) was measured, and the water retention rate T0 (%) was determined by the following formula (1).
Water retention rate T0 (%) = [(W2-W1) / W1] × 100 (1)

<Intrinsic viscosity of polyester>
Orthochlorophenol was used as a solvent, and measurement was performed by a conventional method under the conditions of a sample concentration of 1 g / 100c and a temperature of 35 ° C.
<Melt flow rate>
The melt flow rate (MFR) was measured according to the method described in JIS-K-7210.
<Relative viscosity of polyamide>
Measurement was carried out by a conventional method under the conditions of a sample concentration of 1 g / 100 cc and a temperature of 25 ° C. using sulfuric acid having a concentration of 97% as a solvent.

[ Reference Example 1]
Copolymer polyester resin of polytetramethylene terephthalate and polyethylene glycol having an intrinsic viscosity of 0.92 and a polyethylene glycol copolymerization rate of 45 wt% is supplied to a conventional spunbond melt spinning apparatus and melted uniformly at 230 ° C. Mixed, melt-spun from a spinneret having a spinning hole with a circular cross section, taken up at a take-up speed of 3000 m / min, collected on the moving web collecting surface, collected and deposited, and 20 μm water-absorbing long fibers A thermoplastic web made of 100% thermoplastic water-absorbing resin having a basis weight of 40 g / m ² was obtained.
The resulting web of thermoplastic water-absorbing fibers was partially thermocompression bonded at a linear pressure of 45 N / cm between a pinpoint embossed (crimp area ratio 7.1%) roll heated to 125 ° C. and a flat roll to 40 g / A non-woven fabric of m ² was prepared. Table 1 shows the physical properties of the obtained nonwoven fabric. Although the tensile strength is slightly low, the water absorption rate is extremely excellent at 0.9 seconds, and the water retention rate is 84.8%, which is very high.

[ Reference Example 2]
A thermoplastic web made of 100% thermoplastic water-absorbing resin was obtained under the same conditions as in Reference Example 1, and then the web made of the obtained water-absorbing fibers was nozzle diameter 0.15 mm, nozzle pitch 0.8 mm, row A columnar flow having a water pressure of 50 kg / cm ^{2 was} ejected from several rows of nozzles and subjected to hydroentanglement to prepare a 40 g / m ² nonwoven fabric. Table 1 shows the physical properties of the obtained nonwoven fabric. Although the tensile strength is slightly low, the water absorption rate is extremely excellent at 0.9 seconds, and the water retention rate is 84.8%, which is very high.

[ Reference Example 3]
A thermoplastic web composed of 100% thermoplastic water-absorbent resin was obtained under the same conditions as in Reference Example 1, and then the web composed of the obtained water-absorbent fibers was punched at a density of 10 pieces / cm ² as a needle punch condition. Then, a 40 g / m ² non-woven fabric was prepared by processing at a needle penetration depth of 10 mm. Table 1 shows the physical properties of the obtained nonwoven fabric. The water retention rate is 84.8%, and the water absorption speed is 0.9 seconds.

[ Reference Example 4]
Copolymer polyester resin of polytetramethylene terephthalate and polyethylene glycol having an intrinsic viscosity of 0.92 and a polyethylene glycol copolymerization rate of 45 wt% is supplied to a conventional melt blow melt spinning apparatus and melted and mixed uniformly at 270 ° C. The melt is spun from a spinneret having a spinning hole with a circular cross section, and is collected and deposited on a moving web collecting surface to obtain a web having a basis weight of 40 g / m ² made of 2.5 μm water-absorbing fibers. It was. The web made of the water-absorbing fibers was thermocompression bonded between a pair of flat rolls heated to 100 ° C. at a linear pressure of 45 N / cm to prepare a 40 g / m ² nonwoven fabric. Table 1 shows the physical properties of the obtained nonwoven fabric. Table 1 shows the physical properties of the obtained nonwoven fabric. The water retention rate is 84.8%, and the water absorption speed is 0.9 seconds, which are very high water absorption characteristics.
Looking at the results of Reference Example 1 to Reference Example 4, the water-absorbent nonwoven fabric made of 100% thermoplastic water-absorbent resin bonding method, also by changing the fiber fineness, it has the same absorption properties, this water It can be said that the characteristics reflect the water absorption characteristics of the thermoplastic water absorbent resin.

[ Reference Example 5]
A polypropylene resin having an MFR of 40 is dried so that the content of a copolymerized polyester resin of polytetramethylene terephthalate and polyethylene glycol having an intrinsic viscosity of 0.92 and a polyethylene glycol copolymerization rate of 45 wt% is 10 wt%. The mixture was blended and fed to a conventional spunbond melt spinning apparatus. Next, it is uniformly melt-mixed at 230 ° C., melt-spun from a spinneret having a spinning hole having a circular cross section, taken up at a speed of 3200 m / min, spread and dispersed, and collected on a moving web collecting surface. A web composed of 2.7 dtex fibers was deposited to be partially thermocompression bonded at a linear pressure of 45 N / cm between a pinpoint embossed (crimp area ratio 7.1%) roll heated to 135 ° C. and a flat roll. Thus, a 40 g / m ² nonwoven fabric was prepared. The physical properties of this nonwoven fabric are shown in Table 1.
The water-absorbing resin content is 10%, and compared with Comparative Example 1 described later, the water retention rate is about 5-fold increase from 1.8% to 8.7%, which is sufficient for polypropylene nonwoven fabric. Water absorption could be imparted.

[Example 6]
The core / sheath weight is made of a polypropylene resin having a MFR of 40 and a sheath component of a polytetramethylene terephthalate-polyethylene glycol copolymer polyester resin having an intrinsic viscosity of 0.92 and a polyethylene glycol copolymerization rate of 45 wt%. It is melt spun by a conventional method at a ratio of 70/30, taken up at a speed of 3200 m / min, collected and deposited on a moving web collecting surface that is spread and dispersed, and has a basis weight of 40 g of a 2.7 dtex water-absorbing fiber. A web of / m ² was obtained. The obtained water-absorbing fiber web was partially thermocompression bonded at a linear pressure of 45 N / cm between a pinpoint embossed (crimp area ratio 7.1%) roll heated to 125 ° C. and a flat roll, and 40 g / m ^2. A non-woven fabric was prepared. The physical properties of this nonwoven fabric are shown in Table 1.
The water-absorbing resin content is 30%. Compared to Comparative Example 1 described later, the water retention rate is about 15 times increased from 1.8% to 25.5%, and the water absorption rate is greatly increased. It was improved and sufficient water absorption was imparted to the polypropylene nonwoven fabric.

[Example 7]
While the MFR40 polypropylene resin was heated to 230 ° C. and melted, it was extruded from the first extruder, while the polytetramethylene terephthalate having an intrinsic viscosity of 0.92 and a polyethylene glycol copolymerization ratio of 45 wt% and polyethylene glycol The copolyester resin is extruded from the second extruder while being melted by heating to 230 ° C., introduced into a spinneret equipped with a side-by-side type composite fiber spinning hole by a gear pump, and both resins are melt-spun from the spinning hole, and the speed is 3200 m. Per minute, spread and dispersed, and collected and deposited on the moving web collection surface to obtain a web having a basis weight of 40 g / m ² made of side-by-side type composite fibers. The resulting web made of water-absorbent fibers was partially thermocompression bonded at a linear pressure of 45 N / cm between a pinpoint embossed (crimp area ratio 7.1%) roll heated to 130 ° C. and a flat roll,
A nonwoven fabric of 40 g / m ² was prepared. The physical properties of this nonwoven fabric are shown in Table 1.
The water-absorbing resin content is 50%, and compared with Comparative Example 1 to be described later, the water retention rate is about 25 times increased from 1.8% to 42.4%, and the water absorption rate is greatly increased. It was improved and sufficient water absorption was imparted to the polypropylene nonwoven fabric.

[ Reference Example 8 to Reference Example 10]
Polypropylene resin having an MFR of 900 having an intrinsic viscosity of 0.92 and a polyethylene glycol copolymerization ratio of 45 wt%. The content of the copolymer polyester resin of polytetramethylene terephthalate and polyethylene glycol is (30, 50, 70) wt. % Was mixed by dry blending and supplied to a conventional melt blow melt spinning apparatus. Next, a web composed of 2.5 μm fibers is melt-mixed uniformly at 270 ° C., melt-spun from a spinneret having a spinning hole with a circular cross section, and collected and deposited on a moving web collecting surface. A 40 g / m ² non-woven fabric was formed by thermocompression bonding between a pair of flat rolls formed and heated to 100 ° C. at a linear pressure of 45 N / cm. Table 1 shows the physical properties of the nonwoven fabric with the mixing ratio of the water-absorbing resin as 30% ( Reference Example 8), 50% ( Reference Example 9), and 70% ( Reference Example 10). Although the water absorption rate was slightly low, good results were obtained with excellent water retention.

[ Reference Example 11]
The content of the copolymerized polyester resin of polytetramethylene terephthalate and polyethylene glycol in which the relative viscosity is 2.5 and the intrinsic viscosity is 0.92 and the copolymerization ratio of polyethylene glycol is 45 wt%. The mixture was mixed by dry blending so as to be 10 wt%, and supplied to a conventional spunbond melt spinning apparatus. Next, the mixture is uniformly melt-mixed at 260 ° C., melt-spun from a spinneret having a spinning hole with a circular cross section, taken at a speed of 4250 m / min, spread and dispersed, and collected on a moving web collecting surface. A web having a basis weight of 40 g / m ² made of nylon 6 fibers of 2.0 dtex was deposited. The obtained water-absorbing fiber web was partially thermocompression bonded at a linear pressure of 45 N / cm between a pinpoint embossed (crimp area area 7.1%) roll heated to 180 ° C. and a flat roll to a weight of 40 g / m ² . A non-woven fabric was created. Table 1 shows the physical properties of the obtained nonwoven fabric.
The water-absorbing resin content is 10%, and compared with Comparative Example 3 described later, the water retention rate is about 1.5 times increased from 12.3% to 19.6%, and the water absorption rate is also It was greatly improved and sufficient water absorption was imparted to the nylon nonwoven fabric.

[Example 12]
Nylon 6 resin (N6) having a relative viscosity of 2.6 as a core, a polytetramethylene terephthalate-polyethylene glycol copolymer polyester resin having an intrinsic viscosity of 0.92 and a polyethylene glycol copolymerization rate of 45 wt% as a sheath component The core / sheath weight ratio is 70/30, melt-spun by a conventional method, taken up at a speed of 4250 m / min, spread and dispersed, and collected and deposited on the moving web collecting surface to obtain 2.0 dtex. A web made of water-absorbing fibers having a basis weight of 40 g / m ² was obtained. The obtained water-absorbing fiber web was partially thermocompression bonded at a linear pressure of 45 N / cm between a pinpoint embossed (crimp area ratio 7.1%) roll heated to 130 ° C. and a flat roll, and 40 g / m ^2. A non-woven fabric was prepared. The physical properties of this nonwoven fabric are shown in Table 1.
The water-absorbing resin content is 30%. Compared to Comparative Example 3 to be described later, the water retention rate is increased approximately 3 times from 12.3% to 34.1%, and the water absorption rate is greatly increased. It was improved and sufficient water absorption was imparted to the nylon nonwoven fabric.

[Example 13]
Nylon 6 resin (N6) having a relative viscosity of 2.6 is extruded from the first extruder while being melted by heating to 260 ° C., while the intrinsic viscosity is 0.92 and the copolymerization ratio of polyethylene glycol is 45 wt%. A copolymer polyester resin of polytetramethylene terephthalate and polyethylene glycol is extruded from the second extruder while being melted by heating to 230 ° C., introduced into a spinneret equipped with a side-by-side type composite fiber spinning hole by a gear pump, and from the spinning hole. Both resins are melt-spun, taken up at a speed of 4250 m / min, spread and dispersed, collected and deposited on a moving web collecting surface to obtain a web having a basis weight of 40 g / m ² made of side-by-side composite fibers. It was. The obtained water-absorbing fiber web was partially thermocompression bonded at a linear pressure of 45 N / cm between a pinpoint embossed (crimp area area ratio 7.1%) roll heated to 150 ° C. and a flat roll to obtain 40 g / m ^2. A non-woven fabric was prepared. The physical properties of this nonwoven fabric are shown in Table 1.
The water-absorbing resin content is 50%, and compared with Comparative Example 3 described later, the water retention rate is increased approximately 4 times from 12.3% to 48.6%, and the water absorption rate is also greatly increased. It was improved and sufficient water absorption was imparted to the nylon nonwoven fabric.

[ Reference Examples 14 to 16]
The content of the copolymerized polyester resin of polytetramethylene terephthalate and polyethylene glycol having an intrinsic viscosity of 0.92 and a copolymerization ratio of polyethylene glycol of 45 wt% in nylon 6 resin (N6) having a relative viscosity of 1.5 They were mixed by dry blending so as to be 30 wt% ( Reference Example 14), 50 wt% ( Reference Example 15), and 70 wt% ( Reference Example 16), and supplied to a conventional melt blow melt spinning apparatus. Next, a web made of 2.5 μm fibers is melt-mixed uniformly at 290 ° C., melt-spun from a spinneret having a spinning hole having a circular cross section, and collected and deposited on a moving web collecting surface. A 40 g / m ² non-woven fabric was formed by thermocompression bonding between a pair of flat rolls formed and heated to 100 ° C. at a linear pressure of 45 N / cm. The physical properties of this nonwoven fabric are shown in Table 1.
In contrast to Comparative Example 4 described later, the intensity is almost equal, excellent water absorption, water retention ratio, in contrast to Comparative Example 4, about 3-fold in Reference Example 14, from about 4 in Reference Example 15 Double, Reference Example 16
The increase effect of about 5 times was obtained.

[Examples 17 to 19]
Polyethylene terephthalate resin (PET) having an intrinsic viscosity of 0.77 has a content of a copolymerized polyester resin of polytetramethylene terephthalate and polyethylene glycol having an intrinsic viscosity of 0.92 and a copolymerization ratio of polyethylene glycol of 45 wt%. They were mixed by dry blending so as to be 30 wt% (Example 17), 50 wt% (Example 18), and 70 wt% (Example 19), and supplied to a conventional spunbond melt spinning apparatus. Next, uniformly melted and mixed at 290 ° C., melt spun from a spinneret having a spinning hole having a circular cross section, taken up at a speed of 4500 m / min, spread and dispersed, and collected on a moving web collecting surface. Then, a web made of 2.0 dtex fibers was deposited to be partially thermocompression bonded at a linear pressure of 45 N / cm between a pinpoint embossing (crimping area ratio 7.1%) roll heated to 220 ° C. and a flat roll. Thus, a 40 g / m ² nonwoven fabric was prepared. The physical properties of this nonwoven fabric are shown in Table 1.
The water-absorbing resin content is 30%, 50%, and 70%. When compared with Comparative Example 5 described later, the water retention rate is 25.5% and 42.4 compared to 3.4% of Comparative Example 5. %, 60.5%, which has an effect of about 8 times to about 18 times, the water absorption speed is greatly improved, and sufficient water absorption can be imparted to the polyester nonwoven fabric. .

[Example 20]
Polyethylene terephthalate resin (PET) having an intrinsic viscosity of 0.77 as the core, Polytetramethylene terephthalate and polyethylene glycol copolymer polyester resin having an intrinsic viscosity of 0.92 and a polyethylene glycol copolymerization rate of 45 wt% as a sheath component The core / sheath weight ratio is 70/30, melt spinning by a conventional method, taken up at a speed of 4250 m / min, collected and deposited on the moving web collecting surface that is dispersed and moved, and dipped in 2.0 dtex. A web of 40 g / m ^{2 in} weight per unit area was obtained. The obtained water-absorbing fiber web was partially thermocompression bonded at a linear pressure of 45 N / cm between a pinpoint embossed (crimp area ratio 7.1%) roll heated to 130 ° C. and a flat roll, and 40 g / m ^2. A non-woven fabric was prepared. The physical properties of this nonwoven fabric are shown in Table 1.

[Example 21]
A polyethylene terephthalate resin (PET) having an intrinsic viscosity of 0.77 is extruded from the first extruder while being melted by heating to 290 ° C., while the intrinsic viscosity is 0.92 and the copolymerization ratio of polyethylene glycol is 45 wt%. A copolymer polyester resin of polytetramethylene terephthalate and polyethylene glycol is extruded from the second extruder while being melted by heating to 230 ° C., introduced into a spinneret equipped with a side-by-side type composite fiber spinning hole by a gear pump, and from the spinning hole. Both resins were melt-spun, taken up at a speed of 4250 m / min, collected and deposited on a moving web collecting surface that was spread and dispersed to obtain a web having a basis weight of 40 g / m ² made of side-by-side type composite fibers. . The obtained water-absorbing fiber web was partially thermocompression bonded at a linear pressure of 45 N / cm between a pinpoint embossed (crimp area ratio 7.1%) roll heated to 210 ° C. and a flat roll, and 40 g / m ^2. A non-woven fabric was prepared. The physical properties of this nonwoven fabric are shown in Table 1.

[ Reference Example 22]
Polyethylene terephthalate resin (PET) having an intrinsic viscosity of 0.42 has a content of a copolymerized polyester resin of polytetramethylene terephthalate and polyethylene glycol having an intrinsic viscosity of 0.92 and a copolymerization ratio of polyethylene glycol of 45 wt%. The mixture was mixed by dry blending so as to be 30 wt% and supplied to a conventional melt blow melt spinning apparatus. Next, a web made of 2.5 μm fibers is melt-mixed uniformly at 290 ° C., melt-spun from a spinneret having a spinning hole having a circular cross section, and collected and deposited on a moving web collecting surface. A 40 g / m ² non-woven fabric was formed by thermocompression bonding between a pair of flat rolls formed and heated to 100 ° C. at a linear pressure of 45 N / cm. The physical properties of this nonwoven fabric are shown in Table 1.

[ Reference Example 23]
Polyethylene terephthalate resin (PET) having an intrinsic viscosity of 0.42 has a content of a copolymerized polyester resin of polytetramethylene terephthalate and polyethylene glycol having an intrinsic viscosity of 0.92 and a copolymerization ratio of polyethylene glycol of 45 wt%. The mixture was mixed by dry blending so as to be 50 wt%, and supplied to a conventional melt blow melt spinning apparatus. Next, a web made of 2.5 μm fibers is melt-mixed uniformly at 290 ° C., melt-spun from a spinneret having a spinning hole having a circular cross section, and collected and deposited on a moving web collecting surface. A 40 g / m ² non-woven fabric was formed by thermocompression bonding between a pair of flat rolls formed and heated to 100 ° C. at a linear pressure of 45 N / cm. The physical properties of this nonwoven fabric are shown in Table 1.

[ Reference Example 24]
Polyethylene terephthalate resin (PET) having an intrinsic viscosity of 0.42 has a content of a copolymerized polyester resin of polytetramethylene terephthalate and polyethylene glycol having an intrinsic viscosity of 0.92 and a copolymerization ratio of polyethylene glycol of 45 wt%. The mixture was mixed by dry blending so as to be 70 wt%, and supplied to a conventional melt blow melt spinning apparatus. Next, a web made of 2.5 μm fibers is melt-mixed uniformly at 290 ° C., melt-spun from a spinneret having a spinning hole having a circular cross section, and collected and deposited on a moving web collecting surface. A 40 g / m ² non-woven fabric was formed by thermocompression bonding between a pair of flat rolls formed and heated to 100 ° C. at a linear pressure of 45 N / cm. The physical properties of this nonwoven fabric are shown in Table 1.

[Comparative Example 1]
MFR40 polypropylene resin (PP) is supplied to a conventional spunbond melt spinning apparatus, melted and mixed uniformly at 230 ° C., melt-spun from a spinneret having a spinning hole with a circular cross section, and taken up at a take-up speed of 3000 m / min. The web was spread and dispersed and collected and deposited on the moving web collecting surface to obtain a web having a basis weight of 40 g / m ² made of 20 μm polypropylene fibers. Nonwoven fabric of 40 g / m ² by partial thermocompression bonding between a pinpoint embossing (crimping area ratio 7.1%) roll heated to 135 ° C. and a flat roll at a linear pressure of 45 N / cm. It was created. Table 2 shows the physical properties of the obtained nonwoven fabric.

[Comparative Example 2]
MFR900 polypropylene resin (PP) is supplied to a conventional melt blow melt spinning apparatus, uniformly melted and mixed at 270 ° C., melt spun from a spinneret having a spinning hole with a circular cross section, and on the moving web collecting surface The web was collected and deposited to obtain a web having a basis weight of 40 g / m ² made of 2.5 μm polypropylene fibers. The web made of polypropylene fibers was thermocompression bonded between a pair of flat rolls heated to 100 ° C. at a linear pressure of 45 N / cm to prepare a 40 g / m ² nonwoven fabric. Table 2 shows the physical properties of the obtained nonwoven fabric.

[Comparative Example 3]
Nylon 6 resin (N6) having a relative viscosity of 2.6 is supplied to a conventional spunbond melt spinning apparatus, melted and mixed uniformly at 260 ° C., melt-spun from a spinneret having a spinning hole having a circular cross section, and taken up. The web was taken up at a speed of 4250 m / min, collected on the moving web collecting surface that was dispersed and moved, and deposited to obtain a web composed of 20 μm nylon 6 fibers with a basis weight of 40 g / m ² . The obtained nylon 6 fiber web was partially thermocompression bonded at a linear pressure of 45 N / cm between a pinpoint embossed (crimp area ratio 7.1%) roll heated to 185 ° C. and a flat roll to a weight of 40 g / m ² . A non-woven fabric was created. Table 2 shows the physical properties of the obtained nonwoven fabric.

[Comparative Example 4]
Nylon 6 resin (N6) having a relative viscosity of 1.6 is supplied to a conventional melt blow melt spinning apparatus, melted and mixed uniformly at 290 ° C., melt-spun from a spinneret having a spinning hole having a circular cross section, and moved. A web having a basis weight of 40 g / m ² made of 2.5 μm nylon 6 fibers was obtained by collecting and depositing on the web collecting surface. The web of nylon 6 fibers obtained was thermocompression bonded between a pair of flat rolls heated to 110 ° C. at a linear pressure of 45 N / cm to produce a 40 g / m ² non-woven fabric. Table 2 shows the physical properties of the obtained nonwoven fabric.

[Comparative Example 5]
Polyethylene terephthalate resin (PET) having an intrinsic viscosity of 0.70 is supplied to a conventional spunbond melt spinning apparatus, melted and mixed uniformly at 290 ° C., melt-spun from a spinneret having a spinning hole having a circular cross section, and taken up. The web was taken up at a speed of 4250 m / min, spread and dispersed, and collected and deposited on the moving web collection surface to obtain a web having a basis weight of 40 g / m ² made of 14 μm PET fibers. 40 g / m ² non-woven fabric obtained by partial thermocompression bonding between a pinpoint embossed (crimping area ratio 7.1%) roll heated to 235 ° C. and a flat roll at a linear pressure of 45 N / cm. It was created. Table 2 shows the physical properties of the obtained nonwoven fabric.

[Comparative Example 6]
Polyethylene terephthalate resin (PET) having an intrinsic viscosity of 0.42 is supplied to a conventional melt blow melt spinning apparatus, melted and mixed uniformly at 300 ° C., melt spun from a spinneret having a spinning hole having a circular cross section, and moved. The web having a basis weight of 40 g / m ² made of 2.5 μm PET fiber was obtained by collecting and depositing on the web collecting surface. The obtained web of PET fibers was thermocompression bonded at a linear pressure of 45 N / cm between a pair of flat rolls heated to 120 ° C. to produce a 40 g / m ² nonwoven fabric. Table 2 shows the physical properties of the obtained nonwoven fabric.
[Comparative Examples 7 and 8]
Table 2 shows properties of the water-absorbing nonwoven fabric made of 100% regenerated cellulose as Comparative Example 7 and 100% cotton as Comparative Example 8.

  The water-absorbent nonwoven fabric of the present invention has high physical properties such as no short fibers falling off due to breakage of the bonding portion, and high productivity, and has many advantages compared to card-type short fiber nonwoven fabrics. It is used in a wide range of applications, mainly in architecture, agriculture / horticulture, and food packaging materials, and is suitable as a long-fiber nonwoven fabric comprising the water-absorbing fibers of the present invention.

It is a related figure of the strength and water retention of the nonwoven fabric comprised with the blend fiber of PET resin and a water absorbing resin.

Claims (4)

Polyalkylene glycol be water-absorbent nonwoven fabric that consists of absorbent fibers containing a copolymerized thermoplastic water-absorbent resin in the range of 30 to 70 wt%, thermoplastic water-absorbing resin is polytetramethylene terephthalate A copolymer of polyester and polyethylene glycol as a main component, wherein the copolymerization amount of polyethylene glycol is 5 to 90% by weight, and the water-absorbing fiber is composed of a thermoplastic water-absorbing resin and a thermoplastic resin. A water-absorbing nonwoven fabric obtained by combining or blending , wherein the water- absorbing nonwoven fabric is a nonwoven fabric formed by a spunbond method.   The water-absorbing nonwoven fabric according to claim 1, wherein the water-absorbing nonwoven fabric has a water absorption rate of 55 seconds or less by a JIS-L-1096 dropping method and a water retention rate of 7% or more. The water-absorbent nonwoven fabric according to claim 1 or 2 , wherein the thermoplastic resin is a polyolefin resin, a polyamide resin, or a polyester resin. The water-absorbing nonwoven fabric according to any one of claims 1 to 3 , wherein the joining in the water-absorbing nonwoven fabric is a partial thermocompression bonding method, a water jet method, or a needle punch method.

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