JP2000192362A - Moisture-absorbing or releasing staple fiber non-woven fabric - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a moisture-absorbing or releasing staple fiber non-woven fabric, excellent in a moisture-absorbing or releasing property, having large strength, good dimensional stability and rich flexibility, not discoloring, even when used for a long period, excellent in weather resistance, and suitable as a raw material for, for example, disposable sanitary materials, general living- related materials, or partial industrial materials. SOLUTION: This non-woven fabric comprises sheath-core type conjugate structure staple fibers comprising a polyamide or a polyester as the sheath component and a polyalkylene oxide modified product singly or a mixture of the polyalkylene oxide modified product with a polyamide or polyester as the core component, and is partially heated and pressure-fused or subjected to an inter-fiber three-dimensional interlacing treatment to retain a prescribed shape. The polyalkylene oxide modified product is prepared by reacting a polyalkylene oxide and a polyol with a symmetrical aliphatic isocyanate compound.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is excellent in moisture absorption / desorption and weather resistance, high in strength, and high in flexibility. The present invention relates to a moisture-absorptive short-fiber nonwoven fabric suitable for a material.

[0002]

2. Description of the Related Art Nonwoven fabrics made of general-purpose thermoplastic polymers such as polyamides and polyesters have been known as materials for sanitary materials, general life related materials, or industrial materials. It is poor in moisture. On the other hand, as a nonwoven fabric having moisture absorption and desorption properties, a so-called spunlace nonwoven fabric in which natural fibers such as cotton and hemp are entangled and integrated is known, but this nonwoven fabric has low mechanical properties, particularly low strength, Since the material itself is not thermoplastic, the processing method is limited when forming a nonwoven fabric. The present inventors have attempted to solve such a problem.
JP-A-8-209450, JP-A-8-31719 and JP-A-9-217230 disclose a thermoplastic water-absorbing polymer comprising a sheath component comprising polyamide or polyester and a core component comprising a crosslinked product of polyethylene oxide and polyamide. Alternatively, a core-sheath composite fiber made of a mixture with polyester has been proposed. U.S. Pat. No. 4,767,825 proposes a nonwoven fabric composed of a water-absorbing polymer comprising a polyoxymethylene soft segment and a hard segment. However, although these core-in-sheath type composite fibers and nonwoven fabrics are excellent in moisture absorption / release properties, raw yarn performance or yarn forming properties, they have a problem that yellowing occurs when used for a long period of time, resulting in poor weather resistance. .

[0003]

DISCLOSURE OF THE INVENTION The present invention is intended to solve the above-mentioned problems, and is excellent in moisture absorption / release properties, high in strength, flexible, and has no discoloration even after long-term use. An object of the present invention is to provide a moisture-absorbing and desorbing short-fiber nonwoven fabric which has excellent weather resistance and is suitable for a material such as a disposable sanitary material, a general living-related material, or some industrial materials.

[0004]

SUMMARY OF THE INVENTION The present invention is to solve the above-mentioned problem, and has the following constitution as its gist. The sheath component is a polyamide or polyester, and the core component has a core-sheath composite structure composed of a polyalkylene oxide modified product obtained by reacting a polyalkylene oxide and a polyol with a symmetric aliphatic isocyanate compound, and The moisture-absorbing and desorbing short fiber, wherein the modified polyalkylene oxide is composed of short fiber in an amount of 5 to 30% by weight based on the weight of the fiber, and maintains a predetermined shape by partial heat welding. Non-woven fabric. A sheath-sheath type in which a sheath component is a polyamide or polyester, and a core component is a polyalkylene oxide-modified product obtained by reacting a polyalkylene oxide and a polyol with a symmetric aliphatic isocyanate compound, and a mixture of a polyamide or polyester. 5 to 30% by weight based on the fiber weight, having a composite structure and modified polyalkylene oxide as a core component
A short-fiber nonwoven fabric capable of absorbing and desorbing moisture, characterized in that the nonwoven fabric is composed of short fibers having a predetermined shape by partial thermal pressure welding. The sheath component is a polyamide or polyester, and the core component has a core-sheath composite structure composed of a polyalkylene oxide modified product obtained by reacting a polyalkylene oxide and a polyol with a symmetric aliphatic isocyanate compound, and The modified polyalkylene oxide component is composed of short fibers in an amount of 5 to 30% by weight based on the weight of the fibers, and retains a predetermined shape by three-dimensional entanglement between the fibers. Wet short fiber non-woven fabric. A sheath-sheath type in which a sheath component is a polyamide or polyester, and a core component is a polyalkylene oxide-modified product obtained by reacting a polyalkylene oxide and a polyol with a symmetric aliphatic isocyanate compound, and a mixture of a polyamide or polyester. 5 to 30% by weight based on the fiber weight, having a composite structure and modified polyalkylene oxide as a core component
A non-woven fabric having moisture-absorbing and desorbing properties, characterized in that the non-woven fabric has a predetermined shape by three-dimensional entanglement between the fibers.

[0005]

Next, the present invention will be described in detail. In the present invention, nylon 4, nylon 6, nylon 46, nylon 66, nylon 11, nylon 12, nylon MX are used as the polyamide used as the sheath component or the sheath component and a part of the core component of the short fiber constituting the nonwoven fabric.
Examples thereof include amide polymers such as D6 (polymetaxylene adipamide) and polybiscyclohexylmethanedecanamide, copolymers mainly containing these, and mixtures thereof. Examples of the polyester include an aromatic dicarboxylic acid such as terephthalic acid, isophthalic acid, and naphthalene-2,6-dicarboxylic acid, an aliphatic dicarboxylic acid such as adipic acid and sebacic acid, and esters thereof, and ethylene glycol. And an ester-based polymer having a diol compound such as diethylene glycol, 1,4-butanediol, neopentyl glycol, cyclohexane-1,4-dimethanol as an ester component, or a copolymer thereof. In addition, paraoxybenzoic acid, 5-sodium sulfoisophthalic acid, polyalkylene glycol, pentaerythritol, bisphenol A, and the like may be added or copolymerized to these ester polymers.

In the present invention, the modified polyalkylene oxide used as the core component of the short fibers constituting the nonwoven fabric is obtained by reacting a polyalkylene oxide and a polyol with a symmetric aliphatic isocyanate compound. By reacting a polyalkylene oxide and a polyol with a symmetric aliphatic isocyanate compound, an imide ring formed by a resonance structure between an isocyanate group and an aromatic ring as seen when an aromatic isocyanate compound is used is formed. Yellowing caused by the yellowing is suppressed, and the fibers do not yellow even after long-term use, and a nonwoven fabric having excellent weather resistance can be obtained.

The polyalkylene oxide-modified product is obtained by reacting a polyalkylene oxide and a polyol with a symmetric aliphatic isocyanate compound as described above. As the polyalkylene oxide, those having a weight average molecular weight of 500,000 to 500,000 can be suitably used. When the weight average molecular weight is less than 500,
If the water absorption of the resulting modified polyalkylene oxide is extremely lowered, or the melt viscosity becomes extremely high, the spinnability deteriorates, while if the weight average molecular weight exceeds 500,000, the resulting polyalkylene The oxide-modified product is eluted from the nonwoven fabric as a gel when absorbing water, and neither is preferable. Examples of the polyalkylene oxide having such a weight average molecular weight include polyethylene oxide, polypropylene oxide, ethylene oxide / propylene oxide copolymer, polybutylene oxide, and a mixture thereof. Polyethylene oxide, polypropylene oxide and ethylene oxide / propylene oxide copolymer can be suitably used.

[0008] The polyol is an organic compound having two hydroxyl groups (-OH) in the same molecule, for example, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, trimethylene. Glycol, 1,3-butanediol, 2,3-butanediol, 1,4-butanediol, 1,5-pentadiol, hexylene glycol, octylene glycol,
Glyceryl monoacetate, glyceryl monobutyrate, 1,6-hexanediol, 1,9-nonanediol, bisphenol A, etc., especially ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexane Diols and 1,9-nonanediol can be suitably used.

The above-mentioned symmetric aliphatic isocyanate compound to be reacted with the polyalkylene oxide and the polyol is an aliphatic isocyanate compound in which two isocyanate groups are present at symmetric positions in a molecule, for example, dicyclohexylmethane-4 4,4'-diisocyanate or 1,6-hexamethylene diisocyanate can be suitably used.

The modified polyalkylene oxide preferably has a melt viscosity of 1,000 to 20,000 poise at a temperature of 170 ° C. and an applied load of 50 kg / cm ² . If the melt viscosity is less than 1000 poise, the gel will elute on the fiber surface when absorbing water.On the other hand, if the melt viscosity exceeds 20,000 poise, the dispersibility with the polyamide or polyester will be reduced, and the spinnability will be deteriorated. Are not preferred.

In the non-woven fabric of the present invention, it is necessary that the short fiber constituting the non-woven fabric has a modified polyalkylene oxide as a core component in an amount of 5 to 30% by weight based on the weight of the fiber. When the weight ratio is less than 5%, the moisture absorption and desorption properties of the short fibers and thus the nonwoven fabric decrease. On the other hand, when the weight ratio exceeds 30%, the moisture absorption and desorption properties are excellent, but the strength of the short fibers and therefore the strength of the nonwoven fabric is increased. , And both are not preferred.
In the present invention, the composite ratio of the sheath component and the core component in the short fiber (sheath-core composite ratio) is calculated as follows: when the core component is only a polyalkylene oxide-modified product, the sheath component / core component (weight ratio) = 95.
/ 5 to 70/30. When the sheath component is a mixture of a polyalkylene oxide-modified product and a polyamide or polyester, the sheath component is not particularly limited. Component (weight ratio) = 60/40 to 40/6
It is preferably 0. When the composite ratio of the core component is larger than the above range, the moisture absorption and desorption properties of the short fibers are improved, but the spinning properties are deteriorated. On the other hand, if the composite ratio of the core component is smaller than the above range, the sheath component becomes thicker,
In addition, polyamide or polyester is excessively dispersed in the polyalkylene oxide-modified product of the core component, and the moisture absorption / release properties of short fibers are reduced.

In the nonwoven fabric of the present invention, it is necessary that the short fibers have a substantially core-in-sheath composite structure, and the core component imparts moisture absorption and desorption properties to the short fibers. In addition, the sheath component improves the spinnability and strength of the short fibers, and thus the strength of the nonwoven fabric. This short fiber may have a multi-core / sheath structure in addition to the normal core / sheath structure. The cross-sectional shape of the entire short fiber is not particularly limited as long as it is substantially a core-in-sheath cross section. In addition to a normal circular cross section, a general fiber such as a multilobal cross section, a flat cross section, or various irregular cross sections is used. The cross section adopted in the above may be used. These polymers may be melt-mixed in advance to form a master chip, or may be dry-blended.

In the nonwoven fabric of the present invention, if necessary, sodium polyacrylate and / or polyacrylic acid may be added to the core component of the core-sheath composite staple fiber, as long as the effects of the present invention are not impaired. -N-vinylpyrrolidone, poly (meth)
Acrylic acid or a copolymer thereof, or a water-absorbing polymer such as polyvinyl alcohol may be added together.

In addition, the core component and / or the sheath component of the core-sheath type composite staple fiber are not impaired as long as the effects of the present invention are not impaired.
If necessary, various additives such as a matting agent, a colorant, a flame retardant, a deodorant, a light stabilizer, a heat stabilizer, and an antioxidant may be added. In particular, when a benzotriazole-based ultraviolet absorber is contained in the sheath component and a phenolic antioxidant is contained in the core component, heat resistance and light resistance are improved, which is preferable. In addition, as a benzotriazole type ultraviolet absorber, 2- (2-hydroxy-3,5-di-t-amylphenyl) benzotriazole ("Seesorb 704" manufactured by Cypro Kasei Co., Ltd.), and as a phenolic antioxidant,
2-t-pentyl-6- (3,5-di-t-pentyl-
2-Hydroxybenzyl) -4-t-pentylphenyl acrylate ("Sumilyzer GS" manufactured by Sumitomo Chemical Co., Ltd.) can be suitably used.

The nonwoven fabric of the present invention retains its shape as a nonwoven fabric due to the thermal pressure welding between the constituent fibers in the partial thermal pressure welding region. This partial heat-pressing is, for example, formed by a heated embossing roll and a metal roll having a smooth surface, and the fibers in a portion of the embossing roll that abuts on the embossed pattern portion are fused to each other. This forms a point-like fused region. By this partial heat welding, the nonwoven fabric is provided with mechanical properties such as shape retention, dimensional stability and strength.

Further, the nonwoven fabric of the present invention retains its shape as a nonwoven fabric by three-dimensional entanglement of constituent fibers. The three-dimensional confounding of the constituent fibers is
For example, it is formed by injecting a high-pressure liquid flow onto a web. By this three-dimensional confounding,
The nonwoven fabric has shape retention and practically sufficient strength and flexibility.

The nonwoven fabric of the present invention can be efficiently produced by the following method. First, the polyamide or polyester constituting the sheath component of the short fiber, and the polymer constituting the core component, that is, the modified polyalkylene oxide or a mixture of the modified product and the polyamide or polyester are individually melted, and then mixed with a known composite. After spinning from a mold spinneret, the melt spun yarn is cooled by a known cooling device, and after applying a spinning oil agent, the yarn is taken up by a take-up roller to form an undrawn yarn, and once taken up or without being taken up Continuous drawing is performed, and the obtained drawn yarn is mechanically crimped using a crimping means such as a stuffing box, and then cut into a predetermined length to obtain short fibers. Stretching is performed by using a one-stage or plural-stage stretching machine and performing cold stretching or hot stretching. The stretching ratio and the stretching temperature when the undrawn yarn is stretched may be appropriately selected depending on the kind of the polymer to be used and the amount of the polyalkylene oxide-modified product to be used as the core component. For mechanical crimping, set the number of crimps to 8 to 3
5/25 mm, preferably 10-30 / 25 mm. When the number of crimps is less than 8 pieces / 25 mm,
In the next carding step, an unspread portion is apt to occur, while, when the number of crimps exceeds 35/25 mm, nep tends to occur, which is not preferable. The degree of crimp is preferably 5.0% or more. Crimp degree is 5.0
%, It is not preferable because in the next carding step, the conjugation property of the fiber is deteriorated and the density unevenness is liable to occur on the web.

Next, the short fibers are carded using a carding machine or the like to produce a card web, and the resulting card web is subjected to a partial heat-pressing treatment to heat-contact the constituent fibers with each other. The short fiber nonwoven fabric of the present invention is obtained by subjecting the constituent fibers to three-dimensional entanglement by performing a liquid flow treatment. In producing the card web, the fiber direction of the web was such that the constituent fibers were arranged in the machine direction of the card machine in a parallel fiber web, the constituent fibers were randomly arranged in a random fiber web, or the constituent fibers were arranged in the middle of the two. Any of a semi-random fiber web may be used. The raw cotton used in the production of the web, that is, the constituent fibers of the nonwoven fabric of the present invention, may contain at least a certain amount of the above-mentioned short fibers, and therefore, the above-mentioned short fibers may be used alone, or May be mixed with other fibers.

In the short-fiber nonwoven fabric of the present invention, when performing the partial heat-pressing treatment, for example, a heated embossing roll and a metal roll having a smooth surface are used, and a portion of the embossing roll in contact with the embossing pattern portion is used. The fibers are fused together to form a point fusion zone. This partial thermocompression bonding has a specific area of the surface area of the web, but each pressed region need not necessarily be circular in shape, has an area of 0.1 to 1.0 mm ^2, The disposition density, that is, the pressure contact density is ^{2 to} 80 points / cm ² , preferably 4 to 60 points / cm ² . If the pressure contact density is less than 2 points / cm ² , mechanical properties such as shape retention and strength or dimensional stability of the non-woven fabric obtained by the heat pressure treatment are not improved. If the ratio exceeds the point / cm ² , the flexibility and the bulkiness of the nonwoven fabric decrease, and both are not preferred. Also,
The ratio of the area of the entire heat-welded region to the total surface area of the web, that is, the contact area ratio, is preferably 2 to 30%.
Preferably it is 4 to 20%. If the pressure contact area ratio is less than 2%, the nonwoven fabric obtained by the heat pressure treatment does not improve the mechanical properties such as shape retention and strength or dimensional stability, while the pressure contact area ratio exceeds 30%. In this case, the flexibility and bulkiness of the nonwoven fabric are reduced, and both are not preferred.

In the short-fiber nonwoven fabric of the present invention, a known method can be employed for subjecting the constituent fibers to three-dimensional entanglement by performing a high-pressure liquid flow treatment.
For example, the hole diameter is 0.05 to 1.0 mm, especially 0.1 to
There is a method in which a high-pressure liquid fluid having an injection pressure of 40 to 100 kg / m ² G is injected from the injection holes using an apparatus having a large number of 0.4 mm injection holes. The arrangement of the injection holes is arranged in a row in a direction orthogonal to the traveling direction of the web. This processing may be performed on either one side or both sides of the web, especially in the case of single-sided processing, the processing is performed by arranging the injection holes in a plurality of rows and lowering the injection pressure in the previous stage and increasing it in the later stage. A nonwoven fabric having a uniform and dense entangled form and a uniform formation can be obtained. As the high-pressure liquid, water at normal temperature or warm water is generally used. The distance between the injection hole and the web is preferably 1 to 15 cm. This distance is 1
If it is less than 15 cm, the formation of the web is disturbed. On the other hand, if this distance greatly exceeds 15 cm, the impact force when the liquid flow collides with the web is reduced, and the fibers are not sufficiently entangled three-dimensionally. Are not preferred. This high-pressure liquid flow treatment may be either a continuous step or a separate step. In order to remove excess moisture from the web after the high-pressure liquid flow treatment, a known method can be adopted. For example, the remaining moisture is removed using a squeezing device such as a mangle roll, and then dried using a drying unit such as a hot air dryer.

[0021]

In the short fiber nonwoven fabric of the present invention, the short fibers constituting the nonwoven fabric have a core-in-sheath composite structure, and the core component is composed of a polyalkylene oxide modified product or a mixture of this modified product and polyamide or polyester. Moisture absorption and release properties are imparted to the nonwoven fabric, and the sheath component is made of polyamide or polyester, so that the short fiber has a good spinnability and strength.
Therefore, the strength of the nonwoven fabric is improved. The modified polyalkylene oxide in the core component is obtained by reacting a polyalkylene oxide and a polyol with a symmetric aliphatic isocyanate compound, and has an isocyanate group such as that observed when an aromatic isocyanate compound is used. As a result of suppressing the yellowing caused by the imide ring formed by the resonance structure with the aromatic ring, the fibers do not yellow even after long-term use, and therefore have excellent weather resistance. Furthermore, this nonwoven fabric has mechanical properties such as shape retention, strength and dimensional stability because the constituent fibers are heat-pressed in the partial heat-pressing area, or the constituent fibers are three-dimensionally entangled with each other. Therefore, it has mechanical properties such as shape retention and practically sufficient strength and flexibility.

[0022]

Next, the present invention will be described specifically with reference to examples. In addition, the measurement and evaluation method in each example are as follows. Relative viscosity of polyamide (a): Measured 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 96% by weight as a solvent. Relative viscosity of polyester (b): 0.5 g of sample concentration using a mixed solution of phenol and ethane tetrachloride in equal weight as solvent
/ 100 cc and a temperature of 20 ° C. were measured by a conventional method. Melt viscosity of modified polyalkylene oxide: 1.5 g of modified polyalkylene oxide was used as a measurement sample, and using a flow tester (CFT-500D manufactured by Shimadzu Corporation), the die diameter was 1 mm, the die length was 1 mm, and the applied load was 50 kg /. cm
^{2. The} melt viscosity (poise) was measured at a measurement temperature of 170 ° C. Water absorption capacity of modified polyalkylene oxide: 200 pure water
1 g of the polyalkylene oxide-modified product weighed in cc was added, and the mixture was stirred for 24 hours, and then filtered through a 200-mesh wire gauze. The weight of the obtained gel after filtration was determined as the water absorption capacity [g (pure water) / g ( Polymer)]. Fabric weight of nonwoven fabric: Ten points each of 10 cm × 10 cm sample pieces were prepared from the nonwoven fabric in a standard state, and after reaching equilibrium moisture, the weight (g) of each sample piece was weighed, and the average of the obtained values was obtained. Convert the value to per unit area and weight (g / m ² )
And Tensile strength of nonwoven fabric: Tensile strength was measured according to the method described in JIS-L-1096A. That is, ten test pieces each having a sample length of 20 cm and a sample width of 2.5 cm were prepared, and a constant-speed elongation type tensile tester (Tensilon manufactured by Toyo Baldwin Co., Ltd.) was used for each sample piece in the warp and weft directions of the nonwoven fabric. Using UTM-4-1-100), the sample was stretched at a gripping interval of 10 cm and a pulling speed of 10 cm / min, and the average value of the obtained load values at cutting (g / 2.5 cm width) was determined as the tensile strength (g / g). 2.5 cm width). Bending softness of nonwoven fabric: A total of five specimens each having a sample length of 10 cm and a specimen width of 5 cm were prepared, and each specimen was bent in the lateral direction to form a cylindrical body. Machine (Tensilon UTM-4- manufactured by Toyo Baldwin Co., Ltd.)
Using 1-100), compression was performed at a compression speed of 5 cm / min, and the average value of the obtained maximum load values (g) was defined as the softness (g) of the nonwoven fabric. Moisture Absorption and Desorption of Nonwoven Fabric: The moisture absorption and desorption of the nonwoven fabric was evaluated based on the moisture content M0, M1 and M2 shown by the following formulas (1), (2) and (3). First, the moisture content was determined as follows: sample length 10 cm, sample width 10
cm of the sample was dried at 105 ° C. for 2 hours and weighed W0.
(G), and then humidified under the conditions of a temperature of 25 ° C. and a relative humidity of 60% for 2 hours to measure the weight W1 (g), and the initial moisture content M0 (% by weight) is calculated by the following equation (1). I asked. Next, the sample was allowed to absorb moisture for 24 hours at a temperature of 34 ° C. and a relative humidity of 90%, and then the weight W2 (g) was measured, and the water content M1 (% by weight) was determined by the following equation (2). Thereafter, this sample was further subjected to a temperature of 25 ° C. and a relative humidity of 60% for an additional 2 hours.
After standing for 4 hours, the weight W3 (g) was measured, and the moisture content M2 (% by weight) after dehumidification was determined by the following equation (3). M0 (% by weight) = [(W1−W0) / W0] × 100 (1) M1 (% by weight) = [(W2−W0) / W0] × 100 (2) M2 (% by weight) = [(W3− W0) / W0] × 100 (3) Weather resistance of non-woven fabric: JIS-K after exposing a sample having a sample length of 10 cm and a sample width of 10 cm to an outdoor natural environment for 30 days.
The degree of yellowing was measured according to the method described in -7103 and used as an index of weather resistance. That is, tristimulus (X, Y,
Z) with a color difference meter (color-eye 31 manufactured by Macbeth Co., Ltd.)
00), the yellowness (YI) is calculated according to the following formula (4), and the difference (△ YI) between the yellowness before and after exposure to the outdoor natural environment in the following formula (5) is calculated as yellow. The degree of change. YI = 100 (1.28X-1.06Z) / Y (4) ΔYI = YI-YI0 (5) YI: Yellowing degree after exposure for 30 days outdoors YI0: Yellow before exposure for 30 days outdoors Degree of change

Example 1 Nylon 6 having a relative viscosity (a) of 2.6 as a sheath component, nylon 6 having a relative viscosity of 2.6 and a modified polyalkylene oxide having a water absorption capacity of 35 g / g and a melt viscosity of 4000 poise. [(Nylon 6 / modified polyalkylene oxide) (weight ratio) = 85/15] as a core component, and a sheath / core composite weight ratio of 50/50 to obtain a concentric core-sheath type composite fiber yarn. After melt spinning and stretching, mechanical crimping was applied and cut into a predetermined length to produce short fibers. The polyalkylene oxide modified product has a weight average molecular weight of 20,000.
Of polyethylene oxide, 1,4-butanediol, and dicyclohexylmethane-4,4'-diisocyanate. That is, after each of the polymers is melted, melt spinning is performed at a spinning temperature of 260 ° C. through a composite spinneret at a single hole discharge rate of 1.04 g / min.
After cooling the spun yarn with a known cooling device, it was wound at a winding speed of 1200 m / min to obtain an undrawn yarn. Next, a plurality of the obtained undrawn yarns are combined, thermally drawn at a temperature of 60 ° C. and a draw ratio of 2.6, and then subjected to mechanical crimping of 22 crimps / 25 mm in a stuffing box. , Fiber length 5
It was cut to 1 mm to obtain short fibers having a single yarn fineness of 3.0 denier. Next, the short fibers are carded by using a random card machine to form a web, and then the nonwoven web is subjected to a partial hot pressing process using a hot pressing device to obtain a nonwoven fabric having a basis weight of 50 g / m ² . Obtained. In this heat-pressure welding process, the protrusion having an area of 0.6 mm ² has a pressure contact density of 20 points / c.
The treatment temperature, that is, the surface temperature of the embossing roll and the surface of the metal roll, was set to 190 ° C. using an apparatus composed of a heated embossing roll and a heated metal roll having a smooth surface provided at m ² and a pressed area ratio of 13.2%. Table 1 shows the strength, the softness, the moisture absorption / release property, and the weather resistance of the obtained nonwoven fabric.

Examples 2 to 4 Non-woven fabrics were obtained in the same manner as in Example 1 except that the mixing ratio of nylon 6 and the modified polyalkylene oxide in the core component was changed as shown in Table 1. Table 1 shows the strength, the softness, the moisture absorption / release property, and the weather resistance of the obtained nonwoven fabric.

Example 5 A modified polyalkylene oxide compounded in the core component is obtained by reacting polyethylene oxide having a weight average molecular weight of 20,000, 1,4-butanediol, and 1,6-hexamethylene diisocyanate. Example 1 except that a modified polyalkylene oxide having a water absorption capacity of 33 g / g and a melt viscosity of 5000 poise was employed.
In the same manner as in the above, a nonwoven fabric was obtained. The strength of the obtained nonwoven fabric,
Table 1 shows the hardness, moisture absorption / release properties, and weather resistance.

Example 6 As a modified polyalkylene oxide compounded in the core component, an ethylene oxide / propylene oxide copolymer having a weight average molecular weight of 20,000 (50% by weight) and a weight average molecular weight of 15,000 (molar ratio: 80
/ 20) Polyalkylene oxide having a water absorption capacity of 36 g / g and a melt viscosity of 1000 poise obtained by reacting a 50% by weight mixture with 1,4-butanediol and dicyclohexylmethane-4,4'-diisocyanate. A nonwoven fabric was obtained in the same manner as in Example 1 except that the modified product was used. The strength, flexibility and moisture absorption and desorption of the obtained nonwoven fabric,
Table 1 shows the weather resistance.

Example 7 As a modified polyalkylene oxide compounded in the core component, a mixture of 50% by weight of polyethylene oxide having a weight average molecular weight of 15,000 and 50% by weight of polypropylene oxide having a weight average molecular weight of 4,000, and 1,4-butane The water absorption capacity obtained by reacting a diol with dicyclohexylmethane-4,4'-diisocyanate is 28 g /
A nonwoven fabric was obtained in the same manner as in Example 1 except that a modified polyalkylene oxide having a melt viscosity of 20,000 poise in g was employed. Table 1 shows the strength, the softness, the moisture absorption / release property, and the weather resistance of the obtained nonwoven fabric.

Example 8 After the short fibers obtained in Example 2 were carded using a random card machine to form a web, the nonwoven web was placed on a 70 mesh wire mesh moving at a moving speed of 20 m / min. And subject it to high-pressure liquid flow treatment, remove excess water from the resulting treated material using a mangle roll, apply a drying treatment to the treated material using a hot-air dryer, and three-dimensionally entangle the constituent fibers. A nonwoven fabric having a basis weight of 50 g / m ² was obtained. In the high-pressure liquid flow treatment, a high-pressure columnar water flow treatment device in which injection holes having a hole diameter of 0.1 mm are arranged in a line at a hole interval of 0.6 mm is used. The columnar water flow is divided into two stages from a position 50 mm above the web. Acted. In the first stage processing, the pressure is 30 kg / cm ² G, and in the second stage processing, the pressure is 70 k / cm ² G.
g / cm ² G. Then, the processing in the second stage was first performed four times from the front side of the web, then reversed the web, and performed five times from the rear side. In the drying treatment of the web after the treatment, the treatment temperature was set to 85. Table 1 shows the strength, the softness, the moisture absorption / release property, and the weather resistance of the obtained nonwoven fabric.

Examples 9 and 10 Non-woven fabrics were obtained in the same manner as in Example 8 except that the mixing ratio of nylon 6 and the modified polyalkylene oxide in the core component was changed as shown in Table 1. Table 1 shows the strength, the softness, the moisture absorption / release property, and the weather resistance of the obtained nonwoven fabric.

Comparative Example 1 A mixture of nylon 6 and a polyalkylene oxide modified product ((nylon 6 / polyalkylene oxide modified product) (weight ratio) = 95/5) was used as a core component. The content of the alkylene oxide-modified product is 2.
A nonwoven fabric was obtained in the same manner as in Example 1 except that the amount was 5% by weight. The strength, flexibility and moisture absorption and desorption of the obtained nonwoven fabric,
Table 1 shows the weather resistance.

Comparative Example 2 A mixture of nylon 6 and a polyalkylene oxide modified product ((nylon 6 / polyalkylene oxide modified product) (weight ratio) = 30/70) was used as a core component. When the content of the alkylene oxide-modified product is 3
An attempt was made to produce a nonwoven fabric in the same manner as in Example 1 except that the content was 5% by weight.

Comparative Example 3 As a modified polyalkylene oxide compounded in the core component, polyethylene oxide having a weight average molecular weight of 20,000, 1,4-butanediol and 4,4′-symmetric aromatic isocyanate compound The water absorption capacity obtained by reacting with diphenylmethane diisocyanate is 32
A nonwoven fabric was obtained in the same manner as in Example 1 except that a modified polyalkylene oxide having a melt viscosity of 5000 poise at g / g was employed. Table 1 shows the strength, the softness, the moisture absorption / release property, and the weather resistance of the obtained nonwoven fabric.

Comparative Example 4 As a modified polyalkylene oxide compounded in the core component, an ethylene oxide / propylene oxide copolymer having a weight average molecular weight of 20,000 (25% by weight) and a weight average molecular weight of 15,000 (molar ratio: 80
/ 20) Polyalkylene oxide having a water absorption capacity of 43 g / g and a melt viscosity of 600 poise obtained by reacting a 75% by weight mixture with 1,4-butanediol and dicyclohexylmethane-4,4'-diisocyanate. A nonwoven fabric was obtained in the same manner as in Example 1 except that the modified product was used. Table 1 shows the strength, the softness, the moisture absorption / release property, and the weather resistance of the obtained nonwoven fabric.

Comparative Example 5 As a modified polyalkylene oxide compounded in the core component, a mixture of 50% by weight of polyethylene oxide having a weight average molecular weight of 11,000 and 50% by weight of polypropylene oxide having a weight average molecular weight of 4,000, and 1,4-butane The water absorption capacity obtained by reacting a diol with dicyclohexylmethane-4,4'-diisocyanate is 30 g /
The production of a nonwoven fabric was attempted in the same manner as in Example 1 except that a modified polyalkylene oxide having a melt viscosity of 35,000 poise in g was employed.

[0035]

[Table 1]

In the nonwoven fabrics obtained in Examples 1 to 10, the constituent short fibers were all composed of polyamide as a sheath component and a mixture of polyamide and a polyalkylene oxide modified product as a core component. The modified polyalkylene oxide compounded was at a temperature of 170 ° C. and an applied load of 50 kg /
It is a solvent-soluble polymer having a melt viscosity in the range of 1,000 to 20,000 poise at the time of cm ² , and its ratio to the whole fiber is in the range of 5 to 30% by weight. It was also excellent in moisture absorption / release properties. Further, since this polyalkylene oxide-modified product is obtained by reacting a polyalkylene oxide and a polyol with a symmetric aliphatic isocyanate compound,
The obtained nonwoven fabric was excellent in weather resistance. On the other hand, the nonwoven fabric obtained in Comparative Example 1 had a low proportion of the polyalkylene oxide-modified product in the whole fiber, and was poor in moisture absorption / release properties. Further, in Comparative Example 2, the proportion of the polyalkylene oxide-modified product in the whole fiber was too high, so that the spinnability deteriorated and short fibers could not be obtained. The nonwoven fabric obtained in Comparative Example 3 was poor in weather resistance because a polyalkylene oxide-modified product using an asymmetric aliphatic isocyanate compound was employed.
In the nonwoven fabric obtained in Comparative Example 4, the melt viscosity of the polyalkylene oxide-modified product was too low, so the strength was low due to the low strength of the fiber, and the practicality was poor. In Comparative Example 5, since the melt viscosity of the polyalkylene oxide-modified product was too high, the spinnability deteriorated and short fibers could not be obtained.

Example 11 Nylon 6 having a relative viscosity (a) of 2.6 was used as a sheath component, and only the polyalkylene oxide-modified product used in Example 1 was used as a core component, and the sheath / core composite weight ratio was 92.5 / 7.5 (Ratio of polyalkylene oxide-modified product to total fiber is 7.5.
5% by weight), and a concentric core-sheath composite fiber yarn was melt-spun to produce a short-fiber nonwoven fabric. That is, after the nylon 6 was melted at a temperature of 250 ° C. and the modified polyalkylene oxide was melted at a temperature of 150 ° C., the spinning temperature was 26 ° C.
Melt spinning was performed at 0 ° C. via a composite spinneret, and thereafter, a nonwoven fabric was obtained in the same manner as in Example 1. Table 2 shows the strength, the softness, the moisture absorption / release property, and the weather resistance of the obtained nonwoven fabric.

Examples 12 to 14 Non-woven fabrics were obtained in the same manner as in Example 11 except that the ratio of the polyalkylene oxide-modified product in the whole fiber was changed as shown in Table 2. Table 2 shows the strength, the softness, the moisture absorption / release property, and the weather resistance of the obtained nonwoven fabric.

Example 15 A nonwoven fabric was obtained in the same manner as in Example 11 except that the modified polyalkylene oxide used in Example 5 was used as a core component. Table 2 shows the strength, the softness, the moisture absorption / release property, and the weather resistance of the obtained nonwoven fabric.

Example 16 A nonwoven fabric was obtained in the same manner as in Example 11, except that the modified polyalkylene oxide used in Example 6 was used as a core component. Table 2 shows the strength, the softness, the moisture absorption / release property, and the weather resistance of the obtained nonwoven fabric.

Example 17 A nonwoven fabric was obtained in the same manner as in Example 11, except that the modified polyalkylene oxide used in Example 7 was used as a core component. Table 2 shows the strength, the softness, the moisture absorption / release property, and the weather resistance of the obtained nonwoven fabric.

Examples 18 to 20 Non-woven fabrics were obtained in the same manner as in Example 11, except that the mixing ratio of the modified polyalkylene oxide in the core component was changed as shown in Table 2. Table 2 shows the strength, the softness, the moisture absorption / release property, and the weather resistance of the obtained nonwoven fabric.

Comparative Example 6 The procedure of Example 1 was repeated except that the core component was constituted only by the polyalkylene oxide-modified product used in Example 1, and the content of the polyalkylene oxide-modified product in the whole fiber was 2.5% by weight. In the same manner as in Example 11, a nonwoven fabric was obtained. Table 2 shows the strength, the softness, the moisture absorption / release property, and the weather resistance of the obtained nonwoven fabric.

Comparative Example 7 Example 11 was repeated except that the core component was constituted only by the polyalkylene oxide-modified product used in Example 1, and the content of the polyalkylene oxide-modified product in the whole fiber was 35% by weight. In the same manner as described above, production of a nonwoven fabric was attempted.

Comparative Example 8 A nonwoven fabric was obtained in the same manner as in Example 11, except that the modified polyalkylene oxide used in Comparative Example 3 was used as the core component. Table 2 shows the strength, the softness, the moisture absorption / release property, and the weather resistance of the obtained nonwoven fabric.

Comparative Example 9 A nonwoven fabric was obtained in the same manner as in Example 11, except that the modified polyalkylene oxide used in Comparative Example 4 was used as the core component. Table 2 shows the strength, the softness, the moisture absorption / release property, and the weather resistance of the obtained nonwoven fabric.

Comparative Example 10 A nonwoven fabric was produced in the same manner as in Example 11, except that the modified polyalkylene oxide used in Comparative Example 5 was used as the core component.

[0048]

[Table 2]

The nonwoven fabrics obtained in Examples 11 to 20 had a core component composed of only the modified polyalkylene oxide, but had high mechanical performance such as strength, and excellent in moisture absorption / desorption property and weather resistance. there were. On the other hand, the nonwoven fabric obtained in Comparative Example 6 had a low ratio of the polyalkylene oxide-modified product in the whole fiber, and was poor in moisture absorption / release properties. In Comparative Example 7, the proportion of the polyalkylene oxide-modified product in the whole fiber was too high, and the spinnability deteriorated, and short fibers could not be obtained. The nonwoven fabric obtained in Comparative Example 8 was poor in weather resistance because a polyalkylene oxide-modified product using an asymmetric aliphatic isocyanate compound was employed. The nonwoven fabric obtained in Comparative Example 9 was
Since the melt viscosity of the polyalkylene oxide-modified product was too low, the strength was low due to the low strength of the fiber, and the practicality was poor. In Comparative Example 10, the melt viscosity of the polyalkylene oxide-modified product was too high, so that the spinnability deteriorated.
Short fibers could not be obtained.

Example 21 Polyethylene terephthalate having a relative viscosity (b) of 1.38 as a sheath component, a mixture of polyethylene terephthalate having a relative viscosity (b) of 1.38 and the modified polyalkylene oxide used in Example 1 [ (Modified polyethylene terephthalate / polyalkylene oxide) (weight ratio) = 85
/ 15] as a core component and a sheath / core composite weight ratio of 50/50.
A concentric core-sheath composite fiber yarn was melt-spun, stretched, mechanically crimped, and cut into a predetermined length to produce short fibers. That is, after each of the above polymers was melted, it was melt spun at a spinning temperature of 290 ° C. through a composite spinneret at a single hole discharge rate of 1.28 g / min, and the spun yarn was cooled by a known cooling device. Thereafter, it was wound at a winding speed of 1200 m / min to obtain an undrawn yarn. Next, a plurality of the obtained undrawn yarns are combined and hot drawn at a temperature of 90 ° C. and a draw ratio of 3.2.
After heat-treating at 60 ° C., mechanical crimping of 22 crimps / 25 mm was performed in a stuffing box.
It was cut to 1 mm to obtain short fibers having a single yarn fineness of 3.0 denier. Next, the short fibers are carded by using a random card machine to form a web, and then the nonwoven web is subjected to a partial hot pressing process using a hot pressing device to obtain a nonwoven fabric having a basis weight of 50 g / m ² . Obtained. At the time of this thermal pressure welding, the apparatus used in Example 1 was used, and the processing temperature, that is, the surface temperature of the embossing roll and the metal roll was set to 245 ° C. Table 3 shows the strength, bristles, moisture absorption / release properties, and weather resistance of the obtained nonwoven fabric.

Examples 22 to 24 Non-woven fabrics were obtained in the same manner as in Example 21 except that the mixing ratio of the polyethylene terephthalate and the modified polyalkylene oxide in the core component was changed as shown in Table 3. Table 3 shows the strength, bristles, moisture absorption / release properties, and weather resistance of the obtained nonwoven fabric.

Example 25 A non-woven fabric was obtained in the same manner as in Example 21 except that the modified polyalkylene oxide used in Example 5 was used as the modified polyalkylene oxide to be added to the core component. Table 3 shows the strength, bristles, moisture absorption / release properties, and weather resistance of the obtained nonwoven fabric.

Example 26 A nonwoven fabric was obtained in the same manner as in Example 21 except that the modified polyalkylene oxide used in Example 6 was used as the modified polyalkylene oxide to be mixed with the core component. Table 3 shows the strength, bristles, moisture absorption / release properties, and weather resistance of the obtained nonwoven fabric.

Example 27 A nonwoven fabric was obtained in the same manner as in Example 21 except that the modified polyalkylene oxide used in Example 7 was used as the modified polyalkylene oxide to be mixed with the core component. Table 3 shows the strength, bristles, moisture absorption / release properties, and weather resistance of the obtained nonwoven fabric.

Examples 28 to 30 Non-woven fabrics were obtained in the same manner as in Example 21 except that the mixing ratio of the modified polyalkylene oxide in the core component was changed as shown in Table 3. Table 3 shows the strength, bristles, moisture absorption / release properties, and weather resistance of the obtained nonwoven fabric.

Comparative Example 11 Mixture of polyethylene terephthalate and modified polyalkylene oxide [(polyethylene terephthalate / modified polyalkylene oxide) (weight ratio) = 95 /
5)] was used as a core component, and thus a nonwoven fabric was obtained in the same manner as in Example 21 except that the content of the polyalkylene oxide-modified product in the fiber was 2.5% by weight. Table 3 shows the strength, softness, moisture absorption / desorption property, and weather resistance of the obtained nonwoven fabric.
Shown in

Comparative Example 12 Mixture of polyethylene terephthalate and modified polyalkylene oxide [(polyethylene terephthalate / polyalkylene oxide modified) (weight ratio) = 30/7
0)] was used as the core component, and thus the production of a nonwoven fabric was attempted in the same manner as in Example 21 except that the content of the polyalkylene oxide-modified product in the fiber was 35% by weight. Table 3 shows the strength, bristles, moisture absorption / release properties, and weather resistance of the obtained nonwoven fabric.

Comparative Example 13 A nonwoven fabric was obtained in the same manner as in Example 21 except that the modified polyalkylene oxide used in Comparative Example 3 was used as the modified polyalkylene oxide to be mixed with the core component. Table 3 shows the strength, bristles, moisture absorption / release properties, and weather resistance of the obtained nonwoven fabric.

Comparative Example 14 A nonwoven fabric was obtained in the same manner as in Example 21 except that the modified polyalkylene oxide used in Comparative Example 4 was used as the modified polyalkylene oxide to be mixed with the core component. Table 3 shows the strength, bristles, moisture absorption / release properties, and weather resistance of the obtained nonwoven fabric.

Comparative Example 15 Production of a nonwoven fabric was attempted in the same manner as in Example 21 except that the modified polyalkylene oxide used in Comparative Example 5 was used as the modified polyalkylene oxide to be mixed with the core component.

[0061]

[Table 3]

The nonwoven fabrics obtained in Examples 21 to 30 each had a short fiber composed of polyethylene terephthalate as a sheath component and a mixture of polyethylene terephthalate and a modified polyalkylene oxide as a core component. The modified polyalkylene oxide compounded as a component is a solvent-soluble polymer having a melt viscosity in the range of 1,000 to 20,000 poise at a temperature of 170 ° C. and an applied load of 50 kg / cm ² , and has a ratio of 5 to the total fiber. Since the content was in the range of 30 to 30% by weight, mechanical properties such as strength were high, and excellent in moisture absorption / release properties. Moreover, since the polyalkylene oxide-modified product was obtained by reacting a polyalkylene oxide and a polyol with a symmetric aliphatic isocyanate compound, the obtained nonwoven fabric was excellent in weather resistance. On the other hand, in the nonwoven fabric obtained in Comparative Example 11, the ratio of the polyalkylene oxide-modified product in the whole fiber was low, and the nonwoven fabric had poor moisture absorption / release properties. In Comparative Example 12, the proportion of the polyalkylene oxide-modified product in the whole fiber was too high, and the spinnability deteriorated, and short fibers could not be obtained. The nonwoven fabric obtained in Comparative Example 13 was inferior in weather resistance because a polyalkylene oxide-modified product using an asymmetric aliphatic isocyanate compound was employed. Comparative Example 1
In the nonwoven fabric obtained in No. 4, the melt viscosity of the polyalkylene oxide-modified product was too low, so the strength was low due to the low strength of the fiber, and the practicality was poor. In Comparative Example 15, the melt viscosity of the polyalkylene oxide-modified product was too high, so that the spinnability deteriorated and short fibers could not be obtained.

Example 31 Polyethylene terephthalate having a relative viscosity (b) of 1.38 was used as a sheath component, and only the polyalkylene oxide-modified product used in Example 1 was used as a core component, and the sheath / core composite weight ratio was 92.0%.
A concentric core-sheath type composite fiber yarn was melt-spun as 5 / 7.5 (the ratio of the polyalkylene oxide-modified product in the whole fiber was 7.5% by weight) to produce a short-fiber nonwoven fabric.
That is, the polyethylene terephthalate is treated at a temperature of 28.
At 0 ° C. and at a temperature of 15 ° C.
After each was melted at 0 ° C., it was melt spun through a composite spinneret at a spinning temperature of 290 ° C., and thereafter, a nonwoven fabric was obtained in the same manner as in Example 21. Table 4 shows the strength, the softness, the moisture absorption / release properties, and the weather resistance of the obtained nonwoven fabric.

Examples 32 to 34 Non-woven fabrics were obtained in the same manner as in Example 31 except that the ratio of the polyalkylene oxide-modified product in the whole fiber was changed as shown in Table 4. Table 4 shows the strength, the softness, the moisture absorption / release properties, and the weather resistance of the obtained nonwoven fabric.

Example 35 A nonwoven fabric was obtained in the same manner as in Example 31 except that the polyalkylene oxide-modified product used in Example 5 was used as a core component. Table 4 shows the strength, the softness, the moisture absorption / release properties, and the weather resistance of the obtained nonwoven fabric.

Example 36 A non-woven fabric was obtained in the same manner as in Example 31 except that the modified polyalkylene oxide used in Example 6 was used as a core component. Table 4 shows the strength, the softness, the moisture absorption / release properties, and the weather resistance of the obtained nonwoven fabric.

Example 37 A nonwoven fabric was obtained in the same manner as in Example 31 except that the polyalkylene oxide-modified product used in Example 7 was used as a core component. Table 4 shows the strength, the softness, the moisture absorption / release properties, and the weather resistance of the obtained nonwoven fabric.

Examples 38 to 40 Non-woven fabrics were obtained in the same manner as in Example 31 except that the mixing ratio of the modified polyalkylene oxide in the core component was changed as shown in Table 4. Table 4 shows the strength, the softness, the moisture absorption / release properties, and the weather resistance of the obtained nonwoven fabric.

COMPARATIVE EXAMPLE 16 The procedure of Example 21 was repeated except that the core component was constituted only by the polyalkylene oxide-modified product used in Example 21 and the content of the polyalkylene oxide-modified product in the whole fiber was 2.5% by weight. In the same manner as in Example 31, a nonwoven fabric was obtained. Table 4 shows the strength, the softness, the moisture absorption / release properties, and the weather resistance of the obtained nonwoven fabric.

Comparative Example 17 Example 31 was the same as Example 31 except that the core component was constituted only by the polyalkylene oxide-modified product used in Example 21 and the content of the polyalkylene oxide-modified product in the whole fiber was 35% by weight. In the same manner as described above, production of a nonwoven fabric was attempted.

Comparative Example 18 A non-woven fabric was obtained in the same manner as in Example 31, except that the modified polyalkylene oxide used in Comparative Example 3 was used as the core component. Table 4 shows the strength, the softness, the moisture absorption / release properties, and the weather resistance of the obtained nonwoven fabric.

Comparative Example 19 A nonwoven fabric was obtained in the same manner as in Example 31 except that the polyalkylene oxide-modified product used in Comparative Example 4 was used as a core component. Table 4 shows the strength, the softness, the moisture absorption / release properties, and the weather resistance of the obtained nonwoven fabric.

Comparative Example 20 A nonwoven fabric was produced in the same manner as in Example 31 except that the modified polyalkylene oxide used in Comparative Example 5 was used as the core component.

[0074]

[Table 4]

The non-woven fabrics obtained in Examples 31 to 40 had a core component composed of only the modified polyalkylene oxide, but had high mechanical performance such as strength, and excellent in moisture absorption / desorption property and weather resistance. there were. On the other hand, the nonwoven fabric obtained in Comparative Example 16 had a low proportion of the polyalkylene oxide-modified product in the entire fiber, and was poor in moisture absorption / release properties.
In Comparative Example 17, the proportion of the polyalkylene oxide-modified product in the whole fiber was too high, and the spinnability deteriorated, and short fibers could not be obtained. The nonwoven fabric obtained in Comparative Example 18 was inferior in weather resistance because a polyalkylene oxide-modified product using an asymmetric aliphatic isocyanate compound was employed. In the nonwoven fabric obtained in Comparative Example 19, since the melt viscosity of the polyalkylene oxide-modified product was too low, the strength was low due to the low strength of the fiber, and the practicality was poor. In Comparative Example 20, since the melt viscosity of the polyalkylene oxide-modified product was too high, the spinnability deteriorated and short fibers could not be obtained.

[0076]

According to the short fiber nonwoven fabric of the present invention, the short fibers constituting the nonwoven fabric have a core-sheath type composite structure, and the core component is composed of a polyalkylene oxide modified product or a mixture of the modified product and a polyamide or polyester. The moisture absorption and release properties are imparted to the non-woven fabric from the fact that the sheath component is composed of polyamide or polyester, so that the fiber-forming properties and strength of short fibers can be improved.
Therefore, the strength of the nonwoven fabric is improved. Further, the modified polyalkylene oxide in the core component is obtained by reacting a polyalkylene oxide and a polyol with a symmetric aliphatic isocyanate compound. It will be excellent in property.
Furthermore, this nonwoven fabric has mechanical properties such as shape retention, strength and dimensional stability because the constituent fibers are heat-pressed in the partial heat-pressing area, or the constituent fibers are three-dimensionally entangled with each other. Therefore, it has mechanical properties such as shape retention and practically sufficient strength and flexibility. This long-fiber nonwoven fabric can be suitably used for sanitary materials, general living related materials, industrial materials, and the like.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Yoshitaka Nagara 23 Uji Kozakura, Uji-city, Kyoto F Unit in Central Research Laboratory of Unitika Ltd. 4L047 AA21 AA23 AA27 AB02 BA04 BA08 BD04 CA15 CA19 CB01 CB08 CC03

Claims (6)

[Claims] 1. A core-sheath composite structure comprising a polyamide or polyester as a sheath component and a polyalkylene oxide modified product obtained by reacting a polyalkylene oxide and a polyol with a symmetric aliphatic isocyanate compound as a core component. Wherein the modified polyalkylene oxide of the core component is composed of short fibers in an amount of 5 to 30% by weight based on the weight of the fibers, and maintains a predetermined shape by partial heat welding. Hygroscopic short fiber nonwoven fabric. 2. A mixture comprising a polyamide or polyester as a sheath component and a polyalkylene oxide modified product obtained by reacting a polyalkylene oxide and a polyol with a symmetric aliphatic isocyanate compound as a core component, and a polyamide or polyester. Having a core-in-sheath type composite structure and the core component is composed of short fibers in which the polyalkylene oxide-modified product is 5 to 30% by weight based on the weight of the fiber, and maintains a predetermined shape by partial heat welding. A moisture-absorbing and desorbing short-fiber nonwoven fabric, characterized in that: 3. A core-sheath composite structure comprising a polyamide or polyester as a sheath component and a polyalkylene oxide modified product obtained by reacting a polyalkylene oxide and a polyol with a symmetric aliphatic isocyanate compound as a core component. And that the polyalkylene oxide-modified product of the core component is composed of short fibers in an amount of 5 to 30% by weight based on the weight of the fibers, and retains a predetermined shape by three-dimensional entanglement between the fibers. Characteristic non-woven fabric that absorbs and releases moisture. 4. A mixture of a polyamide or polyester, wherein the sheath component is a polyamide or polyester, and the core component is a polyalkylene oxide modified product obtained by reacting a polyalkylene oxide and a polyol with a symmetric aliphatic isocyanate compound. Having a core-in-sheath type composite structure, wherein the core component polyalkylene oxide-modified product is composed of short fibers in an amount of 5 to 30% by weight based on the weight of the fibers. A moisture-absorbing and desorbing short-fiber nonwoven fabric, which retains its shape. 5. The nonwoven fabric of claim 1, 2, 3 or 4, wherein the symmetric aliphatic isocyanate compound is dicyclohexylmethane-4,4′-diisocyanate or 1,6-hexamethylene diisocyanate. 6. The modified polyalkylene oxide has a melt viscosity of 1,000 to 20,000 poise at a temperature of 170 ° C. and an applied load of 50 kg / cm ² .
6. The moisture-absorbing and releasing short-fiber nonwoven fabric according to 3, 4 or 5.