JPH06330449A - Elastic non-woven fabric excellent in water absorbability and fast dryness - Google Patents

Abstract

PURPOSE:To obtain a water-absorbable and fast drying non-woven fabric excellent in flexibility and shrinkage recovery property by adhering silk protein to a non-woven fabric comprising polyurethane filaments and a non-elastic fibers distributed in a loop-like state. CONSTITUTION:The shrinkable non-woven fabric excellent in water absorbability and fast drying is produced by spinning a thermoplastic polyurethane polymer and a polyethylene glycol-copolymerized polyethylene terephthalate polymer into split type conjugate fibers, finely dividing the split type conjugate fibers with an air sucker, simultaneously accumulating the divided fibers on a collection conveyer to form a fiber sheet in which the interlacing points of the conjugate filaments are fused with the polyurethane component, repeatedly subjecting the fiber sheet to shrinking treatments in hot water for the division of the conjugate fibers constituting the sheet to form an elastic non-woven fabric in which the copolyester non-elastic fibers having a single fiber fineness of <=1dl are laminated in a loop-like state loosed in lengths of two times or more the non-tension length of the polyurethane elastic fibers between their jointed points, immersing the non-woven fabric in a silk-dispersed urethane resin emulsion, and subsequently treating the treated non-woven fabric with high temperature steam.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stretchable nonwoven fabric which is excellent in water absorption and quick drying.

[0002]

2. Description of the Related Art Generally, a fiber material obtained by fixing silk protein to a woven or knitted cloth is used as a shirt, a blouse, a sportswear material or the like, but most of them are not stretchable (Japanese Patent Laid-Open No. HEI 5). -78997). On the other hand, there have been various attempts such as direct flocking on a stretchable cloth or lamination of a polyurethane elastic nonwoven fabric and a cloth in order to obtain a stretchable flocked cloth. It was unavoidable that the permeation impaired the elasticity and the texture became rough and rigid.

Japanese Unexamined Patent Publication (Kokai) No. 2-264057 discloses an elastic nonwoven fabric obtained by mixing melt-blown ultrafine fibers of a saponified ethylene-vinyl acetate copolymer (hereinafter referred to as EVOH) and meltblown ultrafine fibers of polyurethane. Since the average fiber diameter is 8 μm or less and the ethylene-vinyl acetate component is heat-bonded, it is undeniable that the paper-like composition is inferior in elasticity and texture.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a water-absorbing / quick-drying nonwoven fabric which is flexible and has excellent elongation recovery, and a method for producing the same, which solves the conventional defects.

[0005]

[Means for Solving the Problems] That is, the nonwoven fabric of the present invention is
A non-woven fabric comprising a fibrous sheet in which a polyurethane filament (A) and an inelastic fiber (B) are laminated, and a silk protein is fixed to the polyurethane filament (A).
It is fused by itself, and the non-elastic fiber (B) is laminated in a length that is at least twice the length of the polyurethane filament (A) under no tension between the joining points. And

Further, the nonwoven fabric of the present invention has a shape in which both the thermoplastic fiber-forming polyurethane elastic body (a) and the thermoplastic fiber-forming non-elastic polymer (b) are exposed on the outer peripheral surface of the fiber in the longitudinal direction. The composite filaments (D) that are bonded to each other are laminated without being substantially converged, and the joint points of the laminated composite filaments (D) are fused by the polyurethane elastic body (a) itself. A step of producing a fibrous sheet, a step of dividing the composite filament (D) constituting the fibrous sheet into a polyurethane filament (A) and an inelastic fiber (B), and stretching the fibrous sheet to produce the inelastic fiber (B) Manufactured by the step of stretching and the step of fixing silk protein to the fiber sheet.

The thermoplastic fiber-forming polyurethane elastic body (a) used for the composite filament (D) and the polyurethane elastic filament (A) constituting the fiber sheet may be any known melt-spinnable polyurethane elastic body. Not limited.

Such a polyurethane elastic material is usually a low melting point polyol having a molecular weight of 500 to 6000, such as dihydroxypolyether, dihydroxypolyester, dihydropolycarbonate, dihydroxypolyesteramide, and an organic diisocyanate having a molecular weight of 500 or less,
For example, p, p'-diphenylmethane diisocyanate, tolylene diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, xylylene diisocyanate, 2,6-diisocyanate methylcaproate, hexamethylene diisocyanate, and chain extenders having a molecular weight of 500 or less, for example, It is a polymer obtained by reaction with glycol, aminoalcohol or triol.

Among these polymers, particularly preferable ones are polyurethanes using polytetramethylene glycol as a polyol, or poly ε-caprolactone or polybutylene adipate. When polyethylene glycol is used as the polyol, it is used for a special purpose because its hydrophilicity is improved. As the organic diisocyanate, p, p'-diphenylmethane diisocyanate is preferable. Further, as the chain extender, p, p'-bishydroxyethoxybenzene and 1,4-butanediol are preferable. The polyurethane elastic body is synthesized from a polyol, an organic diisocyanate and a chain extender as described above, and it is preferably used in the present invention because the polyol component is 65% by weight or more of the whole, 70% by weight or more is preferable. When the content of the polyol component is small, the elongation and elongation recovery of the obtained fiber sheet are low.

Polyethylene terephthalate, polybutylene terephthalate, nylon 6, nylon 66, polypropylene, EVOH and the main components thereof are used for the thermoplastic fiber-forming inelastic polymer (b) and the inelastic fiber (B). Although a copolymer and a mixture are mentioned, EVOH is especially preferable in terms of hydrophilicity.

The composite filament (D) which achieves the fiber sheet of the present invention comprises a thermoplastic fiber-forming polyurethane elastic body (a) and a thermoplastic fiber-forming non-elastic polymer (b).
In order to be separable, it is necessary for all of them to be joined with a cross-sectional shape exposed on the outer peripheral surface of the fiber, as shown in FIGS. In order that the composite filaments (D) are laminated and the joint points thereof are fused to each other by the polyurethane elastic body (a) itself, the polyurethane elastic body (a) is 30% or more in the composite filament (D). It is advantageous to occupy a surface area ratio, the inelastic polymer (b) is easy to be divided, and in order to produce a large number of thin inelastic fibers (B), an irregular cross-sectional shape such as an ellipse is used. More preferably it occupies a surface area ratio of 75%.

The average diameter of the composite filament (D) is usually 10 to 70 μm or less, preferably 15 to 50 μm. When the fiber diameter becomes large, the obtained fiber sheet becomes coarse and rigid, while when it is less than 10 μm, the spinning temperature becomes high, so that the discharged composite filaments are easily bundled. The polyurethane elastic filaments (A) after division usually have a fineness of 50 denier or less, and in the case of aiming at a high stress stretchable napped sheet, one filament is set to 20 to 50 denier for the purpose of low stress. If this is done, the yarn is set to 1 to 5 denier by splitting it into 2-3 yarns. On the other hand, the non-elastic fiber (B) after division usually has a fineness of 30 denier or less, and the number of divisions is increased in order to obtain a high density nonwoven fabric. The dryness can be further improved. The diameters of the composite filaments (D) constituting the fiber sheet are not the same. For example, when observing an average diameter of 20 μm with an electron microscope, it is 10 to 25.
It is distributed in the range of μm. In addition, the basis weight of the fiber sheet is 5
The component of the polyurethane elastic filament (A) preferably accounts for 20 to 60% by weight in the range of 0 to 300 g / m ² .

In the fiber sheet used in the present invention, the thermoplastic fiber-forming polyurethane elastic body (a) and the thermoplastic fiber-forming non-elastic polymer (b) are respectively melted and weighed, and then joined at the spinneret portion, for example, The melt blow spinning device described in JP-A-60-99057 or JP-A-2-289107 is used to discharge the powder from a spinning nozzle and to thin the composite filament by a heated gas flow jetted from both sides of the nozzle. The thinned composite filaments are separated from the gas stream on a moving conveyor net or other collecting device and are laminated on the net without being substantially focused. The contact points of the polyurethane elastic body (a) are joined by fusion bonding of the polyurethane elastic body itself in a state in which the laminated composite filaments are laminated by the heat which they have.
After laminating on the collection device, before or after cooling and solidifying, heating and pressurization may be performed using a roller or the like to join them. In order to strengthen the bonding of the contact points between the composite filaments, the distance from the spinning nozzle to the position where the filaments are stacked on the collecting device should not be too long, and is at most 1 m, preferably 50 cm or less. A gas flow guide passage may be provided between the nozzle and the collector, but it is not necessary.

In the present invention, a thermoplastic polyurethane elastic body is used. Further, if a polyisocyanate compound is added to a melted polyurethane elastic body and kneaded and then discharged from a spinning nozzle, heat resistance and solvent solubility resistance are improved. An improved fiber sheet is obtained.

In the fibrous sheet used in the present invention, it is preferable that the above-mentioned composite filaments are opened and laminated without being focused substantially in the longitudinal direction of the fiber. If the single yarn is fused without being opened, it is not possible to obtain the texture of the fiber cloth because the flexibility of the fiber sheet is reduced and the division of the composite filament is significantly impaired.

Next, as a method of dividing the composite filaments constituting the fiber sheet, a polyurethane elastic body (a) is used.
And the non-elastic polymer (b) are combined. That is, in the case of a combination having poor adhesiveness such as polyurethane / polyethylene terephthalate or polyurethane / polypropylene, the fiber sheet is stretched to divide the non-elastic fiber (B) at the same time as stretching, so that the polyurethane / EV can be divided.
Mechanical combinations such as expansion, contraction, bending, twisting, friction, etc. for combinations with poor splittability such as OH and polyurethane / nylon 6,
By a chemical method in which the difference in swelling / contractibility is utilized by immersing in benzyl alcohol or phenol, or a combination of these methods.

As a method for stretching the fiber sheet to stretch the non-elastic fiber (B) of the composite filament, if necessary, the fiber sheet is heated by contact with a heating fluid or by a heating roller, and the non-elastic fiber It is possible to apply a known method in which the stretched non-elastic fiber (B) is stretched in at least one direction to develop the fiber performance. If necessary, the biaxial stretching method used for the film can be used.

The draw ratio depends on the conditions and applications of melt blow spinning, but the draw ratio (Rmax) shows the maximum stress (strength) in the tensile test for measuring the breaking strength and elongation.
Is usually set to about 70 to 120% (however, the elongation limit of the polyurethane elastic filament (A) is not exceeded). For example, polyethylene terephthalate is 3 to 7
Double, nylon 6 2.5-6 times, polypropylene 4-4
It is about 12 times, but its upper limit is about 6 times because it is combined with polyurethane elastic filaments.

In the fibrous sheet, the non-elastic fibers (B) are laminated by splitting and stretching at a length of at least twice the length of the polyurethane elastic filaments (A) at the joining points without tension. The non-elastic fiber (B) exists in the form of slack, loop or fluff. Draw ratio is Rmax of 90
If it is set to a large value of at least%, a part of the inelastic fiber (B) is cut to obtain a fiber sheet having a lot of fluffy naps. If it is further 150% or more, the strength of the fiber sheet may be lowered and the holding power of the fluff may be lowered.

The fiber sheet of the present invention may further include a step of further injecting a fluid such as air or water so that the non-elastic fiber (B) is unevenly distributed on one side. It is more effective if the fibrous sheet is stretched by, for example, 1.5 to 2.0 times, so that the texture of the woven fabric can be further imparted.

The fibrous sheet used in the present invention has a breaking elongation of usually 300% or more, preferably 500 to 700%, and the breaking strength thereof varies depending on the thickness of the fibrous sheet, but is 0.5.
It is at least kg / cm, preferably at least 1.0 kg / cm. Also, the recovery rate at 100% elongation is usually 80% or more,
It is preferably a fiber sheet having a stretch recovery of 85% or more. Another feature of the fiber sheet is that it has extremely excellent air permeability and a soft texture.

For the fixation of silk proteins, the crystallinity is modified to 1/2 or less of that of natural silk, and the volume average particle diameter is 5 μm.
A water or organic solvent dispersion liquid of the following fine powder modified silk powder or a processing liquid obtained by adding a synthetic resin emulsion or a water-soluble polymer to the dispersion liquid is applied to the above-mentioned non-woven fabric and subjected to dry heat or wet heat treatment. The method is preferred (Japanese Patent Laid-Open No.
In addition, known methods such as treatment with an aqueous silk fibroin solution and a method of chemically fixing silk protein can be applied. The amount of silk protein adhered is usually 0.
It is from 05 to 5.0% by weight. Below 0.05% by weight,
Insufficient water absorption and quick-drying performance, but 10% by weight
If it exceeds, the flexibility and feel of the non-woven fabric deteriorate.

In the present invention, a urethane resin emulsion or a mixed emulsion containing 50% by weight or more of the urethane resin emulsion is preferable for maintaining the stretchability of the nonwoven fabric. The urethane resin emulsion is synthesized by a known method such as phase inversion emulsification, a method using a blocked isocyanate, a method by an interfacial polycondensation reaction, and the like. The blending ratio (weight) of fine powder modified silk powder component / synthetic resin emulsion is
It is usually 50/50 to 80/20.

The silk protein used in the method of the present invention includes eyebrows, raw silk, eyebrows scraps, raw silk scraps, screws, fried cotton, silk cloth scraps, burettes, etc. in the presence of an activator, if necessary, in warm water. Of silk fibroin by heat treatment or salting-out of refined silk obtained by removing sericin in warm water in the presence of enzyme and dried, regenerated silk coarse powder produced by an ordinary method from silk fibroin aqueous solution, and further treated with salting out. Examples include those whose crystal structure has been converted and whose crystallization has been promoted, and embrittled silk coarse powder produced by treating silk fibers with an acid or an alkali. Further, the finely powdered modified silk powder having a volume average particle diameter of 5 μm or less is wet-milled (preferably, the regenerated silk coarse powder or the embrittled silk coarse powder with water or an organic solvent as a dispersion medium by a conventional method). Ball mill) to manufacture.

In the present invention, the method of applying water or an organic solvent dispersion liquid or a synthetic resin emulsion of silk protein such as fine powder modified silk powder to the cloth is not particularly limited, but the pad method and the spray method are used. , And the roller method can be applied. The cloth to which the silk protein is applied is dried, and further subjected to dry heat or wet heat treatment to form a strong film. The dry heat treatment is performed at 120 ° C. or higher, preferably 150 ° C. or higher, and the wet heat treatment is performed at 90 ° C. or higher, preferably 110 ° C. or higher.
Then, you may wash with warm water as needed. By washing, a proper rubbing action is added, the adhesion between the fibers is relaxed, and the soft finish is improved.

[0026]

Industrial Applicability The nonwoven fabric of the present invention is rich in elastic stretch recovery, has a bulky feel, and is also excellent in water absorption and quick drying. Further, according to the production method of the present invention, a nonwoven fabric having such characteristics can be produced industrially easily and inexpensively. The nonwoven fabric of the present invention is a hair band, a supporter,
It is useful as a material for sportswear, wound protection sheets, elastic tape for diapers, etc.

The nonwoven fabric of the present invention is evaluated by the following physical property values. Breaking strength and elongation A sample having a width of 2 cm is stretched at a gripping interval of 5 cm and a pulling speed of 20 cm / min according to JIS L-1096, and the strength and the elongation per 1 cm width at break are measured. 100% elongation recovery rate Grasp a sample with a width of 2 cm, spacing 5 cm, pulling speed 10 cm
/ Min to 100% elongation and immediately recovers to original length at the same speed. The residual elongation rate L (%) is calculated from the recorded load-elongation curve, and the 100% elongation recovery rate is calculated by the following formula. 100% elongation recovery rate (%) = 100-L water retention rate The scouring air-dried fiber cloth was immersed in room temperature water for 60 minutes and dehydrated for 3 minutes in a dehydrator of a domestic washing machine to express the weight increase as a percentage. It is a thing. Water absorption The "high water absorption", which indicates the diffusibility of water, was measured according to the Bayrex method (however, the measured value after 5 minutes is shown). Quick-drying The dehydrated cloth used to measure the water retention rate was RH at 22 ° C and 65%.
Weight loss after being hung in the atmosphere for 6 minutes, expressed as a percentage. The larger the reduction rate is, the better the quick drying property is.

[0028]

【Example】

Comparative Example 1 Dehydrated polybutylene adipate 116 having a hydroxyl value of 56
0 part (all the following parts mean all parts by weight) and 179 parts of 1,4 butanediol were charged into a kneader with a jacket, sufficiently dissolved while stirring, and then kept at a temperature of 85 ° C. , P'-diphenylmethane diisocyanate was added and reacted. If you continue stirring, about 3
In 0 minutes, a powdery polyurethane was obtained, which was molded into pellets by an extruder and was placed in dimethylformamide at 25 ° C.
Relative viscosity of concentration 1g / 100cc measured by
The thermoplastic polyurethane elastic body of was obtained.

Using the polyurethane elastic body pellets thus obtained as a raw material, a melt blow spinning apparatus having slits for jetting heated gas on both sides of a spinning nozzle having a diameter of 0.6 mm arranged in a row is used and the melting temperature is 245. Air discharged from the nozzle at ℃ and heated to 200 ℃ is 1.8kg / cm
^It was sprayed from the slit at a pressure of ² to make it thinner. The thinned filaments were collected on a conveyer consisting of a 30 mesh wire mesh placed 25 cm below the nozzle, and were caught by a roller with a basis weight of 12 g / m ² , 100% elongation recovery rate 91.
% Non-woven fabric was obtained. In this non-woven fabric, monofilaments of polyurethane elastic fibers having an average diameter of 20 μm were opened and laminated, and the entanglement points between the filaments were joined to each other by fusion bonding.

Comparative Example 2 Using silk spun waste as a raw material for silk fibroin,
00 gr. Marcel soap 30 gr. , Water 3000g
r. Stirring and scouring at 95-98 ° C. for 3 hours,
The residual glue was reduced to 0.1% or less, washed with water, and dried with hot air at 80 ° C. Calcium chloride (CaCl ₂ · 2H ₂ O)
100 gr. To 100 gr. And a 38 wt% calcium chloride aqueous solution 200 gr. Was prepared and heated to 110 ° C. To this, 40 gr. Was added with stirring using a kneader for 5 minutes, and further stirred for 30 minutes to completely dissolve it. Next, inner diameter 200μ, film thickness 2
20 μm regenerated cellulose hollow fiber with a length of 0 μm and a length of 500 mm
Using a hollow fiber type dialysis device in which 00 bundles were bundled and the both ends were converged and fixed (sealed) without blocking the hollow holes, the dissolution solution was introduced at a rate of 0.1 l / hour to deionize water. It dialyzed using and obtained the fibroin aqueous solution. The fibroin concentration of the aqueous fibroin solution was 6.5.
%, Residual calcium chloride was 0.001%. The obtained fibroin aqueous solution 500 gr. 100 / se
The mixture was stirred at high speed with a stirring blade so as to give a shear deformation rate of c or more. When stirring is continued for 2 to 3 hours, silk fibroin particles are precipitated next, and finally the whole aggregates as small aggregates of gel particles (15% crystallinity, 58% β structure ratio), which separates from water to form silk fibroin. Regenerate with a yield of almost 100%. The stirring was continued at high speed, and then a concentrated 30% ammonium sulfate aqueous solution was added to about 40 gr. As a result of mixing and further stirring for 1 hour and subjecting the silk fibroin crystals to α → β conversion, the gel body was crushed into small particles. Then, the gel body was filtered off, washed with water and dried at 105 ° C. for 2 hours, resulting in 32 gr. A regenerated silk crushed product was obtained (crystallinity 49%, β structure ratio 100%). The coarse powder 30 gr. Of water or organic solvent 270 gr. And were wet-milled at room temperature for 24 hours with a 1-liter hard porcelain ball mill. A ball made of hard porcelain having a diameter of 3 mm was mixed in an amount of 500 ml. The aqueous dispersion of finely powdered modified silk powder obtained by pulverization was a white emulsion and had a very smooth feel. As a result of measuring this with a centrifugal sedimentation type particle size distribution measuring device (Shimadzu SA-CP3 type), the particle size distribution is 0.33 to 4.68μ,
The average particle size was 2.13μ. This one is this one
The 0% dispersion was placed in a graduated cylinder and allowed to stand for 1 week.
The separation of the water layer and the powder layer was not observed at all, and the dispersion state was very stable.

10% of the above fine powder modified silk powder
30 parts of water dispersion liquid, Bondic 1610 (solid content 40, made by Dainippon Ink and Chemicals, Inc. as urethane resin emulsion
%) 2 parts of water was dispersed in water to prepare a total amount of 100 parts, and the polyurethane non-woven fabric of Comparative Example 1 was immersed in the solution, squeezed to a pick-up rate of 80%, pre-dried at 120 ° C. and HT steamer at 110 ° C. , Steam amount 0.5kg / cm
^The treatment was performed at ² for 10 minutes.

Comparative Example 3 The thermoplastic polyurethane elastic body of Comparative Example 1 was heated to 245 ° C.
Polyethylene terephthalate (easily dyed polyester) obtained by copolymerizing 5% by weight of polyethylene glycol having a molecular weight of 600 was melted by heating at 285 ° C. and bonded to a spinning nozzle at a weight ratio of 1: 1 as shown in FIG. Then, in the same manner as in Comparative Example 1 below, a fiber sheet composed of composite filaments having an average diameter of 28 μm was obtained. This fiber sheet had a basis weight of 120 g / m ² , and the composite filaments were opened and laminated into single yarns, and the entanglement points between the composite filaments were such that the polyurethane elastic material components were fused and bonded to each other.

Next, the fiber sheet is stretched 3.0 times in a hot water of 80 ° C. by a rotating roller and is sandwiched between a stainless steel plate which moves up and down twice per second to repeatedly expand and contract (3.0 ˜4.0 times elongation), the composite filaments constituting the fiber sheet were split. The polyurethane elastic filaments produced by splitting have a fineness with an average distribution of 4 denier and the split and stretched easy dye polyester fibers have an average of 1.6 denier, which makes the easy dye polyester fibers sagging or looping. It was stacked.

Example 1 A nonwoven fabric was produced by fixing silk protein in the same manner as in Comparative Example 2 with the fiber sheet stretched 1.5 times. Then, both ends of a section having a width of 7 cm and a length of 50 cm were sewn together and folded back twice to produce a hair band.

Example 2 A non-woven fabric and a hair band were produced in the same manner as in Example 1 except that the weight ratio of the composite filament was 1: 1 and the average diameter was changed to the composite shape as shown in FIG.

Example 3 Each of the above non-woven fabrics was cut into a length of 50 cm and a width of 10 cm, both ends were sewn and folded back in three layers to prepare a hair band. The hair band made from the nonwoven fabric of the present invention was excellent in sweat removal during tennis play, as compared with the comparative example.

[0037]

[Table 1]

[Brief description of drawings]

FIG. 1 shows an example of a cross-sectional shape of a composite filament suitable for the present invention.

[Explanation of symbols]

 A Polyurethane elastic filament component B Inelastic fiber component

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Claims (2)

[Claims] 1. A non-woven fabric comprising a fibrous sheet in which a polyurethane filament (A) and an inelastic fiber (B) are laminated, and a silk protein is fixed to the non-woven fabric, wherein the joining point of the polyurethane filament (A) is polyurethane. The filaments (A) themselves are fused and the non-elastic fibers (B) are laminated in a length of at least twice the length of the polyurethane filaments (A) in the unstressed state. Non-woven fabric characterized by being 2. The non-woven fabric according to claim 1, wherein the non-elastic fiber (B) has a single yarn fineness of 1.0 denier or less.