JP2000073268A - Conjugated nonwoven fabric and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spun-lace nonwoven fabric having improved form stability and dimensional stability. SOLUTION: This conjugated nonwoven fabric is composed of the non-woven web that comprises extremely fine-divided fibers with a filament fineness of <=0.5 denier developed by dividing a division type bicomponent conjugated short-cut fibers made of a low-melting polymer and/or a high-melting polymer and another short-cut fiber web including a fiber-forming polymer that does not melt at the temperature at which low-melting polymer melts or softens. These webs are laminated, these fibers are entangled three-dimensionally to each other and the low-melting polymer is melted or softened to fuse the crossing points of the fibers constituting the laminated web.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spunlace nonwoven fabric and a method for producing the same.

[0002]

2. Description of the Related Art Spunlace nonwoven fabrics in which constituent fibers are three-dimensionally entangled by the action of a high-pressure liquid flow are used in various applications because of their large inter-fiber voids and high flexibility. . As the material of the constituent fibers, natural fibers, synthetic fibers, and the like are appropriately selected and used according to various uses. However, since spunlace nonwoven fabric is made into a nonwoven fabric only by entanglement of fibers,
It is inferior in shape retention and dimensional stability as compared with nonwoven fabric or the like in which fibers are bonded by thermal bonding.

[0003] In order to improve the shape retention and dimensional stability of the spunlaced nonwoven fabric, the pressure of the high-pressure liquid stream is increased,
In addition, it is conceivable to increase entanglement between fibers by increasing the number of treatments. However, in this method, the entanglement of the fibers becomes too dense, the bulkiness of the nonwoven fabric is reduced,
In addition, there is a problem that the mechanical properties of the nonwoven fabric obtained by damaging the constituent fibers due to excessive liquid flow treatment are inferior.

[0004]

SUMMARY OF THE INVENTION The object of the present invention is to solve the above problems and to provide a spunlaced nonwoven fabric having good shape stability and dimensional stability.

[0005]

That is, the present invention provides the following (1) to (4). (1) The fiber-forming low melting point polymer is incompatible with the low melting point polymer and has a melting point of 30 to 180 from the melting point of the low melting point polymer.
And a low-melting polymer having a single-fiber fineness of 0.5 denier or less expressed by split splitting of a splittable two-component composite short fiber comprising a fiber-forming high-melting polymer having a high melting point and / or
Or a nonwoven web composed of ultrafine fibers made of the high melting point polymer, and a short fiber web made of a fiber forming polymer that does not melt at a temperature at which the low melting point polymer melts or softens, A composite nonwoven fabric, wherein constituent fibers are entangled three-dimensionally, and the low melting point polymer is melted or softened to thermally fuse the intersections of the constituent fibers.

(2) a fiber-forming low-melting polymer, a fiber-forming high-melting polymer incompatible with the low-melting polymer and having a melting point 30 to 180 ° C. higher than the melting point of the low-melting polymer; The single-filament fineness expressed by the split splitting of the splittable bicomponent conjugate short fibers consisting of: is composed of the low-melting polymer having a denier of 0.5 denier or less and / or the ultrafine splitting fiber composed of the high-melting polymer. A nonwoven web and a short fiber web made of a fiber-forming polymer that does not melt at a temperature at which the low melting point polymer melts or softens are laminated, and the constituent fibers are three-dimensionally entangled with each other, and A composite nonwoven fabric having a partial thermocompression bonding part partially thermocompression bonded with a low melting polymer.

(3) a fiber-forming low-melting polymer, a fiber-forming high-melting polymer incompatible with the low-melting polymer and having a melting point 30 to 180 ° C. higher than the melting point of the low-melting polymer; A nonwoven web composed of splittable bicomponent conjugate short fibers consisting of: and a laminated web obtained by laminating a short fiber web consisting of a fiber-forming polymer that does not melt at a temperature at which the low-melting polymer melts or softens. Placed on a moving porous support plate and subjected to high-pressure liquid flow treatment to split the split type bicomponent conjugate short fibers into split fibers, and the single-filament fineness is 0.5 denier or less. After the combined fibers and / or the ultrafine splitting fibers made of the high melting point polymer are developed, the constituent fibers are three-dimensionally entangled and integrated, and then heat-treated to melt or soften the low melting point polymer. To bond the intersections of the constituent fibers Method for producing a composite nonwoven fabric which is characterized and.

(4) a fiber-forming low-melting polymer, a fiber-forming high-melting polymer incompatible with the low-melting polymer and having a melting point 30 to 180 ° C. higher than the melting point of the low-melting polymer; A nonwoven web composed of splittable bicomponent conjugate short fibers consisting of: and a laminated web obtained by laminating a short fiber web consisting of a fiber-forming polymer that does not melt at a temperature at which the low-melting polymer melts or softens. Placed on a moving porous support plate and subjected to high-pressure liquid flow treatment to split the split type bicomponent conjugate short fibers into split fibers, and the single-filament fineness is 0.5 denier or less. After expressing the ultrafine splitting fibers made of the combined and / or high-melting polymer, the constituent fibers are three-dimensionally entangled and integrated, and then subjected to a partial thermocompression treatment to obtain the low-melting polymer. Is melted or softened to form a partially thermocompression bonded part. Method for producing a composite nonwoven fabric which is characterized in that.

[0009]

Next, an embodiment of the present invention will be described in detail. The splittable bicomponent conjugate short fiber used in the present invention comprises a fiber-forming low-melting polymer and a fiber-forming high-melting polymer that is incompatible with the low-melting polymer. The reason that the low-melting polymer and the high-melting polymer are incompatible with each other is to make it easy to split when a short conjugate fiber is impacted.

[0010] The melting point of the fiber-forming high melting point polymer of the splittable bicomponent conjugate short fibers must be 30 to 180 ° C higher than the melting point of the fiber-forming low melting point polymer. If the difference between the two melting points is less than 30 ° C., during the heat treatment, not only the low-melting polymer but also the high-melting polymer will be melted, so that the fiber morphology is impaired and the entire nonwoven fabric surface becomes film-like, For example, it is not preferable for use in contact with the human body because the soft feeling is poor. On the other hand, if the difference in melting point exceeds 180 ° C., the low-melting-point polymer is liable to undergo thermal deterioration when melt-spinning both polymers, which makes it difficult to practically produce short conjugate fibers.

Specific examples of splittable bicomponent conjugate short fibers include those having a cross section as shown in FIGS. In these, both components of the fiber-forming low-melting polymer and the fiber-forming high-melting polymer are both exposed on the surface of the fiber, and in the cross section of the fiber, one component is split by the other component. It is divided into possible forms.

The ratio of the fiber-forming high-melting polymer to the fiber-forming low-melting polymer of the splittable two-component conjugate short fibers is not particularly limited, and the number of the composites to be finely divided is taken into consideration. What is necessary is just to select suitably according to the cross-sectional shape of a fiber.
It is preferable to be in the range of 5/65 to 65/35 (weight ratio).

The single yarn fineness of the split type bicomponent conjugate short fiber is as follows:
Preferably it is 1 to 12 denier. Single yarn fineness is 1
When it is less than denier, the discharge amount per single hole of the spinneret during melt spinning is reduced, and the production amount tends to decrease, and in order to improve the production amount, the number of holes in the spinneret is increased. Then, the spinning process becomes unstable. On the other hand, if the single yarn fineness exceeds 12 denier, it tends to be difficult to take off due to insufficient cooling of the melt-spun yarn, and to promote the cooling of the yarn, the number of holes in the spinneret is reduced. Productivity decreases.

The splittable bicomponent conjugate short fibers are split at the boundary between the low-melting polymer and the high-melting polymer by splitting using a high-pressure liquid stream, and the low-melting polymer and / or the high-melting polymer are separated. The ultrafine split short fibers composed of a polymer partially appear. In the present invention, the single-fiber fineness of the ultrafine split short fibers expressed at least is 0.5 denier or less, more preferably 0.05 to 0.5 denier, even more preferably 0.1 to 0.5 denier. is there. If the single yarn fineness is less than 0.05 denier, spinning becomes practically difficult, and it is difficult to obtain a splittable bicomponent conjugate short fiber inexpensively and reasonably. In addition, there is a tendency that it is difficult to perform split splitting sufficiently. On the other hand, if it exceeds 0.5 denier, the resulting nonwoven fabric has a tendency that the constituent fibers targeted by the present invention are densely entangled, a nonwoven fabric having a smooth surface cannot be obtained, and the nonwoven fabric tends to have a coarse hard feeling. is there.

In the present invention, examples of the combination of the low-melting polymer and the high-melting polymer constituting the splittable bicomponent conjugate short fiber include polyolefin / polyamide, polyolefin / polyester, polyamide / polyester, etc. These are typical examples, and other various combinations are also arbitrarily adopted.

Examples of the polyester include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, and naphthalene-2,6-dicarboxylic acid, aliphatic dicarboxylic acids such as adipic acid and sebacic acid, and esters thereof. And a homopolyester polymer or copolymer containing a diol compound such as ethylene glycol, diethylene glycol, 1,4-butanediol, neopentyl glycol, cyclohexane-1,4-dimethanol as an ester component. In addition, these polyester-based polymers include p-hydroxybenzoic acid, 5-hydroxybenzoic acid,
Sodium sulfoisophthalic acid, polyalkylene glycol, pentaerythritol, bisphenol A or the like may be added or copolymerized.

As the polyolefin, C 2-18
Aliphatic α-monoolefins such as ethylene, propylene, 1-butene, 1-pentene, 3-methylbutene
Examples thereof include polyolefin-based polymers composed of 1,1-hexene, 1-octene, and 1-octadecene. These aliphatic α-monoolefins can be used in many ethylenically unsaturated monomers such as butadiene, isopropylene, pentadiene-
It may be a polyolefin polymer in which similar ethylenically unsaturated monomers such as 1,3, styrene and α-methylstyrene are copolymerized. In the case of a polyethylene polymer, propylene, 1-butene,
1-octene, 1-hexane, or a similar higher α-olefin may be copolymerized in an amount of 10% by weight or less. In the case of polypropylene, ethylene or a similar higher α-olefin is used with respect to polypropylene. May be copolymerized, but the copolymerization rate is 10% by weight.
If the temperature exceeds the above range, the melting point of the copolymer will decrease. Therefore, it is not preferable to use short fibers made of this copolymer at high temperatures.

Examples of polyamides include polyimino-1-oxotetramethylene (nylon 4), polytetramethylene adipamide (nylon 46), polycapramid (nylon 6), and polyhexamethylene adibamide (nylon 6).
6) Polyundecanamide (nylon 11), polyurolactamide (nylon 12), polymethaxylene adibamide, polyparaxylylene decanamide, polybiscyclohexylmethanedecanamide, or a monomer thereof as a structural unit Polyamide-based copolymers. In particular, in the case of polytetramethylene adipamide (nylon 46), polytetramethylene adipamide (nylon 46)
A copolymer of polytetramethylene adivamide obtained by copolymerizing a polyamide component such as polycapramid, polyhexamethylene adibamide, polyundecamethylene terephthalamide and the like in an amount of 30 mol% or less may be used. When the copolymerization ratio of the polyamide component exceeds 30 mol%, the melting point of the copolymer decreases. Therefore, when short fibers made of such a copolymer are used, use at a high temperature is not preferable.

Examples of other fiber-forming polymers include:
For example, a vinyl polymer is used, and specifically, polyvinyl alcohol, polyvinyl acetate, polyacrylate, ethylene vinyl acetate copolymer, polyvinyl chloride, polyvinylidene chloride, or a copolymer thereof is used. . Further, a polyphenylene-based polymer or a copolymer thereof can also be used.

The fiber-forming low-melting polymer and the fiber-forming high-melting polymer include matting agents, pigments, flame retardants, deodorants, antistatics, as long as the effects of the present invention are not impaired. An optional additive such as an agent or an ultraviolet absorber may be added.

The splittable bicomponent conjugate short fibers are generally produced by the following method. That is, after spinning by a conventionally known melt spinning method, using a conventionally known cooling device such as horizontal spraying or annular spraying, cooling by spraying air, applying an oil agent, and forming an undrawn yarn through a take-off roller. Wind it up on a winder. Pickup roller speed is 500m / min ~ 200
0 m / min. A plurality of wound undrawn yarns are drawn and aligned, and drawn between a group of rollers having different peripheral speeds by a known drawing machine. Next, the drawn tow is crimped by a press-type crimping device, and then cut into a predetermined fiber length to obtain short fibers. The stretch tow may be subjected to heat setting at a temperature equal to or lower than the melting point of the material depending on the required use.

Next, a fiber-forming polymer which does not melt at a temperature at which the low-melting polymer laminated on the non-woven web made of ultrafine split fibers made of the low-melting polymer and / or the high-melting polymer melts or softens. The short fiber web made of the united material will be described. The constituent fibers of the short fiber web may be fibers made of a fiber-forming polymer that does not melt at a temperature at which the low-melting polymer constituting the ultrafine split fibers melts or softens, and is formed of a single polymer , A core-sheath type, a composite form composed of a plurality of polymers such as side-by-side type, and the like,
Either can be used. Further, the web may be composed of one type of short fiber or a web in which a plurality of types of fibers are mixed. As the fiber-forming polymer used,
What is necessary is just to select suitably from the polymer which comprises the split type bicomponent composite short fiber mentioned above.

The basis weight of the nonwoven fabric of the present invention is not particularly limited and may be appropriately selected depending on the use.
About 00 g / m ² is preferable. If the basis weight is less than 20 g / m ² , the nonwoven fabric becomes poor in formation and the morphological stability and dimensional stability of the nonwoven fabric tend to be poor. On the other hand, if the basis weight exceeds 200 g / m ² , the processing energy of the high-pressure liquid flow treatment for three-dimensionally entangled the constituent fibers becomes large, which is not economically preferable. Also,
In some cases, in the inner layer of the nonwoven fabric, sufficient entanglement between the fibers and split splitting of the splittable bicomponent conjugate short fibers are not sufficiently performed, and the nonwoven fabric tends to have low mechanical strength. However, the nonwoven fabric of the present invention also includes those in which split bicomponent conjugate short fibers are not split sufficiently and partially remain, and those in which the fibers are not sufficiently entangled in the inner layer of the nonwoven fabric. Needless to say.

(Non-woven web composed of ultrafine split fibers) /
The lamination ratio of the (nonwoven web composed of a fiber-forming polymer that does not melt at a temperature at which the low-melting polymer melts or softens) is preferably 80/20 to 50/50 (% by weight). 50% by weight of non-woven web made of extra fine split fiber
By doing so, the dimensional stability and abrasion resistance of the nonwoven fabric can be improved. On the other hand, if it exceeds 80% by weight,
The flexibility of the nonwoven fabric tends to be impaired.

Next, the method for producing the nonwoven fabric of the present invention will be described. A short fiber made of a fiber-forming polymer that does not melt at a temperature at which the low-melting polymer melts or softens, and a split-type bicomponent conjugate short fiber, each of which is carded by a carding machine to form a nonwoven web having a predetermined weight. create. As the degree of arrangement of the constituent fibers, the parallel web arranged in the traveling direction of the card machine, the web in which the parallel web is cross-laid and the arrangement of the fibers is changed from the machine direction to the horizontal direction, and the arrangement of the fibers by the random card machine are uniform. Not a random web, or a semi-random web that is arranged in a medium order by a semi-random card machine, etc.
What is necessary is just to select suitably according to a use etc.

Each of the obtained webs is laminated to form a laminated web, and the laminated web is mounted on a moving porous support plate.
1.5mm injection holes with an injection hole interval of 0.05-5mm
A fluid jetted at a high pressure from a plurality of orifice heads arranged in a row or a plurality of rows collide with a laminated web placed on a porous support member.

By performing the high-pressure liquid flow treatment, the splittable bicomponent conjugate short fibers are split and split by the impact of a high-pressure water stream, and the ultrafine split short fibers made of a low-melting polymer and / or a high-melting polymer are used. And the fibers are densely entangled with each other. On the other hand, the short fibers made of the fiber-forming polymer are also entangled with each other, and also at the laminating interface of the two nonwoven webs, the ultrafine split short fibers and the fibers made of the low melting polymer and / or the high melting polymer are also formed. Short fibers made of a forming polymer are entangled with each other to obtain a nonwoven fabric entangled and integrated as a whole.

Normal temperature water or hot water can be used as the fluid. When the fluid jet impinges on the laminated web, the orifice head provided with the jet holes is set at the same interval as the jet holes in a direction perpendicular to the traveling direction of the laminated web placed on the porous support member. It is good to make it oscillate at intervals and make high-pressure liquid jets collide uniformly.

The distance between the injection hole and the laminated web is 1 to 15
cm is preferred. If the distance is less than 1 cm, the movement of the fibers in the laminated web becomes intense, and the formation of the obtained nonwoven fabric tends to be disturbed. On the other hand, when this interval exceeds 15 cm, the impact force when the high-pressure liquid stream collides with the laminated web is reduced, and the entanglement between the constituent fibers and the splitting tend to be insufficient. As the material of the porous support member used at the time of the high-pressure liquid injection, any of metal, polyester, and other materials may be used as long as the material can pass the high-pressure liquid flow through the laminated web and the support member. May be. When a mesh-shaped porous support member is used, the range of the mesh may be about 25 to 200 mesh (25 to 200/25 mm), and may be appropriately selected according to the use of the nonwoven fabric.

In the high-pressure liquid flow treatment, it is preferable to perform a two-stage treatment of preliminary confounding and main confounding in which the water pressure is changed. First,
The laminated web is subjected to a liquid flow with a water pressure of less than 40 kg / cm ² G. By performing pre-entanglement with a liquid flow having a water pressure of less than 40 kg / cm ² G, a nonwoven fabric having no spots can be obtained without causing disturbance of the laminated web due to the accompanying air flow generated by the liquid flow injection. Further, it is preferable that the fluid is jetted with the short fiber web made of the fiber-forming polymer facing upward. By setting the short fiber web on the upper side, it is easy to obtain a nonwoven fabric without spots.

Following the preliminary confounding, the water pressure is 40 kg / cm ² G
The confounding process is performed by the above-described liquid flow injection. Water pressure 40k
By performing the entanglement treatment with a liquid flow of g / cm ² G or more, the short fibers constituting the pre-entangled laminated web are three-dimensionally entangled and integrated.

Further, the entangled non-woven fabric is further inverted and subjected to an entanglement treatment with a liquid flow having a water pressure of 40 kg / cm ² G or more, whereby a spun-lace non-woven fabric sufficiently entangled on both sides can be obtained.

Next, excess water of the obtained entangled non-woven fabric is removed by a known moisture removing device such as a mangle.
Further, a drying process is performed by a suction band type hot air circulation type dryer or the like. At this time, in order to prevent the quality and quality of the nonwoven fabric from deteriorating, a wet heat treatment may be used together or employed. Further, in the drying process, processing conditions such as a drying temperature and a time may be appropriately selected so that not only a simple removal of moisture but also a proper shrinkage may be allowed.

The nonwoven fabric obtained by the drying treatment is subsequently subjected to a partial thermocompression treatment or a heat treatment. By performing this treatment, the low melting point polymer is melted or softened, and the constituent fibers are adhered and fixed. Then, the entangled state of the nonwoven fabric is fixed and the elongation is low, so that the nonwoven fabric is excellent in form stability, dimensional stability, mechanical strength, and abrasion resistance and washing resistance while maintaining bulkiness.

In the partial thermocompression treatment, heat and pressure are applied to a predetermined portion to soften or melt the low melting point polymer at that portion to form a partial thermocompression portion. As means for the partial thermocompression bonding, for example, means using an ultrasonic welding device, means using a heat embossing device, and the like can be given. The hot embossing device is composed of a heated concavo-convex roll and a smooth concavo-convex roll, or a pair of concavo-convex rolls.When a nonwoven fabric is introduced between the rolls, the convex portion of the heated concavo-convex roll presses the nonwoven fabric. Then, heat and pressure are applied from the convex portions, and the low-melting polymer is softened or melted, so that the short fibers are thermocompression-bonded to each other.
Then, the constituent fibers are heat-fixed in the thermocompression bonding portion, and a nonwoven fabric having improved form stability and dimensional stability, and excellent in tensile strength and abrasion resistance is obtained.

The heating temperature of the concavo-convex roll is set to a temperature lower than the melting point or softening point of the low melting point polymer. If the heating temperature of the concavo-convex roll is equal to or higher than the melting point or the softening point, there is a possibility that softening or fusion may occur between short fibers even outside the portion pressed by the convex portion, and during processing, the nonwoven fabric is rolled. , And the operability is remarkably poor, and a nonwoven fabric may not be obtained. Preferably, the temperature is set to be 5 to 30 ° C. lower than the melting point. If the temperature is lower than the melting point (−30 ° C.), the thermocompression bonding is not sufficiently performed, depending on the level of the linear pressure between the rolls. The linear pressure between the rolls is preferably 10 to 100 kg / cm, although it depends on the set temperature of the uneven roll.

Since the tip surface of the convex portion of the concave-convex roll is a portion where the nonwoven fabric is pressed, the shape, area, arrangement density, and the like of the convex portion determine the form of the thermocompression bonding portion. The tip shape of the projection is
A dotted shape such as a round shape, an elliptical shape, a diamond shape, a triangular shape, a T shape, a well shape, and a rectangular shape, or a continuous shape such as a linear shape or a grid shape can be employed. In the case of a scattered point, the area of one projection is preferably about 0.1 to 1.0 mm ² . The arrangement density of the convex portions is preferably ⁴ to 80 / cm ² , and more preferably 10 to 80 / cm ^2.
Preferably 60 pieces / cm ^2, and even most preferably 10 to 40 pieces / cm ^2. The total area of the projecting portion tip surface with respect to the total surface area of the roll (the surface area in a state where the projecting portions are neglected) is 4 to 40% (corresponding to the total area of the partial thermocompression bonding portion with respect to the entire area of the nonwoven fabric). Is preferable, and 10
It is preferably about 20%.

As a method of performing heat treatment without applying a linear pressure,
A hot air circulation system in which heat fusion is performed with hot air of dry heat, and a wet heat system using heating steam can be used effectively.
Since the form to be subjected to the hot air treatment is in a state where the form as the fabric is stable, the treatment can be performed without the constituent fibers of the nonwoven fabric being scattered by the hot air. In the nonwoven fabric subjected to the heat treatment, only the low melting point polymer is thermally melted or softened in a state where the constituent fibers are three-dimensionally entangled, and the intersections of the constituent fibers are thermally bonded. By this heat bonding, a nonwoven fabric having good shape stability and dimensional stability and improved wear resistance can be obtained.

The temperature of the hot air is preferably a temperature slightly higher than the melting point of the low melting point polymer, that is, a temperature 5 to 30 ° C. higher than the melting point. If the temperature is lower than (melting point + 5 ° C.), the low melting point polymer does not sufficiently melt or soften, so that the constituent fibers are not sufficiently bonded and fixed, and the abrasion resistance and dimensional stability aimed at by the present invention are intended. It is difficult to obtain a nonwoven fabric having a good quality. On the other hand, if the temperature is higher than (melting point + 30 ° C.), the low-melting polymer softens and flows, and the whole nonwoven fabric becomes a film, which gives a poor feel and a rough and hard feel. Even polymers other than melt,
It is not preferable because of the possibility of softening.

The temperature of the heating steam in the wet heat method depends on the pressure in the heating steam apparatus, but may be set to a temperature higher than the melting point of the low melting point polymer by 20 ° C.

Incidentally, the drying treatment after the high-pressure liquid flow treatment and the heat treatment for applying a linear pressure for thermal fusion can also be performed simultaneously.

A cam made by Uenoyama Kiko Co., Ltd. for the purpose of imparting flexibility to the non-woven fabric obtained by performing the partial thermocompression treatment or the heat treatment as long as the effect of heat bonding is not impaired. A flexible processing machine using a fitting machine may be used.

In the composite nonwoven fabric of the present invention, the constituent fibers are fixed to each other by the heat treatment, so that the elongation at break is reduced and not only the form stability and dimensional stability are improved, but also
The washing resistance of the nonwoven fabric and the abrasion resistance of the surface can be improved. In the abrasion test using a Gakushin abrasion tester, a nonwoven fabric is deformed after 20 reciprocations, and is present on the surface after 30 reciprocations, in a fiber-only abrasion test using a Gakushin-type abrasion tester. Despite the loss of fibers,
The heat-sealed non-woven fabric has excellent abrasion resistance, in which not only no change in the morphology of the non-woven fabric is observed even in 100 reciprocal tests, but also no fibers present on the surface fall off.

[0044]

The present invention will be described below with reference to examples. The flexibility of performance of the nonwoven fabric in the present invention was measured by the method described above, and other physical properties were measured by the following methods.

(1) Melting point of polymer (° C.): Temperature at which the maximum value of the melting endothermic curve was measured at a heating rate of 20 ° C./min using a differential scanning calorimeter DSC-2 manufactured by Perkin Elmer. Was taken as the melting point (° C.).

(2) Relative viscosity of polyester polymer:
100 parts by weight of a mixed solvent of phenol and ethane tetrachloride
0.5 g of the sample was dissolved in milliliter, and the measurement was carried out by a conventional method at a temperature of 20 ° C.

(3) Melt index of polyethylene (g / 10 minutes, hereinafter referred to as MI): ASTM D
It was measured by the method described in 1238 (E).

(4) Melt flow rate of polypropylene (g / 10 minutes, hereinafter referred to as MFR): ASTM D
It was measured by the method described in 1238 (L).

(4) Weight of nonwoven fabric (g / m ² ): Five sample pieces having a sample width of 10 cm and a sample length of 10 cm were prepared, their weights were measured, and the average value was taken as the weight (g / m ² ). .

(5) Tensile strength of nonwoven fabric: sample width 5c
m, 10 specimens each having a sample length of 15 cm were prepared, and the maximum tensile strength of the specimens was determined using a Toyo Baldwin Tensilon UTM-4-1-100 at a gripping interval of 10 cm and a tensile speed of 10 cm / min. Each was measured individually, and the average value (g / 5 cm) was taken as the tensile strength of the nonwoven fabric. The measurement was performed in both the machine direction (hereinafter referred to as the MD direction) and the direction orthogonal to the machine direction (hereinafter referred to as the CD direction) of the nonwoven fabric.

(6) Abrasion resistance (grade) of nonwoven fabric: A reciprocating friction test was performed 100 times using a Gakushin type friction tester, and a five-step evaluation was performed by visual evaluation. A nonwoven fabric surface with no abrasion and no fluff is classified as Class 5, and a nonwoven fabric surface with severely worn and fluff is classified as Class 1, with a grade of 2 to 4
Grade and graded. In addition, the abrasion resistance of the surface of the composite nonwoven fabric on the ultrafine split short fiber web side was evaluated.

Example 1 As a short fiber web made of a fiber-forming polymer, a melting point of 2
Short fiber made of polyethylene terephthalate having a relative viscosity of 1.38 at 58 ° C. (product name 10 manufactured by Unitika Ltd.)
1, a single fiber fineness of 2 denier and a fiber length of 51 mm), and a nonwoven web having a basis weight of 15 g / m ² was prepared by a parallel card machine.

On the other hand, as the splittable bicomponent conjugate short fibers, polyethylene terephthalate having a melting point of 258 ° C. and a relative viscosity of 1.38, and polyethylene having a melting point of 128 ° C. and an MI of 20 g / 10 minutes were mixed at a mixing ratio of 1: 1. (Weight ratio)
Using a composite spinneret from which a composite fiber having a cross-sectional shape shown in FIG. 1 is obtained, polyethylene terephthalate is arranged so as to form four leaves, and polyethylene is arranged so as to form a core,
Melt spinning was performed at a single hole discharge rate of 0.74 g / min and a melting temperature of 285 ° C. After cooling the spun polymer stream, 1100m
/ Min to obtain a drawn undrawn yarn. The undrawn fiber bundle in which a plurality of the obtained undrawn yarns are combined is hot drawn (drawing ratio 3.2 times), and then led to a press crimper,
After applying a crimp of 15 piles / 25 mm and applying an oil agent for spinning, it is subjected to a drying treatment and cut to obtain a single yarn fineness of 2 denier,
A splittable bicomponent conjugate short fiber having a fiber length of 38 mm was obtained. Using a parallel card machine, a weight of 45 g /
you create a nonwoven web m ^2.

The above two types of nonwoven webs are laminated, and the basis weight is 60
g / m ² of laminated web was obtained. The obtained laminated web is
It is placed on a 70-mesh metal support member moving at 0 m / min, and the water pressure is 35 kg from the injection holes arranged in a line at an injection hole diameter of 0.1 mm and an injection interval of 0.6 mm from a position 50 mm above the laminated web. Pre-entanglement was carried out with water at room temperature / cm ² G. Subsequently, water pressure 70 kg / cm ² G
Was injected four times to perform a confounding treatment. Further, the laminated web was inverted, and a water pressure of 70 kg / cm ² G was jetted five times to perform a entanglement treatment, thereby obtaining a nonwoven fabric in which both sides were densely entangled. After removing excess moisture from the obtained nonwoven fabric by a mangle, a drying treatment was performed with a dryer at a temperature of 100 ° C.

Subsequently, a heat treatment using hot air of dry heat was performed using a hot air circulation type dryer manufactured by Kotobuki Kogyo Co., Ltd. at a treatment temperature of 135 ° C. for 30 seconds to obtain a nonwoven fabric of the present invention. On the extra fine split fiber side of the obtained nonwoven fabric, an extra fine split fiber made of polyethylene terephthalate and having a single yarn fineness of 0.25 denier and a 1.0 denier split fiber made of polyethylene were observed.

Example 2 The procedure of Example 1 was repeated except that the lamination ratio of the short fiber web composed of the fiber-forming polymer / the web composed of the split bicomponent conjugate short fibers was 35/65 (% by weight). A nonwoven fabric of Example 2 was obtained in the same manner as in Example 1.

Example 3 The procedure of Example 1 was repeated except that the lamination ratio of the short fiber web composed of the fiber-forming polymer / the web composed of the splittable bicomponent conjugate short fibers was changed to 50/50 (% by weight). A nonwoven fabric of Example 3 was obtained in the same manner as in Example 1.

Example 4 The procedure of Example 1 was repeated except that the lamination ratio of the short fiber web composed of the fiber-forming polymer / the web composed of the splittable bicomponent conjugate short fibers was 55/45 (% by weight). In the same manner as in Example 1, a nonwoven fabric of Example 4 was obtained.

Example 5 Example 5 was repeated except that the lamination ratio of the short fiber web composed of the fiber-forming polymer / the web composed of the splittable bicomponent conjugate short fibers was changed to 15/85 (% by weight). In the same manner as in Example 1, a nonwoven fabric of Example 5 was obtained.

Example 6 In Example 1, the water pressure of the high-pressure liquid stream after the pre-entanglement was set to 1
A nonwoven fabric of Example 6 was obtained in the same manner as in Example 1 except that the weight was changed to 00 kg / cm ² G.

Example 7 As a split type bicomponent conjugate short fiber, the fiber cross section is shown in FIG.
The composite ratio of the short fiber web composed of the fiber-forming polymer / the web composed of the split type bicomponent composite short fiber is set to 65/35 (using a composite fiber in which the polymers are alternately arranged in units of 12 radially as shown in FIG. Wt%), heat treatment temperature by dry heat is 1
A nonwoven fabric of Example 7 was obtained in the same manner as in Example 1 except that the temperature was changed to 65 ° C.

The split type bicomponent conjugate short fibers were prepared as follows. That is, the polyethylene terephthalate used in Example 1 had a melting point of 160 ° C. and an MFR of 65 g.
/ 10 min polypropylene, single hole discharge 1.08
g / min, and a melting temperature of 285 ° C., a drawn undrawn yarn was produced at a speed of 1100 m / min. An undrawn fiber bundle obtained by combining a plurality of the obtained undrawn yarns is thermally drawn (drawing ratio: 3.
1x), then led to the crimper, 14 peaks /
A crimp of 25 mm was applied, an oil agent for spinning was applied, dried, and cut to obtain a conjugate short fiber having a single yarn fineness of 3.0 denier and a fiber length of 38 mm.

Example 8 In Example 5, the water pressure after the pre-entanglement was changed to 100 kg / c.
A nonwoven fabric of Example 8 was obtained in the same manner as in Example 5, except that m ² G was used.

Example 9 A nonwoven fabric of Example 9 was obtained in the same manner as in Example 1 except that the heat treatment in Example 1 was replaced with the dry heat treatment, and an embossing device was used, and the temperature of the uneven roll was set to 120 ° C. .

Comparative Example 1 A nonwoven fabric of Comparative Example 1 was obtained in the same manner as in Example 1 except that no heat treatment was performed.

Comparative Example 2 A nonwoven fabric of Comparative Example 2 was obtained in the same manner as in Example 1, except that the heat treatment temperature was changed to 110 ° C.

Comparative Example 3 The heat treatment in Example 1 was performed in the same manner as in Example 1 except that the temperature of the uneven roll was set to 135 ° C. by using an embossing device instead of the dry heat treatment. The non-woven fabric was wound and no non-woven fabric could be obtained.

Table 1 shows the physical properties and the like of the obtained nonwoven fabrics of Examples 1 to 9 and Comparative Examples 1 and 2.

[0069]

[Table 1] As is clear from Table 1, the composite nonwoven fabrics of Examples 1 to 9 of the present invention have a good feel on the ultrafine split fiber web surface, have excellent abrasion resistance, form stability, and dimensional stability. Was good and also had mechanical strength.

On the other hand, the non-woven fabric of Comparative Example 1, which was not subjected to the heat treatment, was formed into a non-woven fabric only by the constituent fibers or by mechanical entanglement, so that it had high flexibility but was inferior in durability and abrasion resistance. It is unsuitable for applications that require properties.

In the nonwoven fabric of Comparative Example 2 in which the heat treatment temperature was 110 ° C., since the low melting point polymer was not sufficiently melted, the intersections of the constituent fibers were not adhered and fixed, and fluff was easily generated in the abrasion resistance test. However, because of its poor durability, it is not suitable for applications requiring wear resistance.

[0072]

The nonwoven fabric of the present invention is characterized in that the ultrafine splitting fiber composed of the low-melting-point polymer penetrated into the ultrafine splitting fiber web and into the short fiber web composed of the fiber-forming polymer during the entanglement treatment. The constituent fibers in a three-dimensionally entangled state are fixed or melted or softened by thermal compression bonding or heat treatment. Therefore, one side of the composite nonwoven fabric of the present invention is heat-bonded and fixed via a low-melting polymer in which the constituent fibers are fused or softened in a state where the ultrafine split short fibers that are constituent fibers are densely three-dimensionally entangled. This is an ultrafine split fiber web, in which the entangled state of the constituent fibers is fixed by thermal bonding, so that it is excellent in morphological stability, dimensional stability, mechanical strength, fuzziness and abrasion resistance. In the boundary layer between the two webs, the constituent fibers penetrate each other, and the short fibers made of the fiber-forming polymer, and the short fibers made of the fiber-forming polymer and the ultrafine split fibers are entangled with each other. Is heat-bonded via a softened or melted low-melting polymer, fixed and integrated, so its elongation is low,
Good shape stability and dimensional stability.

If the constituent fibers are not entangled with each other and are formed into a non-woven fabric only by thermal bonding, the non-woven fabric becomes extremely poor in mechanical strength depending on the amount of the low-melting polymer (thermal-adhesive component). If the polymer and the constituent polymer of the other constituent fibers are not compatible, the constituent fibers are likely to fall off from the bonded portion due to friction or the like, and the nonwoven fabric has poor durability.

According to the present invention, the composite nonwoven fabric has a low melting point weight since the constituent fibers are bonded and fixed by melting or softening of the low melting point polymer after the constituent fibers are entangled and integrated with each other. Regardless of the compatibility of the united polymer with the constituent polymer of the other constituent fibers, the constituent fibers are unlikely to fall off due to friction or the like.

Since the nonwoven fabric of the present invention has the above-described structure and effects, it can be effectively used in the fields of household goods, living materials, clothing, medical care and the like.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an example of a sectional shape of a splittable bicomponent conjugate short fiber used in the present invention.

FIG. 2 is a schematic view showing an example of a sectional shape of a splittable bicomponent conjugate short fiber used in the present invention.

FIG. 3 is a schematic view showing an example of a cross-sectional shape of a splittable bicomponent conjugate short fiber used in the present invention.

FIG. 4 is a schematic view showing an example of a sectional shape of a splittable bicomponent conjugate short fiber used in the present invention.

Claims (4)

[Claims] 1. A fiber-forming low-melting polymer which is incompatible with the low-melting polymer and has a melting point lower than the melting point of the low-melting polymer by 30%.
A low-melting polymer having a single fiber fineness of 0.5 denier or less expressed by split splitting of a splittable bicomponent conjugate short fiber comprising a fiber-forming high-melting polymer having a melting point higher by 180 ° C and / or A nonwoven web composed of ultrafine split fibers composed of the high melting polymer and a short fiber web composed of a fiber-forming polymer that does not melt at a temperature at which the low melting polymer melts or softens are laminated. A composite nonwoven fabric, wherein constituent fibers are entangled with each other three-dimensionally, and the low melting point polymer is melted or softened to thermally fuse the intersections of the constituent fibers. 2. A fiber-forming low-melting polymer which is incompatible with the low-melting polymer and has a melting point lower than the melting point of the low-melting polymer by 30%.
A low-melting polymer having a single fiber fineness of 0.5 denier or less expressed by split splitting of a splittable bicomponent conjugate short fiber comprising a fiber-forming high-melting polymer having a melting point higher by 180 ° C and / or A nonwoven web composed of ultrafine split fibers composed of the high melting polymer and a short fiber web composed of a fiber-forming polymer that does not melt at a temperature at which the low melting polymer melts or softens are laminated. A composite nonwoven fabric comprising a partially thermocompression-bonded portion in which constituent fibers are three-dimensionally entangled and partially thermocompression-bonded with the low-melting polymer. 3. A fiber-forming low-melting polymer which is incompatible with the low-melting polymer and has a melting point lower than the melting point of the low-melting polymer by 30%.
A nonwoven web composed of splittable bicomponent short fibers comprising a fiber-forming high-melting polymer having a high melting point of about 180 ° C. and a fiber formation that does not melt at a temperature at which the low-melting polymer melts or softens A laminated web obtained by laminating a short fiber web composed of a conductive polymer is placed on a moving porous support plate, subjected to a high-pressure liquid flow treatment, and divided into two-component split short fibers. The microfilament split fibers composed of the low-melting polymer and / or the high-melting polymer having a single-fiber fineness of 0.5 denier or less were expressed, and the constituent fibers were three-dimensionally entangled and integrated. Thereafter, a heat treatment is performed to melt or soften the low-melting polymer to bond the intersections of the constituent fibers, thereby producing a composite nonwoven fabric. 4. A fiber-forming low-melting polymer which is incompatible with the low-melting polymer and has a melting point lower than the melting point of the low-melting polymer by 30%.
A nonwoven web composed of splittable bicomponent short fibers comprising a fiber-forming high-melting polymer having a high melting point of about 180 ° C. and a fiber formation that does not melt at a temperature at which the low-melting polymer melts or softens A laminated web obtained by laminating a short fiber web composed of a conductive polymer is placed on a moving porous support plate, subjected to a high-pressure liquid flow treatment, and divided into two-component split short fibers. The microfilament split fibers composed of the low-melting polymer and / or the high-melting polymer having a single-fiber fineness of 0.5 denier or less were expressed, and the constituent fibers were three-dimensionally entangled and integrated. Thereafter, a method for producing a composite nonwoven fabric is characterized in that a partial thermocompression treatment is performed to melt or soften the low melting point polymer to form a partial thermocompression bonding portion.