JPH06128859A - Nonwoven fabric having three-layered structure and its production - Google Patents

Abstract

PURPOSE:To obtain a nonwoven fabric having three layer structure, excellent in bulkiness and heat retaining property, hardly causing fluffing and having good abrasion resistance. CONSTITUTION:This nonwoven fabric having three layer structure is composed of a conjugate type filament and arranged in order of a surface layer, an intermediate layer and a rear layer. The conjugate type filament is obtained by conjugating a thermoplastic polymer component A having low melting point with a thermoplastic polymer component B having high melting point. The component A and the component B are incompatible and at least component A is exposed on the surface of the conjugate type filament. In the surface layer and the rear layer, the space between the conjugate type filament is bound by fusion of the component A. In the intermediate layer, the conjugate type filament is divided and split and contains a fiber A consisting of only the component A and a fiber B consisting of only the component B. In the intermediate layer, the fiber A is not substantially interlaced with the component B and the fiber A is not substantially fused. Consequently, in this conjugate filament, a divided and split part and fused part exist.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a three-layer structure suitable for use as a cotton stuffing for clothes, medical hygiene materials, etc., which has excellent bulkiness and heat retention, and has little fluffing and excellent abrasion resistance on the surface. The present invention relates to a nonwoven fabric and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, as a non-woven fabric excellent in bulkiness and heat retaining property, one in which crimped fibers are accumulated is known. For example, a non-woven fabric is known in which the actual crimped fibers are opened and accumulated in a sheet form to obtain a fibrous web, and the crimped fibers in the fibrous web are bonded to each other by some means (Japanese Patent Laid-Open No. Sho 48). -1471, Japanese Patent Publication No. 62-1026, Japanese Patent Laid-Open No.
63-282351 and Japanese Patent Publication No. 52-37097). But,
The actual crimped fibers have a drawback in that the fibers are very easily entangled with each other and are thus difficult to open and accumulate in a sheet form. Therefore, the obtained non-woven fabric has a defect that spots are generated due to poor openability and lack in uniformity.

Further, a latent crimpable fiber which does not develop crimps at the time of opening and which develops crimps after being accumulated in a sheet form is used to form a nonwoven fabric excellent in bulkiness and heat retention. It is also being obtained. As the latently crimpable fiber, a composite type fiber in which two kinds of polymer components having different heat shrinkage rates are combined into a side-by-side type or an eccentric core-sheath type is used. Therefore, in the case of this method, the poor openability can be avoided, but since the composite fiber is heat-shrinked after being accumulated in a sheet shape, the fiber web shrinks, the bulk density becomes high, and the bulkiness is high. It had the drawback of falling.

On the other hand, as a nonwoven fabric excellent in bulkiness and heat retention, there is also known a nonwoven fabric in which ultrafine fibers are accumulated.
For example, a method is known in which composite fibers capable of splitting and splitting are used, and a fiber web obtained by accumulating the composite fibers is subjected to splitting and splitting treatment such as water treatment to generate ultrafine fibers. However, according to this method, there are drawbacks that ultrafine fibers are generated on the front and back surfaces of the obtained non-woven fabric, the surface is easily fluffed, and the abrasion resistance of the surface is poor.
In order to suppress the fuzz on the surface and improve the abrasion resistance of the surface, it is considered that the binder is applied to the surface of the non-woven fabric by means such as spraying. However, the binder causes the entire non-woven fabric to harden, resulting in a new defect that the flexibility is lowered.

[0005]

Therefore, the present invention uses a composite continuous fiber which can be split and split and which has a heat-sensitive adhesive property.
By treating the fibrous web obtained by accumulating the composite long fibers by a specific method, the split split ultrafine fibers are accumulated in the intermediate layer, and the composite long fibers are separated from each other in the front and back layers. Bonded by heat-sensitive adhesive,
An object of the present invention is to provide a non-woven fabric which is hard to be fluffed, has excellent surface abrasion resistance, is bulky, and has excellent heat retention.

[0006]

That is, the present invention provides a three-layer structure nonwoven fabric in which a surface layer, an intermediate layer and a back surface layer are arranged in this order, wherein the front surface layer and the back surface layer are thermoplastic polymers. Component A and a thermoplastic polymer component B, which is incompatible with the component A and has a melting point 30 to 180 ° C. higher than the melting point of the component A, are compounded, and at least the component A is The composite long fibers are exposed on the surface, and the composite long fibers are bonded together by fusion of the component A, and the intermediate layer is formed by splitting the composite long fibers. It contains a fiber A consisting only of the component A and a fiber B consisting only of the component B to be produced, and the fiber A and the fiber B are not substantially entangled, and the fiber A is substantially As a result, the composite long fibers are not fused to A three-layer non-woven fabric comprising a portion existing in the front surface layer and / or the back surface layer and bonded to each other, and a portion existing in the intermediate layer and splitting. And a manufacturing method thereof.

The three-layer structure nonwoven fabric according to the present invention comprises a surface layer,
The intermediate layer and the back surface layer are arranged in this order. These layers are not formed by laminating, but the fibrous web once formed is subjected to a treatment to make the state of the fibers forming each layer different, and as a result, the layers are physically distinguished. is there. Therefore, the fibers forming the front surface layer and / or the back surface layer and the fibers forming the intermediate layer are derived from the same composite continuous fiber.

The front surface layer and the back surface layer are composed of the composite long fibers as shown below. That is, this composite continuous fiber comprises a thermoplastic polymer component A and a thermoplastic polymer component B which is incompatible with the component A and has a melting point 30 to 180 ° C. higher than the melting point of the component A. It is a composite. The component A is at least exposed on the surface of the composite long fiber. The reason for using a thermoplastic polymer as the component A is to bond the composite long fibers to each other by melting or softening the component A. Therefore, the component A must also be at least partially exposed on the surface of the composite continuous fiber. This is because if the component A is not exposed, it cannot be bonded to other composite long fibers due to the fusion. Furthermore, component B is component A
Its melting point is 30-180 ℃ higher, preferably 40-160
℃ higher, most preferably 50-140 ℃ higher. If the melting point difference between the two components is less than 30 ° C., when the component A is melted or softened, the component B is also likely to be softened or deteriorated, and the fiber morphology of the composite long fiber may be broken. This is because the mechanical strength of the layer and the back surface layer is reduced. On the other hand, when the difference in melting point between both components exceeds 180 ° C., it becomes difficult to produce the composite continuous fiber itself by the composite melt spinning method. The melting points of the components A and B are measured by the following method. That is, Perkin Elmer DSC-2C
The melting point was defined as the temperature that gives the extreme value of the melting absorption curve obtained by heating the sample from a room temperature at a heating rate of 20 ° C./min. Further, the component A and the component B must be incompatible polymers. This is because the affinity between the component A and the component B is reduced and the component A and the component B are easily separated.
That is, this is to impart the function of divided splitting to the composite long fibers.

Specific combinations of the components A and B (component A / component B) include polyamide polymers / polyester polymers, polyolefin polymers / polyester polymers, polyolefin polymers / polyamide polymers. A polymer or the like can be used. As the polyester polymer, polyethylene terephthalate, polybutylene terephthalate, or a copolyester having these as a main component can be used. As the polyamide-based polymer, nylon 6, nylon 46, nylon 66, nylon 610, or copolymer nylon having these as the main components can be used. As the polyolefin-based polymer, polypropylene, high-density polyethylene, linear low-density polyethylene, ethylene-propylene copolymer and the like can be used. In addition, component A
Alternatively, in the component B, a lubricant, a pigment, a matting agent, a heat stabilizer, a light resistance agent, an ultraviolet absorber, an antistatic agent, a conductive agent, a heat storage agent and the like may be added, if desired.

The composite long fibers may be compounded in any form as long as they satisfy the above requirements. Specifically, it is preferable that the composite long fibers are compounded so that the cross-sections thereof have the forms shown in FIGS. The component A needs to be exposed at least on the surface of the composite continuous fiber, and both the components A and B may be exposed on the surface of the composite continuous fiber. In the figure, the shaded area is the component B and the scattered area is the component A. In addition, in FIG. 2, the central portion where neither diagonal lines nor scattering points are applied may be hollow (hollow fiber), or may be formed of a polymer component other than the component A and the component B. The composite type long fiber shown in the figure has a substantially circular cross section and is a point symmetric type, but it is not limited to this, and needless to say, it may have an asymmetrical cross section. is there. The quantitative ratio when the component A and the component B are combined is also a matter that can be arbitrarily determined, but in general, component A / component B = 20 to 80/80 to 20 (parts by weight). When the amount of the component A is less than 20 parts by weight, the binding force between the composite type long fibers due to fusion is lowered, and the prevention of fluffing in the front surface layer and the back surface layer and the improvement of abrasion resistance tend to be insufficient. On the other hand, when the amount of the component A exceeds 80 parts by weight, fusion between the composite long fibers becomes severe, and the resulting nonwoven fabric tends to have low flexibility.

The front surface layer and the back surface layer are composed of the composite long fibers as described above, and by fusion of the component A,
They are connected to each other. Therefore, the surface layer and the back surface layer are less likely to fluff and have good wear resistance. The fineness of the composite continuous fiber used in the present invention is a matter that can be arbitrarily determined, but is preferably
It should be between 2 and 12 denier. The fineness of composite long fibers is 2
If it is less than denier, the composite long fibers tend to be too thin and difficult to produce. On the contrary, when the fineness exceeds 12 denier, the rigidity of the composite continuous fiber becomes high, and the flexibility tends to decrease in the front surface layer and the back surface layer. Further, since the composite long fibers are too thick, it tends to be difficult to obtain a surface layer and a back surface layer having a low basis weight and a good texture.

On the other hand, the intermediate layer contains fibers A consisting only of component A and fibers B consisting only of component B, which are produced by splitting the above-mentioned composite long fibers. Of course, the intermediate layer may have a part in which the composite long fibers are not split and the composite long fibers remain in the original form. Moreover, in this intermediate layer, the fibers A and the fibers B are not substantially entangled. Here, “not substantially entangled” means that entanglement by the needle punching method, the water entanglement method, or the like is not performed, and the entanglement between the fibers A and B due to spontaneous twisting or bending is not occurred. It does not mean that it does not exist.
Further, in the front surface layer and the back surface layer, the component A is melted or softened and fused and bonded between the composite long fibers, but in the intermediate layer, the fiber A made of the component A is substantially formed. The fibers A and B are not fused to each other and are not bonded to each other. As described above, the bulkiness of the intermediate layer is maintained because the fibers A and the fibers B are not substantially entangled with each other.

The fineness of the fiber A, which is formed by splitting the composite long fibers and is composed of only the component A, is preferably 0.3 to 2 denier. On the other hand, the fineness of the fiber B composed of only the component B is preferably 0.1 to 0.8 denier. The fineness of the fiber A and the fiber B may be the same,
In many cases, the fiber A has a relatively thick denier. This is because the composite long fibers as shown in FIG. 1 or FIG. 4, that is, the component B is arranged on the surface of the composite long fibers in a large number of divisions, while the component A is the center of the composite long fibers. This is because there are cases in which the composite long fibers that are arranged without being divided into parts are used.

The fiber length of the composite continuous fiber is infinitely long, and therefore, as described above, the composite continuous fiber extends over the front surface layer and / or the back surface layer and the intermediate layer. That is, in the front surface layer and the back surface layer, the composite long fibers are bonded to each other by the fusion of the component A, and the composite long fibers are split and split when they are spread over the intermediate layer. As described above, the three-layer structure nonwoven fabric according to the present invention is formed by accumulating a large number of composite continuous fibers, and each composite continuous fiber has a component in the longitudinal direction in which the sites existing in the front surface layer and the back surface layer are components. The regions A in the intermediate layer, which are bonded to each other by fusion bonding of A, are split and split to form fibers A and B. Therefore, the three-layer structure nonwoven fabric according to the present invention is not one in which the surface layer, the intermediate layer, and the back surface layer are formed simply by laminating, but the surface layers are formed by changing the form of each composite long fiber which is a constituent fiber. , The intermediate layer and the back layer are formed.

The three-layered nonwoven fabric according to the present invention preferably has a bulk density of 0.08 g / cm ³ or less as a whole, that is, including the surface layer, the intermediate layer and the back layer, and 0.06 g / c 3.
It is more preferably m ³ or less, and most preferably 0.04 g / cm ³ or less. When the bulk density exceeds 0.08 g / cm ³ , the bulkiness and heat retention tend to be deteriorated. In addition,
The bulk density is measured by the following method. That is, a total of 5 sample pieces having a sample width of 10 cm and a sample length of 10 cm were prepared, and the basis weight (g / m ² ) of each sample piece was measured.
4.5 g / c using a thickness measuring instrument manufactured by Daiei Kagaku Seiki Seisakusho
The load (m ² ) was applied, the thickness (mm) after standing for 10 seconds was measured, and the apparent density of each of the five sample pieces was calculated by the following formula, and the average value was used as the bulk density. Apparent density (g / c
m ³ ) = [unit weight (g / m ² )] / [thickness (mm)] / 1000. The basis weight of the three-layer structured nonwoven fabric according to the present invention can be arbitrarily determined, but is generally about 50 to 500 g / m ² . Among them, the three-layer non-woven fabric with a relatively low basis weight is used for bedding such as bed sheets and pillow covers, absorbent materials for sanitary materials such as sanitary napkins and disposable diapers, and oil absorbent materials for household or industrial use. It is preferably used. In addition, the three-layer non-woven fabric with a relatively high basis weight is used as a filter material, a cotton pad for sleeping bags and bedding, an extender material, a carpet or artificial leather base cloth, a fertilizer absorbent material for gardening and nurseries, a building or its walls. It is preferably used for heat insulating materials.

The three-layer structure nonwoven fabric according to the present invention is, for example,
It can be manufactured by the following manufacturing method.
First, a thermoplastic polymer component A such as the above-mentioned polyolefin-based polymer is prepared. Then, a thermoplastic polymer component B which is incompatible with the component A and has a melting point higher by 30 to 180 ° C. than the melting point of the component A is prepared. And both components A
And B are introduced into a melt-spinning apparatus equipped with a composite spinneret, and a composite continuous fiber is obtained by a conventionally known composite melt-spinning method. When components A and B are introduced into the composite spinneret, at least a part of component A must be exposed on the surface of the resulting composite continuous fiber. Ingredient A and ingredient B
In order to melt-spin the above, it is sufficient to heat to a temperature 20 to 60 ° C. higher than the melting point of each. Therefore, if the melting point difference between the component A and the component B exceeds 180 ° C., the component A is heated to a temperature extremely higher than its melting point due to the thermal influence of the component B in the molten state, and the component A is decomposed or deteriorated. There is a fear. When the spinning temperature is lower than the above temperature range, it is difficult to increase the spinning speed, and it becomes difficult to obtain fine denier composite long fibers. On the contrary, if the spinning temperature is higher than the above temperature range, the fluidity of the component A and the component B becomes large, and the yarn breakage tends to occur frequently during melt spinning. When yarn breakage occurs, the cut end becomes a ball-shaped lump, and this lump is mixed in the obtained nonwoven fabric, which tends to deteriorate the quality of the nonwoven fabric. Further, when the fluidity of the components A and B becomes large, the vicinity of the spinning hole is easily soiled, and the spinning hole needs to be cleaned at regular intervals, which tends to deteriorate the operability.

The melt-spun composite filaments are then cooled and introduced into air suckers. The air sucker is usually called an air jet, and it causes the fibers to be conveyed and drawn by the action of sucking and sending air. The composite long fiber group introduced into the air sucker is conveyed to the exit of the air sucker while being drawn. Then, the composite long fiber group is opened by an opening device provided at the exit of the air sucker. A conventionally known method is adopted as the opening method, for example, a corona discharge method, a friction charging method, or the like. Then, the opened composite type long fibers are accumulated on a moving collection conveyor made of wire mesh or the like to form a fibrous web.

By applying temperature and, if desired, pressure to the front and back surfaces of this fibrous web, only the component A of the composite continuous fiber present on the front and back surfaces is softened or melted. Then, by fusion-bonding the softened or melted component A, the composite long fibers existing on the front and back surfaces are bonded to each other. A method of applying a temperature to the front and back surfaces of the fibrous web can be performed by bringing a heating roll into contact with the front and back surfaces. For example, it can be done by introducing a fibrous web between a pair of heated steel rolls, or it can be introduced first between the heated steel roll and the cotton roll and then between the cotton roll and the heated steel roll. A fibrous web may be introduced. The latter method is such that the first steel and cotton rolls only apply temperature to the front side of the fibrous web and the subsequent cotton and steel rolls apply temperature only to the back side of the fibrous web. This method is preferable because it is difficult to give a temperature for softening or melting the component A present in the intermediate layer. That is, when the fiber web is introduced between a pair of heated steel rolls as in the former method, high temperatures are simultaneously given to the front and back surfaces,
Heat is easily conducted to the intermediate layer, and there is a possibility that the composite long fibers may be bonded to each other due to fusion of the component A in the intermediate layer.

When using steel rolls and cotton rolls, the linear pressure is preferably 20 to 300 kg / cm. When the linear pressure is less than 20 kg / cm, only heat is applied to the front surface layer or the back surface layer and sufficient pressure cannot be applied, so that the composite continuous fibers in the front surface layer or the back surface layer are hard to bond firmly. If the linear pressure exceeds 300 kg / cm, the pressure may cause the bonding between the composite long fibers existing in the intermediate layer. When a steel roll and a cotton roll are used, the heating temperature of the steel roll is preferably a temperature above the softening point of component A and below the melting point of component A. When the heating temperature of the steel roll is lower than the softening point of the component A, the fusion of the component A does not cause bonding between the composite long fibers. On the contrary, the heating temperature of the steel roll is component A
When the melting point exceeds the melting point of, the component A of the composite continuous fiber in the intermediate layer may be softened, and the composite continuous fiber in the intermediate layer may be bonded.

As another method of applying temperature to the front and back surfaces of the fiber web, there is a method of applying radiant heat to the front and back surfaces of the fiber web, or a method of blowing hot air onto the front and back surfaces of the fiber web. When such a method is adopted, it is preferable that radiant heat or hot air is not applied to the intermediate layer, and the temperature is not lower than the melting point of component A and lower than the melting point of component B. In the case of such a method, since pressure is not applied to the front and back surfaces of the fibrous web, it is not possible to firmly bond the composite long fibers to each other only by softening the component A, and the component A is melted to form a composite. The long fibers are firmly bonded to each other. In addition, when applying temperature to the front and back surfaces of the fibrous web, it is needless to say that the above method using a steel roll or the like and this method using radiant heat or hot air may be used in combination.

As described above, a fiber fleece is obtained in which the composite long fibers are bonded to each other on the front and back surfaces and the composite long fibers are simply accumulated in the intermediate layer. Then, the fiber fleece is subjected to a kneading process. As a method of kneading, for example, when introducing the fiber fleece into the roll, a buckling compression method in which the introduction speed is slower than the derivation speed to bend the fiber fleece, a high pressure liquid flow for applying a high pressure liquid flow to the fiber fleece. Treatment methods can be applied. Also,
In addition to this method, any method can be applied as long as a rubbing action of splitting the composite long fibers is added to the fiber fleece. When the buckling compression method is adopted, it is preferable to use a Microcreper machine manufactured by Mike Rex or a cam fit machine manufactured by Uenoyama Kiko Co., Ltd. Further, when the high pressure liquid stream treatment method is adopted, it is preferable to use a commonly used high pressure liquid stream dyeing machine. In the case of the high-pressure liquid flow treatment method, the fiber fleece absorbs water, so it is necessary to dry after treatment, but in the case of the buckling compression method, since this is not the case, the drying step is unnecessary and it is economical. It is advantageous.

By the above-mentioned rubbing process, the composite long fibers in the intermediate layer are split and split to produce fibers A consisting of only component A and fibers B consisting of only component B. Fiber A with a fineness smaller than that of the composite long fiber
By the formation of the fibers B and the intermediate layer, the flexibility and the bulkiness of the intermediate layer are improved, and the heat retention is also improved.
On the other hand, since the composite long fibers existing in the front and back layers are bonded to each other by fusion of the component A, they are hardly split and split. The non-woven fabric thus obtained has a three-layer structure consisting of a surface layer, an intermediate layer, and a back layer, and in the front and back layers, the composite long fibers are bonded to each other by fusion of the component A, In the intermediate layer, the fibers A and the fibers B produced by the split splitting of the composite long fibers are accumulated without being bound or entangled.

[0023]

EXAMPLES The present invention will be described in more detail with reference to examples. The methods of measuring the physical properties shown in the examples are as follows. (1) Melt index value (hereinafter, simply abbreviated as “MI value”): Measured by the method described in ASTM D1238 (E). (2) Tensile strength of non-woven fabric: In accordance with the strip method described in JIS L-1096, 10 pieces of sample width 5 cm and sample length 10 cm were prepared, and the maximum strength was individually obtained under the condition of pulling speed 10 cm / min. The tensile strength was determined by measuring and converting the average value into a basis weight of 100 g / m ² . (3) Tensile elongation of nonwoven fabric: When measuring tensile strength, the elongation at which the maximum strength was exhibited was defined as the tensile elongation. (4) Compressive stiffness of non-woven fabric: First, set the sample width in the longitudinal direction of the non-woven fabric and the sample length in the lateral direction of the non-woven fabric, and sample 5 pieces with a sample width of 50 mm and a sample length of 100 mm. prepare. Here, the longitudinal direction of the non-woven fabric is the arrangement direction of the machine at the time of manufacturing the non-woven fabric, and the lateral direction of the non-woven fabric is
It is the direction orthogonal to the vertical direction. Then, bend this sample piece in the lateral direction (sample length direction), height 50 mm, circumference
Create a 100mm cylinder. Using a Tensilon tensile tester UTM-4-1-100, this cylinder was compressed in the height direction (the sample width direction, that is, the longitudinal direction of the nonwoven fabric) at a compression speed of 50 mm / min. The stress at the maximum load was measured. This measurement was performed on five cylinders, and the average value was taken as the compression stiffness. The compression bending softness represents the flexibility of the nonwoven fabric, and the smaller the value, the more flexible the nonwoven fabric.

Example 1 As the thermoplastic polymer component A, the melting point was 132 ° C. and the MI value was 2
A high density polyethylene having 0 g / 10 minutes, a density of 0.955 g / cm ³ , and a Q value (weight average molecular weight / number average molecular weight) of 5.0 was prepared. On the other hand, as the thermoplastic polymer component B, the melting point is
A polyethylene terephthalate having a relative viscosity of 1.38 at 20 ° C when dissolved in an equal amount of a mixed solvent of tetrachloroethane and phenol at 256 ° C was prepared. Then, component A and component B were used to perform composite melt spinning. At this time, a composite spinning machine base having a spinneret having 162 nozzle nozzle holes and having 4 spindles was used. And the single hole discharge rate is 1.30
The composite melt spinning was performed so that the discharge amount of component A was 0.65 g / min and the discharge amount of component B was 0.65 g / min. The spinning temperature was 250 ° C. for component A and 290 ° C. for component B.

After the composite melt spinning, the composite continuous fiber was pulled through 6 air suckers per spindle. The cross section of the thus obtained composite continuous fiber had a form as shown in FIG. 1, and the fineness thereof was 2.95 denier. Therefore, the converted spinning speed was 3950 m / min. Subsequently, the pulled composite type continuous fiber group was opened by corona discharge and deposited on a conveyor net moving at a speed of 5 m / min to form a fiber web. This fibrous web was introduced between a steel roll heated to 120 ° C. and a cotton roll at room temperature, and subsequently between a cotton roll at room temperature and a steel roll heated to 120 ° C. The linear pressure between the steel roll and the cotton roll was 100 kg / cm. In this manner, the front surface and the back surface of the fiber web contacting the steel roll are heat-treated to fuse the component A (polyethylene) of the composite continuous fiber existing on the front surface and the back surface of the fiber web to form the composite fiber. The fibers were bonded together.

As described above, a fiber fleece was obtained in which the composite long fibers were bonded to each other in the front surface layer and the back surface layer, and the composite long fibers were simply accumulated in the intermediate layer. The fiber fleece was kneaded by using a device as shown in FIG. This device is a Microcreper II manufactured by Mike Rex Co., Ltd. The conditions were set as follows. That is, the processing speed is 10 m / min, the nip pressure of the supply rolls 1 and 2 is 6 kg / cm ² , the pressure of the upper retarder 3 is
3 kg / cm ² , temperature of supply rolls 1 and 2 50 ° C, pressure of lower retarder 4 5 kg / cm ² , distance of contact pressure center point between supply rolls 1 and 2 and upper retarder 3 5 mm, between supply rolls 1 and 2 The distance between the center of contact pressure and the lower retarder 4 was 10 mm. In FIG. 5, 5 is a fiber fleece, and 6 is the obtained three-layer structure nonwoven fabric.

In the intermediate layer, the obtained three-layer structure nonwoven fabric was prepared by mixing and rubbing 0.19 denier ultrafine polyethylene terephthalate fibers and 1.5 denier polyethylene fibers produced by splitting the composite long fibers by rubbing. In the front surface layer and the back surface layer, the composite long fibers were bonded to each other by fusion bonding of polyethylene in the composite long fibers. Therefore, this three-layer structure nonwoven fabric was obtained by wrapping an aggregate of ultrafine fibers in a non-woven thin film in which the fibers were bonded together, and had the following physical properties. Therefore, it was bulky and excellent in flexibility, less fluffing on the front and back surfaces, excellent in abrasion resistance, and excellent in handleability when used as a stuffed cotton sheet. Unit weight: 98 g / m ² Tensile strength: 10.4 kg / 5 cm Tensile elongation: 89% Compressive bending resistance: 1 g Bulk density: 0.013 g / cm ³

Example 2 As the thermoplastic polymer component A, nylon 6 having a relative viscosity of 2.60 measured at 25 ° C. with concentrated sulfuric acid having a melting point of 225 ° C. and 96% was prepared. On the other hand, as the thermoplastic polymer component B,
The same polyethylene terephthalate as used in Example 1 was prepared. Then, using the components A and B,
Composite melt spinning was performed. At this time, a hollow radial type composite spinning hole for 16 divisions is used so that a composite long fiber having a cross section as shown in FIG.
Composite melt spinning was performed in the same manner as in Example 1 except that the temperature was 265 ° C.

Then, it was pulled by an air sucker in the same manner as in Example 1 to obtain a composite continuous fiber having a cross section as shown in FIG. 2 and a fineness of 3.0 denier.
The converted spinning speed was 4050 m / min. Subsequently, a fibrous web was formed in the same manner as in Example 1, and a fiber fleece was obtained in the same manner as in Example 1 except that the temperature of the steel roll was set to 200 ° C. This fiber fleece was subjected to the same rubbing process as in Example 1 to obtain a three-layer structure nonwoven fabric.

In the intermediate layer, the obtained three-layer structured non-woven fabric was obtained by mixing 0.2-denier ultrafine polyethylene terephthalate fibers and nylon 6 fibers produced by splitting the composite long fibers by rubbing and mixing them together. Cage,
In the front surface layer and the back surface layer, the composite long fibers were bonded to each other by fusion bonding of nylon 6 in the composite long fibers. Therefore, this three-layer structure nonwoven fabric was obtained by wrapping an aggregate of ultrafine fibers in a non-woven thin film in which the fibers were bonded together, and had the following physical properties. Therefore, it was bulky and excellent in flexibility, less fluffing on the front and back surfaces, excellent in abrasion resistance, and excellent in handleability when used as a stuffed cotton sheet. Unit weight: 102 g / m ² Tensile strength: 15.3 kg / 5 cm Tensile elongation: 83% Compression stiffness: 1 g Bulk density: 0.021 g / cm ³

Example 3 The fiber fleece obtained in Example 2 was subjected to rubbing using a loco type jet dyeing machine (manufactured by Hokuriku Processing Machine). And
Simultaneously with the rubbing process, the nylon 6 component in the fiber fleece and the nylon 6 ultrafine fibers produced by the rubbing process were dyed. The dyeing conditions are: Blue FFB (Sumitomo Chemical Co., Ltd.) 0.2% owf as an acid dye, Migregar WA-10 (Senka) 0.5 g / l as acetic acid dye, and acetic acid PH5.
2000 l of an aqueous solution dissolved so that In addition, the conditions for applying a liquid flow to the fiber fleece are a liquid temperature of 100
℃, fiber fleece speed 100m / min, nozzle pressure 3kg / cm
² , 1 hour. After rubbing and dyeing with a roco jet dyeing machine, dehydration and drying were performed to obtain a three-layer structure nonwoven fabric.

In the intermediate layer, the obtained three-layer structured non-woven fabric was prepared by kneading and mixing 0.2 denier ultrafine nylon 6 fibers and polyethylene terephthalate fibers produced by split splitting of composite long fibers in a mixed state. Cage,
In the front surface layer and the back surface layer, the composite long fibers were bonded to each other by fusion bonding of nylon 6 in the composite long fibers. Therefore, this three-layer structure nonwoven fabric was obtained by wrapping an aggregate of ultrafine fibers in a non-woven thin film in which the fibers were bonded together, and had the following physical properties. Furthermore,
The whole was dyed blue. Therefore, it was bulky and excellent in flexibility, had little fuzz on the front and back surfaces, and was excellent in abrasion resistance, and could be suitably used as a pillow cover or bed sheets. Unit weight: 123g / m ² Tensile strength: 14.2kg / 5cm Tensile elongation: 88% Compression stiffness: 5g Bulk density: 0.025g / cm ³

Comparative Example 1 In the same manner as in Example 1, a fibrous web was obtained. And
This fibrous web was introduced into an embossing machine consisting of uneven rolls and smooth rolls. The embossing conditions were that the total area of the protrusions of the concavo-convex roll was 13% of the roll surface area, the heating temperature of the concavo-convex roll was 125 ° C, and the linear pressure between the concavo-convex roll and the smooth roll was 50 kg / cm. In this way a fiber fleece with spaced fusion zones was obtained. In the fusion-bonded area, the composite long fibers were bonded to each other by polyethylene fusion even from the front surface to the back surface, that is, in the intermediate layer. This fiber fleece was rubbed under the same conditions as in Example 1 to obtain a nonwoven fabric.

This non-woven fabric has a fusion-bonded area and a non-fusion-bonded area, and the composite long fibers in the non-fusion-bonded area are split and split to form ultrafine polyethylene fibers and polyethylene terephthalate fibers. It was However, since fibers were not bonded to each other on the front and back surfaces of the non-fused area, fluffing was severe in this area and abrasion resistance was poor. In the fusion zone, since the composite long fibers are bonded to each other from the front surface to the back surface of the non-woven fabric, the bulkiness and flexibility of this area are low, and the bulkiness and flexibility of the entire area are low. Was inferior to Therefore, it was not suitable to use this non-woven fabric as a stuffed cotton sheet. The physical properties of this nonwoven fabric were as follows. Unit weight: 100 g / m ² Tensile strength: 30.8 kg / 5 cm Tensile elongation: 51% Compression stiffness: 11 g Bulk density: 0.136 g / cm ³

[0035]

FUNCTION AND EFFECTS OF THE INVENTION Certain specific composite long fibers used in the present invention function as both heat-sensitive adhesive fibers and split fibers. Then, paying attention to this function, in the front surface layer and the back surface layer of the fibrous web in which the composite long fibers are accumulated, heat-sensitive adhesiveness is expressed,
The composite long fibers are bonded to each other, and in the intermediate layer of the fibrous web, the function of the split fibers is developed to generate ultrafine fibers from the composite long fibers. Therefore, the resulting nonwoven fabric has a three-layer structure of a surface layer, an intermediate layer, and a back surface layer, and since the composite long fibers are bonded to each other in the surface layer and the back surface layer, fluffing is less likely to occur, Further, it has an effect of being excellent in wear resistance. Further, since the ultrafine fibers are accumulated in the intermediate layer, it is possible to obtain an effect that the bulkiness is excellent, the heat retaining property is excellent, and the flexibility is excellent. Therefore, this three-layer structure nonwoven fabric has the effects of being less prone to fluffing, excellent in abrasion resistance, and excellent in flexibility, bulkiness, and heat retention.
Further, the fibers present in the surface layer and / or the back surface layer and the intermediate layer are derived from the same composite continuous fiber although the states thereof are different, and the composite continuous fiber is formed from the front surface layer or the back surface layer. It spans the middle layer. Therefore, the front surface layer and the intermediate layer, or the intermediate layer and the back surface layer are not simply bonded together, and thus also have an effect that delamination is difficult.

[Brief description of drawings]

FIG. 1 is a view showing an example of a cross section of a composite continuous fiber used in the present invention.

FIG. 2 is a view showing an example of a cross section of a composite continuous fiber used in the present invention.

FIG. 3 is a view showing an example of a cross section of a composite continuous fiber used in the present invention.

FIG. 4 is a view showing an example of a cross section of a composite continuous fiber used in the present invention.

FIG. 5 is an enlarged side view showing an example of an apparatus used for kneading in the present invention.

[Explanation of symbols]

 5 Fiber web 6 Fiber fleece

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[Procedure amendment]

[Submission date] December 31, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 4

[Correction method] Change

[Correction content]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0003

[Correction method] Change

[Correction content]

Further, a latent crimpable fiber which does not develop crimps at the time of opening and which develops crimps after being accumulated in a sheet form is used to form a nonwoven fabric excellent in bulkiness and heat retention. It is also being obtained. It is a latent crimpable fiber,
A composite fiber in which two kinds of polymer components having different heat shrinkage rates are compounded in a side-by-side type or an eccentric core-sheath type is used. Therefore, in the case of this method, the poor openability can be avoided, but since the composite fiber is heat-shrinked after being accumulated in a sheet shape, the fiber web shrinks,
The bulk density is high, and the bulkiness is low.

[Procedure 3]

[Document name to be amended] Statement

[Name of item to be corrected] 0015

[Correction method] Change

[Correction content]

The three-layered nonwoven fabric according to the present invention preferably has a bulk density of 0.08 g / cm ³ or less as a whole, that is, including the surface layer, the intermediate layer and the back layer, and 0.06 g / c 3.
It is more preferably m ³ or less, and most preferably 0.04 g / cm ³ or less. When the bulk density exceeds 0.08 g / cm ³ , the bulkiness and heat retention tend to be deteriorated. In addition,
The bulk density is measured by the following method. That is, a total of 5 sample pieces having a sample width of 10 cm and a sample length of 10 cm were prepared, and the basis weight (g / m ² ) of each sample piece was measured.
4.5 g / c using a thickness measuring instrument manufactured by Daiei Kagaku Seiki Seisakusho
The load (m ² ) was applied, the thickness (mm) after standing for 10 seconds was measured, and the apparent density of each of the five sample pieces was calculated by the following formula, and the average value was used as the bulk density. Apparent density (g / c
m ³ ) = [unit weight (g / m ² )] / [thickness (mm)] / 1000. The basis weight of the three-layer structured nonwoven fabric according to the present invention can be arbitrarily determined, but is generally about 15 to 500 g / m ² . Among them, the three-layer non-woven fabric with a relatively low basis weight is used for bedding such as bed sheets and pillow covers, absorbent materials for sanitary materials such as sanitary napkins and disposable diapers, and oil absorbent materials for household or industrial use. It is preferably used. In addition, the three-layer non-woven fabric with a relatively high basis weight is used as a filter material, a cotton pad for sleeping bags and bedding, an extender material, a carpet or artificial leather base cloth, a fertilizer absorbent material for gardening and nurseries, a building or its walls. It is preferably used for heat insulating materials.

Claims (4)

[Claims] 1. A three-layer structured non-woven fabric in which a surface layer, an intermediate layer and a back surface layer are arranged in this order, wherein the front surface layer and the back surface layer are thermoplastic polymer component A.
And a thermoplastic polymer component B which is incompatible with the component A and has a melting point higher by 30 to 180 ° C. than the melting point of the component A, and at least the component A is present on the surface thereof. The composite long fibers are exposed, and the composite long fibers are bonded together by fusion of the component A, and the intermediate layer is formed by splitting the composite long fibers. ,
It contains a fiber A consisting only of the component A and a fiber B consisting only of the component B, and the fiber A and the fiber B are not substantially entangled, and the fiber A is substantially fused. As a result, the composite continuous fiber is divided in the longitudinal direction from the portion existing in the front surface layer and / or the back surface layer and bonded to each other and the portion existing in the intermediate layer. A three-layer structure non-woven fabric, which is characterized in that it has a part that is fine. 2. The three-layer structure according to claim 1, wherein the composite continuous fiber has a fineness of 2 to 12 denier, the fiber A has a fineness of 0.3 to 2 denier, and the fiber B has a fineness of 0.1 to 0.8 denier. Non-woven fabric. 3. The three-layer structured non-woven fabric according to claim 1, wherein the total bulk density is 0.08 g / cm ³ or less. 4. A thermoplastic polymer component A, which is incompatible with the component A and which has a melting point of the component A of 30 to 180.
The composite long fibers in which at least the component A is exposed on the surface of the thermoplastic polymer component B, which is composited with the thermoplastic polymer component B having a high melting point of 0 ° C., are integrated to form a fibrous web. By giving the back surface a temperature at which only the component A is softened or melted, the component A is fused only on the front and back surfaces of the fiber web to obtain a fiber fleece in which the composite long fibers are bonded to each other. By subjecting the fiber fleece to a rubbing process, the composite long fibers which are present in the intermediate layer except the front and back surfaces of the fiber fleece and which are not bonded to each other are split into fibers A containing only the component A. And a method for producing a three-layered nonwoven fabric, which comprises producing a fiber B consisting of only the component B.