JPH1096154A - Stretchable blended nonwoven fabric and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a blended nonwoven fabric excellent in stretchability in one direction. SOLUTION: This nonwoven fabric is obtained by blending high-melting point polyester-based filament with low melting point polyester-based filament and accumulating the blend. The area in which high melting point filaments are mutually melted is provided in scattered pointlike state by softening or melting of a low melting point filament. The nonwoven fabric satisfies conditions comprising (i) >=150% breakage elongation in width direction of nonwoven fabric, (ii) 15 ratio of breaking elongation in width direction to breaking elongation in vertical direction of a nonwoven fabric, (iii) >=60% elongation recovery obtained when the nonwoven fabric the nonwoven fabric is elongated in 50% in the width direction and (iv) >=50% elongation recovery obtained when the nonwoven fabric is stretched by 100% in the width direction. Heat is partially applied to a fiber weave in which high melting point fiber and low melting filament are accumulated to provide a fiber fleece. The fiber fleece is spread in width direction and thermally drawn at a draw ratio of 10-80% and thermally set to provide the objective stretchable blended nonwoven fabric.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mixed fiber nonwoven fabric comprising two kinds of long fibers having different melting points as constituent fibers and a method for producing the same, and more particularly to a mixed fiber nonwoven fabric having excellent unidirectional elasticity and a method for producing the same. It is about.

[0002]

2. Description of the Related Art Conventionally, nonwoven fabrics have been used for various purposes such as clothing, industrial materials, civil engineering materials, agricultural and horticultural materials, living related materials, and medical hygiene materials. Among them, in particular, nonwoven fabrics used for medical hygiene materials such as surface materials of disposable diapers, base cloth of puppet materials, sports supporters or bandages, etc., are easy to follow the movement of the human body and easily adapt to the human body. For this reason, elasticity is required. In order to impart elasticity to a nonwoven fabric, a method of using crimped fibers having good elasticity as a fiber constituting the nonwoven fabric, or a method of using a polyurethane fiber or the like having a material itself having elasticity is known. ing.

[0003] As the technology belonging to the former, the following are mentioned. For example, JP-A-63-28960 discloses a stretchable nonwoven fabric obtained by subjecting a latently crimpable short fiber web to a hydroentanglement and then performing a heat treatment to make the latently crimp visible. JP-A-2-91217 discloses that
After performing needle punch on the latently crimpable short fiber web,
A stretchable nonwoven fabric that has been subjected to heat treatment to make latent crimps visible is disclosed. In Japanese Patent Publication No. 4-46145, in the spinning process, a spun yarn having an irregular cross section is subjected to single-side cooling to impart a cooling strain, and utilizing this strain, a manifest or latent crimp is converted into a long fiber. A stretchable nonwoven fabric which is provided with the long fibers as constituent fibers is disclosed. Tokiwa 4-46
No. 147 discloses two kinds of polymers having different heat shrinkages,
A stretchable nonwoven fabric has been disclosed in which a fibrous web formed by accumulating conjugate long fibers composited in a side-by-side or eccentric core-sheath type is subjected to a heat treatment so that the long fibers exhibit crimps with different heat shrinkages. The technology belonging to the latter is disclosed in
Japanese Patent Application Laid-Open No. 9-223347 discloses a stretchable nonwoven fabric using thermoplastic polyurethane elastic fibers as constituent fibers.
All of these techniques use stretchable fibers as fibers constituting the nonwoven fabric.

[0004] On the other hand, there is also known a nonwoven fabric which exhibits elasticity mainly due to the structure of the nonwoven fabric without using stretchable fibers as constituent fibers. For example, the fiber fleece obtained by the melt blown method, in which the constituent fibers are randomly arranged, is subjected to thermal drawing, and the arrangement is changed so that the constituent fibers are arranged in the longitudinal direction, and the elasticity in the width direction is changed. There is known a method for producing a nonwoven fabric provided with a nonwoven fabric (US Pat. No. 5,244,482). However, since the constituent fibers of this nonwoven fabric are composed of only one kind of constituent fibers, when the constituent fibers are heat-sealed to each other, the fiber form collapses at the fused portion and no fibers remain, and the breaking strength (tensile strength) is reduced. In some cases, it was difficult to obtain a large elastic nonwoven fabric. Further, in order to obtain the constituent fibers by the melt blown method, only constituent fibers having a small fiber diameter (small fineness) were obtained, which also made it difficult to obtain an elastic nonwoven fabric having a large breaking strength.

Further, the nonwoven fabric obtained by this method has good stretchability in the width direction, but the size of the voids between the constituent fibers is reduced, and the nonwoven fabric having a high fiber density (porosity) is obtained. Is small). That is, US Pat.
According to the specification of No. 82, the size of the gap between the constituent fibers in the obtained stretchable nonwoven fabric is 80% of the size of the gap between the constituent fibers in the fiber fleece.
It is described as follows. Depending on the use of the stretchable nonwoven fabric, such a decrease in voids, that is, a decrease in porosity, and a low breaking strength may be acceptable. For example, it can be used as a filtering material for filtering fine dust. However, if it is used for other uses, especially for medical hygiene materials such as disposable diaper surface materials applied to the human body, base cloth for pulp, sports supporters, bandages, etc., the decrease in porosity and low tensile strength are Gives undesired results. That is, since a stretchable nonwoven fabric having a small porosity has low air permeability, when it is used as a sports supporter or the like, there is a drawback that sweaty sweat easily occurs and gives a user discomfort. In addition, since the liquid permeability is low, when used as a surface material of a disposable diaper, there is a drawback that a bodily fluid hardly permeates into an absorbent body of the disposable diaper body, and the bodily fluid leaks. Further, if the breaking strength is low, there is a drawback that the film breaks during use.

[0006]

SUMMARY OF THE INVENTION Accordingly, the present invention is directed to a method of mixing two types of long fibers, a high-melting long fiber and a low-melting long fiber, in which each of the long fibers is relatively randomly accumulated. Subjecting a fiber fleece to a fiber fleece, comprising a plurality of high-melting long fibers that are bonded by softening or melting of low-melting long fibers, in which a heat-fused area is scattered. Thus, a long-fiber nonwoven fabric having a structure that easily exhibits elasticity in one direction and having a desired porosity and tensile strength was successfully obtained, and the present invention has been achieved.

[0007] As a method for imparting heat drawing to a fiber fleece having a heat-sealed area formed by a general spunbonding method, Japanese Patent Publication No. 57-54583 and Japanese Patent Application Laid-Open No. 2-353 / 1985 are known.
Although the technique described in Japanese Patent No. 3369 is known, it is crucially different in that the technique is not intended to exert the elasticity as in the present invention. That is, the former technique aims at obtaining a nonwoven fabric having a good feel and excellent drapability, and a method of partially cutting constituent fibers by applying heat drawing to a fiber fleece. is there. In addition, the latter technique aims at obtaining a nonwoven fabric having less fuzz, excellent tensile strength and elongation properties and excellent feeling, and uses a low crystallinity and low orientation unstretched long fiber to form a fiber fleece. By forming and subjecting the fiber fleece to hot drawing, the undrawn long fibers are converted into highly crystalline and highly oriented long fibers. In other words, the technique is to convert the fibers in the fiber fleece into long fibers having good physical properties after obtaining the fiber fleece. Further, in the former two techniques, since only a kind of long fiber having the same melting point is used as a constituent fiber, it is difficult to control the temperature of heat fusion at the time of forming a fiber fleece. That is, if the temperature at the time of heat fusion is high, the long fiber form completely collapses in the heat fusion area,
Holes are opened or cut by thermal stretching. Also,
If the temperature at the time of heat fusion is low, the fusion is incomplete, and the nonwoven fabric itself collapses during hot stretching.

In the present invention, the fiber fleece is subjected to hot stretching similarly to the former two techniques. However, the object of the present invention is to obtain a nonwoven fabric having excellent elasticity. The nonwoven fabric is a nonwoven fabric that is accumulated in a mixed state with long fibers, and is a nonwoven fabric in which fusion areas formed by softening or melting low-melting long fibers between high-melting long fibers are scattered. In some respects, and as a manufacturing method, the fiber fleece is expanded in the width direction as desired before hot drawing,
The difference is that heat setting is performed after heat stretching.

[0009]

According to the present invention, the high-melting polyester filaments and the low-melting polyester filaments are integrated in a mixed state, and the high-melting polyester filaments are mixed with each other. A stretched mixed nonwoven fabric in which a fusion zone in which the space is fused by softening or melting of the low-melting polyester long fiber is provided in a scattered manner, and is a width direction (also referred to as a lateral direction) of the nonwoven fabric. ) Is 150%
The ratio of the elongation at break in the width direction to the elongation at break in the longitudinal direction (also referred to as the machine direction) is 5 or more, and the elongation recovery rate when the nonwoven fabric is stretched 50% in the width direction. Is 60% or more, and a stretch recovery ratio when stretched by 100% in the width direction is 50% or more.

The present invention also provides a fiber web in which high-melting polyester long fibers and low-melting polyester long fibers are deposited on a collecting conveyor, and both fibers are accumulated in a mixed state. Heat is partially applied to the fibrous web to disperse into the fibrous web a fused area where the high-melting polyester filaments are fused by softening or melting the low-melting polyester filaments. After obtaining the fiber fleece provided in the form of dots, the fiber fleece is expanded in the width direction at a width of 0%.
The fiber fleece is thermally stretched in the machine direction at a stretching ratio of 10 to 80% in a state where the fiber fleece is widened so as to be 50%.
The present invention relates to a method for producing a stretchable mixed nonwoven fabric, which is heat-set at a temperature not higher than the melting point of the low-melting polyester fiber.

The stretchable mixed nonwoven fabric according to the present invention comprises high-melting polyester long fibers and low-melting polyester long fibers as constituent fibers. The high melting polyester long fiber is obtained by melt-spinning a high melting polyester polymer. As the high-melting-point polyester polymer, polyethylene terephthalate is used, or a polyester whose main repeating unit is an ethylene terephthalate unit is used. In the case of the latter polyester,
As the component other than the ethylene terephthalate unit, a conventionally known acid component and / or alcohol component can be used. The copolymerized polyester obtained by adding such a copolymerization component has a lower melting point than polyethylene terephthalate, but as long as the melting point is not lower than the melting point of the low melting point polyester-based polymer used in the present invention, the high melting point polyester-based polymer is used. It can be used as a union. As a conventionally known acid component, isophthalic acid, adipic acid, or the like can be used. In addition, as the alcohol component, propylene glycol, diethylene glycol, or the like can be used.

The low melting polyester long fiber is obtained by melt-spinning a low melting polyester polymer. As the low-melting polyester polymer, a copolymer polyester whose main repeating unit is an ethylene terephthalate unit is employed. In particular, it is preferable to employ a copolymerized polyester in which an ethylene terephthalate unit is 70 to 95 mol% and a conventionally known acid component and / or alcohol component is copolymerized. As described above, a copolymerized polyester can also be used as the high-melting-point polyester polymer.In this case, a copolymerized polyester having a melting point lower than the melting point of the high-melting-point polyester polymer is used. What is necessary is just to employ | adopt as a melting-point polyester polymer. Note that, as specific examples of the acid component and the alcohol component, those similar to those described above can be employed.

The high-melting-point polyester polymer and the low-melting-point polyester polymer may optionally contain various additives such as matting agents, pigments, light stabilizers, heat stabilizers, antioxidants, crystallization accelerators and the like. Additives may be added within a range that does not impair the purpose of the present invention.

The fineness of the high-melting polyester long fiber and the low-melting polyester long fiber is preferably 15 denier or less. When the fineness exceeds 15 denier, the rigidity of each long fiber increases, the coarseness of the stretchable mixed nonwoven fabric increases, and it becomes difficult to use it for general-purpose applications. Here, the fineness of each long fiber means the fineness of each long fiber in the obtained nonwoven fabric, and each long fiber in the fiber fleece before stretching may be slightly larger than 15 denier. However, when the fineness of each long fiber in the fiber fleece greatly exceeds 15 denier and becomes thick, it may hinder the cooling and solidification of the spun yarn in the melt spinning process, or the operability may be deteriorated even in the fiber fleece drawing process. It tends to be inferior.

The proportion of the high-melting polyester long fiber and the low-melting polyester long fiber in the stretchable mixed-fiber nonwoven fabric is as follows: high-melting polyester long fiber: low-melting polyester long fiber = 1: 0.1 to The weight ratio is preferably 5, and more preferably 1: 0.2 to 4 parts by weight. That is, in the stretchable mixed-fiber nonwoven fabric, 100 parts by weight of the high-melting polyester long fiber is preferably 10 to 500 parts by weight of the low-melting polyester long fiber,
In particular, it is more preferably 20 to 400 parts by weight. In the stretchable mixed nonwoven fabric, this low-melting polyester long fiber functions as a fusion component (adhesion component) between the high-melting polyester long fibers. Therefore, if the low-melting polyester long fiber is less than the above range, fusion between the high-melting polyester long fibers becomes insufficient,
The tensile strength of the nonwoven fabric may be low. In addition, when the fiber fleece is subjected to thermal drawing, the fusion between the high-melting polyester long fibers may peel off, and the high-melting polyester long fibers may come off. Further, if the number of low-melting polyester long fibers exceeds the above-mentioned range, the fusion in the fusion area becomes severe, and the proportion of the high-melting polyester long fibers maintaining the fiber form in the fusion area is increased. Therefore, holes may be opened in the fusion zone during the heat stretching.

The stretchable mixed nonwoven fabric according to the present invention is provided with a large number of scattered spots in which high-melting polyester long fibers are fused to each other. In this fusion zone, the high-melting polyester filaments are fused by softening or melting the low-melting polyester filaments, and the high-melting polyester filaments generally maintain the original fiber form. It exists as is or in slightly deformed fiber form. The shape of each fused area may be any shape such as a round shape, an elliptical shape, a diamond shape, a triangular shape, a T shape, a well shape, a rectangular shape, etc., but is not a clear shape but a somewhat unclear shape. ing. This is because the form is distorted by the hot stretching. Further, the size of each fused area is preferably about 0.2 to 6.0 mm ² . Furthermore,
The distance between adjacent fusion zones is 0.3 to 2 mm at short places
And about 1 to 10 mm at a long place. In addition, the total area of the fusion zone is 2 to the surface area of the nonwoven fabric.
It is preferably about 50%, particularly preferably 5 to 25%.

The stretchable mixed nonwoven fabric having the above structure has specific physical properties and satisfies the following four conditions at the same time. First, the elongation at break in the width direction of the nonwoven fabric must be 150% or more. If the breaking elongation is less than 150%, the stretchability of the nonwoven fabric in the width direction is insufficient, and good stretchability cannot be exhibited. Second, the ratio of the breaking elongation in the width direction of the nonwoven fabric to the breaking elongation in the longitudinal direction of the nonwoven fabric must be 5 or more. If this ratio is less than 5, the elongation in the width direction does not significantly increase as compared with the elongation in the vertical direction, and it cannot be said that the material has good elasticity in one direction. Elongation at break (%)
Is measured according to the method described in JIS-L-1096A. That is, a strip-shaped sample piece 1 having a sample width of 5 cm
Using a constant-speed elongation type tensile tester (Tensilon UTM-4-1-100 manufactured by Toyo Baldwin Co.), each sample piece was set at a distance of 5 cm between the chucks and a tensile speed of 10 c.
The sample elongated at m / min, and the average elongation when each specimen was broken was defined as the elongation at break (%). Therefore, the elongation at break (%) =
{[(Distance between chucks at break)-(5)] / (5)}
It is calculated by × 100. When the elongation at break in the width direction of the nonwoven fabric is measured, the elongation of the strip-shaped sample is measured so that the longitudinal direction is the width direction of the nonwoven fabric, and the elongation at break in the longitudinal direction of the nonwoven fabric is measured. In this case, it is needless to say that the measurement is performed by elongating the strip-shaped sample piece so that the longitudinal direction of the strip is the longitudinal direction of the nonwoven fabric.

Third, the elongation recovery rate when the nonwoven fabric is stretched by 50% in the width direction must be 60% or more. When the elongation recovery rate is less than 60%, after the external force is applied to stretch the nonwoven fabric in the width direction, the shrinkage when the external force is released is insufficient, and good elasticity is not exhibited.
Fourth, the elongation recovery rate when the nonwoven fabric is stretched 100% in the width direction must be 50% or more. Even when the elongation recovery rate is less than 50%, good stretchability is not exhibited. This elongation recovery rate is JIS-L-1096
It is measured by the following method according to the method described in 6.13.1A. First, five strip-shaped sample pieces each having a sample width of 5 cm are prepared. At this time, the longitudinal direction of the strip-shaped sample piece is set to be the width direction of the nonwoven fabric. Then, a constant speed elongation type tensile tester (Tensilon U manufactured by Toyo Baldwin Co., Ltd.)
Using TM-4-1-100), the distance between chucks is 5c.
m, each sample piece is stretched in the width direction at a pulling speed of 10 cm / min, and when the elongation rate becomes 50% (when the distance between chucks becomes 5 × 1.5 cm) or when it becomes 100% (At the time when the distance between the chucks becomes 5 × 2 cm), the pulling is stopped. Thereafter, each sample is removed from the tensile tester and allowed to stand, and the length Lcm between chucks of each sample after contraction of each sample is measured. Then, the elongation recovery rate (%) when elongating by 50% is [(5 × 1.5-L)
/(5×1.5-5)]×100. Also,
The elongation recovery rate (%) at 100% elongation is [(5 × 2
−L) / (5 × 2-5)] × 100.

The porosity of the stretchable mixed nonwoven fabric according to the present invention is preferably 85% or more, and most preferably 90% or more. INDUSTRIAL APPLICABILITY The present invention makes it possible to obtain a stretchable mixed nonwoven fabric without substantially reducing the porosity. For example, it is possible to obtain a fiber fleece (a fiber aggregate as a precursor for obtaining a stretchable mixed nonwoven fabric). Even if the porosity is less than 85%, the resulting stretchable mixed nonwoven fabric has a porosity of 85% or more. The porosity of the stretch-mixed nonwoven fabric is 85
%, The size of the voids formed between the long fibers is too small, and tends to be unsuitable for general use. For example, when the stretchable mixed nonwoven fabric is used as a medical hygiene material, sweat and the like tend to accumulate and become humid, and the body fluid permeability tends to be poor. Porosity of stretch mixed nonwoven fabric (%)
Is calculated by the formula [1- (w / tSρ)] × 100 (%). Here, S is the area of the nonwoven fabric (cm
² ), t represents the thickness (cm) of the nonwoven fabric, and ρ represents the weight average density (g / cm) of the two types of long fibers constituting the nonwoven fabric.
³ ), and w represents the weight (g / cm ² ) of the nonwoven fabric having the area S. The thickness was measured by applying a load of 4.5 g / cm ^{2 to} the nonwoven fabric. The weight average density (g / cm ³ )
｛[Density of high-melting polyester long fiber × weight ratio of high-melting polyester long fiber (% by weight)] + [density of low-melting polyester long fiber × weight ratio of low-melting polyester long fiber (% by weight)] It is calculated by the formula of｝ / 100.

The tensile strength of the stretchable mixed nonwoven fabric is preferably 35 kg / 5 cm or more in the longitudinal direction. If the tensile strength is lower than this value, the nonwoven fabric may be broken when used in an application to which a relatively large external force is applied. The method for measuring the tensile strength is the same as the method for measuring the elongation at break, which is a value obtained by measuring the load when the sample piece breaks and converting the average value to a basis weight of 100 g / m ² .

The total hand value of the stretchable mixed nonwoven fabric according to the present invention is preferably 2.5 g / g / m ² or less, and most preferably 2.0 g / g / m ² or less. preferable. If the total hand value exceeds 2.5 g / g / m ² , a stretchable mixed nonwoven fabric lacking in flexibility is obtained. In particular, when the stretchable mixed nonwoven fabric according to the present invention is used for medical hygiene materials applied to the human body, a flexible material having a total hand value of 2.5 g / g / m ² or less is used. Is preferred. Total hand value is JIS
It is a value obtained by dividing the value measured according to the method described in L-1096 of the handle ometer method by the basis weight.

The stretchable mixed nonwoven fabric according to the present invention can be manufactured by the following method. First, a high-melting polyester polymer and a low-melting polyester polymer are prepared. These two types of polymers are charged into separate melting devices, respectively, and are introduced into a spinneret in a molten state. The spinneret is provided with a plurality of spinning holes, and a high-melting polyester polymer melted into a certain number of the spinning holes is introduced into the spinning holes, and a low-melting polyester polymer melted into other spinning holes. Coalescence is introduced. Then, from one spinneret, a high melting polyester long fiber and a low melting polyester long fiber are simultaneously spun. Further, for a fixed number of spinnerets among a plurality of spinnerets, only high-melting polyester filaments may be spun, and for other spinnerets, only low-melting polyester filaments may be spun. The two kinds of fibers spun by the above method are cooled using a conventionally known cooling device. Next, it is pulled and thinned to the target fineness using the air soccer method or the Docan method. At this time, the towing speed is preferably 3000 m / min or more, and especially 3 m / min.
Most preferably, it is 500 m / min. By such high-speed traction, polyester long fibers having higher crystallinity, higher orientation and higher birefringence than those described in JP-A-2-33369 can be obtained. The breaking elongation of long fibers obtained by such high-speed traction is considerably lower than that described in JP-A-2-33369, and is about 150% or less.

The drawn and thinned high-melting polyester filaments and low-melting polyester filaments are spread by a conventionally known spreading method such as a corona discharge method or a triboelectric charging method, and then moved by a wire mesh. It is deposited on a collecting conveyor such as a screen conveyor to form a fibrous web. When high-melting-point polyester long fibers and low-melting-point polyester long fibers are simultaneously spun from one spinneret and deposited on a collecting conveyor, a fiber web in which both long fibers are relatively uniformly mixed is obtained. . In addition, only high-melting polyester filaments are spun from a certain number of spinnerets, and only low-melting polyester filaments are spun from other spinnerets and deposited on a collection conveyor. In this case, the degree of mixing of the two long fibers becomes more uneven than in the above case. The fiber web thus obtained is partially heated. Then, at a portion where the heat is partially applied, only the low-melting-point polyester long fibers are softened or melted to form a fusion zone where the high-melting-point polyester long fibers are fused to each other. The fusion zones are provided in a scattered manner in the fibrous web, and the fusion zones are arranged at predetermined intervals. Here, the temperature at which the heat is applied to the fibrous web is preferably within a certain range below the melting point of the low-melting polyester long fiber. If this temperature exceeds the melting point of the low-melting polyester continuous fiber, the fusion in the fusion area is severe, and when the fiber fleece is hot-drawn, a hole may be opened in the fusion area. The feel becomes hard. Also, if this temperature is below the melting point of the low-melting polyester filaments and is too low, exceeding a certain range, the fusion between the high-melting polyester filaments is insufficient, and when the fiber fleece is thermally drawn. In addition, there is a possibility that the high-melting-point polyester-based long fibers may come off. In addition, the breaking strength of the obtained nonwoven fabric becomes insufficient. Therefore, the temperature at which heat is applied to the fibrous web is preferably in the range of (the melting point of the low-melting polyester long fiber −5 ° C.) to (the melting point of the low-melting polyester long fiber −30 ° C.).

As a method of partially applying heat to the fibrous web, an embossing device comprising an uneven roll and a smooth roll, or an embossing device comprising a pair of uneven rolls is used, and the uneven roll is heated to give a fiber web. What is necessary is just to press the convex part. In addition, these convex portions are arranged on the uneven roll surface in a scattered manner. At this time, it is preferable that the concavo-convex roll is heated to a temperature within a certain range below the melting point of the sheath component as described above. The shape of the tip surface of each convex portion of the concave-convex roll can be any 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. Also, the fusion zone may be formed using an ultrasonic welding device. The ultrasonic welding device irradiates a predetermined area of the fiber web with ultrasonic waves, and in that area, the frictional heat between the high-melting polyester long fiber and the low-melting polyester long fiber, or the low-melting polyester The heat of friction between the long fibers softens or melts the low melting polyester long fibers.

As described above, after obtaining the fiber fleece in which the heat-fused areas are arranged in a scattered manner, the fiber fleece is expanded in the width direction as desired. This widening can be performed using an apparatus such as an expander roll or a greed gear. The widening is preferably performed under heating, and is preferably performed under an atmosphere in which hot air of 40 to 80 ° C. is blown. This is because by slightly plasticizing the high-melting-point polyester long fibers and the low-melting-point polyester long fibers under heating, it becomes easy to widen at a desired widening ratio. It is preferred that the fiber fleece has a width expansion ratio in the width direction of about 5 to 50%. When the expansion ratio is less than 5%, the basis weight of the nonwoven fabric after the subsequent hot stretching treatment is greatly increased, and it becomes difficult to obtain a low-weight nonwoven fabric. However, when it is not necessary to increase the stretching ratio, it goes without saying that the widening ratio may be less than 5%, and furthermore, the widening may not be performed. If the width ratio exceeds 50%, the fiber fleece may be broken. In addition, the expansion rate (%) of the fiber fleece is represented by {[(width after widening)-(width before widening)] / width before widening} × 100.

Next, the expanded fiber fleece is subjected to hot stretching in the longitudinal direction of the fiber fleece while maintaining the state. The stretching is performed by a known method, for example, between a supply roll and a stretching roll rotating at a higher peripheral speed than the supply roll. This drawing is also performed under heating, and it is preferable to perform the drawing under heating at a temperature equal to or lower than the melting point of the low-melting polyester long fiber. A preferred embodiment of the hot stretching, which also serves as the heat setting, is as follows. The heating temperature of the roll and the like at this time is set to an arbitrary temperature depending on the melting points of the high-melting polyester long fibers and the low-melting polyester long fibers. Therefore, it should be recognized that the heating temperature of the roll and the like in the method described below is only a rough guide.

(I) A method using a supply roll heated to about 60 to 110 ° C. and a stretching roll heated to a temperature about 10 to 30 ° C. higher than the supply roll. In this method, when the fiber fleece is drawn out from the supply roll, hot drawing is performed. Then, when this fiber fleece is introduced into a drawing roll, heat setting is performed. In this case, a heating zone may be provided between the supply roll and the stretching roll. The heating zone is preferably heated to a temperature approximately intermediate between the heating temperature of the supply roll and the heating temperature of the stretching roll. Further, the heating zone may be provided not in the space between the supply roll and the stretching roll but in the process after passing through the stretching roll to further advance the heat setting of each long fiber. The heating zone only needs to heat the fiber fleece, and any means such as dry heat or wet heat is employed. For example, as the dry heat, heating by an oven, heating by infrared rays, heating by contacting with a heat plate, or the like is preferable, and as the wet heat, it is preferable to pass the fiber fleece through hot water or moist heat steam.

(Ii) Supply roll at normal temperature, 70-170
A method using a stretching roll heated to about ° C and a heating zone provided between the supply roll and the stretching roll and heated at a temperature lower than the heating temperature of the stretching roll can be used. In this method, hot drawing is performed when the fiber fleece passes through the heating zone. Then, when this fiber fleece is introduced into a drawing roll, heat setting is performed. As for the heating zone, various means can be adopted as in the case of (i) described above.

(Iii) The heating temperature of the supply roll heated to about 60 to 110 ° C., the stretching roll at room temperature, and the heating temperature of the supply roll installed behind the stretching roll is 10 to 30 ° C.
A method using a heating zone heated to a higher temperature as described above may be used. In this method, when the fiber fleece is drawn out from the supply roll, hot drawing is performed. Then, the fiber fleece is introduced into a drawing roll at room temperature, and then heat-fixed when passing through a heating zone provided behind. The heating zone is described in (i) above.
As in the case of the above, various means can be adopted.

(Iv) A supply roll at room temperature, a stretching roll at room temperature, a first heating zone A provided between the supply roll and the stretching roll, and a second heating zone installed behind the stretching roll. And a method using Part B. The heating zone B is heated at a higher temperature than the heating zone A. Generally, the temperature of the heating zone A is preferably about 60 to 110 ° C., and the temperature of the heating zone B is preferably higher than the temperature of the heating zone A by 10 to 30 ° C. or more. In this method, hot drawing is performed when the fiber fleece passes through the heating zone A. Then, the fiber fleece is introduced into a drawing roll at room temperature, and then heat-fixed when passing through a heating zone B provided behind. As for the heating zones A and B, various means can be adopted as in the case of (i) described above.

The high-melting-point polyester long fiber and the low-melting-point polyester long fiber are plasticized by such thermal drawing, and the drawing by shear deformation is applied to both long fibers. Further, while maintaining a certain degree of fusion between the high-melting polyester filaments in the fusion zone (the low-melting polyester filaments function as an adhesive component in the fusion zone, and are fused together to form a film. Therefore, the low-melting-point polyester long fibers are fixed in this fused area.), And the high-melting-point polyester long fibers and the low-melting-point polyester long fibers in the fiber fleece are re-machined in the machine direction. By being arranged and the molecular orientation in each long fiber constituting the fiber fleece being enhanced, elasticity in the width direction is developed.

The degree of hot stretching is required to be 10 to 80% of the elongation at break of the fiber fleece in the longitudinal direction, and preferably about 40 to 75%. . Here, the stretching ratio means the ratio of the elongation at the time of stretching to the elongation at break in the machine direction of the fiber fleece expressed as a percentage. Therefore, assuming that the elongation at break of the fiber fleece in the longitudinal direction is B%, (0.1 ×
B to 0.8 × B)%, which means that the fiber fleece is stretched in the longitudinal direction. When the stretching ratio is less than 10%, the long fibers in the fiber fleece do not rearrange sufficiently in the machine direction, so that the stretchability in the width direction becomes insufficient. Also,
Since sufficient shear deformation is not given to each long fiber and molecular orientation does not proceed, it is difficult to improve tensile strength. On the other hand, if the stretching ratio exceeds 80%, the stretching is too large, and each long fiber in the fiber fleece may be broken. The elongation at break (%) in the longitudinal direction of the fiber fleece was determined according to JIS-L-1.
According to the method described in No. 096A, it is measured in the same manner as in the case of measuring the breaking elongation of the nonwoven fabric described above.

The heat-drawn fiber fleece is subjected to a heat treatment at a temperature equal to or lower than the melting point of the low-melting polyester long fiber, and is heat-fixed. The temperature for heat setting is preferably higher than the temperature employed during stretching in order to eliminate the thermal history during stretching. This heat setting can also be performed by dry heat or wet heat. In addition, the heat setting may be performed by relaxing the fiber fleece, or may be performed with tension or fixed length. In particular, it is preferable to carry out the stretching with a tension or a fixed length because good stretchability can be imparted to the obtained nonwoven fabric. Such heat setting can be performed by the above-mentioned means (i) to (iv).

FIG. 1 is a flowchart showing a method for producing a stretchable mixed nonwoven fabric according to the present invention. That is, after obtaining a fiber fleece by a predetermined method (step 1), the fiber fleece is expanded under heating (step 2). Next, the fiber fleece in the widened state is thermally drawn under heating (step 3). After the heat stretching, heat setting is performed under heating (step 4). Then, the obtained nonwoven fabric may be wound up as desired (step 5). Each of these steps is typically performed continuously online.
However, the step of obtaining the fiber fleece by separating Step 1 and Step 2 and subsequent steps, and the steps of widening, drawing, and heat setting after Step 2 may be performed in separate steps. In the method for producing a stretchable mixed nonwoven fabric according to the present invention, the porosity of the obtained stretchable mixed nonwoven fabric is greater than the porosity of the fiber fleece, as suggested by the description in Examples below. It is common for it to be large. Such a phenomenon is the reverse of the description in U.S. Pat. No. 5,244,482 relating to the stretched nonwoven fabric and is completely unexpected. The reason why such a phenomenon occurs is not clear, but two kinds of long fibers were used as constituent fibers, a fiber fleece in which the fusion zones were arranged in a scattered manner was used, and heat drawing was performed. It is presumed that this is because the widening process has been performed as desired before. That is, as in the present invention, when there are two types of long fibers, a high-melting polyester long fiber and a low-melting polyester long fiber, in the fiber fleece, when the fiber fleece is hot-drawn, the former long fiber and the latter long fiber are used. Since the thermal behavior is different from that of the long fibers, the applied stress is also different, and it is presumed that slack occurs between the long fibers and voids are generated. Further, since the degree of stretching is substantially different between the scattered fused area and the non-fused area, it is presumed that this difference may further generate voids. Furthermore, when widening before hot stretching,
It is presumed that the gap between the long fibers in the fiber fleece is increased in advance to prevent the gap from decreasing.

The stretchable mixed fiber nonwoven fabric obtained as described above can be used as it is for various conventionally known uses, particularly for use in medical hygiene materials, and as shown in FIG. They can be laminated and used for various purposes. Furthermore, it is used for various applications as a three-layer laminate in which elastic films 2 and 2 are laminated on both sides of elastic mixed nonwoven fabric 1, or elastic composite fibers 1 and 1 are laminated on both surfaces of elastic film 2. You can also. In addition, it is needless to say that the stretchable mixed fiber nonwoven fabric according to the present invention is not limited to such a use form, and may be used in any use form.

[0036]

EXAMPLES The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples. The methods for measuring the physical properties and the like used in the examples are as follows. Measurement of elongation at break (%), elongation recovery rate (%), porosity (%), widening rate (%), tensile strength (kg / 5 cm width) and total hand value (g / g / m ² ) The method is as described above. (1) Melting point (° C.): using a differential device calorimeter DSC-2 manufactured by PerkinElmer, sample weight 5 mg, heating rate 20
The temperature at which the maximum value of the melting endothermic curve was obtained as measured in ° C./min was defined as the melting point. (2) Basis weight (g / m ² ): From the standard sample, 10
After preparing 10 sample pieces of 10 cm × 10 cm in width and adjusting the equilibrium moisture content, the weight (g) of each sample piece is weighed, and the average value of the obtained values is converted into a unit area to obtain a weight per unit area (g / g). m ² ).

Example 1 As a high-melting polyester polymer, polyethylene terephthalate having a melting point of 256 ° C. and an intrinsic viscosity of 0.64 was prepared. On the other hand, as a low-melting polyester polymer, a copolymer having a melting point of 232 ° C. and an intrinsic viscosity of 0.66, ethylene terephthalate as a main repeating unit, and isophthalic acid copolymerized at 8 mol% with respect to all acid components. Polyester was prepared. Each of the two polymers was introduced into a spinneret having a plurality of spinning holes, using separate extruder-type melt extruders. At this time, a high-melting polyester polymer was introduced into half of the spinning holes, and a low-melting polyester polymer was introduced into the other half. Each spinning hole was a circular hole (round hole), and each polymer was melt-spun under the condition of a single hole discharge amount of 1.6 g / min. The yarn group spun from the spinneret is cooled by a known cooling device, and the drawing speed is 4800 m using an air soccer installed below the spinneret.
/ Min. Thereafter, the yarn group was spread by a fiber opening device provided at the outlet of the air soccer, and was deposited on a moving screen conveyor made of wire mesh to obtain a fiber web having a basis weight of 30 g / m ² . At this time, the fineness of the high melting polyester long fibers and the low melting polyester long fibers constituting the fibrous web was 3 denier. The weight ratio of the high melting polyester long fibers to the low melting polyester long fibers in the fibrous web is about 1: 1.
Met.

Next, this fiber web was introduced between a concavo-convex roll heated to 210 ° C. and a smooth roll heated to 210 ° C. As a result, the area of the fibrous web in contact with the convex portion of the concave-convex roll was partially heated, and the high-melting polyester long fibers were fused together by softening or melting the low-melting polyester long fibers. As a result, a fiber fleece in which the fusion zones were arranged in a scattered manner was obtained. The area of each fusion zone was 0.6 mm ² , the density of the fusion zone in the fiber fleece was 20 pieces / cm ² , and the total area of the fusion zone was 15% of the fiber fleece surface area. Was. The elongation at break of this fiber fleece in the longitudinal direction is 5
It was 0%. Further, the weight average density of both long fibers constituting the fiber fleece is 1.295 g / cm ³ ,
The porosity of the fiber fleece was 84.1%.

This fiber fleece was introduced into a pressurized steam processor equipped with a clip tenter, and was expanded by 15% in the width direction in an atmosphere at 80 ° C. Then, in this widened state, the fiber fleece was hot-drawn in the longitudinal direction. As the stretching conditions, a one-stage stretching method was applied, and the film was introduced into a supply roll at a temperature of 90 ° C., and then introduced into a stretch roll at a temperature of 145 ° C., and the stretching ratio was 48.0%. Then, the fiber fleece after the hot drawing was introduced into a heat drum at 220 ° C., and was heat-set to obtain a stretchable mixed fiber nonwoven fabric. Table 1 shows the physical properties of the stretchable mixed nonwoven fabric.

[0040]

[Table 1] In Table 1, the basis weight is the weight (g) per 1 m ² of the nonwoven fabric, EC is the breaking elongation (%) in the width direction of the nonwoven fabric,
EM is the elongation at break (%) of the nonwoven fabric in the longitudinal direction,
(50) is the elongation recovery rate (%) when the nonwoven fabric is stretched 50% in the width direction, and EEC (100) is the elongation recovery rate (%) when the nonwoven fabric is stretched 100% in the width direction. The hand value indicates the flexibility of the nonwoven fabric.

Example 2 A stretchable mixed nonwoven fabric was obtained under the same conditions as in Example 1 except that the stretching ratio was 56.0%. The physical properties are shown in Table 1.

Example 3 An elastic mixed nonwoven fabric was obtained under the same conditions as in Example 1 except that the stretching ratio was 74.0%. The physical properties are shown in Table 1.

Example 4 The polyethylene terephthalate used in Example 1 was prepared as a high melting polyester polymer. On the other hand, as a low-melting polyester polymer, a copolymer having a melting point of 201 ° C. and an intrinsic viscosity of 0.65, ethylene terephthalate as a main repeating unit, and copolymerization of isophthalic acid at 16 mol% with respect to all acid components. Polyester was prepared. Using both polymers, a fibrous web was obtained in the same manner as in Example 1, except that the single hole discharge rate was 1.47 g / min and the drawing speed was 4400 m / min. The basis weight of this fiber web was 30 g / m ² , and the fineness of the high melting polyester long fibers and the low melting polyester long fibers constituting the fibrous web was 3 denier. Further, the weight ratio of the high melting polyester long fibers to the low melting polyester long fibers in the fibrous web was about 1: 1.

The fiber web was provided with a fusion zone in the same manner as in Example 1 except that the temperature of the uneven roll and the smooth roll was set to 180 ° C. The elongation at break in the machine direction of this fiber fleece was 47%. Furthermore,
The weight average density of both long fibers constituting the fiber fleece was 1.290 g / cm ³ , and the porosity of the fiber fleece was 83.9%.

This fiber fleece was introduced into a pressurized steam processor equipped with a clip tenter, and was expanded by 15% in the width direction at 80 ° C. in an atmosphere. Then, in this widened state, the fiber fleece was hot-drawn in the longitudinal direction. As the stretching conditions, a one-stage stretching method was applied, and the film was introduced into a supply roll at a temperature of 80 ° C., and then introduced into a stretch roll at a temperature of 115 ° C., so that the stretching ratio was 55.3%. Then, the fiber fleece after the heat drawing was introduced into a heat drum at 190 ° C., and was heat-set to obtain a stretchable mixed fiber nonwoven fabric. Table 1 shows the physical properties of the stretchable mixed nonwoven fabric.

Example 5 As the high-melting polyester polymer, the copolymer polyester used in Example 1 was prepared. On the other hand, the copolymerized polyester used in Example 4 was prepared as a low-melting polyester polymer. Using both polymers, the single hole discharge amount was set at 1.
A fibrous web was obtained in the same manner as in Example 1, except that the speed was 40 g / min and the drawing speed was 4200 m / min. The basis weight of this fiber web was 30 g / m ² , and the fineness of the high melting polyester long fibers and the low melting polyester long fibers constituting the fibrous web was 3 denier.
Further, the weight ratio of the high-melting polyester long fibers to the low-melting polyester long fibers in the fibrous web is about 1:
It was one.

The fiber web was provided with a fusion zone in the same manner as in Example 4 to produce a fiber fleece. The longitudinal elongation at break of this fiber fleece was 43%. Furthermore,
The weight average density of both long fibers constituting the fiber fleece was 1.285 g / cm ³ , and the porosity of the fiber fleece was 83.6%. Then, the fiber fleece was subjected to hot stretching and heat setting under the same conditions as in Example 4 except that the fiber fleece was widened under the same conditions as in Example 4 and the stretching ratio was set to 55.8%. The physical properties of the stretchable mixed nonwoven fabric obtained as described above were as shown in Table 1.

Comparative Example 1 A non-woven fabric was obtained under the same conditions as in Example 1 except that the basis weight of the fiber web was 40 g / m ² , and the widening, hot stretching and heat fixing were not performed. The physical properties of this nonwoven fabric were as shown in Table 2.

[0049]

[Table 2] In Table 2, each item is the same as in Table 1.

Comparative Example 2 Melt flow rate value at a melting point of 160 ° C. (ASTM D1
238 (L), measured in accordance with the method described in 238 (L)) 30 g / 1
Only 0 minute polypropylene was prepared. Then, this polypropylene alone was introduced into each spinning hole, and the single hole discharge amount was 1.27 g / min, and the drawing speed was 3800 m / min, except that the basis weight was 30 g / m ^{2 in} the same manner as in Example 1. A fibrous web was obtained. This fiber web was composed of 100% by weight of polypropylene filaments, and the fineness of the polypropylene filaments was 3 denier.

A fibrous fleece was prepared by providing a fusion zone in the same manner as in Example 1 except that the temperature of the uneven roll and the smooth roll was 145 ° C. The longitudinal elongation at break of this fiber fleece was 80%. Furthermore,
The density of the polypropylene long fibers constituting the fiber fleece was 0.86 g / cm ³ , and the porosity of the fiber fleece was 73.9%.

This fiber fleece was introduced into a pressurized steam processing machine equipped with a clip tenter, and was widened by 15% in the width direction under an atmosphere of 80 ° C. And in this widened state,
The fiber fleece was hot drawn in the machine direction. As the stretching conditions, a one-stage stretching method is applied, and after introducing into a supply roll at a temperature of 90 ° C., and then into a stretching roll at a temperature of 135 ° C.,
The stretching ratio was 57.5%. Then, the fiber fleece after the heat drawing was introduced into a heat drum at 150 ° C., and was heat-set to obtain a stretchable nonwoven fabric. Table 2 shows the physical properties of this stretchable nonwoven fabric.

As is clear from the results in Table 1, Example 1
Each of the stretchable mixed-fiber nonwoven fabrics obtained by the methods according to Nos. To 5 was excellent in stretchability in the width direction. In general, as the stretching ratio is increased, the extensibility in the width direction is increased, and the elongation recoverability is also increased. on the other hand,
As is clear from the results in Table 2, in the method according to Comparative Example 1, since the hot stretching and the heat setting were not performed, the extensibility and the elongation recovery were insufficient, and it was far from an elastic mixed wire nonwoven fabric. Was something. Further, in the method according to Comparative Example 2, since only the polypropylene long fiber was used alone as the long fiber, as can be seen from the fact that the basis weight was lower than that in Examples 1 to 5, the polypropylene length during the hot stretching was reduced. There is a tendency for the fibers to come off and for the heat setting to be insufficient. In addition, the stretchability and stretch recovery were both insufficient, and were far from stretchable nonwoven fabrics. Furthermore, as is clear from the results in Table 1, the porosity of the stretchable mixed nonwoven fabric obtained by the method according to Examples 1 to 5 is larger than the porosity of the fiber fleece before widening and stretching. You can see that.

[0054]

The stretchable mixed nonwoven fabric according to the present invention comprises high-melting polyester filaments and low-melting polyester filaments, and has a high melting point by softening or melting the low-melting polyester filaments. The fusion zone in which the polyester long fibers are fused to each other is arranged in a scattered manner, and the following four conditions are simultaneously satisfied. That is, (i) the breaking elongation in the width direction of the nonwoven fabric is 150%
(Ii) the ratio of the breaking elongation in the width direction to the breaking elongation in the longitudinal direction of the nonwoven fabric is 5 or more, and (iii) the elongation recovery rate when the nonwoven fabric is stretched by 50% in the width direction is 60. %
That is, (iv) the elongation recovery rate when the nonwoven fabric is stretched by 100% in the width direction is 50% or more. Therefore, it has the effect of exhibiting extremely large elasticity in the width direction and having unidirectional elasticity that hardly exhibits elasticity in the vertical direction. Furthermore, when the porosity of the stretchable mixed-fiber nonwoven fabric according to the present invention is 85% or more, there is an effect of being excellent in water permeability and liquid permeability.

Further, the method for producing a stretchable mixed-fiber nonwoven fabric according to the present invention comprises a high-melting polyester long fiber and a low-melting polyester long fiber, and the softening or melting of the low-melting polyester long fiber. Further, a fiber fleece in which a fusion zone in which high-melting polyester long fibers are fused to each other is arranged in a scattered manner is used, and this is subjected to thermal drawing. Therefore, composed of a kind of long fiber,
As in the case of a fiber fleece having a similar fusion zone, the fusion zone collapses during hot drawing (when the fusion between the long fibers is severe), or the long fibers come off (between the filaments). Is insufficient). That is, in the case of fusion with the low-melting polyester long fiber, since the high-melting polyester long fiber exists in the fusion area while maintaining the fiber form to some extent, the fusion area can be prevented from collapsing. In addition, since the high-melting-point polyester long fibers maintain the fiber form, the low-melting-point polyester long fibers can be sufficiently softened or melted, and insufficient fusion can be prevented.

Further, in the method for producing a stretchable mixed nonwoven fabric according to the present invention, the fiber fleece is expanded in the width direction as desired before the hot stretching, so that the fiber fleece is stretched at a relatively high magnification in the longitudinal direction. Even so, there is an effect that the width of the obtained stretchable mixed nonwoven fabric can be reduced and the weight per unit area can be reduced. In addition, since the obtained stretchable mixed nonwoven fabric can be inevitably stretched up to the width at the time of widening, there is also an effect that high stretchability and stretch recovery can be ensured.

Further, in the method for producing a stretchable mixed nonwoven fabric according to the present invention, heat setting is performed after hot stretching, so that both polyester-based long fibers that have undergone shear deformation during stretching can be stabilized in shape. . Therefore, both polyester long fibers rearranged in the longitudinal direction of the fiber fleece during stretching are stabilized in the rearranged form. Therefore, after the production of the stretch-mixed nonwoven fabric, it has an effect that there is little dimensional change in the longitudinal direction or the width direction, and it is easy to return to the rearranged form when stretched in the width direction, and the stretch recovery property is improved. It also has the effect of excellence.

Further, in the method for producing a stretchable mixed nonwoven fabric according to the present invention, the porosity of the stretchable mixed nonwoven fabric can be made larger than the porosity of the fiber fleece. The reason for this is, as described above, that high-melting polyester long fibers and low-melting polyester long fibers are mixed and used as the constituent fibers, and that the heat-fused areas are provided in the fiber fleece in a scattered manner. This is considered to be due to the fact that the film is subjected to thermal stretching after being subjected to a widening treatment if desired. Therefore, it is possible to obtain a stretchable mixed nonwoven fabric having a relatively large porosity, and it is possible to efficiently obtain a stretchable mixed nonwoven fabric having excellent water permeability and liquid permeability. Therefore, the stretchable mixed-fiber nonwoven fabric according to the present invention or the stretchable mixed-fiber nonwoven fabric obtained by the method according to the present invention can be suitably used particularly for medical hygiene materials.

[Brief description of the drawings]

FIG. 1 is a flowchart showing an example of manufacturing a stretchable mixed fiber nonwoven fabric according to the present invention.

FIG. 2 is a cross-sectional view of a laminate according to an example of use of the stretchable mixed nonwoven fabric according to the present invention.

[Explanation of symbols]

 1 Elastic blended nonwoven fabric 2 Elastic film

Claims (6)

[Claims] 1. A high-melting polyester long fiber and a low-melting polyester long fiber are accumulated in a mixed state, and softening of the low-melting polyester long fiber between the high-melting polyester long fibers. Alternatively, a stretchable mixed-fiber nonwoven fabric characterized in that a fusion zone fused by melting is provided in a scattered manner and simultaneously satisfies the following formulas (1) to (4). EC ≧ 150% (1) EC / EM ≧ 5 (2) EEC (50) ≧ 60% (3) EEC (100) ≧ 50% (4) (However, , EC is the elongation at break in the width direction of the nonwoven fabric, EM
Is the elongation at break in the longitudinal direction of the nonwoven fabric, EEC (50) is the elongation recovery rate when the nonwoven fabric is stretched by 50% in the width direction, and EEC (100) is the stretch recovery rate when the nonwoven fabric is stretched by 100% in the width direction. Elongation recovery rate. ) 2. The high-melting polyester filament and the low-melting polyester filament have a fineness of 15 denier or less, and the high-melting polyester filament and the low-melting polyester filament are different from each other. 2. The stretchable mixed nonwoven fabric according to claim 1, wherein the nonwoven fabric is mixed at a content weight ratio of the long fiber: the low-melting polyester-based long fiber = 1: 0.1 to 5. 5. 3. The stretchable mixed-fiber nonwoven fabric according to claim 1, having a porosity of 85% or more. 4. A high melting point polyester long fiber and a low melting point polyester long fiber are deposited on a collecting conveyor,
A fiber web formed by integrating both fibers in a mixed state is formed, and heat is partially applied to the fiber web, so that the high-melting polyester long fibers soften or soften the low-melting polyester long fibers. After obtaining a fiber fleece in which a fusion zone fused by melting is provided in the fiber web in a scattered manner, the fiber fleece is expanded in the width direction so as to have a width expansion ratio of 0 to 50%. And the fiber fleece in the longitudinal direction is 10
A method for producing a stretchable mixed nonwoven fabric, comprising thermally stretching at a stretching ratio of about 80%, and thereafter heat-setting at a temperature not higher than the melting point of the low-melting polyester fiber. 5. The fiber fleece has a width expansion ratio of 5 to 5 in the width direction.
The method for producing a stretchable mixed nonwoven fabric according to claim 4, which is 0%. 6. The method for producing a stretchable mixed nonwoven fabric according to claim 4, wherein the porosity of the stretchable mixed nonwoven fabric is larger than the porosity of the fiber fleece.