JPH09310261A - Laminated nonwoven fabric and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a laminated nonwoven fabric, excellent in water absorbency and mechanical characteristics and suitable for medical, sanitary materials, etc., by laminating a specific continuous filament nonwoven web to a staple fiber nonwoven web formed of natural fibers, etc., and then fusing both the nonwoven webs. SOLUTION: This laminated nonwoven fabric is obtained by melt spinning an alternately laminated type conjugated continuous filament yarn from a high-melting component A comprising the first aliphatic polyester having the biodegradability and a low-melting component B comprising the second aliphatic polyester having the lower melting point than that of the high-melting component A and the biodegradability such that the respective plural high-melting components A and low-melting components B are alternately laminated in the filament cross section, continued in the filament axial direction and exposed to the filament surface, drawing and attenuating the resultant alternately laminated conjugated continuous filament yarn, then forming a continuous filament nonwoven web, laminating a staple fiber nonwoven web formed of natural fibers and/or regenerated fibers to the resultant continuous filament nonwoven web, subsequently carrying out the ultrasonic fusion treatment, partially fusing both the nonwoven webs and integrating both the webs.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a medical / hygiene material,
The present invention relates to a laminated non-woven fabric suitable for a wide range of applications where biodegradability is required, such as daily life materials and general industrial materials, and a manufacturing method thereof.

[0002]

2. Description of the Related Art As a biodegradable nonwoven fabric, there is known a biodegradable nonwoven fabric derived from natural fibers such as cotton, hemp, wool, rayon, chitin and alginic acid. However, although these biodegradable non-woven fabrics are generally hydrophilic and have excellent water absorption, on the other hand, these non-woven fabrics show a remarkable decrease in strength and dimensional stability in a wet environment. There was a limit to the development of the department. further,
Since these non-woven fabrics are non-thermoplastic, they have no thermoformability and are inferior in processability.

As a biodegradable non-woven fabric which solves these problems, Japanese Patent Laid-Open Publication No. 93933/1993 or Japanese Laid-Open Patent Publication No.
Japanese Patent No. 195407 discloses a non-woven fabric using a biodegradable thermoplastic polymer. However, in these, the spunbond method is difficult to produce because the spun yarn has poor cooling properties, spinnability and fiber-spreadability, and since it is a fully melted type, the mechanical properties of the resulting nonwoven fabric and It was inferior in flexibility. This is because the melting point and crystallization temperature of the biodegradable polymer are generally low and the crystallization rate is slow. That is, in the cooling, traction thinning, collection, and deposition steps after melt spinning, sufficient opening cannot be performed because adhesion occurs between yarns, and the texture of the resulting nonwoven fabric is impaired. This will cause problems.

Further, the above-mentioned nonwoven fabric formed of long fibers alone composed of a biodegradable thermoplastic polymer has excellent mechanical properties, but is poor in hygroscopicity and water absorption, and its use is limited. Met. As a method for improving this, it is conceivable to laminate natural fibers and the like having excellent water absorption, but to laminate a long fiber nonwoven web made of a biodegradable thermoplastic polymer and a nonwoven web made of natural fibers. In the case of performing partial heat fusion by means of a heat-pressure welding apparatus using an embossing roll which has been conventionally applied, the adhesive force between the two webs is weak and the obtained laminated nonwoven fabric cannot withstand use at all.

[0005]

SUMMARY OF THE INVENTION The present invention solves such a problem and has excellent cooling and opening properties of spun yarns, has biodegradability and is highly water-absorbent, and is practically used. The present invention is intended to provide a laminated nonwoven fabric having mechanical properties sufficient for use in the above and a method for producing the same.

[0006]

To solve this problem, the present invention has the following structures. (1) A long-fiber non-woven web and a short-fiber non-woven web are laminated and integrated by partial heat pressing, and the long-fiber non-woven web is composed of a first aliphatic polyester having biodegradability. An alternating laminated composite continuous fiber comprising an alternating laminated composite filament formed from a high melting component and a low melting component composed of a second aliphatic polyester having a lower melting point than the high melting component and having biodegradability. The high melting point component and the low melting point component are alternately laminated in the cross section of the fiber, and the high melting point component and the low melting point component are continuous in the fiber axis direction and are exposed on the fiber surface. A laminated non-woven fabric, characterized in that the woven web contains at least natural fibers or recycled fibers.

(2) A high melting point component composed of a first aliphatic polyester having biodegradability and a low melting point component composed of a second aliphatic polyester having a biodegradability lower than the high melting point component. Alternating lamination type in which a plurality of high melting point components and low melting point components are alternately laminated in the cross section of the fiber, and the high melting point component and the low melting point component are continuous in the fiber axis direction and exposed on the fiber surface. After the composite long fibers are melt-spun and the alternating laminated type composite long fibers are towed and thinned to form a long-fiber non-woven web, the long-fiber non-woven web is formed into a short-fiber non-woven fabric formed from natural fibers and / or recycled fibers. A method for producing a laminated non-woven fabric, which comprises laminating woven webs and then subjecting them to ultrasonic fusion treatment to partially fuse and integrate both non-woven webs.

(3) A high melting point component made of a first aliphatic polyester having biodegradability and a low melting point component made of a second aliphatic polyester having a lower melting point than the high melting point component. Alternating lamination type in which a plurality of high melting point components and low melting point components are alternately laminated in the cross section of the fiber, and the high melting point component and the low melting point component are continuous in the fiber axis direction and exposed on the fiber surface. After the composite long fibers are melt-spun and the alternating laminated type composite long fibers are towed and thinned to form a long-fiber non-woven web, the long-fiber non-woven web is provided with natural and / or regenerated fibers and biodegradability. After laminating a short fiber non-woven web formed by mixing short fibers made of a thermoplastic polymer, the laminated non-woven fabric is characterized in that the two non-woven webs are integrated by partially subjecting them to a heat pressing treatment. Manufacturing method.

According to the present invention, since at least a natural fiber or a regenerated fiber is present as a constituent fiber of the short fiber non-woven web, the natural fiber or the regenerated fiber exerts water absorption and mechanical strength when wet. The disadvantage of inferior natural or recycled fibers can be reinforced by long-fiber nonwoven webs.

In the laminated non-woven fabric of the present invention, the long fiber non-woven web is composed of an aliphatic polyester polymer, and the short fiber non-woven web is made of natural or natural material such as cotton or rayon.
Since it is composed of recycled fibers or short fibers having biodegradability, and all the constituent materials can be decomposed in a natural environment, they can exhibit excellent biodegradability.

Further, according to the present invention, a plurality of high-melting-point components and low-melting-point components are arranged alternately in the fiber cross section of the long fibers constituting the long-fiber nonwoven web. Moreover, since the high-melting point component and the low-melting point component are continuous in the fiber axis direction and exposed on the fiber surface, the low-melting point component, which is inferior in biodegradability but excellent in cooling and opening properties, is subdivided. can do. This makes it possible to obtain a nonwoven fabric that is excellent in cooling properties, fiber-opening properties, and biodegradability.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The laminated nonwoven fabric of the present invention comprises a long fiber nonwoven web and a short fiber nonwoven web which are laminated and integrated.

First, the long-fiber non-woven web according to the present invention will be described. The long fibers constituting the long-fiber non-woven web are two kinds of biodegradable aliphatic polyesters having different melting points,
That is, it is a composite long fiber composed of an aliphatic polyester having a high melting point and an aliphatic polyester having a low melting point.

In the present invention, examples of the aliphatic polyester constituting the long-fiber nonwoven web include poly (α-hydroxy acid) such as polyglycolic acid and polylactic acid,
Alternatively, a poly (ω-hydroxyalkanoate) such as poly (ε-caprolactone), poly (β-propiolactone), or a copolymer of repeating unit elements constituting them may further be added to poly-3-hydroxypropanoate. Pionate, poly-3-hydroxybutyrate, poly-3-
Poly (β-hydroxyalkanoates) such as hydroxycaproate, poly-3-hydroxyheptanoate, and poly-3-hydroxyoctanoate, and the repeating unit elements and poly-3-hydroxyvalerates constituting these, Examples thereof include a copolymer with a repeating unit element constituting poly-4-hydroxybutyrate. In addition, as a polycondensate of diol and dicarboxylic acid,
For example, polyethylene oxalate, polyethylene succinate, polyethylene adipate, polyethylene azetate, polybutylene oxalate, polybutylene succinate, polybutylene adipate, polybutylene sebacate, polyhexamethylene sebacate, polyneopentyl oxalate or these Examples thereof include copolymers composed of repeating unit elements. Among the above aliphatic polyesters, polylactic acid, polyethylene succinate, polybutylene succinate, polybutylene adipate, polybutylene sebacate, or a copolymer of repeating unit elements constituting these is effective in improving spinnability and biodegradability. It is preferably used because it is excellent.

Further, among the above-mentioned aliphatic polyesters, a copolymerized polyester having butylene succinate as a main repeating unit is particularly suitable, but the copolymerization amount ratio of butylene succinate at this time is as a high melting point component. 8
It is preferable that 0 mol% or more, and the low melting point component is 70 to 90 mol%. If the copolymerization amount ratio of butylene succinate is too low, the biodegradability is excellent, but the cooling properties and fiber-opening properties of the spun yarn are poor, and the intended long fibers cannot be obtained. On the other hand, when the copolymerization amount ratio of butylene succinate is too high, the cooling property and the fiber-opening property are excellent, but the biodegradability is inferior and it is not the object of the present invention.

The aliphatic polyester used in the present invention has a number average molecular weight of about 20,000 or more, preferably 40,000 or more, more preferably 60,0.
Those having a value of 00 or more are good in terms of the spinnability and the characteristics of the obtained yarn. Further, it may be chain-extended with a small amount of diisocyanate or tetracarboxylic dianhydride in order to increase the degree of polymerization.

Regarding the fiber applied in the present invention, it is preferable that a crystal nucleating agent is added to at least the low melting point component of the constituent components. By adding the crystal nucleating agent, it is possible to prevent adhesion between spun yarns even if the polymer has low crystallinity and is hard to solidify after melt spinning. The crystal nucleating agent is added in the polymerization step or the melting step. At this time, it is preferable to disperse the nucleating agent as uniformly as possible in order to improve the mechanical performance and the uniformity of the obtained yarn.

The crystal nucleating agent is not particularly limited as long as it is a powdered inorganic substance and does not dissolve in the melt, but talc, calcium carbonate, titanium oxide, boron nitride, silica gel, magnesium oxide and the like. Is usually used, and among these, talc, titanium oxide, or a mixture thereof is preferably used.

Regarding the crystal nucleating agent, the addition amount of the crystal nucleating agent to the high melting point component was QA (wt%), and the addition amount of the crystal nucleating agent to the low melting point component was QB (wt%). sometimes,
It is preferable that it is added so as to satisfy the formulas (1) and (2). [(ΔTA + ΔTB) / 100] −2 / 3 ≦ QA + QB ≦ [(ΔTA + ΔTB) / 100] +4 (1) QA ≦ QB (2) where ΔTA = melting point of high melting point component−high melting point component Crystallization temperature ΔTB = melting point of low melting point component-crystallization temperature of low melting point component When the total amount of crystal nucleating agent QA + QB (% by weight) exceeds the upper limit defined by the formula (1), Although it has a high cooling effect, it is not preferable because the long fiber non-woven web obtained is inferior in mechanical performance as the spinnability is lowered. On the contrary, when the total amount of the crystal nucleating agent QA + QB (wt%) becomes lower than the lower limit defined by the formula (1), the cooling property of the spun yarn is deteriorated and the spun yarn is adhered. However, it becomes difficult to obtain the target long-fiber non-woven web. Also, when the addition amount QA (% by weight) of the nucleating agent in the high melting point component is larger than the addition amount QB (% by weight) of the nucleating agent in the low melting point component, the cooling property of the high melting point component is reduced. Although it is further improved, the cooling property of the low-melting point component is lowered, and this is not preferable because adhesion between spun yarns is likely to occur.

In the present invention, the high melting point component or the low melting point component, or both of them may be added as necessary.
For example, various additives such as matting agents, pigments, light stabilizers, weathering agents and antioxidants can be added within a range that does not impair the effects of the present invention.

Next, the fiber cross-section of the composite long fibers constituting the long-fiber non-woven web must be an alternating laminated composite cross-section. In the alternate lamination type composite section of the present invention, a plurality of high-melting point components and low-melting point components are alternately laminated in the cross section of the fiber, and the high melting point component and the low melting point component are continuous in the fiber axis direction and the fiber surface. Must be exposed. By respectively laminating a plurality of high melting point components and low melting point components, for example, even if the low melting point component is a polymer inferior in cooling properties and openability,
Adjacent high-melting-point components can improve the cooling property and spreadability of the spun yarn. Further, even if the high melting point component is a polymer having poor biodegradability, the adjacent low melting point component is excellent in biodegradability, so when the low melting point component decomposes over time, the high melting point component remains as a thin piece with a very small fineness. The resulting non-woven fabric has excellent biodegradability. Further, it is necessary that both the high melting point component and the low melting point component are continuous in the fiber axis direction in order to enhance the stability of the fiber cross section, the spinning property, and the mechanical properties of the fiber. Further, it is necessary that both of the above-mentioned components are exposed on the fiber surface in order to improve the cooling property and fiber-opening property of the spun yarn and to promote and control the biodegradability.

In the present invention, the cross-sectional shape of the fiber is not particularly limited, and may be a hollow cross section or a multilobe cross section in addition to the usual round cross section. By making the cross-sectional shape of the fiber different, it is possible to further improve the cooling property of the spun yarn, the openability, and the biodegradability of the nonwoven fabric, which are the objects of the present invention.

In the fiber cross section of the composite continuous fiber applied to the present invention, the total number of laminated layers of the high melting point component and the low melting point component is 4 or more, and the single yarn fineness of the composite continuous fiber is 1.5 to.
It is preferably 10 denier. The total number of layers is 4
If it is less than the above range, the spinnability of the spun yarn is inferior in cooling property, fiber-opening property and biodegradability. That is, in the layer-by-layer composite cross section of the present invention, the larger the individual layers are, the poorer the cooling property, the fiber-opening property and the biodegradability of the spun yarn are. Moreover, it is necessary to control the total number of laminated layers based on the fineness of the composite long fibers. That is, in the case of a fineness such as 1.5 denier, if the total number of laminated layers is too large, not only the cross-sectional shape becomes unstable during the yarn making process but also yarn breakage easily occurs, which is not preferable. vice versa,
In the case of a large fineness such as 10 denier, if the total number of laminated layers is too small, the spun yarn is inferior in cooling property and openability, and further, since pieces of each component are large, biodegradability is inferior. Will result. For this reason, the total number of stacked layers is 4 to
More preferably, it is 16. The size of the laminated pieces may be individually different. In addition, when the single yarn fineness of the composite long fibers is less than 1.5 denier, the resin flow in the spinneret becomes unstable, the yarn breakage occurs frequently in the spinning process, the production amount decreases, and the fiber cross-sectional shape becomes unstable. And so on, which is not preferable. On the other hand, if it exceeds 10 denier, the spun yarn has poor cooling properties and biodegradability. For this reason, it is more preferable that the single yarn fineness is 2 denier to 8 denier.

The composite long fibers applied to the present invention have a high melting point component / low melting point component composite ratio of 1/3 to 3/1 (weight ratio).
It is preferred that When the composite ratio is out of this range, it is not possible to satisfy all of the cooling property, the fiber-opening property and the biodegradability of the spun yarn, and furthermore, the instability of the fiber cross-sectional shape is induced, which is preferable. Absent. For example, when the composite ratio of the high-melting-point component / low-melting-point component exceeds 1/3, the resulting biodegradability is excellent, but the cooling property and the opening property of the spun yarn are poor. Conversely, when the composite ratio of the high melting point component / the low melting point component exceeds 3/1, the spun yarn is excellent in the cooling property and the spreadability, but is inferior in the biodegradability. Further, for example, if the high melting point component is a polymer having poor biodegradability,
The biodegradation rate can be accelerated by increasing the composite ratio of the low melting point component. For this reason, it is more preferably 1 / 2.5-2.5 / 1 (weight ratio).

Next, the short fiber non-woven web of the present invention will be described. The short fiber nonwoven web applied to the present invention is formed by containing at least natural fibers or recycled fibers. Thereby, in the present invention, excellent water absorption can be exhibited.

Examples of natural or regenerated fibers include cellulosic fibers such as cotton fibers and hemp fibers, animal fibers such as ramie, silk fibers cut into short fibers, and the like.
Examples include various regenerated fibers such as natural pulp and rayon, and in view of water absorbency, hygroscopicity, raw material cost, etc., cotton fiber is particularly preferably used. Also,
These natural fibers may be in any form such as a combed yarn that has not been bleached, a bleached cotton that has been bleached, or a fluff obtained from a woven or knitted fabric.

In the present invention, the natural fiber and / or
Alternatively, a short-fiber nonwoven web may be formed only from recycled fibers, but a short-fiber nonwoven web is obtained by mixing short fibers made of a thermoplastic polymer having biodegradability with natural fibers and / or recycled fibers. It can also be formed. As described above, by incorporating fibers having thermoplasticity into the short fiber non-woven web, as a means for laminating and integrating the short fiber non-woven web and the long fiber non-woven web, partial hot pressing by a hot embossing roll is performed. The device can be used. That is, when the short fiber non-woven web is composed only of natural fibers or / regenerated fibers, only the constituent fibers of the long fiber non-woven web are melted by heat, so that it is difficult to firmly integrate the short fiber non-woven web. At the time of integration, it is necessary to apply an ultrasonic fusing device capable of generating heat even inside the long fiber nonwoven web and the short fiber nonwoven web in contact with each other.
On the other hand, when a fiber having thermoplasticity is mixed into the short fiber non-woven web, the constituent fibers of the long fiber non-woven web and the short fiber non-woven web are melted by heat, so that the hot embossing roll is used. Alternatively, regardless of the application of ultrasonic waves, the long-fiber nonwoven web and the short-fiber nonwoven web can be integrated with an adhesive force sufficient for practical use.

When a short fiber non-woven web is formed by mixing short fibers made of a thermoplastic polymer having a biodegradability with natural fibers and / or recycled fibers, a plurality of mixed short fibers are used. However, it is preferable that they are mixed as uniformly as possible. By using the uniformly mixed short fiber non-woven web, the thermoplastic short fibers in the short fiber non-woven web and the constituent long fibers of the long fiber non-woven web can be uniformly heat-pressed to obtain It is possible to impart evenly excellent mechanical strength to the laminated nonwoven fabric.

When the short-fiber nonwoven web is formed by mixing natural fibers and / or recycled fibers with short fibers made of a thermoplastic polymer having biodegradability, all the constituent fibers of the short-fiber nonwoven web. On the other hand, it is preferable that 30 to 70% by weight of natural fibers and / or recycled fibers are contained in the short fiber nonwoven web. If the content of natural fibers and / or recycled fibers is less than 30% by weight, the water absorbency of the resulting nonwoven fabric will decrease. Conversely, if the content of natural fibers and / or recycled fibers exceeds 70% by weight, short fiber non-woven fabrics will be obtained. Since the amount of short fibers made of a polymer having thermal adhesiveness in the web is small, the long-fiber nonwoven web and the short-fiber nonwoven web are insufficiently integrated, resulting in a non-practical nonwoven fabric.

In the present invention, the short fibers forming the short fiber non-woven web together with the natural fibers and / or the regenerated fibers are those having biodegradability and thermoplasticity. As long as it has a melting point within a range capable of thermal bonding with the aliphatic polyester constituting the
It can be used regardless of the cross-sectional shape of the fiber or the composite shape. In particular, short fibers containing at least a low melting point component among the components constituting the long fiber non-woven web are preferable in terms of adhesiveness to the long fiber non-woven web. As described above, in the present invention, by incorporating the short fibers having biodegradability and thermoplasticity in the short fiber non-woven web, the long fiber non-woven web and the short fiber non-woven web are sufficiently strong by hot pressing. Can be glued with.

The short-fiber non-woven web according to the present invention is a parallel web arranged in the traveling direction of the card machine, a cross-laid web of parallel webs, a randomly arranged random web, or a semi-random web arranged in a medium degree. It may be any of the above, and can be appropriately selected depending on the intended use.

In the present invention, the laminating ratio of the long fiber non-woven web and the short fiber non-woven web is 10/90 to 90/10.
(% By weight) is preferable. When the short fiber non-woven web is less than 10% by weight, the amount of natural fibers and recycled fibers contained in the laminated non-woven fabric is small, and although the resulting non-woven fabric has excellent mechanical properties, it has sufficient hygroscopicity and water absorption. It is not preferable because it cannot be improved and the object of the present invention cannot be achieved. Conversely, a short fiber non-woven web is 9
If it exceeds 0% by weight, the hygroscopicity and the water absorption are excellent, but the mechanical properties are impaired, which is not preferable. For these reasons, the lamination ratio of the long fiber nonwoven web and the short fiber nonwoven web is more preferably 20/80 to 80/20 (% by weight).

Integration of the laminated long-fiber non-woven web and the short-fiber non-woven web is carried out by partial hot-pressing. This partial heat-pressure welding is performed by using an ultrasonic fusing device as described above, or a device using a hot embossing roll when the short-fiber nonwoven web contains thermoplastic short fibers. A fused area is formed.

Next, the method for producing the laminated nonwoven fabric of the present invention will be described. First, the production of the long-fiber non-woven web applied to the present invention can be carried out by using an ordinary composite spinning device. First, the aliphatic polyester having biodegradability as described above, that is, polybutylene succinate as a high melting point component and butylene succinate having a copolymerization amount ratio of butylene succinate of 70 to 90 mol% as a low melting point component is mainly repeated. Copolymerized polyester as a unit is melted separately as a suitable material, and individually weighed so that the composite ratio of the high melting point component / low melting point component is 1/3 to 3/1 (weight ratio). Number of each segment of both components of
A spun yarn is discharged from a composite spinneret capable of forming a cross-sectional structure of fibers of alternating lamination type that satisfies the single yarn fineness.

FIG. 1 is a schematic view of a spinneret for obtaining such alternate laminated composite long fibers. Here, reference numeral 1 denotes an intermediate plate having an introduction hole 2 for a high melting point component and an introduction hole 3 for a low melting point component. Reference numeral 4 denotes a base. The base 4 joins the high-melting-point component and the low-melting-point component discharged from the introduction holes 2 and 3 at the portion 5 to form a composite flow. Then, the bonded composite flow is introduced into the guide hole 7 in which the stationary kneading element 6 is provided, and is spun from the discharge hole 8 as an alternately laminated composite flow. The number of laminated layers in the fiber cross section of the obtained long fiber is determined by the number of static kneading elements 6. The spinneret for obtaining the alternately laminated composite long fibers is not limited to such a structure.

FIGS. 2, 3 and 4 exemplify the cross-sectional structure of the alternate laminated type composite filaments according to the present invention. Here, A indicates a high melting point component, and B indicates a low melting point component.

The spun fiber is cooled by a known cooling device. Then, it is pulled and thinned by an air soccer so as to have a target fineness, and is taken. The traction-thinned composite long fibers are opened by a known opening device, and then spread and deposited on a movable collecting surface such as a screen conveyor to obtain a long fiber non-woven web.

In the method for producing a laminated nonwoven fabric of the present invention, the above-mentioned crystal nucleating agent is added to the polymer used, particularly the polymer constituting the low melting point component, to prevent the spun yarn from adhering and to cool it. And the spreadability can be improved.

In the melt spinning, the spinning temperature varies depending on the aliphatic polyester used, but can be appropriately set in consideration of at least the MFR value of the polymer and the fiber-forming property, that is, the spinnability. Usually, the spinning temperature is at least 40 ° C. above the melting point of the polymer, especially 1
The temperature is preferably 20 to 300 ° C. Spinning temperature is 120
If the temperature is less than 0 ° C, unmelted matter is generated, or the melt viscosity of the polymer is too high, making it difficult to extrude the polymer using a melt extruder, and conversely, if the spinning temperature exceeds 300 ° C. However, both of them are not preferable because the polymer begins to undergo thermal decomposition.

For traction refinement, traction speed is 2000
It is preferably m / min or more, and more preferably 2500 m / min or more because the dimensional stability of the nonwoven fabric is improved. If the traction speed is less than 2000 m / min,
Since the orientation of the yarns is insufficient, the yarns adhere to each other and the openability is deteriorated, so that the target non-woven fabric cannot be obtained.

Next, a method for manufacturing the short fiber non-woven web in the present invention will be described. When the short fiber non-woven web is composed only of natural fibers and / or recycled fibers, ordinary natural fibers and / or recycled fibers obtained by a conventional method are mixed singly or in plural, and then carded by a card machine. A non-woven fiber web. On the other hand, when the short fiber non-woven web is composed of natural fibers and / or regenerated fibers and short fibers made of a biodegradable thermoplastic polymer, the natural fibers and / or regenerated fibers have a further thermoplasticity. The degradable short fibers are mixed and carded in the same manner to obtain a web. Here, the biodegradable short fibers having thermoplasticity constituting the short fiber nonwoven web are polymers having biodegradability and thermoplasticity, for example, the above-mentioned aliphatic polyester constituting the long fiber nonwoven web is a preferable material. After being subjected to ordinary melt spinning to obtain an unstretched yarn, it is subjected to a stretching treatment, and 12 to 25 threads / 25 by an indenting crimper.
It can be obtained by applying a crimp of mm, then applying an oil for spinning, performing a drying process, and cutting into a predetermined length.

The laminated nonwoven fabric of the present invention is obtained by laminating the long-fiber nonwoven web and the short-fiber nonwoven web obtained by the above-mentioned method,
Both the nonwoven webs can be integrally obtained by performing the partial hot-pressing treatment.

In the case of performing the partial hot-pressing treatment, a method for forming a dot-like fusion zone between the long fibers by using a heated embossing roll and a metal roll having a smooth surface, or an ultrasonic fusion device The method of applying a high frequency wave by ultrasonic waves on the pattern roll by using the method of forming a point-like fused region between the long fibers of the pattern part is adopted. At this time, as described above, when the short fiber non-woven web is composed of only natural fibers and / or regenerated fibers, partial heat pressure welding is performed using an ultrasonic fusing device, and the short fiber non-woven web is Fiber and /
Alternatively, when the recycled fiber and the biodegradable thermoplastic short fiber are used, it is important to carry out partial thermal pressure welding using an ultrasonic fusing device or a hot embossing roll.

The above-mentioned partial heat-pressing means that the low-melting-point components are heat-pressed between the constituent fibers to maintain the form of the web, and at least the high-melting-point components are not melt-bonded to each other. The term "heat-pressing" is used to prevent complete fusion, and by adopting such partial heat-pressing, the biodegradability and flexibility can be exhibited while maintaining a predetermined non-woven fabric form.

The pressure contact area formed by partial heat pressure contact has a specific area with respect to the total surface area of the nonwoven web. Specifically, each heat pressure contact area has a round shape, an elliptical shape, It may have any shape such as a diamond shape, a triangular shape, a T shape, and a well shape, but it has an area of 0.07 to 1.5 mm ² and its density, that is, the pressure contact density is 10 to 120 points / cm ^2. ,
It is preferably 20 to 60 points / cm ² . When the pressure contact density is less than 10 points / cm ² , the mechanical properties and dimensional stability of the resulting nonwoven fabric are not improved, and conversely, when the pressure contact density exceeds 120 points / cm ² , flexibility and bulkiness are increased. It does not improve and neither is preferable. Further, the ratio of the area of the total heat pressure contact area to the total surface area of the nonwoven web, that is, the pressure contact area ratio is 3 to 40%, preferably 4 to 30%. If the pressure contact area ratio is less than 3%, the dimensional stability of the resulting nonwoven fabric is poor, which is not preferable. Conversely, the pressure contact area ratio is 40%
When it exceeds the above range, flexibility and bulkiness of the obtained nonwoven fabric are impaired and biodegradability is deteriorated, which is not preferable.

When using a heated embossing roll,
The surface temperature of the roll, that is, the processing temperature, is preferably set to a temperature equal to or lower than the melting point of the low melting point component constituting the long fiber nonwoven web. If the melting point of the low melting point component is exceeded, not only the polymer adheres to the heat-welding apparatus and the operability is remarkably impaired, but also the texture of the nonwoven fabric becomes hard and a flexible nonwoven fabric cannot be obtained. In addition,
When the short-fiber nonwoven web contains biodegradable thermoplastic short fibers, the temperature may be lower than the melting point of the polymer component having the lowest melting point, including the polymers constituting the short-fiber nonwoven web.

When using the ultrasonic fusing device, an ultrasonic oscillator having a frequency of about 20 kHz, which is generally called a horn,
An apparatus comprising a pattern roll having a point-like or band-like convex protrusion on the circumference is employed. The pattern roll is disposed below the ultrasonic oscillator, and the long fiber non-woven web can be partially heat-sealed by passing it between the ultrasonic oscillator and the pattern roll. There may be one row or a plurality of rows of convex protrusions arranged on this pattern roll, and when the arrangement is a plurality of rows, either a parallel or staggered arrangement may be used.

The partial heat-pressing treatment may be performed either continuously or separately. Further, in the present invention, before the long fiber nonwoven web and the short fiber nonwoven web that have been spread and deposited on the movable collection surface are laminated, the long fiber nonwoven web is preliminarily heat-pressed or hot air-pressed. It is preferable to perform the adhesion treatment or the three-dimensional entanglement treatment by a known method. Accordingly, when the long fiber nonwoven web and the short fiber nonwoven web are laminated, the shape of the long fiber woven web can be preliminarily retained. However, it is important that the degree of thermal adhesion at this time is such that it does not hinder the partial thermal pressure welding after lamination in the next step.

The unit weight of the laminated nonwoven fabric of the present invention is not particularly limited because it is selected according to the purpose of use, but
Generally, the range of 10 to ²⁰⁰ g / m ² is preferable, and the range of 15 to 150 g / m ² is more preferable. When the basis weight is less than 15 g / m ² , flexibility and biodegradation rate are excellent, but mechanical strength is poor and it is not practical. vice versa,
When the basis weight exceeds 200 g / m ² , the nonwoven fabric has a hard texture and is inferior in flexibility.

[0050]

Next, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples.

In the examples, each physical property value was measured by the following methods.

Melt flow rate value (g / 10 minutes);
The temperature was measured at 190 ° C. according to the method described in ASTM-D-1238 (E). (Hereinafter referred to as MFR value)

Melting point (° C.); maximum value of melting endothermic curve obtained by using a differential scanning calorimeter DSC-2 type manufactured by Perkin Elma Co., Ltd., with sample weight of 5 mg and heating rate of 20 ° C./min. Was given as the melting point (° C.).

Crystallization temperature (° C.); using a differential scanning calorimeter DSC-2 type manufactured by Perkin Elma Co., and a sample weight of 5 m
g, the temperature giving the maximum value of the solidification exothermic curve obtained by measuring the cooling rate at 20 ° C./min was defined as the crystallization temperature (° C.).

-Unit weight (g / m ² ); 10 sample pieces having a sample length of 10 cm and a sample width of 10 cm were prepared from the sample in the standard state, equilibrated with water, and then the weight (g) of each sample piece was weighed. Then, convert the average value of the obtained values per unit area,
The basis weight (g / m ² ) was used.

Coolability: The spun yarn was visually observed and evaluated in the following four stages. A: No cohesive yarn is observed. ；: A slight amount of cohesive yarn was observed.

Δ: There is a close contact yarn, and some of the fibers are bundled. X: Most of them adhere to each other and cannot be opened.

-Opening property: The long-fiber non-woven web formed by the spun yarn discharged from the opening device is visually observed as shown in 4 below.
It was evaluated in stages. ⊚: The constituent fibers are separated, and no adhesion yarns or bundled yarns are observed.

◯: Adhesive yarns and bundling yarns are slightly observed. Δ: There is a close contact yarn and a bundled yarn, and the openability is slightly poor. X: Most of the constituent fibers are in close contact with each other and the openability is poor.

Strength of non-woven fabric (kg / 5 cm width); JI
It was measured according to the method described in S-L-1096A. That is, a sample piece 1 having a sample length of 20 cm and a sample width of 5 cm
A zero point was created, and a tensile speed of 1 was set for each sample piece in the longitudinal direction of the nonwoven fabric using a constant-speed extension-type tensile tester (Tensilon UTM-4-1-100 manufactured by Toyo Baldwin Co., Ltd.).
It was stretched at 0 cm / min, and the average value of the load values at cutting obtained was taken as the strength (kg / 5 cm width).

Biodegradability: 6 is obtained by embedding a non-woven fabric in soil.
If the nonwoven fabric does not retain its morphology after a month, or if its strength is reduced to 50% or less of the initial strength before embedding even if it retains its morphology, the biodegradation performance is If the strength is good (○), and the strength is 75% or less of the initial strength before burying, the biodegradability is normal (△), and the strength is the initial strength before burying. When it exceeded 75% of the value, the biodegradability was evaluated as poor (; x).

Delamination strength (g / 5 cm width): Prepare three sample pieces with a sample length of 15 cm and a sample width of 5 cm,
A constant-speed tensile type tensile tester (Tensilon UTM-4-
1-100), the ends of the long-fiber non-woven web and the ends of the natural-fiber non-woven web in the laminated non-woven fabric are gripped by the upper and lower chucks, and a length of 5 cm is forced at a peeling speed of 5 cm / min. The average value of the load values obtained by peeling was defined as the delamination strength (g / 5 cm width).

Water absorption (mm): JIS-L-1096
It was measured according to the Bayrec method described in 1. That is, five sample pieces having a sample length of 20 cm and a sample width of 2.5 cm were prepared, and each sample piece was pinned on a horizontal bar supported at a constant height on a water tank containing water at 20 ± 2 ° C. And hang it. Align the lower end of the sample piece in a line and lower the horizontal bar,
Make sure that m just submerges in water. The rise height (mm) of water after standing for 10 minutes was measured, and the average value was taken as water absorbency (mm).

Example 1 As a high melting point component, an MFR value of 25 g / 10 min and a melting point of 1
Polybutylene succinate having a crystallization temperature of 14 ° C. and a crystallization temperature of 75 ° C. is used as a low melting point component, but has a MFR value of 25 g / 10 min, a melting point of 102 ° C., and a crystallization temperature of 52 ° C. butylene succinate / ethylene succinate = 85/15 mol. % Of copolyester was used to produce a long fiber nonwoven web of alternating laminated composite long fibers.

That is, the above-mentioned two components were individually weighed so that the composite ratio of the high melting point component / low melting point component was 1/1 (weight ratio), and then the temperature was measured by using an individual extruder type melt extruder. Using a spinneret that melts at 180 ° C. and has a fiber cross-section (round shape / total number of laminations 8) as shown in FIG.
The alternately laminated composite long fibers were melt-spun at a single hole discharge rate of 1.9 g / min. After the spun yarn was cooled by a cooling device, it was pulled and thinned by an air sucker installed below the spinneret at a pulling speed of 4200 m / min, and was taken out. Next, the web was opened with a known fiber-opening device, and was opened and deposited on a moving screen conveyor as a web made of composite long fibers having a single yarn fineness of 4.1 denier. Then, the obtained web was preliminarily heat-pressed to prepare a long fiber non-woven web having a basis weight of 25 g / m ² . Temporary heat pressure welding conditions are engraved patterns with an area of 0.6 mm ² and a pressure contact density of 20 points / cm.
^{2. Using} an embossing roll with a pressure contact area ratio of 15% and a metal roll with a smooth surface, the heat pressure contact temperature is 55 ° C.
Then, pseudo-hot pressure welding was performed.

On the other hand, bleached cotton is used as the short fiber non-woven web, and the basis weight is 25 by a random card machine.
A card web of g / m ² was prepared. The long-fiber non-woven web and the short-fiber non-woven web thus obtained were laminated and partially heat-pressed by an ultrasonic fusing device to obtain a laminated non-woven fabric having a basis weight of 50 g / m ² . The heat-pressing condition was such that a roll arranged in an engraving pattern having an area of 0.4 mm ² and having a press-contacting area ratio of 15% was used, and the ultrasonic oscillation frequency was 19.7 kHz.
The linear pressure was 2.0 kg / cm. Table 1 shows the operability, the physical properties of the laminated nonwoven fabric, and the biodegradability.

Example 2 Under the same conditions as in Example 1 except that the single hole discharge rate was 0.6 g / min and the composite ratio of high melting point component / low melting point component was 1/3 (weight ratio). The alternately laminated composite long fibers were melt spun. After this spun yarn is cooled by a cooling device, it is pulled by an air sucker at a pulling speed of 3600 m / min and taken up, and then opened by an opening device and placed on a moving screen conveyor. A web composed of composite long fibers having a single yarn fineness of 1.5 denier was opened and deposited. Then, the obtained web was preliminarily heat-pressed under the same conditions as in Example 1 to prepare a long fiber non-woven web having a basis weight of 25 g / m ² .

Then, a short fiber non-woven web was prepared under the same conditions as in Example 1, and the obtained short fiber non-woven web and long fiber non-woven web were laminated under the same conditions as in Example 1. Partial heat pressure welding is performed with an ultrasonic fusing device, and the basis weight is 50 g.
A laminated non-woven fabric of / m ² was obtained. Table 1 shows the operability, the physical properties of the laminated nonwoven fabric, and the biodegradability.

Example 3 Under the same conditions as in Example 1, except that the single hole discharge rate was 3.2 g / min and the composite ratio of high melting point component / low melting point component was 3/1 (weight ratio). The alternately laminated composite long fibers were melt spun. After this spun yarn is cooled by a cooling device, it is pulled by an air sucker at a pulling speed of 4800 m / min to be finely drawn, and then opened by a fiber-opening device and placed on a moving screen conveyor. A web composed of composite long fibers having a single yarn fineness of 6.0 denier was opened and deposited. Then, the obtained web was preliminarily heat-pressed under the same conditions as in Example 1 to prepare a long fiber non-woven web having a basis weight of 25 g / m ² .

Then, a short fiber non-woven web was prepared under the same conditions as in Example 1, and the obtained short fiber non-woven web and long fiber non-woven web were laminated under the same conditions as in Example 1. Partial heat pressure welding is performed with an ultrasonic fusing device, and the basis weight is 50 g.
A laminated non-woven fabric of / m ² was obtained. Table 1 shows the operability, the physical properties of the laminated nonwoven fabric, and the biodegradability.

Example 4 Using the same high melting point component and low melting point component as in Example 1,
Fiber cross section as shown in Fig. 3 (trilobal type, total number of laminated layers 8)
Using a spinneret with a single hole discharge rate of 1.8 g /
Min, the traction speed of the air sucker at the same conditions as in Example 1 except that a 4000 m / min, the long fiber basis weight in the monofilament fineness 4 deniers consisting of alternating multilayer composite long fibers of 25 g / m ² non Created a woven web.

Then, a short fiber non-woven web was prepared under the same conditions as in Example 1, and the obtained short fiber non-woven web and long fiber non-woven web were laminated under the same conditions as in Example 1. Partial heat pressure welding is performed with an ultrasonic fusing device, and the basis weight is 50 g.
A laminated non-woven fabric of / m ² was obtained. Table 1 shows the operability, the physical properties of the laminated nonwoven fabric, and the biodegradability.

Example 5 A long-fiber non-woven web composed of alternately laminated composite long fibers having a basis weight of 10 g / m ² and a basis weight of 40 g which are the same as those in Example 1.
/ M consisting ² bleached cotton by laminating a short fiber nonwoven web,
Partial thermal pressure welding is performed with an ultrasonic fusing device, and the basis weight is 50
g / m ² of the laminated nonwoven fabric was obtained. The partial hot-pressing conditions were the same as in Example 1. Table 1 shows the operability, the physical properties of the laminated nonwoven fabric, and the biodegradability.

Example 6 A long-fiber non-woven web composed of alternately laminated type composite filaments having a basis weight of 40 g / m ^{2 which} is the same as that of Example 1, and a basis weight of 10 g
/ M consisting ² bleached cotton by laminating a short fiber nonwoven web,
Partial thermal pressure welding is performed with an ultrasonic fusing device, and the basis weight is 50
g / m ² of the laminated nonwoven fabric was obtained. The partial hot-pressing conditions were the same as in Example 1. Table 1 shows the operability, the physical properties of the laminated nonwoven fabric, and the biodegradability.

Example 7 0.5 wt% each of talc and titanium oxide as crystal nucleating agents was added to the high melting point component and the low melting point component, and the traction speed was 3%.
The same procedure as in Example 1 except that the speed was set to 900 m / min.
A laminated non-woven fabric of a 3-denier composite long-fiber web and a cotton-bleached cotton web was obtained. Table 1 shows the operability, the physical properties of the laminated nonwoven fabric, and the biodegradability.

Example 8 The same two components as in the long fiber web of Example 1 were used, and the same spinning temperature and composite cross section as in Example 1 were applied.
The composite ratio is 1/1 (weight ratio), melt-spinning is performed at a single hole discharge rate of 0.8 g / min, the spun yarn is cooled by a known cooling device, and then a spinning oil agent is applied to the spun yarn to give 800 m / min. A non-stretched yarn was taken out at a speed, a plurality of the unstretched yarns were combined, and stretched by a known stretching machine at a stretch ratio of 3.5 times.
Next, in the staffing box, 18 crimps / 2
After mechanical crimping of 5 mm, the fiber was cut to a fiber length of 51 mm to obtain alternate laminated type composite short fibers having biodegradability and thermal adhesiveness with a single yarn fineness of 2.8 denier.

70% by weight of this alternate laminated type composite short fiber,
Separately prepared by a conventional method, the average fineness is 1.5 denier, the average fiber length is 25 mm, and the exposed cotton is mixed with 30% by weight, and then carded using a random card machine to randomly arrange the fibers. A mixed cotton short fiber non-woven web having a basis weight of 25 g / m ² was obtained.

The obtained mixed cotton short fiber non-woven web was used in Example 1.
Was laminated on one surface of the long-fiber non-woven web and heat-bonded to obtain a laminated non-woven fabric. The hot-pressing condition was such that an embossing roll made by subjecting a long-fiber non-woven web to hot-pressing was used, and the hot-pressing temperature was set to 97.
° C. Table 2 shows the physical properties and biodegradability of the laminated nonwoven fabric.

Example 9 50% by weight of the same alternate laminated type composite short fibers as in Example 8,
A laminated non-woven fabric was obtained under the same conditions as in Example 8 except that the bleached cotton content was 50% by weight. Table 2 shows the physical properties and biodegradability of the laminated nonwoven fabric.

Example 10 30% by weight of the same alternate laminated type composite short fibers as in Example 8,
A laminated nonwoven fabric was obtained under the same conditions as in Example 8 except that the cotton bleached cotton was adjusted to 70% by weight. Table 2 shows the physical properties and biodegradability of the laminated nonwoven fabric.

[0081] the same basis weight as Comparative Example 1 Example 1 is laminated and the web layer multilayer composite long fiber nonwoven fabric and a basis weight of 25 g / m ² is formed of bleached cotton 25 g / m ^2, the heat in a heat embossing roll Fusion processing was performed to obtain a laminated nonwoven fabric having a basis weight of 50 g / m ² . The heat-pressing condition was such that a roll arranged in an engraving pattern having an area of 0.4 mm ² and having a press-contacting area ratio of 15% was used and a linear pressure of 50% was applied.
kg / cm, the processing temperature was 90 ° C. Table 2 shows the physical properties and biodegradability of the laminated nonwoven fabric.

Comparative Example 2 Using the same high-melting point component and low-melting point component as in Example 1, the high-melting point component was placed in the core part, the low-melting point component was placed in the sheath part, and the fiber cross section was a core-sheath type composite. Using a spinneret with a cross section,
Single hole discharge rate is 1.9 g / min, core / sheath composite ratio is 1 /
1 (weight ratio), the core-sheath type composite long fibers were melt-spun. After this spun yarn is cooled by a cooling device, it is pulled by an air sucker at a pulling speed of 3400 m / min and taken up, and then opened by an opening device, and is simply placed on a moving screen conveyor. A web composed of long fibers having a yarn fineness of 5 denier was opened and deposited. However, since the fiber cross section is a core-sheath type and the low melting point component is located in the sheath part, the spun yarn is in close contact with the fiber and the spreadability is poor, so that a long fiber non-woven web cannot be obtained. It was The operability is shown in Table 2.

Comparative Example 3 A long fiber non-woven web was produced by using only the same high melting point component as in Example 1 and using a spinneret having a round fiber cross section. That is, the single-phase long fibers were melt-spun at a spinning temperature of 180 ° C. and a single hole discharge rate of 1.90 g / min. After the spun yarn is cooled by a cooling device, it is pulled by an air sucker at a pulling speed of 4400 m / min to be thinned and taken out, and then opened by a fiber-opening device and put on a moving screen conveyor. A web consisting of long fibers with a yarn fineness of 3.9 denier was opened and deposited, and the basis weight was 25 g / m ^2.
A long-fiber non-woven web was prepared. The conditions of temporary hot pressing were the same as in Example 1 except that the processing temperature was 107 ° C.

Then, a short fiber non-woven web was prepared under the same conditions as in Example 1, and the obtained short fiber non-woven web and long fiber non-woven web were laminated under the same conditions as in Example 1. Partial heat pressure welding is performed with an ultrasonic fusing device, and the basis weight is 50 g.
A laminated non-woven fabric of / m ² was obtained. Table 2 shows the operability, the physical properties of the laminated nonwoven fabric, and the biodegradability.

[0085]

[Table 1]

As is clear from Table 1, since Example 1 is a laminated nonwoven fabric of the alternating laminated type composite filament and the natural fiber of the present invention, the composite filament has good cooling property and openability. It was Further, since the method of laminating the long-fiber non-woven web and the short-fiber non-woven web is ultrasonic fusion, the adhesive force between the two components is also strong, and the mechanical properties and water absorbency of the obtained laminated non-woven fabric are excellent. there were. This non-woven fabric was embedded in soil for 6 months, and then excavated and observed, it was confirmed that the non-woven fabric did not retain its form and had good biodegradability.

In Example 2, the proportion of the low melting point component was large, but the fineness was small and the alternating laminated type composite continuous fiber was applied. Therefore, like Example 1, the cooling property of the spun yarn and The spreadability was also good, and the mechanical properties and water absorption were also excellent. In addition, good results were obtained for biodegradability.

In Example 3, since the high melting point component ratio is large and the alternating laminated type composite continuous fiber is applied, the cooling property of the spun yarn and the cooling property of the spun yarn are the same as in Example 1 even if the fineness is large. The openability was good, and the mechanical properties and water absorption were also excellent. In addition, good results were obtained for biodegradability.

In Example 4, the cross-section of the fiber was a tri-leaf type alternating laminated type composite cross section, but like Example 1, the spinnability of the spun yarn was also good, and the mechanical properties were good. It was also excellent in water absorption. In addition, good results were obtained for biodegradability.

Example 5 uses both webs of Example 1,
Since the layers were laminated so that the lamination ratio was rich in natural fibers, mechanical performance was slightly inferior to that in Example 1, but better results were obtained in water absorption and biodegradability.

Example 6 uses both webs of Example 1,
Since the layers were laminated so that the lamination ratio was rich in the composite long fiber, the water absorption and biodegradability were slightly inferior to those in Example 1, but the mechanical properties were further improved.

In Example 7, since the crystal nucleating agent was contained in the polymer, the cooling property and fiber-opening property of the spun yarn were better than those of Example 1. Further, the obtained nonwoven fabric was excellent in mechanical properties and biodegradability.

[0093]

[Table 2]

As is clear from Table 2, since Example 8 is a mixed cotton type of alternating laminated type composite short fibers and cotton bleached cotton, it is possible to carry out heat pressure welding with an embossing roll, and further, alternate laminated type composite. Since it was rich in short fibers, it was slightly inferior in water absorption, but was excellent in tensile strength and peel strength.

Similarly to Example 8, Example 9 was also a mixed cotton type of alternating laminated type composite short fibers and cotton bleached cotton, and was slightly inferior in water absorbency, but was excellent in tensile strength and peel strength.

Similar to Example 8, Example 10 was also a mixed cotton type of alternating laminated type composite short fibers and cotton bleached cotton, and was excellent in water absorbency because it was rich in cotton bleached cotton.
On the other hand, in Comparative Example 1, both the webs were partially thermocompressed by the embossing roll, though the short fiber non-woven web did not contain the thermoplastic fiber, and therefore the adhesive force between the two components was weak and it was used at all. Was not something that could withstand.

Comparative Example 2 is a core-sheath type composite cross section in which the same high melting point component and low melting point component as in Example 1 are used, but the fiber cross section is out of the range of the present invention, and further the cooling property is poor. Since the melting point component was arranged in the sheath, the spun yarn was in close contact and the intended nonwoven fabric could not be obtained.

Comparative Example 3 uses the same high melting point component simple substance as in Example 1 and is a single-phase type having a fiber cross section outside the scope of the present invention. Therefore, the cooling property and openability of the spun yarn are obtained. Although all were good, the biodegradability was remarkably inferior and the intended non-woven fabric was not obtained.

[0099]

According to the present invention, since at least a natural fiber or a regenerated fiber is present as a constituent fiber of a short fiber non-woven web, the natural fiber or the regenerated fiber exerts water absorption and mechanical properties when wet. The disadvantage of poor strength of natural or recycled fibers can be reinforced by long-fiber nonwoven webs.

In the laminated nonwoven fabric of the present invention, the long fiber non-woven web is composed of an aliphatic polyester polymer, and the short fiber non-woven web is made of a natural / woven fabric such as cotton or rayon.
Since it is composed of recycled fibers or short fibers having biodegradability, and all the constituent materials can be decomposed in a natural environment, they can exhibit excellent biodegradability.

Further, according to the present invention, a plurality of high melting point components and a plurality of low melting point components are alternately laminated in the fiber cross section of the long fibers constituting the long fiber non-woven web. Moreover, since the high-melting point component and the low-melting point component are continuous in the fiber axis direction and are exposed on the fiber surface, the low-melting point component, which is inferior in biodegradability but excellent in cooling and opening properties, is subdivided. can do. This makes it possible to obtain a nonwoven fabric that is excellent in cooling properties, fiber-opening properties, and biodegradability.

The non-woven fabric of the present invention is used as a material for medical and hygiene materials such as diapers and sanitary products, wipes such as disposable hand towels and wiping cloths, disposable packaging materials, bags for household garbage collection for household use and other waste treatment. It is suitable as a material for daily life such as wood, or as an industrial material typified by agriculture, gardening, and civil engineering. Moreover, since this nonwoven fabric has biodegradability, it completely decomposes and disappears after its use, which is beneficial from the viewpoint of protecting the natural environment.
Alternatively, since it can be reused by, for example, composting it into fertilizer, it is also useful from the viewpoint of resource reuse.

[Brief description of drawings]

FIG. 1 is a schematic view of an example of a spinneret for obtaining an alternate lamination type composite continuous fiber according to the present invention.

FIG. 2 is a model view of a fiber cross section of an example of the alternately laminated composite long fibers according to the present invention.

FIG. 3 is a model view of a fiber cross section of another example of the alternately laminated type composite continuous fiber according to the present invention.

FIG. 4 is a model view of a fiber cross section of still another example of the alternately laminated type composite continuous fiber according to the present invention.

[Explanation of symbols]

 A High melting point component B Low melting point component

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display location D04H 3/14 D04H 3/14 A

Claims (16)

[Claims] 1. A first aliphatic polyester having a long-fiber non-woven web and a short-fiber non-woven web which are laminated and integrated by partial heat pressing, wherein the long-fiber non-woven web is biodegradable. Composed of a high melting point component consisting of and a low melting point component consisting of a second aliphatic polyester having a lower melting point than the high melting point component and having a biodegradability. Each of the long fibers has a plurality of high-melting point components and low-melting point components alternately laminated in the fiber cross section, and the high-melting point component and the low-melting point component are continuous in the fiber axis direction and are exposed on the fiber surface,
A laminated non-woven fabric, wherein the short fiber non-woven web contains at least a natural fiber or a regenerated fiber. 2. A non-woven short fiber web comprises natural fibers and / or
Alternatively, the laminated nonwoven fabric according to claim 1, wherein the laminated nonwoven fabric is formed of only recycled fibers. 3. A non-woven short fiber web comprises natural fibers and / or
Alternatively, the laminated nonwoven fabric according to claim 1, which is formed by mixing recycled fibers and short fibers made of a biodegradable thermoplastic polymer. 4. The laminated non-woven fabric according to claim 3, wherein the natural fibers and / or the regenerated fibers account for 30 to 70% by weight in the constituent fibers of the short fiber non-woven web. 5. The short fiber made of a thermoplastic polymer having biodegradability contains at least a low melting point component of the components constituting the long fiber non-woven web. 4. The laminated nonwoven fabric according to 4. 6. The natural fiber and / or recycled fiber is selected from cotton, ramie, silk fiber cut into short fibers, viscose rayon, copper ammonia rayon, and lyocell which is solvent-spun rayon fiber. The laminated non-woven fabric according to any one of claims 1 to 5, wherein 7. The non-woven long-fiber web and the short-fiber non-woven web have a lamination ratio of 10/90 to 90/10 (% by weight). The laminated nonwoven fabric described. 8. The total number of laminated layers of the high melting point component and the low melting point component is 4 or more, and the single yarn fineness of the alternate lamination type composite continuous fiber is 1.5 to 10 denier. Item 8. The laminated nonwoven fabric according to any one of items 1 to 7. 9. The composite ratio of high melting point component / low melting point component is 1 /
2. The weight ratio is 3 to 3/1 (weight ratio).
9. The laminated nonwoven fabric according to any one of 1 to 8. 10. Of the low melting point component and the high melting point component,
The laminated non-woven fabric according to any one of claims 1 to 9, wherein a crystal nucleating agent is added to at least the low melting point component. 11. A high melting point component comprising a biodegradable first aliphatic polyester and a low melting point component comprising a biodegradable second aliphatic polyester having a lower melting point than this high melting point component are used. A plurality of high melting point components and low melting point components are alternately laminated in the fiber cross section,
In addition, the high-melting-point component and the low-melting-point component are continuous in the fiber axis direction and are melt-spun on the alternately laminated composite long fibers that are exposed on the fiber surface. This is a non-woven web, and after laminating a short-fiber non-woven web formed of natural fibers and / or recycled fibers on this long-fiber non-woven web, ultrasonically fusion processing is applied to partially fuse both non-woven webs. A method for producing a laminated non-woven fabric, which comprises wearing and integrating. 12. A high melting point component comprising a first aliphatic polyester having biodegradability and a low melting point component comprising a second aliphatic polyester having a lower melting point than the high melting point component are used. A plurality of high melting point components and low melting point components are alternately laminated in the fiber cross section,
Moreover, the high-melting-point component and the low-melting-point component are continuous in the fiber axis direction and are melt-spun of the alternately laminated composite long fibers that are exposed on the fiber surface, and the alternately laminated long composite fibers are drawn and thinned. A non-woven web, and a short-fiber non-woven web formed by mixing natural fibers and / or recycled fibers with short fibers made of a thermoplastic polymer having biodegradability is laminated on the long-fiber non-woven web. A method for producing a laminated non-woven fabric, characterized in that the two nonwoven webs are integrated with each other by subjecting the two nonwoven webs to a heat-pressing treatment. 13. The laminate according to claim 12, wherein the long-fiber non-woven web and the short-fiber non-woven web are partially thermocompressed by an embossing roll at a temperature equal to or lower than the melting point of the low-melting point component. Nonwoven fabric manufacturing method. 14. The laminated non-woven fabric according to claim 12, wherein the long fiber non-woven web and the short fiber non-woven web are partially heat-pressed by an ultrasonic fusing device using an ultrasonic oscillator. Manufacturing method. 15. A long fiber non-woven fabric is obtained by subjecting a long fiber non-woven web to temporary hot pressing, hot air bonding or three-dimensional entanglement treatment before laminating the long fiber non-woven web and the natural fiber non-woven web. The method for producing a laminated nonwoven fabric according to any one of claims 11 to 14, characterized in that the shape of the woven web is retained. 16. A low melting point component or a high melting point component,
The method for producing a laminated nonwoven fabric according to any one of claims 11 to 15, wherein a crystal nucleating agent is added to at least the low melting point component.