JPH1046462A - Biodegradable conjugated continuous filament nonwoven fabric - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prepare a conjugated continuous filament nonwoven fabric, excellent in flexibility, formation, biodegradability and strength and capable of controlling the spinnability and biodegradability. SOLUTION: This biodegradable conjugated continuous filament nonwoven fabric is prepared by carrying out the partially thermo compression bonding of a nonwoven fabric web composed of many conjugated continuous filament yarns melt spun from an aliphatic polyester resin. In this case, the sheath component of the core-sheath type conjugated continuous filament yarns is composed of a mixed resin of 60-100wt.% polybutylene succinate polymer synthesized from 1,4-butanediol and succinic acid with 40-0wt.% polybutylene succiniate adipate copolymer synthesized from the 1,4-butanediol, succinic acid and adipic acid and the core component is composed of 100wt.% polybutylene succinate adipate copolymer. The sheath component accounts for 10-90wt.% of the fiber cross section crossing the fiber axis of the conjugated continuous filament yarn at right angles.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuous filament nonwoven fabric having excellent flexibility and strength, having biodegradability, and capable of controlling the decomposition rate.
It can be used in a wide range of fields such as sanitary materials and general industrial materials.

[0002]

2. Description of the Related Art Spunbonded nonwoven fabrics using long fibers as constituent fibers are used for various purposes because they are higher in strength and relatively inexpensive than short fiber nonwoven fabrics containing short fibers as constituent fibers. As a fiber material constituting the spunbonded nonwoven fabric, polymers such as polyethylene, polypropylene, polyester, and polyamide are generally used. However, spunbonded nonwoven fabrics made of these materials are
It is not self-degrading and is very chemically stable under normal natural conditions. Accordingly, at present, disposable nonwoven fabrics are treated by incineration or landfill after use. In the case of incineration treatment, not only is a large cost required for incineration, but also, for example, in the case of a nylon-based long-fiber nonwoven fabric made of polyamide, toxic gas such as cyan gas may be generated. Pollution caused by waste plastics is also becoming a problem, and how to solve this problem of disposal of waste plastics,
It is a major social issue in terms of protection of the natural environment and living environment.

On the other hand, the landfill has a problem that the material remains chemically stable for a long time in soil because the material is chemically stable. As a method for solving such a problem, a new spunbonded nonwoven fabric that is naturally decomposed in a short period of time by using a material having spontaneous degradability has been demanded. As a polymer having biodegradability,
Polysaccharides such as chitin, proteins and polypeptides (polyamino acids) such as cut gut (intestinal tract) and regenerated collagen, poly-3-hydroxybutyrate, poly-3-hydroxyvalerate and poly-produced by microorganisms in nature. 3-
Microbial polyesters such as hydroxycaprolate and synthetic aliphatic polyesters such as polyglycolide and polylactide are known. However, when producing fibers from these polymers, there is a problem that the melt spinnability essential for spunbonding is extremely poor and processing cannot be carried out using a commonly used spunbonded nonwoven fabric production apparatus. Further, the cost of the material is extremely high, so that it is not suitable as a general disposable living material such as a disposable diaper, a sanitary material such as a cover stock for sanitary products, a wipe cloth, a packaging material and the like.

In order to solve the above problem, Japanese Patent Laid-Open No.
No. 57953 discloses a spunbonded nonwoven fabric made of polyethylene containing 3 to 30% by weight of a polycaprolactone as a biodegradable polymer. However, in this case, since polyethylene does not decompose semipermanently, it cannot be said that the spunbond nonwoven fabric is biodegradable in the original sense. Also, Japanese Patent Application Laid-Open No. 5-214648 discloses a spunbonded nonwoven fabric made of poly-ε-caprolactone and / or poly-β-propiolactone. In this case, the material can be made completely biodegradable, but the melting point of poly-ε-caprolactone is around 60 ° C. and the melting point of poly-β-propiolactone is 1
There is a problem that it is not suitable for practical materials because it is around 00 ° C. and has poor thermal stability.

Further, JP-A-7-48768, JP-A-7-34369 and JP-A-8-60513 are characterized in that a glycol and an aliphatic dicarboxylic acid or a derivative thereof are contained as constituent units. A long-fiber nonwoven fabric made of an aliphatic polyester resin is disclosed. Although this nonwoven fabric substantially solves the above-mentioned problems, it is not a practical material satisfying both spinnability and biodegradability. That is, as the aliphatic polyester suitable for melt spinning and usable for long-fiber nonwoven fabric, polybutylene succinate polymer as aliphatic polyester synthesized from 1,4-butanediol and succinic acid is melt-spun. Although a biodegradable long-fiber nonwoven fabric having good properties and excellent strength and feeling can be obtained, there is a disadvantage that the biodegradation rate is low.

On the other hand, polybutylene succinate-adipate copolymer as an aliphatic polyester synthesized from 1,4-butanediol and succinic acid and adipic acid has a high biodegradation rate, but a low crystallization rate and a low melting rate. Unless the spinning length (the distance from the exit of the die to the entrance of the ejector) is extremely long, fusion between yarns is liable to occur in a normal spun-pound nonwoven fabric manufacturing apparatus because the filament hardens slowly on the spinning line. There is a drawback that the texture of the obtained long-fiber nonwoven fabric is inferior. Further, when it is necessary to control the biodegradation rate according to the application, there is a problem that the current biodegradable long-fiber nonwoven fabric cannot be satisfied.

[0007]

In view of the above situation, the present inventors have intensively studied a nonwoven fabric which can control the biodegradation rate, has good spinnability, and is excellent in texture, flexibility and strength. As a result, the present inventors used a polybutylene succinate-adipate copolymer having extremely excellent biodegradability as a core component in a core-sheath composite long fiber nonwoven fabric,
Using a specific range of a mixed resin of a polybutylene succinate polymer and a polybutylene succinate-adipate copolymer as the sheath component, and defining the ratio of the sheath component in the fiber cross section orthogonal to the fiber axis as a specific range, these By combining these, the biodegradation rate can be controlled, and therefore a wide range of biodegradation rates can be imparted to the composite nonwoven fabric. Furthermore, the spinning properties are good, and the obtained composite nonwoven fabric has flexibility, formation, biodegradability and strength. And found that the present invention was completed. An object of the present invention is to provide a composite long-fiber nonwoven fabric which is easily decomposed by microorganisms, can control the decomposition rate thereof, and is excellent in flexibility, formation and strength.

[0008]

SUMMARY OF THE INVENTION The present invention relates to a group of continuous filament filaments produced by heating and melting a thermoplastic aliphatic polyester resin, extruding and spinning from a core-sheath composite spinneret of an extrusion spinning machine. A biodegradable core-sheath composite length obtained by stretching with high-speed air from an ejector, charging and opening, collecting and accumulating on a support to form a web, and then partially thermocompressing the web. In the fibrous nonwoven fabric, the sheath component of the core-sheath composite long fiber is a polybutylene succinate polymer 60 to 60 synthesized from 1,4-butanediol and succinic acid.
A resin mixture of 100% by weight and 40 to 0% by weight of a polybutylene succinate-adipate copolymer synthesized from 1,4-butanediol and succinic acid and adipic acid, wherein the core component is the polybutylene succinate A sheath component composed of 100% by weight of an adipate copolymer and having a sheath component of 10% of the fiber cross-sectional area orthogonal to the fiber axis of the composite long fiber;
It is a biodegradable composite long-fiber nonwoven fabric characterized by comprising -90% by weight.

[0009]

DETAILED DESCRIPTION OF THE INVENTION The thermoplastic resin used in the present invention is:
Polybutylene succinate polymer synthesized from 1,4-butanediol and succinic acid as aliphatic polyester polymer, and synthesized from 1,4-butanediol as succinic acid and adipic acid as aliphatic polyester copolymer These resins are polybutylene succinate-adipate copolymers. These resins have a melt flow rate measured by the method described in JIS K 7210 (190 ° C .; 2160 g load) in the range of 15 to 70 g / 10 minutes. Things. The polybutylene succinate-adipate copolymer and the polybutylene succinate polymer having a melt flow rate of less than 15 g / 10 minutes are not suitable because the melt viscosity is too high, and thread breakage is apt to occur frequently, making spinning impossible. On the other hand, the resin having a melt flow rate of more than 70 g / 10 minutes is not suitable because thread breakage is liable to occur and not only the feeling of the obtained composite long-fiber nonwoven fabric is lowered but also the strength is lowered.

Further, the difference between the melt flow rate of the polybutylene succinate polymer and that of the polybutylene succinate-adipate copolymer must be kept within the range of 0 to 30. If this difference exceeds 30, the spinning property is deteriorated due to distortion caused by too different melt elongation properties. In the present invention, various additives such as a lubricant, a wax, a coloring agent, and a crystallization accelerator, for example, in addition to an antioxidant, a heat stabilizer, and an ultraviolet absorber, may be added to the resin according to the present invention. Can be added in a range that does not impair the effect of the above.

[0011] In the biodegradable composite long-fiber nonwoven fabric of the present invention,
The sheath component of the core-sheath type composite long fiber includes 60 to 100% by weight of a polybrylene succinate polymer synthesized from 1,4-butanediol and succinic acid, and 1,4-butanediol, succinic acid and adipic acid. A resin mixed with 40 to 0% by weight of a polybutylene succinate-adipate copolymer synthesized from the above is used, and 100% by weight of the polybutylene succinate-adipate copolymer is used as a core component. The polybutylene succinate-adipate copolymer is a random copolymer, and has a lower crystallization rate, lower crystallinity, and a higher biodegradation rate than polybutylene succinate homopolymer. , The mixing ratio of polybutylene succinate / adipate copolymer in the sheath component is 40% by weight. Exceeds the, there is a possibility that fusion between composite long fiber filaments occurs, not suitable in the spinnability and spreadability are significantly deteriorated.

[0012] Further, in the composite long-fiber nonwoven fabric,
The sheath component occupies 10 to 9 in the fiber cross-sectional area perpendicular to the fiber axis.
0% by weight, preferably 20 to 85% by weight. When the sheath component is less than 10% by weight, the slow solidification of the resin from the polybutylene succinate-adipate copolymer constituting the core component affects the resin of the sheath component and causes the formation of the composite filament during formation of the web. There is a possibility that fusion may occur between them, and the spinnability and the spreadability are deteriorated, and only a nonwoven fabric having a poor texture can be obtained. When the sheath component occupies more than 90% by weight of the fiber cross-sectional area, the control of the biodegradation rate depends on the ratio of the resin constituting the sheath component. In other words, polybutylene succinate / adipate, which has an excellent biodegradation rate, is used. Since the maximum content of the polymer in the sheath component is 40% by weight, it is very difficult to control the biodegradation rate. The polybutylene succinate-adipate copolymer used in the present invention contains adipic acid in the range of 15 to 25 mol%, and the higher the content of adipic acid, the lower the melting point of the resin. Shows that the content of adipic acid is 20
It is 94-98 ° C at around mol%.

On the other hand, when the content of the polybutylene succinate polymer in the sheath component is, for example, 100% by weight and the sheath component occupying the fiber cross-sectional area is close to the upper limit (90% by weight), the melt spinnability is also improved. Is extremely excellent, but the rate of biodegradation is difficult to control. In this case, the polybutylene succinate-adipate copolymer (core component), which is extremely excellent in biodegradability, is taken into account in consideration of the ratio of the sheath component to the fiber cross-sectional area. It is necessary to combine with the ratio of the sheath component such that the ratio contained in all the fibers (total resin amount of the sheath component and the core component) in the fiber cross-sectional area of (1) falls within the range of 15 to 80% by weight. That is, when the sheath component is composed of 100% by weight of the polybutylene succinate copolymer, the ratio of the sheath component to the fiber cross-sectional area is at most 85% by weight. As described above, a polybutylene succinate / adipate copolymer having excellent biodegradability, which is easily fused between yarns during melt spinning to the core component, and a polybutylene succinate having excellent spinnability as the sheath component are used. By using a mixed resin of a acrylate polymer and the polybutylene succinate-adipate copolymer, by combining a mixing ratio of these resins in the sheath component and a ratio of the sheath component to the fiber cross-sectional area, melting is performed. It is very easy to produce a composite long-fiber nonwoven fabric with excellent spinnability and a biodegradation rate arbitrarily controlled within a range of 12 months, so that a biodegradation rate suitable for the intended use can be obtained without compromising other properties. Can be granted.

The fineness of the composite long fiber used in the present invention is 1
-10 denier. If the fineness of the long fiber exceeds 10 denier, the fiber diameter becomes too large, the obtained nonwoven fabric becomes hard and the texture decreases, and if the fineness is less than 1 denier, the production conditions become too severe, and a satisfactory long fiber is obtained. Not suitable because they cannot be obtained. The cross-sectional shape of the composite long fiber may be irregular or flat in addition to the circular cross-section. The basis weight of the composite long-fiber nonwoven fabric according to the present invention is 5 to 2
00 g / cm ² . Nonwoven fabric weight is 200 g / cm ²
If it exceeds, the nonwoven fabric becomes too hard, the texture becomes hard,
If the basis weight is less than 5 g / cm ² , the strength of the nonwoven fabric is too low, and it is difficult to manufacture the nonwoven fabric stably.

The composite continuous fiber of the present invention can be obtained by using a melt extrusion spinning apparatus having a known core-sheath composite spinning die for a composite continuous fiber nonwoven fabric. The mixed resin as the sheath component and the resin constituting the core component are extruded from the base for a composite long fiber, spun, stretched by high-pressure air from an ejector, and a large number of continuous long filaments thus formed. The group is triboelectrically charged by hitting the collision plate, and is opened by repulsion by the electric charge. In this case, corona discharge treatment can be performed as a charging method. A large number of uniformly opened filaments are then collected and accumulated on a support to form a web. In the present invention,
A web composed of a large number of long fibers accumulated on a support,
The fibers are heat bonded to provide self-fused areas at regular intervals. The self-fused area is formed by introducing a long fiber web accumulated on a support between a heated concavo-convex roll and a smooth roll, and applying heat and pressure to the web corresponding to the convex portion of the concavo-convex roll. Are formed by fusing.

In this case, the temperature of the roll varies depending on the mixing ratio of the mixed resin constituting the sheath component, but is a temperature lower by 5 to 35 ° C. than the melting point of the mixed resin of the sheath component. If the difference between the roll temperature and the melting point of the mixed resin is less than 5 ° C., the fibers will adhere to the roll during thermocompression treatment by the roll, causing a production trouble. Conversely, when the difference between the roll temperature and the melting point of the mixed resin exceeds 35 ° C., the formation of the self-fused portion becomes insufficient, and not only the strength of the sheet is remarkably reduced, but also fluffing is severely generated. The linear pressure when the thermocompression bonding is performed with the uneven roll and the smooth roll is 10 to 80 kg / cm, preferably 20 to 60 kg / cm. Pressure is 10kg
If it is less than / cm, the formation of the self-fused area by the thermocompression treatment may be insufficient, and if it is more than 80 kg / cm, the self-fused area may be in a film form and the texture of the nonwoven fabric may be impaired. . As a method of forming a self-fused area, a web composed of a group of continuous filament fibers that have been accumulated is introduced between an uneven roll and an ultrasonic horn,
By performing the ultrasonic treatment, it is possible to form a point fusion portion corresponding to the projection.

In the present invention, the area of each self-fusion zone is in the range of 0.03 to ⁴ mm ² . If the area of the self-fusion area is less than 0.03 mm ² , the sheet strength will be insufficient. Conversely, if the area of the self-fusion area exceeds 4 mm ² , the sheet will be hard. The sum of the areas of the self-fused area is in the range of 2 to 30 area% of the total surface area of the long-fiber nonwoven fabric. If the total area of the self-fusing area is less than 2 area%, the strength of the nonwoven fabric is insufficient. If the self-fusing area exceeds 30 area%, the nonwoven fabric becomes hard and unsuitable. The composite long-fiber nonwoven fabric sheet obtained as described above has excellent flexibility, formation and strength, and furthermore, is subjected to microorganisms in compost, wet soil, water containing activated sludge, seawater, and the like. It has the performance of being completely decomposed with a desired decomposition rate, and is processed variously as required, and is used as a sanitary material, a medical substrate, a clothing substrate, a household substrate, an industrial substrate, etc. Used for

[0018]

EXAMPLES The present invention will be described more specifically with reference to examples below, but the present invention is of course not limited to these. In the following examples,% is% by weight unless otherwise specified.

Example 1 Polybutylene having a melt flow rate of 40 and a melting point of 114 ° C.
Succinate polymer (trade name: Bionore, Showa High Polymer)
100% sheath component, melt flow rate 3
Polyamide containing 20 mol% of adipic acid having a melting point of 96 ° C.
Butylene succinate / adipate copolymer (trade name:
(Bionore, manufactured by Showa Polymer Co., Ltd.)
Furthermore, the weight of the sheath component in the fiber cross-sectional area perpendicular to the fiber axis
Using a known extrusion spinning apparatus with a ratio of 22%,
The resin is heated and melted, and numerous fine holes in the core-sheath composite spinneret
After extruding and spinning from
And stretched by high-speed air from
And then collect and accumulate on a moving wire-like support
To form a long fiber web. Fineness of long fiber is 2.4
It was denier. Next, the long fiber web is heated to 90 ° C.
Introduced between the heated uneven roll and smooth roll,
By welding the part corresponding to the convex part of the
40g / m ^TwoWas obtained. Row at this time
The linear pressure of the oil is 40 kg / cm
The area of the fusion zone is 0.12mm^Two, Area of self-fusion area
Was 4 area% based on the total area of the nonwoven fabric. Obtained
The following test method is used to test the quality of
evaluated.

Test method (1) Microbial decomposition rate: 40 long-fiber nonwoven fabrics having a size of 10 cm × 25 cm were used outdoors in Koto-ku, Tokyo (1-10-6 Shinonome, Koto-ku, Tokyo, Shin-Oji Paper Co., Ltd. In the Shinonome Research Center), buried at a depth of 25 cm in the soil, taken out three by one every month, observed the morphological change of the non-woven fabric, the morphology varied, and the average weight loss was reduced to 50% The time (month) was measured and observed for 12 months. (2) Spinnability: The spinnability of the resin was evaluated based on the amount of yarn breakage during melt spinning. The evaluation was performed in the following five stages. 5: No yarn breakage, and spinning properties are extremely good. 4: There is almost no yarn breakage, and the spinnability is good. 3 ... The yarn breakage is a little, but it does not matter and the spinnability is normal. 2 ... Yarn breakage is considerable and spinnability is poor. 1: Very many yarn breaks and spinning properties are extremely poor. (3) Possibility of producing long-fiber nonwoven fabric: The feasibility of producing long-fiber nonwoven fabric was evaluated in the following three stages. ×: Production of long fiber nonwoven fabric is impossible. Δ: Production of long-fiber nonwoven fabric is difficult, and a good sheet cannot be obtained.・ ・ ・: Production of long-fiber nonwoven fabric is easy, and a good sheet is obtained.

(4) Formation of nonwoven fabric: The formation of the obtained long-fiber nonwoven fabric was evaluated organoleptically. The evaluation was performed in the following five stages. 5 ... The formation is extremely good. 4: The formation is good. 3: The formation is normal. 2 ... The formation is bad. 1 ... The formation is extremely bad. (5) Flexibility: The flexibility of the obtained long-fiber nonwoven fabric was evaluated organoleptically. The evaluation was performed in the following five stages. 5 ... Very good flexibility. 4: Good flexibility. 3 ... Flexibility is normal. 2 ... Poor flexibility. 1 ... very poor flexibility. (6) Tensile strength: Performed according to the method shown in JIS P 8113.

Example 2 Melt flow rate 40, 80% of a polybutylene succinate polymer having a melting point of 114 ° C. and melt flow rate 30
A mixed resin consisting of 20% of polybutylene succinate / adipate copolymer having a melting point of 96 ° C. is used as a sheath component, the above-mentioned polybutylene succinate / adipate copolymer is used as a core component, and a fiber cross-sectional area perpendicular to the fiber axis is further used. The resin is heated and melted using a known extrusion spinning apparatus with the weight ratio of the sheath component occupying 70% of the core component, and extruded and spun from many fine holes of the core-sheath composite spinneret. , And the fiber was spread on a collision plate, and then collected and accumulated on a moving wire-like support to form a long fiber web. The fineness of the long fiber was 4.4 denier. Next, this long fiber web is
Introduced between the uneven roll and the smooth roll heated to 5 ° C,
A portion corresponding to the convex portion of the concave-convex roll was fused to obtain a composite long-fiber nonwoven fabric having a basis weight of 100 g / m ² . At this time, the linear pressure of the roll was 60 kg / cm, the area of each of the obtained self-fused sections was 2.0 mm ² , and the total area of the self-fused sections was 10 area% based on the total area of the nonwoven fabric. Was. The obtained long-fiber nonwoven fabric was tested by the test method described above,
We evaluated its quality.

Example 3 Polybutylene having a melt flow rate of 40 and a melting point of 114 ° C.
90% succinate polymer and melt flow rate 30,
Polybutylene succinate and adipate with a melting point of 96 ° C
A mixed resin consisting of 10% of a polymer is used as a sheath component,
Butylene succinate-adipate copolymer 100%
As core component, further occupies fiber cross-sectional area perpendicular to fiber axis
A known extrusion spinning apparatus in which the weight ratio of the sheath component is 80%.
The resin is heated and melted using a core-sheath composite spinneret.
After extruding and spinning from a large number of micropores, the filament group is
Stretch by high-speed air with an ejector and hit the collision plate
Open and then collect on a moving wire-like support
-Accumulated to form a long fiber web. The fineness of long fibers
It was 2.1 denier. Next, this long fiber web is
Introduced between the uneven roll and the smooth roll heated to 0 ° C,
By fusing the part corresponding to the convex part of the uneven roll
24 g / m ^TwoWas obtained. this
When the linear pressure of the roll is 30 kg / cm,
The area of each self-fusion zone is 0.28mm^Two, Self fusion zone
The total area of the areas is 8% by area per total area of the nonwoven fabric.
Was. The obtained long-fiber nonwoven fabric was tested by the test method described above,
We evaluated its quality.

Example 4 A composite long-fiber nonwoven fabric was obtained in the same manner as in Example 1, except that the weight ratio of the sheath component to the fiber cross-sectional area perpendicular to the fiber axis was 83%. The obtained long-fiber nonwoven fabric was tested by the test method described above, and its quality was evaluated.

Comparative Example 1 A composite long-fiber nonwoven fabric was obtained in the same manner as in Example 1, except that the weight ratio of the sheath component to the fiber cross-sectional area perpendicular to the fiber axis was 95%. The obtained long-fiber nonwoven fabric was tested by the test method described above, and its quality was evaluated.

Comparative Example 2 Melt flow rate 40, 10% of a polybutylene succinate polymer having a melting point of 114 ° C. and melt flow rate 30
A composite long-fiber nonwoven fabric was obtained in the same manner as in Example 1, except that a mixed resin consisting of 90% of a polybutylene succinate-adipate copolymer having a melting point of 96 ° C was used as a sheath component. The obtained long-fiber nonwoven fabric was tested by the test method described above, and its quality was evaluated.

Comparative Example 3 The procedure of Example 1 was repeated except that a resin of polybutylene succinate having a melt flow rate of 5 and a resin of a polybutylene succinate-adipate copolymer having a melt flow rate of 10 were used. An attempt was made to produce a composite long-fiber nonwoven fabric, but the yarn was frequently broken and could not be spun.

Comparative Example 4 A composite long-fiber nonwoven fabric was obtained in the same manner as in Example 1, except that the fineness of the produced composite long-fiber was 12 denier.
The obtained long-fiber nonwoven fabric was tested by the test method described above, and its quality was evaluated.

The results obtained in the examples and comparative examples are shown in Table 1.

[0030]

[Table 1]

As is evident from Table 1, according to the method of the present invention, the spinning property is good, the biodegradation rate can be selected in a wide range, and the obtained composite filament nonwoven fabric has flexibility, formation, strength and biodegradability. Excellent in properties (Examples 1 to 4). On the contrary,
When a polybutylene succinate polymer having poor biodegradability is used alone (100% by weight) as a sheath component, and the weight ratio of the sheath component to the fiber cross-sectional area perpendicular to the fiber axis is 90% by weight or more, When the biodegradation rate is extremely low (Comparative Example 1) and the mixing ratio of the polybutylene succinate-adipate copolymer in the sheath component exceeds 40% (Comparative Example 2), the spinnability becomes poor and a flexible nonwoven fabric is obtained. I couldn't. On the other hand, when a resin having a too low melt flow rate was used as the sheath component, yarn breakage frequently occurred during melt spinning, and spinning was impossible (Comparative Example 3). If the fineness of the long fiber is too high,
The sheet was hard and the formation was poor (Comparative Example 4).

[0032]

The present invention has the effect of providing a composite nonwoven fabric which has good spinnability, can control the biodegradation rate over a wide range, and is excellent in flexibility, formation, strength and biodegradability.

Claims (1)

[Claims] 1. A thermoplastic aliphatic polyester resin is heated and melted, extruded and spun from a core-sheath composite spinneret of an extruder, and a spun continuous filament filament group is drawn by high-speed air from an ejector. A web-degradable core-sheath composite long-fiber nonwoven fabric obtained by forming a web by charging, opening the fiber, collecting and accumulating on a support, and then partially thermocompressing the web; The sheath component of long fiber is 1,4
-60 to 100% by weight of a polybutylene succinate polymer synthesized from butanediol and succinic acid;
Polybutylene succinate-adipate copolymer 40 synthesized from butanediol and succinic acid and adipic acid 40
And a core component of 100% by weight of the polybutylene succinate-adipate copolymer.
And a sheath component comprising 10 to 90% by weight of a fiber cross-sectional area orthogonal to a fiber axis of the composite continuous fiber.